Patent US3607474A successfully refreshed from Google Patents.
US3607474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making an optical mask for reproducing circuit boards
Assignee: United States Department of the Army
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Filing: 1968-01-26
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Granted: 1971-09-21
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Expires: 1988-01-26
Abstract
Abstract A method of making an etched stripline circuit board comprising a copper-clad substrate covered with an etch-resist Mylar tape. A precision coordinatograph is employed for cutting the circuit through the Mylar tape on a 1:1 scale; unneeded portions of the tape are stripped away, and the remaining portions of the tape are utilized as a resist during an etching process.
Inventors
- 👤 Samuel H Hensdale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:58
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/0002; H05K2203/00; H05K2203/05; H05K2203/0548; H05K2203/056; H05K3/02; H05K3/06; H05K3/061
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
23 words
The process as set forth in claim 1 wherein a polyethylene terephthalate sheet of approximately 0.005 inches thick is utilized as said substrate.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |