Aqueous Resist Development Considerations for Fine Feature Resist Image Formation

Dry film aqueous processable photoresists are used to define etched features in a variety of metals in the Photochemical Machining industry. Various applications place different demands on the image quality of the photoresist and not all users need optimum performance of the resist. Decorative applications may not have need for etching very narrow features and the edge quality and exact image size may not be of great concern. Others may not have a need to create very small features but they may be required to meet very tight image tolerances. Whatever the need, resist image quality will be influenced by the development process. Good resist image quality is characterized by correct image size as defined by the phototool, straight resist sidewalls and a uniform resist foot that is not negative or overly positive. Good resist image definition is needed to achieve the best etched feature quality.