US3855141A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of processing a spent copper etching solution for reuse in an electroless copper recovery baths
Assignee: Loewe Opta GmbH
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Filing: 1973-08-22
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Granted: 1974-12-17
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Expires: 1993-08-22
Abstract
Abstract Process improvements are described for obtaining long term stability during the electroless recovery of etched copper from a spent acidic copper chloride etching solution having a large concentration of a CuCl component. The spent solution is enriched by the addition of copper ions which are oxidized in the presence of an alkaline complex component to increase the concentration of CuCl2 in the solution and to thereby decrease the concentration of CuCl.
Inventors
- 👤 C Ruff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:00
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/38
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
133 words
FOR USE IN THE RECOVERY OF COPPER THAT IS ETCHED WITH TTHE USE OF AN ACIDIC SOLUTION CONTAINING CUC12 WHEREIN A PORTION OF THE CUCI2 IS CONVERTED INTO CUCI DURING SUCH ETCHING OPERATION AS THE SOLUTION BECOMES SPENT, A METHOD OF PREPARING THE SPENT ETCHING SOLUTION FOR REUSE IN THE SPARATION OF THE ETCHED COPPER BY ELECTROLESS MEANS WHICH COMPRISES THE STEPS OF ADDING COPPER IONS TO THE SPENT SOLUTION TO A PREDETERMINED SEPARATION; AND THEREAFTER ADDING TO THE ENRICHED SOLUTION COPPER CONCENTRATION SUITABLE FOR ELECTROLESS COPPER AN OXIDIZING AGENT AND AN ALKALINE COMPLEX COMPONENT ON AMOUNTS RESPCTIVELY EFFECTIVE TO (1) OXIDIZE THE ADDED COPPER TO INCREASE THE CONCENTRATION OF CU-CI2 IN THE SOLUTION AND CORRESPO NDING DECREASE THE CONCENTRATION OF CUCI, AND (20 TO CONVERT THE ETCHING SOLUTION INTO AN ALKALINE BATH.
Claim 2
Dependent Claim
133 words
FOR USE IN THE RECOVERY OF COPPER THAT IS ETCHED WITH TTHE USE OF AN ACIDIC SOLUTION CONTAINING CUC12 WHEREIN A PORTION OF THE CUCI2 IS CONVERTED INTO CUCI DURING SUCH ETCHING OPERATION AS THE SOLUTION BECOMES SPENT, A METHOD OF PREPARING THE SPENT ETCHING SOLUTION FOR REUSE IN THE SPARATION OF THE ETCHED COPPER BY ELECTROLESS MEANS WHICH COMPRISES THE STEPS OF ADDING COPPER IONS TO THE SPENT SOLUTION TO A PREDETERMINED SEPARATION; AND THEREAFTER ADDING TO THE ENRICHED SOLUTION COPPER CONCENTRATION SUITABLE FOR ELECTROLESS COPPER AN OXIDIZING AGENT AND AN ALKALINE COMPLEX COMPONENT ON AMOUNTS RESPCTIVELY EFFECTIVE TO (1) OXIDIZE THE ADDED COPPER TO INCREASE THE CONCENTRATION OF CU-CI2 IN THE SOLUTION AND CORRESPO NDING DECREASE THE CONCENTRATION OF CUCI, AND (20 TO CONVERT THE ETCHING SOLUTION INTO AN ALKALINE BATH.
Claim 3
Dependent Claim
23 words
A method as defined in claim 1, in which the alkaline complex component has a pH in the range between 11.5 and 12.5.
Claim 4
Dependent Claim
26 words
A method as defined in claim 1, in which the oxidizing agent is selected from the group consisting of hydrogen peroxide, free oxygen, and a chlorate.
Claim 5
Dependent Claim
25 words
A method as defined in claim 1, in which the alkaline complex component is selected from the group consisting of EDTA, nitriloessic acid and thriethanolamine.
References Cited (Backward Citations)
US3438901A
Cited
US3600244A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |