US4153746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of sensitizing copper surfaces with sensitizing solution containing stannous ions, precious metal ions and EDTA
Assignee: International Business Machines Corp
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Filing: 1977-12-16
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Granted: 1979-05-08
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Expires: 1997-12-16
Abstract
Abstract A method of sensitizing surfaces which at least include areas of copper for subsequent electroless plating wherein the surface to be sensitized is processed with a sensitizing bath which includes precious metal ions, stannous ions in stoichiometric surplus, a haloid acid, and a complex forming compound for copper ions.
Inventors
- 👤 Hans D. Kilthau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:22
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/20; C23C18/28
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
100 words
In a method of sensitizing surfaces which include areas of copper for the subsequent electroless metallization, where the surface to be sensitized is processed with a sensitizing solution with a pH of less than 1 containing precious metal ions, stannous ions in stoichiometric surplus, and a haloid acid, the improvement comprising; admixing to the sensitizing bath a complex forming compound for copper ions selected from the group consisting of ethylene diamine tetra-acetic acid and alkali metal salts of ethylene diamine tetra-acetic acid to thereby maintain a low concentration of free copper ions and contacting said surfaces with said sensitizing bath.
Claim 2
Dependent Claim
100 words
In a method of sensitizing surfaces which include areas of copper for the subsequent electroless metallization, where the surface to be sensitized is processed with a sensitizing solution with a pH of less than 1 containing precious metal ions, stannous ions in stoichiometric surplus, and a haloid acid, the improvement comprising; admixing to the sensitizing bath a complex forming compound for copper ions selected from the group consisting of ethylene diamine tetra-acetic acid and alkali metal salts of ethylene diamine tetra-acetic acid to thereby maintain a low concentration of free copper ions and contacting said surfaces with said sensitizing bath.
Claim 3
Dependent Claim
22 words
The method as claimed in claim 1, wherein the complex forming compound is used in a concentration of at least 1 g/l.
Claim 4
Dependent Claim
30 words
The method of claim 1 wherein said precious metal ions in said sensitizing bath are selected from the group consisting of palladium, platinum, gold, rhodium, osmium, iridium, and mixtures thereof.
Claim 5
Dependent Claim
29 words
The method as claimed in claim 1, wherein a sensitizing bath containing palladium chloride, stannous chloride in stoichiometric surplus, hydrochloric acid, and ethylene diamine tetra-acetic acid-sodium salt is used.
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) | 1982-05-07 | 1982-11-06 | 1983-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-07 | 1986-11-06 | 1987-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-07 | 1990-11-06 | 1991-05-08 | $7700.00 | Window Closed / Lapsed |