Multilayer ceramic circuit substrate, process for producing the same, and electrically conductive material for use in multilayer ceramic circuit substrate

摘要

A multilayer ceramic circuit substrate having therein internal conductor patterns comprising W and/or Mo as a main component and surface conductor patterns comprising Cu as a main component formed onto a surface layer of the multilayer ceramic circuit substrate, wherein an intermediate metal layer comprising 40 to 90 wt. % of W and/or Mo and 10 to 60 wt. % of at least one element selected from the group consisting of Ir, Pt, Ti, and Cr is formed in through-holes of the surface layer and on parts of the surface layer in the vicinity of the through holes on the surface layer, whereby the internal conductor patterns and the surface conductor patterns are electrically connected through the intermediate metal layer. The alumina multilayer ceramic circuit substrate provides an excellent bonding strength and electrical conductivity between the internal conductors and the surface conductors and enables high precision wiring and miniaturization of an electronic circuit part.