Verfahren zur Herstellung eines Keramik-Leitersubstrates sowie Keramik-Leitersubstrat

摘要

A ceramic circuit substrate providing a circuit pattern with a fine line as well as high accuracy for positioning the circuit pattern and a method of producing the ceramic circuit substrate. An alumina layer that is green containing an alumina that is not sintered at a temperature ranging from 800 DEG to 1000 DEG C. is applied on a surface of a ceramic green sheet containing glass and then fired at a temperature ranging from 800 DEG to 1000 DEG C. The ceramic green sheet is sintered into a sintered ceramic substrate. A porous alumina layer is formed on a surface of the sintered ceramic substrate. The glass contained in the sintered ceramic substrate is caused to flow to the inside of the porous alumina layer so that the part of the porous alumina layer filled with the glass is bonded to the sintered ceramic substrate. The part of the porous alumina layer not filled with the glass is removed, wherein the porous alumina layer remaining on the sintered ceramic substrate after the removing has a thickness of 10 mu m or less. A paste for forming the circuit pattern is printed on a surface of the part of the porous alumina layer that has been bonded to the sintered ceramic substrate for heating.