Patent US3857923A successfully refreshed from Google Patents.
US3857923A
Expired / Lapsed
US
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Mullite package for integrated circuit devices
Assignee: International Business Machines Corp
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Filing: 1972-06-20
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Granted: 1974-12-31
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Expires: 1992-06-20
Abstract
Abstract A process for forming a substantially stoichiometric high density, high purity mullite compound (3Al2O3.2SiO2) capable of being fired in a single step.
Inventors
- 👤 R Gardner
- 👤 D Wilcox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:42
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/36; C01B33/38; C01B33/42; C01B33/26; C01B33/40; C01B33/46; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; H; H10; H10W; H10W99/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
106 words
A METHOD OF FABRICATING A SUBSTANTIALLY STOICHIOMETRIC HIGH DENSITY AND HIGH PURITY MULLITE COMPOUND COMPRISING THE STEPS OF: A. FORMING A PARTICULATE MIXTURE OF 3AL2O3 + 2SIO2 BY THE HYDROGEN FLAME PYROLYSIS OF A SOLUTION OF 6ALCL3 AND 2SICL4; B. FORMING A LIQUID DISPERSION OF SAID MIXTURE WITH A BINDER AND A SOLVENT SUCH THAT SAID BINDER COATS THE PARTICLES OF SAID MIXTURE; C. REMOVING SAID SOLVENT FROM SAID MIXTURE; AND D. HEATING SAID MIXTURE TO A TEMPERATURE ABOVE ABOUT 900* C SO AS TO REMOVE SAID BINDER, REACT SAID AL2O3 AND SIO2 TO FORM A 3AL2O3.SIO2 MULLITE COMPOUND, AND SINTER SAID COMPOUND TO REMOVE VOIDS.
Claim 2
Independent Claim
106 words
A METHOD OF FABRICATING A SUBSTANTIALLY STOICHIOMETRIC HIGH DENSITY AND HIGH PURITY MULLITE COMPOUND COMPRISING THE STEPS OF: A. FORMING A PARTICULATE MIXTURE OF 3AL2O3 + 2SIO2 BY THE HYDROGEN FLAME PYROLYSIS OF A SOLUTION OF 6ALCL3 AND 2SICL4; B. FORMING A LIQUID DISPERSION OF SAID MIXTURE WITH A BINDER AND A SOLVENT SUCH THAT SAID BINDER COATS THE PARTICLES OF SAID MIXTURE; C. REMOVING SAID SOLVENT FROM SAID MIXTURE; AND D. HEATING SAID MIXTURE TO A TEMPERATURE ABOVE ABOUT 900* C SO AS TO REMOVE SAID BINDER, REACT SAID AL2O3 AND SIO2 TO FORM A 3AL2O3.SIO2 MULLITE COMPOUND, AND SINTER SAID COMPOUND TO REMOVE VOIDS.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the particles in step a have a particle size of from .03 to .1 micron.
Claim 4
Dependent Claim
11 words
The method of claim 1 wherein said binder is a polymer.
Claim 5
Dependent Claim
13 words
The method of claim 3 wherein a plasticizer is mixed with said polymer.
Claim 6
Dependent Claim
15 words
The method of claim 4 wherein said polymer is polyvinylbutyral and said plasticizer is dioctylphthalate.
Claim 7
Dependent Claim
39 words
The method of claim 4 wherein in step c said liquid dispersion is cast and dried in the form of sheet material such that said method forms a sintered mullite body suitable for use as an integrated circuit substrate.
Claim 8
Dependent Claim
27 words
The method of claim 6 wherein said sheet material is heated in step d to a maximum temperature in the range of 1,500* - 1, 600* C.
Claim 9
Dependent Claim
21 words
The method of claim 7 wherein a plurality of said sheet material is laminated prior to being heated in step d.
References Cited (Backward Citations)
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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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |