SEMICONDUCTOR DEVICE AND MANUFACTURE OF THE SAME

PROBLEM TO BE SOLVED: To obtain a semiconductor device and its manufacturing method, which are capable of coping with it in that semiconductor elements can be enhanced in density and lessened in pitch lessening their weight and restraining the effects of stresses caused by a thermal expansion difference between the semiconductor element and a wiring board. SOLUTION: A semiconductor device is equipped with a semiconductor element 12, a multilayer wiring board 13 provided with element bonding pads 16 on its element-mounting surface 13a and outer connection pads 17 on its other mounting surface 13a located opposite to its other surface 13a, and each of solder balls 14 bonded to the outer connection pads 17, where an insulating board 20A nearly equal to the semiconductor element 12 in thermal expansion coefficient is provided on the mounting surface 13b of the board 13 to be located at a position confronting the semiconductor element 12.