Patent ID: 7829992

Claim:
A semiconductor device, comprising: a first resin substrate on which a first semiconductor chip is mounted; a second resin substrate on which a second semiconductor chip is mounted; and a resin spacer, contacted with a front surface of said first resin substrate and to a back surface of the second said resin substrate, so that said front first resin substrate is electrically connected to said second resin substrate, wherein said resin spacer is disposed in a circumference of said first semiconductor chip on the surface of said first resin substrate, wherein said first semiconductor chip is disposed in a space section provided among said first resin substrate, said second resin substrate and said resin spacer on the surface of said first resin substrate, wherein said first resin substrate includes a buildup layer, which is formed of insulating layers containing resin and conductor interconnect layers that are alternately stacked, each of said conductor interconnect layers being electrically mutually coupled via conductor layers formed in the via holes of said insulating layers, wherein said second resin substrate includes a buildup layer, which is formed of insulating layers containing resin and conductor interconnect layers that are alternately stacked, each of said conductor interconnect layers being electrically mutually coupled via conductor layers formed in the via holes of said insulating layers, and wherein, among insulating layers of said buildup layer of at least one of said first resin substrate and said second resin substrate, in at least one insulating layer, an average coefficient of thermal expansion along a substrate inplane direction for temperature range of from 25 degree C. to a glass transition point thereof is equal to or lower than 30 ppm/degree C., and an average coefficient of thermal expansion along a substrate thickness direction for temperature range of from 25 degree C. to a glass transition point thereof is equal to or lower than 30 ppm/ degree C.