Patent US3770464A successfully refreshed from Google Patents.
US3770464A
Expired / Lapsed
US
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Dry replenishment of electroless copper solutions
Assignee: Shipley Co Inc
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Filing: 1971-10-12
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Granted: 1973-11-06
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Expires: 1991-10-12
Abstract
Abstract This invention is for replenishment of an aqueous electroless copper plating solution and to apparatus useful therefore. The process comprises addition of replenishers in essentially dry form in a manner that avoids triggering of the bath. Typical replenishers that may be added in dry form include one or more of a source of cupric ions such as cupric sulphate, a reducing agent for cupric ions such as paraformaldehyde, a chelating agent for cupric ions, bath stabilizers, brighteners, surfactants and the like. These ingredients may be added singularly or admixed with each other. Essentially dry materials are used for replenishment rather than a solution as in the prior art to prevent volume growth of the plating solution.
Inventors
- 👤 O Dutkewych
- 👤 L Hofman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:08
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/1601; C23C18/1617; C25; C25D; C25D21/00; C25D21/16; C25D21/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
27 words
The method of claim 1 where the solution is maintained stable by replenishment with a stabilizer prior to or during replenishment with at least the cupric salt.
Claim 2
Dependent Claim
18 words
The method of claim 1 wherein the solution is maintained stable by bubbling air through the plating solution.
Claim 3
Dependent Claim
26 words
The method of claim 1 where the solution is maintained stable by use of an excess of a non-poisoning stabilizing agent in the original solution make-up.
Claim 4
Dependent Claim
27 words
The method of claim 1 where the localized areas of high concentration of replenisher constituents are avoided and rapid dissolution of constituents is accomplished with solution aggitation.
Claim 5
Dependent Claim
23 words
The method of claim 1 where the replenisher constituents are added directly to the plating solution beneath the level of the plating solution.
Claim 6
Dependent Claim
86 words
The method of claim 1 where said replenisher constituents are added and substantially dissolved beneath the level of the plating solution by circulating a minor portion of the plating solution external to the major portion of said solution, through a mass of said replenisher constituents to substantially dissolve the same whereby the replenisher constituents are maintained substantially out of contact with the surface of the plating solution, and recirculating said minor portion of solution enriched in replenisher constituents back to the major portion of said solution.
Claim 7
Dependent Claim
16 words
The method of claim 7 where said minor portion of solution is passed through replenisher constituents.
Claim 8
Dependent Claim
33 words
The method of claim 7 where said minor portion of solution has its speed increased as it passes through said replenisher constituents by imparting a swirling motion to said minor portion of solution.
Claim 9
Dependent Claim
21 words
The method of claim 7 where said replenisher constituents comprise at least 2 moles of paraformaldehyde per mole of cupric salt.
Claim 10
Dependent Claim
22 words
The method of claim 10 where said replenisher constituents also include a minor amount of a stabilizing agent for the plating solution.
Claim 11
Dependent Claim
17 words
The method of claim 10 where said replenisher constituents also include a minor amount of chelating agent.
Claim 12
Dependent Claim
15 words
The method of claim 7 where said replenisher constituents are in essentially dry powder form.
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) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |