COOLING OF COPLANAR ACTIVE CIRCUITS

• US 20120162922A1
• Filed: 12/22/2010
• Published: 06/28/2012
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Cheyne, Scott R., Paquette, Jeffrey, Ackerman, Mark
• Granted Patent: US 8,355,255 B2
• Time in Patent Office: Days
• US Class Current: 361/719
• CPC Class Codes: H01L 23/4006 with bolts or screws
• 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: H01Q 1/02 Arrangements for de-icing; Arrangements for drying-out ; Arrangements for cooling; Arrangements for preventing corrosion
• CPC Class Codes: H01Q 21/0025 Modular arrays
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H05K 1/141 One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters H05K1/142 and H05K1/147 take precedence

Abstract

In one aspect, a system includes a first circuit board that includes integrated circuits, a first thermal spreader coupled to the integrated circuits of the first circuit board, a first compliant board coupled to the first circuit board, a second circuit board that includes integrated circuits and a second thermal spreader coupled to the integrated circuits of the second circuit board. The first circuit board and the first thermal spreader have a first thickness. The second daughter board and the second thermal spreader have a second thickness. The system further includes a second compliant board coupled to the second circuit board, a board assembly coupled to first and second compliant boards and a cold-plate assembly in contact with the first and second thermal spreaders. Either of the first or the second compliant boards is configured to expand or contract to account for the differences between the first and second thicknesses.

Claims

1. An active, electronically scanned array (AESA) panel architecture system comprising:

a first daughter board comprising active circuits;

a first thermal spreader coupled to the active circuits of the first daughter board, the first daughter board and the first thermal spreader having a first thickness;

a first compliant board coupled to the first daughter board;

a second daughter board comprising active circuits;

a second thermal spreader coupled to the active circuits of the second daughter board, the second daughter board and the second thermal spreader having a second thickness different from the first thickness;

a second compliant board coupled to the second daughter board;

a mother board assembly coupled to first and second compliant boards; and

a cold-plate assembly in contact with the first thermal spreader and the second thermal spreader,

wherein either of the first compliant board or the second compliant board is configured to expand or contract to account for the differences in thicknesses between the first thickness and the second thickness.

2. The system of claim 1, further comprising a fastener securing the mother board assembly to the cold-plate assembly and extending through one of the first or second daughter board.

3. The system of claim 1, further comprising a fastener securing the mother board assembly to one of the first or the second thermal spreader.

4. The system of claim 1 wherein the first or second compliant board comprises an RF interface board.

5. The system of claim 1 wherein the first or second compliant board comprises conductive elastomeric contacts on at least one side of the first compliant board.

6. The system of claim 1 wherein the conductive elastomeric contacts comprises a silver-filled elastomer.

7. The system of claim 1 wherein the elastomer has a Shore A durometer of about 90.

8. The system of claim 1 wherein the first or second compliant board and the conductive elastomeric contacts are electrically conductive and configured to provide an RF insertion loss of less than 0.1 dB.

9. The system of claim 1 wherein the first thermal spreader comprises a boss that interfaces with the first daughter board to control gaps between the active circuits of the first daughter board and the first thermal spreader.

10. The system of claim 1 wherein the first thermal spreader comprises a first boss that interfaces with the mother board to control a gap between the cold-plate assembly and the first thermal spreader.

11. An active, electronically scanned array (AESA) panel architecture system comprising:

a first daughter board comprising active circuits;

a first thermal spreader coupled to the active circuits of the first daughter board, the first daughter board and the first thermal spreader having a first thickness;

a first RF interface board coupled to the first daughter board, the first RF interface board comprising compliant elements on at least one side of the first RF interface board;

a second daughter board comprising active circuits;

a second thermal spreader coupled to the active circuits of the second daughter board, the second daughter board and the second thermal spreader having a second thickness different from the first thickness;

a second RF interface board coupled to the second daughter board, the second RF interface board comprising compliant elements on at least one side of the second RF interface board;

a mother board assembly coupled to first and second RF interface boards; and

a cold-plate assembly in contact with the first thermal spreader and the second thermal spreader,

wherein the first and second RF interface boards are configured to expand or contract to account for the differences in thicknesses between the first thickness and the second thickness,

wherein the first RF interface board provides electrical coupling between the active circuits of the first daughter board and the mother board, and

wherein the second RF interface board provides electrical coupling between the active circuits of the second daughter board and the mother board.

12. The system of claim 11, further comprising a first fastener securing the mother board assembly to the cold-plate assembly and extending through one of the first or second daughter board.

13. The system of claim 12, further comprising a second fastener securing one of the first or the second thermal spreader to the mother board assembly.

14. The system of claim 11 wherein the first thermal spreader comprises a first boss that interfaces with the first daughter board to control gaps between the active circuits of the first daughter board and the first thermal spreader.

15. The system of claim 11 wherein the first thermal spreader comprises a second boss that interfaces with the mother board to control a gap between the cold-plate assembly and the first thermal spreader.

16. A system comprising:

a first circuit board comprising integrated circuits;

a first thermal spreader coupled to the integrated circuits of the first circuit board, the first circuit board and the first thermal spreader having a first thickness;

a first compliant board coupled to the first circuit board;

a second circuit board comprising integrated circuits;

a second thermal spreader coupled to the integrated circuits of the second circuit board, the second circuit board and the second thermal spreader having a second thickness different from the first thickness;

a second compliant board coupled to the second circuit board;

a board assembly coupled to first and second compliant boards; and

a cold-plate assembly in contact with the first thermal spreader and the second thermal spreader,

wherein either of the first compliant board or the second compliant board is configured to expand or contract to account for the differences in thicknesses between the first thickness and the second thickness.

17. The system of claim 16, further comprising a fastener securing the board assembly to the cold-plate assembly and extending through one of the first or second circuit board.

18. The system of claim 16, further comprising a fastener securing the board assembly to one of the first or the second thermal spreader.

19. The system of claim 16 wherein the first or second compliant board comprises conductive elastomeric contacts on at least one side of the first compliant board.

20. The system of claim 16 wherein the first thermal spreader comprises a first boss that interfaces with the first circuit board to control gaps between the integrated circuits of the first circuit board and the first thermal spreader.

wherein the first thermal spreader further comprises a second boss that interfaces with the board assembly to control a gap between the cold-plate assembly and the first thermal spreader.