Patent ID: 8264079

Claim:
A semiconductor device mounting method comprising: placing a semiconductor device on a semiconductor device mounting area of a board with a seal-bonding resin interposed therebetween; with use of a pressing tool including a pressing member formed of a rigid material having a flat surface formed larger in planar shape than the semiconductor device, and an elastic member set around the flat surface of the pressing member, pressing an upper surface of the semiconductor device by the flat surface of the pressing member so that device electrodes of the semiconductor device and board electrodes of the board are connected to each other via bump electrodes, respectively, while an opposing area between the semiconductor device and the board is sealed with the resin and, concurrently, part of the resin is pushed and expanded outward of the opposing area so that the resin expanding outward of the opposing area is filled into a space surrounded by the flat surface of the pressing tool, the elastic member and side faces of the semiconductor device outside the corner portions of the semiconductor device; and thereafter, heating and hardening the resin so that a fillet portion, which is an expanding portion of the seal-bonding resin outward of the opposing area between the semiconductor device and the board, is formed outside the opposing area, thereby forming a mounted structure of the semiconductor device in which entire side faces at least of the corner portions of the semiconductor device are covered with the fillet portion while a flat surface is formed at a top portion of the fillet portion so as to extend along an upper surface of the semiconductor device.