Patent ID: 8664779

Claim:
A semiconductor device comprising: a semiconductor chip, a function element being formed on a side corresponding to a front surface of the semiconductor chip; a front side resin layer formed on the front surface of the semiconductor chip, the front side resin layer having a thermal expansion coefficient of between 2.5 and 8.5 ppm/° C.; and a back side resin layer formed on a back surface of the semiconductor chip, the back side resin layer being formed to be thinner than the front side resin layer, wherein the front side resin layer has a thickness more than four thirds that of a thickness of the back side resin layer, wherein the back side resin layer is a non-active layer devoid of any functional element on an outer surface thereof, the back side resin layer having a thermal expansion coefficient between 60/8.5 and 60/2.5 times that of the front side resin layer, wherein a groove is formed on the back side resin layer, and a plurality of external terminals are formed on the front side resin layer, wherein end surfaces of the front side resin layer and the back side resin layer are flush with a side surface of the semiconductor chip, and wherein there is no warp in the semiconductor chip.