Lead molding device for semiconductor device

Abstract

Abstract PURPOSE:To prevent the lift of each end of external leads which develops due to warp in a resin sealing part by establishing molding faces of the respective ends both in a die and a punch in such a way that inclined faces in central parts of the above molding faces are set at a slightly shallow angle in comparison with both end parts of the above molding faces according to warp which is shaped in the recessed form of the resin sealing part. CONSTITUTION:A die 10 is composed of following members: a recessed hole 2 of a resin sealing part which is slightly larger than the external shape of the resin sealing part that is to be mounted in a semiconductor device; a protrusion 1 having side face parts 3 which clamp the base of external leads 7 in cooperation with pads; a lead molding face block 6 where the protrusion 1 is placed on an upper face and each lead molding face 5a having a small angle with respect to top flat part of the protrusion 1 as well as each lead molding face 4a having a large angle are formed so that they may come into contact with each central lower edge of the side face parts 3. A punch 20 is equipped with lead molding faces 4b and 5b having the same angles as those of the lead molding faces 4a and 5a of the die 10. Differences in angles of two lead molding faces 4a and 5a are determined on the basis of empirical data of warp which develops at the resin sealing part. Molding is thus performed so that the flatness with respect to the plain face of each lead pointed end is kept constant.

Inventors

• 👤 Kojiro Shibuya
• 👤 渋谷　幸二郎

Bibliographic Details