Liquid ejection head, liquid ejection module, and method of manufacturing liquid ejection head

A liquid ejection head comprising:

• a substrate including a pressure generating element configured to apply pressure to a first liquid;
• a member provided with an ejection port configured to eject a second liquid;
• a pressure chamber including the ejection port and the pressure generating element;
• and
• a liquid flow passage formed by using the substrate and the member stacked on the substrate, the liquid flow passage including the pressure chamber and extending in a direction of flow of at least the first liquid and the second liquid, wherein
• the substrate includes
• a first inflow port located on an upstream side of the pressure chamber in the direction of flow of the liquids in the liquid flow passage and configured to allow the first liquid to flow into the liquid flow passage,
• a second inflow port located on the upstream side of the first inflow port and configured to allow the second liquid to flow into the liquid flow passage, and
• a lateral wall extending in a direction of extension of the liquid flow passage, at least part of the lateral wall being located above the first inflow port, and
• in the pressure chamber, the first liquid flows in contact with the pressure generating element and the second liquid flows closer to the ejection port than the first liquid does.