Patent ID: 8191260

Claim:
A manufacturing method of a liquid ejection head including an ejection outlet forming member provided with an ejection outlet for ejecting liquid and including a flow passage communicating with the ejection outlet, said manufacturing method comprising: preparing a substrate on which i) a first flow passage wall forming member having a shape defining a part of a wall of the flow passage and ii) a solid layer having a shape of a part of the flow passage contact each other, wherein the first flow passage wall forming member has a height, from a surface of the substrate, substantially equal to that of the solid layer; providing a first layer formed of a negative photosensitive resin material; exposing to light a portion of the first layer to form the ejection outlet forming member; providing a second layer, on the first layer, formed of a negative photosensitive resin material; exposing to light a portion of the second layer to form a second flow passage wall forming member for forming another part of the wall of the flow passage; placing the exposed first layer and the exposed second layer on the solid layer and the first flow passage wall forming member so that a non-exposed portion of the second layer contacts the solid layer; forming the other part of the flow passage and the ejection outlet by removing a non-exposed portion of the first layer and the non-exposed portion of the second layer above the substrate; and forming a remainder of the flow passage by removing the solid layer.