CATALYTIC SOLUTION FOR ELECTROLESS PLATING SELECTIVE TO COPPER-BASED MATERIAL

• Main Authors: HAGA MASAKI, OKADA TAKASHI, UCHIDA HIROKO, UCHIDA MAMORU
• Format: Patent
• Language: English
• Published: 13.01.1995
• Edition: 6
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; METALLURGY; PRINTED CIRCUITS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

PURPOSE:To subject only a Cu-based material in electronic parts to selective electroless plating with a metal by treating the electronic parts with a catalytic soln. for electroless plating contg. a Pd compd. and halide or sulfate of an alkali metal or an alkaline earth metal. CONSTITUTION:A printed board composed of an insulator and a Cu-based conductor is immersed in a catalytic aq. soln. contg. 0.0001-0.5mol/l Pd compd. such as (NH4)2(PdCl6) and 0.1-10mol/l at least one of halides or sulfates of alkali metals such as Na and K or alkaline earth metals such as Ca and Mg to activate the Cu-based conductor and then the printed board is immersed in an electroless plating bath such as an Ni, Pd or Pd-Ni plating bath. A plating layer of Ni, Pd, Pd-Ni, etc., is stably and selectively formed by electroless plating only on the Cu-based conductor of the printed board without causing bridging or skipping phenomenon.