Patent ID: 10363746

Abstract:
A method for producing a liquid ejection head includes a step of providing a positive photosensitive resin layer on a substrate, a step of heat-treating the positive photosensitive resin layer on the substrate, and a step of forming a mold material having a pattern of the flow path by subjecting the heat-treated positive photosensitive resin layer on the substrate to exposure and development. In the method, the positive photosensitive resin layer includes a light absorbing agent that is nonvolatile at a temperature of the heat treatment of the positive photosensitive resin layer, the light absorbing agent has a light absorbance (a1) at a wavelength of 365 nm and an average light absorbance (a2) in a wavelength range of 280 nm or more to 330 nm or less, and an absorbance ratio A is 1.0 or less where the absorbance ratio A is the ratio a2/a1.