1. Distinguish product positioning and differentiate treatment
①The product has high added value and high stability requirements, so choose high-quality solder paste (R-grade).
② If it is exposed to the air for a long time, anti-oxidation (RA grade) is required.
② For low-end products and consumer goods, those who do not have high requirements for product quality, choose solder paste (RMA) with similar quality and low price.
2. Device material and PCB pad material
①The solder paste of 63Sn/37Pb should be selected if the material of the PCB pad is lead tin-plated.
② Devices with poor solder ability should use 62Sn/36Pb/2Ag.
3. Different choices of different processes
① Lead-free process generally chooses Sn-Ag-Cu alloy solder.
②No-clean products choose weak corrosive no-clean solder paste.
4. Welding temperature
①The soldering of thermal devices with poor high temperature resistance should choose low melting point solder paste containing Bi.
②High temperature components must choose high melting point solder paste.