Practical Adhesion of an Ag - Pd Thick-Film Conductor: An Acoustic Emission Study of Pull Tests-Part II, Aged Adhesion

The practical adhesion strength of an aged (150°C for 48 h) Ag-Pd thick-film conductor on 96-percent alumina was investigated using an acoustic emission monitoring system and a 90° bent wire pulltest configuration. The presence of solder-metal-binder glass reactions and reaction products resulted in a decrease in adhesion strength by about 50 percent from the initial test values. The acoustic emissions recorded for the aged samples showed a large amount of low-level continuous emissions during pull testing. These emissions were distinguishable from those found on unaged parts.