Power electronics cooling apparatus

• US 6,016,007 A
• Filed: 10/16/1998
• Issued: 01/18/2000
• Est. Priority Date: 10/16/1998
• Status: Expired due to Fees

• Current Assignee: Perfect Galaxy International Limited
• Original Assignee: Northrop Grumman Corporation
• Inventors: Sanger, Philip Albert, Garcen, Walter, Lindberg, Frank A.
• Primary Examiner(s): Clark, Sheila V.
• Application Number:
  US09/206,242
• Time in Patent Office: 459 Days
• Field of Search: 257/746, 257/747, 257/712, 257/714, 257/717, 257/706, 257/707, 257/705
• US Class Current: 257/714
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48139 with an intermediate bond, e.g. continuous wire daisy chain
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/4846 with multiple bonds on the same bonding area
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/49111 the connectors connecting two common bonding areas, e.g. Litz or braid wires
• CPC Class Codes: H01L 2224/49113 the connectors connecting different bonding areas on the semiconductor or solid-state body to a common bonding area outside the body, e.g. converging wires
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 23/473 by flowing liquids H01L23/4332, H01L23/4338 take precedence
• 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 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/1305 Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 2924/13055 Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/19105 in a side-by-side arrangement on a common die mounting substrate

Abstract

A semiconductor cooling arrangement wherein a semiconductor is affixed to a thermally and electrically conducting carrier such as by brazing. The coefficient of thermal expansion of the semiconductor and carrier are closely matched to one another so that during operation they will not be overstressed mechanically due to thermal cycling. Electrical connection is made to the semiconductor and carrier, and a porous metal heat exchanger is thermally connected to the carrier. The heat exchanger is positioned within an electrically insulating cooling assembly having cooling oil flowing therethrough. The arrangement is particularly well adapted for the cooling of high power switching elements in a power bridge.

Claims

1. A cooling arrangement for cooling a semiconductor circuit, comprising:

(A) a semiconductor having a predetermined CTE;

(B) a carrier having first and second sides, and having a predetermined CTE;

(C) said semiconductor being mounted on, and affixed to said first side of said carrier;

(D) said carrier being both thermally and electrically conductive;

(E) the difference between said CTEs of said semiconductor and said carrier being no more than about 1 to 2 ppm per degree centigrade;

(F) means making electrical connection with said semiconductor on one side thereof;

(G) means making electrical connection with said carrier;

(H) a cooling assembly thermally connected to said second side of said carrier for extracting heat therefrom conducted from said semiconductor;

(I) said cooling assembly including a dielectric housing having a cooling fluid inlet for introduction of a cooling fluid, and a cooling fluid outlet.

2. An arrangement according to claim 1 wherein:

(A) said semiconductor is brazed to said carrier.

3. An arrangement according to claim 1 wherein:

(A) said semiconductor is selected from the group consisting of silicon, silicon carbide, gallium arsenide and gallium nitride.

4. An arrangement according to claim 1 wherein:

(A) said cooling fluid is a dielectric oil.

5. An arrangement according to claim 1 which includes:

(A) a heat exchanger in the fluid flow path between said inlet and said outlet.

6. An arrangement according to claim 5 wherein:

(A) said heat exchanger is a porous metal block.

7. An arrangement according to claim 6 wherein:

(A) said dielectric housing has a floor portion; and

(B) said porous metal block touches said floor portion.

8. An arrangement according to claim 1 wherein:

(A) said carrier is a metal matrix composite.

9. An arrangement according to claim 8 wherein:

(A) said metal matrix composite is a copper/graphite composite.

10. An arrangement according to claim 1 wherein said means for making electrical connection with said carrier includes:

(A) an electrical bus connected to said second side of said carrier.

11. An arrangement according to claim 10 wherein:

(A) said bus is planar.

12. An arrangement according to claim 11 wherein:

(A) said bus is soldered to said carrier.

13. An arrangement according to claim 1 wherein:

(A) said semiconductor is a circuit having at least one high power switching device.

14. An improved cooling arrangement for a power bridge having a plurality of ac phases, each said phase comprising:

(A) a semiconductor switching circuit including at least first and second serially connected high power semiconductor switching elements having a predetermined CTE;

(B) said first and second switching elements being bonded to respective first and second thermally and electrically conducting carriers each having a predetermined CTE closely matching that of the switching element to which it is bonded;

(C) a laminated structure including predetermined layers having a window therein into which said carriers and switching elements are positioned, and including positive, negative and output planar electrical buses;

(D) means making predetermined electrical connection of said switching elements to said positive, negative and output buses;

(E) heat exchangers thermally connected to predetermined ones of said buses;

(F) a dielectric housing having upper and lower portions connected together, with said laminated structure sandwiched therebetween, along with said switching elements, buses and heat exchangers;

(G) said dielectric housing having a cooling fluid inlet for introduction of a cooling fluid, and a cooling fluid outlet;

(H) said heat exchangers being in the fluid flow path between said inlet and said outlet.

15. An arrangement according to claim 14 wherein:

(A) said negative bus is coplanar with said carriers.

16. An arrangement according to claim 14 wherein:

(A) said positive bus is coplanar with said output bus.

17. An arrangement according to claim 14 wherein:

(A) said laminated structure includes upper and lower printed circuit boards, with said buses sandwiched therebetween.

18. An arrangement according to claim 17 wherein:

(A) said upper and lower portions of said housing include respective O-rings; and

B) said O-rings make a fluid tight seal with said upper and lower printed circuit boards, respectively.

19. An arrangement according to claim 18 wherein:

(A) said lower printed circuit board includes at least one aperture through which said cooling fluid may flow to contact and cool said switching elements.

20. An arrangement according to claim 14 wherein:

(A) said lower portion of said housing has a floor; and

wherein (B) said heat exchangers contact said floor.

21. An arrangement according to claim 14 wherein:

(A) said heat exchangers are porous metal blocks.

22. An arrangement according to claim 21 wherein:

(A) means are provided within said lower portion of said housing to form, along with said heat exchangers, a central fluid transport channel and two outside fluid transport channels, whereby said cooling fluid is introduced into said central channel and flows through said heat exchangers to said outside channels and then to said fluid outlet.

23. An arrangement according to claim 22 wherein:

(A) said cooling fluid is a dielectric oil.

24. An arrangement according to claim 22 wherein:

(A) said cooling fluid flows through said heat exchangers, in parallel, to said outside channels.

25. An arrangement according to claim 18 wherein:

(A) at least one said carrier is coplanar with, and is formed as an integral part of, a said bus.