Semiconductor device and methods of manufacturing semiconductor device

A semiconductor device comprising:

• a first board that has a first end surface and a second end surface opposite to the first end surface;
• a second board that is attached to the second end surface of the first board;
• a plurality of first electrodes that are provided on the first end surface;
• a second electrode that is provided on the second end surface and electrically coupled to an electrode of the second board;
• an internal wiring that is provided inside the first board and electrically coupled to the second electrode;
• a plurality of third electrodes that are provided inside the first board and electrically couple the first electrodes to the internal wiring;
• and
• a strain sensor that is provided inside the first board and measures a strain generated in the first board,
• wherein a linear expansion coefficient of each of the third electrodes is larger than a linear expansion coefficient of the first board,
• the first board includes a plurality of layers that are laminated,
• the linear expansion coefficient of each of the third electrodes is larger than a linear expansion coefficient of the internal wiring,
• the strain sensor is provided inside a strain sensor forming layer, the strain sensor forming layer including two insulating layers and a semiconductor layer that forms the strain sensor, the semiconductor layer being provided between the two insulating layers, and
• the plurality of third electrodes pass through one of the two insulating layers.