Semiconductor device

A semiconductor device comprising:

• an insulation substrate including an insulation layer and a first electrode pattern provided on the insulation layer;
• a semiconductor element provided on the first electrode pattern;
• a case surrounding the insulation substrate;
• and
• a sealing member covering each of the insulation substrate and the semiconductor element, wherein
• the first electrode pattern includes a first body portion and a first step portion protruding from the first body portion,
• the first body portion has
• a first surface facing the insulation layer,
• a second surface located opposite to the first surface and facing the semiconductor element, and
• a first side surface contiguous to the second surface,
• the first step portion has
• a third surface contiguous to the first surface and facing the insulation layer, and
• a first step surface located opposite to the third surface and contiguous to the first side surface,
• in a cross section perpendicular to the second surface, the first side surface has a curved shape,
• in the cross section perpendicular to the second surface,
• a boundary between the second surface and the first side surface is defined as a first boundary,
• a boundary between the first side surface and the first step surface is defined as a second boundary, and
• a length of a line segment connecting the first boundary and the second boundary is defined as a first length,
• a length of the first side surface in the cross section perpendicular to the second surface is longer than the first length, and
• the first step surface has a planar shape.