ELECTRONIC SEMICONDUCTOR DEVICE PACKAGE STRUCTURE AND METHOD

摘要

A NEGATIVE LOCKING SIDE WALL (14) TO PROVIDE BOTH MOULD LOCKING AND A MOISTURE BARRIER IS PROVIDED SURROUNDING A RECESSED AREA (3) IN A FLAG PORTION (15) OF A LEADFRAME. A SEMICONDUCTOR DIE (10) IS MOUNTED ON A BASE AREA (24). THE DIE (10) IS ENCAPSULATED IN PLASTICS COMPOUND (29), WHICH FLOWS INTO THE RECESSED AREA (3) BEFORE SETTING. THE NEGATIVE LOCKING SIDE WALL (14) IS MADE BY FIRST PUNCHING THE RECESSED AREA (3) INTO THE FLAG PORTION OF THE LEADFRAME USING A RECTANGULAR PUNCH AND THEN PUNCHING THE TOP OF THE SIDE WALLS (14) AT AN ANGLE SLOPING TOWARDS THE CENTRE OF THE BASE AREA (24), CAUSING THE LEADFRAME MATERIAL AT THE TOP TO DEFORM AND OVERHANG THE EDGE OF THE BASE AREA (24). WHEN THE PLASTICS COMPOUND IS SET, IT IS ''LOCKED'' IN BY MEANS OF THE TOP PART OF THE SIDE WALL (14) OVERHANGING THE BOTTOM PART AND THE SHARP BOTTOM CORNER PROVIDES A MOISTURE BARRIER. (FIG. 3)