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Patent US4528212A successfully refreshed from Google Patents.
US4528212A
Expired / Lapsed
US
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Coated ceramic substrates for mounting integrated circuits
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1982-07-22
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Granted: 1985-07-09
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Expires: 2002-07-22
Abstract
Abstract Coated ceramic substrates or structures having a barrier layer against alpha-particle radiation and integrated circuits prepared therefrom. Ceramic surfaces having reduced or modified surface roughness are also provided.
Inventors
- 👤 James A. Cairns
- 👤 James F. Ziegler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:38
CPC Classifications
H; H10; H10W; H10W42/00; H10W42/20; H10W42/25; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K3/00; H05K3/38; H10W72/00; H10W72/071; H10W72/072; H10W72/07251; H10W72/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
123 words
A method of modifying and controlling the surface texture of a ceramic surface on an integrated circuit chip carrier, said method comprising the steps of: coating the ceramic surface of an integrated circuit chip carrier to be modified with a ceramic precursor liquid dispersion of particulates wherein the particulates have a particle size in the range of from about 0.05 to about 5 μm, the surface texture of the modified surface being controlled by providing that the particle size of the particulates is within said range of from about 0.05 to about 5 μm; removing said liquid from said dispersion of particulates on said ceramic surface; firing said coating to obtain a stable union or bond of said coating with said ceramic surface.
Claim 2
Independent Claim
123 words
A method of modifying and controlling the surface texture of a ceramic surface on an integrated circuit chip carrier, said method comprising the steps of: coating the ceramic surface of an integrated circuit chip carrier to be modified with a ceramic precursor liquid dispersion of particulates wherein the particulates have a particle size in the range of from about 0.05 to about 5 μm, the surface texture of the modified surface being controlled by providing that the particle size of the particulates is within said range of from about 0.05 to about 5 μm; removing said liquid from said dispersion of particulates on said ceramic surface; firing said coating to obtain a stable union or bond of said coating with said ceramic surface.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the liquid dispersion is a sol.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the particulates are aggregated colloidal particles.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein the particulates are substantially unaggregated colloidal particles.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein the coating is substantially free of alpha-particle emitting substances.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein the ceramic precursor liquid dispersion is sol of a refractory oxide.
Claim 8
Dependent Claim
24 words
The method of claim 6 wherein said refractory oxide is selected from the group consisting of alumina, ceria, silica, zirconia, titania and mixtures thereof.
Claim 9
Dependent Claim
11 words
The method of claim 7 wherein said refractory oxide is alumina.
References Cited (Backward Citations)
US4297246A
Cited
US4230773A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-08 | 1989-01-07 | 1989-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-08 | 1993-01-07 | 1993-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-08 | 1997-01-07 | 1997-07-09 | $7700.00 | Window Closed / Lapsed |