Patent US3463733A successfully refreshed from Google Patents.
US3463733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for etching printed circuits
Assignee: FMC Corp
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Filing: 1965-08-18
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Granted: 1969-08-26
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Expires: 1985-08-18
Abstract
No abstract record available.
Inventors
- 👤 Karl Achenbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:44
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
64 words
IN A PROCESS FOR ETCHING PRINTED COPPER CIRCUITS, THE STEP OF EFFECTING SUCH ETCHING WITH A MINERAL ACID SOLUTION CONSISTING ESSENTIALLY OF WATER, 0.01 TO 0.7 KILOGRAM PER LITER OF SULFURIC ACID OR PHOSPHORIC ACID, 1.5 TO 10% H2O2 AND 1 TO 15% OF A STABILIZER FOR THE H2O2 SELECTED FROM THE GROUP CONSISTING OF UREA, SEMICARBAZIDE, BIURET, BARBITURIC ACID AND DIPROPYL BARBITURIC ACID.
Claim 2
Dependent Claim
64 words
IN A PROCESS FOR ETCHING PRINTED COPPER CIRCUITS, THE STEP OF EFFECTING SUCH ETCHING WITH A MINERAL ACID SOLUTION CONSISTING ESSENTIALLY OF WATER, 0.01 TO 0.7 KILOGRAM PER LITER OF SULFURIC ACID OR PHOSPHORIC ACID, 1.5 TO 10% H2O2 AND 1 TO 15% OF A STABILIZER FOR THE H2O2 SELECTED FROM THE GROUP CONSISTING OF UREA, SEMICARBAZIDE, BIURET, BARBITURIC ACID AND DIPROPYL BARBITURIC ACID.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-08-25 | 1973-02-24 | 1973-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-08-25 | 1977-02-24 | 1977-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-08-25 | 1981-02-24 | 1981-08-26 | $7700.00 | Window Closed / Lapsed |