| 摘要 |
PURPOSE:To improve adhesion between a first resin sealing part and a second sealing part, to enhance the reliability of a semiconductor device against mechanical shocks and to obtain a stable heat dissipation characteristic, by providing a cutout or a through hole in the first resin sealing part, and forming a tapered or stepped part, which is to become an undercut, in the cutout or the through hole with respect to the second resin sealing part. CONSTITUTION:A bottom force cavity has a projection, which supports a part 2d of inner leads. A top force cavity has a projection, which corresponds to said projection of the bottom force and has a tapered part 21. A forming die constituted by said cavities is used. A back surface 2c is closely contacted with the surface of the bottom force cavity so that the back surface 2c of a chip mounting part of a lead frame is exposed at the first resin sealing part. Thus transfer molding is performed. Then an inside 16c of the cutout in the first resin sealing part is filled with an epoxy resin. The tapered part 21 of the cutout 20 has an inverted tapered shape (desirably 5 deg. or more, and more desirably 10 deg. or more) with respect to the second resin sealing part. Therefore, adhesion an interface 22 between the first resin sealing part and the second resin sealing part is improved. |
