Study of an environment-friendly surface pretreatment of ABS-polycarbonate surface for adhesion improvement

In this paper, an environmentally friendly etching system containing MnO2–H3PO4–H2SO4 colloid was used to investigate surface etching for ABS- polycarbonate (PC/ABS) as a replacement for conventional chromic acid etching solutions. In order to obtain a good etching performance, a swelling system, containing tetramethylammonium hydroxide (TMAH), and 1-Methyl-2-pyrrolidinone (NMP), was used to investigate the surface swelling for PC/ABS resin. Then the effects of H2SO4 concentration, and etching time on the surface topographies and surface contact angle were investigated. After the optimal swelling and etching treatment, the surface contact angle of PC/ABS resin decreased from 95.7° to 28.3°, and the adhesion strength between electroless copper film and PC/ABS resin reached to 1.04 KN m−1. The FT-IR spectra and XPS analyses indicated that hydroxyl and carboxyl groups formed on the PC/ABS surface as a result of the swelling and etching treatment, which improved the adhesion strength between PC/ABS substrate and elctroless copper film.