Patent ID: 6555763
Filing Date: 2003-04-29
Classification: H01L,H05K

Abstract:
A multilayer circuit board for a semiconductor chip module, comprising:an underlying board having a major surface made of a metal material to which a fixed potential is applied; insulating layers which are stacked on the major surface of said underlying board and having wiring layers formed on surfaces of said insulating layers; fixed-potential wiring layers forming part of the wiring layers formed on said insulating layers; via holes formed below said fixed-potential wiring layers to extend through said insulating layers; and metal layers filled in the via holes so as to make upper ends of said metal layers be connected to lower surfaces of said fixed-potential wiring layers, wherein a first of said insulating layers is in contact with the major surface of said underlying board having a first metal layer formed therein, and a lower end of the first of said metal layers is in contact with the major surface of said underlying board, and wherein a second insulating layer is formed on said first insulating layer and a lower end of a second metal layer is in contact with an upper surface of said fixed-potential wiring layer of said first insulating layer, and wherein a gold layer is situated between said second metal layer and said surface of said underlying board.