US3833433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing tarnish resistant copper and copper alloys and products thereof
Assignee: Olin Corp
•
Filing: 1973-06-14
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Granted: 1974-09-03
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Expires: 1993-06-14
Abstract
Abstract The disclosure teaches providing copper or a copper alloy, applying a phosphoric acid - dichromate solution to said material, immersing said material in an aqueous solution containing an alkali metal phosphate in a concentration of at least 18 percent by weight, and rinsing said material.
Inventors
- 👤 E Caule
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:26
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H05K3/382; H05K3/385; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
19 words
A method according to claim 1 wherein the treatment time in Step D. is for at least 5 seconds.
Claim 2
Dependent Claim
28 words
A method according to claim 1 wherein said alkali metal phosphate in step D. is utilized in a concentration of at least 18 percent by weight to solubility.
Claim 3
Dependent Claim
25 words
A method according to claim 1 wherein said solution in step D. is maintained at a temperature of from 90* C to the boiling point.
Claim 4
Dependent Claim
30 words
A method according to claim 1 wherein said solution in step D. is maintained at a pH in the range of 2 to 4 by the addition of phosphoric acid.
Claim 5
Dependent Claim
40 words
A method according to claim 1 wherein said rinsing step E. is for at least 2 seconds in water maintained at a pH of at least 8.0 and at a temperature from about 90* C up to the boiling point.
Claim 6
Dependent Claim
68 words
A method according to claim 6 wherein said water is adjusted to a pH of at least 8.0 with a compound selected from the group consisting of the basic reaction salts of the alkali metals, the basic reaction salts of the alkaline earth metals, the hydroxides of the alkali metals, the hydroxides of the alkaline earth metals, ammonium salts with a basic reaction, ammonium hydroxide and mixtures thereof.
Claim 7
Dependent Claim
21 words
A method according to claim 6 wherein the pH is adjusted to the range of 8.0 to 11.0 with calcium hydroxide.
Claim 8
Dependent Claim
31 words
A method according to claim 6 wherein said material is first rinsed in water prior to said rinsing step for at least 2 seconds at a pH of at least 8.0.
Claim 9
Dependent Claim
14 words
A method according to claim 1 wherein said copper is copper sheet or foil.
Claim 10
Dependent Claim
24 words
A method according to claim 1 wherein in step B. when the concentration of phosphoric acid is increased, the minimum dichromate is proportionately increased.
Claim 11
Dependent Claim
19 words
A method according to claim 1 wherein the immersion time in step B. is from 7 to 30 seconds.
Claim 12
Dependent Claim
15 words
A method according to claim 1 wherein the phosphate in step D. is sodium hexametaphosphate.
Claim 13
Independent Claim
149 words
A method of producing a flexible laminate comprising: A. providing a material selected from the group consisting of copper and copper alloys; B. applying to said material a phosphoric acid solution of at least 8 percent concentration and containing from 3.5 grams per liter up to the solubility limit of a material selected from the group consisting of sodium dichromate and potassium dichromate and mixtures thereof, for at least 2 seconds; C. rinsing said material in water; D. immersing said material for at least 2 seconds in an aqueous solution containing an alkali metal phosphate in a concentration of at least 18 percent by weight, said solution being maintained at a temperature of at least 80* C and at a pH in the range of 2 to 4; E. finally rinsing said material in water; F. drying said material; and G. adhesively laminating a plastic film to said surface.
Claim 14
Independent Claim
214 words
A method of producing a flexible printed circuit comprising: A. providing a material selected from the group consisting of copper and copper alloys; B. applying to said material a phosphoric acid solution of at least 8 percent concentration and containing from 3.5 grams per liter up to the solubility limit of a material selected from the group consisting of sodium dichromate and Potassium dichromate and mixtures thereof, for at least 2 seconds; C. rinsing said material in water; D. immersing said material for at least 2 seconds in an aqueous solution containing an alkali metal phosphate in a concentration of at least 18 percent by weight, said solution being maintained at a temperature of at least 80* C and at a pH in the range of 2 to 4, E. finally rinsing said material in water; F. drying said material; G. adhesively laminating a plastic film to said surface; H. applying a photoresist to the opposing surface of said material; I. projecting a circuitry pattern upon said photoresist wherein said photoresist is transformed into an acid insoluble compound at said circuitry pattern; J. dissolving away the unwanted portion of said material from said circuitry pattern by an acid solution; K. rinsing said surface; and L. drying said surface, thereby forming a flexible printed circuit.
References Cited (Backward Citations)
US3677828A
Cited
US3716427A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |