Abstract

Two different systems of light-sensitive resist materials precoated on carrier foils and their potential applications for thickfilm-technology and high quality printed circuits are described. In addition to 25 μm diazo screen printing film already accepted in this field, new experimental films up to 70 μm thickness can be provided. They show excellent shelf-life and can be transferred to the screen and developed after exposure simply with water. The second system is a 12 μm positive dry film resist based on the same chemistry as all positive liquid resists. After lamination to a substrate it can be exposed directly on the resist. It gives better resolution than negative dry film resists and offers a potential for multiple exposure. Thicker positive dry films are possible using a new positive system without diazo compounds.