Patent US4869925A successfully refreshed from Google Patents.
US4869925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preparing aluminum nitride and its sinter
Assignee: Mitsui Toatsu Chemicals Inc
•
Filing: 1988-07-29
•
Granted: 1989-09-26
•
Expires: 2008-07-29
Abstract
Abstract A method for preparing high-purity aluminum nitride having high thermal conductivity and heat resistance for aluminum nitride substrates, which comprises the steps of reacting an organic aluminum compound with an aminotriazine in a solvent to obtain an aluminum nitride precursor, separating the precursor from the solvent, and heating the precursor at a temperature of 600° C. or more in a reducing atmosphere and/or a non-oxidizing atmosphere. An aluminum nitride sinter is prepared by, if necessary, adding a sintering auxiliary to the above aluminum nitride powder, molding the powder into a desired shape, and then sintering the molded material at a temperature of 1,600° to 2,000° C. in a non-oxidizing atmosphere.
Inventors
- 👤 Atsuhiko Hiai
- 👤 Kazuo Wakimura
- 👤 Masao Tanaka
- 👤 Takao Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:14
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/06; C01B21/072; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/581; C01P; C01P2006/00; C01P2006/12; C01P2006/80; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
42 words
A method for preparing aluminum nitride which comprises the steps of reacting an organic aluminum compound with an aminotriazine in a solvent to obtain an aluminum nitride precursor, separating the aluminum nitride precursor from the solvent, and heating/calcining the aluminum nitride precursor.
Claim 2
Independent Claim
42 words
A method for preparing aluminum nitride which comprises the steps of reacting an organic aluminum compound with an aminotriazine in a solvent to obtain an aluminum nitride precursor, separating the aluminum nitride precursor from the solvent, and heating/calcining the aluminum nitride precursor.
Claim 3
Dependent Claim
55 words
A method for preparing aluminum nitride according to claim 1 wherein the organic aluminum compound is an alkylaluminum compound represented by the general formula R.sub.n.Al.X.sub.3-n wherein R is a lower alkyl group having 1 to 10 carbon atoms, n is 1, 1.5, 2 or 3, and X is a hydrogen atom or a halogen atom.
Claim 4
Dependent Claim
35 words
A method for preparing aluminum nitride according to claim 1, wherein the molar ratio of the number of the amino groups in the aminotriazine compound to the organic aluminum compound is from 0.1 to 100.
Claim 5
Dependent Claim
19 words
A method for preparing aluminum nitride according to claim 3, wherein the molar ratio is from 1 to 10.
Claim 6
Dependent Claim
29 words
A method for preparing aluminum nitride according to claim 1 wherein the solvent is an organic solvent which is inert with respect to the organic aluminum and the aminotriazine.
Claim 7
Dependent Claim
38 words
A method for preparing aluminum nitride according to claim 1, wherein the aminotriazine is dispersed in the solvent to form a slurry and this slurry is fed to a reaction zone for reaction with the organic aluminum compound.
Claim 8
Dependent Claim
28 words
A method for preparing aluminum nitride according to claim 1, wherein the reaction with the organic aluminum compound is performed at a temperature of 10° to 300° C.
Claim 9
Dependent Claim
20 words
A method for preparing aluminum nitride according to claim 1 wherein the aluminum nitride precursor is obtained as a precipitate.
Claim 10
Dependent Claim
26 words
A method for preparing aluminum nitride according to claim 8 wherein the aluminum nitride precursor precipitate is separated from the solvent by a solid-liquid separating operation.
Claim 11
Dependent Claim
24 words
A method for preparing aluminum nitride according to claim 8 wherein the separated aluminum nitride precursor precipitate is heated/calcined in a reducing gas atmosphere.
Claim 12
Dependent Claim
24 words
A method for preparing aluminum nitride according to claim 8 wherein the separated aluminum nitride precursor precipitate is heated/calcined in an inert gas atmosphere.
Claim 13
Dependent Claim
32 words
A method for preparing aluminum nitride according to claim 8 wherein the separated aluminum nitride precursor precipitate is heated/calcined first in a reducing gas atmosphere and thereafter in an inert gas atmosphere.
Claim 14
Dependent Claim
31 words
A method for preparing aluminum nitride according to claim 1 wherein the heating/calcination operation of the separated aluminum nitride precursor is carried out at a temperature of 600° C. or more.
Claim 15
Dependent Claim
26 words
The method of claim 1, further comprising the step of molding the aluminum nitride powder further into a desired shape, and then sintering the thus-shaped material.
Claim 16
Dependent Claim
33 words
A method for preparing a sinter of aluminum nitride according to claim 14 wherein the aluminum nitride powder is sintered at a sintering temperature of 1,600° to 2,000° C. in a non-oxidizing atmosphere.
Claim 17
Dependent Claim
130 words
A method for preparing an aluminum nitride sinter, wherein the aluminum nitride is prepared according to the method of claim 2; wherein the molar ratio of the number of the amino groups in the aminotriazine compound to the organic aluminum compound is from 1 to 10; wherein the aminotriazine is dispersed in the solvent to form a slurry and this slurry is fed to a reaction zone for reaction with the organic aluminum compound; wherein the aluminum nitride precursor is obtained as a precipitate, which is separated from the solvent prior to the heating/calcinating step; and wherein the heating/calcinating operation of the separated aluminum nitride precursor is carried out at a temperature of 600° C. or more, first in a reducing gas atmosphere and thereafter in an inert gas atmosphere.
Claim 18
Dependent Claim
36 words
A method for preparing an aluminum nitride sinter according to claim 16, wherein prior to or as part of the sintering step, the aluminum nitride is molded as a coating on an alumina circuit board substrate.
Claim 19
Dependent Claim
23 words
A method for preparing an aluminum nitride sinter according to claim 17, wherein the sintering operation is carried out in a non-oxidizing atmosphere.
References Cited (Backward Citations)
US4783430A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |