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EP-4456691-B1 - ACTIVELY COOLED HEAT-DISSIPATION LIDS FOR COMPUTER PROCESSORS AND PROCESSOR ASSEMBLIES

EP4456691B1EP 4456691 B1EP4456691 B1EP 4456691B1EP-4456691-B1

Inventors

  • MALOUIN, Bernard
  • MIZERAK, JORDAN

Dates

Publication Date
20260513
Application Date
20230302

Claims (20)

  1. A heat-dissipation lid (210), comprising: a first plate (211) formed from a thermally conductive material, having a first surface (212) configured to be placed in thermal communication with a heat-generating device (202) affixed to a printed circuit board or processor carrier (201), and a second surface (213) located on an opposite side of said first plate (211) from the first surface (212); a first raised sidewall (214) extending from the first surface (212) of the first plate (211), the first raised sidewall (214) being configured for fastening the heat-dissipation lid (210) to the printed circuit board or processor carrier (201) with the first surface (212) spaced apart from the printed circuit board or processor carrier (201) such that the first raised sidewall (214), the first surface (212) of the first plate (211) and the printed circuit board or processor carrier (201) together define a device chamber (221) within which the heat-generating device (202) will reside after the heat-dissipation lid (210) is fastened to the printed circuit board or processor carrier (201); a second raised sidewall (215), extending from the second surface (213) of the first plate (211); a second plate (216), connected to the second raised sidewall (215) opposite from the second surface (213) of the first plate (211), the second plate (216) being spaced apart from the first plate (211) so that the second raised sidewall (215), the second plate (216) and the second surface (213) of the first plate (211) together define a fluid chamber (222) within which a coolant fluid (230) may flow, the fluid chamber (222) being configured to prevent the cooling fluid (230) from entering the device chamber (221); an inlet conduit (217), in fluid communication with the fluid chamber (222), configured to admit the coolant fluid (230) into the fluid chamber (222); and an outlet conduit (218) in fluid communication with the fluid chamber (222) configured to let the coolant fluid (230) pass out of the fluid chamber (222); whereby the coolant fluid (230) admitted into the fluid chamber (222) via the inlet conduit (217) may directly contact and absorb heat from the second surface (213) of the first plate (211) in thermal communication with the heat-generating device (202) before passing out of the fluid chamber (222) via the outlet conduit (218), the heat-dissipation lid (210) characterised by further comprising: a third plate (540), disposed between the first plate (211) and the second plate (216), and spaced apart from both the first plate (211) and the second plate (216) so that the third plate (540) divides the fluid chamber (222) into a first reservoir (541) and a second reservoir (542), wherein the second surface (213) of the first plate (211) comprises a boundary of the second reservoir (542) of the fluid chamber (222); and a plurality of nozzles (543) fluidly connecting the first reservoir (541) of the fluid chamber (222) and the second reservoir (542) of the fluid chamber (222), the plurality of nozzles (543) being configured (i) to accelerate the coolant fluid (230) passing out of the first reservoir (541) of the fluid chamber (222) and into the second reservoir (542) of the fluid chamber (222), and (ii) to direct the coolant fluid (230) flowing into the second reservoir (542) to strike the second surface (213) of the first plate (211).
  2. The heat-dissipation lid of claim 1, wherein the second surface of the first plate comprises a surface area enhancement feature configured to increase an amount of heated surface area on the second surface that will be exposed to the coolant fluid as the coolant fluid flows through the fluid chamber.
  3. The heat-dissipation lid of claim 2, wherein the surface area enhancement feature comprises; a plurality of pin fins; or a plurality of skived fins; or one or more flow channels; a plurality of grooves; or a surface roughening; or one or more etchings; or a combination of two or more thereof.
  4. The heat-dissipation lid of claim 1, further comprising a fastener configured to affix the heat-dissipation lid to the printed circuit board or processor carrier.
  5. The heat-dissipation lid of claim 4, wherein the fastener comprises; an adhesive; or a solder; or a bolt; or a screw; or a combination of two or more thereof.
  6. The heat-dissipation lid of claim 1, wherein: the inlet conduit is fluidly connected to the first reservoir of the fluid chamber; and the outlet conduit is fluidly connected to the second reservoir of the fluid chamber.
  7. The heat-dissipation lid of claim 1, wherein each nozzle in the plurality of nozzles in the third plate comprises a chamfer or a taper to reduce a pressure drop in the coolant fluid as the coolant fluid flows from the first reservoir of the fluid chamber to the second reservoir of the fluid chamber via said each nozzle.
  8. The heat-dissipation lid of claim 1, wherein: the third plate has a fluid-distribution reservoir side and a fluid-collection reservoir side; each nozzle in the plurality of nozzles has a first diameter on the fluid-distribution reservoir side of the third plate and a second diameter on the fluid-collection reservoir side of the third plate; and the first diameter is greater than the second diameter.
  9. The heat-dissipation lid of claim 1, wherein at least one of the inlet conduit and the outlet conduit passes through the second plate.
  10. The heat-dissipation lid of claim 1, wherein at least one of the inlet conduit and the outlet conduit passes through the second raised sidewall.
  11. The heat-dissipation lid of claim 1, wherein the heat-dissipation lid is a unitary structure.
  12. The heat-dissipation lid of claim 1, wherein the heat-dissipation lid comprises multiple components joined together by at least one fastener.
  13. The heat-dissipation lid of claim 12, wherein the multiple components are formed from the same construction material.
  14. The heat-dissipation lid of claim 12, wherein the multiple components are not formed from the same construction material.
  15. The heat-dissipation lid of claim 14, wherein the multiple components are formed from construction materials having different thermal conductivities.
  16. The heat-dissipation lid of claim 1, wherein the first surface of the first plate comprises at least two sub-surfaces of different heights.
  17. The heat-dissipation lid of claim 1, wherein the first surface of the first plate comprises indents or protrusions configured to provide additional spacing between the first plate and a heat-generating device.
  18. The heat-dissipation lid of claim 1, further comprising a flange disposed on the first raised sidewall, the flange being configured to accept a screw that passes through the flange to fasten the heat-dissipation lid to the printed circuit board or processor carrier.
  19. The heat-dissipation lid of claim 18, further comprising a pad located between the flange and the printed circuit board or processor carrier.
  20. The heat-dissipation lid of claim 18, further comprising a spacer disposed between the flange and the printed circuit board or processor carrier.

Description

Technical Field Heat-management systems for high-powered, high-performance computer processors, processor assemblies and electronic devices, and more particularly, heat-management systems involving liquid cooling systems and methods. Background Art Modern computer processors (e.g., CPUs, GPUs, FPGAs, ASICs, etc.) and processor assemblies used in high-performance computing applications, such as supercomputing, artificial intelligence, networking, and other processing-intense applications, typically include a very large number of very small semiconductor dies arranged and attached to printed circuit boards in increasingly dense patterns. Because each one of these small and densely packed semiconductor dies includes one or more heat-generating devices, processing assemblies in electronic devices comprising such densely packed semiconductor dies can generate an enormous amount of heat during operation. The additional heat can raise the internal temperature of the processing assemblies. If the internal temperature of a processing assembly exceeds a certain maximum safe operating temperature, the excessive heat could damage the processing assembly and thereby significantly reduce the operating lifespan of the processing assembly or, in some cases, may cause a catastrophic failure of the processing assembly. Accordingly, as semiconductor dies continue to get smaller, and processing assemblies for electronic devices continue to be designed and manufactured to hold increasingly larger numbers of densely packed semiconductor dies, the demand for better and more efficient methods for removing heat from processing assemblies for electronic devices will continue to rise. Removing excess heat generated by many very small, densely packed semiconductor dies is technically challenging because small semiconductor dies have very limited surface areas available for cooling via thermal conduction. Attempts to address this problem have included placing an integrated heat spreader (IHS), sometimes referred to as a "lid," in thermal communication with the semiconductor dies in processor assemblies. The lid is typically formed from a thermally conductive material and, when placed in thermal communication with a heated surface, tends to draw the heat from the heated surface and spread the heat into a larger area having a higher rate of heat dissipation. This lowers the temperature of the processor assembly and makes it easier to keep the processor assembly cool. Notably, however, the operation of such conventional integrated heat spreaders, or lids, is entirely passive. Moreover, after the lid is attached to the semiconductor dies, a heat-sink is typically attached to the lid to promote convection cooling, such as with air or a liquid coolant. Typically, a thermal interface material (TIM) must be disposed between the lid and the heat-sink, to avoid air gaps forming a thermal blanket between the microscopically rough lid and heat-sink mating surfaces. Unfortunately, however, the TIM creates an extra layer of resistance that the heat-sink must overcome, which decreases the heat transfer efficiency, and therefore limits the heat dissipation and reduces processor performance. Furthermore, installing heat-sinks and their thermal interface materials on the lids is traditionally a substantially manual process, which increases manufacturing time, as well as the amount of manual labor required to produce processing assemblies with adequate cooling capabilities. FIG. 1 shows an example of a prior art processing assembly 100 comprising a traditional lid 100. As shown in FIG. 1, a heat-generating device 102, such as a semiconductor die, is disposed on a printed circuit board 101. A passive lid 104, typically formed from a thermally conductive metal, is disposed on printed circuit board 101 via a fastener 105, often an adhesive. The passive lid 104 is placed in thermal communication with the heat-generating device 102 via a first thermal interface material 103 (known to those skilled in the art as TIM1), allowing heat to spread from the heat-generating device 102 having a small area footprint into the larger area footprint of the passive lid 104. The first thermal interface material 103 often provides a structural bond between the lid 104 and the heat-generating device 102, in addition to providing thermal communication, but need not do so in all cases. A heat-sink 107 is then placed in thermal communication with the passive lid 104 via a second thermal interface material 106 (known to those skilled in the art as TIM2). The second thermal interface material 106 typically does not provide a structural bond between the heat-sink 107 and the passive lid 104, though fasteners (not shown) are often included to do so. The heat-sink 107 is typically formed from a thermally conductive metal, and transmits the heat from the passive lid 104, via the second thermal interface material 106, to be taken away via a flowing coolant 111 in fluid chamber 110. The