PURPOSE: To obtain a lead frame for piezoelectric components which is superior in resistance to wear or abrasion by plating base materials with either Ni, Co or an alloy thereof and after that, plating the above materials with Ag or an Ag alloy and immersing the plate materials in a solution containing either higher aliphatic amine, mercaptan or a mixture thereof.

CONSTITUTION: Base material consisting of a Cu-covering steel material and the like is plated with Ni, Co or an alloy thereof in the thickness of 0.01μm or thicker by the use of Watts bath, sulfamic acid bath, and chloride bath and then, the plated base material acts as a barrier to diffusion of a base material component. Subsequently, plating of Ag or an Ag alloy is performed by the use of cyanogen bath, nitric acid bath, thiocyanic acid bath, and iodide bath. After that, the base material immersed in a solution containing 0.05-5% of either higher aliphatic amine, i.e., dodecylamine and the like, higher aliphatic mercaptan and the like, i.e., dodecylmercaptan and the like or a mixture thereof, in this way, resistance to wear or abrasion of the materials is improved. Then this coating treatment decreases the coefficient of friction without increasing contact resistance.