Optimization of stiffness for isotropic conductive adhesives

With the rapid developments of electronic packaging, there is an increasing demand on high performance isotropic conductive adhesives (ICAs). However, the traditional ICAs are brittle, sensitive for crack formation and delamination, which is one of the major drawbacks that limits their use in a wide range of applications. Therefore great efforts have been made to make conductive adhesives more flexible. The present work aims at studying of several chemicals in terms of flexibilizing materials to modify the stiffness modulus of the conductive adhesives. The effect of the flexibilizers has been characterized by different methods, such as Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), Thermogravimetric Analysis (TGA), etc. Moreover, the electrical resistance, thermal conductivity and viscosity are also measured in various conditions. Experimental results indicate that one of the flexibilizing materials using flexible ester-linkage is particular of interest as it offers low electrical resistance, high thermal performance and low modulus without decreasing glass transition temperature (Tg) and influencing curing and decomposition conditions.