Copper-based solder paste is made of alloy solder powder with copper and phosphorus as the main elements, adding active flux and binder independently developed by Fujing. It has the characteristics of good fluidity and excellent process performance. In addition, the addition of silver to the copper-phosphorus alloy will greatly increase the solder wetting ability, increase the strength and toughness, and lower the melting point. This kind of solder has a low brazing temperature and has a self-brazing effect.
Phosphorus-containing copper-based solder paste is suitable for brazing red copper, copper alloys, silver alloys, etc. The solder paste has good wettability with the base metal to be welded, and the welding strength is excellent. However, phosphorus-containing copper-based solder paste has poor wettability to metal alloys such as iron or nickel, and it is easy to form brittle phosphides at the joint, which increases the brittleness of the joint. It is recommended to use other types of solder paste.