US Patent 7571991 Liquid ejection head and manufacturing method thereof

The liquid ejection head includes: a first SOI substrate which has a first active layer, a first dielectric layer and a first supporting layer; a second SOI substrate which has a second active layer, a second dielectric layer and a second supporting layer, the second active layer being bonded to the first supporting layer; and a nozzle which is formed between the first supporting layer and the second dielectric layer, the nozzle ejecting liquid in an ejection direction perpendicular to a thickness direction of the first SOI substrate and the second SOI substrate, a cross-sectional width of the nozzle perpendicular to the ejection direction being defined by a thickness of the second active layer.