Substrate having a pattern of an alloy of gold and a noble and a base metal with the pattern isolated by oxides of the noble and the base metals

A method of manufacturing a wired substrate comprising the steps of providing a substrate having an insulating surface, forming a conductive layer on said insulating surface, and forming an insulating layer on said insulating surface an contiguous to said conductive pattern, wherein said conductive pattern forming and said insulating layer forming steps consist essentially of:

• forming a firstlayer of a base metal directly on said insulating layer;
• forming a second layer of palladium to a thickness of 0.025 to 0.3 micron directly on said first layer;
• forming a third layer of gold selectively directly on said second layer to a thickness which is thicker than a total thickness of said first and said second layers;
• and
• heat treating at least said first through said third layers in air at a temperature between 850.degree. C. and 950.degree. C. for a duration between 5 and 10 minutes to convert said third layer and selected portions of said first and second layers to said conductive layer and to concurrently convert remaining portions of said first and said second layers to said insulating layer, said selected portions being those portions of said first and said second layers on which said third layer is formed, said remaining portions being those portions of said first and said second layers which are other than said selected portions, said conductive layer thereby being formed of an alloy of said gold;
• said base metal, and palladium.