US3663384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bath for electroplating tin-bismuth alloy
Assignee: International Business Machines Corp
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Filing: 1970-10-08
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Granted: 1972-05-16
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Expires: 1990-10-08
Abstract
Abstract Bath for electroplating tin-bismuth alloy upon a metal object such as a frame of a computer, including fluoboric acid in order to maintain the pH acid, tin fluoborate and a bismuth oxidebismuth sulphate mixture of low quantity. The utilized method is of the soluble anode type and the cathode is formed of the object to be coated.
Inventors
- 👤 Jean P Lescure
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:15
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/56; C25D3/60
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
9 words
An aqueous electroplating bath characterized in that it includes:
Claim 2
Dependent Claim
44 words
An aqueous acid fluoborate tin-bismuth alloy electroplating bath containing stannous ions, free fluoboric acid and an acid soluble mixture of bismuth sulphate and bismuth oxide in which the relative proportion of bismuth sulphate to bismuth oxide is in the range between 15/85 and 1.
Claim 3
Dependent Claim
28 words
A tin plating bath according to claim 3 wherein said bismuth mixture comprises bismuth sulphate and bismuth oxide in relative weight proportions of approximately 30 to 70 percent.
Claim 4
Dependent Claim
26 words
A tin plating bath according to claim 4 including approximately 1 gram per liter of formol as additive to inhibit anodic oxidation of the stannous ions.
Claim 5
Dependent Claim
32 words
A tin plating bath according to claim 4 wherein the concentration of said bismuth mixture in proportion to the total volume of the bath is between 0.1 and 0.5 grams per liter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |