Material Characterization and Non-Destructive Failure Analysis by Transient Pulse Generation and IR-Thermography

IR-thermography has become increasingly important for non-destructive testing of microelectronic devices and structures on chip, package and board-level. This paper focuses on the evaluation of best applicability for different pulse excitation modes to detect flaws and damages as well as to determine material properties. Pulse IR thermography using electrical and laser excitation was chosen as an analytic method to observe and quantify crack growths in vias under thermal cycling load. We found that cracks are detectable unambiguously and its advantage over the ohmic test. The laser excitation in contrast to the electrical excitation has a good potential for large-scale screening as the board can be stepwise thermally excited and screened in one go without having any additional measuring lines. A new concept detecting crack tips was demonstrated.