Photosensitive resin composition, and film and printed circuit board using same

A film comprising:

• at least one release film;
• and
• a resin layer, at least one surface of the resin layer is attached to one surface of the at least one release film, the resin layer is made by a photosensitive resin composition, the photosensitive resin composition comprising:
• a carboxylic acid-modified bisphenol epoxy (meth)acrylate;
• a photosensitive monomer;
• a photosensitive prepolymer;
• a photo-initiator;
• and
• a coloring agent;
• wherein each of the carboxylic acid-modified bisphenol epoxy (meth)acrylate, photosensitive monomer and photosensitive prepolymer has carbon-carbon double bonds, a ratio of the number of the carbon-carbon double bonds in the carboxylic acid-modified bisphenol epoxy (meth)acrylate and the number of the carbon-carbon double bonds in the photosensitive monomer is substantially between 1:20 and 1:50, the carboxylic acid-modified bisphenol epoxy (meth)acrylate has a molar mass of about 15000 g/mol to about 35000 g/mol, the carboxylic acid-modified bisphenol epoxy (meth)acrylate has an acid value of about 70 mgKOH/g to about 130 mgKOH/g;
• and
• wherein the carboxylic acid-modified bisphenol epoxy (meth)acrylate, photosensitive monomer and photosensitive prepolymer polymerize to form a dense cross-linking network structure when the photosensitive resin composition is exposed to ultraviolet radiation.

A printed circuit board comprising:

• a circuit substrate;
• and
• an insulating layer attached to at least one surface of the circuit substrate, the insulating layer is made by sticking a resin layer to at least one surface of the circuit substrate, and exposing the resin layer to ultraviolet radiation, the resin layer is made by a photosensitive resin composition, the photosensitive resin composition comprising:
• a carboxylic acid-modified bisphenol epoxy (meth)acrylate;
• a photosensitive monomer;
• a photosensitive prepolymer;
• a photo-initiator;
• and
• a coloring agent;
• wherein each of the carboxylic acid-modified bisphenol epoxy (meth)acrylate, photosensitive monomer and photosensitive prepolymer has carbon-carbon double bonds, a ratio of the number of the carbon-carbon double bonds in the carboxylic acid-modified bisphenol epoxy (meth)acrylate and the number of the carbon-carbon double bonds in the photosensitive monomer is substantially between 1:20 and 1:50, the carboxylic acid-modified bisphenol epoxy (meth)acrylate has a molar mass of about 15000 g/mol to about 35000 g/mol, the carboxylic acid-modified bisphenol epoxy (meth)acrylate has an acid value of about 70 mgKOH/g to about 130 mgKOH/g;
• and
• wherein the carboxylic acid-modified bisphenol epoxy (meth)acrylate, photosensitive monomer and photosensitive prepolymer polymerize to form a dense cross-linking network structure when the photosensitive resin composition is exposed to ultraviolet radiation.