US4434544A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer circuit and process for manufacturing the same
Assignee: NEC Corp
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Filing: 1982-09-30
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Granted: 1984-03-06
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Expires: 2002-09-30
Abstract
Abstract A multilayer circuit construction includes a conductive layer formed of an alloy of a noble metal and a small amount of a base metal disposed on a heat resistant insulating substrate. The portion of the substrate not covered with the conductive alloy is covered with an oxide of the base metal constituent of the alloy. The construction may be formed by depositing a base metal layer over the substrate, followed by depositing the noble metal over a part of the base metal layer. By oxidizing at high temperatures, the exposed base metal layer is converted to oxide, while the noble metal and the base metal thereunder diffuse into each other to form the alloy.
Inventors
- 👤 Akihiro Dohya
- 👤 Yasuhiko Hino
- 👤 Mitsuo Abe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:18
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/80; H10D86/85; H05; H05K; H05K3/00; H05K3/10; H05K3/108; H05K3/46; H05K3/4644; H05K3/4647; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K1/09; H05K2203/00; H05K2203/03; H05K2203/0315; H05K2203/07; H05K2203/0703; H05K2203/0733; H05K2203/11; H05K2203/1142; H05K3/22; H05K3/24; H05K3/243
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
146 words
A process for manufacturing a multilayer circuit comprising the steps of: depositing a layer consisting of a base metal on a heat-resistant insulating substrate; depositing a thin film layer of a first noble metal on said layer of base metal; depositing a conducting layer of second noble metal on a predetermined region of said thin film layer of said first noble metal; converting the remaining region, not covered by said conducting layer, of said base metal into an insulating metal oxide by oxidizing at a high temperature, said oxidizing step also producing an alloy of said first noble metal and said second noble metal; and removing the remaining region, not covered by said conducting layer, of said thin film layer of said first noble metal by etching with an etching solution ineffective for etching the alloy of said first noble metal and said second noble metal.
Claim 2
Dependent Claim
146 words
A process for manufacturing a multilayer circuit comprising the steps of: depositing a layer consisting of a base metal on a heat-resistant insulating substrate; depositing a thin film layer of a first noble metal on said layer of base metal; depositing a conducting layer of second noble metal on a predetermined region of said thin film layer of said first noble metal; converting the remaining region, not covered by said conducting layer, of said base metal into an insulating metal oxide by oxidizing at a high temperature, said oxidizing step also producing an alloy of said first noble metal and said second noble metal; and removing the remaining region, not covered by said conducting layer, of said thin film layer of said first noble metal by etching with an etching solution ineffective for etching the alloy of said first noble metal and said second noble metal.
Claim 3
Dependent Claim
117 words
A process for manufacturing a multilayer circuit comprising the steps of: depositing a layer consisting of a first base metal on a heat-resistant insulating substrate; depositing a thin film layer consisting of a second base metal on a predetermined region of said layer of said first base metal; removing a portion of said thin film layer by etching, to expose a portion of said first base metal; depositing a conducting layer of a noble metal on said exposed portion of said layer of said first base metal by plating; and converting the remaining region, not covered by said conducting layer, of said first and second base metals into, insulating metal oxides, by oxidizing at a high temperature.
Claim 4
Dependent Claim
117 words
A process for manufacturing a multilayer circuit comprising the steps of: depositing a layer consisting of a first base metal on a heat-resistant insulating substrate; depositing a thin film layer consisting of a second base metal on a predetermined region of said layer of said first base metal; removing a portion of said thin film layer by etching, to expose a portion of said first base metal; depositing a conducting layer of a noble metal on said exposed portion of said layer of said first base metal by plating; and converting the remaining region, not covered by said conducting layer, of said first and second base metals into, insulating metal oxides, by oxidizing at a high temperature.
Claim 5
Dependent Claim
123 words
A process for manufacturing a multilayer circuit comprising the steps of: depositing a layer of a base metal on a heat-resistant insulating substrate; depositing a conducting layer of a noble metal on a predetermined region of said base metal layer; depositing a connecting layer of the same noble metal as that of said conducting layer on a predetermined region of said conducting layer; converting the regions, not covered by said conducting layer, of said base metal into an insulating metal oxide by oxidizing at a high temperature; and depositing an insulating layer on both the uncovered regions of said conducting layer, and on said insulating base metal oxide to a level equal to the level of the top surface of said connecting layer.
Claim 6
Dependent Claim
123 words
A process for manufacturing a multilayer circuit comprising the steps of: depositing a layer of a base metal on a heat-resistant insulating substrate; depositing a conducting layer of a noble metal on a predetermined region of said base metal layer; depositing a connecting layer of the same noble metal as that of said conducting layer on a predetermined region of said conducting layer; converting the regions, not covered by said conducting layer, of said base metal into an insulating metal oxide by oxidizing at a high temperature; and depositing an insulating layer on both the uncovered regions of said conducting layer, and on said insulating base metal oxide to a level equal to the level of the top surface of said connecting layer.
Claim 7
Dependent Claim
26 words
A process for manufacturing a multilayer circuit claimed in claim 1, or claim 2, wherein said high temperature is set at 600 to 900 degrees centigrade.
Claim 8
Dependent Claim
23 words
A process for manufacturing a multilayer circuit claimed in claim 3, wherein said high temperature is set at 600 to 900 degrees centigrade.
Claim 9
Dependent Claim
73 words
A process for manufacturing a multilayer circuit as claims in claim 3, wherein the step of depositing and insulating layer comprises the steps of: (a) depositing a thick layer of insulating paste over the insulating base metal oxide layer, the conducting layer and the connecting layer; (b) baking said paste at a high temperature; and (c) grinding said baked layer of insulating paste until the top surface of said connecting layer is exposed.
Claim 10
Dependent Claim
39 words
A process for manufacturing a multilayer circuit as claimed in claim 1, further comprising the step, prior to depositing said conductive layer, of depositing a layer of photoresist material over said thin film layer except for said predetermined region.
Claim 11
Dependent Claim
52 words
A process for manufacturing a multilayer circuit as claimed in claim 2, further comprising the step, prior to etching said thin film layer, of depositing a layer of photoresist material over said thin film layer except for a predetermined region, said photoresist layer being used as a mask during said etching step.
Claim 12
Dependent Claim
75 words
A process for manufacturing a multilayer circuit as claimed in claim 3, further comprising the step, prior to depositing said conductive layer, of depositing a first layer of photoresist material over said base metal layer except for said predetermined region of said base metal layer; and, prior to depositing said connecting layer, depositing a second photoresist layer of said conductive layer and said first photoresist layer, except for said predetermined region of said conducting layer.
Claim 13
Dependent Claim
50 words
A process for manufacturing a multilayer circuit as claimed in claims 7, 8 or 9, wherein said converting step comprises the steps of: (a) burning off said photoresist material by heating to a temperature of 500° to 600° C.; and (b) oxidizing, at a temperature of 600° to 900° C.
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) | 1987-03-06 | 1987-09-05 | 1988-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-06 | 1991-09-05 | 1992-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-06 | 1995-09-05 | 1996-03-06 | $7700.00 | Window Closed / Lapsed |