Novell test concept for experimental lifetime prediction of miniaturized lead-free solder contacts

Many investigations in lead-free solder-bumps on real components have been done with more or less successful lifetime prediction. Thermo-mechanical loads during temperature cycle test e.g. -40/spl deg/ to +125/spl deg/C the solder materials weaken thru time independent and time dependent plastically deformation. Solder bumps underneath real packages usually with chip on interposer are not only stressed by shear forces but also by tensile force in z-direction. The collected data may match the studied component very well, but is it possible to transfer it to other electronic packages?.