US3796602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for stripping polymer masks from circuit boards
Assignee: EIDP Inc
•
Filing: 1972-02-07
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Granted: 1974-03-12
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Expires: 1992-02-07
Abstract
Abstract PHOTOHARDENED RESIST MASKS ARE STRIPPED FROM SUBSTRATE SURFACES, PARTICULARLY METAL SURFACES OF PRINTED CIRCUIT BOARDS, USING AN AQUEOUS STRIPPING LIQUID HEATED TO NEAR ITS PHASE TRANSITION TEMPERATURE, THE COMPOSITION CONTLAINING FROM 1 TO 50% OF A PARTIALLY MISCIBLE ORGANIC SOLVENT, THE CONCENTRATION TEMPERATURE ARE ADJUSTED SO THAT THE LIQUID IS AT OR NEAR ITS PHASE TRANSITION FROM A SINGLE SOLUTION TO TWO CONJUGAET SOLUTIONS. BY THIS PROCESS RESIST MASKS NORMALLY STRIPPED WITH MORE ECONOMICAL AND LESS HAZARSOUS RAPIDLY STRIPPED WITH MORE ECONMNICAL AND LESS HAZARDOUS AQUEOUS LIQUIDS.
Inventors
- 👤 G Briney
- 👤 J Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:37
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/42; G03F7/422; C; C23; C23G; C23G5/00; C23G5/02
Claims Analysis
Total Claims: 0
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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) | 1977-03-11 | 1977-09-10 | 1978-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-11 | 1981-09-10 | 1982-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-11 | 1985-09-10 | 1986-03-12 | $7700.00 | Window Closed / Lapsed |