Abstract:
A circuit board may include a pump and a channel. The channel may include a liquid metal and a coating. The liquid metal may be pumped through the channel by the pump and the coating reduces diffusion and chemical reaction between the liquid metal and at least portions of the channel. The liquid metal may carry thermal energy to act as a heat transfer mechanism between two or more locations on the substrate. The substrate may include electrical interconnects to allow electrical components to be populated onto the substrate to form an electronics assembly. The pump may be driven by electric current that is utilized by one or more electronic components on the circuit board.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application constitutes a continuation-in-part of United States patent application having the U.S. patent application Ser. No. 12/116,126, entitled SYSTEM AND METHOD FOR A SUBSTRATE WITH INTERNAL PUMPED LIQUID METAL FOR THERMAL SPREADING AND COOLING, naming Nathan P. Lower, Ross K. Wilcoxon, Qizhou Yao, David W. Dlouhy and John A. Chihak as inventors, filed May 6, 2008, which may be currently co-pending, or may be an application of which a currently co-pending application may be entitled to the benefit of the filing date. 
     All subject matter of the Related Applications and of any and all parent, grandparent, great-grandparent, etc. applications of the Related Applications may be incorporated herein by reference to the extent such subject matter may be not inconsistent herewith. 
    
    
     BACKGROUND 
     The present application relates generally to the field of cooling electronics. More specifically, the application relates to cooling of power dissipating devices, such as electronics, using liquid metal. 
     There may be a growing demand to make electronic devices smaller and to operate at higher power. In some applications, including computers, peak power densities may be reaching 400-500 W/cm 2  and climbing. As a result, it may be becoming increasingly more difficult to thermally manage these devices. Increasing temperatures often lead to decreased efficiency and reliability. 
     Conventional thermal management techniques such as forced air cooling, liquid cooling, spray cooling, and thermoelectric cooling may adequately cool the electronic device in some cases, but these techniques may be complicated, unreliable, orientation sensitive, or unsuitable for volume-constrained systems. The use of passive heat spreading materials and heat pipes may also adequately cool the electronic device, but increasing thermal path length, orientation effects and high device power may render these techniques insufficient. Conventional techniques may no longer provide adequate cooling for advanced high power electronic systems. 
     Thus there may be a need for a low cost cooling system for power dissipating systems, such as high power electronic systems. Further, there may be a need for a simple and reliable cooling system that does not add significant cost and power requirements. Further still, there may be a need for an integrated thermal management technique for spreading heat from a circuit board. Yet further, there may be a need for a thermal management system for portable applications, including military applications, which may be smaller in size and weight. 
     SUMMARY 
     One embodiment of the application relates to a circuit board including a device to be cooled and a channel. The liquid metal may be pumped through the channel by an electromagnetic pump mechanism associated with the device to be cooled. 
     Another embodiment of the application relates to a circuit board including an electromagnetic pumping mechanism including one or more electrodes, one or more magnets, and a channel. The channel may include a liquid metal and a coating. The liquid metal may be pumped through the channel by an electromagnetic force generated by the one or more electrodes and one or more magnets. 
     Another embodiment of the application relates to a circuit board including channel means for containing a liquid metal, and pump means for pumping the liquid metal through the channel means. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like elements, in which: 
         FIG. 1  illustrates an overhead schematic view of a circuit board with an integrated thermal management system. 
         FIG. 2  illustrates a thermal imaging schematic view of a thermal management system similar to that of  FIG. 1 . 
         FIG. 3  illustrates a perspective view of an electromagnetic pump for pumping liquid metal in the thermal management system of  FIG. 1 . 
         FIG. 4  illustrates a thermal imaging schematic view of thermal management system of  FIG. 1 . 
         FIG. 5  illustrates a thermal imaging schematic view of a thermal management system including a copper insert. 
         FIG. 6  illustrates a side cross section view through a portion of the thermal management system of  FIG. 1 . 
         FIG. 7  illustrates side cross section view through another portion of the thermal management system of  FIG. 1 . 
         FIG. 8  illustrates a side view of a circuit board with an integrated thermal management system. 
         FIG. 9  illustrates an overhead view of a circuit board with an integrated thermal management system. 
         FIG. 10  illustrates a high-level operational flow diagram. 
         FIG. 11  illustrates a high-level operational flow diagram. 
     
    
    
     DETAILED DESCRIPTION 
     Before describing in detail the particular improved system and method, it should be observed that the invention may include, but may be not limited to a novel structural combination of conventional data/signal processing components and communications circuits, and not in the particular detailed configurations thereof. Accordingly, the structure, methods, functions, control and arrangement of conventional components software, and circuits have, for the most part, been illustrated in the drawings by readily understandable block representations and schematic diagrams, in order not to obscure the disclosure with structural details which will be readily apparent to those skilled in the art, having the benefit of the description herein. Further, the invention may be not limited to the particular embodiments depicted in the exemplary diagrams, but should be construed in accordance with the language in the claims. 
     Referring to  FIGS. 1 and 2 , according to an exemplary embodiment, a thermal management system  10 A may provide significant improvement in the thermal spreading capability of a substrate  12  including circuitry  13  as compared to passive materials and composites. The thermal management system  10 A may include a closed-loop liquid metal channel  14  in substrate  12  containing a device  16  to be cooled by liquid metal  20  flowing in the liquid metal channel  14 . According to various exemplary embodiments, the substrate  12  may be a printed circuit board, a thermal spreader (which may be rigid or mechanically flexible), or any other substrate to which at least one power dissipating device, such as an electronic component, may be attached or interfaced. According to various exemplary embodiments, the device  16  may be a high power electronic circuit (e.g., a rectifier, an inverter, another power semiconductor device, etc.), a microprocessor, and/or any other analog or digital circuit that generates heat. 
     The liquid metal  20  may be circulated through liquid metal channel  14  using a magnetic or electromagnetic (EM) pump  18 . The pump  18  may be inserted into or attached to the substrate at a feed-through or cavity  19 . As the liquid metal  20  flows, it may draw heat away from device  16  and spread the heat throughout substrate  12  and/or carry the heat to a heat sink  17  that may be in contact with a heat rejection area on the circuit board. By transferring heat away from device  16 , the thermal transfer may be significantly improved over conventional passive thermal spreading materials, including copper. Because the liquid metal cooling may be single phase (no phase change occurs), thermal management system  10 A may not be restrained by the heat flux limits of two phase systems such as heat pipes. While the liquid metal  20  is shown by arrows to flow in a particular direction, according to other exemplary embodiments, the thermal management system could be configured for the liquid metal to flow in the other direction. The liquid metal channel  14  may be filled with liquid metal  20  using ports  15 . The heat sink  17  may be a copper plate, another metal plate, may include cooling fins, or may be any other device capable promoting heat exchange. The circuitry  13  may be high or low power electronic circuits and may also be cooled using liquid metal channel  14 . 
     Referring specifically to  FIG. 2 , as an example, the liquid metal  20  generally flows through liquid metal channel  14  at a first or lowest temperature (e.g., between 15 and 25 degrees Celsius (C), between 18 and 22 degrees C., between 20 and 21 degrees C., at about 20 or 21 degrees C., etc.) in thermal management system  10 A. A substantial portion of substrate  12  and at least a portion of device  16  may be at a second temperature that may be higher than the first temperature (e.g., between 20 and 24 degrees C., between 21 and 23 degrees C., at about 22 degrees C., below 20 degrees C., etc.). A portion of device  16  may be at a third temperature that may be higher than the second temperature (e.g., between 22 and 26 degrees C., between 23 and 25 degrees C., at about 24 degrees C., etc.). A portion of device  16  may be at a fourth temperature that may be higher than the third temperature (e.g., between 23 and 27 degrees C., between 24 and 26 degrees C., at about 25 degrees C., etc.). A portion of device  16  may be at a fifth temperature that may be higher than the fourth temperature (e.g., between 25 and 30 degrees C., between 26 and 29 degrees C., at about 28 degrees C., above 30 degrees C., etc.). It may be noted that while  FIG. 2  illustrates a single heat dissipating device  16 , according to other exemplary embodiments, the substrate  12  may absorb dissipated heat from more than one component. 
     According to various exemplary embodiments, the liquid metal  20  may be an alloy, such as a Gallium-Indium-Tin alloy. According to other exemplary embodiments, alternative liquid metal  20  may be used, including alloys containing any combination of the following: gallium, indium, tin, bismuth, lead, sodium, and potassium. According to some exemplary embodiments, the Gallium-Indium-Tin alloy may be a eutectic composition (e.g. the lowest melting point within the compositional series) with a low boiling point. According to some exemplary embodiments, the Gallium-Indium-Tin alloy may be Galinstan®. Galinstan® may be a generally non-flammable, non-toxic, environmentally friendly liquid metal that may be often used as a mercury replacement in medical equipment. Galinstan® may be generally stable from −19 degrees C. to greater than 1300 degrees C., has approximately thirty times the thermal conductivity of water, and may be insoluble to water and organic solvents. The high boiling point of Galinstan® (greater than 1300 degrees C.) ensures that it will remain in a liquid state under temperatures and pressures likely to be encountered in electronics cooling. 
     Referring to  FIG. 3 , pump  18  may be an electromagnetic pump to circulate a liquid metal  20  through thermal management system  10 A. The pump  18  may provide quiet or silent operation, high reliability, orientation independence, little to no vibration, low power dissipation, and a controllable flow rate for adjustment of thermal spreading capability. The pump  18  may include a ferrous yoke for containing and directing the magnetic field within the yoke and through the liquid metal channel  14  between north and south poles of magnets  22 . A pair of electrodes  24  may transmit a current  38  across liquid metal  20  in a direction perpendicular to the magnetic field generated by magnets  22 . The movement of the current  38  across the magnetic field may impart a force on the liquid metal  20  that may be perpendicular to both the magnetic field and the current  38 . The amount of force generated follows the following equation:
 
 F=I*LxB   (1)
 
     Where I may be current  38  (in amps), L may be a vector, whose magnitude may be the length of the current path (in meters), x may be the vector cross product, and B may be the magnetic field vector measured in Teslas. 
     The magnitude of force may be represented by the variable F, the magnitude of the magnetic field may be represented by the variable B, the amount of current may be represented by the variable I, and the electrode spacing may be represented by the variable L. The pressure of the liquid metal  20  flow may be calculated with the following equation: 
     
       
         
           
             
               
                 
                   P 
                   = 
                   
                     F 
                     
                       L 
                       × 
                       h 
                     
                   
                 
               
               
                 
                   ( 
                   2 
                   ) 
                 
               
             
           
         
       
     
     The pressure may be represented by the variable P, the force by the variable F, the spacing of electrodes  24  by the variable L, and the height of liquid metal channel  14  by the variable h. 
     The pump  18  may be made to occupy a small volume (e.g., approximately one cubic centimeter, less than one cubic centimeter, less than 10 cubic centimeters, greater than 1 cubic centimeter, etc.) and may pump liquid metal  20  with electrical power of less than 10 mW, less than 100 mW, less than 500 mW, etc. The pump  18  includes no moving parts, may require little to no maintenance, may be orientation independent, and may be generally stable at air pressures down to 10 −8  Torr at 500 degrees Celsius. According to various exemplary embodiments, one or both of magnets  22  may be permanent magnets and/or electromagnets including coils to induce a magnetic field. While two electrodes  24  are shown, according to other exemplary embodiments, the current may be generated by a single electrode and a ground, or more than two electrodes. While two magnets  22  are shown, according to other exemplary embodiments a single magnet with a pole extending over opposite sides of liquid metal channel  14 , or more than two magnets could be used. According to various exemplary embodiments, pump  18  may operate at less than about 1 W, between about 100 mW and about 500 mW, less than 500 mw, less than 100 mw, etc. The pump  18  may be coupled to a processor, a user interface, or other digital or analog circuitry to control electric current flow and thereby adjust the pump flow. 
     A coating may be applied to the inner and/or outer perimeter of the liquid metal channel  14  to provide a passivation within the liquid metal channel  14 . According to some exemplary embodiments, the coating may reduce alloying, diffusion, or chemical reaction between components in the channel (e.g., metallic components) and the alloy. The coating may provide at least a substantially hermetic seal around the liquid metal  20  to separate it from the substrate  12  itself and/or the substrate circuitry  13 . According to various exemplary embodiments, the coating may be a thermally conductive coating capable of minimizing the thermal resistance between the liquid metal  20  and the substrate  12  or circuitry  13 . The coating may be composed of any material or materials capable of passivating the liquid metal  20  from the substrate  12  or circuitry  13 , capable of promoting thermal conductivity between the liquid metal  20  and the substrate  12  or circuitry  13 , and/or capable of being applied to the liquid metal channel  14  of the substrate  12 . According to some exemplary embodiments, the coating may only be applied to metallic portions of the liquid metal channel  14  that may be in contact with the liquid metal  20 . 
     According to other exemplary embodiments, the coating may be a coating described in U.S. patent application Ser. No. 11/508,782 filed on Aug. 23, 2006 and entitled “Integrated Circuit Protection and Ruggedization Coatings and Methods,” U.S. patent application Ser. No. 11/784,158 filed on Apr. 5, 2007 and entitled “Hermetic Seal and Hermetic Connector Reinforcement and Repair with Low temperature Glass Coatings,” U.S. patent application Ser. No. 11/732,982 filed on Apr. 5, 2007 and entitled “A Method for Providing Near-Hermetically Coated Integrated Circuit Assemblies,” U.S. patent application Ser. No. 11/732,981 filed on Apr. 5, 2007 and entitled “A Method for Providing Near-Hermetically Coated, Thermally Protected Integrated Circuit Assemblies,” U.S. patent application Ser. No. 11/784,932 filed on Apr. 10, 2007 and entitled “Integrated Circuit Tampering Protection and Reverse Engineering Prevention Coatings and Methods,” and/or U.S. patent application Ser. No. 11/959,225 filed on Dec. 18, 2007 and entitled “Adhesive Applications Using Alkali Silicate Glass for Electronics,” each of which may be herein incorporated by reference in its entirety. 
     Where an electrically conductive contact to the liquid metal  20  may be required, such as at the electrodes  24  within the pump  18 , an electrically conductive coating may be used, which consists of nickel, tantalum, or tungsten metal. Similarly, solid Nickel, Tungsten, or Tantalum wires may be used for the electrodes. 
     Referring to  FIG. 4 , the temperature of substrate  12  and device  16  may be significantly higher (e.g. Temps  4  and  5 ) when pump  18  is turned off in thermal management system  10 A. Only the small portion of substrate  12  may be at the first or lowest temperature (e.g. Temp  1 ) with a larger portion of substrate  12  at the second temperature (e.g. Temp  2 ) and a substantial portion of substrate  12  at the third temperature (e.g. Temp  3 ). The device  16  may operates at elevated temperatures (e.g. Temps  4  and  5 ) when substrate  12  is not pumping liquid metal. Such a condition may affect performance and/or reliability. 
     Referring to  FIG. 5 , according to one exemplary embodiment, the temperature of device  16  may be greatly reduced with the sealed liquid metal channel  14  in thermal management system  10 A as compared to a copper heat sink  26  of the same dimension (as shown in  FIG. 5 ). The temperature of device  16  may rise about eighty degrees C. over the copper heat sink  26  temperature but may rise only about 18.5 degrees Celsius over the cold plate temperature on the substrate  12  of  FIG. 1 . In the substrate  12 , device  16  may contribute to the majority of the thermal gradient. The temperature difference across liquid metal channel  14  may be about 1.6 degrees C. as compared to about seventy degrees C. on copper heat sink  26 . This difference represents a nearly forty-four times improvement in effective thermal conductivity over a copper heat sink  26 . With smaller liquid metal channel  14  dimensions and/or longer liquid metal channel  14  length, the thermal conductivity may be greater. 
     Referring to  FIGS. 6 and 7 , a cross-sectional view of the thermal management system  10 A of  FIG. 1  is presented. The thermal management system  10 A may include multiple layers. The thermal management system  10 A may include a substrate  12  which may include a base layer  28  that defines liquid metal channel  14  and a top layer  30  that covers liquid metal channel  14 . The circuitry  13 , device  16 , and heat sink  17  may be attached to top layer  30 . 
     According to various exemplary embodiments, the liquid metal channel  14  may be formed by etching substrate  12  (e.g., wet etching, plasma etching, silk screen printing, photoengraving, PCB milling, die cutting, stamping, etc.) during fabrication. The substrate  12  may include any material used to make circuit boards or heat sinks including copper, any conductive material, or any non-conductive material. In one example, substrate  12  may include thermally conductive inserts or other devices for increased heat dissipation. 
     For example, the etching may etch away a base layer  28  of copper (or other layer) on top of a non-conductive layer to form the liquid metal channel  14 . Alternatively, the etching may etch away a base layer  28  of non-conductive material (or both a layer of copper and a non-conductive layer) to form liquid metal channel  14 . The liquid metal channel  14  may then be coated and/or sealed with a thermally conductive coating. Thereafter, another conductive (e.g., a heat sink  17 ) or non-conductive layer (e.g., top layer  30 ) may be placed on top of the etched base layer  28 . Alternatively, the etched base layer  28  may be placed on top of another layer or between two other layers. The non-etched layers may also include a coating to facilitate greater thermal conductivity and/or sealing with thermal management system  10 A. The coating may be applied to liquid metal channel  14 , base layer  28  and/or top layer  30  during etching or after etching and before assembly. The coating may also be applied after partial assembly (e.g., after an etched layer is placed on a base layer) and before any additional layers are added. 
     According to various exemplary embodiments, the width of liquid metal channel  14  may be between 5 and 50 mm. According to various exemplary embodiments, the height of liquid metal channel  14  may be as small as 10 microns and as large 2000 microns. According to various exemplary embodiments, the length of liquid metal channel  14  may be between typically 5 and 200 cm. The values of these dimensions, especially the maximum values, may be primarily dictated by geometric requirements of the system that may be being thermally managed with the liquid metal channel  14  rather than limitations of the liquid metal cooling approach itself. 
     According to various exemplary embodiments, the general cross-sectional shape of liquid metal channel  14  may be square, rectangular, triangular, hexagonal, trapezoidal, or any other shape. While liquid metal channel  14  is shown to have a specific rectangular-shaped flow path, according to other exemplary embodiments, the path may be of any shape or direction that facilitates the cooling of device  16 . 
     According to some exemplary embodiments, the liquid metal  20  may be added to liquid metal channel  14  during fabrication before a coating seals liquid metal channel  14  or before a top layer  30  is placed on top of an etched base layer  28 . According to other exemplary embodiments, a reservoir may feed liquid metal  20  to liquid metal channel  14 . The reservoir may be etched or otherwise formed into substrate  12 . Alternatively, the reservoir may be external to substrate  12  (e.g., attached to substrate  12 ) and coupled to liquid metal channel  14 . The substrate  12  may include a heat sink  17  and/or fan at or near an end of substrate  12  opposite from a heat source (e.g. a device  16 ) to help cool the liquid metal  20  flowing from device  16 . Alternatively or additionally, an external reservoir may include a heat sink  17  and/or fan at or near an end of substrate  12  opposite from the heat source (e.g. a device  16 ) to help cool the liquid metal  20  flowing from device  16 . 
     Referring to  FIGS. 8 and 9 , a thermal management system  10 B is illustrated. Similar to thermal management system  10 A, thermal management system  10 B may include a closed-loop liquid metal channel  14  in substrate  12  containing a device  16  to be cooled by liquid metal  20  flowing in the liquid metal channel  14 . According to various exemplary embodiments, the substrate  12  may be a printed circuit board, a thermal spreader (which may be rigid or mechanically flexible), or any other substrate to which at least one power dissipating device, such as an electronic component, may be attached or interfaced. According to various exemplary embodiments, the device  16  may be a high power electronic circuit (e.g., a rectifier, an inverter, another power semiconductor device, etc.), a microprocessor, and/or any other analog or digital circuit that generates heat. 
     The liquid metal  20  may be circulated through liquid metal channel  14  using a magnetic or electromagnetic (EM) pumping mechanism  18 . As the liquid metal  20  flows, it may draw heat away from device  16  and spread the heat throughout substrate  12  and/or carry the heat to a heat sink  17  that may be in contact with a heat rejection area on the circuit board. By transferring heat away from the device  16 , the thermal transfer may be significantly improved over conventional passive thermal spreading materials, including copper. Because the liquid metal cooling may be single phase (no phase change occurs), thermal management system  10 A may not be restrained by the heat flux limits of two phase systems such as heat pipes. While the liquid metal  20  is shown by arrows to flow in a particular direction, according to other exemplary embodiments, the thermal management system could be configured for the liquid metal to flow in the other direction. The heat sink  17  may be a copper plate, another metal plate, may include cooling fins, or may be any other device capable promoting heat exchange. The circuitry  13  may be high or low power electronic circuits and may also be cooled using liquid metal channel  14 . 
     In contrast to thermal management system  10 A, thermal management system  10 B may not include a separate power source for the electromagnetic pump  18 . Instead, the current for powering the electromagnetic pump  18  may be obtained from the power circuitry associated directly with the device  16 . 
     For example, as shown in  FIGS. 8 and 9 , the device  16  may be operably coupled to current transmission circuitry  34  (e.g. device circuitry  34 A and/or device circuitry  34 B. The current transmission circuitry  34  may be operably coupled to the pump  18 .  FIGS. 8 and 9  illustrate the pump  18  operably coupled to the device circuitry  34 B of device  16 . However, the pump  18  may be operably coupled to the device circuitry  34 A of device  16  without departing from the scope of the invention. 
     In such configurations, the current flowing into or out of the device  16  may provide an electromagnetic force for pumping the liquid metal  20 . As the heat generated by a device  16  is generally proportional to the current provided to the device  16 , such a configuration may serve to automatically control the pumping velocity of liquid metal  20  according to the current provided to the device. 
     The pump  18  may include a ferrous yoke for containing and directing the magnetic field within the yoke and through the liquid metal channel  14  between north and south poles of magnets  22 . A pair of electrodes  24  may transmit a current  38  across liquid metal  20  in a direction perpendicular to the magnetic field generated by magnets  22 . The movement of the current  38  across the magnetic field may impart a force on the liquid metal  20  that may be perpendicular to both the magnetic field and the current  38 . 
     According to various exemplary embodiments, one or both of magnets  22  may be permanent magnets and/or electromagnets including coils to induce a magnetic field. While two electrodes  24  are shown, according to other exemplary embodiments, the current may be generated by a single electrode and a ground, or more than two electrodes. While two magnets  22  are shown, according to other exemplary embodiments a single magnet with a pole extending over opposite sides of liquid metal channel  14 , or more than two magnets could be used. According to various exemplary embodiments, pump  18  may operate at less than about 1 W, between about 100 mW and about 500 mW, less than 500 mw, less than 100 mw, etc. The pump  18  may be coupled to a processor, a user interface, or other digital or analog circuitry to control electric current flow and thereby adjust the pump flow. 
     It will be recognized one knowledgeable in the art that pump  18  may be disposed in either an upstream or downstream position in relation to the device  16  with respect to the current flow relative to the device  16  without departing from the scope of the present disclosures. 
     In instances where the current provided to the device  16  exceeds the current needed to provide adequate pumping action of liquid metal  20 , a current shunt  36  element may be provided to reduce the current  38  applied across the liquid metal channel  14 . For example, the current shunt  36  may be operably coupled to one of the electrodes  24  via electrode circuitry  34 B- 1 . The current shunt  36  may be operably coupled to a ground plane  32  by current shunt circuitry  34 B- 2 . In such a configuration, the amount of current provided to the electrodes  24  may be modified through the transmission characteristics of the current shunt  36  so as to control the pumping velocity range of the pump  18 . 
     The thermal management system  10 A and/or the thermal management system  10 B may provide a low cost, simple, reliable, and/or integrated method for spreading heat away from high power devices. Integrating such a technology into an electronic substrate may allow direct heat removal from high power integrated circuits (IC) and passive devices while also providing electrical interconnect to these components. While this approach could be used for almost any type of electronics packaging, specific examples of suitable applications include RF Power Amplifiers and Light Emitting Diode (LED) light arrays, which may otherwise require that a heat sink or heat spreader be bonded to the back side of the electronic substrate so that both sides of the circuit card may be populated with electronic components. Another exemplary application may include the use of an electronic substrate with embedded liquid metal cooling channels as part of an antenna array, such as a phased array antenna. 
       FIGS. 10 and 11  illustrate operational flows representing example operations related to proportional cooling with liquid metal. However, it should be understood that the operational flows may be executed in a number of other environments and contexts, and/or in modified versions of  FIG. 1 . Also, although the various operational flows are presented in the sequence(s) illustrated, it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. 
     Referring to  FIG. 10 , after a start operation, an exemplary operational flow  1000  moves to a transmitting operation  1002 . Operation  1002  illustrates transmitting a current to a device. For example, as shown in  FIGS. 8 and 9 , a device circuitry  34 A may transmit a current from a power source (not shown) to a device  16 . 
     Operation  1004  illustrates, transmitting a current from the device across a circuit board channel comprising a liquid metal. For example, as shown in  FIGS. 8 and 9 , device circuitry  34 B may transmit a current to pump  18  from the device  16 . The pump  18  may transmit a current across liquid metal channel  14  and through liquid metal  20 . 
       FIG. 10  further illustrates an example embodiment where the example operational  1004  may include at least one additional operation. Additional operations may include an operation  1006 , operation  1008 , operation  1010  and/or operation  1012 . 
     Operation  1006  illustrates transmitting a current from the device to an electrode. For example, as shown in  FIGS. 8 and 9 , device circuitry  34 B- 1  may transmit a current to one or more electrodes  24  of pump  18 . 
     Operation  1008  illustrates inducing a velocity of the liquid metal associated with the current transmitted across the circuit board channel comprising the liquid metal. For example, as shown in  FIGS. 8 and 9 , electrodes  24  may transmit a current  38  across the liquid metal channel  14  and through liquid metal  20 . The movement of current  38  may exert an electromagnetic force on the liquid metal  20  which may accelerate the liquid metal  20  to a velocity within the liquid metal channel  14 . 
     Operation  1010  illustrates inducing a velocity in the liquid metal proportional to current usage of the device. For example, as shown in  FIGS. 8 and 9 , the current  38  may be an output current from device  16 . As such, current  38  may be proportional to the current usage of the device  16 . The resulting electromagnetic force on the liquid metal  20  (and corresponding velocity of the liquid metal  20 ) may be proportional to the current  38 . 
     Operation  1012  illustrates transmitting a current from the device to a current shunt. For example, as shown in  FIGS. 8 and 9 , device circuitry  34 B may transmit a current from the device  16  to a current shunt  36 . The current shunt  36  may transmit a current via current shunt circuitry  34 B- 2  to the ground plane  32 . The amount of current  38  transmitted across the liquid metal channel  14  and through liquid metal  20  may be modified through the transmission characteristics of the current shunt  36  so as to control the pumping velocity range of the pump  18 . 
     Referring to  FIG. 11 , after a start operation, an exemplary operational flow  1100  moves to a transmitting operation  1102 . Operation  1102  illustrates transmitting a current from the device across a circuit board channel comprising a liquid metal. For example, as shown in  FIGS. 8 and 9 , a pump  18  may transmit a current received from a power source (not shown) across liquid metal channel  14  and through liquid metal  20 . 
     Operation  1104  illustrates, transmitting the current transmitted across the circuit board channel comprising a liquid metal to a device. For example, as shown in  FIGS. 8 and 9 , device circuitry  34 B may transmit a current received from pump  18  to a device  16 . 
       FIG. 11  further illustrates an example embodiment where the example operational  1102  may include at least one additional operation. Additional operations may include an operation  1106 , operation  1108  and/or an operation  1110 . 
     Operation  1106  illustrates transmitting a current to one or more electrodes. For example, as shown in  FIGS. 8 and 9 , one or more electrodes  24  of pump  18  may receive a current from a power source (not shown). 
     Operation  1108  illustrates inducing a velocity of the liquid metal associated with the current transmitted across the circuit board channel comprising the liquid metal. For example, as shown in  FIGS. 8 and 9 , electrodes  24  may transmit a current  38  across the liquid metal channel  14  and through liquid metal  20 . The movement of current  38  may exert an electromagnetic force on the liquid metal  20  which may accelerate the liquid metal  20  to a velocity within the liquid metal channel  14 . 
     Operation  1110  illustrates inducing a velocity in the liquid metal proportional to current usage of the device. For example, as shown in  FIGS. 8 and 9 , the current  38  may be an output current from device  16 . As such, current  38  may be proportional to the current usage of the device  16 . The resulting electromagnetic force on the liquid metal  20  (and corresponding velocity of the liquid metal  20 ) may be proportional to the current  38 . 
       FIG. 11  further illustrates an example embodiment where the example operational  1104  may include at least one additional operation. Additional operations may include an operation  1112 . 
     Operation  1112  illustrates powering the device with the current transmitted across the circuit board channel comprising a liquid metal. For example, as shown in  FIGS. 8 and 9 , device circuitry  34 B may transmit a current from the pump  18  to the device  16 . The device  16  may utilize the current received from the pump  18  to power its circuitry. 
     While the detailed drawings, specific examples, detailed algorithms and particular configurations given describe preferred and exemplary embodiments, they serve the purpose of illustration only. The embodiments disclosed may be not limited to the specific forms shown. For example, the methods may be performed in any of a variety of sequence of steps or according to any of a variety of mathematical formulas. The configurations shown and described may differ depending on the chosen performance characteristics and physical characteristics of the weather radar and processing devices. For example, the type of system components and their interconnections may differ. The systems and methods depicted and described may be not limited to the precise details and conditions disclosed. The flow charts show preferred exemplary operations only. The specific data types and operations are shown in a non-limiting fashion. Furthermore, other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of the application as expressed in the appended claims.