Stacked wafer electronic package

• US 4,956,746 A
• Filed: 03/29/1989
• Issued: 09/11/1990
• Est. Priority Date: 03/29/1989
• Status: Expired due to Fees

• Current Assignee: Hughes Aircraft Company (Rtx Corporation)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Finnila, Charles A., Gates, Louis E. Jr.
• Primary Examiner(s): Tolin, Gerald P.
• Application Number:
  US07/329,991
• Time in Patent Office: 531 Days
• Field of Search: 174/15.1, 211/41, 357/76, 357/82, 165/80.4, 165/104.33, 361/393-396, 361/382-388, 361/412, 361/413
• US Class Current: 361/699
• CPC Class Codes: H01L 2225/06589 Thermal management, e.g. cooling
• CPC Class Codes: H01L 25/0657 Stacked arrangements of devices
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

The electronic package (10) is comprised of a plurality of support plates (12-24), each of which has a plenum therein and preferably webs extending into the plenum for fluid flow control and heat transfer. A wafer (104) is mounted in a recess (100) in the support plate (12) so that fluid in the plenum (52) directly cools the wafer. Electrical connection is by flexible cable (108) to an exterior printed wiring board (40). The package may have any selected number of support plates, and each support plate may carry one full-sized wafer for compact packaging.

Claims

1. An electronic package comprising:

at least first and second support plates and a bottom support plate, each of said support plates having a support surface thereon, a semiconductor wafer directly supported on said support surface of each of said support plates, each of said support plates having a plenum formed therein, said first and second support plates and said bottom support plate being stacked so that said first support plate is on tope of said second support plate so that said plenum of said first support plate directly faces said support surface of said second support plate;

a top plate engaging on and covering said first support plate and a bottom plate beneath and covering the bottom of said bottom support plate, said top plate, said support plates and said bottom plate being stacked;

a plurality of webs formed in each of said plenums so that aid webs extend toward the support surface of the facing support plate to lie closely adjacent said semiconductor wafer supported on said facing support surface, a resilient adhesive between said webs and said semiconductor wafer so that said semiconductor wafer is supported by said webs on the side of said semiconductor wafer away from said support surface and said webs and said adhesive enclose channels through each plenum over said semiconductor wafers;

a fluid opening in said bottom plate, a fluid opening in said top plate, said plenums being arranged so that fluid entering one of said openings passes through said plenums to the other of said openings so that said wafers on said support surfaces are directly in contact with fluid and are cooled by fluid passing through said plenums.

2. The package of claim 1 wherein:

at least one interconnection board is mounted on said package;

and further including;

a flexible cable having a plurality of conductors therein, said plurality of conductors being attached to one of said wafers mounted on said surfaces and said flexible cable being supported on said interconnection board so that electrical connection is made between a wafer on said interior wafer support surface of said package and said interconnection board.

3. The package of claim 2 wherein said support plates are sealed with respect to each other and sealed around said flexible cable so that liquid coolant can be employed in said plenums without leakage from said package.

4. The package of claim 2 wherein each said support plate has first and second sides and said wafer support surface is on said first side of each said support plate and said plenum is formed as a recess in said second side of each of said support plate so that said support surface on said second support plate is exposed to said plenum on said second side of said first support plate.

5. The package of claim 4 wherein there is a plurality of flexible cables extending from each of said support plates and said plurality of flexible cables is engaged and supported by said interconnection board, said interconnection board having printed wiring conductors thereon interconnected to conductors in said flexible cables.

6. An electronic package comprising:

a top plate and a bottom plate, said top and bottom plates having an inlet opening and an outlet opening;

a plurality of support plates each having a first side and a second side, said support plates being positioned between said top and bottom plates to form a stack of support plates, said top and bottom plates and said support plates being secured together to form a separable unitary structure;

each of said support plates having a wafer support surface on the first side thereof, a wafer mounted on each said support surface, each of said support plates having a recess in the second side thereof forming a plenum, a plurality of webs formed in each said plenum, said support plates being stacked so that said plenum, said support plates being stacked so that said plenum in one said support plate faces said support surface of and adjacent said support plate, said webs being sufficiently long so that they substantially engage said wafers to substantially enclose channels through each plenum between said webs, said support plates each having at least one opening therethrough so that fluid entering said inlet and passing out of said outlet passes through said plenums for cooling wafers supported on said support surfaces and facing said plenums.

7. The package of claim 6 wherein there are webs formed in said plenums which extend towards the support surface of the facing support plate.

8. The package of claim 6 wherein said webs extend substantially all the way across said plenum but terminate short of the plenum wall so as to permit fluid flow to the spaces between said webs.

9. The package of claim 8 wherein there is a plurality of openings through each of said support plates adjacent said plenum wall so that fluid can flow from one plenum to the next.

10. The package of claim 6 wherein there is adhesive between each said web ant the adjacent wafer so that each web is sealed to said wafer on said facing support surface to enclose said channels through each plenum between said webs.

11. The package of claim 10 wherein an interconnection board is mounted on said package and a flexible cable has its outer end secured to said interconnection board and its inner end positioned for attachment to a wafer so that electrical connections may be made to wafers on said support surface.

12. The package of claim 11 where further flexible cables are provided and are sealed with respect to said support plates so that said plenums are enclosed to avoid fluid leakage from said plenums.

13. The package of claim 12 wherein at least one of said flexible cables extends into each said plenum and each of said plurality of cables is attached to said interconnection board, said interconnection board having printed wiring circuits thereon and said flexible cables having at least some of their conductors connected to said printed wiring conductors on said interconnection board.

14. The package of claim 13 wherein there are two of said interconnection boards on said package and flexible cables each having a plurality of conductors extend from each said support surface to each of said interconnection boards.

15. The package of claim 6 wherein a interconnection board is mounted on said package and a flexible cable has its outer end secured to said interconnection board and its inner end positioned for attachment to a wafer so that electrical connections may be made to wafers on said support surface.

16. The package of claim 15 wherein further flexible cables are provided and are sealed with respect to said support plates so that said plenums are enclosed to avoid fluid leakage from said plenums.

17. The package of claim 16 wherein said plurality of flexible cables extends into said plenums and each of said plurality of cables is attached to said interconnection board, said interconnection board having printed wiring circuits thereon and said flexible cables having at least some of their conductor connected to said printed wiring conductors on said interconnection board.

18. The package of claim 17 wherein there are two of said interconnection boards on said package and said flexible cables each having a plurality of conductors extend from each said support surface to each of said interconnection boards.

19. The package of claim 11 further including a semiconductor wafer mounted on a said support surface, said semiconductor wafer being electrically connected to said flexible cable and said semiconductor wafer being passivated to eliminate contact between said semiconductor wafer and fluid in said plenum.

20. The package of claim 15 further including a semiconductor wafer mounted on each said support surface, said semiconductor wafer being electrically connected to said flexible cable and said semiconductor wafer being passivated to eliminate contact between said semiconductor wafer and fluid in said plenum.

21. An electronic package comprising:

a top plate and a bottom plate, said top and bottom plates having an inlet opening and an outlet opening;

a plurality of support plates, each said support plate having a first side and a second side, said support plates being positioned between said top and bottom plates to form a stack of support plates, said top and bottom plates and said support plates being secured together to form a separable unitary structure;

each of said support plates having a wafer support surface on the first side thereof and an integrated surface wafer directly mounted on each said wafer support surface, each of said support plates having a recess in the second side thereof forming a plenum so that said plenum on one said support plate faces said semiconductor wafer on said support surface on an adjacent said support plate, said support plates each having at least one opening therethrough so that fluid entering said inlet and passing out of said outlet passes through said plenums for cooling said semiconductor wafers supported on said support surfaces and facing said plenum;

an interconnection board mounted on said package, a plurality of flexible cables each having a board end and a wafer end, each of said flexible cables having a plurality of conductors therein with said conductors at said board end of said cables being connected to said interconnection board and said conductors on said wafer end being connected to said semiconductor wafers, said flexible cables extending between said support plates with their conductors extending into said plenums, said flexible cables being sealed with respect to said support plates so that said plenums are enclosed.