Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
217 words
A method for manufacturing a multilayer circuit substrate comprising the steps of: providing an insulating substrate formed of an inorganic oxide and supporting a laminate formed by alternately laminating wiring pattern layers of copper and insulating layers of an inorganic oxide material, said laminate having as an uppermost layer a wiring pattern layer formed of copper and wherein said laminate comprises a lowermost wiring layer contacted with the substrate, and the lowermost wiring layer is formed by the steps of (a) forming a first thin copper film on the insulating film, (b) oxidizing the first thin copper film to convert it into a copper oxide layer, (c) forming a second thin copper film thicker than the first thin copper film on the copper oxide layer, (d) selectively removing by photoetching the copper oxide layer and the second thin copper film, and (e) heating the remaining copper oxide layer at a temperature sufficient to react with the substrate; forming by a low temperature deposition a layer of an electrically conductive material capable of being subjected to wire bonding on substantially the entire upper surface of the laminate; and selectively removing by photoetching the electrically conductive material layer to allow only the portion connected to the copper wiring pattern layer forming the uppermost layer of the laminate to remain.
Claim 2
Independent Claim
217 words
A method for manufacturing a multilayer circuit substrate comprising the steps of: providing an insulating substrate formed of an inorganic oxide and supporting a laminate formed by alternately laminating wiring pattern layers of copper and insulating layers of an inorganic oxide material, said laminate having as an uppermost layer a wiring pattern layer formed of copper and wherein said laminate comprises a lowermost wiring layer contacted with the substrate, and the lowermost wiring layer is formed by the steps of (a) forming a first thin copper film on the insulating film, (b) oxidizing the first thin copper film to convert it into a copper oxide layer, (c) forming a second thin copper film thicker than the first thin copper film on the copper oxide layer, (d) selectively removing by photoetching the copper oxide layer and the second thin copper film, and (e) heating the remaining copper oxide layer at a temperature sufficient to react with the substrate; forming by a low temperature deposition a layer of an electrically conductive material capable of being subjected to wire bonding on substantially the entire upper surface of the laminate; and selectively removing by photoetching the electrically conductive material layer to allow only the portion connected to the copper wiring pattern layer forming the uppermost layer of the laminate to remain.
Claim 3
Dependent Claim
27 words
The method according to claim 1, wherein said insulating layer is formed by printing a paste of the inorganic oxide material and baking in a neutral atmosphere.
Claim 4
Dependent Claim
29 words
The method according to claim 1, wherein said wiring layer formed after the lowermost wiring layer is formed by printing a copper paste and baking in a neutral atmosphere.
Claim 5
Dependent Claim
99 words
The method according to claim 1, wherein said wiring layer formed after the lowermost wiring layer is formed by the steps of (a) forming a first thin copper film on the insulating layer, (b) oxidizing the first thin copper film to convert it into a copper oxide layer, (c) forming a second thin copper film thicker than the first thin copper film on the copper oxide layer, (d) selectively removing by photoetching the copper oxide layer and the second thin copper film, and (e) heating the remaining copper oxide layer at a temperature sufficient to react with the substrate.
Claim 6
Dependent Claim
36 words
The method according to claim 1, wherein a layer of metallic material having free energy of formation of oxide higher than that copper is formed between the uppermost copper wiring layer and its underlying insulating layer.