Influence of PCB design and materials on chip solder joint reliability

This paper describes chip solder joint reliability on three substrate types: one board SMI (aluminium substrate) and two different boards in FR4. Several chip sizes and types (resistor, capacitor) were assembled on these boards. Accelerated Thermal cycles (ATC) -55/+125°C were applied to evaluate the lifetime of chip solder joints. The different results obtained showed an important dispersion in Time To Failure (TTF) according to the substrate type. Literature data confirm this dispersion. To understand this discrepancy Finite Element Modelling (FEM) analyses were used to evaluate the influence of PCB design and materials on solder chip component reliability. The simulations permit to identify which parameters are the most influent.