REFORMING OF INSULATING SUBSTRATE FOR MOUNTING SEMICONDUCTOR

摘要

PROBLEM TO BE SOLVED: To improve reliability to heat cycle of an insulating substrate by making the deformation resistance of a metal layer small. SOLUTION: A metal layer 13 is formed on a portion or whole of the surface of a ceramic substrate 11 and then the insulating substrate is heat treated at a temp. of 0.3Tm to Tm under vacuum or an inert gas atmosphere for 0.5 to 5 h, when the melting point of the metal layer 13 is set as Tm expressed in terms of the absolute temp. It is preferable that the metal layer 13 is formed on the ceramic substrate 11 by brazing the metal layer 13 onto the ceramic substrate 11 through a brazing foil 12. It is further preferable that the brazing foil 12 is an Al-Si foil and the metal layer 13 is an aluminum layer.