Patent attributes
There is provided a first die, in which a plurality of projections are arrayed in a first direction with a fixed pitch to form at least one array of the projections. Each of the projections is elongated in a second direction perpendicular to the first direction. The first die faces a first face of the plate member. A second die is opposed to the first die while supporting a second face of the plate member. At least one first region is formed on the plate member so as to have a less rigidity than another region of the plate member. The first die and the second die are approached so that the projections are dug into a second region in the first face of the plate member, thereby forming partitioned recesses to be pressure generating chambers of a liquid ejection head. The at least one first region is adjacent to at least one of ends in the first direction of the second region, such that the first region and the second region are arranged in the second direction.