Water-soluble solder paste can be cleaned with deionized water after soldering. Generally, it can be cleaned by soaking, spraying, ultrasonic, etc., and then rinsed with deionized water. Finally, the PCB drys naturally or with hot air. With the development of technology, packaging manufacturers require higher reliability of the solder joint: bright solder joints, no residue, higher electrical performance, and a more environmentally friendly process. The processes of water-soluble solder paste are the same as that of no-clean solder paste, but the operating environment of water-soluble solder paste is stricter. The stability of the water-soluble solder paste is a little worse than that of the no-clean solder paste.