Dai Fulong（戴福隆）, Shi Ling(石〓玲),Wen Xiumei(温 秀梅)

Abstract The three\|dimensional displacements fi e lds in a surface mounted plastic\|quad\|flat\|pack (PQFP) assembly are measured du ring power cycling using a combination of holographic interferometry and high se n sitivity moire interferometry. Detailed in\|plane and out\|of\|plane whole\|fiel d displacement data of the top and bottom ends of the gull wing leads and their distributions along the edge of PQFP are provided. The maximum deformations of t he gull wing leads occur at the four corners of the PQFP. The experimental resul ts are used as displacement boundary condition in a linear\|elastic analysis of the thermal stresses of the corner lead and its solder joint using a 3\|D finite element method (FEM). The highest stresses occur in the area connecting the le ad and the solder joint. The results should be useful in the evaluation of therm al fatigue damage of surface mount assemblies.