| 摘要 |
PURPOSE:To enhance protecting performance against the outside atmosphere, and moreover to reduce thermal resistance of the package for the semiconductor device by a method wherein the containing rate of fillers of the outside surface layer of the package is made smaller than the inside layer. CONSTITUTION:Tablets 21, 22 using a molding material consisting of SiO2 as fillers and epoxy resin as a base are used, and the containing rate of fillers is made respectively to 30%, 75-80%. The tablet 22 is stacked on the tablet 21 to be heated at about 180 deg.C, and when they are pressed by a plunger 23, the material 21 came before in caves 25 is expanded by the following material 22 to come in contact with the wall faces of the caves, and the outside surface layer 17 is formed on the material 21 and the inside layer 16 is formed of the material 22. According to the construction thereof, the protecting effect against the outside atmosphere is enhanced by the layer 17, disadvantage of the thermal resistance rise according to favorable thermal conductivity of the inside layer 16 is compensated by the outside layer 17, and the favorable package can be obtained. |
