Power semiconductor device

A power semiconductor device comprising:

• a metallic lead frame that has main surfaces opposite to each other, one of which being a mounting surface and the other of which being a dissipating surface, and including a P-potential electrode, intermediate potential electrodes, and an N-potential electrode, which are electrically independent;
• a switchable power semiconductor chip and a current detection resistor joined to the mounting surface of the lead frame via a conductive joining member;
• a wiring member that connects an electrode of the power semiconductor chip to a portion of the lead frame;
• and
• a resin that covers a portion of the mounting surface of the lead frame, the power semiconductor chip, the resistor and the wiring member,
• wherein the P-potential electrode includes:
• a chip mounting portion in which the mounting surface with two or more of the power semiconductor chips joined thereto is placed within the resin;
• and a first heat mass portion that is provided adjacent to the chip mounting portion and placed external to the resin.