What is the classification of photoresists


1. Photopolymerization type
Using olefinic monomers, free radicals are generated under the action of light, which further initiate monomer polymerization and ultimately generate polymers, with the characteristic of forming positive images.
2. Photodecomposition type
Using materials containing azide quinone compounds, after exposure to light, a photodegradation reaction occurs, changing from oil soluble to water soluble, and can be made into a positive adhesive.
3. Photocrosslinking type
Polyvinyl alcohol laurate and other photosensitive materials are used. Under the action of light, the double bonds in its molecules are opened, and the chains are crosslinked to form an insoluble network structure, which plays a role in corrosion resistance. This is a typical negative photoresist. Kodak's product KPR adhesive belongs to this category.