Effect of temperature cycling stress profile on the thermal fatigue life of solder joints of QFP
  Revised:May 19, 2003
View Full Text  View/Add Comment  Download reader
DOI:10.7511/jslx20052035
KeyWord:temperature cycling stress profile,solder joint,visco-plastic,finite element model,thermal fatigue life
WANG Kao  CHEN Xun  CHU Wei-hua
Hits: 1308
Download times: 8
Abstract:
      This paper introduces the unified visco-plastic Anand constitutive equation to depict the visco-plastic deformation behavior of solder joints of QFP (Quad Flat Package). The finite element model of QFP mounted on printed circuit board is built by the finite element analysis software to study the influence of the temperature range, the ramp rate and the length of dwell time on stress distribution and plastic strain in 60Sn40Pb solder joint. The plastic-strainbased Coffin-Manson equation is used to predict the fatigue life of solder joints of QFP. Subsequently the effect of temperature cycling stress profile on the thermal fatigue life of solder joints is studied. The results of this study will provide valuable guidance to determine the most efficient temperature profile of the thermal cycling which is very important to thermal cycling tests.