Method for selective electroless plating copper onto a non-conductive substrate surface

摘要

Multistep process for electroless plating copper onto a non-conductive surface including the steps of 1) laminating a rough copper sheet onto the non-conductive surface; 2) etching away all the copper; 31 conditioning the surface with multifunctional positively charged molecules derived from copolymers of polyacrylamide and functionally active tetraalkylammonium compounds in an diluted inorganic acid; 4) activating the conditioned surface preferably with stannous palladium chloride particles; 5) treating the activated surface with deionized water and diluted HCI; 6) applying a photoresist layer to the surface and selectively exposing and developing the photoresist to produce a mask corresponding to the negative of the desired circuit pattern; and 7) plating copper using successively two baths differing in their oxygen and CN - concentration, where the foregoing steps are interspersed with washing steps.;The inventive method is particularly useful to produce copper circuit on substrates of glass, thermoplastics and thermosetting resins, like epoxy cards and boards. If the step 1) is omitted the method is also applicable in reworking substrates having already undergone copper plating and having been rejected due to failures.