A New Method Using Energy Release Elements to Estimate the Bonding Strength

Abstract

We developed a method for estimating the bonding strength of bonded areas of various sizes. We compared the debonding forces estimated by the stress-singularity-parameters approach (SSPA) with those measured by a shear debonding test of photoresist patterns on Cu substrates. This comparison showed that SSPA cannot be used to estimate the bonding strength of bonded areas of a wide range of sizes. We therefore developed a new method (based on the energy release rate) for estimating the bonding strength. This method uses a finite element approach and places “energy release elements (EREs)” (which mathematically represent the energy release due to debonding) between the two materials. The characteristics of EREs are represented by two parameters determined by two experimental measurements. We used this method to estimate the shear debonding strength of photoresist patterns on Cu substrates and found that the estimated values for the debonding strength agree well with the measured results.