The reliability of the PCB assembly link depends on the reliability of the device, the PCB, and the solder joint. Due to the use of free solder, Sn increases the oxygen content in the alloy, making it easier to generate tin whiskers.Whiskers growing from weak oxide layers can cause short-circuit of adjacent pins or adversely affect the high-frequency performance of high-frequency circuits.

Cashless solder usually requires a higher welding temperature than tin-lead solder, and the sensitivity to welding temperature varies from device to device.For example, ceramic capacitors are sensitive to the rate of temperature change, but they are not sensitive to the actual temperature.Aluminum electrolytic capacitors, on the other hand, are very sensitive to the temperature itself.At higher temperatures, there are more effects in the linking part and the plastic package part, such as lamination, cracking, deformation and warping, but Kendall hole is the interface weakening.Therefore, there are more requirements for thermal thermal front soft brazing.

Also associated with lead-free welding are Flip chips that use lead-free bumps or cold fall and GSP wafer-level packages.The higher welding temperature and strength of lead-free solder may adversely affect the reliability of low-k dielectric materials on the chip.Low K dielectric materials are mainly adopted for high speed processing applications, but generally speaking, they are fragile and crack easily.The higher welding temperature of the lead-free Flip Chip in the primary package adversely affected the substrate of the device, similar to the welding assembly process in the secondary package.