| 摘要 |
<p>PURPOSE:To enable moisture to be mainly absorbed by a moisture absorbing material as long as it stays working by a method wherein the moisture absorbing material much higher than a sealing resin in moisture absorbing property is bonded to the rear of the die pad exposed due to a vent hole. CONSTITUTION:A semiconductor element 1 is fixed to a die pad 2a by bonding, a wiring pad 3 is connected to an inner lead 2b with a wire 4, all are sealed up with a sealing resin 5, and an outer lead 2c is formed. A vent hole 6 is provided to the rear center of the die pad 2a opposite to its die mounting side. A moisture absorbing material 7 much higher than a sealing resin 5 in moisture absorbing property is bonded to the rear of the die pad exposed due to the vent hole 6. As the moisture absorbing material 7 whose moisture absorbing property is much higher than that of the sealing resin 7, moisture contained in the air is absorbed by the moisture absorbing material 7 and hardly absorbed by the sealing resin 5. Until the amount of moisture exceeds the moisture absorbing capacity of the moisture absorbing material 7, moisture concentrates on the moisture absorbing material 7 provided to the rear of the pad, so that the rapid thermal expansion of moisture caused by soldering heat is centered on a vent hole provided to the rear of a die pad, in result the vent hole works most effectively.</p> |
