| 摘要 |
PURPOSE:To enhance the adhesion of a lead frame and a die and to suppress thin and thick burrs due to the leakage of a resin by respectively interposing heat-resistant elastomers on the pressure holding surfaces of upper and lower dies directly brought into contact with the lead frame. CONSTITUTION:Flat plate-shaped heat-resistant elastomers 4 are respectively provided to the pressure holding surfaces 7 adjacent to the cavity part 5 of the upper and lower dies 1a, 1b of an encapsulation die and the lead frame 2 connected to a semiconductor element 3 electrically is pressed by this mold. At this time, the pressing of the lead frame by the encapsulation mold is performed through heat-resistant elastomers 4 and metals are not brought to a mutual direct contact state. The heat-resistant elastomers 4 are formed, for example, by using silicone rubber and closely adhered to the lead frame to make it possible to embed the unevenness of the surface part of the lead frame. This unevenness is generated because the lead frame is prepared by punching processing and the surface of the lead frame sag in the vicinity of a processed part by shearing force and burrs protrude from the rear of said frame. Since the heat-resistant elastomers 4 are pressed to be closely adhered to the surface of the lead frame, the leakage of a resin is eliminated. |
