US3841931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mild acid etch for tungsten
Assignee: AT&T Inc
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Filing: 1973-07-23
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Granted: 1974-10-15
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Expires: 1993-07-23
Abstract
Abstract 1. A METHOD OF ETCHING TUNGSTEN COMPRISING CONTACTING A TUNGSTEN SURFACE WITH AN AQUEOUS SOLLUTION OF AN ORGANIC ACID BUFFER AT A PH BELOW 7.0 WHILE EXPOSING SAID SURFACE TO AN AGENCY PROVIDING AN OXIDATION POTENTIAL BETWEEN 0.1 AND 0.6 VOLTS WHEN MEASURED WITH RESPECT TO THE SATURATED CALOMEL ELECTRODE.
Inventors
- 👤 D Macarthur
- 👤 P Skurkiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:14
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/26; C25; C25F; C25F3/00; C25F3/02; C25F3/08; H; H10; H10P; H10P50/00; H10P50/60; H10P50/66; H10P50/663; H10P50/667
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
49 words
A METHOD OF ETCHING TUNGSTEN COMPRISING CONTACTING A TUNGSTEN SURFACE WITH AN AQUEOUS SOLLUTION OF AN ORGANIC ACID BUFFER AT A PH BELOW 7.0 WHILE EXPOSING SAID SURFACE TO AN AGENCY PROVIDING AN OXIDATION POTENTIAL BETWEEN 0.1 AND 0.6 VOLTS WHEN MEASURED WITH RESPECT TO THE SATURATED CALOMEL ELECTRODE.
Claim 2
Independent Claim
49 words
A METHOD OF ETCHING TUNGSTEN COMPRISING CONTACTING A TUNGSTEN SURFACE WITH AN AQUEOUS SOLLUTION OF AN ORGANIC ACID BUFFER AT A PH BELOW 7.0 WHILE EXPOSING SAID SURFACE TO AN AGENCY PROVIDING AN OXIDATION POTENTIAL BETWEEN 0.1 AND 0.6 VOLTS WHEN MEASURED WITH RESPECT TO THE SATURATED CALOMEL ELECTRODE.
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) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |