Semiconductor device mounted structure and its manufacturing method, semiconductor device mounting method, and pressing tool

A pressing tool for pressing a semiconductor device against a board with a seal-bonding resin interposed between the semiconductor device and the board, the pressing tool comprising:

• a tool body having a lower surface configured to face toward an upper surface of the semiconductor device, and to be formed larger in width than the upper surface of the semiconductor device;
• an elastic member being set on the lower surface of the tool body and having a lower surface arranged to face toward the semiconductor device;
• and
• a metal plate having a pressing surface which presses the semiconductor device and which is attached on the lower surface of the elastic member;
• wherein the pressing surface of the metal plate is configured smaller in width than the lower surface of the elastic member, and to be larger in width than the upper surface of the semiconductor device;
• and
• wherein the tool body, the elastic member and the metal plate are configured so that the pressing surface of the metal plate presses the upper surface of the semiconductor device with the seal-bonding resin and the elastic member not interposed between the lower surface of the metal plate and the upper surface of the semiconductor device, such that the elastic member covers the metal plate and the upper surface and side surfaces of the semiconductor device.