To provide a semiconductor device which has high heat dissipation efficiency and ensures high connection reliability by preventing connection defect and the occurrence of damage due to thermal stress.

A rolled material such as aluminum and copper of good conductivity is punched on a semiconductor substrate 1, and a connector 3 which is subjected to bending processing is fixed thereto by a solder 2. The bottom surface of the recess of the connector 3 is a constraint region 4 fixed by the solder 2, and the upper part of the connector 3 is a non-constraint region 5 which is not fixed by the solder 2. Since the constraint region 4 of the connector 3 which functions as a spring in the non-constraint region 5 is fixed by the solder 2 on the semiconductor substrate 1, thermal stress generated inside the solder 2 due to the difference of thermal expansion efficient between the connector 3 and the semiconductor substrate 1 is reduced by the spring function of the connector 3, and connection reliability is improved. At the same time, heat dissipation function is improved.

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