A piston for an internal combustion engine, has a lower piston part and an upper piston part disposed on the lower piston part. The invention may also be used in other types of data networks, using packet switched traffic, e. The semiconductor device includes a gate electrode layer, a gate insulating film over the gate electrode layer, an oxide semiconductor stacked film overlapping with the gate electrode layer with the gate insulating film provided therebetween, and a pair of electrode layers in contact with the oxide semiconductor stacked film. 0 wt % of at least one type of rare earth element ; firstly melting the active solder at a temperature lower than 450\xb0 C. Based on the results of inspection, the setting value of the refresh period of the word line is determined and written in the RAM to set the word line based refresh period.