Semiconductor device and method of making the same

A semiconductor device comprising:

• a semiconductor chip;
• a die-pad including an upper surface on which the semiconductor chip is mounted and a lower surface opposite to the first surface, the die-pad being electrically connected to the semiconductor chip via a first wire;
• a plurality of leads spaced from the die-pad via a clearance and electrically connected to the semiconductor chip via second wires;
• and
• a sealing resin enclosing the semiconductor chip in a manner such that the lower surface of the die-pad is exposed;
• wherein the die-pad includes a thin-walled portion formed by removing a part of the lower surface along a peripheral edge of the die-pad, the die-pad being formed with at least one slit extending through the thin-walled portion,
• the at least one slit is located inwardly from the clearance and between the peripheral edge of the die-pad and the semiconductor chip,
• the semiconductor chip has a side facing the at least one slit and extends from a first corner of the chip to a second corner of the chip, and
• the at least one slit is formed along the side of the chip and extends continuously from a first position that is closer to the first corner of the chip than to the second corner of the chip.

A semiconductor device comprising:

• a die-pad including a first surface, a second surface opposite to the first surface, and a peripheral edge, the second surface including an exposed portion and a retreated portion around the exposed portion;
• a semiconductor chip mounted on the first surface of the die-pad, the chip having a first side and a second side adjoining the first side to define a corner between the first and second sides;
• and
• a sealing resin covering the die-pad and the semiconductor chip, the resin allowing the exposed portion to be exposed and being held in contact with the retreated portion,
• wherein the die-pad is formed with first and second slits each of which is open in the retreated surface of the second surface and in the first surface,
• the slits are being located between the peripheral edge of the die-pad and the semiconductor chip,
• the first slit facing and extending along the first side of the semiconductor chip, the second slit facing and extending along the second side of the semiconductor chip, and
• wherein the first and second slits are discontinuous with each other at the corner of the chip.