We all know that
solder paste is a viscous paste-like object composed of tin and other metal substances, fluxes, and additives. Its main function is to solder components to the corresponding positions on the PCB board. How to maintain the solder paste during use?
Solder paste is divided into lead solder paste and lead-free solder paste: the composition of lead solder paste is Sn63Pb37, its melting point is 183°C, the soldering performance is stable, and the PPM value of poor soldering is low. The composition of high temperature solder paste in lead-free solder paste is Sn/Ag/Cu, and its melting point is 217°C-227°C. The diameter of these solder paste and solder powder particles is 20-45um, which is selected according to the density between the IC pad and the pad. The distance between the IC pin pad and the pad is 0.4MM, and the diameter should be 20um-45um.
Solder paste storage requirements: It must be stored in a sealed form in a refrigerator at 2°C-10°C. The storage period of solder paste is half a year (6 months), and the principle of "first in, first out" is adhered to. the
Solder paste must be tempered at room temperature before use. The recovery time is about 3-4 hours.
After it is warmed up, stir the solder paste evenly with a machine (about 1-3 minutes), and stir it by hand for 4-6 minutes.
Unused solder paste should be classified and marked with a label, and expired or near-expired solder paste should be confirmed by relevant technical personnel before use.