Metal content of solder paste, the oxidation of metal powder, metal powder can affect the size of the beads.
A. the metal content of solder paste
Solder paste is the metal content in its quality ratio is about 88% ~ 88%, volume ratio of about 50%. When metal content increases, the solder paste viscosity increase, can effectively resist the force created by the preheating process of vaporization. The increase of metal content, make the metal powder is arranged closely, so that it can be easily combined with during melting and not be blown away. In addition to the increase of metal content may also reduce the solder paste printing after "collapse", therefore, is not easy to produce soldering tin beads.
B. solder paste the degree of oxidation of the metal powder
Metal powder is the higher the degree of oxidation of solder paste, powder metal ? when welding