US4916017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet material
Assignee: W.L. Gore and Associates Inc
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Filing: 1988-08-31
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Granted: 1990-04-10
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Expires: 2008-08-31
Abstract
Abstract A composite sheet material comprises a porous, expanded polytetrafluoroethylene base sheet 1 impregnated with a first resin 2 that has a lower heat-shrinkability than the base sheet, the impregnated base sheet having a covering layer 3 which has a thickness of at least three micrometers and which comprises a second resin whose hardening rate is lower that that of the impregnating resin. The present invention is useful in printed circuit boards wherein a prepreg as above described is laminated with a metal sheet, a resin sheet, or another printed circuit board.
Inventors
- 👤 Haruo Nomi
- 👤 Minoru Hatakeyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:03
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/02; B29C70/026; B32; B32B; B32B5/00; B32B5/18; B29C70/04; B29C70/26; B32B15/00; B32B15/04; B32B15/08; B32B15/20; B32B27/00; B32B27/06; B32B27/065; C; C08; C08J; C08J9/00; C08J9/36; C08J9/40; C08J9/42; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; B29K; B29K2027/00; B29K2027/12; B29K2027/18; B29K2105/00; B29K2105/04; B29L; B29L2031/00; B29L2031/34; B29L2031/3425; B32B2260/00; B32B2260/04; B32B2260/046; B32B2266/00; B32B2266/02; B32B2266/0214; B32B2266/025; B32B2307/00; B32B2307/70; B32B2307/732; B32B2307/734; B32B2311/00; B32B2311/12; B32B2457/00; B32B2457/08; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18; C08J2421/00; C08J2427/00; C08J2461/00; C08J2463/00; C08J2479/00; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31515; Y10T428/3154; Y10T428/31544; Y10T428/31721
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
60 words
A composite sheet material comprising a porous, expanded polytetrafluoroethylene base sheet impregnated with a first resin that has a lower heat-shrinkability than said base sheet, said impregnated base sheet having a covering layer which has a thickness of at least three (3) micrometers and which comprises a second resin whose hardening rate is lower than that of said impregnating resin.
Claim 2
Dependent Claim
60 words
A composite sheet material comprising a porous, expanded polytetrafluoroethylene base sheet impregnated with a first resin that has a lower heat-shrinkability than said base sheet, said impregnated base sheet having a covering layer which has a thickness of at least three (3) micrometers and which comprises a second resin whose hardening rate is lower than that of said impregnating resin.
Claim 3
Dependent Claim
16 words
The composite sheet material of claim 1 wherein said first resin is in a semi-hardened site.
Claim 4
Dependent Claim
16 words
The composite sheet material of claim 1 wherein said first resin is in a fully-hardened state.
Claim 5
Dependent Claim
16 words
The composite sheet material of claim 1 wherein said second resin is in a semi-hardened state.
Claim 6
Dependent Claim
16 words
The composite sheet material of claim 1 wherein said second resin is in a fully-hardened state.
Claim 7
Dependent Claim
14 words
The composite sheet material of claim 1 wherein said first resin is a polyimide.
Claim 8
Dependent Claim
14 words
The composite sheet material of claim 1 wherein said first resin is an epoxy.
Claim 9
Dependent Claim
13 words
The composite sheet material of claim 1 wherein said first resin is polybutadiene.
Claim 10
Dependent Claim
14 words
The composite sheet material of claim 1 wherein said second resin is an epoxy.
Claim 11
Dependent Claim
14 words
The composite sheet material of claim 1 wherein said second resin is a phenolic.
Claim 12
Dependent Claim
18 words
The composite sheet material of claim 1 wherein said second resin is a copolymer of tetrafluoroethylene and hexafluoropropylene.
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) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |