Negative photosensitive material, photosensitive board employing the negative photosensitive material, and negative pattern forming method

Abstract

A negative photosensitive material is provided which has a lower linear expansion coefficient and a lower hygroscopic expansion coefficient and is excellent in gradational patternability and PI etchability in patterning. The negative photosensitive material comprises: (A) a polyimide precursor having a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2), the structural unit represented by the general formula (2) being present in the polyimide precursor in a proportion of less than 30 mol % based on the overall amount of the polyimide precursor; and (B) at least one of a pyridine derivative represented by the following general formula (3) and a pyridine derivative represented by the following general formula (4): wherein R1, R2, R3, R4 and R5, which may be the same or different, are each a C1 to C4 alkyl group, and Ar is an aryl group having a nitro group at its ortho position, wherein R1, R2, R4 and R5, which may be the same or different, are each a C1 to C4 alkyl group, and Ar is an aryl group having a nitro group at its ortho position.

Dependencies are inferred from the claim text.