Patent US4959507A successfully refreshed from Google Patents.
US4959507A
Expired / Lapsed
US
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Bonded ceramic metal composite substrate, circuit board constructed therewith and methods for production thereof
Assignee: Toshiba Corp
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Filing: 1989-04-25
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Granted: 1990-09-25
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Expires: 2009-04-25
Abstract
Abstract A bonded ceramic-metal composite substrate comprising a ceramic substrate having opposite surfaces and a copper sheet having a face directly bonded to one of the surfaces of the ceramic substrate, wherein the median surface roughness (R a ) of the outer surface of the copper sheet is not greater than 3 μm, and the maximum surface roughness (R max ) of the outer surface of the copper sheet is not greater than 18 μm. The invention improves the manufacturing reliability of various electronic devices such as semiconductor modules.
Inventors
- 👤 Tadashi Tanaka
- 👤 Kazuo Matsumura
- 👤 Hiroshi Komorita
- 👤 Nobuyuki Mizunoya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:40
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/20; H10W40/25; H10W40/255; H05; H05K; H05K3/00; H05K3/38; H10W70/00; H10W70/01; H10W70/04; H10W70/047; H10W70/60; H10W70/62; H10W70/66; H10W72/00; H10W72/50; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2201/09; H05K2201/09009; H05K2201/09118; H10W72/531; H10W72/5363; H10W72/551; H10W72/552; H10W72/5524; H10W90/00; H10W90/701; H10W90/751; H10W90/754; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49155; Y10T428/00; Y10T428/12; Y10T428/12472; Y10T428/12993
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
74 words
A bonded ceramic-metal composite substrate comprising a ceramic substrate having opposite surfaces and a copper sheet having one face directly bonded to one of the surfaces of the ceramic substrate, wherein the median surface roughness (R a ) of the outer surface of the copper sheet is not greater than 3 μm, and the maximum surface roughness (R max ) of the outer surface of the copper sheet is not greater than 18 μm.
Claim 2
Dependent Claim
74 words
A bonded ceramic-metal composite substrate comprising a ceramic substrate having opposite surfaces and a copper sheet having one face directly bonded to one of the surfaces of the ceramic substrate, wherein the median surface roughness (R a ) of the outer surface of the copper sheet is not greater than 3 μm, and the maximum surface roughness (R max ) of the outer surface of the copper sheet is not greater than 18 μm.
Claim 3
Dependent Claim
54 words
A bonded ceramic metal composite substrate according to claim 1, wherein the median surface roughness (R a ) of the outer surface of the copper sheet is not greater than 1 μm, and the maximum surface roughness (R max ) of the outer surface of the copper sheet is not greater than 8 μm.
Claim 4
Dependent Claim
26 words
A bonded ceramic-metal composite substrate according to claim 1, wherein the copper sheet has an oxygen content in the range from about 100 to 3000 ppm.
Claim 5
Dependent Claim
147 words
A circuit board comprising: (a) a bonded ceramic metal composite substrate comprising a ceramic substrate having opposite surfaces and a copper sheet having opposite faces, one of which faces is directly bonded to one of the surfaces of the ceramic substrate and the other of which faces comprises at least one mounting area and at least one electrode area, wherein the median surface roughness (R a ) of the outer surface of said at least one mounting area of the copper sheet is not greater than 3 μm, and the maximum surface roughness (R max ) of the outer surface of said at least one mounting area is not greater than 18 μm; (b) at least one electrical element mounted on the mounting area of said copper sheet, and (c) at least one bonding wire electrically connecting said at least one electrical element with said electrode area.
Claim 6
Dependent Claim
147 words
A circuit board comprising: (a) a bonded ceramic metal composite substrate comprising a ceramic substrate having opposite surfaces and a copper sheet having opposite faces, one of which faces is directly bonded to one of the surfaces of the ceramic substrate and the other of which faces comprises at least one mounting area and at least one electrode area, wherein the median surface roughness (R a ) of the outer surface of said at least one mounting area of the copper sheet is not greater than 3 μm, and the maximum surface roughness (R max ) of the outer surface of said at least one mounting area is not greater than 18 μm; (b) at least one electrical element mounted on the mounting area of said copper sheet, and (c) at least one bonding wire electrically connecting said at least one electrical element with said electrode area.
Claim 7
Dependent Claim
60 words
A circuit board according to claim 4, wherein the median surface roughness (R a ) of the outer surface of said at least one mounting area on the coppersheet is not greater than 1 μm, and the maximum surface roughness (R max ) of the outer surface of said at least one mounting area is not greater than 8 μm.
Claim 8
Dependent Claim
24 words
A circuit board according to claim 4, wherein said copper sheet has an oxygen content in the range from about 100 to 3,000 ppm.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-24 | 1994-03-26 | 1994-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-24 | 1998-03-26 | 1998-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-24 | 2002-03-26 | 2002-09-25 | $7700.00 | Window Closed / Lapsed |