Substrate and process for producing the same

Abstract

The present invention produces the following substrate and the following process for producing the substrate. A substrate obtained by filling through holes in a sintered product of aluminum nitride with an electrically conducting layer, wherein said sintered product of aluminum nitride has a thermal conductivity of not smaller than 190 W/mK, and the adhesion strength between said sintered product of aluminum nitride and said electrically conducting layer is not smaller than 5.0 kg/mm2. A process for producing the substrate comprises: filling the through holes in a molded article of aluminum nitride comprising an aluminum nitride powder, a sintering assistant and an organic binder, with an electrically conducting paste comprising 100 parts by weight of a refractory metal powder and 2 to 10 parts by weight of an aluminum nitride powder; dewaxing the molded article of aluminum nitride so that the content of residual carbon therein is within a range of from 800 to 3000 ppm; and firing the molded article of aluminum nitride at a temperature of from 1200 to 1700° C. and, then, at a temperature of from 1800 to 1950° C.

Dependencies are inferred from the claim text.