The present invention relates to provision of a photosensitive resin composition containing (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, and (B) a photopolymerization initiator, wherein at least one of the components contained in the photosensitive resin composition is a component including a dicyclopentadiene structure; a photosensitive resin film using the foregoing photosensitive resin composition; a printed wiring board and a method for producing the same; and a semiconductor package.

The present invention provides a surface treatment film that is capable of imparting durability such as wear resistance, friction resistance, chemical resistance, heat resistance, and solvent resistance to the surfaces of various substrates, and that exhibits excellent adhesion to the surfaces of the substrates. The surface treatment film is provided on the surface of a substrate. The surface treatment film has a laminated structure that includes a polymer layer (i) disposed on the surface side of the substrate and a polymer layer (ii) disposed on the polymer layer (i). The polymer layer (i) contains a first polymer derived from a polymerization initiation group-containing polymer, such as a polyester having, in a side chain, a functional group represented by formula (1) wherein R.sub.1 represents a hydrogen atom, a methyl group, or the like, R.sub.2 represents a methyl group or the like, X represents a chlorine atom or the like, Y represents O or NH, and * shows a bonding position. The polymer layer (ii) contains a second polymer which contains a constituent unit derived from a monomer such as an aromatic vinyl-based monomer and which extends using the functional group represented by formula (i) as a polymerization initiation point.

The present invention provides a surface treatment film that is capable of imparting durability such as wear resistance, friction resistance, chemical resistance, heat resistance, and solvent resistance to the surfaces of various substrates, and that exhibits excellent adhesion to the surfaces of the substrates. The surface treatment film is provided on the surface of a substrate. The surface treatment film has a laminated structure that includes a polymer layer (i) disposed on the surface side of the substrate and a polymer layer (ii) disposed on the polymer layer (i). The polymer layer (i) contains a first polymer derived from a polymerization initiation group-containing polymer, such as a polyester having, in a side chain, a functional group represented by formula (1) wherein R.sub.1 represents a hydrogen atom, a methyl group, or the like, R.sub.2 represents a methyl group or the like, X represents a chlorine atom or the like, Y represents O or NH, and * shows a bonding position. The polymer layer (ii) contains a second polymer which contains a constituent unit derived from a monomer such as an aromatic vinyl-based monomer and which extends using the functional group represented by formula (i) as a polymerization initiation point.