ADHESION STRENGTH OF SILVER THICK-FILM CONDUCTORS BY SOLDER-FREE TEST

Adhesion of silver thick-film conductors to alumina substrates was stu died by a solderless testing meth od, in wh ich al um ina substrates w ere bonded with a silver thick-fi Im and pul led vertically under a co nstant strain rate to fracture. The fracture behaviour was studied on thick films prepared under different conditions, and the effect of mic rostructure on the adhesion strength was studied. A new parameter has been introduced for evaluating the resistance to crack propagation. He nce, microstructural requirements for high adhesion strength thick fil ms have been proposed. The adhesion strength data of silver thick film s have been best described by a log-normal distribution function.