| 摘要 |
PURPOSE:To avoid fluctuation of electronic characteristics of electronic parts by a method wherein a buried member whose linear expansion coefficient is different from the linear expansion coefficient of a resin layer is buried in the surface part of the resin layer. CONSTITUTION:An IC chip 2 and an island 3 are molded as a whole with a resin layer 4 made of molding resin such as epoxy system resin. A buried member 5 made of a material such as copper, iron, nickel and ceramic which has a linear expansion coefficient alpha1 smaller than the linear expansion coefficient alphaM of the molding resin of the resin layer 4 is buried in the upper surface part of the resin layer 4. When an IC package 1 is taken out of a molding die and cooled down to a room temperature, the resin layer 4 is contracted. As the thermal linear expansion coefficient alpha1 of the buried member 5 is smaller than the thermal linear expansion coefficient alphaM of the resin layer 4, both ends of the resin layer 4 is warped downward and the center of the curvature of the warpage is positioned below the lower surface of the resin layer 4. With this constitution, the tensile stress induced in the resin layer 4 by the warpage is cancelled with the compression stress in the resin layer 4 so that the pressure applied to the IC chip 2 can be reduced and the fluctuation of electric characteristics can be avoided. |
