| 摘要 |
<p>A photosensitive resin composition excellent in flexibility, ultraviolet sensitivity for development, developability with an aqueous alkali solution, and storage stability at room temperature; and a circuit substrate employing the composition. The photosensitive resin composition comprises a siloxane-containing polyamic acid resin having structural units respectively represented by the following formulae (1), (2), and (3) and a photopolymerization initiator incorporated therein. The circuit substrate comprises a base and, formed thereon, a film of the photosensitive resin composition. In the formulae, Ar represents a residue of an aromatic tetracarboxylic acid; R1 represents C1-6 alkyl or phenyl; R2 represents C2-6 alkylene or phenylene; l is a number of 0-10; R3 represents a divalent group or a direct bond; R4 represents-CH2 =CH-R6-, wherein R6 represents a direct bond, C 1-6 alkylene, or phenylene; R5 represents a diamine residue; and m, n, and o, indicating the molar proportions of the respective structural units, are 0.3-0.95, 0.05-0.7, and 0-0.5, respectively.</p> |
