Patent ID: 8703398

Claim:
A method of manufacturing a liquid ejection head, the liquid ejection head comprising: a substrate including, at a first surface side thereof, a plurality of ejection energy generating elements for generating energy for ejecting liquid droplets; and a flow path forming member provided at the first surface side of the substrate, the flow path forming member forming a plurality of ejection orifices for ejecting the liquid droplets, the plurality of ejection energy generating elements being arranged in at least one row at the first surface side of the substrate, the plurality of ejection orifices being formed at positions corresponding to the plurality of ejection energy generating elements, respectively, the plurality of ejection orifices each having a tapered shape in which a cross-sectional area thereof decreases from an inner opening toward an outer opening, the method comprising, in the following order: (1) disposing a negative resist on or above the substrate to form a negative photosensitive resin layer; (2) forming, on or above a surface of the negative photosensitive resin layer, a hollow having inclinations at both sides in a cross section taken along a plane perpendicular to a row direction of the plurality of ejection orifices, the hollow being formed along a row direction of the plurality of ejection energy generating elements at a position on the surface of the negative photosensitive resin layer so as to extend over the plurality of ejection orifices, the position corresponding to a row of the plurality of ejection energy generating elements; (3) performing exposure treatment to form a latent image of each of the plurality of ejection orifices in the hollow, the latent image being formed of an unexposed portion; and (4) performing development treatment to remove the unexposed portion, to thereby form the plurality of ejection orifices, wherein the latent image has a front surface portion disposed in the hollow so that an end portion of the front surface portion of the latent image is positioned in the inclinations at the both sides, and wherein an angle between a side surface portion of the latent image and a normal to the front surface portion in a cross section of the latent image taken along a plane which passes through a center of the latent image and is perpendicular to the row direction of the plurality of ejection orifices is larger than an angle between the side surface portion and the normal to the front surface portion in a cross section of the latent image taken along a plane which includes a center line of the latent image in the row direction of the plurality of ejection orifices and is perpendicular to a substrate surface.