PCB manual welding

　　① Check the insulation materials in advance before welding, and there should be no burns, scorches, deformation, cracks and other phenomena, and do not allow burns or damage to components during welding.

　　The welding temperature should usually be controlled at about 260 ° C, not too high or too low, otherwise it will affect the welding quality.

　　③ The welding time is usually controlled within 3s. For welding parts with large heat capacity such as multi-layer plates, the entire welding process can be controlled within 5s; For the welds of integrated circuits and thermal components, the entire process should not exceed 2s. If it is not welded well within the specified time, it should be re-welded after the welding joint has cooled, and the quality standard of re-welding should be the same as that of the welding joint during a single welding. Obviously, due to the differences in the power of the soldering iron, the heat capacity of the solder joint and other factors, the actual grasp of the heat of the welding, there is no rule to follow, and specific conditions must be treated specifically.

　　④ When welding, adjacent components and printed boards should be prevented from being affected by overheating, and necessary heat dissipation measures should be taken for heat-sensitive components.

　　Before cooling and solidification of the solder, the welding part must be reliably fixed, not allowed to swing and shake, the solder joint should be cooled naturally, if necessary, heat dissipation measures can be used to speed up cooling.