US3297555A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Etching of tantalum and columbium foils
Assignee: Cabot Berylco Inc
•
Filing: 1964-07-24
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Granted: 1967-01-10
•
Expires: 1984-07-24
Abstract
No abstract record available.
Inventors
- 👤 Carlos F Rerat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:50
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/004; H01G9/04; H01G9/048; H01G9/055; C; C25; C25F; C25F3/00; C25F3/02; C25F3/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
IN THE METHOD OF ETCHING TANTALUM AND COLUMBIUM FOIL WHEREIN THE FOIL IS IMMERSED IN A PREDOMINANTLY ALCOHOLIC ELECTROLYTIC ETCHING MEDIUM INCLUDING AT LEAST ONE INORGANIC HALIDE AND A PULSATING DUTY-CYCLE CURRENT HAVING AN "OFF" PERIOD BETWEEN EACH PULSE WHEREIN SUBSTANTIALLY NO CURRENT FLOWS IS PASSED TO THE SURFACE OF THE FOIL TO EFFECT THE DESIRED ETCHING THEREOF, THE IMPROVEMENT WHICH COMPRISES ADJUSTING THE AVERAG CURRENT OF THE DUTY CYCLE TO EFFECT THE DESIRED AMOUNT OF ETCHING, AND ADJUSTING THE DUTY RATIO AND FREQUENCY OF THE PULSATING CURRENT TO A VALUE SUCH THAT THE "OFF" PORTION OF THE TOTAL CYCLE PERIOD IS AT LEAST EQUAL TO THE TIME REQUIRED FOR THE PRODUCT OF THE ETCHING CURRENT TO BE DISSOLVED BY THE ETCHING MEDIUM.
Claim 2
Dependent Claim
123 words
IN THE METHOD OF ETCHING TANTALUM AND COLUMBIUM FOIL WHEREIN THE FOIL IS IMMERSED IN A PREDOMINANTLY ALCOHOLIC ELECTROLYTIC ETCHING MEDIUM INCLUDING AT LEAST ONE INORGANIC HALIDE AND A PULSATING DUTY-CYCLE CURRENT HAVING AN "OFF" PERIOD BETWEEN EACH PULSE WHEREIN SUBSTANTIALLY NO CURRENT FLOWS IS PASSED TO THE SURFACE OF THE FOIL TO EFFECT THE DESIRED ETCHING THEREOF, THE IMPROVEMENT WHICH COMPRISES ADJUSTING THE AVERAG CURRENT OF THE DUTY CYCLE TO EFFECT THE DESIRED AMOUNT OF ETCHING, AND ADJUSTING THE DUTY RATIO AND FREQUENCY OF THE PULSATING CURRENT TO A VALUE SUCH THAT THE "OFF" PORTION OF THE TOTAL CYCLE PERIOD IS AT LEAST EQUAL TO THE TIME REQUIRED FOR THE PRODUCT OF THE ETCHING CURRENT TO BE DISSOLVED BY THE ETCHING MEDIUM.
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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) | 1970-01-09 | 1970-07-11 | 1971-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-01-09 | 1974-07-11 | 1975-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-01-09 | 1978-07-11 | 1979-01-10 | $7700.00 | Window Closed / Lapsed |