Abstract:
A temperature-controlled fluid forcing system includes a temperature control system generating a stream of flowing temperature-controlled fluid. A heat exchanger includes a thermally conductive housing within which a plurality of walls define a shaped flow space. The stream of temperature-controlled fluid flows through the shaped flow space and is in thermal communication with the housing. A thermally conductive probe is in thermal communication with the exterior of the housing of the heat exchanger, the thermally conductive probe comprising a thermally conductive protrusion in thermal communication with the exterior of the housing of the heat exchanger, such that, when the thermally conductive probe makes contact with a device under test (DUT), heat is conducted to or from DUT.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to and benefit of U.S. Provisional Patent Application No. 62/305,263, filed Mar. 8, 2016, the contents of which are incorporated herein by reference in their entirety for all purposes. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention generally relates to temperature forcing systems, which provide a stream of fluid at a precisely-controlled temperature and flow rate, and are commonly used in temperature testing of electronic devices, modules and systems, and, in particular, to a temperature forcing system which uses heat flow by conduction instead of convection to apply temperature control of a device under test (DUT) with increased efficiency and spatial precision. 
         [0004]    2. Discussion of Related Art 
         [0005]    A temperature forcing system is a device which produces a stream of flowing fluid, such as air, nitrogen or other inert gas, at a precisely-controlled temperature and flow rate. Such systems are commonly used in temperature testing of electronic devices, modules and systems. In this application, a stream of temperature-controlled fluid is directed onto the device under test (DUT) to affect the temperature of the DUT. The DUT is then run through a series of performance tests to determine whether the performance of the DUT at various temperatures is acceptable. 
         [0006]    These temperature stream testing systems use convection heat transfer to control temperature of the DUT. Oftentimes, it can be desirable to direct the temperature altering mechanism, i.e., stream, precisely, such that only the portion of the DUT actually being tested is affected by the temperature stream. This can result in a reduction in lost temperature control fluid, and, therefore, a more efficient testing system and process. 
       SUMMARY 
       [0007]    According to one aspect, a temperature-controlled fluid forcing system is provided. The system includes a temperature control system for cooling and/or heating a fluid and generating a stream of flowing temperature-controlled fluid. A conduit directs the stream of flowing temperature-controlled fluid through a first outlet. A heat exchanger receives the stream of temperature-controlled fluid from the first outlet. The heat exchanger comprises: (i) a thermally conductive housing having an interior and an exterior, (ii) an inlet at which the stream of temperature-controlled fluid is received, such that the stream of temperature-controlled fluid is directed into the interior of the housing, (iii) a plurality of walls within the interior of the housing, the plurality of walls defining a shaped flow space within the interior of the housing, the inlet being in communication with the shaped flow space such that the stream of temperature-controlled fluid flows through the shaped flow space and is in thermal communication with the housing, and (iv) a second outlet in communication with the shaped flow space such that the stream of temperature-controlled fluid is exhausted from the interior of the housing through the second outlet after flowing through the shaped flow space;. A thermally conductive probe is disposed in thermal communication with the exterior of the housing of the heat exchanger, the thermally conductive probe comprising a thermally conductive protrusion in thermal communication with the exterior of the housing of the heat exchanger, such that, when the thermally conductive probe makes contact with a device under test (DUT), heat is conducted to or from DUT. 
         [0008]    In some exemplary embodiments, when the thermally conductive probe makes contact with the device under test (DUT), temperature of the DUT is controllable. 
         [0009]    In some exemplary embodiments, the system further comprises a temperature sensing device for sensing temperature of the thermally conductive probe, the temperature of the thermally conductive probe being used to control temperature of the DUT. 
         [0010]    In some exemplary embodiments, the system further comprises a temperature sensing device for sensing temperature of the DUT, such that temperature of the DUT is controllable. 
         [0011]    In some exemplary embodiments, the shaped flow space in the interior of the housing of the heat exchanger comprises a serpentine shape. 
         [0012]    In some exemplary embodiments, the housing of the heat exchanger comprises a thermally conductive material. The thermally conductive material can comprise metal. The thermally conductive material can comprise aluminum. The thermally conductive material can comprise copper. 
         [0013]    In some exemplary embodiments, the thermally conductive probe comprises a thermally conductive material. The thermally conductive material can comprise metal. The thermally conductive material can comprise aluminum. The thermally conductive material can comprise copper. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The foregoing and other objects, features and advantages will be apparent from the following, more particular description of the embodiments, as illustrated in the accompanying figures, wherein like reference characters generally refer to identical or structurally and/or functionally similar parts throughout the different views. The figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the embodiments. 
           [0015]      FIG. 1  includes a schematic perspective view of a temperature-controlled fluid processing system, for example, a temperature forcing system, e.g., air forcing system, to which the present disclosure is applicable. 
           [0016]      FIG. 2  includes a schematic perspective view of another embodiment of a temperature-controlled fluid processing system, for example, a temperature forcing system, e.g., an air forcing system, to which the present disclosure is applicable. 
           [0017]      FIG. 3  includes a detailed schematic diagram of a portion of temperature forcing system of  FIG. 1 , according to another exemplary embodiment. 
           [0018]      FIG. 4  includes a schematic diagram of a temperature forcing system, using a conductive temperature probe for controlling temperature of a DUT, according to exemplary embodiments. 
           [0019]      FIG. 5  includes a schematic diagram of another temperature forcing system, using a conductive temperature probe for controlling temperature of a DUT, according to exemplary embodiments. 
           [0020]      FIG. 6  includes a schematic perspective view of a heat exchanger used in a temperature forcing system, according to some exemplary embodiments. 
           [0021]      FIG. 7  includes a schematic cross-sectional view of the heat exchanger of  FIG. 6 , taken along line  7 - 7  of  FIG. 6 , according to exemplary embodiments. 
           [0022]      FIG. 8  includes a schematic cross-sectional view of the heat exchanger of  FIG. 6 , taken along line  8 - 8  of  FIG. 7 , according to exemplary embodiments. 
           [0023]      FIG. 9A  includes a schematic perspective view of a contact probe, according to exemplary embodiments. 
           [0024]      FIG. 9B  includes a bottom view of the contact probe of  FIG. 9A , illustrating the configuration of a contact protrusion portion of the contact probe, according to some exemplary embodiments. 
           [0025]      FIG. 10A  includes a schematic perspective view of another contact probe, according to exemplary embodiments. 
           [0026]      FIG. 10B  includes a bottom view of the contact probe of  FIG. 10A , illustrating the configuration of a contact protrusion portion of the contact probe, according to some exemplary embodiments. 
           [0027]      FIG. 11A  includes a schematic perspective view of another contact probe, according to exemplary embodiments. 
           [0028]      FIG. 11B  includes a bottom view of the contact probe of  FIG. 11A , illustrating the configuration of a contact protrusion portion of the contact probe, according to some exemplary embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    In the description that follows, features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments. Description will now be made in detail of exemplary embodiments, one or more of which are illustrated in the drawings. Each embodiment is provided to illustrate the invention, and is not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used in another embodiment to yield a further embodiment. It is intended that the present description include such modifications and variations as come within the scope and spirit of the invention. 
         [0030]      FIG. 1  includes a schematic perspective view of a temperature-controlled fluid processing system, for example, a temperature forcing system, e.g., air forcing system  10 , to which the present disclosure is applicable.  FIG. 2  includes a schematic perspective view of another embodiment of a temperature-controlled fluid processing system, for example, a temperature forcing system, e.g., air forcing system  100 , to which the present disclosure is applicable. Temperature forcing systems  10 ,  100  to which the present disclosure is directed can be used to produce a fluid such as air, nitrogen, or other inert gas with a precisely controlled temperature and flow rate, and can direct a stream of that fluid into a particular region, such as, for example, onto a device under test (DUT)  19 ,  119 , to control the temperature of the DUT  19 ,  119 . DUT  19 ,  119  can be an integrated circuit (IC), which can be contained within its IC package. Alternatively, DUT  19 ,  119  can be a semiconductor wafer with multiple IC dies integrated therein, or it can be a printed circuit board (PCB) with multiple ICs installed thereon. According to some exemplary embodiments, the temperature-controlled forcing system  10 ,  100  may comprise a THERMOSTREAM® Air Forcing System, as manufactured and sold by inTEST Thermal Solutions Corporation of Mansfield, Mass., or other similar system. 
         [0031]    Temperature forcing systems  10 ,  100  may include a chiller/controller unit  12 ,  112 , which includes a refrigeration system for generating a stream of dry, cold gas, e.g., air, nitrogen or other fluid. The chilled fluid may be directed into a fluid conveyor, such as a tube and hose system  16 ,  116  which in system  10  directs the air into a head unit  14  and in system  100  directs the air into an insulated “clamshell” box appliance  118 , in which DUT  119  is located, such that temperature of DUT  119  can be controlled. Head unit  14  may include a heater for heating the chilled fluid, such that temperature of the fluid can be precisely controlled. The temperature-controlled fluid may exit head  14  through an outlet  18 . In some exemplary embodiments, a “T-Cap” thermal cap accessory  22  having a shroud  24  is commonly attached at outlet  18 . Shroud  24  can be used to at least partially enclose or cover DUT  19  to provide a contained temperature-controlled environment in which temperature of DUT  19  is controlled. In system  100  of  FIG. 2 , clamshell appliance  118  provides a contained temperature-controlled environment in which temperature of DUT  19  is controlled. 
         [0032]      FIG. 3  includes a detailed schematic diagram of a portion of temperature forcing system  10  of  FIG. 1 , according to another exemplary embodiment. In this embodiment, head unit  14  is connected by claims  15  at outlet  18  to a ring  17 , which mounts over and at least partially encloses DUT  19 . In this exemplary illustration, DUT  19  is illustrated as a PCB with multiple electronic devices mounted thereon. 
         [0033]    Thus, according to temperature forcing systems  10 ,  100  illustrated in  FIGS. 1-3 , as described above, temperature control is achieved by convection via the flow of the temperature-controlled fluid onto or in close proximity to DUT  19 ,  119 . According to exemplary embodiments, temperature forcing systems  10 ,  100  can be modified such that heat transfer by conduction is used to force DUTs  19 ,  119  to a desired test temperature. To achieve this conversion from heat transfer by convection to heat transfer by conduction, according to exemplary embodiments, the output fluid flow from temperature forcing systems  10 ,  100  is forced into a high-efficiency heat exchanger, which can be positioned in contact with DUT  19 ,  119 . The heat exchanger is maintained in contact with DUT  19 ,  119  such that the heat transfer is accomplished using a thermal conduction path. One benefit of conductive temperature control of DUT  19 ,  119  over convective temperature control is that, with the conductive temperature control of the present disclosure, only the device to be tested, i.e., DUT  19 ,  119 , is affected thermally. Other elements, such as, for example, adjacent components and/or the load board itself, can remain thermally isolated while temperature of DUT  19 ,  119  is affected. This results in substantially reduced loss or waste of temperature control fluid, which in turn produces a more efficient test system and process. 
         [0034]      FIG. 4  includes a schematic diagram of a temperature forcing system  200 , using a conductive temperature probe for controlling temperature of a DUT, according to exemplary embodiments. Referring to  FIG. 4 , a portion of system  200  is illustrated to facilitate detailed description. The remainder of system  200  not shown in the figure is the same as that portion of system  10  illustrated in  FIG. 1 . System  200  includes head unit  214 , analogous to head unit  14  of system  10 . An outlet pipe structure  218  is coupled to the output of head unit  214  to capture and carry the temperature-controlled fluid output by system  200  for temperature control. Outlet pipe structure  218  transports the temperature-controlled fluid into an inlet  230  of high-efficiency heat exchanger  222 , which circulates the fluid internally and outputs the fluid at outlet  232 , which is connected to exhaust pipe  220 . The temperature-controlled fluid circulating in the interior of heat exchanger  222  transfers heat to/from the thermally conductive body of heat exchanger  222 , which contacts an optional thermally conductive thermocouple mounting plate  224 . Thermocouple mounting plate  224  can be used as a means for mounting and connecting a thermocouple in proximity to or in contact with heat exchanger  222  to monitor its temperature, if desired. This can provide an optional temperature parameter input, which can be used, if desired, in the temperature control function of system  200 . 
         [0035]    When present, thermally conductive thermocouple mounting plate  224  is thermally connected to a thermally conductive DUT contact probe  228 , which is mounted on the bottom surface of thermally conductive thermocouple mounting plate  224 . If thermally conductive thermocouple mounting plate  224  is not present, then thermally conductive DUT contact probe  228  is mounted to the bottom surface of heat exchanger  222 . In either configuration, heat transfer to/from DUT  19 ,  119  is effected conductively by contact of a contact protrusion portion  227  of thermally conductive DUT contact probe  228  with DUT  19 ,  119 . It is noted that, in some exemplary embodiments, heat exchanger  222 , thermocouple mounting plate  224 , and DUT contact probe  228  can be held together by one or more pins  233  through mounting holes  248  in mounting bosses  235  (see  FIGS. 6-8 ). Other means of attachment can be used, such as screws, nuts and bolts, etc. 
         [0036]      FIG. 5  includes a schematic diagram of a temperature forcing system  200 A, using a conductive temperature probe for controlling temperature of a DUT, according to exemplary embodiments. Referring to  FIG. 5 , a portion of system  200 A is illustrated to facilitate detailed description. The remainder of system  200 A not shown in the figure is the same as that portion of system  10  illustrated in  FIG. 1 . System  200 A of  FIG. 5  is similar to system  200  of  FIG. 4 , except that  FIG. 5  illustrates system  200 A making use of one or more thermocouples to monitor one or more respective temperature parameters which optionally can be used in the temperature control implemented by system  200 A. Referring to  FIG. 5 , system  200 A includes head unit  214 , analogous to head unit  14  of system  10 . Outlet pipe structure  218  is coupled to the output of head unit  214  to capture and carry the temperature-controlled fluid output by system  200  for temperature control. Outlet pipe structure  218  transports the temperature-controlled fluid into an inlet  230  of high-efficiency heat exchanger  222 , which circulates the fluid internally and outputs the fluid at outlet  232 , which is connected to exhaust pipe  220 . The temperature-controlled fluid circulating in the interior of heat exchanger  222  transfers heat to/from the thermally conductive body of heat exchanger  222 , which contacts an optional thermally conductive thermocouple mounting plate  224 . Thermocouple mounting plate  224  can be used as a means for mounting and connecting a thermocouple (not shown) in proximity to or in contact with heat exchanger  222  to monitor its temperature, if desired. An optional second thermocouple  254  can be mounted to and monitor temperature of a portion  258  of system  200 A in proximity to DUT  19 ,  119 . The thermocouples are wired via wires  256  and  252 , via head  214 , to system controller in chiller/controller unit  12 ,  112 . This can provide one or more optional temperature parameter inputs, which can be used, if desired, in the temperature control function of system  200 A. 
         [0037]    When present, thermally conductive thermocouple mounting plate  224  is thermally connected to a thermally conductive DUT contact probe  228 , which is mounted on the bottom surface of thermally conductive thermocouple mounting plate  224 . If thermally conductive thermocouple mounting plate  224  is not present, then thermally conductive DUT contact probe  228  is mounted to the bottom surface of heat exchanger  222 . In either configuration, heat transfer to/from DUT  19 ,  119  is effected conductively by contact of a contact protrusion portion  227  of thermally conductive DUT contact probe  228  with DUT  19 ,  119 . It is noted that, in some exemplary embodiments, heat exchanger  222 , thermocouple mounting plate  224 , and DUT contact probe  228  can be held together by one or more pins  233  through mounting holes  248  in mounting bosses  235  (see  FIGS. 6-8 ). Other means of attachment can be used, such as screws, nuts and bolts, etc. 
         [0038]      FIG. 6  includes a schematic perspective view of heat exchanger  222 , according to some exemplary embodiments.  FIG. 7  includes a schematic cross-sectional view of heat exchanger  222 , taken along line  7 - 7  of  FIG. 6 , according to some exemplary embodiments.  FIG. 8  includes a schematic cross-sectional view of heat exchanger  222 , taken along line  8 - 8  of  FIG. 7 , according to some exemplary embodiments. Referring to  FIGS. 6-8 , heat exchanger  222  includes a thermally conductive housing portion  240  fixedly attached to a thermally conductive cover portion  242 . Housing portion  240  and cover portion  242  can be made of similar or like thermally conductive materials such as metals, which can be, for example, aluminum, copper, or other thermally conductive material, and can be sealed together by some thermally conductive means, such as welding, brazing, or other process. As noted above, temperature-controlled fluid from head unit  214  of system  200 ,  200 A enters heat exchanger  222  through inlet  230  and circulates through the interior of heat exchanger  222  via a serpentine pattern of void space  246  defined and contained by interior wall structure  247 . The fluid then exits the interior of heat exchanger  222  via outlet  232 . 
         [0039]    Contact probe  228  can have a size and shape of multiple possible sizes and shapes, depending on the particular needs of the particular application. Also, contact protrusion portion  227  of each contact probe  228  can be sized depending on the application, as well as the size constraints of the DUT  19 ,  119 , or region of DUT  19 ,  119  at which temperature effect is to be applied.  FIG. 9A  includes a schematic perspective view of a contact probe  228 A, according to exemplary embodiments.  FIG. 9B  includes a bottom view of contact probe  228 A of  FIG. 9A , illustrating the configuration of contact protrusion portion  227 A of contact probe  228 A, according to some exemplary embodiments.  FIG. 10A  includes a schematic perspective view of a contact probe  228 B, according to exemplary embodiments.  FIG. 10B  includes a bottom view of contact probe  228 B of  FIG. 10A , illustrating the configuration of contact protrusion portion  227 B of contact probe  228 B, according to some exemplary embodiments.  FIG. 11A  includes a schematic perspective view of a contact probe  228 C, according to exemplary embodiments.  FIG. 11B  includes a bottom view of contact probe  228 C of  FIG. 11A , illustrating the configuration of contact protrusion portion  227 C of contact probe  228 C, according to some exemplary embodiments. It will be understood that  FIGS. 9A-11B  are not exhaustive of all of the possible configurations of contact probes  228  and associated contact protrusion portions  227 . Rather, they illustrate that the configurations provide a wide range of variations depending on the particular application. Any number of configurations is possible. 
         [0040]    Referring to  FIGS. 9A, 10A, 11A , contact probes  228 A,  228 B,  228 C include attachment/location pins  229 A,  229 B,  229 C, respectively. These pins mate with holes on the undersides of heat exchanger  222  or thermocouple mounting plate  224  to locate contact probes  228 A,  228 B,  228 C properly and/or to fixedly mount contact probes  228 A,  228 B,  228 C in thermally conductive contact with heat exchanger  222  or thermocouple mounting plate  224 . Contact probe  228  and contact protrusion portions  227  can be made of similar or like thermally conductive materials such as metals, which can be, for example, aluminum, copper, or other thermally conductive material. 
         [0041]    While the present inventive concept has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present inventive concept as defined by the following claims.