Assisted Preparation of Waterborne Anti-etching Coating for Printed Circuit Board Photoresist Using Dibenzoyl Peroxide/Copper(II)-Phthalocyanine at Room Temperature

Abstract

The waterborne printed circuit board (PCB) photoresist is a photopolymer material that offers several environmental advantages over traditional solvent-borne PCB photoresists, including low pollution, low volatility, and easy cleaning, which can effectively reduce occupational health risks. This paper presents a simple stirring-resting step-reaction at room temperature and atmospheric environment to achieve the cross-linking copolymerization of waterborne acrylic resin with trimethylolpropane triacrylate (TMPTA) through the self-decomposition reaction of dibenzoyl peroxide (BPO) with copper(II)-phthalocyanine (CuPc). Subsequently, a modified resin with both thermosetting and photosetting properties was formulated to produce a waterborne eco-friendly PCB photoresist with low volatile organic compounds (VOCs). The photoresist exhibits good water solubility and can be diluted to a maximum of 12% water content while ensuring a resolution of 35 μm. Additionally, the printing performance and rheological characteristics of photoresists with different TMPTA ratios and water contents were analyzed. It was found that the photoresist exhibited the best-related performances when the ratio of acrylic resin to TMPTA was 3:7 and the water content was 9%. This formulation requires readily available raw materials, low production equipment requirements, and simple operation and is suitable for mass production.