Method of producing substrates for semiconductor device packages comprising anchoring encapsulation to die pad

Abstract

A pre-molded leadframe includes a laminar structure having empty spaces therein and a first thickness with a die pad having opposed first and second die pad surfaces. Insulating pre-mold material is molded onto the laminar structure. The pre-mold material penetrates the empty spaces and provides a laminar pre-molded substrate having the first thickness with the first die pad surface left exposed. The die pad has a second thickness that is less than the first thickness. One or more pillar formations are provided protruding from the second die pad surface to a height equal to a difference between the first and second thicknesses. With the laminar structure clamped between surfaces of a mold, the first die pad surface and pillar formations abut against the mold surfaces. The die pad is thus effectively clamped between the clamping surfaces countering undesired flashing of the pre-mold material over the first die pad surface.