IMAGE-REVERSIBLE DRY-FILM PHOTORESISTS

摘要

A dry-film photoresist is described which comprises a film of a light-sensitive image-reversible photoresist composition supported on a removable backing sheet and, optionally, having a removable cover sheet extending substantially completely over the exposed surface of the film. The photoresist composition employed in the film comprises a mixture of at least one phenolic resin, a 1,2-quinonediazide sensitizer and, optionally, at least one organic solubilizing agent containing phenolic and/or carboxylic acid groups and present in the mixture in an amount to promote the solubility of the mixture in alkaline developer. The dry-film photoresist can be used to produce either positive or negative resists on a substrate. The dry-film photoresist is laminated to the substrate and then exposed imagewise to actinic radiation. To produce a positive image the exposed film is developed using an alkaline developer. To produce a negative image the exposed film is first baked to a temperature and for a time sufficient to render the exposed portions of the photoresist insoluble in alkaline developer and is then developed, optionally after flood exposure to actinic radiation, using an alkaline developer to remove the unwanted portions of the photoresist.