Due to the process of soldering of electrical appliances industry and electronics industry have used solder, which a mixture of lead and tin (Sn-Pb). Lead is considered hazardous substances that affect the environment and human. The European Commission (EC) which is the authority that determines the policies and administration of the country in the European Union (EU) issued regulations used since 1 July 2006. Lead is banned in accordance with the regulations RoHs and WEEE. Result, electrical appliances industry and electronics industry is essential to developed Lead-free solder replace the lead solder and Lead-free solder must be effective more than or equivalent to the lead solder. However, in the process of Soldering, solder is not the only factor that affects the ability to soldering. Substrate and flux are affects the ability to soldering, too. That is to say, substrate, solder and flux are appropriate as a result in the ability to soldering the sheet metal parts and the strength of the joints is more.