The invention addresses the problem of improving the adhesion between silver surfaces and resin materials, such as epoxy resins and mold materials, used in the production of electronic devices. The invention provides a method for improving the adhesion between a silver surface and a resin material comprising a step of electrolytically treating the silver surface with a solution containing a hydroxide selected from alkali metal hydroxides, alkaline earth metal hydroxides, ammonium hydroxides and mixtures thereof, wherein the silver surface is the cathode. In a particular embodiment of this method, the present invention provides a method for producing a surface mounted electronic device comprising the following steps: (i) providing a lead frame having copper and silver surfaces, (ii) electrolytically treating the silver surfaces of the lead frame with a solution containing a hydroxide selected from alkali metal hydroxides, alkaline earth metal hydroxides, ammonium hydroxides and mixtures thereof, wherein the lead frame is the cathode, (iii) encapsulating an electronic device together with the lead frame using a resin material.