The influence of adhesive composition on mechanical and electrical properties of joints between SMDs and PCBs

The main goal of this paper is to establish how conductive adhesive composition will influence the electrical and mechanical properties of joints between SMDs and PCBs. Eight conductive adhesive compositions were investigated. The design of experiments methodology based on Taguchi orthogonal array was applied to compose the best adhesive properties for SMT. Two types of polymer matrix were applied. Two controllable factors for defining the compositions were used: type of filler material and level of volume contents of filler in adhesive. The filler materials and conductive adhesive compositions were prepared by AMEPOX Microelectronics, Poland. The individual adhesive joint resistance of 1206 jumper and adhesion of 1206 jumper to PCB were used as the measure of adhesive joint quality. It was found that the biggest influence on mechanical and electrical properties are the type of isolating resin and the type of filler material. For such compound adhesives the average individual joint resistance changed from 30 to 173 mn and average shearing force for 1206 component from 3 to 40 N.