Semiconductor device with reverse and observe surfaces

A semiconductor device comprising:

• a semiconductor element;
• a first lead on which the semiconductor element is mounted;
• and
• a sealing resin covering the semiconductor element and a part of the first lead,
• wherein the first lead includes:
• a first obverse surface to which the semiconductor element is bonded;
• a first reverse surface facing away from the first obverse surface in a thickness direction of the first lead and exposed from the sealing resin;
• and
• an internal reverse surface facing a same side as a side that the first reverse surface faces in the thickness direction and covered with the sealing resin,
• the internal reverse surface is offset toward the first obverse surface with respect to the first reverse surface in the thickness direction, and an irregular portion is provided in the internal reverse surface.