A comparative study of silver-epoxy and tin-lead solder in their joints with copper, through mechanical and electrical measurements during debonding

A comparative study of silver-epoxy and tin-lead solder in their joints wit h copper was made through simultaneous mechanical and electrical measuremen ts during debonding. Silver-epoxy joints to copper abruptly increased in co ntact electrical resistivity upon completion of shear debonding, whereas ti n-lead soldered joints to copper did not, due to the higher ductility of so lder compared to silver-epoxy. The contact resistivity before debonding was higher for silver-epoxy than solder. Cleansing of the copper surface was e ssential for silver-epoxy, but not for solder. Acetone washing of copper su rface helped silver-epoxy joints, but not soldered joints. Acid washing hel ped soldered joints more than acetone washing, but helped silver-epoxy join ts to the same extent as acetone washing. (C) 1999 Kluwer Academic Publishe rs.