Study on surfce mount technology for fine pitch L type lead devices

摘要

Problems about surface mounting process for fine pitch devices and reasons on solder bridging of L type leaddevices welded are depicted. Bridging mechanism and influence factors are analyzed with two-dimensional geometricmodel.Based on this,high-density surface mount technology(SMT) for fine pitch L type lead devices heated by scan-ning laser is raised. Surface mount process for QFP208 on printed circuit board(PCB)is studied.The results of testsare that it is quite possible to solve the solder bridging of surface mounting for pitch devices with scanning laser-heat-ing method.