Liquid ejection head

A liquid ejection head provided with a recording element substrate, the recording element substrate comprising:

• an ejection port member including an ejection port that ejects liquid;
• an electric wiring layer including a pressure generating element array and electric connection portions, the pressure generating element array including arranged pressure generating elements each pressurizing the liquid for ejection of the liquid, and the electric connection portions being connected to the respective pressure generating elements through electric wirings and supplying power for driving the pressure generating elements to the respective pressure generating elements;
• and
• a silicon substrate including the ejection port member and the electric wiring layer on a front surface,
• wherein the silicon substrate includes a first through hole and a second through hole that penetrate through the silicon substrate, protrude the electric connection portions, and correspond to one line of the pressure generating element array,
• wherein an opening of the first through hole and an opening of the second through hole are made on a rear surface of the silicon substrate, and the opening of the second through hole is located closest to the opening of the first through hole in a [110] direction of the silicon substrate,
• wherein the rear surface of the silicon substrate is a (100) surface, and
• wherein an extension line of a side extending along the [110] direction, out of sides of the opening of the first trough hole and an extension line of a side extending along the [110] direction, out of sides of the opening of the second through hole are displaced from each other in a direction orthogonal to the [110] direction.