chemical surface preparation

Michael Carano
RBP Chemical Technology

Article summary

The photoimaging process is one of the first steps in the PCB fabrication process. In order to insure that the image of the circuitry conforms as close to the desired design as possible (i.e. lines and spaces), surface preparation of the copper foil surface is one of the critical success factors. Employing the optimum mix of surface cleaners and microetchants will provide a clean surface with sufficient surface area to promote dry film adhesion. The fabricator has numerous options and should determine the optimum process by accounting for the type of copper foil used as well as the classes of soils to be removed.

Introduction

There are several options available. In addition to pumice and aluminum oxide surface preparation, chemical cleaning as a means to insure optimum photoresist adhesion has gained significant popularity. In this ca