Patent ID: 6770965
Filing Date: 2004-08-03
Classification: H01L,H05K,Y10T

Abstract:
A wiring substrate comprising:(1) an insulating substrate having an opening; at least one electronic part disposed in the opening; and an embedding resin comprising a thermoplastic resin, an acid anhydride curing agent, a curing accelerator, and a filler having a particle size of from 0.1 to 50 &mgr;m in an amount of from 51 to 74% by weight, wherein the at least one electronic part is embedded with the embedding resin which shows, before embedding, a viscosity of not higher than 85 PaÂ·s in a shear rate of 8.4 sâˆ’1 after being allowed to stand for 24 hours at 25Â° C.Â±1Â° C.; (2) an insulating layer covering the opening; (3) a terminal electrode for mounting a semiconductor element, wherein the semiconductor element is on a surface of the wiring substrate; and (4) via holes penetrating the insulating layer and connecting the terminal electrode to the embedded electronic part.