Effects of lead-free solder on the tensile strength of QFP micro-joints soldered with different pitchs

The tensile strength of QFP was tested by micro-joint tester and the effects of pitch numbers,solder paste composition on the mechanical properties of QFP soldened joint were studied in this paper.The fracture micrograph of joint was also analyzed by means of SEM and the results indicate that for the same pitch numbers,the tensile strength of the QFP soldered joint with SnAgCu solder paste is larger than that with SnPb solder paste.With the same solder paste composition, the tensile strength of the QFP soldered joint with 48 pitchs is lower than that with 100 pitchs.