Apparatus for cooling high-density integrated circuit packages

• US 4,612,978 A
• Filed: 04/08/1985
• Issued: 09/23/1986
• Est. Priority Date: 07/14/1983
• Status: Expired due to Fees

• Current Assignee: Technology Enterprises Company Turks and Caicos Islands British West Indiana
• Original Assignee: John M. Cutchaw
• Inventors: Cutchaw, John M.
• Primary Examiner(s): DAVIS JR, ALBERT
• Application Number:
  US06/721,074
• Time in Patent Office: 533 Days
• Field of Search: 165/104.33, 165/DIG. 8, 165/DIG. 10, 165/DIG. 5, 165/185, 165/80 C, 165/46, 357/82, 361/385, 62/259.1
• US Class Current: 165/104.33
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 23/433 Auxiliary members in containers characterised by their shape, e.g. pistons
• CPC Class Codes: H01L 23/473 by flowing liquids H01L23/4332, H01L23/4338 take precedence
• CPC Class Codes: H01L 2924/15312 being a pin array, e.g. PGA

Abstract

An apparatus for cooling a high-density integrated circuit package includes a base in which the circuit package is mounted and a heat exchanger which mounts on the base to enclose the circuit package and carry away the operational heat thereof by means of a coolant which is passed through the heat exchanger. The heat exchanger includes a housing having a coolant chamber with an especially configured thermally conductive wall for engaging the integrated circuit package. The coolant chamber is filled with a plurality of thermally conductive spheroids which are biased into thermally conductive contact with each other and with the special wall to maximize the heat exchange surface in the coolant chamber. The apparatus is preferably employed in combination with a refrigeration system wherein the coolant chamber is the evaporation element of the system for maximum cooling of the integrated circuit package.

Claims

1. An apparatus for cooling a high-density integrated circuit package of the type having a substrate with a plurality of discrete integrated circuits arranged thereon in a predetermined array, said apparatus comprising:

(a) a housing defining an open coolant chamber which is sized so that its opening substantially matches the surface area of the substrate of the integrated circuit package, said housing for positioning in overlaying relationship with respect to the integrated circuit package;

(b) a rigid wall means of thermally conductive material fixedly attached to said housing for sealingly enclosing the coolant chamber thereof and having a heat input surface;

(c) a thermally conductive contact means interposed between the heat input surface of said rigid wall means and the integrated circuit package when said housing is in overlaying relationship therewith, said contact means being conformable to compensate for dimensional variations to provide positive thermal contact with the heat input surface of said rigid wall and with each of the discrete integrated circuits;

(d) said housing having an inlet port and an outlet port by which coolant is passable through the coolant chamber of said housing; and

(e) a plurality of spheroids in the coolant chamber of said housing and substantially filling the coolant chamber, each of said spheroids being of metal for conducting heat away from said rigid wall for maximizing the heat exchange surface area into which the coolant comes in contact when passed through the coolant chamber of said housing.

2. An apparatus as claimed in claim 1 and further comprising:

(a) said rigid wall means being of substantially planar configuration; and

(b) said thermally conductive contact means including,

I. a resiliently compressible means in coextensive contiguous engagement with the heat input surface of said rigid wall,

II. a thin-wall pliable diaphragm in contiguous engagement with said resiliently compressible means and having its peripheral edges affixed to said rigid wall for sealingly enclosing said resiliently compressible means,

III. thermal grease in the area between said rigid wall and said diaphragm.

3. An apparatus as claimed in claim 2 wherein said resiliently compressible means is a woven wire mesh screen.

4. An apparatus as claimed in Claim 1 and further comprising:

(a) said rigid wall being provided at least one substantially V-shaped groove formed therein, said V-shaped groove defining a pair of angular walls and being arranged so as to open away from the coolant chamber of said housing; and

(b) said thermally conductive contact means including,

I. a pair of thermal blocks arranged in a back-toback position within said V-shaped groove of said rigid wall and in slidable bearing engagement with said pair of angular walls defined by said Vshaped groove,

II. biasing means between said pair of thermal blocks for yieldably biasing said pair of thermal blocks into thermally conductive contact with the angular walls of said V-shaped groove of said rigid wall and into thermally conductive contact with at least one of the discrete integrated circuits when said housing is in overlaying relationship with said integrated circuit package.

5. An apparatus as claimed in claim 4 wherein each of said thermal blocks has a vertical wall for engagement with said biasing means, an inclined wall for engagement with one of the angular walls of said V-shaped groove and a base wall for engaging at least one of the discrete integrated circuits.

6. An apparatus as claimed in claim 5 wherein said biasing means between said pair of thermal blocks is an elastomeric pad.

7. An apparatus as claimed in claim 1 and further comprising biasing means in the coolant chamber of said housing and disposed between said housing and said plurality of spheroids for biasing said spheroids into thermally conductive contact with each other and with said rigid wall.

8. An apparatus as claimed in claim 7 wherein said biasing means is a resilient elastomeric pressure pad which is compressingly interposed between said housing and said plurality of spheroids.

9. An apparatus as claimed in claim 8 wherein said resilient elastomeric pressure pad is provided with at least a spaced pair of partitions which depend therefrom into spaced proximity with said diaphragm.

10. An apparatus as claimed in claim 1 wherein said housing comprises:

(a) a roof wall of substantially planar configuration; and

(b) an endless sidewall extending normally from the periphery of said roof wall.

11. An apparatus as claimed in claim 1 and further comprising:

(a) base means defining an open chamber for nestingly receiving the integrated circuit package; and

(b) cooperative elements of a demountable connection on said base means and on said housing for attaching said housing to said base means in overlaying relationship with the integrated circuit package when it is nestingly received in said base means.

12. An apparatus as claimed in claim 11 and further comprising:

(a) said open chamber of said base means being deeper than the thickness dimension of the substrate of the integrated circuit package; and

(b) an endless ring-shaped elastomeric seal mounted on said base means so as to surround the open chamber thereof and configured to extend upwardly from said base means for sealingly engaging said housing.

13. An apparatus as claimed in claim 1 and further comprising a refrigeration system for supplying high pressure liquid refrigerant to said inlet port for evaporation within the coolant chamber of said housing and for receiving the vaporized gaseous refrigerant from said outlet port, compressing and cooling the refrigerant to its liquid state for resupplying thereof to said inlet port.

14. The combination of an apparatus and refrigeration system for cooling a high-density integrated circuit package of the type having a substrate with a plurality of discrete integrated circuits arranged thereon in a predetermined array, said combination comprising:

(a) a housing defining an open coolant chamber which is sized to substantially match the surface area of the substrate of the integrated circuit package, said housing being positionable in overlying relationship with said integrated circuit package and having an inlet port and an outlet port;

(b) a rigid wall means of thermally conductive material affixed to said housing for sealingly enclosing the coolant chamber thereof and having a heat input surface;

(c) a thermally conductive contact means between the heat input surface of said rigid wall means and the integrated circuit package when said housing is in overlying relationship therewith, said contact means being conformable to compensate for dimensional variations to provide positive thermal contact with the heat input surface of said rigid wall and with each of the discrete integrated circuits;

(d) a plurality of spheroids in the coolant chamber of said housing and substantially filling the coolant chamber, said spheroids being formed of metal for conducting heat away from said rigid wall for maximizing the heat exchange surface area within the coolant chamber of said housing; and

(e) a refrigeration system having a refrigerant input line coupled to the inlet port of said housing for supplying high pressure liquid refrigerant to the coolant chamber thereof so that the liquid refrigerant will vaporize therein to absorb operational heat of the integrated circuit package when said housing in in overlaying relationship therewith and the integrated circuit package is operating, said refrigeration system having a refrigerant outlet line coupled to the outlet port of said housing for receiving the vaporized refrigerant therefrom so that said refrigeration system can compress and cool the refrigerant back to a liquid state for resupplying thereof to the inlet port of said housing.

15. The combination of claim 14 and further comprising:

(a) said rigid wall means being of substantially planar configuration; and

(b) said thermally conductive contact means including,

I. a resiliently compressible means in coextensive contiguous engagement with the heat input surface of said inlet,

II. a thin-wall pliable diaphragm in contiguous engagement with said resiliently compressible means and having its peripheral edges affixed to said rigid wall for sealingly enclosing said resiliently compressible means,

III. thermal grease in the area between said rigid wall and said diaphragm.

16. The combination of claim 15 wherein said resiliently compressible means is a woven wire mesh screen.

17. The combination of Claim 14 and further comprising:

(a) said rigid wall being provided with at least one substantially V-shaped groove formed therein, said V-shaped groove defining a pair of angular walls and being arranged so as to open away from the coolant chamber of said housing; and

(b) said thermally conductive contact means including,

I. a pair of thermal blocks arranged in a back-to-back position within said V-shaped groove of said rigid wall and in slidable bearing engagement with said pair of angular walls defined by said V-shaped groove,

II. biasing means between said pair of thermal blocks for yieldably biasing said pair of thermal blocks into thermally conductive contact with the angular walls of said V-shaped groove of said rigid wall and into thermally conductive contact with at least one of the discrete integrated circuits when said housing is in overlying relationship with said integrated circuit package.

18. The combination of claim 17 wherein each of said thermal blocks has a vertical wall for engagement with said biasing means, an inclined wall for engagement with one of the angular walls of said V-shaped groove and a base wall for engaging at least one of the discrete integrated circuits.

19. The combination of claim 18 wherein said biasing means between said pair of thermal blocks is an elastomeric pad.

20. The combination of claim 14 and further comprising biasing means in the coolant chamber of said housing and disposed between said housing and said plurality of spheroids for biasing said spheroids into thermally conductive contact with each other and with said rigid wall.

21. The combination of claim 20 wherein said biasing means is a resilient elastomeric pressure pad which is compressingly interposed between said housing and said plurality of spheroids.

22. The combination of claim 21 wherein said resilient elastomeric pressure pad is provided with at least a spaced pair of partitions which depend therefrom into spaced proximity with said rigid wall.

23. The combination of claim 14 wherein said housing comprises:

(a) a roof wall of substantially planar configuration; and

(b) an endless sidewall extending normally from the periphery of said roof wall.

24. The combination of claim 14 and further comprising:

(a) base means defining an open chamber for nestingly receiving the integrated circuit package; and

(b) cooperative elements of a demountable connection on said base means and on said housing for attaching said housing to said base means in overlaying relationship with the integrated circuit package when it is nestingly received in said base means.

25. The combination of claim 24 and further comprising:

(a) said open chamber of said base means being deeper than the thickness dimension of the substrate of the integrated circuit package; and

(b) an endless ring-shaped elastomeric seal mounted on said base means so as to surround the open chamber thereof and configured to extend upwardly from said base means for sealingly engaging said housing.

26. The combination of claim 14 and further comprising:

(a) said housing being configured to provide a pre-cooling portion within the coolant chamber defined thereby, said pre-cooling portion being disposed proximate the outlet port of said housing; and

(b) said refrigerant input line of said refrigeration system having a terminal portion thereof passing through the pre-cooling portion of said coolant chamber and extending therefrom to the inlet port of said housing for cooling of the liquid refrigerant on its way into the coolant chamber of said housing.

27. The combination of claim 26 wherein the flow of liquid coolant through said refrigerant input line is countercurrent to the flow of vaporized refrigerant through said pre-cooling portion of said coolant chamber for maximizing the heat exchange therebetween.

28. The combination of claim 26 wherein that portion of the refrigerant input line which extends between said coolant chamber and said inlet port of said housing is in the form of a capillary tube.