Method of manufacturing a semiconductor device

Abstract

A semiconductor device improved in packaging reliability is disclosed. Each of leads used in the semiconductor device has a first surface positioned between a main surface of a resin sealing body and a back surface opposite to the main surface of the resin sealing body, a second surface positioned on the side opposite to the first surface and exposed from the back surface of the resin sealing body, a first end face positioned on a semiconductor chip side, a second end face positioned on the side opposite to the first end face and exposed from a side face of the resin sealing body, and a recessed portion depressed from the second surface to the first surface side and contiguous to the second end face, the second surface and an inner wall surface of the recessed portion being covered with a plating layer which is higher in solder wettability than the second end face of each of the leads.

1 - 26 . (canceled) 
     
     
         27 . A method of manufacturing a semiconductor device, comprising: a step for providing a lead frame including a semiconductor chip and leads, the semiconductor chip and the leads being sealed with a sealing body, wherein each of the leads has a first surface that extends inside and outside of the sealing body and that projects from a side face of the sealing body, and a second surface positioned opposite the first surface, the second surface being exposed from a back surface of the sealing body and having a plurality of indented portions formed therein, the indented portions being formed from the second surface toward the first surface and being spaced from each other along a projecting direction of the first surface;
 a step for forming a plating layer over the first surface outside the sealing body, the second surface, and an inner wall surface of the indented portions of each of the leads, the plating layer being higher in solder wettability than each of the leads; and   a step for cutting each lead such that at least one indented portion thereof and at least part of another indented portion thereof are exposed from the resin sealing body after the cutting.   
     
     
         28 . A method according to  claim 27 ,
 wherein said first surface has a first portion covered by said sealing body and a second portion that projects outside said sealing body, and   said plating layer is formed over said second portion.   
     
     
         29 . A method according to  claim 27 , wherein said step for forming a plating layer is after forming the sealing body. 
     
     
         30 . A method according to  claim 27 ,
 wherein the lead frame is comprised of one of Cu, Cu alloy, and Fe—Ni,   wherein the sealing body is comprised of a biphenyl-based thermosetting resin with a phenolic curing agent and silicone rubber and filler incorporated therein, and   wherein the plating layer is comprised of Sn—Bi.   
     
     
         31 . A method according to  claim 27 , wherein said step for cutting is performed such that two indented portions of each lead are exposed from the sealing body after the cutting.