Patent US3764379A successfully refreshed from Google Patents.
US3764379A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diminishing mask wearout during terminal formation
Assignee: Cogar Corp
•
Filing: 1971-04-26
•
Granted: 1973-10-09
•
Expires: 1991-04-26
Abstract
Abstract TERMINALS FOR A SEMICONDUCTIVE DEVICE ARE FORMED BY SUCCESSIVELY DEPOSITING CHROMIUM, COPPER AND GOLD THROUGH A MASK INTO THE TERMINAL HOLES OF THE DEVICE. WEAROUT OF THE MOLYBDENUM MASKS EMPLOYED DURING FORMATION OF THE TERMINALS IS GREATLY DIMINISHED BY COATING THE MASK WITH A FILM OF COPPER, TYPICALLY 700-3000 A. UNITS THICK PRIOR TO THE MULTIMETAL DEPOSITION. THE CLEANING SOLUTION, TYPICALLY SODIUM CYANIDE, REQUIRED TO REMOVE THE COPPER-CHROMIUM-COPPER-GOLD LAYER FROM THE COPPER COATED MASK IS EASIER ON THE MASK AND C AUSES LESS WEAROUT THAN THE SOLUTION REQUIRED TO REMOVE THE CHROMIUMCOPPER-GOLD DEPOSIT FROM UNCOATED MOLYBEDENUM MASKS.
Inventors
- 👤 J Tuttle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:02
CPC Classifications
H; H10; H10P; H10P95/00; H10W; H10W20/00; H10W20/40; H10W72/00; H10W72/20; H10W72/251; H10W72/90; H10W72/921; H10W72/923; H10W72/951; H10W72/952; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/945
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |