| abstract |
The present invention relates to a photosensitive resin composition excellent in flexibility, ultraviolet development sensitivity, developability in an aqueous alkaline solution, and storage stability at room temperature, and a circuit board using the same. This photosensitive resin composition is obtained by blending a siloxane-containing polyamic acid resin having structural units represented by the following formulas (1), (2) and (3) with a photopolymerization initiator. The circuit board is formed by coating the photosensitive resin composition on the substrate. In the formula, Ar represents an aromatic tetracarboxylic acid residue, R 1 is an alkyl group or phenyl group having 1 to 6 carbon atoms, R 2 is an alkylene group or phenylene group having 2 to 6 carbon atoms, and l is 0 to 10 R 3 represents a divalent group or a direct bond, R 4 represents a group represented by —CH 2 ═CH—R 6 —, R 6 is a direct bond, and has 1 to 6 carbon atoms. An alkylene group or a phenylene group is represented, R 5 represents a diamine residue, m representing the molar ratio of each constituent unit is 0.3 to 0.95, n is 0.05 to 0.7, and o is 0 to 0.5. |