US4009299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tin strip formulation for metal to glass seal diodes
Assignee: Motorola Solutions Inc
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Filing: 1975-10-22
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Granted: 1977-02-22
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Expires: 1995-10-22
Abstract
Abstract Immersion of semiconductor devices, particularly diodes, having a defective tin plating thereon in a solution of 5 - 20 percent by weight trichloroacetic acid, 0.1 to 5 percent by weight of a compound selected from the group consisting of cationic, anionic, and nonionic surfactants and the balance water effectively removes the tin therefrom. The process is effective at room temperature but preferably is performed at approximately 100 DEG C.
Inventors
- 👤 Dervin L. Flowers
- 👤 Richard L. Greeson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:36
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/15; C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/30
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
59 words
A process for the reclamation of semiconductor devices comprising: providing semiconductor devices having a defective tin plating thereon; and immersing said devices, for about 5-10 minutes, in a solution of 5-20 percent by weight trichloroacetic acid, 0.1 to 5 percent by weight of a compound selected from the group consisting of cationic, anionic, nonionic surfactants, and the balance water.
Claim 2
Dependent Claim
59 words
A process for the reclamation of semiconductor devices comprising: providing semiconductor devices having a defective tin plating thereon; and immersing said devices, for about 5-10 minutes, in a solution of 5-20 percent by weight trichloroacetic acid, 0.1 to 5 percent by weight of a compound selected from the group consisting of cationic, anionic, nonionic surfactants, and the balance water.
Claim 3
Dependent Claim
19 words
A process as recited in claim 1 wherein said solution is maintained at a temperature of approximately 100° C.
Claim 4
Dependent Claim
23 words
A process as recited in claim 2 and further including the step of replating said devices in a sulfuric acid (stannous sulfate solution).
References Cited (Backward Citations)
US2721119A
Cited
US3072579A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-22 | 1980-08-23 | 1981-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-22 | 1984-08-23 | 1985-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-22 | 1988-08-23 | 1989-02-22 | $7700.00 | Window Closed / Lapsed |