US3345217A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of cleaning and phosphatizing copper circuits
Assignee: Fremont Industries Inc
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Filing: 1964-06-01
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Granted: 1967-10-03
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Expires: 1984-06-01
Abstract
No abstract record available.
Inventors
- 👤 Herbert R Wollgien
- 👤 Edward H Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:42
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/46; C23C22/47; H; H05; H05K; H05K3/00; H05K3/22; H05K2203/00; H05K2203/02; H05K2203/025; H05K2203/03; H05K2203/0315; H05K2203/0392; H05K2203/11; H05K2203/1157; H05K3/28; H05K3/282; H05K3/30; H05K3/32; H05K3/34; H05K3/3489
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
129 words
THE METHOD OF CLEANING AND REMOVING SURFACE FILMS FROM THE EXPOSED SURFACE OF COPPER CONDUCTORS DISPOSED ON THE SURFACE OF AN INSULATING BASE OF A PRINTED WIRING BOARD COMPRISING THE STEPS OF APPLYING AND WIPING A FREE FLOWING POWDER OR PASTE MIXTURE OF OXALIC ACID, AN ACID PHOSPHATE, TOGETHER WITH A FINELY DIVIDED GRIT ONTO SAID EXPOSED CONDUCTOR SURFACE, SAID ACID PHOSPHATE IN SAID MIXTURE CONSISTING ESSENTIALLY OF AN ALKALINE EARTH PHOSPHATE AND PHOSPHORIC ACID, THE RATIO OF THE PHOSPHATE ION TO THE OXALATE ION IN THE MIXTURE BEING IN THE RANGE OF FROM BETWEEN ABOUT 2:1 AND 1:2, SAID FINELY DIVIDED GRIT IN SAID MIXTURE CONSISTING ESSENTIALLY OF SILICA FLOUR HAVING A PARTICLE SIZE GENERALLY BELOW ABOUT 140 MESH AND FORMING SUBSTANTIALLY 85 PERCENT OF THE COMPOSITION MIX.
Claim 2
Independent Claim
129 words
THE METHOD OF CLEANING AND REMOVING SURFACE FILMS FROM THE EXPOSED SURFACE OF COPPER CONDUCTORS DISPOSED ON THE SURFACE OF AN INSULATING BASE OF A PRINTED WIRING BOARD COMPRISING THE STEPS OF APPLYING AND WIPING A FREE FLOWING POWDER OR PASTE MIXTURE OF OXALIC ACID, AN ACID PHOSPHATE, TOGETHER WITH A FINELY DIVIDED GRIT ONTO SAID EXPOSED CONDUCTOR SURFACE, SAID ACID PHOSPHATE IN SAID MIXTURE CONSISTING ESSENTIALLY OF AN ALKALINE EARTH PHOSPHATE AND PHOSPHORIC ACID, THE RATIO OF THE PHOSPHATE ION TO THE OXALATE ION IN THE MIXTURE BEING IN THE RANGE OF FROM BETWEEN ABOUT 2:1 AND 1:2, SAID FINELY DIVIDED GRIT IN SAID MIXTURE CONSISTING ESSENTIALLY OF SILICA FLOUR HAVING A PARTICLE SIZE GENERALLY BELOW ABOUT 140 MESH AND FORMING SUBSTANTIALLY 85 PERCENT OF THE COMPOSITION MIX.
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) | 1970-10-02 | 1971-04-03 | 1971-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-10-02 | 1975-04-03 | 1975-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-10-02 | 1979-04-03 | 1979-10-03 | $7700.00 | Window Closed / Lapsed |