Metal/ceramic bonding substrate and method for producing same

• US 7,256,353 B2
• Filed: 12/29/2003
• Issued: 08/14/2007
• Est. Priority Date: 12/27/2002
• Status: Active Grant

• Current Assignee: DOWA Metaltech Co., Ltd. (DOWA Holdings Company Limited)
• Original Assignee: Dowa Mining Company Limited
• Inventors: Namioka, Makoto, Osanai, Hideyo, Ibaraki, Susumu, Iyoda, Ken
• Primary Examiner(s): Reichard; Dean A.
• Assistant Examiner(s): NGUYEN, HOA CAO
• Application Number:
  US10/747,837
• Publication Number:
  US 20040144561A1
• Time in Patent Office: 1,324 Days
• Field of Search: 361/704, 361/707, 361/719, 361/720, 174/252, 174/250, 174255-257, 29830-832, 298/40, 298/42, 298/43, 428/210, 428/545, 428/615, 428/627, 257/706, 257/753, 228/121, 228/180.21
• US Class Current: 174/252
• CPC Class Codes: H01L 23/13 characterised by the shape
• CPC Class Codes: H01L 23/3735 Laminates or multilayers, e.g. direct bond copper ceramic substrates
• 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 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/3511 Warping
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 3/0058 Laminating printed circuit boards onto other substrates, e.g. metallic substrates H05K1/0281 takes precedence
• CPC Class Codes: Y10T 428/12007 Component of composite having metal continuous phase interengaged with nonmetal continuous phase
• CPC Class Codes: Y10T 428/12493 Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
• CPC Class Codes: Y10T 428/24926 including ceramic, glass, porcelain or quartz layer

Abstract

There is provided a metal/ceramic bonding substrate capable of preventing the reverse thereof from greatly warping so as to be concave even if it is heated for soldering. In the metal/ceramic bonding substrate, a metal circuit plate 12 is bonded to one side of a ceramic substrate 10, and a heat sink plate (metal base plate) 14 is bonded to the other side thereof. On the heat sink plate 14, a work-hardened layer 16 is formed by shot peening. On the metal circuit plate 12 of the metal/ceramic bonding substrate, semiconductor chips (Si chips) 18 are soldered (solder layer 20). Then, a power module is produced by a predetermined process. On the reverse (the side of the work-hardened layer 16) of the power module, a radiating fin 26 is mounted via a thermal grease 24 by means of screws 22 or the like.

Claims

1. A metal/ceramic bonding substrate comprising:

a ceramic substrate;

a metal circuit plate bonded to one side of said ceramic substrate; and

a heat sink plate of a metal, one surface of the heat sink plate being bonded to the other side of said ceramic substrate, and another surface of the heat sink plate comprising a work-hardened surface of said metal of said heat sink plate for mounting thereon a radiating or cooling means.

2. A metal/ceramic bonding substrate as set forth in claim 1, wherein said work-hardened layer is formed by shot peening.

3. A metal/ceramic bonding substrate as set forth in claim 1, wherein a warpage of the another surface of said heat sink plate is −

200 micrometers or more, assuming that said warpage is a difference in height between a center and edge of the another surface of said heat sink plate and is positive (+) when the other side of said heat sink plate warps so as to be convex and negative (−

) when the another surface of said heat sink plate warps so as to be concave.

4. A metal/ceramic bonding substrate as set forth in claim 1, wherein a warpage of the another surface of said heat sink plate is in the range of from −

100 to +500 micrometers, assuming that said warpage is a difference in height between a center and edge of the another surface of said heat sink plate and is positive (+) when the another surface of said heat sink plate warps so as to be convex and negative (−

) when the another surface of said heat sink plate warps so as to be concave.

5. A metal/ceramic bonding substrate as set forth in claim 1, wherein a warpage of the another surface of said heat sink plate is in the range of from 0 to +200 micrometers, assuming that said warpage is a difference in height between a center and edge of the another surface of said heat sink plate and is positive (+) when the another surface of said heat sink plate warps so as to be convex and negative (−

) when the another surface of said heat sink plate warps so as to be concave.

6. A metal/ceramic bonding substrate as set forth in claim 1, wherein said metal circuit plate and said heat sink plate contact said ceramic substrate to be bonded directly to said ceramic substrate.

7. A metal/ceramic bonding substrate as set forth in claim 6, wherein said metal is aluminum or an aluminum alloy.

8. A power module comprising:

a metal/ceramic bonding substrate as set forth in claim 1; and

a semiconductor chip soldered on said metal circuit plate of said metal/ceramic bonding substrate.

9. A metal/ceramic bonding substrate as set forth in claim 1, wherein said metal is aluminum or an aluminum alloy.

10. A metal/ceramic bonding substrate as set forth in claim 1, wherein said metal is copper.