Liquid ejection head and method of manufacturing the same

A liquid injection head comprising:

• a substrate including:
• energy generating elements configured to apply energy for ejection to a liquid;
• and
• a substrate upper surface on which terminals respectively connected to electric wirings are provided;
• an ejection port forming member having:
• an ejection port forming surface in which ejection ports for ejecting a liquid are formed, and having an end region which includes at least one cutout;
• and
• a back surface on a side opposite to the ejection port forming surface, which is arranged so as to opposite to the substrate upper surface;
• and
• a sealant configured to cover connecting portions between the electric wirings and the terminals,
• wherein at least an ejection port region of the ejection port forming surface, in which the ejection ports are formed, is formed as a high water-repellency region,
• wherein the end region of the ejection port forming surface, which is located between the ejection port region and the terminals when the substrate upper surface is viewed in plan view, is formed as a low water-repellency region having water repellency lower than water repellency of the high water-repellency region, and
• wherein at least a part of the end region including the cutout is covered with the sealant,
• wherein, when an opening width of the cutout on the ejection port forming surface is set to 2R, a density of the sealant is set to ρ, a surface tension of the sealant is set to σ, and a gravitational acceleration is set to g, the cutout is formed so as to satisfy;
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