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US3661635A
Expired / Lapsed
US
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Dual-etched refractory metallizing
Assignee: American Lava Corp
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Filing: 1970-02-20
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Granted: 1972-05-09
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Expires: 1990-02-20
Abstract
Abstract A process for metallizing on ceramic substrates with fine detail patterns of refractory metal which includes a prefiring to effect oxidation of a portion of the metallizing coating, application of a photopolymerizable coating thereover followed by exposure in pattern form using a mask, removal of unpolymerized coating by conventional means, acid etching to remove the oxides formed during pre-firing in exposed portions of the metallizing coating and mechanical removal of unoxidized and unsintered metal remaining in etched portions. This is followed by a final firing which destroys the photoresist and sinters the metal remaining on the substrate.
Inventors
- 👤 Henry F Harrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:22
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/51; C04B41/5133; C04B41/5138; C04B41/80; C04B41/81; C04B41/85; C04B41/88; H; H05; H05K; H05K3/00; H05K3/02; H10; H10D; H10D84/00; H10D84/01; H05K1/00; H05K1/02; H05K1/09; H05K1/092; H05K2203/00; H05K2203/02; H05K2203/025; H05K3/06; H05K3/061; H05K3/064; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/24917; Y10T428/24926
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
168 words
A process for the production of a sintered refractory metal pattern on a refractory substrate comprising the steps of: A. applying a uniform layer of metallizing paste comprising tungsten or molybdenum manganese in suitable vehicle to a fired ceramic substrate and prefiring said layer of metallizing paste to a temperature of about 500* C. in an oxidizing atmosphere for about 10 to 15 minutes, B. applying a thin coating less than 1 mm. thick of photopolymerizable composition to said prefired refractory metal layer, C. patternwise exposing said coating of photopolymerizable composition to actinic light to generate a polymerized masking pattern, D. removing unpolymerized parts of said photopolymerizable layer to expose unmasked partially oxidized metallized layer, E. solubilizing oxides in the unmasked metallized layer, F. removing the unmasked metallized layer after solubilization of oxides by abrasion means and thorough cleaning and G. firing the substrate with patterned layers in reducing atmosphere at a temperature sufficiently high to destroy and volatilize residual photopolymer mask and sinter the refractory metallic layer.
Claim 2
Dependent Claim
34 words
A process according to claim 2 wherein oxides in the unmasked metallized layer are solubilized by treating with aqueous acid for from about 1/2 to about 20 minutes at about 10* to 35* C.
Claim 3
Dependent Claim
21 words
A process according to claim 2 where abrasion means are an application of mechanical force by brushing or spraying under pressure.
Claim 4
Dependent Claim
57 words
The combination of fully fired ceramic substrate, on at least a portion of said substrate a layer of tungsten or molybdenum manganese partially oxidized and freed from organic binder by heating at about 500* C. in an oxidizing atmosphere for about 10 to 15 minutes and a layer at least covering said refractory metal of photopolymerizable composition.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |