Multi points temperature measurement of infrared scanning method on surface mount technology

The solder joints model structure of SMT has been established. The general rules of three different positions(the shallow surface, the internal and the interface of solder and pad)were discussed. Then, the finite model has been checked by the combination of experiment and simulation. Finally, through the multi points scanning method, the heat source was applied to heat the solder joints, the temperature differences of the fixed points and no defect solder joints were contrasted, then the location and size of defects can be determined.