Printing element substrate, liquid ejection head, and liquid ejection apparatus

A liquid ejection head, comprising:

• a printing element substrate that includes a first unit, a second unit, and a power supply wiring line including a first portion and a second portion, the first unit including a first element and a second element, the second unit including a third element and a fourth element, the first portion supplying electric power to the first unit, the second portion supplying electric power to the second unit;
• and
• a tank that stores a liquid to be supplied to the printing element substrate,
• wherein the power supply wiring line includes an extension portion that extends along a boundary line between the first unit and the second unit,
• the first element and the third element are arranged symmetrically with respect to the extension portion,
• the second element and the fourth element are arranged symmetrically with respect to the extension portion, and
• the first portion and the second portion are arranged symmetrically with respect to the extension portion.

A liquid ejection apparatus, comprising:

• a printing element substrate that includes a first unit, a second unit, and a power supply wiring line including a first portion and a second portion, the first unit including a first element and a second element, the second unit including a third element and a fourth element, the first portion supplying electric power to the first unit, the second portion supplying electric power to the second unit;
• and
• a tank that stores a liquid to be supplied to the printing element substrate;
• and
• conveying unit for conveying a print medium,
• wherein the power supply wiring line includes an extension portion that extends along a boundary line between the first unit and the second unit,
• the first element and the third element are arranged symmetrically with respect to the extension portion,
• the second element and the fourth element are arranged symmetrically with respect to the extension portion, and
• the first portion and the second portion are arranged symmetrically with respect to the extension portion.