Liquid ejection head and manufacturing method for the same

A manufacturing method for a liquid ejection head, the liquid ejection head comprising:

• a substrate;
• an ejection orifice forming member having an ejection orifice configured to eject a liquid, the ejection orifice forming member being formed on a surface of the substrate;
• and
• a surface layer having a recess that has a bottom portion communicating with the ejection orifice and an opening held in contact with an outside and having a width larger than a width of the ejection orifice, the surface layer being formed on the ejection orifice forming member,
• the manufacturing method comprising:
• forming a first resin layer serving as the ejection orifice forming member by applying a negative photosensitive resin composition A onto the surface of the substrate;
• forming a second resin layer serving as the surface layer by applying a negative photosensitive resin composition B having sensitivity lower than sensitivity of the negative photosensitive resin composition A onto the first resin layer;
• subjecting the first resin layer and the second resin layer to pattern exposure collectively;
• and
• subjecting the first resin layer and the second resin layer to development treatment collectively after the pattern exposure, thereby forming the recess in the second resin layer, the recess having a side surface inclined with respect to a direction perpendicular to the surface of the substrate.