Patent US4772509A successfully refreshed from Google Patents.
US4772509A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Printed circuit board base material
Assignee: GEC-MARONI Ltd
•
Filing: 1987-04-13
•
Granted: 1988-09-20
•
Expires: 2007-04-13
Abstract
Abstract A printed circuit board base prepreg material is provided of a porous, expanded polytetrafluoroethylene (PTFE) membrane or fabric impregnated with a polyimide resin varnish. Upon curing, a printed circuit board base material of porous, expanded PTFE impregnated with polyimide resin is provided. The base material of the invention may be laminated to a glass fabric to improve strength and dimensional stability.
Inventors
- 👤 Ichiro Komada
- 👤 Minoru Hatakeyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:39
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/12; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/16; B32B27/32; B32B27/322; B32B5/00; B32B5/22; B32B5/24; B32B5/28; C; C08; C08J; C08J5/00; C08J5/04; C08J5/24; C08J5/246; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; B29K; B29K2079/00; B29K2227/00; B29K2227/12; B29K2227/18; B29L; B29L2031/00; B29L2031/34; B29L2031/3425; B32B2260/00; B32B2260/04; B32B2260/046; B32B2262/00; B32B2262/10; B32B2262/101; B32B2305/00; B32B2305/07; B32B2305/076; B32B2307/00; B32B2307/20; B32B2327/00; B32B2327/12; B32B2327/18; B32B2457/00; B32B2457/08; C08J2379/00; C08J2379/04; C08J2379/08; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154; Y10T428/31544; Y10T428/31721; Y10T442/00; Y10T442/30; Y10T442/3854; Y10T442/3878
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
20 words
A printed circuit board base prepreg material comprising a membrane of a porous, expanded PTFE impregnated with a polyimide varnish.
Claim 2
Dependent Claim
20 words
A printed circuit board base prepreg material comprising a membrane of a porous, expanded PTFE impregnated with a polyimide varnish.
Claim 3
Dependent Claim
10 words
The material of claim 1 laminated to a glass fabric.
Claim 4
Dependent Claim
10 words
The material of claim 1 wherein said polyimide is cured.
Claim 5
Dependent Claim
10 words
The material of claim 3 laminated to a glass fabric.
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) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |