Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K7/00—Constructional details common to different types of electric apparatus
  • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
  • H05K7/20709—Modifications to facilitate cooling, ventilating, or heating for server racks or cabinets; for data centers, e.g. 19-inch computer racks
  • H05K7/20763—Liquid cooling without phase change
  • H05K7/20781—Liquid cooling without phase change within cabinets for removing heat from server blades
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K7/00—Constructional details common to different types of electric apparatus
  • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
  • H05K7/20709—Modifications to facilitate cooling, ventilating, or heating for server racks or cabinets; for data centers, e.g. 19-inch computer racks
  • H05K7/20718—Forced ventilation of a gaseous coolant
  • H05K7/20727—Forced ventilation of a gaseous coolant within server blades for removing heat from heat source
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K7/00—Constructional details common to different types of electric apparatus
  • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
  • H05K7/20709—Modifications to facilitate cooling, ventilating, or heating for server racks or cabinets; for data centers, e.g. 19-inch computer racks
  • H05K7/20763—Liquid cooling without phase change
  • H05K7/20772—Liquid cooling without phase change within server blades for removing heat from heat source
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/0001—Technical content checked by a classifier
  • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Definitions

• the invention relates to a mounting mechanism in general, and specifically, to a mounting mechanism to form a thermal interface between two heat exchanging devices.
• Cooling of high performance integrated circuits with high heat dissipation is presenting significant challenge in the electronics cooling arena.
• Conventional cooling with heat pipes and fan mounted heat sinks are not adequate for cooling chips with every increasing wattage requirements, including those exceeding 10OW.
• Electronics servers such as blade servers and rack servers, are being used in increasing numbers due to the higher processor performance per unit volume one can achieve.
• the high density of integrated circuits also leads to high thermal density, which is beyond the capability of conventional air-cooling methods.
• a particular problem with cooling integrated circuits on electronics servers is that multiple electronics servers are typically mounted in close quarters within a server chassis.
• electronics servers are separated by a limited amount of space, thereby reducing the dimensions within which to provide an adequate cooling solution.
• stacking of electronics servers does not provide the mounting of large fans and heat sinks for each electronics server.
• electronics server stacks within a single server chassis are cooled by one large fan, a heat sink or both.
• the integrated circuits on each electronics server are cooled using the heat sink and the large fan that blows air over the heat sink, or simply by blowing air directly over the electronics servers.
• the amount of air available for cooling the integrated circuits is limited.
• Liquid cooling systems such as closed-loop liquid cooling systems and heat pipes, present alternative methodologies for conventional cooling solutions. Liquid cooling needs to occur at the integrated circuit level on a electronics server. Due to the density of the electronics and the high power densities of ultra high performance servers, the heat picked up by a liquid cooling loop cannot be effectively discharged to the air via a radiator, as is common practice in other form factors such as desktops and work stations. The heat must be transferred to the server rack cooling system, which may be comprised of a pumped refrigerant or chilled water loop. A key requirement of servers is the ability to swap in and out electronics servers. As such, there is a need to effectively connect and disconnect each electronics server and its corresponding cooling system to and from the rack cooling system.
• Cooling systems of the present invention are directed to cooling solutions used to transfer heat produced by one or more heat generating devices, such as microprocessors or other integrated circuits, from one or more electronics servers to the ambient.
• a liquid-based cooling system is used.
• a server chassis is configured to house multiple electronics servers. Examples of electronics servers includes, but are not limited to, blade servers and rack servers. Each electronics server is coupled to a backplane or mid- plane within the server chassis. For purposes of this disclosure, the terms “backplane” and “mid-plane” are used interchangeably.
• Each electronics server includes one or more heat generating devices.
• Each liquid based cooling system includes a server pump and one or more microchannel cold plates (MCP). Fluid lines preferably couple the MCPs and the server pump. In other embodiments, heat pipes or conduction means are used instead of the liquid-based cooling system.
• MCP microchannel cold plates
• the liquid based cooling system for each electronics server includes a rejector plate.
• Each rejector plate is configured with fluid channels, preferably micro-channels. Alternatively, each rejector plate is configured with macro-channels.
• the micro-channels are coupled to the fluid lines thereby forming a first closed loop including the MCPs, the server pump and the rejector plate.
• the rejector plate is coupled to a chassis cold plate via a thermal interface material, thereby forming a thermal interface.
• the thermal interface is configured along a plane that is non-perpendicular to an insertion vector of the electronics server into a server rack chassis. In some embodiments, the thermal interface plane is parallel to the insertion vector.
• the rejector plates for each of the electronics servers are coupled to the chassis cold plate in this manner.
• the chassis cold plate is coupled to the server chassis.
• the chassis cold plate includes one or more heat exchanging elements.
• the chassis cold plate includes fluid channels which are coupled via fluid lines to a liquid-to-air heat exchanging system.
• the liquid-to-air heat exchanging system includes a heat rejector, one or more fans, and an external pump.
• the chassis cold plate, the heat rejector, the external pump, and fluid lines connected thereto form a second closed loop.
• Fluid is pumped through the first closed loop such that heat generated by each heat generating device on the electronics server is transferred to the fluid flowing through each respective MCP coupled to the heat generating devices.
• the heated fluid flows into the fluid channels within the rejector plate.
• fluid is pumped through the fluid channels in the chassis cold plate by the external pump. Heat within the fluid flowing through each rejector plate is transferred through a thermal interface to the chassis cold plate and to the fluid flowing through the chassis cold plate. Heated fluid within the chassis cold plate is pumped to the heat rejector within the liquid-to-air heat exchanging system, where heat is transferred from the fluid to the air.
• Fluid flowing in the first closed loop system is independent of fluid flowing in the second closed loop system.
• TIM thermal interface material
• Methods for applying pressure include, but are not limited to, mechanical clamping, springs, electro-mechanical motors or actuators, pneumatics and hydraulics.
• the heat exchangers can take a variety of shapes, including planar, cylindrical, curvilinear, or other non-planar confiugrations.
• the mating surfaces of the heat exchangers can be smooth or with physical features such as mating teeth to increase surface area or ensure alignment.
• Thermal contact can be made on one or more surfaces creating a sandwich type structure.
• a heat exchanger can be a single solid piece or can be made up of an array of smaller heat exchangers to allow flexibility when mating curved to curved surfaces.
• the mounting mechanism used to engage and disengage the heat exchangers is configured to isolate the force applied to the two heat exchangers.
• the mounting mechanism includes an interlocking channel mechanism that prevents transfer of the applied force to the rest of the electronics server or rack chassis. Without isolating this force, the force applied to the electronics server may result in disconnecting the electrical connections between the electronics server and the rack, as well as providing mechanical stress to the electronics server and the rack chassis.
• the mounting mechanism can be coupled to the electronics server locking mechanism such that the action of locking the electronics server into the server rack causes the heat exchangers to engage in thermal contact. This is a fail safe procedure since no separate process is required to engage the electronics server cooling loop.
• unlocking the electronics server causes the heat exchangers to disengage allowing the electronics to be removed without interference from either the electronics server cooling loop or the rack cooling loop.
• Figure 1 illustrates a perspective view of an exemplary cooling system according to the first embodiment of the present invention.
• Figure 2 illustrates a side view of the nth electronics server coupled to the liquid-to- air heat exchanging system.
• Figure 3 illustrates a side view of an exemplary cooling system according to a second embodiment of the present invention.
• Figure 4 illustrates an exemplary heat transfer configuration between a mating surface of the rejector plate and a mating surface of the chassis cold plate.
• Figure 5 illustrates a side view of an exemplary cooling system according to the third embodiment of the present invention.
• Figure 6 illustrates a side view of a first mounting assembly used to couple a electronics server to a server rack to form a thermal interface.
• Figure 7 illustrates a cut-out side view of the mounting assembly from Figure 6 in an engaged configuration.
• Figure 8 illustrates a cut-out side view of the mounting assembly from Figure 6 in a disengaged configuration.
• Figure 9 illustrates a side view of a second mounting assembly used to couple a electronics server to a server rack to form a thermal interface.
• Figure 10 illustrates a cut-out side view of the mounting assembly from Figure 9 in an engaged configuration.
• Figure 11 illustrates a cut-out side view of the mounting assembly from Figure 9 in a disengaged configuration.
• Figure 12 illustrates a perspective view of the of the rejector plate and the chassis cold plate within the mounting assembly of Figures 9-11.
• Figure 13A illustrates a perspective view of a first embodiment of a horizontal cam configuration.
• Figure 13B illustrates a side view of the first embodiment of the horizontal cam configuration of Figure 13A.
• Figure 14A illustrates a perspective view of a second embodiment of a horizontal cam configuration.
• Figure 14B illustrates a side view of the second embodiment of the horizontal cam configuration of Figure 14A.
• Figure 15 A illustrates a perspective view of a first embodiment of a vertical cam configuration.
• Figure 15B illustrates a top down view of the first embodiment of the vertical cam configuration of Figure 15 A.
• Figure 16A illustrates a perspective view of a second embodiment of a vertical cam configuration.
• Figure 16B illustrates a top down view of the second embodiment of the vertical cam configuration of Figure 16A.
• Figure 17 illustrates a top down view of a first ramp translation mechanism.
• Figure 18 illustrates a top down view of a second ramp translation mechanism.
• Figure 19 illustrates a top down view of a scissor jack translation mechanism.
• Figure 2OA illustrates a top down view of an exemplary embodiment of the translation mechanism using cams, slots, and pins in a disengaged position.
• Figure 2OB illustrates a top down view of the translation mechanism of Figure 20A in an engaged position.
• Figure 21 A illustrates a top down view of an exemplary embodiment of the translation mechanism using slots and pins in a disengaged position.
• Figure 21B illustrates a top down view of the translation mechanism of Figure 21 A in an engaged position.
• Figure 21C illustrates a side view of the exemplary translation mechanism of Figure
• Figure 22 illustrates an alternative configuration of the chassis cold plate and rejector plate.
• Embodiments of the present invention are directed to a cooling system that transfers heat generated by one or more heat generating devices on a electronics server to a liquid-to- air heat exchanging system.
• the cooling system described herein can be applied to any electronics sub-system that is mounted to a backplane, including but not limited to, a blade server and a rack server.
• a server chassis is configured to house multiple electronics servers. Each electronics server is coupled to a backplane or mid-plane within the server chassis.
• Each electronics server includes one or more processors as is well known in the art.
• the cooling system is a liquid-based cooling system.
• Each liquid-based cooling system includes a server pump and one or more microchannel cold plates (MCP).
• MCP microchannel cold plates
• each liquid- based cooling system is configured with one MCP for each heat generating device on the electronics server.
• the MCPs and the server pump are preferably mounted to the electronics server. Fluid lines couple the MCPs and the server pump.
• any means for transporting fluid within a sealed environment can be used.
• the server pump is any conventional pump, including, but not limited to, an electro-osmotic pump and a mechanical pump.
• heat pipes or conduction means are used instead of the liquid- based cooling system.
• the liquid based cooling system for each electronics server includes a rejector plate.
• the fluid lines coupling the MCPs and the server pump are also coupled to the rejector plate with fluid channels configured therein.
• the MCPs, the server pump, the rejector plate, and the fluid lines connected thereto form a first closed loop.
• Each server chassis includes at least one chassis cold plate.
• the rejector plate is coupled to the chassis cold plate via a thermal interface material.
• the rejector plates for each of the electronics servers are coupled to the chassis cold plate in this manner such that all rejector plates, and therefore the cooling system for each electronics server, are coupled to the chassis cold plate.
• Each electronics server is installed into a backplane along an insertion vector.
• the thermal interface between the rejector plate of the electronics server and the chassis cold plate is formed along a non-perpendicular plane relative to the insertion vector. In some embodiments, the thermal interface plane is parallel to the insertion vector.
• a mounting mechanism is used.
• the chassis cold plate includes fluid channels which are coupled via fluid lines to a liquid-to-air heat exchanging system.
• the liquid-to-air heat exchanging system includes a heat rejector, one or more fans, and an external pump. Fluid lines couple the chassis cold plate to the heat rejector, the heat rejector to the external pump, and the external pump to the chassis cold plate.
• the chassis cold plate, the heat rejector, the external pump, and the fluid lines connected thereto foim a second closed loop.
• At least one blowing fan is preferably included to generate airflow over the surface of the heat rejector.
• the heat rejector is preferably a counter flow radiator.
• the entire chassis cold plate and the liquid-to-air heat exchanging system is included within a single enclosure, such as the server housing. In other embodiments, a portion of the chassis cold plate extends external to the server housing and the liquid-to-air heat exchanging system is remotely located to the server housing.
• fluid is pumped through the fluid lines and the MCPs by the server pump such that heat generated by each heat generating device on the electronics server is transferred to the fluid flowing through each respective MCP coupled to the heat generating devices. Heat is transferred from the heat generating devices to the fluid flowing through the MCPs, and the heated fluid flows into the fluid channels within the rejector plate.
• fluid is pumped through the fluid channels in the chassis cold plate by the external pump. Thermal characteristics of the rejector plate, the chassis cold plate, and the thermal interface material between the rejector plate and the chassis cold plate are configured such that heat within the fluid flowing through each rejector plate is transferred to the fluid flowing through the chassis cold plate.
• Heated fluid within the chassis cold plate is pumped to the heat rejector within the liquid-to-air heat exchanging system, where heat is transferred from the fluid to the air.
• the cooled fluid exits the liquid-to-air heat exchanging system and is pumped back to the chassis cold plate.
• FIG. 1 illustrates a perspective view of an exemplary cooling system 10 according to the first embodiment of the present invention.
• the cooling system 10 includes a chassis housing 12 for housing a back plane 20, a chassis cold plate 60, and a liquid-to-air heat exchanging system 70.
• the cooling system 10 is configured to cool up to N electronics servers.
• a first electronics server 30, a second electronics server 32, and an nth electronics server 34 are each mounted and electronically coupled to the back plane 20.
• each electronics server 30, 32, 34 includes two processors. It is understood that each electronics server can be configured independently and that each electronics server can include more or less than two processors.
• each electronics server 30, 32, 34 is a liquid based cooling system that includes at least one server pump 40, an MCP 42, an MCP 44, and a rejector plate 50.
• the liquid based cooling system includes one MCP for each processor on the corresponding electronics server.
• each liquid based cooling system includes two corresponding MCPs, preferably one per processor.
• the server pump 40 is a mechanical pump.
• the server pump 40 is a mechanical pump.
• each MCP 42, 44 is a fluid-based, micro- channel heat exchanger of the type described in U.S. Patent No. 7,000,684, which is hereby incorporated by reference.
• the rejector plate 50 is configured with micro-channels that maximize a surface area exposed to a fluid passing therethrough.
• a bottom surface of the rejector plate 50 is thermally coupled to a top surface of the chassis cold plate 60.
• the rejector plate 50 for each electronics server 30, 32, 34 is thermally coupled to the chassis cold plate 60.
• the chassis plate 60 is preferably configured with micro-channels that maximize a surface area exposed to a fluid passing there through.
• Each of the electronics servers 30, 32, 34 is coupled to the backplane 20 along an insertion vector.
• the insertion vector is perpendicular to the backplane 20.
• a thermal interface between the rejector plate 50 and the chassis cold plate 60 isrformed along a non- perpendicular plane relative to the insertion vector. In some embodiments, the thermal interface plane is parallel to the insertion vector.
• the liquid-to-air heat exchanging system 70 includes an external pump 72, a heat rejector 74, and a fan 76.
• the external pump 72 and the heat rejector 74 are coupled to the chassis cold plate 60.
• the external pump 72 is a mechanical pump.
• the external pump 72 is an electro-osmotic pump.
• the heat rejector 74 is preferably a radiator with micro-channels and fins positioned closely together. More preferably, the heat rejector 74 is a counter flow radiator of the type described in U.S. Patent No. 6,988,535, which is hereby incorporated by reference.
• the fan 76 comprises one or more blowing fans for generating air flow across and/or through the heat rejector 74.
• Figure 2 illustrates a side view of the nth electronics server 34 coupled to the liquid- to-air heat exchanging system 70.
• the server pump 40 is coupled to the MCP 42 by one or more fluid lines 46.
• the MCP 42 is coupled to the MCP 44 by one or more fluid lines 46.
• the MCP 44 is coupled to the rejector plate 50 by one or more fluid lines 46.
• the rejector plate 50 is coupled to the server pump 40 by one or more fluid lines 46.
• the fluid lines 46 are metallic or non-metallic.
• each MCP within a given liquid based cooling system can be configured in parallel such that fluid reaching any of the MCPs has not previously passed through, and been heated by, another MCP. In this manner, fluid reaching any MCP configured in parallel is cooler than if the fluid first passes through a serially connected MCP.
• the server pump 40 is coupled to the MCP 42 by one or more fluid lines 46, and separate fluid lines couple the server pump 40 to the MCP 44.
• one or more fluid lines couple the MCP 42 to the rejector plate 50 and one or more fluid lines couple the MCP 44 to the rejector plate 50.
• the one or more fluid lines leaving the MCP 42 and the one or more fluid lines leaving the MCP 44 are joined prior to coupling with the rejector plate 50.
• multiple MCPs are configured in any combination of series and parallel configurations.
• the MCP 42, the MCP 44, the rejector plate 50, the server pump 40, and the fluid lines 46 form a first closed loop through which fluid flows.
• a function of the liquid-based cooling system of Figure 2, which includes the first closed loop, is to capture heat generated by the two processors (not shown) on the electronics server 34.
• the MCP 42 is thermally coupled to a first processor on the electronics server 34.
• the MCP 44 is thermally coupled to a second processor on the electronics server 34.
• heat from the first processor is transferred to the fluid.
• heat from the second processor is transferred to the fluid.
• the type of fluid used in the liquid-based cooling system is preferably water-based.
• the fluid within the liquid-based cooling system is based on combinations of organic solutions, including but not limited to propylene glycol, ethanol and isopropanol (IPA). Still alternatively, the fluid within the liquid-based cooling system is a pumped refrigerant.
• the fluid used in the liquid-based cooling system also preferably exhibits a low freezing temperature and has anti-corrosive characteristics.
• the fluid exhibits single phase flow while circulating within the liquid- based cooling system.
• the fluid is heated to a temperature to exhibit two phase flow, wherein the fluid undergoes a phase transition from liquid to a vapor or liquid/vapor mix.
• the heated fluid flows from the MCPs 42, 44 into the micro-channels within the rejector plate 50. Heat is transferred from the heated fluid within the micro-channels to the material of the rejector plate 50.
• a thermal interface material 62 provides efficient heat transfer between the rejector plate 50 and the chassis cold plate 60 so that heat from the rejector plate 50 is transferred to the material of the chassis cold plate 60.
• the thermal interface material 62 is preferably a compliant material such as thermal grease, solder, or any type of thermally conducting gap filling material.
• the chassis cold plate 60 is coupled to the external pump 72 by one or more fluid lines 64.
• the chassis cold plate 60 is coupled to the heat rejector 74 by one or more fluid lines 64.
• the heat rejector 74 is coupled to the external pump 72 by one or more fluid lines 64.
• the fluid lines 64 are metallic or non-metallic.
• the chassis cold plate 60, the heat rejector 74, the external pump 72, and the fluid lines 64 form a second closed loop through which fluid flows.
• the fluid in second closed loop preferably comprise the same type of fluid discussed above in relation to the first closed loop.
• the fluid in the second closed loop is independent of the fluid in the first closed loop.
• a function of the second closed loop and the liquid-to-air heat exchanging system 70 is to transfer heat from the chassis cold plate 60 to the ambient.
• heat from material of the chassis cold plate 60 is transferred to the fluid.
• the heated fluid flows to the heat rejector 74.
• heat rejector 74 heat is transferred from the fluid to the material of the heat rejector 74.
• the fan 76 blows air over the surface of the heat rejector 74 such that heat is transferred from the heat rejector 74 to the ambient.
• the chassis 12 ( Figure 1) includes intake vents and exhaust vents through which air enters and leaves the cooling system 10 ( Figure 1). Cooled fluid leaving the heat rejector 74 flows back to the chassis cold plate 60.
• FIG 3 illustrates a side view of an exemplary cooling system according to a second embodiment of the present invention.
• the cooling system 110 can be identical to the cooling system 10 of Figure 1 with the exception that the liquid-to-air heat exchanging system 70 (Figure 1) of cooling system 10 is replaced by an external water supply 170.
• the external water supply 170 represents a continuous running water supply, such as the public water supply provided to most commercial and residential facilities. Alternatively, the external water supply 170 represents an external source of any type of fluid to which heat is transferred.
• fresh water from the external water supply 170 flows to the chassis cold plate 60. Heat from the chassis cold plate 60 is transferred to the water in the same manner as that described in relation to cooling system 10 ( Figure 1).
• the heated water flows from the chassis cold plate 60 to the external water supply 170, where the heated water is disposed. Pressure from the water entering the fluid lines 64 from the external water supply 170 is sufficient to circulate the water through the chassis cold plate 60 and back to the external water supply for disposal.
• an external pump is coupled to the fluid lines 64 between the external water supply 170 and the chassis cold plate 60 to pump the water to the chassis cold plate 60.
• the chassis cold plate is modified with quick connects and the rejector plate is removed from each electronics server such that the fluid lines within the liquid based cooling system of each electronics server are coupled directly to the micro- channels within the chassis cold plate via the quick connects.
• the fluid lines within each liquid based cooling system are modified with appropriate fittings to couple with the quick connects on the chassis cold plate.
• the quick connects are configured onto the fluid lines of the liquid based cooling system, and the chassis cold plate is configured with appropriate fittings to couple with the quick connects on each electronics server.
• FIG. 5 illustrates a side view of an exemplary cooling system 210 according to the third embodiment of the present invention.
• cooling system 210 is shown in Figure 5 as including only a single electronics server 134, it is understood that the cooling system 210 also includes a chassis housing (not shown) and a back plane (not shown) configured to hold up to N electronics servers in a manner similar to that described in relation to cooling system 10 in Figure 1.
• each electronics server within the cooling system 210 is described as including two processors. It is again understood that each electronics server in the cooling system 210 can be configured independently and that each electronics server can include more or less than two heat generating devices, such as processors.
• a liquid based cooling system is coupled to the electronics server 134.
• the liquid based cooling system includes an MCP 142 and an MCP 144 coupled together via one or more fluid lines 146.
• the liquid based cooling system includes one MCP coupled to each processor on the electronics server 134.
• Each MCP 142, 144 is functionally equivalent to the MCPs 42, 44 ( Figures- 1-3)
• the cooling system 210 includes the liquid-to-air heat exchanging system 70 coupled to a chassis cold plate 160 via one or more fluid lines 164.
• the chassis cold plate 160 is configured with micro-channels that enhance a surface area exposed to a fluid passing there through.
• the chassis cold plate 160 is also configured with quick connects 170 and 172.
• the fluid lines 146 are configured with appropriate fittings to couple with the quick connects 170 and 172.
• the fluid lines 146 are coupled directly to the micro- channels of the chassis cold plate 160 via the quick connects 170, 172.
• the liquid based cooling system coupled to electronics server 134, the chassis cold plate 160, the heat rejector 74, the external pump 72, and the fluid lines 164 form a single closed loop. Within this closed loop, the fluid is pumped by the external pump 72.
• the type of fluid used in the cooling system of the third embodiment is the same type of fluid used in the cooling system 10 of the first embodiment.
• Figure 5 shows a single quick connect 170 through which fluid flows from the chassis cold plate 160 to the fluid lines 146
• the quick connect 170 is representative of one or more physical quick connects through which fluid flows from the micro-channels in the chassis cold plate 160 to the one or more fluid lines 146.
• Figure 5 shows a single quick connect 172 through which fluid flows from the fluid lines 146 to the chassis cold plate 160
• the quick connect 172 is representative of one or more physical quick connects through which fluid flows from the one or more fluid lines 146 to the micro- channels in the chassis cold plate 160.
• each MCP within a given liquid based cooling system is configured in parallel.
• the quick connects 170 are coupled to the MCP 142 by one or more fluid lines 146, and separate fluid lines couple the quick connects 170 to the MCP 144.
• one or more fluid lines couple the MCP 142 to the quick connects 172 and one or more fluid lines couple the MCP 144 to the quick connects 172.
• the MCP 142 is thermally coupled to a first processor on the electronics server 134.
• the MCP 144 is thermally coupled to a second processor on the electronics server 134.
• heat from the first processor is transferred to the fluid.
• heat from the second processor is transferred to the fluid.
• the heated fluid flows from the fluid lines 146 into the micro-channels within the chassis cold plate 160 via the quick connect 172.
• the chassis cold plate 160 is coupled to the external pump 72 by one or more fluid lines 164.
• the chassis cold plate 160 is coupled to the heat rejector 74 by one or more fluid lines 164.
• the heated fluid in the micro-channels of the chassis cold plate 160 flows to the heat rejector 74 via fluid lines 164.
• the fluid lines 164 are metallic or non-metallic.
• a function of the liquid-to-air heat exchanging system 70 is to transfer heat from a fluid to the ambient.
• heat is transferred from the fluid to the material of the heat rejector 74.
• the fan 76 blows air over the outer surface of the heat rejector such that heat is transferred from the heat rejector 74 to the ambient.
• Cooled fluid leaving the heat rejector 74 flows back to the chassis cold plate 160 via fluid lines 164.
• the cooled fluid flows through the chassis cold plate 160 to the fluid lines 146 via the quick connect 170.
• the cooled fluid flows to the MCPs 142 and 144.
• the present cooling system is not limited to the components shown in Figure 1-5 and alternatively includes other components and devices.
• the cooling system 10 can also include a fluid reservoir coupled to either the closed loop of the liquid based cooling system, the closed loop of the chassis cold plate 60, the heat rejector 74, the external pump 72, and the fluid lines 64, or both closed loops.
• the fluid reservoir accounts for fluid loss over time due to permeation.
• the length scales of features in an efficient heat exchanger used to transfer heat from a processor are measured in microns.
• Chilled water lines can have scale and other particulate which may not be an issue at rack level cooling but can quickly clog a heat exchanger at the board level.
• Another consideration is that the level of control of materials used for larger scale cooling applications is also different then that for a electronics server cooling loop and corrosion may become an issue. For the independent cooling loop systems described above in relation to Figures 2 and 3, these considerations are eliminated.
• TIM thermal interface material
• thermal grease thermal grease
• thermal pad a thermal interface material
• pressure is applied between the two heat exchangers, the rejector plate and the chassis cold plate.
• the pressure required to hold the heat exchangers can be 20-30 psi or higher.
• Methods for*applying pressure include, but are not limited to, mechanical clamping, springs, electro-mechanical motors or actuators, pneumatics and hydraulics.
• the heat exchangers can take a variety of shapes, including planar, cylindrical, curvilinear, or other non-planar configurations.
• the mating surfaces of the heat exchangers can be smooth or with physical features such as mating teeth to increase surface area or ensure alignment.
• Thermal contact can be made on one or more surfaces creating a sandwich type structure.
• a heat exchanger can be a single solid piece or can be made up of an array of smaller heat exchangers to allow flexibility when mating non-planar surfaces.
• the mounting mechanism used to engage and disengage the heat exchangers is configured to isolate the force applied to the two heat exchangers.
• the mounting mechanism includes an interlocking mechanism that prevents transfer of the applied force to the rest of the electronics server or rack chassis. Without isolating this force, the force is applied to the electronics server and/or the rack chassis, possibly disconnecting the electrical connections between the electronics server and the rack, as well as providing mechanical stress to the electronics server and/or the rack chassis.
• the mounting mechanism can also be coupled to the electronics server locking mechanism such that the action of locking the electronics server into the rack causes the heat exchangers to engage in thermal contact. This is a fail safe procedure since no separate process is required to engage the electronics server cooling loop. Similarly, unlocking the electronics server causes the heat exchangers to disengage allowing the electronics to be removed without interference from either the electronics server cooling loop or the rack cooling loop.
• Figure 4 illustrates an embodiment of a heat transfer configuration between a mating surface of the rejector plate 50 and a mating surface of the chassis cold plate 60 coupled together via the thermal interface material 62.
• the two mating surfaces of the rejector plate 50 and the chassis cold plate 60 are configured as wedges.
• a thick portion of the rejector plate wedge 50 is aligned with a thin portion of the
• Each of the rejector plate wedge 50 and the chassis cold plate wedge 60 include channeled features to enable efficient heat transfer from the flowing fluid of the first closed loop, to the wedge interface, the flowing fluid of the second closed loop.
• the rejector plate 50 and the chassis cold plate 60 are configured using dimensions and shapes
• a mounting assembly 66 secures the rejector plate wedge 50 to the chassis cold plate 60.
• the mounting assembly 66 can include clips, screw, or any other conventional retention mechanism.
• FIGS. 6-8 illustrate one embodiment of a mounting assembly used to engage each
• the thermal interface between the two heat exchangers, the rejector plate of the electronics server and the chassis cold plate of the rack is formed by sufficiently forcing the rejector plate against the chassis cold plate, via the thermal interface material, such as TIM 62 ( Figure 4).
• TIM 62 Figure 4
• the mounting assembly contains the force thus preventing strain from being transferred to the electrical connection on the back plane of the rack or to the components within the electronics server or rack chassis.
• On the rack side there is an extruded rack channel, attached to the rack.
• the rack channel is used as part of the electronics server guide mechanism on the rack. Seated within the rack channel is the rack
• the chassis cold plate Attached to a side of the electronics server chassis is a complementary extruded structure, referred to as a chassis guide, which is configured to slide into the rack side rack channel.
• a chassis guide held within the chassis guide is the electronics server rejector plate and one or more springs.
• the rejector plate is held in a recessed position via a retracting mechanism.
• FIG. 5 illustrates a side view of the mounting assembly used to couple
• FIG. 7 illustrates a cut-out side view of the mounting assembly from Figure 6 in an engaged configuration.
• Figure 8 illustrates a cut-out side view of the mounting assembly from Figure 6 in a disengaged configuration.
• the views shown in Figures 6-8 do not show the entire electronics server 34 ( Figure 2), instead, only a portion of a electronics server chassis 36, the inlet and outlet fluid
• a chassis guide 52 is configured to extend through a side of the electronics server chassis 36.
• the chassis guide 52 is also configured to house the rejector plate 50 and springs 80.
• a rack channel 14 is coupled to the rack (not shown) and is configured around the chassis cold plate 60.
• the rack channel 14 includes extrusions 16, and the chassis guide 52 includes extrusions 54. The extrusions 16 and the
• extrusions 54 are configured to dovetail with each other to form an interlocking channel.
• the force applied to the rejector plate 50 and the chassis cold plate 60 by the springs 80 is applied within the rack channel 14 and the chassis guide 52. Because the extrusions 54 are free- floating relative to the electronics server chassis 36, the force is constrained within the mounting assembly, and the force is not transferred outside the assembly to the electronics
• the chassis guide 52 is floating relative to the electronics server chassis 36, configured as a float area 56 ( Figure 7) between the interlocking channel and the electronics server chassis 36.
• the float area 56 enables movement of the chassis guide 52 relative to the electronics server chassis 36. This clearance is used to enable the chassis guide 52 to be
• FIG. 7 illustrates the mounting assembly while the retracting mechanism is engaged.
• the mounting assembly is disengaged and the rejector plate 50 is not thermally coupled to the chassis cold plate 60.
• the interlocking channel in turn constrains the force within the mounting assembly.
• the float area 56 takes up whatever small movement of the mounting assembly must occur for this expansion, and therefore the formation of the interlocking channel, to occur. In this manner, the float area 56 enables the chassis guide 52 to slide into the rack channel 14 during installation, and then application of the force to press together the rejector plate 50 and the
• a float area can be configured at a position other than between the electronics server chassis and the rack channel.
• a float area can be positioned between the rack chassis and the rack channel on the rack side of the mounting assembly.
• a float is positioned somewhere in the mounting assembly to enable clearance
• FIGS 9-11 illustrate another embodiment of a mounting assembly used to engage each electronics server to the server rack.
• the mounting assembly shown in Figures 9-11 is similar to that of the mounting assembly of Figures 6-8 except that the rack side rack channel
• chassis cold plate is held in place by shoulder screws from behind so that the springs are pre-loaded.
• Figure 9 illustrates a side view of the mounting assembly used to couple a electronics server to a server rack to form a thermal interface.
• Figure 10 illustrates a cutout side view of the mounting assembly from Figure 9 in an engaged configuration.
• Figure 11 illustrates a cut-out side view of the mounting assembly from Figure 9 in a disengaged configuration.
• a chassis guide 152 is configured to extend through a side of the electronics
• the chassis guide 152 is also configured to house the rejector plate 50.
• a rack channel 114 is coupled to the rack (not shown).
• the rack channel 114 is configured to house the chassis cold plate 60 and springs 180.
• the rack channel 114 includes extrusions 116, and the chassis guide 152 includes extrusions 154.
• the extrusions 116 and the extrusions 154 are configured to dovetail with each other to form an interlocking channel.
• the chassis guide 152 is floating relative to the electronics server chassis 36, configured as a float area 156 ( Figure 10) between the interlocking channel and the electronics server chassis 36.
• the float area 156 enables movement of the chassis guide 152 relative to the electronics server chassis 36. This clearance is used to enable the chassis guide 152 to be loaded into the rack channel 114 as the electronics server 34 is installed in
• the chassis cold plate 60 is held in place by shoulder screws (not shown) from behind so that the springs are pre-loaded. In this manner, the chassis cold plate 60 maintains a fixed,
• a translation mechanism forces the rejector plate 50 towards and against the chassis cold plate 50, via the intervening THVl 62, as shown in Figure 10. The last portion of movement by the rejector plate 50 causes the springs 180 to compress
• FIG. 10 illustrates the thermal interface between the rejector plate 50 and the chassis clod plate 60.
• Figure 11 illustrates the mounting assembly while the translation mechanism is disengaged.
• the chassis cold plate 50 is positioned at its un-actuated position and the rejector plate 50 is not forced by the translation mechanism. As such, the rejector plate 50 is not thermally coupled to the chassis
• any conventional means can be used, including but not limited to alternative spring means, pneumatics, mechanical clamping, and hydraulics.
• Any number of translation mechanisms can be employed to create the necessary translation of the rejector plate and the chassis cold plate for full engagement.
• One method is through the use of horizontal or vertical cams. These allow the conversion of a rotational motion to a linear motion.
• the cams can be further attached to a linear mechanical linkage providing the conversion of a motion in the X direction to a motion in the Y axis.
• the shape of the cams can be custom tailored to allow for different styles of translation. For example, if identically shaped cams are used, the rejector plate is uniformly moved in parallel relative to the side of the chassis cold plate. If slightly different shaped cams are used, a progressive motion is made such that one edge of the rejector plate moves forward toward the chassis cold plate, then the other edge of the rejector plate moves. This is useful when disengaging the system and trying to break free a TIM joint.
• Figure 12 illustrates a perspective view of the of the rejector plate and the chassis cold plate within the mounting assembly of Figures 9-11.
• the rejector plate 50 is moved in the horizontal direction. Moving the rejector plate 50 from right to left engages the thermal interface. Moving the rejector plate 50 from left to right disengages the thermal interface.
• One or more cams can be coupled to a back surface 51 of the rejector plate 50.
• Figure 13A illustrates a perspective view of a first embodiment of a horizontal cam configuration. Multiple cams 202 are positioned horizontally against the back surface 51. The cams 202 are coupled via a linkage 204. Multiple cams 206 are positioned horizontally against the back surface 51. The cams 206 are coupled via a linkage 208.
• Figure 13B illustrates a side view of the first embodiment of the horizontal cam configuration of Figure 13A.
• the shape of the cams 202 and 206 determine translation of the rejector plate 50 from side to side or from top to bottom.
• the shape and orientation of the cams 202 relative to the cams 206 determines the translation of the top side of the rejector plate 50 relative to the bottom side. If the cams 202 and the cams 206 are shaped and oriented the same, then the entire rejector plate 50 moves uniformly. If the cams 202 and the cams 206 are not shaped or oriented the same, then one side of the rejector plate 50 moves differently than the other side. It is understood that more than two cams 202 can be used and/or more than two cams 206 can be used. It is also understood that more than two rows of cams can be used.
• Figure 14A illustrates a perspective view of a second embodiment of a horizontal cam configuration.
• Multiple cams 210 are positioned horizontally against the middle of the back surface 51.
• the cams 210 are coupled via a linkage 212.
• Figure 14B illustrates a side view of the second embodiment of the horizontal cam configuration of Figure 14A.
• the shape of the cams 210 determine translation of the rejector plate 50.
• the shape and orientation of each of the cams 210 relative to each other determines the translation of the side portion of the rejector plate 50 relative to the other side. If the cams 210 are each shaped and oriented the same, then the entire rejector plate 50 moves uniformly. If the cams 210 are not shaped or oriented the same, then one side of the rejector plate 50 moves differently than the other side. It is understood that more than two cams 210 can be used.
• Figure 15A illustrates a perspective view of a first embodiment of a vertical cam configuration. Multiple cams 214 are positioned vertically against the back surface 51.
• Figure 15B illustrates a top down view of the first embodiment of the vertical cam configuration of Figure 15 A.
• the shape of the cams 214 determine translation of the rejector plate 50 from side to side.
• the shape and orientation of each of the cams 214 determines the translation of one side of the rejector plate 50 relative to the other side. If the cams 214 are shaped and oriented the same, then the entire rejector plate 50 moves uniformly. If the cams 214 are not shaped or oriented the same, then one side of the rejector plate 50 moves differently than the other side. It is understood that more than two cams 214 can be used can be used.
• Figure 16A illustrates a perspective view of a second embodiment of a vertical cam configuration.
• a single cam 216 is positioned vertically against the middle of the back surface 51. This allows the pressure between the rejector plate 50 and the chassis cold plate 60 to self-balance, as the force is applied as a single point on the back of the rejector plate 50.
• Figure 16B illustrates a top down view of the second embodiment of the vertical cam configuration of Figure 16A. The shape of the cam 216 determine translation of the rejector plate 50.
• the cams move the rejector plate 50 from right to left, toward the chassis cold plate 60.
• the cams do not retract the rejector plate 50 from the chassis cold plate 60.
• one or more springs are attached to the back surface 51 of the rejector plate 50.
• the cams must overcome the spring force of the attached spring.
• the cams are disengaged by rotating them to their initial positions. In response, the spring pulls the rejector plate 50 away from the chassis cold plate 60, for example from left to right in the Figures 12-16B.
• the cams can be coupled to a common linkage assembly.
• the common linkage assembly such as an actuating rod, is used to actuate the earns.
• the linkage assembly can be manually operated.
• the linkage assembly can also be coupled to the electronics server locking mechanism used to lock the electronics server into the rack when the electronics server is installed. In this manner, the cams are actuated concurrently with the rack locking mechanism such that the action of locking the electronics server into the rack causes the rejector plate and the chassis cold plate to engage in thermal contact.
• FIG. 17 illustrates a top down view of a first ramp translation mechanism.
• a rejector plate 150 includes one or more ramp profiles 152 along a back surface 151.
• An actuating mechanism 220 is configured with one or more ramp profiles 222 that mate to the one or more ramp profiles 152. The actuating mechanism is positioned against a fixed surface within the chassis guide
• the actuating mechanism 220 is fixed relative to the chassis guide 52 such that as the electronics server 34 is installed in the rack, the rejector plate 150 slides along the actuating mechanism 220 such that the ramp profiles 222 slide along the ramp profiles 152, thereby forcing the rejector plate 152 against the chassis cold plate 60. As shown in Figure 17, the rejector plate 150 is translated from right to left according to this procedure. In other embodiments, the actuating mechanism 220 slides along the chassis guide 52.
• a separate step is performed in which the actuating mechanism 220 is moved along the chassis guide, for example from top to bottom in Figure 17, such that the ramp profiles 222 slide along the ramp profiles 152, thereby forcing the rejector plate 152 against the chassis cold plate 60.
• This step can be automatically performed as part of as locking procedure used to lock the electronics server 34 into the rack, or this step can be manually performed after the locking procedure.
• Figure 18 illustrates a top down view of a second ramp translation mechanism.
• the second ramp translation mechanism functions similarly to the first ramp translation mechanism with the exception that the ramp profiles 222 on the actuating mechanism are replaced by rollers.
• an actuating mechanism 230 is configured with one or more rollers 232 that mate to the one or more ramp profiles 152.
• the actuating mechanism is positioned against a fixed surface, such as the inside surface of the chassis guide 52.
• rollers 232 reduce the friction against the ramp profiles 152.
• the actuating mechanism 230 is fixed relative to the chassis guide 52.
• the actuating mechanism 220 slides along the chassis guide 52.
• Alternative slides 234 can also be used to further reduce the friction generated when moving the actuating mechanism 230. It is understood that the location of the ramps and the rollers can be reversed while achieving
• first and second ramp translation mechanisms require a retracting means for disengaging the rejector plate 150 from the chassis cold plate 60.
• Spring means similar to that described above in relation to the cam configurations can be included in either the first or second ramp translation mechanisms.
• Another translation mechanism used is a scissor jack positioned between the rejector
• Figure 19 illustrates a top down view of a scissor jack translation mechanism.
• a scissor jack 242 is positioned between the back surface 51 of the rejector plate 50 and a fixed surface within the chassis guide 52, such as the inside surface of the chassis guide 52.
• An actuating rod 240 is coupled to open and close the scissor jack 242. For example, as applied to Figure 19, upward movement of the actuating
• O rod 240 opens the scissor jack 242, and downward movement of the actuating ord 240 closes the scissor jack 242.
• the scissor jack 242 can be held in place within the chassis guide 52 by an alternative support 244.
• the actuating rod 240 is automatically actuated as part of locking procedure used to lock the electronics server 34 into the rack. In other embodiments, the actuating rod 240 is moved independently of the locking procedure.
• FIG. 2OA illustrates a top down view of an exemplary embodiment of the translation mechanism using cams, slots,
• a cold plate extension 252 is attached to the rejector plate 50.
• One or more cams 260 are coupled to the chassis guide 52 ( Figure 9) at a center position 262. The cams 260 are free to rotate about the center position 262, but are otherwise linearly fixed relative to the chassis guide 52.
• the center position 262 is positioned within a center slot 256 of the cold plate extension 252.
• Each cam 260 includes a pin 264 that extends perpendicularly from a surface of the cam. The pin 262 fits within a pin slot 254 of the cold plate extension 252.
• the cams 260 are rotated counterclockwise. Counterclockwise rotation of the cams 260 forces the pin 262 along the pin slot 254 in the Y-direction (downward relative to Figure 20B), which generated a linear force in the X-direction. This linear force moves the cold plate extension 252, and therefore the rejector plate 50, in the X-direction to disengage the chassis cold plate 60, as illustrated in Figure 2OA.
• Each of the cams 260 can be linked together via a mechanical linkage (not shown). In some embodiments, the mechanical linkage is automatically actuated as part of the locking procedure used to lock the electronics server 34 into the rack. In other embodiments, the mechanical linkage is moved independently of the locking procedure.
• the profile of the pin slot 254 is shown in Figures 2OA and 2OB as a straight line in the Y direction, which results in substantially a linear conversion of rotational movement to linear movement. This profile can be adjusted, thereby altering the mechanical force profile applied to the rejector plate.
• FIG. 21A illustrates a top down view of an exemplary embodiment of the translation mechanism using slots and pins in a disengaged position.
• Figure 21C illustrates a side view of the exemplary translation mechanism of Figure 21A. In the disengaged position, the rejector plate 50 is disengaged from the chassis cold plate 60.
• a cold plate extension 352 is attached to the rejector plate 50.
• the cold plate extension 352 includes one or more slots 354.
• An actuating rod 320 includes one or more pins 322 that extend perpendicularly from a surface of the actuating rod. Each pin 322 fits into one of the slots 354 of the cold plate extension 352.
• the actuating rod 320 slides back and forth in the Y-direction, but is fixed in the X-direction. As the actuating rod 320 moves in the Y-direction, the pins 322 move within the slots 354. Linear movement of the actuating rod 320 in the Y-direction is converted to linear movement of the cold plate extension 352, and therefore the attached rejector plate 50, depending on a slot profile of the slots 354.
• the slot profiles of each slot 354 can be the same, or different, depending on the required motion of the rejector plate 50.
• Varying the slot profile provides mechanical variations in the force applied to the rejector plate 50.
• the rejector plate 50 is uniformly moved in the X-direction to engage the chassis cold plate
• Figure 21C illustrates a side view of the exemplary translation mechanism of Figure 21 A.
• the actuating rod 320 moves perpendicular to the page.
• the actuating rod 320 is moved in the Y-direction. In some embodiments, the actuating rod 320 is automatically actuated as part of the locking procedure used to lock the electronics server 34 into the rack. In other embodiments, the actuating rod 320 is moved independently of the locking procedure. It is understood that alternative configurations to the one shown in Figures 21A and 21B are also contemplated.
• Figure 22 illustrates an alternative configuration of the chassis cold plate and rejector plate.
• the chassis cold plate 260 is configured as U-shaped, and each electronics server is configured with two rejector plates 250.
• the rejector plates 250 are aligned inside the U- shaped chassis cold plate 260, as shown in Figure 22.
• An expansion mechanism 270 is positioned between the rejector plates 250.
• the expansion mechanism include, but are not limited to, a bellows or a bladder.
• the expansion mechanism 270 can also be any one of the previously described actuation means, or a variation thereof.
• the configuration described above can include the force containment assembly 52 (as shown in Figure 22) or not include the force containment assembly 52.
• the actuating force used to actuate the various translation mechanism described herein above can be provided using various actuating means. Examples of such actuating means include, but are not limited to, mechanical linkages, such as pull/push rods, screw drives, hydraulics, electro-mechanical motors or actuators, and pneumatics.
• the rejector plate of the electronics server can be movable or fixed relative to the electronics server circuit board, and/or the chassis cold plate of the rack can be movable or fixed relative to the rack chassis, and any of the mounting assemblies and actuating mechanisms described herein can be applied to various combinations of movable and/or fixed rejector plate and chassis cold plate configurations.
• thermal interface is configurable on all surface of the electronics server, except for the rack connection side, depending on the application.

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• Engineering & Computer Science (AREA)
• Computer Hardware Design (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Cooling Or The Like Of Electrical Apparatus (AREA)
• Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)

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• 2007
  • 2007-02-16 TW TW096106290A patent/TWI371684B/zh not_active IP Right Cessation
  • 2007-02-16 US US11/707,350 patent/US7599184B2/en active Active
  • 2007-02-16 JP JP2008555400A patent/JP5208769B2/ja active Active
  • 2007-02-16 CN CN200780013580.6A patent/CN101438638B/zh active Active
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  • 2007-02-16 WO PCT/US2007/004236 patent/WO2007098077A2/en not_active Ceased
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  • 2007-02-16 EP EP07751027.9A patent/EP1987309B1/en active Active
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