METHOD OF PRODUCING SUBSTRATES FOR SEMICONDUCTOR DEVICES, CORRESPONDING SUBSTRATE AND SEMICONDUCTOR DEVICE

A pre-molded leadframe is produced starting from a sculptured, electrically conductive laminar structure (10) having empty spaces therein and having a first thickness (D1) with one or more die pads (10) having a first die pad surface (10A) for mounting semiconductor chips as well as a second die pad surface (10B) opposite the first die pad surface (10A). Insulating pre-mold material (12) is molded onto the laminar structure (10) clamped between a pair of planar clamping surfaces (TPS, BPS) kept at a distance equal to the thickness (D1). The pre-mold material (12) penetrates into the empty spaces and provides a laminar pre-molded substrate (10, 12) having the first thickness (D1) with the first die pad surface (10A) left exposed by the pre-mold material (12). The die pad (10) has a second thickness (D2) between the first die pad surface (10A) and the second die pad surface (10B) that is less than the first thickness D1 so that, when clamped between the clamping surfaces (TPS, BPS) the first die pad surface (10A) abuts against the first clamping surface (TPS) and the second die pad surface (10B) is at a distance from the second clamping surface (BPS). One or more pillar formations (100) are provided protruding from the second die pad surface (10B) of a height equal to the difference between the first thickness (D1) and the second thickness (D2). With the laminar structure (10, 14) clamped between the clamping surfaces (TPS, BPS) the pillar formation(s) abut against the second planar clamping surface (BPS). The die pad (10) is thus effectively clamped between the clamping surfaces (TPS, BPS) countering undesired flashing of the pre-mold material (12) over the first die pad surface (10A) .