Semiconductor device having a heat spreader exposed from a seal resin

A semiconductor device comprising:

• a first wiring board formed on a substrate and having an opening through which a surface of the substrate is exposed;
• a semiconductor element located in the opening and having a back surface opposite to a circuit formation surface, the back surface being bonded to said substrate;
• bonding wires which connects electrodes formed on said first wiring board to first electrodes arranged in a peripheral part of the circuit formation surface of said semiconductor element;
• a second wiring board facing the circuit formation surface of said semiconductor element and having connection members which are connected to second electrodes arranged in a center part of said circuit formation surface;
• first external connection terminals formed on said second wiring board and electrically connected to said connection members;
• and
• second external connection terminals formed on said first wiring board and having second external connection electrodes electrically connected to said first electrodes of said semiconductor element through wirings of said first wiring board and said bonding wires.