US4025404A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ohmic contacts to thin film circuits
Assignee: Lignes Telegraphiques et Telephoniques LTT SA
•
Filing: 1975-11-04
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Granted: 1977-05-24
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Expires: 1995-11-04
Abstract
Abstract A process for establishing gold contact studs on thin film circuits consists in localized sublayer deposition of a platinum-gold alloy followed by subsequent electrolytic gold thickening of the studs. The studs so produced are particularly fit for thermocompression interconnection.
Inventors
- 👤 Jean Joly
- 👤 Jean Bernard Ranger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:45
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/05; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49101
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
74 words
Process for establishing contact studs on thin film resistor circuits coated on an insulating substrate, which comprises: cleaning said substrate. depositing Ta 2 N films thereon to constitute the circuit; cathode sputtering a gold-platinum alloy layer on the surface of said films; photoetching said gold-platinum layer through a mask protecting said stud locations; photoetching said thin film circuit through a photo mask and removing said photo mask and electrolytically thickening said studs with gold.
Claim 2
Dependent Claim
74 words
Process for establishing contact studs on thin film resistor circuits coated on an insulating substrate, which comprises: cleaning said substrate. depositing Ta 2 N films thereon to constitute the circuit; cathode sputtering a gold-platinum alloy layer on the surface of said films; photoetching said gold-platinum layer through a mask protecting said stud locations; photoetching said thin film circuit through a photo mask and removing said photo mask and electrolytically thickening said studs with gold.
Claim 3
Dependent Claim
17 words
Process according to claim 1 in which said gold-platinum alloy contains between 5 and 10% of platinum.
Claim 4
Dependent Claim
22 words
Process according to claim 1 in which the thickness of the layer of said gold-platinum alloy is between 0.1 and 0.2 micrometer.
Claim 5
Dependent Claim
16 words
Process according to claim 1 in which the circuit film deposition is achieved by cathode sputtering.
Claim 6
Dependent Claim
27 words
Process according to claim 1 in which the gold-platinum layer is obtained by cathode sputtering of a perforated gold sheet placed on top of a platinum foil.
Claim 7
Dependent Claim
13 words
A thin film resistor circuit including interconnecting studs made according to claim 1.
References Cited (Backward Citations)
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Cited
US3616406A
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US3793175A
Cited
US3864180A
Cited
US3907620A
Cited
US3921200A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-23 | 1980-11-22 | 1981-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-23 | 1984-11-22 | 1985-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-23 | 1988-11-22 | 1989-05-24 | $7700.00 | Window Closed / Lapsed |