Patent ID: 8162448

Claim:
A liquid ejection head comprising: a flow channel-forming substrate having a plurality of pressure-generating chambers communicated with nozzles configured to eject droplets, the plurality of pressure-generating chambers being arranged in parallel with each other; a plurality of pressure-applying units configured to apply pressure to interiors of the pressure-generating chambers; and a joining substrate joined onto one surface of the flow channel-forming substrate, wherein the flow channel-forming substrate includes a silicon single crystal substrate having a ( 110 ) plane orientation and has a side surface extending in a longitudinal direction of the pressure-generating chambers, the side surface being composed of a first ( 111 ) plane perpendicular to a ( 110 ) plane, and the joining substrate includes a silicon single crystal substrate having a ( 110 ) plane orientation and is joined onto the flow channel-forming substrate so that a first ( 111 ) plane of the joining substrate perpendicular to the ( 110 ) plane intersects the first ( 111 ) plane of the flow channel-forming substrate, wherein the first ( 111 ) plane of the joining substrate is orthogonal to the first ( 111 ) plane of the flow channel-forming substrate.