Aluminum Resistance Spot Welding and its Welding Quality System Resistance spot welding (RSW) is a method of assembling a welding piece into a lap joint and pressing it between two electrodes, and using resistance heat to melt the base metal to form a solder joint. Compared with riveting or other welding methods, spot welding has the advantages of high joint quality, fewer auxiliary processes, high production efficiency, no need to add welding materials, and easy to realize mechanization and automated production. It is widely used in automotive, aerospace, and electronic technology industries. In early phase of testing the quality of solder joints is to evaluate through destructive testing, to test the tensile strength of the sample solder joints and to measure the nugget diameters.