Metallized ceramic substrate having smooth plating layer and method for producing the same

摘要

A metallized ceramic substrate having a smooth plating layer, comprising a ceramic substrate comprising aluminum nitride as a main component; a tungsten- and/or molybdenum-based metallized layer formed on at least one face of the ceramic substrate and a nickel-based plating layer which is formed on the metallized layer and has a thickness of not greater than 2 mu m and a surface roughness (Ra) of not greater than 2 mu m. In another aspect, the plating layer may be constituted of a first nickel-based plating layer and a second gold-based plating layer in which the first plating layer and the second plating layer have a thickness of not greater than 2 mu m and a thickness of not greater than 1 mu m, respectively, and the surface roughness (Ra) of the second layer should be 2 mu m or less. These metallized substrates are produced by applying a metallizing paste of W and/or Mo onto a green AlN ceramic substrate, flattening, firing and forming the foregoing plating layer or layers.