A power module structure has a heat plate for contacting a heat sink, an insulating plate soldered to the heat plate, a terminal soldered to the insulating plate and a semiconductor chip having a contact point corresponding to the terminal so as to contact the terminal through this contact point. The terminal is provided with a shock absorbing part that serves to weaken the force generated due to the difference in coefficient of thermal expansion between the terminal and the insulating plate. The terminal has a force restricting part that serves to restrict this force and is locally formed as a soldering area through which the terminal is soldered to the insulating plate. Such a structure is contained inside a base and makes a surface-contact with a heat sink to form a solid state relay.