PREDICTING THE STRENGTH OF SOLDER JOINTS USING COHESIVE ZONE MODELING
Authors: Siva P. V. Nadimpalli and Jan K. Spelt Company: Department of Mechanical and Industrial Engineering - University of Toronto Date Published: 5/22/2009
ICSR (Soldering and Reliability)
Abstract: The fracture of a lead-free solder joint (96.5Sn3.0Ag0.5Cu and copper) under mode I loading conditions was simulated using a cohesive zone model (CZM) implemented in ANSYS® finite element software. The CZM parameters were determined using mode I fracture data from experiments with double cantilever beam (DCB) solder joint specimens. These CZM parameters, along with the mechanical properties of the solder and the copper, were then used in the finite element simulations to predict the failure loads of solder joints in two configurations: (i) DCB joints and (ii) linear arrays of discrete 1-2 mm solder joints having various pitches. The latter specimens permitted an investigation of the parameters affecting load sharing among discrete joints such as those found in ball grid arrays. The model predictions were in good agreement with the experiments.