Robust solder joint attachment of coaxial cable leads to piezoelectric ceramic electrodes

A technique is developed for the solder attachment of coaxial cable leads to the silver-bearing thick film electrodes on piezoelectric ceramics. Soldering the cable leads directly to the thick film causes bonds with low mechanical strength due to poor solder joint geometry. A barrier coating of 1.5-μm Cu/1.5-μm Ni/1.0-μm Sn deposited on the thick film layer improves the strength of the solder joints by eliminating the absorption of Ag from the thick film which is responsible for the improper solder joint geometry. The procedure does not require special preparation of the electrode surface and is cost-effective due to the use of non-precious metal films and the batch processing capabilities of the electron beam deposition technique