Tellerium-stabilised electroless copper plating soln. - by addition of tellurous or telluric acid or salt

摘要

A concentrate, which on dilution with HCHO, provides an electroless plating bath contains Cu+ ions a hydroxide, a complexing agent and telluric or tellurous acid or salt. Bath pref. contains 2-400 ppm. esp. 60-100 ppm of additive in the form of the acid or alkali metal or ammonium salt. Both concns. may be maintained by addition of a concentrate containing only cuprous salt, tellurium additive and opt. complexing agent e.g. EDTA. Stability of plating soln. is enhanced by Te cpd. The bath is used to plate plastics, esp. in the prodn. of printed circuits.