Failure patterns of solder joints identified through lifetime vibration tests

A method for non-destructively tracking the integrity of flip chip solder joints through life is investigated in this paper. An industry standard double-sided PCB was designed and manufactured with 14 chips to assess failure patterns each joint lifetime vibration tests. Two configurations finish were tested, Electro Nickel Immersion Gold (ENIG) Hot Air Surface Levelled lead (Pb HASL) using automotive manufacturing processes quality standards. random test over a frequency range 10 Hz 1000 specified by engineers replicate vibrations typically found on road vehicles. This profile applied circuit board assemblies (CBA) 4-minute intervals until all chips. At interval boards extensively scanned an acoustic micro-imaging (AMI) microscope measure parameters joints. enabled mechanical connection through-life. Methods developed process large number images form metrics evaluate integrity. Results from AMI show that exhibit three distinct zones as they age: crack initiation, propagation then failure.