Substrate with low-elasticity layer and low-thermal-expansion layer

Abstract

A substrate for mounting an IC chip including a printed substrate including a first build-up layer. The first build-up layer including (i) a first conductor layer having first conductor circuits and (ii) a resin insulating layer. The first conductor circuits and the resin insulating layer alternating along a length of the first build-up layer. A low-elasticity resin layer formed on the first build-up layer. A low-thermal-expansion substrate formed of ceramics or silicon, and provided on the low-elasticity resin layer. Through-hole conductors provided through the low-thermal-expansion substrate and the low-elasticity resin layer; and second conductor circuits formed on the low-thermal-expansion substrate. The through-hole conductors electrically connect the first conductor layer and the second conductor circuits provided on the low-thermal-expansion substrate.