Abstract: A photosensitive resin composition used for forming an insulating layer includes a resin including an aromatic polyester imide structure, a photopolymerization initiator and a thermal radical polymerization initiator, and when the resin including an aromatic polyester imide structure does not include a (meth)acryl group, the resin composition includes a (meth)acryloyl compound.

Abstract: The present disclosure relates to a method for selecting a photosensitive resin composition, the method including: exposing a resin film of a photosensitive resin composition at 100 to 2000 mJ/cm2 and heat-treating the resin film at 150° C. to 250° C. for 1 to 3 hours under nitrogen to produce a strip sample of a cured film having a film thickness of 10 ?m and a width of 10 mm; performing a fatigue test of repeatedly pulling the strip sample under condition (1) in which the set temperature is 25° C., the distance between chucks is 20 mm, the testing rate is 5 mm/min, and the cyclic load stress is 100 MPa, or under condition (2) in which the set temperature is ?55° C., the distance between chucks is 20 mm, the testing rate is 5 mm/min, and the cyclic load stress is 120 MPa; and selecting a photosensitive resin composition satisfying the following condition: the number of times of pulling required until the strip sample breaks in the fatigue test is 100 or more cycles.