The temperature requirement of lead-free solder wire is higher than that of lead-free solder wire. The appearance of wire solder joints is relatively rough, there are many pores in the solder joints, and the requirements for wetting angle are relatively large. Without half-moon-shaped lead-free solder wire, the requirements for additives are relatively high. It is necessary to increase the activity of additives and increase the requirements for activation temperature. .

The supply of tin raw materials for lead-free solder wires is currently limited. The primary problem faced by replacing leaded solder bars with lead-free solder wires is the supply of tin raw materials. At present, the annual output of solder wire in the world is 230,000 tons, which is widely used in metal connection and surface treatment and plating. The world's annual output of tin, the main component of lead-free solder wire, is 210,000 tons, of which 60,000 tons are used as raw materials for solder wire. According to the calculation that ordinary tin accounts for 60% of the soldering estimate, the annual output of new solder wire should be 100,000 tons, and the remaining 130,000 tons are solder wires that are reused from residues. Lead-free solder wire cannot be made from lead-containing solder wire, so it must be made of raw tin.