Patent US5085923A successfully refreshed from Google Patents.
US5085923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat-conductive aluminum nitride sintered body and method of manufacturing the same
Assignee: Sumitomo Electric Industries Ltd
•
Filing: 1991-04-17
•
Granted: 1992-02-04
•
Expires: 2011-04-17
Abstract
Abstract An aluminum nitride sintered body is mainly composed of aluminum nitride, contains 0.01 to 1.0 percent by weight of a rare earth element and 0.001 to 0.5 percent by weight of oxygen, and has thermal conductivity of at least 180 W/mK. According to a method of manufacturing such an aluminum nitride sintered body, aluminum nitride powder (201) is first prepared. At least one compound (203) containing a rare earth element is added to the aluminum nitride powder (201) to contain 0.01 to 1.0 percent by weight, in rare earth element conversion, of the compound, to be homogeneously mixed with each other. A formed body obtained by forming such mixed powder is sintered in a non-oxidizing atmosphere containing nitrogen at a temperature of 1500 to 2200° C.
Inventors
- 👤 Akira Yamakawa
- 👤 Masaya Miyake
- 👤 Hitoyuki Sakanoue
- 👤 Hisao Takeuchi
- 👤 Koichi Sogabe
- 👤 Akira Sasame
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:54
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692; C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/581; C04B35/622; C04B35/64; C04B37/00; C04B37/02; C04B37/023; C04B37/026; H10W99/00; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3205; C04B2235/3208; C04B2235/3224; C04B2235/3225; C04B2235/3229; C04B2235/38; C04B2235/3852; C04B2235/3865; C04B2235/3895; C04B2235/44; C04B2235/449; C04B2235/50; C04B2235/54; C04B2235/5418; C04B2235/5445; C04B2235/65; C04B2235/656; C04B2235/6567; C04B2235/658; C04B2235/6583; C04B2235/70; C04B2235/72; C04B2235/721; C04B2235/723; C04B2235/74; C04B2235/76; C04B2235/761; C04B2235/77; C04B2235/80; C04B2235/85; C04B2235/96; C04B2235/9607; C04B2235/963; C04B2237/00; C04B2237/02; C04B2237/12; C04B2237/122; C04B2237/123; C04B2237/30; C04B2237/32; C04B2237/36; C04B2237/366; C04B2237/40; C04B2237/403; C04B2237/407; C04B2237/50; C04B2237/55; C04B2237/72; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H10W70/68; H10W70/682; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
126 words
A circuit board, comprising a substrate made of an aluminum nitride sintered body, a circuit pattern on at least a major surface of said substrate, said circuit pattern including a conductive paste, said aluminum nitride sintered body comprising 0.01 to 0.8 wt% of a rare earth element, 0.2 to 0.5 wt% of oxygen, 0.001 to 0.1 wt% of carbon, the remainder being aluminum nitride consisting essentially of aluminum nitride particles and intergranular phases existing between said aluminum nitride particles, said intergranular phases having a size not more than one micron, and wherein the intergranular phases contain at least two elements selected from the group consisting of rare earth elements, aluminum, oxygen, nitrogen and carbon, said substrate having a surface roughness of not more than 5 microns.
Claim 2
Dependent Claim
126 words
A circuit board, comprising a substrate made of an aluminum nitride sintered body, a circuit pattern on at least a major surface of said substrate, said circuit pattern including a conductive paste, said aluminum nitride sintered body comprising 0.01 to 0.8 wt% of a rare earth element, 0.2 to 0.5 wt% of oxygen, 0.001 to 0.1 wt% of carbon, the remainder being aluminum nitride consisting essentially of aluminum nitride particles and intergranular phases existing between said aluminum nitride particles, said intergranular phases having a size not more than one micron, and wherein the intergranular phases contain at least two elements selected from the group consisting of rare earth elements, aluminum, oxygen, nitrogen and carbon, said substrate having a surface roughness of not more than 5 microns.
Claim 3
Dependent Claim
26 words
The circuit board of claim 1, wherein said conductive paste contains at least one metal selected from the group consisting of silver, gold, palladium, and copper.
Claim 4
Dependent Claim
22 words
The circuit board of claim 1, wherein said conductive paste contains a metal selected from the group consisting of tungsten and molybdenum.
Claim 5
Dependent Claim
125 words
A semiconductor device, comprising a substrate made of an aluminum nitride sintered body comprising 0.01 to 0.8 wt% of a rare earth element, 0.2 to 0.5 wt% of oxygen, 0.001 to 0.1 wt% of carbon, the remainder being aluminum nitride consisting essentially of aluminum nitride particles and intergranular phases existing between said aluminum nitride particles, said intergranular phases having a size not more than one micron, and wherein the intergranular phases contain at least two elements selected from the group consisting of rare earth elements, aluminum, oxygen, nitrogen and carbon, said substrate having a surface roughness of not more than 5 microns, a semiconductor element carried on a major surface of said substrate, and a lead frame joined to said major surface of said substrate.
Claim 6
Dependent Claim
125 words
A semiconductor device, comprising a substrate made of an aluminum nitride sintered body comprising 0.01 to 0.8 wt% of a rare earth element, 0.2 to 0.5 wt% of oxygen, 0.001 to 0.1 wt% of carbon, the remainder being aluminum nitride consisting essentially of aluminum nitride particles and intergranular phases existing between said aluminum nitride particles, said intergranular phases having a size not more than one micron, and wherein the intergranular phases contain at least two elements selected from the group consisting of rare earth elements, aluminum, oxygen, nitrogen and carbon, said substrate having a surface roughness of not more than 5 microns, a semiconductor element carried on a major surface of said substrate, and a lead frame joined to said major surface of said substrate.
Claim 7
Dependent Claim
22 words
The semiconductor device of claim 4, further comprising heat sink means joined to said substrate for removing heat from said semiconductor device.
Claim 8
Dependent Claim
19 words
The semiconductor device of claim 4, further comprising a stress relaxation member joining said lead frame to said substrate.
References Cited (Backward Citations)
JPS6071576A
Cited
JPS6071575A
Cited
JPS6096578A
Cited
JPS60127267A
Cited
US4578232A
Cited
JPS61155263A
Cited
US4961987A
Cited
DE3627317A1
Cited
JPS6241766A
Cited
US4897372A
Cited
US4770953A
Cited
US4847221A
Cited
US4906511A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-02-03 | 1995-08-05 | 1996-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-03 | 1999-08-05 | 2000-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-03 | 2003-08-05 | 2004-02-04 | $7700.00 | Window Closed / Lapsed |