US4873151A
Expired / Lapsed
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Aluminum nitride circuit substrate
Assignee: Toshiba Corp
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Filing: 1987-07-08
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Granted: 1989-10-10
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Expires: 2007-07-08
Abstract
Abstract Disclosed is an aluminum nitride circuit substrate comprising an aluminum nitride plate and a conductive material bonded to the aluminum nitride plate through a metallized layer formed on the bonding surface of the aluminum nitride plate, the conductive material being of a metallic material which has a thermal expansion coefficient of 2×10 -6 to 6×10 -6 /°C. The aluminum nitride circuit substrate according to this invention is free from the generation of crack caused by the difference of the thermal expansion coefficients of AlN plate and a conductive material bonded to the AlN plate to improve the reliability of the elements.
Inventors
- 👤 Hideki Sato
- 👤 Nobuyuki Mizunoya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:29
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/62; H10W70/66; C; C04; C04B; C04B37/00; C04B37/02; C04B37/023; C04B37/026; H10W72/00; H10W72/30; C04B2237/00; C04B2237/02; C04B2237/12; C04B2237/122; C04B2237/123; C04B2237/124; C04B2237/125; C04B2237/126; C04B2237/30; C04B2237/32; C04B2237/36; C04B2237/366; C04B2237/40; C04B2237/50; C04B2237/72; C04B2237/86; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K3/00; H05K3/22; H05K3/24; H05K3/244; H10W72/851; H10W72/874; H10W72/884; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12576; Y10T428/12771; Y10T428/12806; Y10T428/12819; Y10T428/12826; Y10T428/1284; Y10T428/12861; Y10T428/12903; Y10T428/12944
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
71 words
An aluminum nitride circuit substrate comprising: an aluminum nitride plate comprising a bonding surface; and a conductive material having a thermal expansion coefficient substantially similar to that of AlN bonded to said aluminum nitride plate through a metallized layer fomred on the bonding surface of the aluminum nitride plate, said conductive material being of a metallic material which has a thermal expansion coefficient of 2×10 -6 to 6×10 -6 /° C.
Claim 2
Dependent Claim
71 words
An aluminum nitride circuit substrate comprising: an aluminum nitride plate comprising a bonding surface; and a conductive material having a thermal expansion coefficient substantially similar to that of AlN bonded to said aluminum nitride plate through a metallized layer fomred on the bonding surface of the aluminum nitride plate, said conductive material being of a metallic material which has a thermal expansion coefficient of 2×10 -6 to 6×10 -6 /° C.
Claim 3
Dependent Claim
25 words
The aluminum nitride circuit substrate according to claim 1, wherein said thermal expansion coefficient is in the range of 4×10 -6 to 5×10 -6 /°C.
Claim 4
Dependent Claim
18 words
The aluminum nitride circuit substrate according to claim 1, wherein said conductive material is a plate-like lead frame.
Claim 5
Dependent Claim
29 words
The aluminum nitride circuit substrate according to claim 3, wherein the bonding area of the aluminum nitride and the lead frame is not less than 4 mm 2 .
Claim 6
Dependent Claim
29 words
The aluminum nitride circuit substrate according to claim 4, wherein the bonding area of the aluminum nitride and the lead frame is not less than 8 mm 2 .
Claim 7
Dependent Claim
29 words
The aluminum nitride circuit substrate according to claim 5, wherein the bonding area of the aluminum nitride and the lead frame is not less than 16 mm 2 .
Claim 8
Dependent Claim
23 words
The aluminum nitride circuit substrate according to claim 1, wherein said metallized layer is selected from the group consisting of molybdenum and tungsten.
Claim 9
Dependent Claim
67 words
The aluminum nitride circuit substrate according to claim 1, wherein said conductive material is at least one selected from the group consisting of molybdenum, tungsten, a molybdenum series alloy, a tungsten series alloy, a nickel series alloy, a chromium series alloy, a copper series alloy, copper, a clad metal of an Fe-Ni-Co alloy for hermetic sealing and copper, a Mo-Cu clad metal and a W-Cu clad metal.
Claim 10
Dependent Claim
15 words
The aluminum nitride circuit substrate according to claim 8, wherein said conductive material is molybdenum.
Claim 11
Dependent Claim
16 words
The aluminum nitride circuit substrate according to claim 8, wherein said conductive material is Invar steel.
Claim 12
Dependent Claim
66 words
The aluminum nitride circuit substrate according to claim 1, wherein said metallized layer is a conductive metallized layer containing: (i) at least one element selected from the first group consisting of molybdenum, tungsten and tantalum; and (ii) at least one element selected from the second group consisting of IIb group element, IIIa and IIIb group elements, IVb group elements, and rare-earth elements in periodic law table.
Claim 13
Dependent Claim
19 words
The aluminum nitride circuit substrate according to claim 11, wherein said second group consists of said IIb group elements.
Claim 14
Dependent Claim
21 words
The aluminum nitride circuit substrate according to claim 11, wherein said second group consists of said IIIa and IIIb group elements.
Claim 15
Dependent Claim
20 words
The aluminum nitride circuit substrate according to claim 11, wherein said second group consists of said rare earth group elements.
Claim 16
Dependent Claim
19 words
The aluminum nitride circuit substrate according to claim 11, wherein said second group consists of said IVb group elements.
Claim 17
Dependent Claim
29 words
The aluminum nitride circuit substrate according to claim 11, wherein component (ii) is selected from the group consisting of Al, Ti, Zr, Hf, Y, Ce, Dy, Th and Sm.
Claim 18
Dependent Claim
17 words
The aluminum nitride circuit substrate according to claim 1, wherein the conductive material is a lead frame.
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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) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |