Patent ID: 7063799

Claim:
A method for manufacturing an ink jet recording head, wherein the ink jet recording head includes a supply port for receiving liquid from outside, ejection outlets for ejecting the liquid, liquid flow paths, in fluid communication with the ejection outlets, for directing the liquid supplied from the supply port to the ejection outlets, ejection pressure generating portions for generating pressure for ejecting the liquid, the generating portions being disposed at a part of the liquid flow paths, and wherein the supply port is formed as a through-opening in a substrate of Si on which ejection pressure generation elements arranged in a plurality of arrays and constituting the ejection pressure generating portion portions are formed, wherein said supply port is disposed between the arrays, said method comprising: a step of forming a recessed portion by recessing a side of the substrate of Si having the ejection pressure generation elements from a portion where the supply port is formed to a neighborhood of a portion where the ejection pressure generation elements are formed; a step of coating a surface of the recessed portion at least where the ejection pressure generation elements are formed, with a protection layer having an anti-corrosion property effective against wet etching used for forming the supply port; and a step of forming, by wet etching, the supply port in such a manner that the supply port is connected to the recessed portion where the protection layer is formed.