Patent ID: 7371591

Claim:
A process for manufacturing a liquid ejection head including an energy generating element formed on a substrate for applying energy to a liquid; a liquid chamber containing the energy generating element and the liquid to be ejected; a nozzle for ejecting the liquid contained in the liquid chamber; and an electrode formed on the substrate for achieving electrical connection to the outside, the process comprising the steps of: forming a protective layer in a region of the substrate including the electrode; forming a soluble resin layer in a region including a region of the substrate where the energy generating element has been formed, for forming the liquid chamber; forming a coating resin layer in a region covering the soluble resin layer and a region above the electrode where an opening is formed in the coating resin layer; forming an opening in the coating resin layer above the energy generating element to form the nozzle; dipping the substrate in a dissolving liquid to dissolve the soluble resin layer; and removing the protective layer after dissolution of the soluble resin layer.