US20070159797A1 - Heat exchange apparatus - Google Patents

Abstract

In one embodiment, heat exchange device is provided, which includes a printed circuit board with a multichip module mounted on the printed circuit board. A cold plate is positioned on the multichip module and a bolster plate on a side of the printed circuit board opposite the cold plate. A fastener secures the bolster plate and the cold plate with the printed circuit board, and, urges the cold plate against the multichip module and the multichip module against the printed circuit board. The cold plate may form a lid to the multichip module. The multichip module may include a pin electronics die abutting the cold plate. In some embodiments the bolster plate is a compression plate.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This application is a divisional of pending U.S. application Ser. No. 10/882,433, herein incorporated by reference in its entirety.
BACKGROUND
• Automated test equipment, or ATE, provides semiconductor manufacturers the capability of individually testing each and every semiconductor device fabricated during production. The testing is usually carried out at both the wafer level and the packaged-device level to ensure operability of the devices before reaching the marketplace.
• Modern semiconductor devices typically have anywhere from thirty-two to over one-thousand pins, generally requiring a corresponding number of channels in the semiconductor tester to thoroughly verify the operation of the device. Each channel usually comprises a signal path including the necessary pin electronics for sending and/or receiving test signals to and from a pin on the DUT. In conventional testers, to maximize component density and minimize the size of the tester, the channels are often formed on printed circuit boards resident within a testhead. The testhead is separated from the main body of the tester for coupling to the DUTs that are mounted on a prober or handler.
• Because of the relatively high concentration of circuit boards within a conventional testhead, specialized cooling systems are generally employed to maintain a stable thermal environment. Some prior systems have employed air cooling, which typically includes elaborate ducting that takes up valuable space within the testhead. As a result, these air cooling systems contribute to a larger overall footprint for the tester. Moreover, because the airflow must overcome the resistive effects of ducting, nozzles and the uneven shapes and surfaces of the boards, the air cooled systems tend to not be as efficient as desired.
• Other approaches have included liquid cooling systems that circulate a fluid, typically water, from a liquid cooler, i.e. a refrigeration unit, and past the heat producing electronic components, i.e. microchips, and back to the cooler. Liquid is passed through cooling blocks, which are attached to the electronic components, to allow the heat to transfer from the components to the liquid. In these systems, the cooling blocks are attached to one another with tubes or hoses, in series to form a single path or channel for the liquid to pass though. That is, these systems flow the liquid from the cooling unit, which typically includes a pump, to a first cooling block, where heat is transferred from the electronic component, which the cooling block is mounted on, into the liquid. Then the liquid leaves the first cooling block through a connecting tube to a second cooling block, where heat is again transferred into the liquid from another electronic component. The liquid continues to move through a series of cooling blocks in succession, having heat transferred into it at each cooling block, until it returns to the cooling unit.
• Because the liquid is heated each time it passes through a cooling block, the temperature varies unpredictably with each cooling block in the series of cooling blocks. That is, with such cooling systems each electronic component will be operating at a different temperature, with the temperature rising along the path of the liquid through the cooling blocks.
• Lately, the trend has been with modern electronic components, especially those used in current automated test equipment, of becoming more and more sensitive to temperature levels, and any fluctuations thereof. To optimize performance of these components and to obtain uniform performance with among a set of components, a stable and common temperature level is desired across all the components. This is difficult to achieve with the variable liquid temperatures provided by the prior liquid cooling systems.
• Therefore, a need exists for a cooling system that provides an uniform, predictable and consistent cooling environment for each of the electronic components being cooled. Such a system should allow for ease of access to reduce the time needed for servicing and, as a result, minimize overall equipment downtime.
SUMMARY
• In at least one embodiment, heat exchange device is provided, which includes a printed circuit board with a multichip module mounted on the printed circuit board. A cold plate is positioned on the multichip module and a bolster plate is located on a side of the printed circuit board opposite the cold plate. A fastener secures the bolster plate and the cold plate with the printed circuit board, and, urges the cold plate against the multichip module and the multichip module against the printed circuit board. In some embodiments, the cold plate forms a lid to the multichip module. The multichip module may include a pin electronics die abutting the cold plate. In some embodiments the bolster plate is a compression plate.
• In some embodiments, the heat exchange apparatus includes an intake manifold, in fluid communication with each heat exchanger, which is capable of providing a heat exchange medium separately to each heat exchanger. Multichip modules mounted to a card may be positioned between the heat exchanger and the card such that heat can transfer between each multichip module and a respective heat exchanger. A bolster plate is positioned on a side of the card opposite the multichip modules and the heat exchanger. A fastener secures the bolster plate and the heat exchanger with the card, and the heat exchanger with the multichip module.
BRIEF DESCRIPTION OF THE DRAWINGS
• The features and advantages of the present invention will be better understood with regard to the following description, appended claims, and accompanying drawings where:
• FIG. 1 shows a top cut-away view of a parallel heat exchange system in accordance with at least one embodiment of the present invention.
• FIG. 2 shows a top cut-away view of a portion of a heat exchange system in accordance with at least one embodiment of the present invention.
• FIG. 3 shows a side view of a portion of a heat exchange system in accordance with at least one embodiment of the present invention.
• FIG. 4ashows a top cut-away view of a heat exchange system in accordance with at least one embodiment of the present invention.
• FIG. 4bshows a side cut-away view of a portion of a heat exchange system in accordance with at least one embodiment of the present invention.
DESCRIPTION
• Some embodiments of the present invention include a heat exchange system which functions to provide an even distribution of the heat exchange medium across each of the heat exchangers. This distribution can include providing even pressures, flow rates as well as temperatures and composition of the medium. This distribution allows the flows of the medium to be predictable and consistent through each of heat exchangers. In turn, an even heat exchange capacity, i.e. heat transfer rate, over each of the heat exchangers is achieved. As such, the temperatures of each of the heat exchangers, and therefore the electronic components attached thereto, can be kept at the same temperature, or within a relatively narrow range of temperatures.
• The even distribution of the heat exchange medium is achieved in part with use of an intake manifold and an exhaust manifold. By having each of heat exchangers attached to a single common supply of the heat exchange medium, the distribution to each heat exchanger can be kept even.
• The ability of the parallel heat exchange system to keep the heat transfer, and thus the temperature, the same across all of the heat exchanges and their associated electronic components, is in direct contrast to the serial cooling systems, described above. Because a serial system flows coolant through one cooling block after another, in succession, the conditions, i.e. temperature, of the coolant will be altered after passing through each cooling block. As a result, the temperatures across the cooling blocks vary along the path of the flow of the coolant.
• In temperature sensitive applications, such as cooling of electronic components, i.e. chip modules, the heat exchange systems must be capable of maintaining relative constant temperatures on each component. Failure to do so can result in dramatic reductions, or errors, in performance, and/or damage to the components. More specifically, adverse temperatures can affect timing signals of chips, and, due to increased electrical resistance, certain analog functions, as well as increased noise.
• On the other hand, predictability in cooling allows for more efficient component designs, thereby increasing performance and lowering costs. With narrower operating temperature ranges, components can be designed to operate at higher frequencies and to use less power.
• With multichip modules, or MCMs, used in automated test equipment, or ATE, sensitive pin electronics die used within the MCM typically can not meet their performance specifications without tightly controlling their operating temperatures. In some embodiments of the present invention, the temperature range of the MCMs have been found to be able of being maintained within a ±1° C. temperature range.
• FIG. 1 shows a top view cut-away of a parallel heat exchange system in accordance with at least one embodiment of the present invention. As shown, a heat exchange orcooling system100 is positioned on a printed circuit board orcard160, such that it is capable of cooling each of the components ordevices170. By being arranged to supply cooling to each of the devices in a parallel arrangement, theheat exchange system100 is capable of maintaining the temperature of each device at the same, or at least substantially the same, temperature. That is, all the devices can be keep in a relatively narrow common range of temperatures. This can result in improved and more uniform performance and provide a more common life span of each device, reducing the overall amount of servicing required.
• Thecooling system100 includes an inlet orintake manifold110, inlet or intake tubes orhoses120,heat exchangers130, outlet or exhaust tubes orhoses140 and an outlet orexhaust manifold150. Thecard160 includes anedge162. Thedevices170 are mounted on thecard160 adjacent theedge162. The flow directions of the heat exchange medium (not shown), in this embodiment, are shown generally by the arrows A1, A2, A3, A4, A5 and A6.
• Theintake manifold110 functions to allow an incoming flow of the heat exchange medium to be evenly distributed over a set of tubing connected to themanifold110. Theintake manifold110 includes a common ordistribution region112,openings114, and anopen end116. The general flow direction of the heat exchange medium through theintake manifold110 is shown by the arrow A2.
• Depending on the embodiment, theintake manifold110 can be mounted on thecard160, positioned over thecard160, or positioned adjacent to thecard160. With theintake manifold110 mounted on to thecard160 it allows theheat exchange system100 and thecard160 to be a single unit, making installation, removal and servicing of the combined unit easier and quicker. Which in turn can reduce the time and cost of maintenance and repair.
• The heat exchange medium used in the present invention can be any of a variety of substances including a liquid or a gas. Usable liquids include inert fluids and other fluids, such as water, flourinert dielectric fluid, HFE and FC77 both available from 3M corp. of St. Paul, Minn. Usable gases include air, helium, as well as other gases. In the embodiment shown inFIG. 1 an inert fluid can be used as the heat exchange medium.
• Thedistribution region112 receives the heat exchange medium from an external source (not shown), such as a cooling system, a refrigeration unit, a heat exchanger, a heater, pump, reservoir or the like. As the medium moves into thedistribution region112, it is applied evenly to each of theopenings114. The specific size and shape of thedistribution region112 can vary and depending on factors including the flow rates into and out of thedistribution region112, and the properties of the heat exchange medium, i.e. pressure, compressibility, viscosity, and the like. In some embodiments, as shown, thedistribution region112 is significantly larger in cross-section than theopenings114 and the opening of theopen end116. This allows the flow rate of the heat exchange medium to reduce upon entering thedistribution region112 and facilitates even distribution to theopenings114.
• Theopenings114 are positioned along theintake manifold110 and function to allow flow to be directed into each of theintake tubes120 attached thereto. While shown being positioned along a common side ofintake manifold110, in other embodiments theopenings114 can be on other sides, or about themanifold110. While the size and shape of theopenings114 can vary, to achieve a balanced and even flow through each of the openings, theopenings114 typically have a common size and shape. The particular size and shape of theopenings114 is dependent on the particular application and can vary depending on factors including the desired flow rate through theopenings114, and the properties of the heat exchange medium, as noted above.
• Theintake manifold110 also includes theopen end116, which has anopening117, allowing the flow of heat exchange medium into the manifold110 from an external source (not shown). The external source can be a coolant source. The size and shape of theopening117 can vary depending on the embodiment, and on factors including the flow rate and the properties of the heat exchange medium. Theopen end116 can also include a connector orintake connector118, which functions to attach the tube or hose from the external source to theintake manifold110. Theconnector118 can include a valve, or valves, to prevent or limit any leakage of the heat exchange medium. Theconnector118 can also be positioned away from theopen end116 along the tube from the external source. Theconnector118 can be a quick-disconnect connector to allow the external source tube to be relatively quickly disconnected from themanifold110. Such a quick-disconnect connector facilitates the quick removal of thecard160 from a test head, or any similar apparatus. This in turn allows for reduced service time and less equipment down time. Also, this provides more flexibility in allowing individual cards to be serviced without impacting other cards in the equipment.
• Theintake tubes120 are connected between theintake manifold110 and theheat exchangers130, and function to carry the heat exchange medium therebetween. Eachintake tube120 includes aninlet122 and anoutlet126. The general flow direction is shown by the arrow A3. Theintake tubes120 can be of any of a variety of different materials including rubber, stainless steel, aluminum, plastic, vinyl, and copper. Theintake tubes120 can be compliant and/or flexible tubing which may be required for adjusting the alignment of the any connectors placed along theintake tubes120, as described below.
• The size and shape of theintake tubes120 can vary depending on the particular application. Factors including the desired flow rate and the properties of the heat exchange medium determining the size and shape used for theintake tubes120. Theoutlet126 is shown being attached to theheat exchanger130 along one of its sides, however, theoutlet126 can be attached toheat exchanger130 at any of a variety of different points about theheat exchanger130, depending on the particular configuration of the inlet and outlet of theheat exchanger130.
• Between theinlet122 and theoutlet126, theintake tube120 can include a connector orfirst connector124 which allows theintake tube120 to be separated into two portions on either side of theconnector124. Theconnector124 can include a valve, or valves, to prevent or limit any leakage of the heat exchange medium. Theconnector124, along with a similar connector on theexhaust tubes140, as detailed below, allows theheat exchanger130 to be removed from coolingsystem100 without removing the rest of thecooling system100 from thecard160. As a result, theheat exchanger130 may be removed to facilitate access to thedevice170 or structure being cooled by theheat exchanger130, i.e. a MCM, as shown. This allows individual components to be serviced without impacting other components on the board. Also, with theheat exchanger130 and thedevice170 being mounted to each other in an integrated unit, as detailed below, theconnector124 facilitates the removal of the unit from thechannel card160. Theconnector124 can be a quick-disconnect connector such as a QD connector available from Eaton Aeroquip, Inc. located in Maumee, Ohio. The use of such a quick-disconnect further reduces the time and effort need to disconnect the tube. In turn, this further reduces the service time and equipment down time. In some embodiments, theconnector124 is referred to as an inlet cold plate connector.
• Theheat exchanger130 functions to transfer heat between device it is positioned with, i.e. mounted upon, and the heat exchange medium. In some embodiments, as that shown, theheat exchanger130 functions to cool thedevice170 that is positioned under theheat exchanger130. In certain embodiments, thedevice170 has the coldplate bonded such that the cold plate is in close proximity to components of the device, i.e. the bare or exposed dies in an MCM. As noted above and as further detailed below, theheat exchanger130 and thedevice170 can be mounted together in an integrated unit.
• The size and shape of theheat exchanger130 can vary depending on the requirements of the particular application. For example, the size of the heat exchanger can be directly dependent on the amount of heat that must be transferred from the device it is mounted to, and the device's surface area available for the heat transfer. Theheat exchanger130 can be a cold plate with a variety of different configurations, as further described below.
• Theheat exchanger130 includes aninlet132 and anoutlet134, which depending on the configuration of theheat exchanger130, can be located at different positions about theheat exchanger130.
• Theheat exchanger130 can be of any of a variety of different materials which aid in the heat transfer, including materials with high heat transfer rates such as copper, brass, aluminum and the like.
• Theexhaust tubes140 are connected between theheat exchangers130 and theexhaust manifold150, and function to carry the heat exchange medium therebetween. Eachexhaust tube140 includes aninlet142 and anoutlet146. The general flow direction is shown by the arrow A4. Theexhaust tubes140 can be of any of a variety of different materials including rubber, stainless steel, aluminum, plastic, vinyl, copper. Theexhaust tubes140 can be compliant and/or flexible tubing which may be required for adjusting the alignment of the any connectors placed along thetubes140, as described below.
• The size and shape of theexhaust tubes140 can vary depending on the particular application, with factors including the desired flow rate and the properties of the heat exchange medium determining the size and shape of theexhaust tubes140. Theinlet142 is shown being attached to theheat exchanger130 along one of its sides, however, theinlet142 can be attached toheat exchanger130 at any of a variety of different points about theheat exchanger130, depending on the particular configuration of theinlet132 andoutlet134 of theheat exchanger130.
• Between theinlet142 and theoutlet146, theexhaust tube120 can include a connector orsecond connector144 which allows theexhaust tube120 to be separated into two portions on either side of theconnector144. Theconnector144 can include a valve, or valves, to prevent or limit any leakage of the heat exchange medium. Theconnector144, along with theconnector124 on theintake tube120, allows theheat exchanger130 to be removed from coolingsystem100, without removing the rest of thecooling system100 from thecard160. As a result, theheat exchanger130 may be removed to facilitate access to thedevice170 or structure being cooled, i.e. the MCM, as shown. Also, with theheat exchanger130 and thedevice170 being mounted to each other in an integrated unit, as detailed below, theconnector144 facilitates the removal of the unit from thecard160. Theconnector144 can be a quick-disconnect connector such as a QD connector available from Eaton Aeroquip, Inc. located in Maumee, Ohio. The use of such a quick-disconnect further reduces the time and effort need to disconnect the tube. In turn, this further reduces the service time and equipment down time. In some embodiments, theconnector144 is referred to as an inlet cold plate connector.
• Theexhaust manifold150 functions to collect an outgoing flow of the heat exchange medium from theexhaust tubes140 to be sent out of thesystem100. The heat exchange medium can be sent to a coolant receptor. Theexhaust manifold150 includes a common orcollection region152,openings154, and anopen end156. The general direction flow of the heat exchange medium through theexhaust manifold150 is shown by the arrow A5.
• Depending on the embodiment, theexhaust manifold150 can be mounted on thecard160, or positioned over or adjacent to thecard160. With theexhaust manifold150 mounted on to thecard160, theheat exchange system100 and thecard160 are a single unit. This makes installation, removal and servicing of the combined unit easier and quicker, reducing the time and cost of maintenance and repair.
• Thecollection region152 can direct the heat exchange medium to an external device (not shown), such as a cooling system, a refrigeration unit, a heat exchanger, a heater, pump, reservoir or the like. The specific size and shape of thecollection region152 can vary and depending on factors including the flow rates, and the properties of the heat exchange medium, i.e. pressure, compressibility, viscosity, and the like. In some embodiments, such as that shown, the collection region is significantly larger in cross-section than theopenings154 and the opening of theopen end156.
• Theopenings154 are positioned along theexhaust manifold150 and function to allow flow to be directed from each of theexhaust tubes140 attached thereto into thecollection region152. While shown being positioned along a common side of theexhaust manifold150, in other embodiments theopenings154 can be on other sides, or about themanifold150. While the size and shape of theopenings154 can vary, to achieve an even flow through each of the openings, theopenings154 typically have a common size and shape. The particular size and shape of theopenings154 is dependent on the particular application and can vary depending on factors including the desired flow rate through theopenings154, and the properties of the heat exchange medium, as noted above.
• Theexhaust manifold150 also includes anopen end156. Theopen end156 has an opening157 which allows the flow of heat exchange medium from the manifold150 to an external location (not shown). The size and shape of the opening157 can vary depending on the embodiment, and on factors including the flow rate and the properties of the heat exchange medium. Theopen end156 can also include a connector orexhaust connector158, which functions to attach the tube or hose to the external location to theexhaust manifold150. Theconnector158 can include a valve, or valves, to prevent or limit any leakage of the heat exchange medium. Theconnector158 can also be positioned away from theopen end156 along the tube to the external source. Theconnector158 can be a quick-disconnect connector to allow the external tube to be relatively quickly disconnected from theexhaust manifold150. Such a quick-disconnect connector, in conjunction with theconnector118 on theintake manifold110, facilitates the quick removal of thecard160 from a test head, or any similar apparatus. This in turn allows for reduced service time and less equipment down time. Also, this provides more flexibility in allowing individual cards to be serviced with impacting other cards in the equipment.
• Depending on the embodiment of the present invention, thecard160 can be a channel card or a printed circuit board. Thedevice170 can be an electronic component, such as a multichip module, or MCM, having pin electronics dies.
• An example of a cooling apparatus or cooling plate is set forth in U.S. Pat. No. 5,871,042, entitled LIQUID COOLING APPARATUS FOR USE WITH ELECTRONIC EQUIPMENT, by Gutfeldt, et al., issued Feb. 16, 1999, which is hereby incorporated reference in its entirety.
• FIG. 2 shows a top cut-away view of a portion of a heat exchange system in accordance with at least one embodiment of the present invention. A heat exchanger or cooling plate orcold plate200 includes astructure210, a inlet orintake connector220 and a outlet orexhaust connector230. The general flow direction of a heat transfer medium (not shown) shown by the arrows B1, B2, B3, B4 and B5. Thecooling plate200 can be removed from the rest of the heat exchange system by theconnectors220 and230 for repair, maintenance or replacement of the cooling plate and/or the device (not shown) that it is cooling.
• In the embodiment shown, thestructure210 of thecooling plate220 includes anexternal frame211, adivider212,channel214, alower plate216, an upper plate (not shown), aninlet218 and anoutlet219.
• Theexternal frame211 and thedivider212 form thechannel214, which directs the coolant through thecooling plate200, as shown generally by arrows B2, B3 and B4. One example of how the flow can be directed to selectively flow first over certain regions, which are positioned above particular components of the device being cooled, is shown inFIG. 2. A variety of other embodiments with different internal flow patterns are possible by reshaping and rearranging theframe211, thedivider212 and thechannel214.
• In the embodiment of the present invention shown inFIG. 2, thedivider212 functions to direct the flow such that it first flows over the regions X1 and X2 then on to region X3. The regions X1, X2 and X3 can show the positions of components, i.e. chips or dies, of the device set below thecooling plate200. In some embodiments, the regions X1 and X2 locate pin electronics dies and the region X3 locates a digital ASIC chip. In these embodiments, since pin electronics dies are typically more sensitive to temperature levels, and variations thereof, than digital ASIC chips, the flow of the coolant is directed first over the regions X1 and X2. In certain embodiments, the pin electronics dies are most sensitive to temperature effects along a specific edge of the die. By setting this edge of the die as the leading edge, relative to the flow of the heat transfer medium, the sensitivity of the die to heat can be minimized.
• As a result, with the embodiment ofFIG. 2, uniform cooling can be provided to the pin electronics dies in each of the devices, i.e. MCMs, being cooled by each of the coolingplates200 of a heat exchange system.
• Below thechannel214 is thelower plate216 and above the channel an upper plate (not shown in the cut-away of FIG. 2). Thelower plate216 can be a heat transfer plate, which can be of a material which allows a high rate of heat transfer, such as copper, brass, aluminum and the like.
• Thestructure210 also includes theinlet218 and theoutlet219 for allowing the flow into and out of thecooling plate200. Positioned upstream from theinlet218 is theinlet connector220 and positioned downstream from the outlet is theoutlet connector230. Theconnector220 and230 can also be positioned in contact with, or part of, thestructure210. Theconnectors220 and230 can include a valve, or valves, to prevent or limit any leakage of the heat exchange medium. In some embodiments, theinlet connector220 and theoutlet connector230 are quick-disconnect connectors to facilitate the removal of thecooling plate200 from the heat exchange system. Using quick-disconnect connectors allows for a reduction in the time need to remove thecooling plate200, reducing time need for servicing and equipment downtime. Usable quick-disconnect connectors include as QD connectors available from Eaton Aeroquip, Inc. located in Maumee, Ohio.
• In certain embodiments of the present invention, thecooling plate200 ofFIG. 2, can be used as theheat exchanger130 in theheat exchange system100 ofFIG. 1.
• FIG. 3 shows a side cross-sectional view of a portion of a heat exchange system in accordance with at least one embodiment of the present invention. The embodiment shown inFIG. 3 is anintegrated unit300 that includes aheat exchanger310,fasteners320, a backing or bolsterplate330, a card ordevice board340 and adevice350. Flow of a heat exchange medium is generally shown by arrows C1 and C2.
• With theheat exchanger310, thedevice board340 and thedevice350 all secured together by thefasteners320, theintegrated unit300 provides several functions. With theheat exchanger310 and thedevice350 abutted, the transfer of heat therebetween is facilitated. Since theheat exchanger310 is secured over thedevice350, theheat exchanger310 also functions as a lid for thedevice350, protecting its components. Also, with thefasteners320 urging theheat exchanger310 down against thedevice350, theheat exchanger310 can function as a compression plate to secure the device in theboard340. As a result, by using theheat exchanger310 as not only a heat exchanger, but also a lid and a compression plate, theintegrated unit300 eliminates the need for additional components, reducing cost and complexity.
• Theheat exchanger310 includes anoutlet312, achamber314, aheat exchange plate316,feet317 and mounts318. Theheat exchanger310 is capable of transferring heat between thedevice350 and the heat transfer medium (not shown) flowing through theheat exchanger310. The size and shape of theheat exchanger310 can vary depending on the requirements of the particular application. For example, the size of theheat exchanger310 can be directly dependent on the amount of heat that must be transferred from thedevice350 and the surface area available for the heat transfer. As shown, theheat exchanger310 is a cold plate.
• Theheat exchanger310 can be of any of a variety of different materials which allow heat transfer, including materials with high heat transfer rates such as copper, brass, aluminum and the like. Theheat exchanger310 can be a composition of different materials, for instance, a material with high heat transfer properties can be used at locations where heat transfer occurs, such as theheat exchange plate316, and a different material used for other portions, such as an thermal insulating material at the external areas. This composition of materials would allow greater heat transfer and reduce potential for adverse effect such as condensation.
• The heat exchange medium flows through the heat exchanger, entering at an inlet (not shown), passing through thechamber314 and exiting by anoutlet312. Thechamber314 can be formed to direct the heat exchange medium within theheat exchanger310. For instance, thechamber314 can be formed to direct the flow so that it initially passes over the most heat producing and/or sensitive components of thedevice350. In some embodiments, the flow is directed to pass over the pin electronic dies. Thechamber314 can also include fins or similar structures to increase the surface area and aid in heat transfer.
• Positioned between the heat exchange medium in thechamber314 and the components of thedevice350 is theheat exchange plate316. To facilitate heat transfer theheat exchange plate316 can be formed to be in direct contact with the components of thedevice350. Also, the heat transfer plate can be of a material having good heat transfer characteristics, including, copper, brass, aluminum and the like. The heat transfer plate can be placed away from thedevice350, as shown, by a set offeet317, which can also act to seal the space between the heat transfer plate and thedevice350.
• Theheat exchanger318 can also includes mounts or a set ofplate ears318 for receiving thefasteners320 and allowing the heat exchanger to be secured to the rest of theunit300.
• Thefasteners320 are positioned between theheat exchanger310 and the bolsterplate330. Thefasteners320 function to urge theheat exchanger320 as a compression plate down against thedevice350, and thedevice350 into thedevice board340. Not only does this compression aid in heat transfer between the heat exchanger and thedevice350, but as further detailed below, by pressing thedevice350 into thedevice board340, electrical contact between thedevice350 and thedevice board340 can be facilitated. Thefasteners320 can be compression bolts or similar articles.
• The bolsterplate330 is positioned below the device board and functions as compression plate.
• In certain embodiments, thedevice board340 is a printed circuit board or a channel card. Thedevice board340 can function not only to hold theunit300, but it also can act supply electrical connections to thedevice350. As noted above, the device board can also be used to mount intake and exhaust manifolds (not shown) for the heat exchange system.
• Thedevice350 includes abody352, aframe353, aninterface354, afirst component356 and asecond component358. In certain embodiments thebody352 is a multichip module or MCM, where one or more chips or dies are mounted thereto. Theframe353 can function to contain theinterface354, particularly where, described below, a deformable material is used for theinterface354. In some embodiments, theinterface354 is a conductive elastomer which provides electrical connections between thedevice board340 and thebody352 including itscomponents356 and358. One such conductive elastomer is MPI available from Tyco, Inc. of Attleborough, Mass. in a Kapton film available from Tyco, Inc. of Attleborough, Mass.
• In at least one embodiment of the present invention, as the MCM is urged against the printed circuit board, by the actions of the heat exchanger and the bolster plate as compression plates and the compression bolts, the conductive elastomer is deformed and electrical connections are formed between the MCM and printed circuit board.
• In other embodiments, theinterface354 can be a set of pins or other leads extending either from thebody352 or thedevice board340 to contact either thedevice board340 or thebody352, respectfully. Such pins or leads can be secured by conventional means, such as by soldering.
• Depending on the embodiment of the present invention, thefirst component356 can include one or more pin electronics dies. Since in ATE applications pin electronics dies tend to be sensitive to temperature levels and variations thereof, at least more than other chips, such as digital ASIC chips, the pin electronics dies are typically positioned furthest upstream, relative to other chips in the MCM. That is, the pin electronics dies are positioned to be cooled first by the coolant to assure that they are cooled by the most uniform coolant. To aid in the heat transfer between the pin electronics dies and the heat exchange plate316 athermal paste357 can be applied therebetween. An example of a suitable thermal paste is ATC 3.8, which is available from IBM, Inc. of East Fishkill, N.Y.
• In certain embodiments of the present invention, thesecond component358 can be a digital ASIC chip. As noted above, since digital ASIC chips tend to be less temperature sensitive than pin electronics dies, the digital ASIC chips can be positioned downstream in the flow of the coolant from the pin electronics dies.
• In other embodiments of the present invention, thecooling plate200 ofFIG. 2 can be used as theheat exchanger310 of theintegrated unit300 ofFIG. 3. Also, theintegrated unit300 can be used in theheat exchange system100 ofFIG. 1.
• FIG. 4ashows a top cut-away view of a cooling system in accordance with at least one embodiment of the present invention.FIG. 4bshows a side cut-away view of a portion of a heat exchange system in accordance with at least one embodiment of the present invention. The embodiment shown inFIGS. 4aandbis acooling system400 that has asingle manifold405 mounted on theboard460, for cooling a set ofelectronic devices470. Thecombination manifold405 includes anintake manifold410 and anexhaust manifold450, which are separated from each other by aflow separating structure407 positioned within thecombination manifold405. The separatingstructure407 functions to divide theintake manifold410 from theexhaust manifold450, so to not allow mixing of the intake and exhaust flows of the heat transfer medium (not shown).
• Connected along thecombination manifold405 are a set of cooling plates orcold plates430 which in turn are positioned on the set ofdevices470. The manifold405 and coolingplates430 each have a set of openings that are aligned to allow the heat transfer medium to flow from theintake manifold410 through the coolingplates430 and out into theexhaust manifold450. The flow of the heat exchange medium is generally shown by the arrows D1, D2, D3, D4 and D5 inFIG. 4aand E1, E2 and E3 inFIG. 4b.
• The heat exchange medium can be any of a variety of substances including a gas or a liquid. In some embodiments the heat exchange medium is an inert liquid.
• The separatingstructure407 is shaped to direct the flow of the heat exchange medium from theintake manifold410 to thecooling plate430 and out of thecooling plate430 into theexhaust manifold450. The separatingstructure407 forms anintake passage420 which directs flow from theintake manifold410 to anopening422, which abuts anopening432 of thecooling plate430, as shown inFIG. 4b. In this manner the flow of the heat exchange medium (not shown) can move from theintake manifold410 into the intake passage, as shown generally by arrow E1, then through theopenings422 and432 into achamber434, as shown generally by arrow E2, and then over aheat transfer plate436, as shown generally by the arrow E3. SinceFIG. 4bis a cross-section, as defined inFIG. 4a, the return path and exit of the flow are not shown inFIG. 4b.
• With theopenings422 and432 positioned adjacent each other, a variety of different means and structures can be use to form a seal between theopenings422 and432. In at least one embodiment an O-ring, positioned between the combination manifold and thecooling plate430, is used. Also, a quick-disconnect connector can be used between theopenings422 and432. Such a connector can include a valve, or valves, to prevent or limit any leakage of the heat exchange medium.
• In certain embodiments, thecooling plate430 can be removed from both thecombination manifold405 and thedevice470 to allow for access to thedevice470 for servicing, repair or replacement. In some embodiments, thecooling plate430 is secured to theboard460 such that it is capable of also functioning as a lid for thedevice470 and/or a compression plate. Some of these embodiments are described above in reference toFIG. 3.
• The present invention can also be used to supply a heat exchange medium to more than one card or board by using an intake manifold and an exhaust manifold positioned at least adjacent to the set of cards, with intake and exhaust tubes connecting the manifolds to the cards. In turn, the cards can each have intake and exhaust manifolds for supplying the heat exchangers mounted thereto. This dual parallel heat exchange system provides not only consistent and predictable cooling to each of the components on a given card, but also to each of the cards in a set of cards.
• While the present invention can be used in a variety of ATE applications, the invention is also capable of being used in many other non-ATE applications as well. In at least some embodiments, the invention can be employed in applications such as servers, where, for example, 1U size boards, i.e. 1.75″ tall, have typically at least 2× processors and preferably 4×. The invention's cooling and fluid distribution allows desired modularity and flexibility in serving individual processors of such applications.
• Having described this invention in connection with a number of embodiments, modification will now certainly suggest itself to those skilled in the art. As such, the invention is not to be limited to the disclosed embodiments except as required by the appended claims.

Claims (24)

1. A heat exchange device comprising:

a) a printed circuit board;

b) a multichip module mounted on the printed circuit board;

c) a cold plate positioned on the multichip module; and

d) a bolster plate located on a side of the printed circuit board opposite the cold plate; and

e) a fastener securing the bolster plate and the cold plate with the printed circuit board, wherein the fastener urges the cold plate against the multichip module and the multichip module against the printed circuit board.

2. The heat exchange device ofclaim 1, wherein the cold plate forms a lid to the multichip module.

3. The heat exchange device ofclaim 1, wherein the multichip module further comprises a pin electronics die abutting the cold plate.

4. The heat exchange device ofclaim 3, wherein pin electronics die abut the cold plate with a thermal paste therebetween.

5. The heat exchange device ofclaim 1 further comprising a conductive elastomer positioned between the multichip module and the printed circuit board.

6. The heat exchange device ofclaim 1, wherein the multichip module further comprises at least one pin electronics die positioned within the multichip module such that the at least one pin electronics dies is cooled prior to cooling other die within the multichip module.

7. The heat exchange device ofclaim 1, wherein the bolster plate is a compression plate.

8. A heat exchange apparatus comprising:

a) at least one heat exchanger;

b) an intake manifold in fluid communication with each heat exchanger of the at least one heat exchanger, wherein the intake manifold is capable of providing a heat exchange medium separately to each heat exchanger;

c) a plurality of multichip modules mounted to a card, wherein each multichip module of the plurality of multichip modules is positioned between a heat exchanger and the card, such that heat can transfer between each multichip module and a respective heat exchanger;

d) a bolster plate positioned on a side of the card opposite the multichip modules and the at least one heat exchanger; and

e) a fastener securing the bolster plate and the at least one heat exchanger with the card, wherein the fastener secures the at least one heat exchanger with the multichip module.

9. The heat exchange apparatus ofclaim 8, wherein each multichip module abuts at least one heat exchanger.

10. The heat exchange apparatus ofclaim 9, wherein each multichip module is mounted to at least one heat exchanger.

11. The heat exchange apparatus ofclaim 9, wherein each multichip module is compression mounted to at least one heat exchanger.

12. The heat exchange apparatus ofclaim 9, wherein each multichip module further comprises a pin electronics die, and wherein the pin electronics die abuts at least one heat exchanger.

13. The heat exchange apparatus ofclaim 8, wherein each heat exchanger is a cold plate.

14. The heat exchange apparatus ofclaim 13, wherein the cold plate forms a lid to a multichip module.

15. The heat exchange apparatus ofclaim 8, wherein the heat exchange medium is an inert liquid.

16. The heat exchange apparatus ofclaim 8 further comprising a connector positioned between the intake manifold and each heat exchanger, such that each heat exchanger can be disconnected from the intake manifold.

17. The heat exchanger apparatus ofclaim 8, wherein the bolster plate is a compression plate.

18. A heat exchange apparatus comprising:

a) at least one heat exchanger;

b) an intake manifold in fluid communication with each heat exchanger of the at least one heat exchanger, wherein the intake manifold is capable of providing a heat exchange medium separately to each heat exchanger;

c) an exhaust manifold adjacent to the intake manifold, the exhaust manifold being in fluid communication with each heat exchanger of the at least one heat exchanger, wherein the exhaust manifold is capable of receiving the heat exchange medium from each heat exchanger;

d) a plurality of multichip modules mounted to a card, wherein each multichip module of the plurality of multichip modules is positioned between a heat exchanger and the card, such that heat can transfer between each multichip module and a respective heat exchanger;

e) the exhaust manifold and the intake manifold positioned above and adjacent to a side of the card; and

f) the plurality of multichip modules being mounted on the side of the card in a position lateral to the intake manifold and the exhaust manifold;

g) a bolster plate positioned on a side of the card opposite the multichip modules and the at least one heat exchanger; and

h) a fastener securing the bolster plate and the at least one heat exchanger with the card, wherein the fastener secures the at least one heat exchanger with the multichip module.

19. A heat exchange apparatus ofclaim 18, wherein the cold plate forms a lid to the multichip module.

20. The heat exchange apparatus ofclaim 18, wherein the multichip module further comprises a pin electronics die abutting the cold plate.

21. The heat exchange apparatus ofclaim 18, wherein pin electronics die abut the cold plate with a thermal paste therebetween.

22. The heat exchange apparatus ofclaim 18 further comprising a conductive elastomer positioned between the multichip module and the printed circuit board.

23. The heat exchange apparatus ofclaim 18, wherein the bolster plate is a compression plate.

24. The heat exchange apparatus ofclaim 18 further comprising a connector positioned between the intake manifold and each heat exchanger, further comprising a connector positioned between the exhaust manifold and each heat exchanger, such that each heat exchanger can be disconnected from the intake manifold and the exhaust manifold.

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