| 摘要 |
PURPOSE:To prevent mounting from becoming difficult due to dissipation of heat from a lead and to obtain a semiconductor element having low thermal resistance by providing a heat dissipation board with a first plane contacting with a die pad and a second plane wider than the first plane and exposed to the upper or lower surface of a package. CONSTITUTION:Since the distance l from a lead 3 to the planar part 10a of a heat dissipation board is long, heat is prevented from diffusing from the lead 3 to a heat dissipation board 10 at the time of mounting on a substrate through partial heating system and thereby mounting through partial heating system is facilitated. Thermal resistivity is lowered by 50% as compared with conventional one. Furthermore, the contact area between the heat dissipation board 10 and sealing resin 5 is increased thus blocking intrusion of water. |
