Method for imparting water repellency to surface of member

A method for imparting water repellency to an ejection port surface of a liquid ejection head, the ejection port surface being a surface of the liquid ejection head on which an ejection port is formed, the method comprising:

• a step in which a material including a compound containing a fluorine atom is deposited on a surface of a photosensitive resin layer on a substrate, the surface of the photosensitive resin layer serving as an ejection port surface, in order to form a member including the photosensitive resin layer and a material layer including the material, the material layer being disposed on a front surface of the photosensitive resin layer;
• a first exposure step in which a surface of the member is exposed to an amount of light with an exposure apparatus in order to form a latent image in the photosensitive resin layer and the material layer of the member;
• a development step in which the member including the latent image is developed, thereby removing the photosensitive resin layer and the material layer within the latent image, the ejection port being formed at a portion where the member has been removed;
• an initial curing step in which the member is initially cured after the development step, wherein, in the initial curing step, the member is heated at 120° C. or more and 160° C. or less for 2 minutes or more and 4 minutes or less;
• a second exposure step in which the surface of the member is exposed to an amount of light with an exposure apparatus subsequent to the development step and the initial curing step, wherein exposure in the second exposure step is incident from the same side as the first exposure and imparts water repellency to the member and thereby increasing a contact angle of pure water on the surface of the member by 3° or more;
• a supply port forming step in which a supply port is formed by etching the substrate after the second exposure step;
• an ultraviolet light irradiation step in which the member is irradiated with ultraviolet light after the supply port forming step;
• a member removal step in which a part of the member is removed after the ultraviolet light irradiation step;
• and
• a final heat curing step in which the member is cured after the member removal step, and in which the member is heated at 170° C. or more and 220° C. or less for 30 minutes or more and 120 minutes or less.