It has been used for post weld appearance defect detection in resistance welding, hot press welding, soldering iron welding, laser melting soldering, metal welding, spray soldering, wave soldering, etc. The types of defects detected include: virtual soldering, over soldering, un soldering, solder deviation, solder bead, wireless, no solder pad, broken wire, excess wire, explosion point, continuous soldering, insufficient soldering, etc.