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

A liquid ejection head substrate comprising:

• a liquid flow passage through which a liquid is capable of flowing;
• a plurality of ejection ports communicating with the liquid flow passage and capable of ejecting the liquid;
• an ejection port array in which the plurality of ejection ports are aligned;
• a plurality of energy generation elements provided to be opposed to the ejection ports and configured to generate energy for ejecting the liquid in the liquid flow passage from the ejection ports;
• and
• a substrate provided with the energy generation elements, wherein
• a flow passage wall-forming layer in which the liquid flow passage is formed is formed on the substrate,
• an ejection port-forming layer in which the ejection port array is formed is formed on the flow passage wall-forming layer, and
• the liquid ejection head substrate includes a groove that is provided in the ejection port-forming layer along the ejection port array and that has a bottom portion formed of the ejection port-forming layer or the flow passage wall-forming layer.

A manufacturing method of a liquid ejection head including a liquid flow passage through which a liquid is capable of flowing, a plurality of ejection ports communicating with the liquid flow passage and capable of ejecting the liquid, an ejection port array in which the plurality of ejection ports are aligned, a plurality of energy generation elements provided to be opposed to the ejection ports and configured to generate energy for ejecting the liquid in the liquid flow passage from the ejection ports, and a substrate provided with the energy generation elements, the manufacturing method comprising:

• forming a flow passage wall-forming layer in which the liquid flow passage is formed, on the substrate;
• forming an ejection port-forming layer in which the ejection port array is formed, on the flow passage wall-forming layer;
• and
• forming a groove having the ejection port-forming layer or the flow passage wall-forming layer as a bottom portion, in the ejection port-forming layer along the ejection port array.