When welding copper (Cu) foundation, it is not easy to produce resistance heat energy due to the small resistance and good thermal conductivity of copper base metal. If in order to increase the temperature of the resistance heating, and increase the current blindly, there will be before the temperature of the welding joint surface rises, the electrode and the base metal of the welding workpiece will be fused and bonded together first, which can not achieve the predetermined welding. Therefore, in the welding of copper based metals, the metal elements with high melting point and high resistivity (more than 3 times of copper) such as tungsten (W) and molybdenum (MO) are usually added to the electrode. In this way, when the current passes through the electrode, the electrode itself heats up (800 ~ 900℃), and transfers the heat energy to the workpiece to make it hot, thus making the welding process easier.