Patent US4440828A successfully refreshed from Google Patents.
US4440828A
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Substrate for a microwave electronic circuit and a method for the making of said substrate
Assignee: Thales SA
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Filing: 1983-04-14
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Granted: 1984-04-03
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Expires: 2003-04-14
Abstract
Abstract The substrate is formed by a plate of boron nitride having a composition of 42% B, 53.5% N 2 , containing between 1.5 and 2.5% O 2 , and 1.5% Ca. The surface is increased in hardness and made non-friable by deposition of a glass film to a depth within the range of 10 to 15 microns. This deposit permits surface metallization and ensures cohesion of the boron nitride grains.
Inventors
- 👤 Jean-Claude Resneau
- 👤 Pierre Roset
- 👤 Jean Doyen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:48
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692; H10W99/00; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
83 words
A substrate for a microwave circuit, comprising a plate comprising fused grains of boron nitride comprising 42% boron, 53.5% nitride, between 1.5 and 2.5% oxygen and 1.5% calcium having two large faces, and a thin glass film deposited at least on one face of said faces, thereby permitting surface metallization of said face and ensuring cohesion of the grains of born nitride wherein said glass film has a dielectric constant substantially equal to the dielectric constant of quartz or of said boron nitride.
Claim 2
Dependent Claim
83 words
A substrate for a microwave circuit, comprising a plate comprising fused grains of boron nitride comprising 42% boron, 53.5% nitride, between 1.5 and 2.5% oxygen and 1.5% calcium having two large faces, and a thin glass film deposited at least on one face of said faces, thereby permitting surface metallization of said face and ensuring cohesion of the grains of born nitride wherein said glass film has a dielectric constant substantially equal to the dielectric constant of quartz or of said boron nitride.
Claim 3
Dependent Claim
21 words
A substrate according to claim 1, wherein said glass film has a thickness within the range of 10 to 15 microns.
Claim 4
Dependent Claim
22 words
A substrate according to claim 1, wherein said glass film has a dielectric constant substantially equal to the dielectric constant of quartz.
Claim 5
Dependent Claim
24 words
A substrate according to claim 1, wherein said glass film has a dielectric constant substantially equal to the dielectric constant of said boron nitride.
Claim 6
Dependent Claim
27 words
A substrate according to claim 1, wherein said glass film has a coefficient of linear thermal expansion substantially equal to the one of said boron nitride plate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-03 | 1987-10-03 | 1988-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-03 | 1991-10-03 | 1992-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-03 | 1995-10-03 | 1996-04-03 | $7700.00 | Window Closed / Lapsed |