Reliability of Surface‐mounted Anisotropically Conductive Adhesive Joints

Abstract

The purpose of the work is to investigate the feasibility of using anisotropically conductive adhesives to join surface‐mount devices as solder replacement. The results from a literature and market survey are reported. Based on industrial demands, two anisotropically conductive adhesives were chosen for the experimental work. During the experimental work, the conductive adhesive joints were produced at various curing conditions. The joints were characterised by shear testing and electrical resistance measurement after ageing at 20, 70 and 120°C to 1000 hours. Optical and scanning electron microscopy were used to characterise the adhesive joints. In addition to this, temperature cycling tests, humidity test and pull tensile tests were used to qualify the adhesive joint reliability and quality. From the results of the present work, it can be concluded that the anisotropically conductive adhesive A joints are stable in the 85°C/85% RH environment and therefore have better corrosion resistance than adhesive B joints. Neither of the adhesives can pass temperature cycling from −55 to 125°C for 1000 cycles according to military standard 883C.