With the increasing awareness of human health and global environmental protection, in order to minimize the pollution and harm of heavy metals such as lead to the environment and human beings, European and American countries Starting from July 1, 2006, lead-free electronic products were fully implemented, and China also required that electronic residential products listed in the national key supervision catalog placed on the market must not contain lead components. therefore The solder materials (solder wires, solder paste, etc.) used in electronic soldering will gradually abandon traditional tin lead alloys and adopt almost pure tin. Of course, tin without any impurities does not exist, and there is currently no international standard for lead-free A clear and unified definition is proposed by the International Organization for Standardization (ISO): the lead content in electronic assembly solder should be less than 0.1WT%. However, in lead-free solder, some copper and copper are usually added to the solder according to different product requirements Silver and other metallic substances are used to enhance the electrical connection performance of the active solder joints of tin wires.
