Patent Publication Number: US-2023143199-A1

Title: Thermal testing system having safety feature(s) and multiple independently controlled thermoelectric coolers

Description:
BACKGROUND 
     Thermal testing systems typically include a thermoelectric cooler and a thermal controller that are configured to control a temperature of a device under test. A thermoelectric cooler is a device (e.g., solid-state active heat pump) that is capable of transferring heat between its surfaces based on electrical energy that is applied to the thermoelectric cooler. For instance, the thermoelectric cooler may be configured to transfer heat in a first direction (e.g., from a first surface to a second surface) based on receipt of a positive input voltage. The thermoelectric cooler may be configured to transfer heat in a second direction, which is opposite the first direction, (e.g., from the second surface to the first surface) based on receipt of a negative input voltage. 
     A thermal controller is a device that generates an input voltage to control a thermoelectric cooler. In conventional thermal testing systems, the thermal controller generates a pre-defined fixed voltage, meaning that a heat differential between surfaces of the thermoelectric cooler is fixed. The fixed heat differential may be less than or greater than a desired heat differential. For instance, the fixed heat differential may cause the device under test to become too hot or too cold, which may negatively affect performance or reliability of the device or other components in the thermal testing system. The pre-defined fixed voltage of a conventional thermal controller may limit a temperature range over which the device under test may be thermally tested. 
     SUMMARY 
     Various approaches are described herein for, among other things, using variable voltage sources to control respective thermoelectric coolers independently in a thermal testing environment. For instance, a first variable voltage source may select a first input voltage from multiple voltages and apply the first input voltage to a first thermoelectric cooler; a second variable voltage source may select a second input voltage, which is different from the first input voltage, from multiple voltages and apply the second input voltage to a second thermoelectric cooler, and so on. By applying the input voltages to the respective thermoelectric coolers, temperature(s) of semiconductor device(s) may be set. An amplitude of an input voltage being relatively high may result in a relatively greater temperature differential across a thermoelectric cooler that is controlled by the input voltage. The amplitude of the input voltage being relatively low may result in a relatively lesser temperature differential across the thermoelectric cooler that is controlled by the input voltage. A single thermoelectric cooler may be used to set the temperature of a semiconductor device, or multiple thermoelectric coolers may be used to collaboratively set the temperature of the semiconductor device. 
     In a first example approach, a thermal testing system includes thermoelectric coolers, a thermal controller, first heat exchanger(s), and second heat exchanger(s). Each of the thermoelectric coolers has first and second opposing surfaces. Each of the thermoelectric coolers is configured to have a temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler, which is caused by a Peltier effect, based on a respective input voltage. Each of multiple subsets of the thermoelectric coolers is positioned between a respective first heat exchanger and a respective second heat exchanger. Each subset includes at least one of the thermoelectric coolers. The thermal controller includes a multiple variable voltage sources that are configured to control the respective thermoelectric coolers independently. Each variable voltage source is configured to generate a respective input voltage that corresponds to a respective target temperature differential such that the respective input voltage causes a respective thermoelectric cooler to have the respective target temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler. Each first heat exchanger is configured to transfer heat between a respective subset of the thermoelectric coolers and a fluid. Each second heat exchanger is configured to transfer heat between a respective semiconductor device and a respective subset of the thermoelectric coolers. Each of the variable voltage sources is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler based at least in part on a determination that a fluid pump from which the fluid is received by the first heat exchanger(s) encounters a technical issue. 
     In a second example approach, a thermal testing system includes thermoelectric coolers, a thermal controller, first heat exchanger(s), second heat exchanger(s), and a processing system. Each of the thermoelectric coolers has first and second opposing surfaces. Each of the thermoelectric coolers is configured to have a temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler, which is caused by a Peltier effect, based on a respective input voltage. Each of multiple subsets of the thermoelectric coolers is positioned between a respective first heat exchanger and a respective second heat exchanger. Each subset includes at least one of the thermoelectric coolers. The thermal controller includes a multiple variable voltage sources that are configured to control the respective thermoelectric coolers independently. Each variable voltage source is configured to generate a respective input voltage that corresponds to a respective target temperature differential such that the respective input voltage causes a respective thermoelectric cooler to have the respective target temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler. Each first heat exchanger is configured to transfer heat between a respective subset of the thermoelectric coolers and a fluid. Each second heat exchanger is configured to transfer heat between a respective semiconductor device and a respective subset of the thermoelectric coolers. The processing system is configured to identify a target temperature of a designated semiconductor device by reviewing a temperature indicator that indicates the target temperature, which is manually set by a user of the thermal testing system or which is programmatically set by software. The processing system is further configured to determine whether a human or programmatic error occurs with regard to setting of the target temperature based at least in part on whether an absolute value of the target temperature is greater than or equal to a first temperature threshold. The processing system is further configured to cause each of the variable voltage sources to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on a determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. 
     In a third example approach, a thermal testing system includes thermoelectric coolers, a thermal controller, first heat exchanger(s), second heat exchanger(s), and a current sensor. Each of the thermoelectric coolers has first and second opposing surfaces. Each of the thermoelectric coolers is configured to have a temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler, which is caused by a Peltier effect, based on a respective input voltage. Each of multiple subsets of the thermoelectric coolers is positioned between a respective first heat exchanger and a respective second heat exchanger. Each subset includes at least one of the thermoelectric coolers. The thermal controller includes multiple variable voltage sources that are configured to control the respective thermoelectric coolers independently. Each variable voltage source is configured to generate a respective input voltage that corresponds to a respective target temperature differential such that the respective input voltage causes a respective thermoelectric cooler to have the respective target temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler. Each first heat exchanger is configured to transfer heat between a respective subset of the thermoelectric coolers and a fluid. Each second heat exchanger is configured to transfer heat between a respective semiconductor device and a respective subset of the thermoelectric coolers. The current sensor is configured to detect currents that are provided to the respective thermoelectric coolers. Each of the variable voltage sources is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler based at least in part on a magnitude of the current that is provided to the respective thermoelectric cooler, as detected by the current sensor, being less than or equal to a current threshold 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Moreover, it is noted that the invention is not limited to the specific embodiments described in the Detailed Description and/or other sections of this document. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES 
       The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the present invention and, together with the description, further serve to explain the principles involved and to enable a person skilled in the relevant art(s) to make and use the disclosed technologies. 
         FIGS.  1 - 4    are block diagrams of example thermal testing systems in accordance with embodiments. 
         FIGS.  5 - 9    depict flowcharts of example methods for setting temperature(s) of respective semiconductor device(s) in a thermal testing environment in accordance with embodiments. 
         FIG.  10    depicts an example computer in which at least some aspects of embodiments may be implemented. 
     
    
    
     The features and advantages of the disclosed technologies will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number. 
     DETAILED DESCRIPTION 
     I. Introduction 
     The following detailed description refers to the accompanying drawings that illustrate exemplary embodiments of the present invention. However, the scope of the present invention is not limited to these embodiments, but is instead defined by the appended claims. Thus, embodiments beyond those shown in the accompanying drawings, such as modified versions of the illustrated embodiments, may nevertheless be encompassed by the present invention. 
     References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” or the like, indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the relevant art(s) to implement such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. 
     Descriptors such as “first”, “second”, “third”, etc. are used to reference some elements discussed herein. Such descriptors are used to facilitate the discussion of the example embodiments and do not indicate a required order of the referenced elements, unless an affirmative statement is made herein that such an order is required. 
     II. Example Embodiments 
     Example embodiments described herein are capable of using variable voltage sources to control respective thermoelectric coolers independently in a thermal testing environment. For instance, a first variable voltage source may select a first input voltage from multiple voltages and apply the first input voltage to a first thermoelectric cooler; a second variable voltage source may select a second input voltage, which is different from the first input voltage, from multiple voltages and apply the second input voltage to a second thermoelectric cooler, and so on. By applying the input voltages to the respective thermoelectric coolers, temperature(s) of semiconductor device(s) may be set. An amplitude of an input voltage being relatively high may result in a relatively greater temperature differential across a thermoelectric cooler that is controlled by the input voltage. The amplitude of the input voltage being relatively low may result in a relatively lesser temperature differential across the thermoelectric cooler that is controlled by the input voltage. A single thermoelectric cooler may be used to set the temperature of a semiconductor device, or multiple thermoelectric coolers may be used to collaboratively set the temperature of the semiconductor device. 
     Example techniques described herein have a variety of benefits as compared to conventional techniques for setting temperature(s) of semiconductor device(s) in a thermal testing environment. For instance, the example techniques may be capable of controlling thermoelectric coolers independently using variable voltage sources. Each of the variable voltage sources may select an input voltage from multiple input voltages, and the input voltages may be applied to the respective thermoelectric coolers. By selecting different input voltages to control the thermoelectric coolers, the variable voltage sources may cause different temperature differentials to be generated across the respective thermoelectric coolers. By using variable voltage sources, the example techniques may be capable of setting temperature(s) of semiconductor device(s) and an amount of power thermal dissipation more accurately, precisely, and/or reliably than the conventional techniques. 
     The example techniques may increase efficiency of a thermal testing process. For instance, the example techniques may reduce a likelihood that semiconductor device(s) or thermoelectric cooler(s) will need to be replaced during thermal testing due to the semiconductor device(s) or the thermoelectric cooler(s) failing (e.g., being structurally damaged) as a result of the semiconductor device(s) or the thermoelectric cooler(s) being inadvertently heated beyond upper target temperature(s) or being inadvertently cooled below lower target temperature(s). It should be noted that reducing a likelihood of the semiconductor device(s) or the thermoelectric cooler(s) to be inadvertently heated beyond the upper target temperature(s) or to be inadvertently cooled below the lower target temperature(s) may increase performance, reliability, and/or life span of the semiconductor device(s), the thermoelectric cooler(s), or other components in the thermal testing system. Regardless, by reducing the likelihood that the semiconductor device(s) or the thermoelectric cooler(s) will need to be replaced, the example techniques may reduce a cost of thermally testing the semiconductor device(s). For instance, the cost associated with replacing the semiconductor device(s) or the thermoelectric cooler(s) due to the aforementioned circumstances may be avoided. 
     The example techniques may enable multiple semiconductor devices to be thermal tested simultaneously under different thermal conditions. For instance, input voltages applied to thermoelectric coolers associated with a first semiconductor device may be different from input voltages applied to thermoelectric coolers associated with a second semiconductor device such that a cumulative temperature differential across the thermoelectric coolers associated with the first semiconductor device and a cumulative temperature differential across the thermoelectric coolers associated with the second semiconductor device are different. By enabling multiple semiconductor devices to be thermal tested simultaneously under different thermal conditions, the additional time and cost associated with testing the semiconductor devices during different (e.g., consecutive) time periods may be avoided. 
     The example techniques may be capable of thermally testing semiconductor device(s) over a greater range of temperatures, at lower temperatures, and/or at higher temperatures than the conventional techniques. For instance, using a variable voltage source to establish a temperature differential across a thermoelectric cooler and/or using multiple thermoelectric coolers to set the temperature of a semiconductor device may enable a thermal testing system to increase the range of temperatures over which the semiconductor device may be tested, reduce a lower temperature at which the semiconductor device may be tested, and/or increase an upper temperature at which the semiconductor device may be tested. 
     A user experience of a person who oversees thermal testing of semiconductor devices may be increased, for example, by obviating a need for the person to replace semiconductor devices or thermoelectric coolers due to the semiconductor devices or the thermoelectric coolers failing as a result of being inadvertently heated beyond upper target temperature(s) or being inadvertently cooled below lower target temperature(s). The user experience of the person may be increased, for example, by obviating a need for the person to test the semiconductor devices during different time periods (e.g., in order to test the devices under different thermal conditions). By eliminating a need for the person to perform such operations, a cost of thermally testing the semiconductor devices may be reduced. For instance, time spent by a person to replace failed semiconductor devices or failed thermoelectric coolers or to test semiconductor devices at different time periods has an associated cost. By eliminating the need for these operations, the cost of thermally testing the semiconductor devices can be reduced by the labor cost associated with the person performing the operations. 
       FIG.  1    is a block diagram of an example thermal testing system  100  in accordance with an embodiment. Generally speaking, the thermal testing system  100  operates to set temperatures of respective first and second semiconductor devices  118  and  128  (e.g., for the purpose of testing operation of the semiconductor devices  118  and  128  at the respective temperatures). As shown in  FIG.  1   , the thermal testing system  100  includes a thermal controller  102 , a first thermal unit  104 , a second thermal unit  106 , a fluid pump  108 , a first semiconductor device  118 , and a second semiconductor device  128 . The first thermal unit  104  includes a first heat exchanger  112 , a first thermoelectric cooler (TEC)  114 , and a second heat exchanger  116 . The first heat exchanger  112  is configured to transfer heat between a fluid  152  and the first TEC  114 . For instance, the first heat exchanger  112  is configured such that a temperature of the first heat exchanger  112  changes to correspond to a temperature of a first surface  158  of the first TEC  114 , which is proximate the first heat exchanger  112 . If the temperature of the first surface  158  of the first TEC  114  is greater than a temperature of the fluid  152 , the heat transfers from the first surface  158  of the first TEC  114  through the first heat exchanger  112  to the fluid  152 . If the temperature of the first surface  158  of the first TEC  114  is less than the temperature of the fluid  152 , the heat transfers from the fluid  152  through the first heat exchanger  112  to the first surface  158  of the first TEC  114 . 
     The first TEC  114  has the first surface  158  and a second surface  160 . The first and second surfaces  158  and  160  are on opposite sides of the first TEC  114 . The first TEC  114  is configured to have a temperature differential between the first and second surfaces  158  and  160  that is based on a first input voltage  110 . A greater amplitude of the first input signal  110  corresponds to a greater temperature differential between the first and second surfaces  158  and  160 . A lesser amplitude of the first input signal  110  corresponds to a lesser temperature differential between the first and second surfaces  158  and  160 . In one example, the first input voltage  110  being positive may correspond to the temperature of the first surface  158  being greater than the temperature of the second surface  160 , and the first input voltage  110  being negative may correspond to the temperature of the first surface  158  being less than the temperature of the second surface  160 . In another example, the first input voltage  110  being positive may correspond to the temperature of the first surface  158  being less than the temperature of the second surface  160 , and the first input voltage  110  being negative may correspond to the temperature of the first surface  158  being greater than the temperature of the second surface  160 . 
     The second heat exchanger  116  is configured to transfer heat between the first semiconductor device  118  and the first TEC  114 . For instance, the second heat exchanger  116  is configured such that a temperature of the second heat exchanger  116  changes to correspond to the temperature of the second surface  160  of the first TEC  114 , which is proximate the second heat exchanger  116 . If the temperature of the second surface  160  of the first TEC  114  is greater than a temperature of the first semiconductor device  118 , the heat transfers from the second surface  160  of the first TEC  114  through the second heat exchanger  116  to the first semiconductor device  118 . If the temperature of the second surface  160  of the first TEC  114  is less than the temperature of the first semiconductor device  118 , the heat transfers from the first semiconductor device  118  through the second heat exchanger  116  to the second surface  160  of the first TEC  114 . 
     The first semiconductor device  118  may be controlled (e.g., by a processing system) to perform operations at any one or more temperatures, as set by the thermal testing system  100 , in accordance with a thermal testing process to determine how the first semiconductor device  118  performs at those temperature(s). For instance, the performance of the first semiconductor device  118  may be analyzed (e.g., using the processing system) to determine whether the temperature(s) affect performance of the first semiconductor device  118  and to what extent the performance of the first semiconductor device  118  is affected by the temperature(s). 
     The second thermal unit  106  includes a third heat exchanger  122 , a second TEC  124 , and a fourth heat exchanger  126 . The third heat exchanger  122  is configured to transfer heat between the fluid  152  and the second TEC  124 . For instance, the third heat exchanger  122  is configured such that a temperature of the third heat exchanger  122  changes to correspond to a temperature of a first surface  168  of the second TEC  124 , which is proximate the third heat exchanger  122 . If the temperature of the first surface  168  of the second TEC  124  is greater than a temperature of the fluid  152 , the heat transfers from the first surface  168  of the second TEC  124  through the third heat exchanger  122  to the fluid  152 . If the temperature of the first surface  168  of the second TEC  124  is less than the temperature of the fluid  152 , the heat transfers from the fluid  152  through the third heat exchanger  122  to the first surface  168  of the second TEC  124 . 
     The second TEC  124  has the first surface  168  and a second surface  170 . The first and second surfaces  168  and  170  are on opposite sides of the second TEC  124 . The second TEC  124  is configured to have a temperature differential between the first and second surfaces  168  and  170  that is based on a second input voltage  120 . A greater amplitude of the second input voltage  120  corresponds to a greater temperature differential between the first and second surfaces  168  and  170 . A lesser amplitude of the second input voltage  120  corresponds to a lesser temperature differential between the first and second surfaces  168  and  170 . In one example, the second input voltage  120  being positive may correspond to the temperature of the first surface  168  being greater than the temperature of the second surface  170 , and the second input voltage  120  being negative may correspond to the temperature of the first surface  168  being less than the temperature of the second surface  170 . In another example, the second input voltage  120  being positive may correspond to the temperature of the first surface  168  being less than the temperature of the second surface  170 , and the second input voltage  120  being negative may correspond to the temperature of the first surface  168  being greater than the temperature of the second surface  170 . 
     The fourth heat exchanger  126  is configured to transfer heat between the second semiconductor device  128  and the second TEC  124 . For instance, the fourth heat exchanger  126  is configured such that a temperature of the fourth heat exchanger  126  changes to correspond to the temperature of the second surface  170  of the second TEC  124 , which is proximate the fourth heat exchanger  126 . If the temperature of the second surface  170  of the second TEC  124  is greater than a temperature of the second semiconductor device  128 , the heat transfers from the second surface  170  of the second TEC  124  through the fourth heat exchanger  126  to the second semiconductor device  128 . If the temperature of the second surface  170  of the second TEC  124  is less than the temperature of the second semiconductor device  128 , the heat transfers from the second semiconductor device  128  through the fourth heat exchanger  126  to the second surface  170  of the second TEC  124 . 
     The second semiconductor device  128  may be controlled (e.g., by a processing system) to perform operations at any one or more temperatures, as set by the thermal testing system  100 , in accordance with a thermal testing process to determine how the second semiconductor device  128  performs at those temperature(s). For instance, the performance of the second semiconductor device  128  may be analyzed (e.g., using the processing system) to determine whether the temperature(s) affect performance of the second semiconductor device  128  and to what extent the performance of the second semiconductor device  128  is affected by the temperature(s). 
     Each of the first semiconductor device  118  and  128  may be any suitable type of semiconductor device, including but not limited to a semiconductor chip, a semiconductor sensor, and a laser. A size of the first semiconductor device  118  and a size of the second semiconductor device  128  may be same or different. 
     The first thermal unit  104  and the first semiconductor device  118  are shown to be included in a first chamber  140 , and the second thermal unit  106  and the second semiconductor device  128  are shown to be included in a second chamber  190 , for non-liming, illustrative purposes. It will be recognized that the first thermal unit  104  and the first semiconductor device  118  may not be included in the first chamber  140 . It will be further recognized that the second thermal unit  106  and the second semiconductor device  128  may not be included in the second chamber  190 . 
     The thermal controller  102  includes multiple variable voltage sources  130 , which are configured to control the first and second TECs  114  and  124  independently. For instance, the variable voltage sources  130  include a first variable voltage source that is configured to generate the first input voltage  110  to be applied to the first TEC  114 . The first input voltage  110  is configured to cause the first TEC  114  to have a first target temperature differential, which corresponds to the first input voltage  110 , between the first and second surfaces  158  and  160  of the first TEC  114 . The variable voltage sources  130  further include a second variable voltage source that is configured to generate the second input voltage  120  to be applied to the second TEC  124 . The second input voltage  110  is configured to cause the second TEC  124  to have a second target temperature differential, which corresponds to the second input voltage  120 , between the first and second surfaces  168  and  170  of the second TEC  124 . 
     The fluid pump  108  is configured to pump the fluid  152  to the first and third heat exchangers  112  and  122 . For instance, the fluid pump  108  may pump the fluid  152  through tube  154   a  to the first heat exchanger  112 . The fluid  152  may flow through the first heat exchanger  112  to enable heat to be transferred between the fluid  152  and the first heat exchanger  112 , and the fluid  152  may then return to the fluid pump  108  through tube  154   b . The fluid pump  108  may pump the fluid  152  through tube  156   a  to the third heat exchanger  122 . The fluid  152  may flow through the third heat exchanger  122  to enable heat to be transferred between the fluid  152  and the third heat exchanger  122 , and the fluid  152  may then return to the fluid pump  108  through tube  156   b . The fluid pump  108  may control the temperature of the fluid  152  that is to be provided to the first and third heat exchangers  112  and  122  to be equal to a target temperature or to be within a target range of temperatures. The fluid pump  108  may change the temperature of the fluid  152  that is received from the first and third heat exchangers  112  and  122  to be equal to the target temperature or to be within the target range of temperatures. Accordingly, the fluid pump  108  may cool or heat the fluid  152  to achieve a desired temperature. The fluid  152  may be water, for example. 
     The thermal testing system  100  is shown in  FIG.  1    to include a single fluid pump for illustrative purposes and is not intended to be limiting. It will be recognized that the thermal testing system  100  may include any suitable number of fluid pumps. For instance, in an example embodiment, the thermal testing system  100  includes two fluid pumps. In accordance with this embodiment, a first fluid pump is configured to pump a first fluid to the first heat exchanger  112 , and a second fluid pump is configured to pump a second fluid to the third heat exchanger  122 . The first fluid pump may be further configured to set a temperature of the first fluid. The second fluid pump may be further configured to set a temperature of the second fluid. A composition of the first fluid and a composition of the second fluid may be same or different. 
     It will be recognized that the thermal testing system  100  may not include one or more of the components shown in  FIG.  1   . Furthermore, the thermal testing system  100  may include components in addition to or in lieu of the any one or more of the components shown in  FIG.  1   . For instance, the thermal testing system  100  is shown to include two thermal units  104  and  106  for illustrative purposes and is not intended to be limiting. It will be recognized that the thermal testing system  100  may include any suitable number (e.g., 1, 2, 3, or 4) of thermal units. 
       FIG.  2    is a block diagram of another example thermal testing system  200 , which includes three thermal units for non-limiting, illustrative purposes, in accordance with an embodiment. Generally speaking, the thermal testing system  200  operates to set temperatures of respective first, second, and third semiconductor devices  218 ,  228 , and  238  (e.g., for the purpose of testing operation of the semiconductor devices  218 ,  228 , and  238  at the respective temperatures). As shown in  FIG.  2   , the thermal testing system  200  includes a thermal controller  202 . The thermal controller  202  includes multiple variable voltage sources  230 , which are configured to control a first TEC  214   a , a second TEC  214   b , a third TEC  224   a , a fourth TEC  224   b , a fifth TEC  234   a , and a sixth TEC  234   b  independently. For example, the variable voltage sources  230  may include a first variable voltage source that controls the first TEC  214   a , a second variable voltage source that controls the second TEC  214   b , and so on. In accordance with this example, the first variable voltage source may generate a first input voltage that causes a first target temperature differential to be created across the first TEC  214   a ; the second variable voltage source may generate a second input voltage that causes a second target temperature differential to be created across the second TEC  214   b , and so on. 
     The thermal testing system  200  further includes a first heat exchanger  212 , a first TEC  214   a , a second TEC  214   b , a second heat exchanger  216 , and the first semiconductor device  218 . The first heat exchanger  212  is configured to transfer heat between a fluid and a combination of the first and second TECs  214   a - 214   b . For instance, the first heat exchanger  212  is configured such that a temperature of the first heat exchanger  212  changes to correspond to a temperature of a first surface  258  of the first TEC  214   a , which is proximate the first heat exchanger  212 . If the temperature of the first surface  258  of the first TEC  214   a  is greater than a temperature of the fluid, the heat transfers from the first surface  258  of the first TEC  214   a  through the first heat exchanger  212  to the fluid. If the temperature of the first surface  258  of the first TEC  214   a  is less than the temperature of the fluid, the heat transfers from the fluid through the first heat exchanger  212  to the first surface  258  of the first TEC  214   a.    
     The first TEC  214   a  has the first surface  258  and a second surface  260 . The first and second surfaces  258  and  260  are on opposite sides of the first TEC  214   a . The first TEC  214   a  is configured to have a temperature differential between the first and second surfaces  258  and  260  that is based on the first input voltage from the first variable voltage source, which is included among the variable voltage sources  230 . 
     The second TEC  214   b  has a first surface  278  and a second surface  280 . The first and second surfaces  278  and  280  are on opposite sides of the second TEC  214   b . The second TEC  214   b  is configured to have a temperature differential between the first and second surfaces  278  and  280  that is based on the second input voltage from the second variable voltage source, which is included among the variable voltage sources  230 . The first and second TECs  214   a - 214   b  are positioned consecutively between the first and second heat exchangers  212  and  216  such that the first surface  278  of the second TEC  214   b  is positioned proximate the second surface  260  of the first TEC  214   a . For instance, the first surface  278  of the second TEC  214   b  may be in physical contact with the second surface  260  of the first TEC  214   a . Accordingly, a temperature of the first surface  278  of the second TEC  214   b  and a temperature of the second surface  260  of the first TEC  214   a  are same. 
     The second heat exchanger  216  is configured to transfer heat between the first semiconductor device  218  and a combination of the first and second TECs  214   a - 214   b . For instance, the second heat exchanger  216  is configured such that a temperature of the second heat exchanger  216  changes to correspond to the temperature of the second surface  280  of the second TEC  214   b , which is proximate the second heat exchanger  216 . If the temperature of the second surface  280  of the second TEC  214   b  is greater than a temperature of the first semiconductor device  218 , the heat transfers from the second surface  280  of the second TEC  214   b  through the second heat exchanger  216  to the first semiconductor device  218 . If the temperature of the second surface  280  of the second TEC  214   b  is less than the temperature of the first semiconductor device  218 , the heat transfers from the first semiconductor device  218  through the second heat exchanger  216  to the second surface  280  of the second TEC  214   b.    
     The first semiconductor device  218  may be controlled (e.g., by a processing system) to perform operations at any one or more temperatures, as set by the thermal testing system  200 , in accordance with a thermal testing process to determine how the first semiconductor device  218  performs at those temperature(s). 
     The thermal testing system  200  further includes a third heat exchanger  222 , a third TEC  224   a , a fourth TEC  224   b , a fourth heat exchanger  226 , and the second semiconductor device  228 . The third heat exchanger  222  is configured to transfer heat between the fluid and a combination of the third and fourth TECs  224   a - 224   b  similarly to a manner in which the first heat exchanger  212  transfers heat between the fluid and the combination of the first and second TECs  214   a - 214   b.    
     The third and fourth TECs  224   a - 224   b  are positioned consecutively between the third and fourth heat exchangers  222  and  226 . The third and fourth TECs  224   a - 224   b  are operable in manner similar to the first and second TECs  214   a - 214   b . For instance, each of the third and fourth TECs  224   a - 224   b  has first and second opposing surfaces. Each of the third and fourth TECs  224   a - 224   b  is configured to have a temperature differential between its first and second opposing surfaces that is based on a respective input voltage from a respective variable voltage source, which is included among the variable voltage sources  230 . For instance, the temperature differential between the first and second opposing surfaces of the third TEC  224   a  may be based on a third input voltage that is received from a third variable voltage source. The temperature differential between the first and second opposing surfaces of the fourth TEC  224   b  may be based on a fourth input voltage that is received from a fourth variable voltage source. The second surface of the third TEC  224   a  is proximate the first surface of the fourth TEC  224   b , which causes a temperature of the second surface of the third TEC  224   a  and a temperature of the first surface of the fourth TEC  224   b  to be same. 
     The fourth heat exchanger  226  is configured to transfer heat between the second semiconductor device  228  and a combination of the third and fourth TECs  224   a - 224   b  similarly to a manner in which the second heat exchanger  216  transfers heat between the first semiconductor device  218  and the combination of the first and second TECs  214   a - 214   b.    
     The second semiconductor device  228  may be controlled (e.g., by a processing system) to perform operations at any one or more temperatures, as set by the thermal testing system  200 , in accordance with a thermal testing process to determine how the second semiconductor device  228  performs at those temperature(s). 
     The thermal testing system  200  further includes a fifth heat exchanger  232 , a fifth TEC  234   a , a sixth TEC  234   b , a sixth heat exchanger  236 , and the third semiconductor device  238 . The fifth heat exchanger  232  is configured to transfer heat between the fluid and a combination of the fifth and sixth TECs  234   a - 234   b  similarly to a manner in which the first heat exchanger  212  transfers heat between the fluid and the combination of the first and second TECs  214   a - 214   b.    
     The fifth and sixth TECs  234   a - 234   b  are positioned consecutively between the fifth and sixth heat exchangers  232  and  236 . The fifth and sixth TECs  234   a - 234   b  are operable in manner similar to the first and second TECs  214   a - 214   b . For instance, each of the fifth and sixth TECs  234   a - 234   b  has first and second opposing surfaces. Each of the fifth and sixth TECs  234   a - 234   b  is configured to have a temperature differential between its first and second opposing surfaces that is based on a respective input voltage from a respective variable voltage source, which is included among the variable voltage sources  230 . For instance, the temperature differential between the first and second opposing surfaces of the fifth TEC  234   a  may be based on a fifth input voltage that is received from a fifth variable voltage source. The temperature differential between the first and second opposing surfaces of the sixth TEC  234   b  may be based on a sixth input voltage that is received from a sixth variable voltage source. The second surface of the fifth TEC  234   a  is proximate the first surface of the sixth TEC  234   b , which causes a temperature of the second surface of the fifth TEC  234   a  and a temperature of the first surface of the sixth TEC  234   b  to be same. 
     The sixth heat exchanger  236  is configured to transfer heat between the third semiconductor device  238  and a combination of the fifth and sixth TECs  234   a - 234   b  similarly to a manner in which the second heat exchanger  216  transfers heat between the first semiconductor device  218  and the combination of the first and second TECs  214   a - 214   b.    
     The third semiconductor device  238  may be controlled (e.g., by a processing system) to perform operations at any one or more temperatures, as set by the thermal testing system  200 , in accordance with a thermal testing process to determine how the third semiconductor device  238  performs at those temperature(s). 
     The thermal testing system  200  further includes a voltage controller  242 . The voltage controller  242  is a controller or a voltage source that is external to the thermal controller  202 . The voltage controller  242  may be a variable voltage source (e.g., capable of generating any of a variety of voltages), a fixed voltage source (e.g., capable of generating a single, fixed voltage), or a controller (e.g., capable of changing input voltages provided by the variable voltage sources  230 ). The voltage controller  242  may be used in combination with or in lieu of any one or more of the variable voltage sources  230  to provide input voltage(s) to any one or more of the first TEC  214   a , the second TEC  214   b , the third TEC  224   a , the fourth TEC  224   b , the fifth TEC  234   a , or the sixth TEC  234   b.    
     The thermal testing system  200  further includes a humidity sensor  244 . The humidity sensor  244  is configured to detect a relative humidity in an environment of any one or more of the first semiconductor device  218 , the second semiconductor device  228 , and/or the third semiconductor device  238 . The humidity sensor  244  is further configured to generate a signal that indicates (e.g., represents) the relative humidity that is detected by the humidity sensor  244 . 
     The thermal testing system  200  further includes a temperature sensor  246 . The temperature sensor  246  is configured to detect a temperature of the fluid and/or any one or more of the components of the thermal testing system  200  and/or an environment of any one or more of the components. For instance, the temperature sensor  246  may be configured to detect a temperature of the first heat exchanger  212 , the second heat exchanger  216 , the first semiconductor device  218 , a circuit board on which the first semiconductor device  218  is attached, the third heat exchanger  222 , the fourth heat exchanger  226 , the second semiconductor device  228 , a circuit board on which the second semiconductor device  228  is attached, the fifth heat exchanger  232 , the sixth heat exchanger  236 , the third semiconductor device  238 , and/or a circuit board on which the third semiconductor device  238  is attached. The temperature sensor  246  is further configured to generate a signal that indicates the temperature that is detected by the temperature sensor  246 . 
     The thermal testing system  200  further includes a flow sensor  248 . In an example implementation, the flow sensor  248  is configured to detect a rate at which air flows in a chamber  240  in which the first semiconductor device  218  is located. In accordance with this implementation, the flow sensor  248  is further configured to generate a signal that indicates the rate at which the air flows, as detected by the flow sensor  248 . In another example implementation, the flow sensor  248  is configured to detect a rate of flow of the fluid. In accordance with this implementation, the flow sensor  248  is further configured to generate a signal that indicates the rate at which the fluid flows, as detected by the flow sensor  248 . In yet another example implementation, the flow sensor  248  is configured to detect an amount of the fluid that is stored in a fluid pump (e.g., fluid pump  108 ). In accordance with this implementation, the flow sensor  248  is further configured to generate a signal that indicates the amount of the fluid that is stored in the fluid pump, as detected by the flow sensor  248 . 
     The thermal testing system  200  further includes a processing system  250 . An example of a processing system is a system that includes at least one processor that is capable of manipulating data in accordance with a set of instructions. For instance, a processing system may be a computer, a personal digital assistant, etc. The processing system  250  is configured to perform any of a variety of operations to facilitate thermal testing of the first semiconductor device  218 , the second semiconductor device  228 , and/or the third semiconductor device  238 . For instance, the processing system  250  may implement a thermal testing process to test operation of the first semiconductor device  218 , the second semiconductor device  228 , and/or the third semiconductor device  238  while a temperature of each semiconductor device that is being thermally tested is set to a target temperature in accordance with any one or more of the techniques described herein. 
     The thermal testing system  200  further includes a current sensor  262 . The current sensor is configured to detect currents that are provided to the first TEC  214   a , the second TEC  214   b , the third TEC  224   a , the fourth TEC  224   b , the fifth TEC  234   a , and the sixth TEC  234   b , respectively. The current sensor  262  is further configured to generate signals that indicate the currents that are detected by the current sensor  262 . 
     The thermal testing system  200  further includes a pressure sensor  264 . The pressure sensor  264  is configured to detect a pressure between the second heat exchanger  216  and the first semiconductor device  218 , a pressure between the fourth heat exchanger  226  and the second semiconductor device  228 , and a pressure between the sixth heat exchanger  236  and the third semiconductor device  238 . The pressure sensor  264  is further configured to generate signals that indicate the pressures that are detected by the pressure sensor  264 . 
     The thermal testing system  200  further includes an interface  266 . The interface  266  is configured to generate an indicator that indicates an attribute detected by any of the sensors in the thermal testing system  200 . For example, the interface  266  may generate an indicator to convey information about a relative humidity that is detected by the humidity sensor  244 . In accordance with this example, the interface  266  may generate the indicator based on a signal that indicates the relative humidity and that is received from the humidity sensor  244 . 
     In another example, the interface  266  may generate an indicator to convey information about a temperature that is detected by the temperature sensor  246 . In accordance with this example, the interface  266  may generate the indicator based on a signal that indicates the temperature and that is received from the temperature sensor  246 . 
     In yet another example, the interface  266  may generate an indicator to convey information about a rate at which air flows in a chamber (e.g., chamber  240 ), as detected by the flow sensor  248 . In accordance with this example, the interface  266  may generate the indicator based on a signal that indicates the rate and that is received from the flow sensor  248 . 
     In still another example, the interface  266  may generate an indicator to convey information about a current that is detected by the current sensor  262 . In accordance with this example, the interface  266  may generate the indicator based on a signal that indicates the current and that is received from the current sensor  262 . 
     In yet another example, the interface  266  may generate an indicator to convey information about a pressure that is detected by the pressure sensor  264 . In accordance with this example, the interface  266  may generate the indicator based on a signal that indicates the pressure and that is received from the pressure sensor  264 . 
     In an example embodiment, the temperature sensor  246  is configured to detect a temperature of each of the second heat exchanger  216 , the fourth heat exchanger  226 , and the sixth heat exchanger  236 . In further accordance with this embodiment, each of the variable voltage sources  230  is configured to not provide the respective input voltage to the respective TEC based at least in part on the temperature of the heat exchanger (i.e., the second heat exchanger  216 , the fourth heat exchanger  226 , or the sixth heat exchanger  236 ) associated with the respective TEC, as detected by the temperature sensor  246 , having an absolute value that is greater than or equal to a temperature threshold. Not providing an input voltage to a TEC may include not initiating the providing of the input voltage or discontinuing the providing of the input voltage. An input voltage may be provided to a respective TEC based on the respective voltage source being manually reset (e.g., by a user of the thermal testing system  200 ). In a first example, the absolute value of a temperature may be greater than or equal to the temperature threshold based on the temperature being a positive number and not being less than the temperature threshold. In second example, the absolute value of a temperature may be greater than or equal to the temperature threshold based on the temperature being negative and not being greater than the temperature threshold. 
     In another example embodiment, the temperature sensor  246  is configured to detect a temperature of a circuit board to which a designated semiconductor device (i.e., the first semiconductor device  218 , the second semiconductor device  228 , or the third semiconductor device  238 ) is attached. In accordance with this example, the thermal controller is configured to conditionally provide power to the circuit board. For instance, the thermal controller  202  is configured to not provide the power to the circuit board based at least in part on the temperature of the circuit board, as detected by the temperature sensor  246 , having an absolute value that is greater than or equal to a temperature threshold. Not providing the power to the circuit board may include not initiating the providing of the power or discontinuing the providing of the power. The thermal controller  202  may be configured to provide the power to the circuit board based on the thermal controller  202  being manually reset. 
     In yet another example embodiment, a fluid pump (e.g., fluid pump  108  of  FIG.  1   ) is configured to pump the fluid (e.g., fluid  152  of  FIG.  1   ) to the first heat exchanger  212 , the third heat exchanger  222 , and the fifth heat exchanger  232 . In accordance with this embodiment, the temperature sensor  246  is configured to detect a temperature of a circuit board to which a designated semiconductor device is attached. In further accordance with this embodiment, the thermal controller  202  is configured to conditionally provide power to the fluid pump. For instance, the thermal controller  202  is configured to not provide the power to the fluid pump based at least in part on the temperature of the circuit board, as detected by the temperature sensor  246 , having an absolute value that is greater than or equal to a temperature threshold. The thermal controller  202  may be configured to provide the power to the fluid pump based on the thermal controller  202  being manually reset. 
     In still another example embodiment, the humidity sensor  244  is configured to detect a relative humidity in an environment of a designated semiconductor device. In accordance with this embodiment, each of the variable voltage sources  230  that is associated with a thermal unit corresponding to the designated semiconductor device is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the relative humidity, as detected by the humidity sensor  244 , being greater than or equal to a humidity threshold. Each of the variable voltage sources  230  that is associated with the thermal unit corresponding to the designated semiconductor device may be configured to automatically resume providing the respective input voltage to the respective TEC based at least in part on the relative humidity, as detected by the humidity sensor  244 , decreasing below the humidity threshold. 
     In another example embodiment, the flow sensor  248  is configured to detect a rate at which air flows in a chamber  240  in which the first semiconductor device  218  is located. In accordance with this embodiment, each of the variable voltage sources  230  that provides an input voltage to the first TEC  214   a  or the second TEC  214   b  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the rate at which air flows in the chamber  240 , as detected by the flow sensor  248 , being greater than or equal to a rate threshold. 
     In yet another example embodiment, the first semiconductor device  218  and the second semiconductor device  228  are attached to a common (e.g., same) circuit board. In accordance with this embodiment, the processing system  250  is configured to simultaneously test the first semiconductor device  218  and the second semiconductor device  228  while a first subset of the variable voltage sources  230  controls the first and second TECs  214   a - 214   b  to have a first cumulative target temperature differential across the first and second TECs  214   a - 214   b  and a second subset of the variable voltage sources controls the third and fourth TECs  224   a - 224   b  to have a second cumulative target temperature differential across the third and fourth TECs  224   a - 224   b  that is different from the first cumulative target temperature differential. 
     In still another example embodiment, the variable voltage sources  230  include first and second variable voltage sources that are configured to set (e.g., collaboratively set) a temperature in the chamber  240  in which the first semiconductor device  218  is located to equal a target temperature by controlling the respective first and second TECs  214   a - 214   b.    
     In another example embodiment, the thermal testing system  200  further includes first, second, and third chambers configured to house the respective first, second, and third semiconductor devices  218 ,  228 , and  238  during testing of the first, second, and third semiconductor devices  218 ,  228 , and  238 . In accordance with this embodiment, subsets of the variable voltage sources  230  are configured to set respective temperatures in the chambers to equal respective target temperatures by controlling respective subsets of the TECs. For instance, a first subset of the variable voltage sources  230  may control the first and second TECs  214   a - 214   b  to set the temperature in the first chamber. A second subset of the variable voltage sources  230  may control the third and fourth TECs  224   a - 224   b  to set the temperature in the second chamber. A third subset of the variable voltage sources  230  may control the fifth and sixth TECs  234   a - 234   b  to set the temperature in the third chamber. 
     In yet another example embodiment, a fluid pump (e.g., fluid pump  108  of  FIG.  1   ) is configured to pump the fluid (e.g., fluid  152  of  FIG.  1   ) to the first heat exchanger  212 , the third heat exchanger  222 , and the fifth heat exchanger  232 . In accordance with this embodiment, each of the variable voltage sources  230  is configured to discontinue providing the respective input voltage to the respective TEC (e.g., TEC  214   a ,  214   b ,  224   a ,  224   b ,  234   a , or  234   b ) based at least in part on a determination that the fluid pump encounters a technical issue. For instance, the processing system  250  may analyze any of a variety of factors (e.g., a flow rate of the fluid, an amount of the fluid in a reservoir of the fluid pump, and/or a temperature of the fluid) to determine whether the fluid pump encounters a technical issue. If the processing system  250  determines that the fluid pump has encountered a technical issue, the processing system  250  may provide a signal to the variable voltage sources  230  that causes the variable voltage sources  230  to discontinue providing the respective input voltages to the respective TECs. 
     In an aspect of this embodiment, the thermal controller  202  is configured to generate a voltage to control a circuit board to which a designated semiconductor device (e.g., the first semiconductor device  218 , the second semiconductor device  228 , or the third semiconductor device  238 ) is attached. In accordance with this aspect, the thermal controller  202  is further configured to not provide the voltage to the circuit board based at least in part on the determination that the fluid pump encounters the technical issue. 
     In another aspect of this example, the flow sensor  248  is configured to detect a rate of flow of the fluid (e.g., fluid  152  of  FIG.  1   ) that is received at the first heat exchanger  212 , the third heat exchanger  222 , and the fifth heat exchanger  232  from the fluid pump. In accordance with this aspect, each of the variable voltage sources  230  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the rate of flow of the fluid, as detected by the flow sensor  248 , being less than or equal to a flow threshold. In further accordance with this aspect, the technical issue includes the rate of flow of the fluid being less than or equal to the flow threshold. 
     In yet another aspect of this example, the flow sensor  248  is configured to detect an amount of the fluid that is stored in the fluid pump. In accordance with this aspect, each of the variable voltage sources  230  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the amount of the fluid that is stored in the fluid pump, as detected by the flow sensor  248 , being less than or equal to an amount threshold. In further accordance with this aspect, the technical issue includes the amount of the fluid that is stored in the fluid pump being less than or equal to the amount threshold. For instance, the fluid pump may store substantially no fluid. Whether the variable voltage sources  230  discontinue providing the respective input voltages may be based at least in part on whether the fluid is detected. 
     In still another aspect of this example, the temperature sensor  246  is configured to detect a temperature of the fluid. In accordance with this aspect, each of the variable voltage sources  230  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the temperature of the fluid, as detected by the temperature sensor  246 , being greater than or equal to a temperature threshold. In further accordance with this aspect, the technical issue includes the temperature of the fluid being greater than or equal to the temperature threshold. 
     In still another example embodiment, the processing system  250  is configured to identify a target temperature of a designated semiconductor device (e.g., the first semiconductor device  218 , the second semiconductor device  228 , or the third semiconductor device  238 ) by reviewing a temperature indicator that indicates the target temperature, which is manually set by a user of the thermal testing system or which is programmatically set by software. In accordance with this embodiment, the processing system  250  is further configured to determine whether a human or programmatic error occurs with regard to setting of the target temperature based at least in part on whether an absolute value of the target temperature is greater than or equal to a first temperature threshold. In further accordance with this embodiment, the processing system  250  is further configured to cause each of the variable voltage sources  230  to not provide the respective input voltage to the respective TEC (e.g., TEC  214   a ,  214   b ,  224   a ,  224   b ,  234   a , or  234   b ) based at least in part on a determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. 
     In an aspect of this embodiment, the thermal controller  202  is configured to generate a voltage to control a circuit board to which the designated semiconductor device is attached. In accordance with this aspect, the thermal controller  202  is further configured to not provide the voltage to the circuit board based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. In an example implementation, the thermal controller  202  is configured to not provide the voltage to the circuit board further based at least in part on the absolute value of the target temperature being greater than or equal to a second temperature threshold that is greater than the first temperature threshold. In accordance with this implementation, the thermal controller  202  may be configured to generate a voltage to control a fluid pump from which the fluid is received by the first heat exchanger  212 , the third heat exchanger  222 , and the fifth heat exchanger  232 . In further accordance with this implementation, the thermal controller  202  may be further configured to not provide the voltage to the fluid pump based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold and further based at least in part on the absolute value of the target temperature being greater than or equal to a third temperature threshold that is greater than the second temperature threshold. 
     In another aspect of this embodiment, the interface  266  is configured to generate an indicator, which indicates that the human or programmatic error has occurred with regard to the setting of the target temperature, based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. In an example implementation, the indicator further indicates that the variable voltage sources  230  are to be reset manually to enable the variable voltage sources  230  to provide the respective input voltages to the respective TECs. In another example implementation, the interface  266  is further configured to generate a threshold indicator, which indicates the first temperature threshold, based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. 
     In yet another aspect of this embodiment, the processing system  250  is further configured to perform a thermal testing process with regard to each of the semiconductor devices  218 ,  228 , and  238  while an absolute value of a temperature of the respective semiconductor device is less than the temperature threshold. In accordance with this aspect, the processing system  250  is further configured to discontinue performance of the thermal testing process with regard to each of the semiconductor devices  218 ,  228 , and  238  based at least in part on the absolute value of the temperature of the respective semiconductor device being greater than or equal to the temperature threshold. 
     In another example embodiment, the current sensor  262  is configured to detect currents that are provided to the respective TECs  214   a ,  214   b ,  224   a ,  224   b ,  234   a , and  234   b . In accordance with this embodiment, each of the variable voltage sources  230  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on a magnitude of the current that is provided to the respective TEC, as detected by the current sensor  262 , being less than or equal to a current threshold. For instance, the magnitude of any one or more of the currents may be substantially zero (e.g., no greater than a noise floor detected by the current sensor  262 ). It should be noted that a TEC may include multiple parallel-connected p-n cells, and a resistance of the TEC (e.g., the resistance between the first and second opposing surfaces of the TEC) may increase based on one or more of the p-n cells in the TEC failing. An increase in the resistance of a TEC results in a decrease in the current that is provided to (e.g., consumed by) the TEC. 
     In an aspect of this embodiment, the thermal controller  202  is configured to generate a voltage to control a circuit board to which a designated semiconductor device (e.g., the first semiconductor device  218 , the second semiconductor device  228 , or the third semiconductor device  238 ) is attached. In accordance with this aspect, the thermal controller  202  is further configured to not provide the voltage to the circuit board based at least in part on the magnitude of the current that is provided to the respective thermoelectric cooler, as detected by the current sensor  262 , being less than or equal to the current threshold. 
     In another aspect of this embodiment, the interface  266  is configured to generate a first indicator or a second indicator depending on whether each current in a subset (e.g., one or all) of the currents is modulated. In accordance with this aspect, the interface  266  is configured to generate the first indicator based on each current in the subset of the currents being modulated. For instance, the first indicator may include a modulated sound and/or a pulsed (e.g., blinking) light. In further accordance with this aspect, the interface  266  is configured to generate the second indicator based on each current in the subset of the currents being unmodulated. For instance, the second indicator may include an unmodulated sound and/or a non-blinking (e.g., relatively constant) light. 
     In yet another aspect of this embodiment, the interface  266  is configured to generate multiple indicators that indicate the respective magnitudes of the respective currents. 
     In still another aspect of this embodiment, the interface  266  is configured to generate an alarm regarding each of the currents that has a magnitude, as detected by the current sensor  262 , that is less than or equal to the current threshold. 
     In another aspect of this embodiment, the interface  266  is configured to generate multiple alarms related to respective current thresholds. In accordance with this aspect, the interface  266  is configured to generate each of the alarms based at least in part on a magnitude of a current, as detected by the current sensor  262 , being less than or equal to a respective current threshold. For instance, each current threshold may be different from each of the other current thresholds. 
     It will be recognized that the thermal testing system  200  may not include one or more of the components shown in  FIG.  2   . Furthermore, the thermal testing system  200  may include components in addition to or in lieu of any one or more of the components shown in  FIG.  2   . 
       FIG.  3    is a block diagram of another example thermal testing system  300 , which includes one thermal unit  304  for non-limiting, illustrative purposes, in accordance with an embodiment. Generally speaking, the thermal testing system  300  operates to set a temperature of the semiconductor device  318  (e.g., for the purpose of testing operation of the semiconductor device  318  at the temperatures). As shown in  FIG.  3   , the thermal testing system  300  includes a thermal controller  302 , the thermal unit  304 , a fluid pump  308 , and a semiconductor device  318 . The thermal unit  304  includes a first heat exchanger  312 , a first TEC  314   a , a second TEC  314   b , and a second heat exchanger  316 , which are operable in a manner similar to the first heat exchanger  212 , the first TEC  214   a , the second TEC  214   b , and the second heat exchanger  216  described above with reference to  FIG.  2   . The thermal controller  302  and the fluid pump  308  are operable in a manner similar to the thermal controller  102  and the fluid pump  108  described above with reference to  FIG.  1   . For instance, the thermal controller  302  includes multiple variable voltage sources  330 . The variable voltage sources  330  include a first variable voltage source that is configured to generate a first input voltage  310 , which is configured to control the first TEC  314   a . The variable voltage sources  330  include a second variable voltage source that is configured to generate a second input voltage  320 , which is configured to control the second TEC  314   b . The first and second TECs  314   a - 314   b  are positioned consecutively between the first and second heat exchangers  312  and  316 . The fluid pump  308  is configured to pump a fluid  352  through tubes  354  to the first heat exchanger  312 . For instance, the fluid  352  may flow through a cavity (e.g., tunnel) in the first heat exchanger  312  to change the temperature of the first heat exchanger  312 . The semiconductor device  318  may be any suitable type of semiconductor device, including but not limited to a semiconductor chip, a semiconductor sensor, and a laser. 
     It will be recognized that the thermal testing system  300  may not include one or more of the components shown in  FIG.  3   . Furthermore, the thermal testing system  300  may include components in addition to or in lieu of the any one or more of the components shown in  FIG.  3   . 
       FIG.  4    is a block diagram of another example thermal testing system  400  in accordance with an embodiment. Generally speaking, the thermal testing system  400  operates to set a temperature of a semiconductor device  418 . As shown in  FIG.  4   , the thermal testing system  400  includes a thermal controller  402 , a thermal unit  404 , a fluid pump  408 , and the semiconductor device  418 . The thermal unit  404  includes a first heat exchanger  412 , a first TEC  414   a , a second TEC  414   b , and a second heat exchanger  416 . The thermal controller  402 , the fluid pump  408 , the first heat exchanger  412 , the first TEC  414   a , the second TEC  414   b , and the second heat exchanger  416  are operable in a manner similar to the thermal controller  302 , the fluid pump  308 , the first heat exchanger  312 , the first TEC  314   a , the second TEC  314   b , and the second heat exchanger  316  described above with reference to  FIG.  3   . For instance, the variable voltage sources  430  generate first and second input voltages  410  and  420  to control the first and second TECs  414   a - 414   b . The fluid pump  408  pumps fluid  452  through tubes  454  to the first heat exchanger  412 . 
     The thermal testing system  400  further includes a voltage controller  442 . The voltage controller  442  is a controller or a voltage source that is external to the thermal controller  402 . The voltage controller  442  may be a variable voltage source (e.g., capable of generating any of a variety of voltages), a fixed voltage source (e.g., capable of generating a single, fixed voltage), or a controller (e.g., capable of changing input voltages provided by the variable voltage sources  430 ). The voltage controller  442  may be used in combination with or in lieu of any one or more of the variable voltage sources  430  to provide an input voltage to one of the first TEC  414   a  or the second TEC  414   b.    
     The thermal testing system  400  further includes a humidity sensor  444 . The humidity sensor  444  is configured to detect a relative humidity in an environment of the semiconductor device  418 . The humidity sensor  444  is further configured to generate a signal that indicates (e.g., represents) the relative humidity that is detected by the humidity sensor  444 . 
     The thermal testing system  400  further includes a temperature sensor  446 . The temperature sensor  446  is configured to detect a temperature of any one or more of the components of the thermal testing system  400  and/or an environment of any one or more of the components. For instance, the temperature sensor  446  may be configured to detect a temperature of the first heat exchanger  412 , the second heat exchanger  416 , the semiconductor device  418 , and/or a circuit board on which the semiconductor device  418  is attached. The temperature sensor  446  is further configured to generate a signal that indicates the temperature that is detected by the temperature sensor  446 . 
     The thermal testing system  400  further includes a flow sensor  448 . In an example implementation, the flow sensor  448  is configured to detect a rate at which air flows in a chamber in which the semiconductor device  418  is located. In accordance with this implementation, the flow sensor  448  is further configured to generate a signal that indicates the rate at which the air flows, as detected by the flow sensor  448 . In another example implementation, the flow sensor  448  is configured to detect a rate of flow of the fluid  452 . In accordance with this implementation, the flow sensor  448  is further configured to generate a signal that indicates the rate at which the fluid  452  flows, as detected by the flow sensor  448 . In yet another example implementation, the flow sensor  448  is configured to detect an amount of the fluid  452  that is stored in a fluid pump  408 . In accordance with this implementation, the flow sensor  448  is further configured to generate a signal that indicates the amount of the fluid  452  that is stored in the fluid pump  408 , as detected by the flow sensor  448 . 
     The thermal testing system  400  further includes a processing system  450 . The processing system  450  is configured to perform any of a variety of operations to facilitate thermal testing of the semiconductor device  418 . For instance, the processing system  450  may implement a thermal testing process to test operation of the semiconductor device  418  while a temperature of the semiconductor device  418  is set to a target temperature in accordance with any one or more of the techniques described herein. 
     The thermal testing system  400  further includes a current sensor  462 . The current sensor is configured to detect currents that are provided to the first TEC  414   a  and the second TEC  414   b , respectively. The current sensor  462  is further configured to generate signals that indicate the currents that are detected by the current sensor  462 . 
     The thermal testing system  400  further includes a pressure sensor  464 . The pressure sensor  464  is configured to detect a pressure between the second heat exchanger  416  and the semiconductor device  418 . The pressure sensor  464  is further configured to generate signals that indicate the pressure that is detected by the pressure sensor  464 . 
     The thermal testing system  400  further includes an interface  466 . The interface  466  is configured to generate an indicator that indicates an attribute detected by any of the sensors in the thermal testing system  400 . For example, the interface  466  may generate an indicator to convey information about a relative humidity that is detected by the humidity sensor  444 . In accordance with this example, the interface  466  may generate the indicator based on a signal that indicates the relative humidity and that is received from the humidity sensor  444 . 
     In another example, the interface  466  may generate an indicator to convey information about a temperature that is detected by the temperature sensor  446 . In accordance with this example, the interface  466  may generate the indicator based on a signal that indicates the temperature and that is received from the temperature sensor  446 . 
     In yet another example, the interface  466  may generate an indicator to convey information about a rate at which air flows in a chamber that includes the semiconductor device  418 , as detected by the flow sensor  448 . In accordance with this example, the interface  466  may generate the indicator based on a signal that indicates the rate and that is received from the flow sensor  448 . 
     In still another example, the interface  466  may generate an indicator to convey information about a current that is detected by the current sensor  462 . In accordance with this example, the interface  466  may generate the indicator based on a signal that indicates the current and that is received from the current sensor  462 . 
     In yet another example, the interface  466  may generate an indicator to convey information about a pressure that is detected by the pressure sensor  464 . In accordance with this example, the interface  466  may generate the indicator based on a signal that indicates the pressure and that is received from the pressure sensor  464 . 
     In an example embodiment, the variable voltage sources  430  are configured to modify a temperature of the semiconductor device  418 , which is attached to a circuit board, to equal a target temperature by generating the respective input voltages without modifying temperatures of other respective semiconductor devices that are attached to the circuit board. 
     In another example embodiment, the temperature sensor  446  is configured to detect a temperature of the second heat exchanger  416 . In accordance with this embodiment, each of the variable voltage sources  430  is configured to not provide the respective input voltage to the respective TEC based at least in part on the temperature of the second heat exchanger  416 , as detected by the temperature sensor  446 , having an absolute value that is greater than or equal to a temperature threshold. Each input voltage may thereafter be provided based on the respective variable voltage source being manually reset. 
     In yet another example embodiment, the temperature sensor  446  is configured to detect a temperature of a circuit board to which the semiconductor device  418  is attached. In accordance with this embodiment, the thermal controller  402  is configured to conditionally provide power to the circuit board. The thermal controller  402  is configured to not provide the power to the circuit board based at least in part on the temperature of the circuit board, as detected by the temperature sensor  446 , having an absolute value that is greater than or equal to a temperature threshold. The thermal controller  402  may thereafter provide the power to the circuit board based on the thermal controller  402  being manually reset. 
     In still another example embodiment, the humidity sensor  444  is configured to detect a relative humidity in an environment of the semiconductor device  418 . In accordance with this embodiment, each of the variable voltage sources  430  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the relative humidity, as detected by the humidity sensor  444 , being greater than or equal to a humidity threshold. In an aspect of this embodiment, each of the variable voltage sources  430  is configured to automatically resume providing the respective input voltage to the respective TEC based at least in part on the relative humidity, as detected by the humidity sensor  444 , decreasing below the humidity threshold. 
     In another example embodiment, the flow sensor  448  is configured to detect a rate at which air flows in a chamber in which the semiconductor device  418  is located. In accordance with this embodiment, each of the variable voltage sources  430  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the rate at which air flows in the chamber, as detected by the flow sensor  448 , being greater than or equal to a rate threshold. 
     In yet another example embodiment, the variable voltage sources  430  are configured to set a temperature in a chamber in which the semiconductor device  418  is located to equal a target temperature by controlling the respective first and second TECs  414   a - 414   b.    
     In still another example embodiment, the current sensor  462  is configured to detect at least one current from the currents that are provided to the respective first and second TECs  414   a - 414   b . In accordance with this embodiment, the interface  466  is configured to generate an indicator that indicates an attribute of the at least one current. For instance, each current may represent a working status of the respective TEC. The interface may include a light, a speaker, and/or a display via which the indicator may be provided. For example, the indicator may be a human-perceptible indicator, such as a light and/or a sound. The attribute may indicate that the at least one current is modulated (e.g., pulse-width modulated) or that the at least one current is unmodulated. The at least one current being modulated may indicate that the less than full power is being provided to the TEC(s) to which the at least one current is applied. The at least one current being unmodulated may indicate that full power is being provided to the TEC(s) to which the at least one current is applied. In an example implementation, the interface includes a light-emitting diode (LED) that is set to an “on” state if the at least one current is unmodulated and that is set to a “blinking” state if the at least one current is modulated. 
     In another example embodiment, the current sensor  462  is configured to detect currents that are provided to the respective first and second TECs  414   a - 414   b . In accordance with this embodiment, each of the variable voltage sources  430  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the current that is provided to the respective TEC, as detected by the current sensor  462 , being less than or equal to a current threshold. For instance, a current being less than or equal to the current threshold may indicate an end of life of the respective TEC. In an aspect of this embodiment, the interface  466  is configured to generate indicators such that each indicator indicates whether the respective current, as detected by the current sensor  462 , is less than or equal to the current threshold. For instance, a human who is overseeing the thermal testing process may observe the indicators to determine which TEC(s) are to be replaced. 
     In yet another example embodiment, the pressure sensor  464  is configured to detect a pressure between the second heat exchanger  416  and the semiconductor device  418 . In accordance with this embodiment, each of the variable voltage sources  430  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the pressure between the second heat exchanger  416  and the semiconductor device  418 , as detected by the pressure sensor  464 , being less than or equal to a pressure threshold. It will be recognized that each of the variable voltage sources  430  may be configured to delay initiating the providing of the respective input voltage to the respective TEC based at least in part on the pressure being less than or equal to the pressure threshold. 
     In still another example embodiment, the pressure sensor  464  is configured to detect a pressure between the second heat exchanger  416  and the semiconductor device  418 , which is attached to a circuit board. In accordance with this embodiment, the thermal controller  402  is configured to conditionally provide power to the circuit board. The thermal controller  402  is configured to not provide the power to the circuit board based at least in part on the pressure between the second heat exchanger  416  and the semiconductor device  418 , as detected by the pressure sensor  464 , being less than or equal to a pressure threshold. It will be recognized that the thermal controller  402  may be configured to delay initiating the providing of the power to the circuit board based at least in part on the pressure being less than or equal to the pressure threshold. 
     In another example embodiment, each of the variable voltage sources  430  is configured to discontinue providing the respective input voltage to the respective TEC (e.g., the first TEC  414   a  or the second TEC  414   b ) based at least in part on a determination that the fluid pump  408  encounters a technical issue. For instance, the processing system  450  may analyze any of a variety of factors (e.g., a flow rate of the fluid  452 , an amount of the fluid  452  in the fluid pump  408 , and/or a temperature of the fluid  452 ) to determine whether the fluid pump  408  encounters a technical issue. If the processing system  450  determines that the fluid pump  408  has encountered a technical issue, the processing system  450  may provide a signal to the variable voltage sources  430  that causes the variable voltage sources  430  to discontinue providing the respective first and second input voltages  410  and  420  to the respective first and second TECs  414   a - 414   b.    
     In an aspect of this embodiment, the thermal controller  402  is configured to generate a voltage to control a circuit board to which the semiconductor device  418  is attached. In accordance with this aspect, the thermal controller  402  is further configured to not provide the voltage to the circuit board based at least in part on the determination that the fluid pump  408  encounters the technical issue. 
     In another aspect of this example, the flow sensor  448  is configured to detect a rate of flow of the fluid  452 . In accordance with this aspect, each of the variable voltage sources  430  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the rate of flow of the fluid  452 , as detected by the flow sensor  448 , being less than or equal to a flow threshold. In further accordance with this aspect, the technical issue includes the rate of flow of the fluid  452  being less than or equal to the flow threshold. 
     In yet another aspect of this example, the flow sensor  448  is configured to detect an amount of the fluid  452  that is stored in the fluid pump  408 . In accordance with this aspect, each of the variable voltage sources  430  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the amount of the fluid  452  that is stored in the fluid pump  408 , as detected by the flow sensor  448 , being less than or equal to an amount threshold. In further accordance with this aspect, the technical issue includes the amount of the fluid  452  that is stored in the fluid pump  408  being less than or equal to the amount threshold. For instance, the fluid pump  408  may store substantially no fluid  452 . Whether the variable voltage sources  430  discontinue providing the respective first and second input voltages  410  and  420  may be based at least in part on whether the fluid  452  is detected. 
     In still another aspect of this example, the temperature sensor  446  is configured to detect a temperature of the fluid  452 . In accordance with this aspect, each of the variable voltage sources  430  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on the temperature of the fluid  452 , as detected by the temperature sensor  446 , being greater than or equal to a temperature threshold. In further accordance with this aspect, the technical issue includes the temperature of the fluid  452  being greater than or equal to the temperature threshold. 
     In yet another example embodiment, the processing system  450  is configured to identify a target temperature of the semiconductor device  418  by reviewing a temperature indicator that indicates the target temperature, which is manually set by a user of the thermal testing system or which is programmatically set by software. In accordance with this embodiment, the processing system  450  is further configured to determine whether a human or programmatic error occurs with regard to setting of the target temperature based at least in part on whether an absolute value of the target temperature is greater than or equal to a first temperature threshold. In further accordance with this embodiment, the processing system  450  is further configured to cause each of the variable voltage sources  430  to not provide the respective input voltage to the respective TEC based at least in part on a determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. 
     In an aspect of this embodiment, the thermal controller  402  is configured to generate a voltage to control a circuit board to which the semiconductor device  418  is attached. In accordance with this aspect, the thermal controller  402  is further configured to not provide the voltage to the circuit board based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. In an example implementation, the thermal controller  402  is configured to not provide the voltage to the circuit board further based at least in part on the absolute value of the target temperature being greater than or equal to a second temperature threshold that is greater than the first temperature threshold. In accordance with this implementation, the thermal controller  402  may be configured to generate a voltage to control the fluid pump  408 . In further accordance with this implementation, the thermal controller  402  may be further configured to not provide the voltage to the fluid pump  408  based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold and further based at least in part on the absolute value of the target temperature being greater than or equal to a third temperature threshold that is greater than the second temperature threshold. 
     In another aspect of this embodiment, the interface  466  is configured to generate an indicator, which indicates that the human or programmatic error has occurred with regard to the setting of the target temperature, based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. In an example implementation, the indicator further indicates that the variable voltage sources  430  are to be reset manually to enable the variable voltage sources  430  to provide the respective first and second input voltages  410  and  420  to the respective first and second TECs  414   a - 414   b . In another example implementation, the interface  466  is further configured to generate a threshold indicator, which indicates the first temperature threshold, based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. 
     In yet another aspect of this embodiment, the processing system  450  is further configured to perform a thermal testing process with regard to the semiconductor device  418  while an absolute value of a temperature of the semiconductor device  418  is less than the temperature threshold. In accordance with this aspect, the processing system  450  is further configured to discontinue performance of the thermal testing process with regard to the semiconductor device  418  based at least in part on the absolute value of the temperature of the semiconductor device  418  being greater than or equal to the temperature threshold. 
     In still another example embodiment, the current sensor  462  is configured to detect first and second currents that are provided to the respective first and second TECs  414   a - 414   b . In accordance with this embodiment, each of the variable voltage sources  430  is configured to discontinue providing the respective input voltage to the respective TEC based at least in part on a magnitude of the current that is provided to the respective TEC, as detected by the current sensor  462 , being less than or equal to a current threshold. 
     In an aspect of this embodiment, the thermal controller  402  is configured to generate a voltage to control a circuit board to which the semiconductor device  418  is attached. In accordance with this aspect, the thermal controller  402  is further configured to not provide the voltage to the circuit board based at least in part on the magnitude of the current that is provided to the respective TEC, as detected by the current sensor  462 , being less than or equal to the current threshold. 
     In another aspect of this embodiment, the interface  466  is configured to generate a first indicator or a second indicator depending on whether the first current and/or the second current is modulated. In accordance with this aspect, the interface  466  is configured to generate the first indicator based on the first current and/or the second current being modulated. For instance, the first indicator may include a modulated sound and/or a pulsed (e.g., blinking) light. In further accordance with this aspect, the interface  466  is configured to generate the second indicator based on the first current and/or the second current being unmodulated. For instance, the second indicator may include an unmodulated sound and/or a non-blinking (e.g., relatively constant) light. 
     In yet another aspect of this embodiment, the interface  466  is configured to generate first and second indicators that indicate the respective magnitudes of the respective first and second currents. 
     In still another aspect of this embodiment, the interface  466  is configured to generate an alarm regarding each of the first and second currents that has a magnitude, as detected by the current sensor  462 , that is less than or equal to the current threshold. 
     In another aspect of this embodiment, the interface  466  is configured to generate multiple alarms related to respective current thresholds. In accordance with this aspect, the interface  466  is configured to generate each of the alarms based at least in part on a magnitude of the first or second current, as detected by the current sensor  462 , being less than or equal to a respective current threshold. For instance, each current threshold may be different from each of the other current thresholds. 
     It will be recognized that the thermal testing system  400  may not include one or more of the components shown in  FIG.  4   . Furthermore, the thermal testing system  400  may include components in addition to or in lieu of the any one or more of the components shown in  FIG.  4   . 
       FIGS.  5 - 9    depict flowcharts  500 ,  600 ,  700 ,  800 , and  900  of example methods for setting temperature(s) of respective semiconductor device(s) in a thermal testing environment in accordance with embodiments. Flowcharts  500 ,  600 ,  700 ,  800 , and  900  may be performed by any of the thermal testing systems  100 ,  200 ,  300 , and  400  shown in respective  FIGS.  1 - 4   . For illustrative purposes, flowcharts  500 ,  600 ,  700 ,  800 , and  900  are described with respect to the thermal testing systems  100  and  200 . Further structural and operational embodiments will be apparent to persons skilled in the relevant art(s) based on the discussion regarding flowcharts  500 ,  600 ,  700 ,  800 , and  900 . 
     As shown in  FIG.  5   , the method of flowchart  500  begins at step  502 . In step  502 , thermoelectric coolers are controlled independently using (e.g., by) respective variable voltage sources. In an example implementation, the variable voltage sources  130  control the respective first and second TECs  114  and  124  independently. 
     In an example embodiment, controlling the thermoelectric coolers at step  502  includes setting (e.g., collaboratively setting), using a designated subset of the variable voltage sources, a temperature in a chamber in which a designated semiconductor device that is included among the semiconductor devices is located to equal a target temperature by controlling a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device. 
     Step  502  includes step  510 . At step  510 , temperature differentials are created between first and second opposing surfaces of the respective thermoelectric coolers in accordance with a Peltier effect by applying respective input voltages to the respective thermoelectric coolers. In an example implementation, a first variable voltage source from the variable voltage sources  130  creates a first temperature differential between the first and second surfaces  158  and  160  of the first TEC  114  by applying the first input voltage  110  to the first TEC  114 . In accordance with this implementation, a second variable voltage source from the variable voltage sources  130  creates a second temperature differential between the first and second surfaces  168  and  170  of the second TEC  124  by applying the second input voltage  120  to the second TEC  124 . 
     At step  504 , heat is transferred, using each of one or more first heat exchangers, between a fluid and a respective subset of the thermoelectric coolers that is positioned between the respective first heat exchanger and a respective second heat exchanger of one or more second heat exchangers. Each subset includes at least one of the thermoelectric coolers. In an example implementation, the first heat exchanger  112  transfers heat between the fluid  152  and the first TEC  114 , which is positioned between the first heat exchanger  112  and the second heat exchanger  116 . In accordance with this implementation, the third heat exchanger  122  transfers heat between the fluid  152  and the second TEC  124 , which is positioned between the third heat exchanger  122  and the fourth heat exchanger  126 . 
     At step  506 , heat is transferred, using each of the one or more second heat exchangers, between a respective semiconductor device and the respective subset of the thermoelectric coolers. In an example implementation, the second heat exchanger  116  transfers heat between the first semiconductor device  118  and the first TEC  114 . In accordance with this implementation, the fourth heat exchanger  126  transfers heat between the second semiconductor device  128  and the second TEC  124 . 
     At step  508 , applying each input voltage to the respective thermoelectric cooler is discontinued based at least in part on a determination that a fluid pump from which the fluid is received at the one or more first heat exchangers encounters a technical issue. In an example implementation, the variable voltage sources  130  discontinue the applying of each input voltage (e.g., first input voltage  110  or second input voltage  120 ) to the respective thermoelectric cooler (e.g., first TEC  114  or second TEC  124 ) based at least in part on a determination that the fluid pump  108  from which the fluid  152  is received at the first heat exchanger  112  and the third heat exchanger  122  encounters the technical issue. 
     In some example embodiments, one or more steps  502 ,  504 ,  506 ,  508 , and/or  510  of flowchart  500  may not be performed. Moreover, steps in addition to or in lieu of steps  502 ,  504 ,  506 ,  508 , and/or  510  may be performed. For instance, in an example embodiment, the method of flowchart  500  further includes detecting, using a temperature sensor, a temperature of a designated second heat exchanger. In an example implementation, the temperature sensor  246  detects the temperature of the designated second heat exchanger (e.g., second heat exchanger  116  or fourth heat exchanger  126 ). In accordance with this embodiment, the method of flowchart  500  further includes delaying, by each variable voltage source in a designated subset of the variable voltage sources that controls a designated subset of the thermoelectric coolers associated with the designated second heat exchanger, providing the respective input voltage to the respective thermoelectric cooler until a manual reset of the respective variable voltage source is performed, based at least in part on the temperature of the designated second heat exchanger having an absolute value that is greater than or equal to a temperature threshold. In an example implementation, each variable voltage source in a designated subset of the variable voltage sources  130  that controls a designated subset of the thermoelectric coolers (e.g., first TEC  114  or second TEC  124 ) associated with the designated second heat exchanger, delays providing the respective input voltage (e.g., first input voltage  110  or second input voltage  120 ) to the respective thermoelectric cooler until a manual reset of the respective variable voltage source is performed, based at least in part on the temperature of the designated second heat exchanger, as detected by the temperature sensor  246 , having an absolute value that is greater than or equal to the temperature threshold. For instance, the processing system  250  may cause each variable voltage source in the designated subset of the variable voltage sources  130  to delay providing the respective input voltage to the respective thermoelectric cooler until a manual reset of the respective variable voltage source is performed. 
     In another example embodiment, the method of flowchart  500  further includes detecting, using a temperature sensor, a temperature of a circuit board to which a designated semiconductor device, which is included among the semiconductor device(s), is attached. In an example implementation, the temperature sensor  246  detects the temperature of the circuit board to which the designated semiconductor device (e.g., first semiconductor device  118  or second semiconductor device  128 ) is attached. In accordance with this embodiment, the method of flowchart  500  further includes conditionally providing power to the circuit board. The conditionally providing includes not providing the power to the circuit board based at least in part on the temperature of the circuit board having an absolute value that is greater than or equal to a temperature threshold. In an example implementation, the thermal controller  102  conditionally provides the power to the circuit board, which includes not providing the power to the circuit board based at least in part on the temperature of the circuit board, as detected by the temperature sensor  246 , having an absolute value that is greater than or equal to the temperature threshold. 
     In yet another example embodiment, the method of flowchart  500  further includes detecting, using a flow sensor, a rate at which air flows in a chamber in which a designated semiconductor device, which is included among the semiconductor device(s), is located. In an example implementation, the flow sensor  248  detects the rate at which the air flows in the chamber in which the designated semiconductor device (e.g., the first semiconductor device  118  or the second semiconductor device  128 ) is located. In accordance with this embodiment, the method of flowchart  500  further includes discontinuing, by each variable voltage source associated with a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the rate at which air flows in the chamber being greater than or equal to a rate threshold. In an example implementation, each variable voltage source associated with a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device discontinues providing the respective input voltage (e.g., the first input voltage  110  or the second input voltage  120 ) to the respective thermoelectric cooler (e.g., first TEC  114  or second TEC  124 ) in the designated subset based at least in part on the rate at which air flows in the chamber, as detected by the flow sensor  248 , being greater than or equal to the rate threshold. 
     In still another example embodiment, the semiconductor device(s) comprise at least a first semiconductor device and a second semiconductor device that are attached to a common circuit board. In an example implementation, at least the first semiconductor device  118  and the second semiconductor device  128  are attached to a common circuit board. In accordance with this embodiment, the method of flowchart  500  further includes simultaneously testing at least the first semiconductor device and the second semiconductor device while a first subset of the variable voltage sources controls a first subset of the thermoelectric coolers, which is associated with the first semiconductor device, to have a first cumulative target temperature differential across the first subset of the thermoelectric coolers and a second subset of the variable voltage sources controls a second subset of the thermoelectric coolers, which is associated with the second semiconductor device, to have a second cumulative target temperature differential across the second subset of the thermoelectric coolers that is different from the first cumulative target temperature differential. In an example implementation, the processing system  250  simultaneously tests at least the first semiconductor device  118  and the second semiconductor device  128  while a first variable voltage source that is included among the variable voltage sources  130  controls the first TEC  114  to have a first target temperature differential across the first TEC  114  and a second variable voltage source that is included among the variable voltage sources  130  controls the second TEC  124  to have a second target temperature differential across the second TEC  124  that is different from the first target temperature differential. 
     In another example embodiment, the method of flowchart  500  further includes housing the semiconductor device(s) in respective chamber(s) during testing of the semiconductor device(s). In an example implementation, the first and second chambers  140  and  190  house the respective first and second semiconductor devices  118  and  128  during testing of the first and second semiconductor devices  118  and  128 . In accordance with this embodiment, controlling the thermoelectric coolers independently at step  502  includes setting, by subsets of the variable voltage sources, respective temperatures in the respective chambers to equal respective target temperatures. For instance, subsets of the variable voltage sources  130  may set respective temperatures in the respective first and second chambers  140  and  190  to equal the respective target temperatures. 
     In yet another example embodiment, the method of flowchart  500  further includes generating a voltage to control a circuit board to which a designated semiconductor device, which is included among semiconductor device(s), is attached. In an example implementation, the thermal controller  102  generates the voltage to control the circuit board to which the designated semiconductor device (e.g., the first semiconductor device  118  or the second semiconductor device  128 ) is attached. In accordance with this embodiment, the method of flowchart  500  further includes not providing the voltage to the circuit board based at least in part on the determination that the fluid pump from which the fluid is received at the one or more first heat exchangers encounters the technical issue. In an example implementation, the thermal controller  102  does not provide the voltage to the circuit board based at least in part on the determination that the fluid pump  108  from which the fluid  152  is received at the first heat exchanger  112  and the third heat exchanger  122  encounters the technical issue. 
     In still another example embodiment, the method of flowchart  500  further includes detecting a rate of flow of the fluid that is received at the one or more first heat exchangers from the fluid pump. In an example implementation, the flow sensor  248  detects the rate of flow of the fluid  152  that is received at the first heat exchanger  112  and the third heat exchanger  122  from the fluid pump  108 . In accordance with this embodiment, the method of flowchart  500  further includes discontinuing the applying of each input voltage to the respective thermoelectric cooler based at least in part on the rate of flow of the fluid being less than or equal to a flow threshold. In an example implementation, the variable voltage sources  130  discontinues the applying of the respective first and second input voltages  110  and  120  to the respective first and second TECs  114  and  124  based at least in part on the rate of the flow of the fluid  152  being less than or equal to the flow threshold. In further accordance with this embodiment, the technical issue includes the rate of flow of the fluid being less than or equal to the flow threshold. 
     In another example embodiment, the method of flowchart  500  further includes detecting an amount of the fluid that is stored in the fluid pump. In an example implementation, the flow sensor  248  detects an amount of the fluid  152  that is stored in the fluid pump  108 . In accordance with this embodiment, the method of flowchart  500  further includes discontinuing the applying of each input voltage to the respective thermoelectric cooler based at least in part on the amount of the fluid that is stored in the fluid pump being less than or equal to an amount threshold. In an example implementation, the variable voltage sources  130  discontinue the applying of the respective first and second input voltages  110  and  120  to the respective TECs  114  and  124  based at least in part on the amount of the fluid  152  that is stored in the fluid pump  108  being less than or equal to the amount threshold. In further accordance with this embodiment, the technical issue includes the amount of the fluid that is stored in the fluid pump being less than or equal to the amount threshold. 
     In yet another example embodiment, the method of flowchart  500  further includes detecting a temperature of the fluid that is received at the one or more first heat exchangers from the fluid pump. In an example implementation, the temperature sensor  246  detects a temperature of the fluid  152  that is received at the first heat exchanger  112  and the third heat exchanger  122  from the fluid pump  108 . In accordance with this embodiment, the method of flowchart  500  further includes discontinuing the applying of each input voltage to the respective thermoelectric cooler based at least in part on the temperature of the fluid being greater than or equal to a temperature threshold. In an example implementation, the variable voltage sources  130  discontinue the applying of the respective first and second input voltages  110  and  120  to the respective TECs  114  and  124  based at least in part on the temperature of the fluid  152  being greater than or equal to the temperature threshold. In further accordance with this embodiment, the technical issue includes the temperature of the fluid being greater than or equal to the temperature threshold. 
     In still another example embodiment, the method of flowchart  500  further includes one or more of the steps shown in flowchart  600  of  FIG.  6   . As shown in  FIG.  6   , the method of flowchart  600  begins at step  602 . In step  602 , the fluid is pumped, using a fluid pump, to the first heat exchanger(s). In an example implementation, the fluid pump  108  pumps the fluid  152  to the first and third heat exchangers  112  and  122 . 
     At step  604 , a temperature of a circuit board to which a designated semiconductor device, which is included among the semiconductor device(s), is attached is detected using a temperature sensor. In an example implementation, the temperature sensor  246  detects the temperature of the circuit board to which the designated semiconductor device (e.g., first semiconductor device  118  or second semiconductor device  128 ) is attached. 
     At step  606 , power is conditionally provided to the fluid pump. In an example implementation, the thermal controller  102  conditionally provides power to the fluid pump  108 . 
     Step  606  includes step  608 . At step  608 , the power is not provided to the fluid pump based at least in part on the temperature of the circuit board having an absolute value that is greater than or equal to a temperature threshold. In an example implementation, the thermal controller  102  does not provide the power to the fluid pump  108  based at least in part on the temperature of the circuit board, as detected by the temperature sensor  246 , having an absolute value that is greater than or equal to the temperature threshold. 
     In another example embodiment, the method of flowchart  500  further includes one or more of the steps shown in flowchart  700  of  FIG.  7   . As shown in  FIG.  7   , the method of flowchart  700  begins at step  702 . In step  702 , a relative humidity in an environment of a designated semiconductor device, which is included among the semiconductor device(s), is detected using a humidity sensor at a first time instance. In an example implementation, the humidity sensor  244  detects the relative humidity in the environment of the designated semiconductor device (e.g., first semiconductor device  118  or second semiconductor device  128 ) at the first time instance. 
     At step  704 , providing each input voltage to the respective thermoelectric cooler in a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device is discontinued, by each variable voltage source associated with the designated subset of the thermoelectric coolers, based at least in part on the relative humidity at the first time instance being greater than or equal to a humidity threshold. In an example implementation, each of the variable voltage sources  130  associated with the designated subset of the thermoelectric coolers (e.g., first TEC  114  or second TEC  124 ) that is associated with the designated semiconductor device discontinues providing the respective input voltage (e.g., first input voltage  110  or second input voltage  120 ) to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected by the humidity sensor  244 , at the first time instance being greater than or equal to the humidity threshold. 
     At step  706 , the relative humidity in the environment of the designated semiconductor device is detected using the humidity sensor at a second time instance. In an example implementation, the humidity sensor  244  detects the relative humidity in the environment of the designated semiconductor device at the second time instance. 
     At step  708 , providing each input voltage to the respective thermoelectric cooler in the designated subset of the thermoelectric coolers is automatically resumed, by each variable voltage source associated with the designated subset of the thermoelectric coolers, based at least in part on the relative humidity at the second time instance being less than the humidity threshold. In an example implementation, each of the variable voltage sources  130  associated with the designated subset of the thermoelectric coolers automatically resumes providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected by the humidity sensor  244 , at the second time instance being less than the humidity threshold. 
     In yet another example embodiment, step  508  in flowchart  500  is replaced with one or more of the steps shown in flowchart  800  of  FIG.  8   . As shown in  FIG.  8   , the method of flowchart  800  begins at step  802 . In step  802 , a target temperature of a designated semiconductor device, which is included among the semiconductor device(s), is identified by reviewing a temperature indicator that indicates the target temperature, which is manually set by a user of the thermal testing system or which is programmatically set by software. In an example implementation, the processing system  250  identifies the target temperature of the designated semiconductor device by reviewing the temperature indicator. The target temperature may have been manually set by a user of the thermal testing system  100  or  200  or may have been programmatically set by software (e.g., that executes on the processing system  250 ). 
     At step  804 , a determination is made whether a human or programmatic error occurs with regard to setting of the target temperature based at least in part on whether an absolute value of the target temperature is greater than or equal to a first temperature threshold. In an example implementation, the processing system  250  determines whether a human or programmatic error occurs with regard to the setting of the target temperature. For instance, the processing system  250  calculate an absolute value of the target temperature. The processing system may compare the absolute value of the target temperature and the first temperature threshold to determine whether the target temperature is greater than or equal to the first temperature threshold. 
     At step  806 , each variable voltage source is caused to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on a determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. In an example implementation, the processing system  250  causes the variable voltage sources  130  to not provide the respective first and second input voltages  110  and  120  to the respective first and second TECs  114  and  124  based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. 
     In an aspect of this embodiment, the method of flowchart  800  further includes generating a first voltage to control a circuit board to which the designated semiconductor device is attached. In an example implementation, the thermal controller  102  generates the first voltage to control the circuit board to which the designated semiconductor device is attached. In accordance with this embodiment, the method of flowchart  800  further includes not providing the first voltage to the circuit board based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. In an example implementation, the thermal controller  102  does not provide the first voltage to the circuit board based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. 
     In an example of this aspect, not providing the first voltage to the circuit board is further based at least in part on the absolute value of the target temperature being greater than or equal to a second temperature threshold that is greater than the first temperature threshold. In accordance with this example, the method of flowchart  800  may further include generating a second voltage to control a fluid pump from which the fluid is received at the one or more first heat exchangers. For instance, the thermal controller  102  may generate the second voltage to control the fluid pump  108 . In further accordance with this example, the method of flowchart  800  may further include not providing the second voltage to the fluid pump based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold and further based at least in part on the absolute value of the target temperature being greater than or equal to a third temperature threshold that is greater than the second temperature threshold. For instance, the thermal controller  102  may not provide the second voltage to the fluid pump  108  based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature and further based at least in part on the absolute value of the target temperature being greater than or equal to the third temperature threshold. 
     In another aspect of this embodiment, the method of flowchart  800  further includes generating an indicator, which indicates that the human or programmatic error has occurred with regard to the setting of the target temperature, based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. In an example implementation, the interface  266  generates the indicator. In an example, the indicator may further indicate that the variable voltage sources are to be reset manually to enable the variable voltage sources to provide the respective input voltages to the respective thermoelectric coolers. In another example, the method of flowchart  800  may further include generating a threshold indicator, which indicates the first temperature threshold, based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. For instance, the interface  266  may generate the threshold indicator. 
     In yet another aspect of this embodiment, the method of flowchart  800  further includes performing a thermal testing process with regard to each of the semiconductor device(s) while an absolute value of a temperature of the respective semiconductor device is less than the temperature threshold. In an example implementation, the processing system  250  performs the thermal testing process with regard to each of the first and second semiconductor devices  118  and  128  while an absolute value of a temperature of the respective semiconductor device is less than the temperature threshold. In accordance with this aspect, the method of flowchart  800  further includes discontinuing the performing of the thermal testing process with regard to each of the semiconductor device(s) based at least in part on the absolute value of the temperature of the respective semiconductor device being greater than or equal to the temperature threshold. In an example implementation, the processing system  250  discontinues the performing of the thermal testing process with regard to each of the first and second semiconductor devices  118  and  128  based at least in part on the absolute value of the temperature of the respective semiconductor device being greater than or equal to the temperature threshold. 
     In still another example embodiment, step  508  in flowchart  500  is replaced with one or more of the steps shown in flowchart  900  of  FIG.  9   . As shown in  FIG.  9   , the method of flowchart  900  begins at step  902 . In step  902 , currents that are provided to the respective thermoelectric coolers are detected. In an example implementation, the current sensor  262  detects the currents that are provided to the respective first and second TECs  114  and  124 . 
     At step  904 , the applying of a designated input voltage, which is included among the input voltages, to the respective thermoelectric cooler is discontinued based at least in part on a magnitude of the current that is provided to the respective thermoelectric cooler being less than or equal to a current threshold. In an example implementation, a designated variable voltage source, which is included among the variable voltage sources  130 , discontinues the applying of the designated input voltage (e.g., first input voltage  110  or second input voltage  120 ) to the respective TEC (e.g., TEC  114  or TEC  124 ) based at least in part on a magnitude of the current that is provided to the respective TEC being less than or equal to the current threshold. 
     In an aspect of this embodiment, the method of flowchart  900  further includes generating a voltage to control a circuit board to which a designated semiconductor device, which is included among the semiconductor device(s), is attached. In an example implementation, the thermal controller  102  generates the voltage to control the circuit board is attached. In accordance with this aspect, the method of flowchart  900  further includes not providing the voltage to the circuit board based at least in part on the magnitude of the current that is provided to the respective thermoelectric cooler being less than or equal to the current threshold. In an example implementation, the thermal controller  102  does not provide the voltage to the circuit board. 
     In another aspect of this embodiment, the method of flowchart  900  further includes generating a first indicator or a second indicator depending on whether a subset of the currents is modulated. For instance, if each current in the subset is modulated, the first indicator may be generated. If each current in the subset is unmodulated, the second indicator may be generated. In an example implementation, the interface  266  generates the first indicator or the second indicator depending on whether the subset of the currents is modulated. 
     In yet another aspect of this embodiment, the method of flowchart  900  further includes generating multiple indicators that indicate the respective magnitudes of the respective currents. In an example implementation, the interface  266  generates the indicators. 
     In still another aspect of this embodiment, the method of flowchart  900  further includes generating an alarm regarding each of the currents that has a magnitude that is less than or equal to the current threshold. In an example implementation, the interface  266  generates the alarm regarding each of the currents that has a magnitude that is less than or equal to the current threshold. 
     In another aspect of this embodiment, the method of flowchart  900  further includes selecting an alarm from multiple alarms that correspond to respective magnitude ranges based at least in part on the magnitude of the current that is provided to the thermoelectric cooler to which application of the designated input voltage is discontinued being included in the magnitude range to which the selected alarm corresponds. In an example implementation, the processing system  250  selects the alarm from the multiple alarms. In accordance with this aspect, the method of flowchart  900  further includes generating the alarm. In an example implementation, the interface  266  generates the alarm. For instance, the interface  266  may generate the alarm based on receipt of an instruction from the processing system  250  that instructs the interface  266  to generate the alarm. The alarms may be characterized by respective frequencies. For example, the frequency that characterizes each alarm may be different from the frequency that characterizes each other alarm. Each frequency may correspond to a rate at which the respective alarm warbles (e.g., visually or audibly) or pulses (e.g., blinks or chirps). Each frequency may correspond to a color of light that is emitted by the respective alarm or a pitch of a sound that is emitted by the respective alarm. 
     Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth herein. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods may be used in conjunction with other methods. 
     At least some of the components of each of the thermal testing systems  100 ,  200 ,  300 , and/or  400 , flowchart  500 , flowchart  600 , flowchart  700 , flowchart  800 , and/or flowchart  900  may be implemented in hardware, software, firmware, or any combination thereof. 
     For example, at least some of the components of each of the thermal testing systems  100 ,  200 ,  300 , and/or  400 , flowchart  500 , flowchart  600 , flowchart  700 , flowchart  800 , and/or flowchart  900  may be implemented, at least in part, as computer program code configured to be executed in one or more processors. 
     In another example, at least some of the components of each of the thermal testing systems  100 ,  200 ,  300 , and/or  400 , flowchart  500 , flowchart  600 , flowchart  700 , flowchart  800 , and/or flowchart  900  may be implemented, at least in part, as hardware logic/electrical circuitry. Such hardware logic/electrical circuitry may include one or more hardware logic components. Examples of a hardware logic component include but are not limited to a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), an application-specific standard product (ASSP), a system-on-a-chip system (SoC), a complex programmable logic device (CPLD), etc. For instance, a SoC may include an integrated circuit chip that includes one or more of a processor (e.g., a microcontroller, microprocessor, digital signal processor (DSP), etc.), memory, one or more communication interfaces, and/or further circuits and/or embedded firmware to perform its functions. 
     III. Further Discussion of Some Example Embodiments 
     (A1) An example thermal testing system ( FIG.  1 ,  100   ;  FIG.  2 ,  200   ;  FIG.  3 ,  300   ;  FIG.  4 ,  400   ) comprises a plurality of thermoelectric coolers ( FIG.  1 ,  114 ,  124   ;  FIG.  2 ,  214     a - 214   b ,  224   a - 224   b ,  234   a - 234   b ;  FIG.  3 ,  314     a - 314   b ;  FIG.  4 ,  414     a - 414   b ), a thermal controller ( FIG.  1 ,  102   ;  FIG.  2 ,  202   ;  FIG.  3 ,  302   ;  FIG.  4 ,  402   ), one or more first heat exchangers ( FIG.  1 ,  112 ,  122   ;  FIG.  2 ,  212 ,  222 ,  232   ;  FIG.  3 ,  312   ;  FIG.  4 ,  412   ), and one or more second heat exchangers ( FIG.  1 ,  116 ,  126   ;  FIG.  2 ,  216 ,  226 ,  236   ;  FIG.  3 ,  316   ;  FIG.  4 ,  416   ). Each thermoelectric cooler has first and second opposing surfaces. Each thermoelectric cooler is configured to have a temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler, which is caused by a Peltier effect, based on a respective input voltage ( FIG.  1 ,  110 ,  120   ;  FIG.  3 ,  310 ,  320   ;  FIG.  4 ,  410 ,  420   ). Each subset of a plurality of subsets of the thermoelectric coolers is positioned between a respective first heat exchanger of the one or more first heat exchangers and a respective second heat exchanger of the one or more second heat exchangers. Each subset includes at least one of the plurality of thermoelectric coolers. The thermal controller comprises a plurality of variable voltage sources ( FIG.  1 ,  130   ,  FIG.  2 ,  230   ;  FIG.  3 ,  330   ,  FIG.  4 ,  430   ) that are configured to control the plurality of respective thermoelectric coolers independently. Each variable voltage source is configured to generate a respective input voltage that corresponds to a respective target temperature differential such that the respective input voltage causes a respective thermoelectric cooler of the plurality of thermoelectric coolers to have the respective target temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler. Each first heat exchanger is configured to transfer heat between a respective subset of the thermoelectric coolers and a fluid ( FIG.  1 ,  152   ;  FIG.  3 ,  352   ;  FIG.  4 ,  452   ). Each second heat exchanger is configured to transfer heat between a respective semiconductor device of a one or more semiconductor devices ( FIG.  1 ,  118 ,  128   ;  FIG.  2 ,  218 ,  228 ,  238   ;  FIG.  3 ,  318   ;  FIG.  4 ,  418   ) and a respective subset of the thermoelectric coolers. Each variable voltage source is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler based at least in part on a determination that a fluid pump ( FIG.  1 ,  108   ;  FIG.  3 ,  308   ;  FIG.  4 ,  408   ) from which the fluid is received by the one or more first heat exchangers encounters a technical issue. 
     (A2) In the example thermal testing system of A1, further comprising: a temperature sensor configured to detect a temperature of each second heat exchanger; wherein each variable voltage source is configured to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on the temperature of the second heat exchanger associated with the subset of the thermoelectric coolers that includes the respective thermoelectric cooler, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (A3) In the example thermal testing system of any of A1-A2, further comprising: a temperature sensor configured to detect a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; wherein the thermal controller is configured to conditionally provide power to the circuit board, the thermal controller configured to not provide the power to the circuit board based at least in part on the temperature of the circuit board, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (A4) In the example thermal testing system of any of A1-A3, further comprising: the fluid pump configured to pump the fluid to the one or more first heat exchangers; and a temperature sensor configured to detect a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; wherein the thermal controller is configured to conditionally provide power to the fluid pump, the thermal controller configured to not provide the power to the fluid pump based at least in part on the temperature of the circuit board, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (A5) In the example thermal testing system of any of A1-A4, further comprising: a humidity sensor configured to detect a relative humidity in an environment of a designated semiconductor device of the one or more semiconductor devices; wherein each variable voltage source associated with a designated subset of the thermoelectric coolers, which is associated with the designated semiconductor device, is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected by the humidity sensor, being greater than or equal to a humidity threshold. 
     (A6) In the example thermal testing system of any of A1-A5, wherein each variable voltage source associated with the designated subset of the thermoelectric coolers is configured to automatically resume providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected by the humidity sensor, decreasing below the humidity threshold. 
     (A7) In the example thermal testing system of any of A1-A6, further comprising: a flow sensor configured to detect a rate at which air flows in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located; wherein each variable voltage source associated with a designated subset of the thermoelectric coolers, which is associated with the designated semiconductor device, is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the rate at which air flows in the chamber, as detected by the flow sensor, being greater than or equal to a rate threshold. 
     (A8) In the example thermal testing system of any of A1-A7, wherein the one or more semiconductor devices comprises at least a first semiconductor device and a second semiconductor device that are attached to a common circuit board; and wherein the thermal testing system comprises: a processing system configured to simultaneously test at least the first semiconductor device and the second semiconductor device while a first subset of the plurality of variable voltage sources controls a first subset of the thermoelectric coolers, which is associated with the first semiconductor device, to have a first cumulative target temperature differential across the first subset of the thermoelectric coolers and a second subset of the plurality of variable voltage sources controls a second subset of the thermoelectric coolers, which is associated with the second semiconductor device, to have a second cumulative target temperature differential across the second subset of the thermoelectric coolers that is different from the first cumulative target temperature differential. 
     (A9) In the example thermal testing system of any of A1-A8, wherein a designated subset of the plurality of variable voltage sources is configured to set a temperature in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located to equal a target temperature by controlling a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device. 
     (A10) In the example thermal testing system of any of A1-A9, wherein the thermal controller is configured to generate a voltage to control a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; and wherein the thermal controller is further configured to not provide the voltage to the circuit board based at least in part on the determination that the fluid pump from which the fluid is received by the one or more first heat exchangers encounters the technical issue. 
     (A11) In the example thermal testing system of any of A1-A10, further comprising: a flow sensor configured to detect a rate of flow of the fluid that is received at the one or more first heat exchangers from the fluid pump; wherein each variable voltage source is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler based at least in part on the rate of flow of the fluid, as detected by the flow sensor, being less than or equal to a flow threshold; and wherein the technical issue includes the rate of flow of the fluid being less than or equal to the flow threshold. 
     (A12) In the example thermal testing system of any of A1-A11, further comprising: a flow sensor configured to detect an amount of the fluid that is stored in the fluid pump; wherein each variable voltage source is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler based at least in part on the amount of the fluid that is stored in the fluid pump, as detected by the flow sensor, being less than or equal to an amount threshold; and wherein the technical issue includes the amount of the fluid that is stored in the fluid pump being less than or equal to the amount threshold. 
     (A13) In the example thermal testing system of any of A1-A12, further comprising: a temperature sensor configured to detect a temperature of the fluid that is received at the one or more first heat exchangers from the fluid pump; wherein each variable voltage source is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler based at least in part on the temperature of the fluid, as detected by the temperature sensor, being greater than or equal to a temperature threshold; and wherein the technical issue includes the temperature of the fluid being greater than or equal to the temperature threshold. 
     (A14) In the example thermal testing system of any of A1-A13, further comprising: a pressure sensor configured to detect a pressure between a designated second heat exchanger of the one or more second heat exchangers and a designated semiconductor device of the one or more semiconductor devices; wherein each variable voltage source that is configured to control a thermoelectric cooler in the subset of the plurality of thermoelectric coolers that is positioned between a designated first heat exchanger of the one or more first heat exchangers and the designated second heat exchanger is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler based at least in part on the pressure between the designated second heat exchanger and the designated semiconductor device, as detected by the pressure sensor, being less than or equal to a pressure threshold. 
     (A15) In the example thermal testing system of any of A1-A14, further comprising: a pressure sensor configured to detect a pressure between a designated second heat exchanger of the one or more second heat exchangers and a designated semiconductor device of the one or more semiconductor devices, which is attached to a circuit board; wherein the thermal controller is configured to conditionally provide power to the circuit board, the thermal controller configured to not provide the power to the circuit board based at least in part on the pressure between the designated second heat exchanger and the designated semiconductor device, as detected by the pressure sensor, being less than or equal to a pressure threshold. 
     (A16) In the example thermal testing system of any of A1-A15, wherein a subset of the plurality of variable voltage sources is configured to modify a temperature of a designated semiconductor device, which is attached to a circuit board and which is included among the one or more semiconductor devices, to equal a target temperature by generating one or more input voltages to control a subset of the thermoelectric coolers that corresponds to the designated semiconductor device without modifying temperatures of other respective semiconductor devices that are attached to the circuit board. 
     (A17) In the example thermal testing system of any of A1-A16, further comprising: a temperature sensor configured to detect a temperature of a designated second heat exchanger that is included among the one or more second heat exchangers; wherein each variable voltage source that corresponds to a thermoelectric cooler in a subset of the thermoelectric coolers that corresponds to the designated second heat exchanger is configured to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on the temperature of the designated second heat exchanger, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (B1) An example thermal testing system ( FIG.  1 ,  100   ;  FIG.  2 ,  200   ;  FIG.  3 ,  300   ;  FIG.  4 ,  400   ) comprises a plurality of thermoelectric coolers ( FIG.  1 ,  114 ,  124   ;  FIG.  2 ,  214     a - 214   b ,  224   a - 224   b ,  234   a - 234   b ;  FIG.  3 ,  314     a - 314   b ;  FIG.  4 ,  414     a - 414   b ), a thermal controller ( FIG.  1 ,  102   ;  FIG.  2 ,  202   ;  FIG.  3 ,  302   ;  FIG.  4 ,  402   ), one or more first heat exchangers ( FIG.  1 ,  112 ,  122   ;  FIG.  2 ,  212 ,  222 ,  232   ;  FIG.  3 ,  312   ;  FIG.  4 ,  412   ), one or more second heat exchangers ( FIG.  1 ,  116 ,  126   ;  FIG.  2 ,  216 ,  226 ,  236   ;  FIG.  3 ,  316   ;  FIG.  4 ,  416   ), and a processing system ( FIG.  2 ,  250   ;  FIG.  4 ,  450   ). Each thermoelectric cooler has first and second opposing surfaces. Each thermoelectric cooler is configured to have a temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler, which is caused by a Peltier effect, based on a respective input voltage ( FIG.  1 ,  110 ,  120   ;  FIG.  3 ,  310 ,  320   ;  FIG.  4 ,  410 ,  420   ). Each subset of a plurality of subsets of the thermoelectric coolers is positioned between a respective first heat exchanger of the one or more first heat exchangers and a respective second heat exchanger of the one or more second heat exchangers. Each subset includes at least one of the plurality of thermoelectric coolers. The thermal controller comprises a plurality of variable voltage sources ( FIG.  1 ,  130   ,  FIG.  2 ,  230   ;  FIG.  3 ,  330   ,  FIG.  4 ,  430   ) that are configured to control the plurality of respective thermoelectric coolers independently. Each variable voltage source is configured to generate a respective input voltage that corresponds to a respective target temperature differential such that the respective input voltage causes a respective thermoelectric cooler of the plurality of thermoelectric coolers to have the respective target temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler. Each first heat exchanger is configured to transfer heat between a respective subset of the thermoelectric coolers and a fluid ( FIG.  1 ,  152   ;  FIG.  3 ,  352   ;  FIG.  4 ,  452   ). Each second heat exchanger is configured to transfer heat between a respective semiconductor device of a one or more semiconductor devices ( FIG.  1 ,  118 ,  128   ;  FIG.  2 ,  218 ,  228 ,  238   ;  FIG.  3 ,  318   ;  FIG.  4 ,  418   ) and a respective subset of the thermoelectric coolers. The processing system is configured to identify a target temperature of a designated semiconductor device of the one or more semiconductor devices by reviewing a temperature indicator that indicates the target temperature, which is manually set by a user of the thermal testing system or which is programmatically set by software. The processing system is further configured to determine whether a human or programmatic error occurs with regard to setting of the target temperature based at least in part on whether an absolute value of the target temperature is greater than or equal to a first temperature threshold. The processing system is further configured to cause each variable voltage source of the plurality of variable voltage sources to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on a determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. 
     (B2) In the example thermal testing system of B1, further comprising: a temperature sensor configured to detect a temperature of each second heat exchanger; wherein each variable voltage source is configured to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on the temperature of the second heat exchanger associated with the subset of the thermoelectric coolers that includes the respective thermoelectric cooler, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (B3) In the example thermal testing system of any of B1-B2, further comprising: a temperature sensor configured to detect a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; wherein the thermal controller is configured to conditionally provide power to the circuit board, the thermal controller configured to not provide the power to the circuit board based at least in part on the temperature of the circuit board, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (B4) In the example thermal testing system of any of B1-B3, further comprising: a fluid pump configured to pump the fluid to the one or more first heat exchangers; and a temperature sensor configured to detect a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; wherein the thermal controller is configured to conditionally provide power to the fluid pump, the thermal controller configured to not provide the power to the fluid pump based at least in part on the temperature of the circuit board, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (B5) In the example thermal testing system of any of B1-B4, further comprising: a humidity sensor configured to detect a relative humidity in an environment of a designated semiconductor device of the one or more semiconductor devices; wherein each variable voltage source associated with a designated subset of the thermoelectric coolers, which is associated with the designated semiconductor device, is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected by the humidity sensor, being greater than or equal to a humidity threshold. 
     (B6) In the example thermal testing system of any of B1-B5, wherein each variable voltage source associated with the designated subset of the thermoelectric coolers is configured to automatically resume providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected by the humidity sensor, decreasing below the humidity threshold. 
     (B7) In the example thermal testing system of any of B1-B6, further comprising: a flow sensor configured to detect a rate at which air flows in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located; wherein each variable voltage source associated with a designated subset of the thermoelectric coolers, which is associated with the designated semiconductor device, is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the rate at which air flows in the chamber, as detected by the flow sensor, being greater than or equal to a rate threshold. 
     (B8) In the example thermal testing system of any of B1-B7, wherein the one or more semiconductor devices comprises at least a first semiconductor device and a second semiconductor device that are attached to a common circuit board; and wherein the processing system is further configured to simultaneously test at least the first semiconductor device and the second semiconductor device while a first subset of the plurality of variable voltage sources controls a first subset of the thermoelectric coolers, which is associated with the first semiconductor device, to have a first cumulative target temperature differential across the first subset of the thermoelectric coolers and a second subset of the plurality of variable voltage sources controls a second subset of the thermoelectric coolers, which is associated with the second semiconductor device, to have a second cumulative target temperature differential across the second subset of the thermoelectric coolers that is different from the first cumulative target temperature differential. 
     (B9) In the example thermal testing system of any of B1-B8, wherein a designated subset of the plurality of variable voltage sources is configured to set a temperature in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located to equal a target temperature by controlling a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device. 
     (B10) In the example thermal testing system of any of B1-B9, wherein the thermal controller is configured to generate a voltage to control a circuit board to which the designated semiconductor device is attached; and wherein the thermal controller is further configured to not provide the voltage to the circuit board based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. 
     (B11) In the example thermal testing system of any of B1-B10, wherein the thermal controller is configured to not provide the voltage to the circuit board further based at least in part on the absolute value of the target temperature being greater than or equal to a second temperature threshold that is greater than the first temperature threshold. 
     (B12) In the example thermal testing system of any of B1-B11, wherein the thermal controller is configured to generate a voltage to control a fluid pump from which the fluid is received by the one or more first heat exchangers; and wherein the thermal controller is further configured to not provide the voltage to the fluid pump based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold and further based at least in part on the absolute value of the target temperature being greater than or equal to a third temperature threshold that is greater than the second temperature threshold. 
     (B13) In the example thermal testing system of any of B1-B12, further comprising: an interface configured to generate an indicator, which indicates that the human or programmatic error has occurred with regard to the setting of the target temperature, based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. 
     (B14) In the example thermal testing system of any of B1-B13, wherein the indicator further indicates that the plurality of variable voltage sources is to be reset manually to enable the plurality of variable voltage sources to provide the respective input voltages to the plurality of respective thermoelectric coolers. 
     (B15) In the example thermal testing system of any of B1-B14, wherein the interface is further configured to generate a threshold indicator, which indicates the first temperature threshold, based at least in part on the determination that the human or programmatic error occurs with regard to the setting of the target temperature. 
     (B16) In the example thermal testing system of any of B1-B15, wherein the processing system is further configured to perform a thermal testing process with regard to each of the one or more semiconductor devices while an absolute value of a temperature of the respective semiconductor device is less than the temperature threshold; and wherein the processing system is further configured to discontinue performance of the thermal testing process with regard to each of the one or more semiconductor devices based at least in part on the absolute value of the temperature of the respective semiconductor device being greater than or equal to the temperature threshold. 
     (B17) In the example thermal testing system of any of B1-B16, wherein a subset of the plurality of variable voltage sources is configured to modify a temperature of a designated semiconductor device, which is attached to a circuit board and which is included among the one or more semiconductor devices, to equal a target temperature by generating one or more input voltages to control a subset of the thermoelectric coolers that corresponds to the designated semiconductor device without modifying temperatures of other respective semiconductor devices that are attached to the circuit board. 
     (B18) In the example thermal testing system of any of B1-B17, further comprising: a temperature sensor configured to detect a temperature of a designated second heat exchanger that is included among the one or more second heat exchangers; wherein each variable voltage source that corresponds to a thermoelectric cooler in a subset of the thermoelectric coolers that corresponds to the designated second heat exchanger is configured to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on the temperature of the designated second heat exchanger, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (C1) An example thermal testing system ( FIG.  1 ,  100   ;  FIG.  2 ,  200   ;  FIG.  3 ,  300   ;  FIG.  4 ,  400   ) comprises a plurality of thermoelectric coolers ( FIG.  1 ,  114 ,  124   ;  FIG.  2 ,  214     a - 214   b ,  224   a - 224   b ,  234   a - 234   b ;  FIG.  3 ,  314     a - 314   b ;  FIG.  4 ,  414     a - 414   b ), a thermal controller ( FIG.  1 ,  102   ;  FIG.  2 ,  202   ;  FIG.  3 ,  302   ;  FIG.  4 ,  402   ), one or more first heat exchangers ( FIG.  1 ,  112 ,  122   ;  FIG.  2 ,  212 ,  222 ,  232   ;  FIG.  3 ,  312   ;  FIG.  4 ,  412   ), one or more second heat exchangers ( FIG.  1 ,  116 ,  126   ;  FIG.  2 ,  216 ,  226 ,  236   ;  FIG.  3 ,  316   ;  FIG.  4 ,  416   ), and a current sensor ( FIG.  2 ,  262   ;  FIG.  4 ,  462   ). Each thermoelectric cooler has first and second opposing surfaces. Each thermoelectric cooler is configured to have a temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler, which is caused by a Peltier effect, based on a respective input voltage ( FIG.  1 ,  110 ,  120   ;  FIG.  3 ,  310 ,  320   ;  FIG.  4 ,  410 ,  420   ). Each subset of a plurality of subsets of the thermoelectric coolers is positioned between a respective first heat exchanger of the one or more first heat exchangers and a respective second heat exchanger of the one or more second heat exchangers. Each subset includes at least one of the plurality of thermoelectric coolers. The thermal controller comprises a plurality of variable voltage sources ( FIG.  1 ,  130   ,  FIG.  2 ,  230   ;  FIG.  3 ,  330   ,  FIG.  4 ,  430   ) that are configured to control the plurality of respective thermoelectric coolers independently. Each variable voltage source is configured to generate a respective input voltage that corresponds to a respective target temperature differential such that the respective input voltage causes a respective thermoelectric cooler of the plurality of thermoelectric coolers to have the respective target temperature differential between the first and second opposing surfaces of the respective thermoelectric cooler. Each first heat exchanger is configured to transfer heat between a respective subset of the thermoelectric coolers and a fluid ( FIG.  1 ,  152   ;  FIG.  3 ,  352   ;  FIG.  4 ,  452   ). Each second heat exchanger is configured to transfer heat between a respective semiconductor device of a one or more semiconductor devices ( FIG.  1 ,  118 ,  128   ;  FIG.  2 ,  218 ,  228 ,  238   ;  FIG.  3 ,  318   ;  FIG.  4 ,  418   ) and a respective subset of the thermoelectric coolers. The current sensor is configured to detect a plurality of currents that are provided to the plurality of respective thermoelectric coolers. Each variable voltage source is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler based at least in part on a magnitude of the current that is provided to the respective thermoelectric cooler, as detected by the current sensor, being less than or equal to a current threshold. 
     (C2) In the example thermal testing system of C1, further comprising: a temperature sensor configured to detect a temperature of each second heat exchanger; wherein each variable voltage source is configured to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on the temperature of the second heat exchanger associated with the subset of the thermoelectric coolers that includes the respective thermoelectric cooler, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (C3) In the example thermal testing system of any of C1-C2, further comprising: a temperature sensor configured to detect a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; wherein the thermal controller is configured to conditionally provide power to the circuit board, the thermal controller configured to not provide the power to the circuit board based at least in part on the temperature of the circuit board, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (C4) In the example thermal testing system of any of C1-C3, further comprising: a fluid pump configured to pump the fluid to the one or more first heat exchangers; and a temperature sensor configured to detect a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; wherein the thermal controller is configured to conditionally provide power to the fluid pump, the thermal controller configured to not provide the power to the fluid pump based at least in part on the temperature of the circuit board, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (C5) In the example thermal testing system of any of C1-C4, further comprising: a humidity sensor configured to detect a relative humidity in an environment of a designated semiconductor device of the one or more semiconductor devices; wherein each variable voltage source associated with a designated subset of the thermoelectric coolers, which is associated with the designated semiconductor device, is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected by the humidity sensor, being greater than or equal to a humidity threshold. 
     (C6) In the example thermal testing system of any of C1-C5, wherein each variable voltage source associated with the designated subset of the thermoelectric coolers is configured to automatically resume providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected by the humidity sensor, decreasing below the humidity threshold. 
     (C7) In the example thermal testing system of any of C1-C6, further comprising: a flow sensor configured to detect a rate at which air flows in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located; wherein each variable voltage source associated with a designated subset of the thermoelectric coolers, which is associated with the designated semiconductor device, is configured to discontinue providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the rate at which air flows in the chamber, as detected by the flow sensor, being greater than or equal to a rate threshold. 
     (C8) In the example thermal testing system of any of C1-C7, wherein the one or more semiconductor devices comprises at least a first semiconductor device and a second semiconductor device that are attached to a common circuit board; and wherein the thermal testing system comprises: a processing system configured to simultaneously test at least the first semiconductor device and the second semiconductor device while a first subset of the plurality of variable voltage sources controls a first subset of the thermoelectric coolers, which is associated with the first semiconductor device, to have a first cumulative target temperature differential across the first subset of the thermoelectric coolers and a second subset of the plurality of variable voltage sources controls a second subset of the thermoelectric coolers, which is associated with the second semiconductor device, to have a second cumulative target temperature differential across the second subset of the thermoelectric coolers that is different from the first cumulative target temperature differential. 
     (C9) In the example thermal testing system of any of C1-C8, wherein a designated subset of the plurality of variable voltage sources is configured to set a temperature in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located to equal a target temperature by controlling a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device. 
     (C10) In the example thermal testing system of any of C1-C9, wherein the thermal controller is configured to generate a voltage to control a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; and wherein the thermal controller is further configured to not provide the voltage to the circuit board based at least in part on the magnitude of the current that is provided to the respective thermoelectric cooler, as detected by the current sensor, being less than or equal to the current threshold. 
     (C11) In the example thermal testing system of any of C1-C10, further comprising: an interface configured to generate a first indicator or a second indicator depending on whether at least one current of the plurality of currents is modulated, the interface configured to generate the first indicator based on the at least one current being modulated, the interface configured to generate the second indicator based on the at least one current being unmodulated. 
     (C12) In the example thermal testing system of any of C1-C11, further comprising: an interface configured to generate a plurality of indicators that indicate the respective magnitudes of the plurality of respective currents. 
     (C13) In the example thermal testing system of any of C1-C12, further comprising: an interface configured to generate an alarm regarding each current of the plurality of currents that has a magnitude, as detected by the current sensor, that is less than or equal to the current threshold. 
     (C14) In the example thermal testing system of any of C1-C13, further comprising: an interface configured to generate a plurality of alarms related to a plurality of respective current thresholds, the interface configured to generate each alarm of the plurality of alarms based at least in part on a magnitude of a current of the plurality of currents, as detected by the current sensor, being less than or equal to a respective current threshold of the plurality of current thresholds. 
     (C15) In the example thermal testing system of any of C1-C14, wherein a subset of the plurality of variable voltage sources is configured to modify a temperature of a designated semiconductor device, which is attached to a circuit board and which is included among the one or more semiconductor devices, to equal a target temperature by generating one or more input voltages to control a subset of the thermoelectric coolers that corresponds to the designated semiconductor device without modifying temperatures of other respective semiconductor devices that are attached to the circuit board. 
     (C16) In the example thermal testing system of any of C1-C15, further comprising: a temperature sensor configured to detect a temperature of a designated second heat exchanger that is included among the one or more second heat exchangers; wherein each variable voltage source that corresponds to a thermoelectric cooler in a subset of the thermoelectric coolers that corresponds to the designated second heat exchanger is configured to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on the temperature of the designated second heat exchanger, as detected by the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (D1) An example method of setting one or more temperatures of one or more respective semiconductor devices ( FIG.  1 ,  118 ,  128   ;  FIG.  2 ,  218 ,  228 ,  238   ;  FIG.  3 ,  318   ;  FIG.  4 ,  418   ) in a thermal testing environment comprises controlling ( FIG.  5 ,  502   ) a plurality of thermoelectric coolers ( FIG.  1 ,  114 ,  124   ;  FIG.  2 ,  214     a - 214   b ,  224   a - 224   b ,  234   a - 234   b ;  FIG.  3 ,  314     a - 314   b ;  FIG.  4 ,  414     a - 414   b ) independently using a plurality of respective variable voltage sources ( FIG.  1 ,  130   ;  FIG.  2 ,  230   ;  FIG.  3 ,  330   ;  FIG.  4 ,  430   ). The controlling comprises creating ( FIG.  5 ,  510   ) a plurality of temperature differentials between first and second opposing surfaces of the plurality of respective thermoelectric coolers in accordance with a Peltier effect by applying a plurality of respective input voltages ( FIG.  1 ,  110 ,  120   ;  FIG.  3 ,  310 ,  320   ;  FIG.  4 ,  410 ,  420   ) to the plurality of respective thermoelectric coolers. The method further comprises transferring ( FIG.  5 ,  504   ), using each of one or more first heat exchangers ( FIG.  1 ,  112 ,  122   ;  FIG.  2 ,  212 ,  222 ,  232   ;  FIG.  3 ,  312   ;  FIG.  4 ,  412   ), heat between a fluid ( FIG.  1 ,  152   ;  FIG.  3 ,  352   ;  FIG.  4 ,  452   ) and a respective subset of the thermoelectric coolers that is positioned between the respective first heat exchanger and a respective second heat exchanger of one or more second heat exchangers ( FIG.  1 ,  116 ,  126   ;  FIG.  2 ,  216 ,  226 ,  236   ;  FIG.  3 ,  316   ;  FIG.  4 ,  416   ). Each subset includes at least one of the plurality of thermoelectric coolers. The method further comprises transferring ( FIG.  5 ,  506   ), using each of the one or more second heat exchangers, heat between the a respective semiconductor device of the one or more semiconductor devices and the respective subset of the thermoelectric coolers. The method further comprises discontinuing ( FIG.  5 ,  508   ) the applying of each input voltage to the respective thermoelectric cooler based at least in part on a determination that a fluid pump ( FIG.  1 ,  108   ;  FIG.  3 ,  308   ;  FIG.  4 ,  408   ) from which the fluid is received at the one or more first heat exchangers encounters a technical issue. 
     (D2) In the method of D1, further comprising: detecting, using a temperature sensor, a temperature of a designated second heat exchanger of the one or more second heat exchangers; and delaying, using each variable voltage source in a designated subset of the variable voltage sources that controls a designated subset of the thermoelectric coolers associated with the designated second heat exchanger, providing the respective input voltage to the respective thermoelectric cooler until a manual reset of the respective variable voltage source is performed, based at least in part on the temperature of the designated second heat exchanger, as detected using the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (D3) In the method of any of D1-D2, further comprising: detecting, using a temperature sensor, a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; conditionally providing, using the thermal controller, power to the circuit board, the conditionally providing including not providing the power to the circuit board based at least in part on the temperature of the circuit board, as detected using the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (D4) In the method of any of D1-D3, further comprising: pumping, using the fluid pump, the fluid to the one or more first heat exchangers; detecting, using a temperature sensor, a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; and conditionally providing, using the thermal controller, power to the fluid pump, the conditionally providing including not providing the power to the fluid pump based at least in part on the temperature of the circuit board, as detected using the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (D5) In the method of any of D1-D4, further comprising: detecting, using a humidity sensor, a relative humidity in an environment of a designated semiconductor device of the one or more semiconductor devices; and discontinuing, using each variable voltage source associated with a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected using the humidity sensor, being greater than or equal to a humidity threshold. 
     (D6) In the method of any of D1-D5, further comprising: automatically resuming, using each variable voltage source associated with the designated subset of the thermoelectric coolers, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected using the humidity sensor, decreasing below the humidity threshold. 
     (D7) In the method of any of D1-D6, further comprising: detecting, using a flow sensor, a rate at which air flows in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located; and discontinuing, using each variable voltage source associated with a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the rate at which air flows in the chamber, as detected using the flow sensor, being greater than or equal to a rate threshold. 
     (D8) In the method of any of D1-D7, wherein the one or more semiconductor devices comprise at least a first semiconductor device and a second semiconductor device that are attached to a common circuit board; and wherein the method further comprises: simultaneously testing, using a processing system, at least the first semiconductor device and the second semiconductor device while a first subset of the plurality of variable voltage sources controls a first subset of the thermoelectric coolers, which is associated with the first semiconductor device, to have a first cumulative target temperature differential across the first subset of the thermoelectric coolers and a second subset of the plurality of variable voltage sources controls a second subset of the thermoelectric coolers, which is associated with the second semiconductor device, to have a second cumulative target temperature differential across the second subset of the thermoelectric coolers that is different from the first cumulative target temperature differential. 
     (D9) In the method of any of D1-D8, wherein controlling the plurality of thermoelectric coolers independently comprises: setting, using a designated subset of the plurality of variable voltage sources, a temperature in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located to equal a target temperature by controlling a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device. 
     (D10) In the method of any of D1-D9, further comprising: generating a voltage to control a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; and not providing the voltage to the circuit board based at least in part on the determination that the fluid pump from which the fluid is received at the one or more first heat exchangers encounters the technical issue. 
     (D11) In the method of any of D1-D10, further comprising: detecting a rate of flow of the fluid that is received at the one or more first heat exchangers from the fluid pump; and discontinuing the applying of each input voltage to the respective thermoelectric cooler based at least in part on the rate of flow of the fluid being less than or equal to a flow threshold; wherein the technical issue includes the rate of flow of the fluid being less than or equal to the flow threshold. 
     (D12) In the method of any of D1-D11, further comprising: detecting an amount of the fluid that is stored in the fluid pump; and discontinuing the applying of each input voltage to the respective thermoelectric cooler based at least in part on the amount of the fluid that is stored in the fluid pump being less than or equal to an amount threshold; wherein the technical issue includes the amount of the fluid that is stored in the fluid pump being less than or equal to the amount threshold. 
     (D13) In the method of any of D1-D12, further comprising: detecting a temperature of the fluid that is received at the one or more first heat exchangers from the fluid pump; and discontinuing the applying of each input voltage to the respective thermoelectric cooler based at least in part on the temperature of the fluid being greater than or equal to a temperature threshold; wherein the technical issue includes the temperature of the fluid being greater than or equal to the temperature threshold. 
     (E1) An example method of setting one or more temperatures of one or more respective semiconductor devices ( FIG.  1 ,  118 ,  128   ;  FIG.  2 ,  218 ,  228 ,  238   ;  FIG.  3 ,  318   ;  FIG.  4 ,  418   ) in a thermal testing environment comprises controlling ( FIG.  5 ,  502   ) a plurality of thermoelectric coolers ( FIG.  1 ,  114 ,  124   ;  FIG.  2 ,  214     a - 214   b ,  224   a - 224   b ,  234   a - 234   b ;  FIG.  3 ,  314     a - 314   b ;  FIG.  4 ,  414     a - 414   b ) independently using a plurality of respective variable voltage sources ( FIG.  1 ,  130   ;  FIG.  2 ,  230   ;  FIG.  3 ,  330   ;  FIG.  4 ,  430   ). The controlling comprises creating ( FIG.  5 ,  510   ) a plurality of temperature differentials between first and second opposing surfaces of the plurality of respective thermoelectric coolers in accordance with a Peltier effect by applying a plurality of respective input voltages ( FIG.  1 ,  110 ,  120   ;  FIG.  3 ,  310 ,  320   ;  FIG.  4 ,  410 ,  420   ) to the plurality of respective thermoelectric coolers. The method further comprises transferring ( FIG.  5 ,  504   ), using each of one or more first heat exchangers ( FIG.  1 ,  112 ,  122   ;  FIG.  2 ,  212 ,  222 ,  232   ;  FIG.  3 ,  312   ;  FIG.  4 ,  412   ), heat between a fluid ( FIG.  1 ,  152   ;  FIG.  3 ,  352   ;  FIG.  4 ,  452   ) and a respective subset of the thermoelectric coolers that is positioned between the respective first heat exchanger and a respective second heat exchanger of one or more second heat exchangers ( FIG.  1 ,  116 ,  126   ;  FIG.  2 ,  216 ,  226 ,  236   ;  FIG.  3 ,  316   ;  FIG.  4 ,  416   ). Each subset includes at least one of the plurality of thermoelectric coolers. The method further comprises transferring ( FIG.  5 ,  506   ), using each of the one or more second heat exchangers, heat between the a respective semiconductor device of the one or more semiconductor devices and the respective subset of the thermoelectric coolers. The method further comprises identifying ( FIG.  8 ,  802   ) a target temperature of a designated semiconductor device of the one or more semiconductor devices by reviewing a temperature indicator that indicates the target temperature, which is manually set by a user of the thermal testing system or which is programmatically set by software. The method further comprises determining ( FIG.  8 ,  804   ) whether a human or programmatic error occurs with regard to setting of the target temperature based at least in part on whether an absolute value of the target temperature is greater than or equal to a first temperature threshold. The method further comprises causing ( FIG.  8 ,  806   ) each variable voltage source to not provide the respective input voltage to the respective thermoelectric cooler based at least in part on determining that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. 
     (E2) In the method of E1, further comprising: detecting, using a temperature sensor, a temperature of a designated second heat exchanger of the one or more second heat exchangers; and delaying, using each variable voltage source in a designated subset of the variable voltage sources that controls a designated subset of the thermoelectric coolers associated with the designated second heat exchanger, providing the respective input voltage to the respective thermoelectric cooler until a manual reset of the respective variable voltage source is performed, based at least in part on the temperature of the designated second heat exchanger, as detected using the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (E3) In the method of any of E1-E2, further comprising: detecting, using a temperature sensor, a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; conditionally providing, using the thermal controller, power to the circuit board, the conditionally providing including not providing the power to the circuit board based at least in part on the temperature of the circuit board, as detected using the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (E4) In the method of any of E1-E3, further comprising: pumping, using a fluid pump, the fluid to the one or more first heat exchangers; detecting, using a temperature sensor, a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; and conditionally providing, using the thermal controller, power to the fluid pump, the conditionally providing including not providing the power to the fluid pump based at least in part on the temperature of the circuit board, as detected using the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (E5) In the method of any of E1-E4, further comprising: detecting, using a humidity sensor, a relative humidity in an environment of a designated semiconductor device of the one or more semiconductor devices; and discontinuing, using each variable voltage source associated with a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected using the humidity sensor, being greater than or equal to a humidity threshold. 
     (E6) In the method of any of E1-E5, further comprising: automatically resuming, using each variable voltage source associated with the designated subset of the thermoelectric coolers, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected using the humidity sensor, decreasing below the humidity threshold. 
     (E7) In the method of any of E1-E6, further comprising: detecting, using a flow sensor, a rate at which air flows in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located; and discontinuing, using each variable voltage source associated with a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the rate at which air flows in the chamber, as detected using the flow sensor, being greater than or equal to a rate threshold. 
     (E8) In the method of any of E1-E7, wherein the one or more semiconductor devices comprise at least a first semiconductor device and a second semiconductor device that are attached to a common circuit board; and wherein the method further comprises: simultaneously testing, using a processing system, at least the first semiconductor device and the second semiconductor device while a first subset of the plurality of variable voltage sources controls a first subset of the thermoelectric coolers, which is associated with the first semiconductor device, to have a first cumulative target temperature differential across the first subset of the thermoelectric coolers and a second subset of the plurality of variable voltage sources controls a second subset of the thermoelectric coolers, which is associated with the second semiconductor device, to have a second cumulative target temperature differential across the second subset of the thermoelectric coolers that is different from the first cumulative target temperature differential. 
     (E9) In the method of any of E1-E8, wherein controlling the plurality of thermoelectric coolers independently comprises: setting, using a designated subset of the plurality of variable voltage sources, a temperature in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located to equal a target temperature by controlling a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device. 
     (E10) In the method of any of E1-E9, further comprising: generating a first voltage to control a circuit board to which the designated semiconductor device is attached; and not providing the first voltage to the circuit board based at least in part on determining that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold. 
     (E11) In the method of any of E1-E10, wherein not providing the first voltage to the circuit board comprises: not providing the first voltage to the circuit board further based at least in part on the absolute value of the target temperature being greater than or equal to a second temperature threshold that is greater than the first temperature threshold. 
     (E12) In the method of any of E1-E11, further comprising: generating a second voltage to control a fluid pump from which the fluid is received at the one or more first heat exchangers; and not providing the second voltage to the fluid pump based at least in part on determining that the human or programmatic error occurs with regard to the setting of the target temperature as a result of the absolute value of the target temperature being greater than or equal to the first temperature threshold and further based at least in part on the absolute value of the target temperature being greater than or equal to a third temperature threshold that is greater than the second temperature threshold. 
     (E13) In the method of any of E1-E12, further comprising: generating an indicator, which indicates that the human or programmatic error has occurred with regard to the setting of the target temperature, based at least in part on determining that the human or programmatic error occurs with regard to the setting of the target temperature. 
     (E14) In the method of any of E1-E13, wherein generating the indicator comprises: generating the indicator, which further indicates that the plurality of variable voltage sources is to be reset manually to enable the plurality of variable voltage sources to provide the respective input voltages to the plurality of respective thermoelectric coolers. 
     (E15) In the method of any of E1-E14, further comprising: generating a threshold indicator, which indicates the first temperature threshold, based at least in part on determining that the human or programmatic error occurs with regard to the setting of the target temperature. 
     (E16) In the method of any of E1-E15, further comprising: performing a thermal testing process with regard to each of the one or more semiconductor devices while an absolute value of a temperature of the respective semiconductor device is less than the temperature threshold; and discontinuing the performing of the thermal testing process with regard to each of the one or more semiconductor devices based at least in part on the absolute value of the temperature of the respective semiconductor device being greater than or equal to the temperature threshold. 
     (F1) An example method of setting one or more temperatures of one or more respective semiconductor devices ( FIG.  1 ,  118 ,  128   ;  FIG.  2 ,  218 ,  228 ,  238   ;  FIG.  3 ,  318   ;  FIG.  4 ,  418   ) in a thermal testing environment comprises controlling ( FIG.  5 ,  502   ) a plurality of thermoelectric coolers ( FIG.  1 ,  114 ,  124   ;  FIG.  2 ,  214     a - 214   b ,  224   a - 224   b ,  234   a - 234   b ;  FIG.  3 ,  314     a - 314   b ;  FIG.  4 ,  414     a - 414   b ) independently using a plurality of respective variable voltage sources ( FIG.  1 ,  130   ;  FIG.  2 ,  230   ;  FIG.  3 ,  330   ;  FIG.  4 ,  430   ). The controlling comprises creating ( FIG.  5 ,  510   ) a plurality of temperature differentials between first and second opposing surfaces of the plurality of respective thermoelectric coolers in accordance with a Peltier effect by applying a plurality of respective input voltages ( FIG.  1 ,  110 ,  120   ;  FIG.  3 ,  310 ,  320   ;  FIG.  4 ,  410 ,  420   ) to the plurality of respective thermoelectric coolers. The method further comprises transferring ( FIG.  5 ,  504   ), using each of one or more first heat exchangers ( FIG.  1 ,  112 ,  122   ;  FIG.  2 ,  212 ,  222 ,  232   ;  FIG.  3 ,  312   ;  FIG.  4 ,  412   ), heat between a fluid ( FIG.  1 ,  152   ;  FIG.  3 ,  352   ;  FIG.  4 ,  452   ) and a respective subset of the thermoelectric coolers that is positioned between the respective first heat exchanger and a respective second heat exchanger of one or more second heat exchangers ( FIG.  1 ,  116 ,  126   ;  FIG.  2 ,  216 ,  226 ,  236   ;  FIG.  3 ,  316   ;  FIG.  4 ,  416   ). Each subset includes at least one of the plurality of thermoelectric coolers. The method further comprises transferring ( FIG.  5 ,  506   ), using each of the one or more second heat exchangers, heat between the a respective semiconductor device of the one or more semiconductor devices and the respective subset of the thermoelectric coolers. The method further comprises detecting ( FIG.  9 ,  902   ) a plurality of currents that are provided to the plurality of respective thermoelectric coolers. The method further comprises discontinuing ( FIG.  9 ,  904   ) the applying of a designated input voltage of the plurality of input voltages to the respective thermoelectric cooler based at least in part on a magnitude of the current that is provided to the respective thermoelectric cooler being less than or equal to a current threshold. 
     (F2) In the method of F1, further comprising: detecting, using a temperature sensor, a temperature of a designated second heat exchanger of the one or more second heat exchangers; and delaying, using each variable voltage source in a designated subset of the variable voltage sources that controls a designated subset of the thermoelectric coolers associated with the designated second heat exchanger, providing the respective input voltage to the respective thermoelectric cooler until a manual reset of the respective variable voltage source is performed, based at least in part on the temperature of the designated second heat exchanger, as detected using the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (F3) In the method of any of F1-F2, further comprising: detecting, using a temperature sensor, a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; conditionally providing, using the thermal controller, power to the circuit board, the conditionally providing including not providing the power to the circuit board based at least in part on the temperature of the circuit board, as detected using the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (F4) In the method of any of F1-F3, further comprising: pumping, using a fluid pump, the fluid to the one or more first heat exchangers; detecting, using a temperature sensor, a temperature of a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; and conditionally providing, using the thermal controller, power to the fluid pump, the conditionally providing including not providing the power to the fluid pump based at least in part on the temperature of the circuit board, as detected using the temperature sensor, having an absolute value that is greater than or equal to a temperature threshold. 
     (F5) In the method of any of F1-F4, further comprising: detecting, using a humidity sensor, a relative humidity in an environment of a designated semiconductor device of the one or more semiconductor devices; and discontinuing, using each variable voltage source associated with a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected using the humidity sensor, being greater than or equal to a humidity threshold. 
     (F6) In the method of any of F1-F5, further comprising: automatically resuming, using each variable voltage source associated with the designated subset of the thermoelectric coolers, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the relative humidity, as detected using the humidity sensor, decreasing below the humidity threshold. 
     (F7) In the method of any of F1-F6, further comprising: detecting, using a flow sensor, a rate at which air flows in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located; and discontinuing, using each variable voltage source associated with a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device, providing the respective input voltage to the respective thermoelectric cooler in the designated subset based at least in part on the rate at which air flows in the chamber, as detected using the flow sensor, being greater than or equal to a rate threshold. 
     (F8) In the method of any of F1-F7, wherein the one or more semiconductor devices comprise at least a first semiconductor device and a second semiconductor device that are attached to a common circuit board; and wherein the method further comprises: simultaneously testing, using a processing system, at least the first semiconductor device and the second semiconductor device while a first subset of the plurality of variable voltage sources controls a first subset of the thermoelectric coolers, which is associated with the first semiconductor device, to have a first cumulative target temperature differential across the first subset of the thermoelectric coolers and a second subset of the plurality of variable voltage sources controls a second subset of the thermoelectric coolers, which is associated with the second semiconductor device, to have a second cumulative target temperature differential across the second subset of the thermoelectric coolers that is different from the first cumulative target temperature differential. 
     (F9) In the method of any of F1-F8, wherein controlling the plurality of thermoelectric coolers independently comprises: setting, using a designated subset of the plurality of variable voltage sources, a temperature in a chamber in which a designated semiconductor device of the one or more semiconductor devices is located to equal a target temperature by controlling a designated subset of the thermoelectric coolers that is associated with the designated semiconductor device. 
     (F10) In the method of any of F1-F9, further comprising: generating a voltage to control a circuit board to which a designated semiconductor device of the one or more semiconductor devices is attached; and not providing the voltage to the circuit board based at least in part on the magnitude of the current that is provided to the respective thermoelectric cooler being less than or equal to the current threshold. 
     (F11) In the method of any of F1-F10, further comprising: generating a first indicator or a second indicator depending on whether at least one current of the plurality of currents is modulated, including: generating the first indicator based on the at least one current being modulated, or generating the second indicator based on the at least one current being unmodulated. 
     (F12) In the method of any of F1-F11, further comprising: generating a plurality of indicators that indicate the respective magnitudes of the plurality of respective currents. 
     (F13) In the method of any of F1-F12, further comprising: generating an alarm regarding each current of the plurality of currents that has a magnitude that is less than or equal to the current threshold. 
     (F14) In the method of any of F1-F13, further comprising: selecting an alarm from a plurality of alarms that correspond to a plurality of respective magnitude ranges based at least in part on the magnitude of the current that is provided to the thermoelectric cooler to which application of the designated input voltage is discontinued being included in the magnitude range to which the selected alarm corresponds; and generating the alarm. 
     IV. Example Computer System 
       FIG.  10    depicts an example computer  1000  in which embodiments may be implemented. The processing system  250  shown in  FIG.  2    and/or the processing system  450  shown in  FIG.  4    may be implemented using computer  1000 , including one or more features of computer  1000  and/or alternative features. Computer  1000  may be a general-purpose computing device in the form of a conventional personal computer, a mobile computer, or a workstation, for example, or computer  1000  may be a special purpose computing device. The description of computer  1000  provided herein is provided for purposes of illustration, and is not intended to be limiting. Embodiments may be implemented in further types of computer systems, as would be known to persons skilled in the relevant art(s). 
     As shown in  FIG.  10   , computer  1000  includes a processing unit  1002 , a system memory  1004 , and a bus  1006  that couples various system components including system memory  1004  to processing unit  1002 . Bus  1006  represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. System memory  1004  includes read only memory (ROM)  1008  and random access memory (RAM)  1010 . A basic input/output system  1012  (BIOS) is stored in ROM  1008 . 
     Computer  1000  also has one or more of the following drives: a hard disk drive  1014  for reading from and writing to a hard disk, a magnetic disk drive  1016  for reading from or writing to a removable magnetic disk  1018 , and an optical disk drive  1020  for reading from or writing to a removable optical disk  1022  such as a CD ROM, DVD ROM, or other optical media. Hard disk drive  1014 , magnetic disk drive  1016 , and optical disk drive  1020  are connected to bus  1006  by a hard disk drive interface  1024 , a magnetic disk drive interface  1026 , and an optical drive interface  1028 , respectively. The drives and their associated computer-readable storage media provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for the computer. Although a hard disk, a removable magnetic disk and a removable optical disk are described, other types of computer-readable storage media can be used to store data, such as flash memory cards, digital video disks, random access memories (RAMs), read only memories (ROM), and the like. 
     A number of program modules may be stored on the hard disk, magnetic disk, optical disk, ROM, or RAM. These programs include an operating system  1030 , one or more application programs  1032 , other program modules  1034 , and program data  1036 . Application programs  1032  or program modules  1034  may include, for example, computer program logic for implementing any one or more of (e.g., at least a portion of) the components of each of the thermal testing systems  100 ,  200 ,  300 , and/or  400 , flowchart  500  (including any step of flowchart  500 ), flowchart  600  (including any step of flowchart  600 ), flowchart  700  (including any step of flowchart  700 ), flowchart  800  (including any step of flowchart  800 ), and/or flowchart  900  (including any step of flowchart  900 ), as described herein. 
     A user may enter commands and information into the computer  1000  through input devices such as keyboard  1038  and pointing device  1040 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, touch screen, camera, accelerometer, gyroscope, or the like. These and other input devices are often connected to the processing unit  1002  through a serial port interface  1042  that is coupled to bus  1006 , but may be connected by other interfaces, such as a parallel port, game port, or a universal serial bus (USB). 
     A display device  1044  (e.g., a monitor) is also connected to bus  1006  via an interface, such as a video adapter  1046 . In addition to display device  1044 , computer  1000  may include other peripheral output devices (not shown) such as speakers and printers. 
     Computer  1000  is connected to a network  1048  (e.g., the Internet) through a network interface or adapter  1050 , a modem  1052 , or other means for establishing communications over the network. Modem  1052 , which may be internal or external, is connected to bus  1006  via serial port interface  1042 . 
     As used herein, the terms “computer program medium” and “computer-readable storage medium” are used to generally refer to media (e.g., non-transitory media) such as the hard disk associated with hard disk drive  1014 , removable magnetic disk  1018 , removable optical disk  1022 , as well as other media such as flash memory cards, digital video disks, random access memories (RAMs), read only memories (ROM), and the like. A computer-readable storage medium is not a signal, such as a carrier signal or a propagating signal. For instance, a computer-readable storage medium may not include a signal. Accordingly, a computer-readable storage medium does not constitute a signal per se. Such computer-readable storage media are distinguished from and non-overlapping with communication media (do not include communication media). Communication media embodies computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wireless media such as acoustic, RF, infrared and other wireless media, as well as wired media. Example embodiments are also directed to such communication media. 
     As noted above, computer programs and modules (including application programs  1032  and other program modules  1034 ) may be stored on the hard disk, magnetic disk, optical disk, ROM, or RAM. Such computer programs may also be received via network interface  1050  or serial port interface  1042 . Such computer programs, when executed or loaded by an application, enable computer  1000  to implement features of embodiments discussed herein. Accordingly, such computer programs represent controllers of the computer  1000 . 
     Example embodiments are also directed to computer program products comprising software (e.g., computer-readable instructions) stored on any computer-useable medium. Such software, when executed in one or more data processing devices, causes data processing device(s) to operate as described herein. Embodiments may employ any computer-useable or computer-readable medium, known now or in the future. Examples of computer-readable mediums include, but are not limited to storage devices such as RAM, hard drives, floppy disks, CD ROMs, DVD ROMs, zip disks, tapes, magnetic storage devices, optical storage devices, MEMS-based storage devices, nanotechnology-based storage devices, and the like. 
     It will be recognized that the disclosed technologies are not limited to any particular computer or type of hardware. Certain details of suitable computers and hardware are well known and need not be set forth in detail in this disclosure. 
     V. Conclusion 
     Although the subject matter has been described in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims, and other equivalent features and acts are intended to be within the scope of the claims.