Arrangement for heat transfer between a heat source and a heat sink

• US 4,151,547 A
• Filed: 09/07/1977
• Issued: 04/24/1979
• Est. Priority Date: 09/07/1977
• Status: Expired due to Term

• Current Assignee: GE Fanuc Automation North America Incorporated, General Electric Company
• Original Assignee: General Electric Company
• Inventors: Rhoades, John M., Montanino, Patrick J.
• Primary Examiner(s): James, Andrew J.
• Application Number:
  US05/831,211
• Time in Patent Office: 594 Days
• Field of Search: 357/79, 357/81, 165/80, 165/105, 174/16 HS, 361/387, 361/388, 361/386, 361/389
• US Class Current: 257/718
• CPC Class Codes: H01L 2023/4031 Packaged discrete devices, e.g. to-3 housings, diodes
• CPC Class Codes: H01L 2023/405 heatsink to package
• CPC Class Codes: H01L 2023/4068 Heatconductors between device and heatsink, e.g. compliant heat-spreaders, heat-conducting bands
• CPC Class Codes: H01L 23/3736 Metallic materials H01L23/3732, H01L23/3733, H01L23/3735, H01L23/3737, H01L23/3738 take precedence
• 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

Abstract

An arrangement for improving the transfer of heat from a heat source to a heat sink. The improvement is provided by the use of a malleable dimpled wafer which is deformed between the heat source and heat sink so as to improve the direct contacting of the juxtaposed adjacent surfaces of the heat source and heat sink, thereby resulting in improved thermal conductivity therebetween.

Claims

1. A heat transfer arrangement comprising:

(a) a heat source;

(b) a heat sink; and

(c) a malleable wafer having a plurality of dimples thereon, said dimpled wafer being deformed between said heat source and said heat sink during emplacement therebetween for providing increased direct contacting of the adjacent heat sink and heat source surfaces, whereby to improve the thermal conductivity therebetween.

2. A heat transfer arrangement according to claim 1, wherein said heat source is a power transistor.

3. A heat transfer arrangement according to claim 2, wherein said power transistor is housed within a TO₃ type package.

4. A heat transfer arrangement according to claim 1, wherein said wafer has an areal dimension approximately the same as the areal dimension of the adjacent surface of said heat source.

5. A heat transfer arrangement according to claim 1, wherein said wafer is dimpled to approximately its same normal thickness.

6. A heat transfer arrangement according to claim 1, wherein said deformed wafer is in contact with approximately a minimum of 50% of the adjacent juxtaposed surface of each of said heat sink and said heat source.

7. A heat transfer arrangement according to claim 1, wherein said dimples of said wafer number approximately 21 per lineal inch, and are spaced apart by a distance of approximately 10 to 60 mils center to center, while said wafer is approximately 5 mils thick.

8. A heat transfer arrangement according to claim 1, wherein the yield strength of said wafer is less than 1000 psi.

9. A heat transfer arrangement according to claim 1, wherein said wafer is comprised of a material selected from a group comprising gold, silver, zinc and lead.

10. A heat transfer arrangement according to claim 1, wherein said dimples of said wafer extend from a top surface thereof.

11. A heat transfer arrangement according to claim 10, further comprising an adhesive attached to the top surface of said wafer to bond the top surface of said wafer to said heat source.

12. A heat transfer arrangement according to claim 1, wherein said dimples of said wafer are arranged in rows, and each of said rows of dimples is staggered with respect to an adjacent row of dimples to maximize the density of said dimples on said wafer.