Abstract：Popcorn delamination failure of plastic electronic packages made of thermohyperelastic material featuring Gent-Thomas, during the solder-reflow process, resulted from the integrated effects of vapor pressure induced by the moisture and thermal stress induced by heat mismatch was studied.Using the theory of cavity formation and unstable void growth in incompressible hyper-elastic material, we gained an analytical relationship between void growth and the sum of the vapor pressure and thermal stress. Numerical analysis shows that popcorn failure won’t occur when the moisture in voids is in single vapor phase during the solder-reflow process on condition that plastic electronic packages absorb little moisture; plastic electronic packages produce popcorn failure when the vapor pressure maintains saturation state during the solder-reflow process on condition that plastic electronic packages absorb sufficient moisture.
2011, Vol. 32 
