Method of manufacturing liquid ejection head

A method of manufacturing a liquid ejection head, the liquid ejection head comprising:

• a substrate having an ejection energy generating element for generating energy for ejecting a liquid formed therein;
• and
• a nozzle layer having an ejection orifice and a liquid flow path formed therein, the ejection orifice being provided for ejecting the liquid, the liquid flow path communicating to the ejection orifice and being provided for placing the liquid above the ejection energy generating element,
• the method comprising:
• (1) forming a metal layer consisting of a first metal on the substrate having the ejection energy generating element formed therein;
• (2) forming a liquid flow path pattern consisting of a second metal that is dissolvable in a solution that does not dissolve the first metal, the liquid flow path pattern being formed on at least a part of a surface of the metal layer;
• (3) forming a material layer to be formed as the nozzle layer of multiple layers and covering the liquid flow path pattern with one of the multiple layers, the one of the multiple layers that covers the liquid flow path pattern consisting of a third metal that is not dissolvable in the solution;
• (4) forming the ejection orifice in the material layer;
• and
• (5) dissolving the liquid flow path pattern in the solution to remove the liquid flow path pattern, to thereby form the liquid flow path,
• wherein the first metal and the second metal are metals of different kinds,
• wherein a standard electrode potential E1 of the first metal and a standard electrode potential E2 of the second metal have a relationship of “E1>E2”,
• wherein the second metal and the third metal are metals of different kinds, and
• wherein a standard electrode potential E3 of the third metal is such that “E2<E3”.