US4303715A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Printed wiring board
Assignee: AT&T Inc
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Filing: 1979-12-03
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Granted: 1981-12-01
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Expires: 1999-12-03
Abstract
Abstract A method of fabricating a printed circuit board is disclosed. The method comprises forming a metal substrate having a through-hole pattern. The metal substrate is coated with a dielectric powder having a suitable flow length value to form a dielectric coat on the substrate having a sufficient through-hole edge coverage. The dielectric coated substrate is then treated with a second powder to form a satisfactory topcoat thereon. Electrical circuitry is then formed on the topcoat in conjunction with the through hole pattern.
Inventors
- 👤 Joseph J. Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:33
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/44; H05K3/445; H05K1/00; H05K1/02; H05K1/03; H05K1/05; H05K1/056; H05K2201/00; H05K2201/09; H05K2201/09818; H05K2201/09827; H05K2203/00; H05K2203/10; H05K2203/105; H05K2203/13; H05K2203/1333; H05K2203/1355; H05K2203/15; H05K2203/1545; H05K3/0097; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49155; Y10T29/49165; Y10T29/49204; Y10T29/49224; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24322; Y10T428/24802; Y10T428/24893; Y10T428/24901; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/266
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
85 words
A printed circuit board comprising: (a) a metal substrate having a thickness of from about 1 to about 7 mils and a through hole; and (b) a dielectric coat on said substrate fused from particles of a thermosetting material having a flow length value defined by the area extending between lines A and B in the graph of FIG. 2, said dielectric coat having a through hole edge coverage of at least about 40 percent in thickness of the principle thickness of the dielecric coat.
Claim 2
Dependent Claim
85 words
A printed circuit board comprising: (a) a metal substrate having a thickness of from about 1 to about 7 mils and a through hole; and (b) a dielectric coat on said substrate fused from particles of a thermosetting material having a flow length value defined by the area extending between lines A and B in the graph of FIG. 2, said dielectric coat having a through hole edge coverage of at least about 40 percent in thickness of the principle thickness of the dielecric coat.
Claim 3
Dependent Claim
19 words
The printed circuit board as defined in claim 1 which further comprises a conductive pattern on said dielectric coat.
Claim 4
Dependent Claim
113 words
A printed circuit board comprising: (a) a metal substrate having a thickness of from about 1 to about 7 mils and a through hole; (b) a dielectric coat on said substrate fused from particles of a thermosetting material having a flow length value defined by the area extending between lines A and B in the graph of FIG. 2, said dielectric coat having a through hole edge coverage of at least about 40 percent in thickness of the principle thickness of the dielectric coat; and (c) a dielectric top coat on said dielectric coat wherein said topcoat is applied from a powder having a flow length value above curve A of FIG. 2.
Claim 5
Dependent Claim
113 words
A printed circuit board comprising: (a) a metal substrate having a thickness of from about 1 to about 7 mils and a through hole; (b) a dielectric coat on said substrate fused from particles of a thermosetting material having a flow length value defined by the area extending between lines A and B in the graph of FIG. 2, said dielectric coat having a through hole edge coverage of at least about 40 percent in thickness of the principle thickness of the dielectric coat; and (c) a dielectric top coat on said dielectric coat wherein said topcoat is applied from a powder having a flow length value above curve A of FIG. 2.
Claim 6
Dependent Claim
19 words
The printed circuit board as defined in claim 3 which further comprises a conductive circuit pattern on said topcoat.
Claim 7
Dependent Claim
19 words
The printed circuit board as defined in claim 3 wherein said topcoat flow length value is from 1.2-1.5 cm.
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) | 1984-11-30 | 1985-06-01 | 1985-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-30 | 1989-06-01 | 1989-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-30 | 1993-06-01 | 1993-12-01 | $7700.00 | Window Closed / Lapsed |