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US4698320A
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Aluminum nitride sintered body
Assignee: Toshiba Corp
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Filing: 1985-01-30
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Granted: 1987-10-06
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Expires: 2005-01-30
Abstract
Abstract An aluminum nitride sintered body prepared by a process comprising adding to a principal component of aluminum nitride an additional component of at least one of fluorides of alkaline earth metals selected from the group consisting of calcium (Ca), strontium (Sr) and barium (Ba) or at least one of fluorides of rare earth elements added in an amount of 0.01 to 20% by weight, followed by sintering.
Inventors
- 👤 Mituo Kasori
- 👤 Kazuo Shinozaki
- 👤 Kazuo Anzai
- 👤 Takeshi Takano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:30
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/581
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
98 words
An aluminum nitride sintered body prepared by a process comprising the steps of (1) providing a mixture which consists essentially of aluminum nitride and a sintering aid which consists essentially of at least one fluoride of an alkaline earth metal selected from the group consisting of calcium, strontium and barium or at least one fluoride of a rare earth in an amount of 0.01 to 20% by weight, based on the total amount of said component; and (2) sintering said mixture to produce an aluminum nitride sintered body having a thermal conductivity of at least about 40 W/m.k.
Claim 2
Dependent Claim
98 words
An aluminum nitride sintered body prepared by a process comprising the steps of (1) providing a mixture which consists essentially of aluminum nitride and a sintering aid which consists essentially of at least one fluoride of an alkaline earth metal selected from the group consisting of calcium, strontium and barium or at least one fluoride of a rare earth in an amount of 0.01 to 20% by weight, based on the total amount of said component; and (2) sintering said mixture to produce an aluminum nitride sintered body having a thermal conductivity of at least about 40 W/m.k.
Claim 3
Dependent Claim
16 words
The aluminum nitride sintered body according to claim 1, wherein said sintering aid is calcium fluoride.
Claim 4
Dependent Claim
16 words
The aluminum nitride sintered body according to claim 1, wherein said sintering aid is yttrium fluoride.
Claim 5
Dependent Claim
31 words
The aluminum nitride sintered body according to claim 1, wherein step (2) consists essentially of sintering said mixture at about 1600° C. to 1850° C. in a N 2 gas atmosphere.
Claim 6
Dependent Claim
24 words
The aluminum nitride sintered body according to claim 4, wherein said sintering in a N 2 gas atmosphere is about 2 hours in duration.
Claim 7
Dependent Claim
24 words
The aluminum nitride sintered body according to claim 1, wherein step (2) consists of hot pressing said mixture at about 1600° to 1800° C.
Claim 8
Dependent Claim
19 words
The aluminum nitride sintered body according to claim 6, wherein said hot pressing is about 1 hour in druation.
Claim 9
Dependent Claim
31 words
The aluminum nitride sintered body according to claim 1, wherein said sintering aid consists essentially of at least one from the group consisting of calcium fluoride, strontium fluoride and barium fluoride
Claim 10
Dependent Claim
98 words
A process for preparing an aluminum nitride sintered body, comprising the steps of (1) providing a mixture which consists essentially of aluminum nitride and a sintering aid which consists essentially of at least one fluoride of an alkaline earth metal selected from the group consisting of calcium, strontium and barium or at least one fluoride of a rare earth element in an amount of 0.01 to 20% by weight, based on the total amount of said component; and (2) sintering said mixture to produce an aluminum nitride sintered body having a thermal conductivity of at least 40 W/m.k.
Claim 11
Dependent Claim
98 words
A process for preparing an aluminum nitride sintered body, comprising the steps of (1) providing a mixture which consists essentially of aluminum nitride and a sintering aid which consists essentially of at least one fluoride of an alkaline earth metal selected from the group consisting of calcium, strontium and barium or at least one fluoride of a rare earth element in an amount of 0.01 to 20% by weight, based on the total amount of said component; and (2) sintering said mixture to produce an aluminum nitride sintered body having a thermal conductivity of at least 40 W/m.k.
Claim 12
Dependent Claim
13 words
The process according to claim 9, wherein said sintering aid is calcium fluoride.
Claim 13
Dependent Claim
13 words
The process according to claim 9, wherein said sintering aid is yttrium fluoride.
Claim 14
Dependent Claim
27 words
The process according to claim 9, wherein step (2) consists essentially of sintering said mixture at about 1600° to 1850° C. in a N 2 gas atmosphere.
Claim 15
Dependent Claim
21 words
The process according to claim 12, wherein said sintering in a N 2 gas atmosphere is about 2 hours in duration.
Claim 16
Dependent Claim
22 words
The process according to claim 9, wherein step (2) consists essentially of hot pressing said mixture at about 1600° to 1800° C.
Claim 17
Dependent Claim
16 words
A process according to claim 14, wherein said hot pressing is about 1 hour in duration.
Claim 18
Dependent Claim
28 words
A process according to claim 9, wherein said sintering aid consists essentially of at least one from the group consisting of calcium fluoride, strontium fluoride and barium fluoride
References Cited (Backward Citations)
US2480473A
Cited
GB1001867A
Cited
US3238018A
Cited
US3503787A
Cited
US4519966A
Cited
US4547471A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-05 | 1991-04-06 | 1991-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-05 | 1995-04-06 | 1995-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-05 | 1999-04-06 | 1999-10-06 | $7700.00 | Window Closed / Lapsed |