US Patent 7126255 Piezoelectric/electrostrictive film-type device

A piezoelectric/electrostrictive film-type device is provided which includes a ceramic substrate having a thin diaphragm portion and a peripheral thick portion, a lower electrode, an auxiliary electrode, a piezoelectric/electrostrictive film, and an upper electrode. The lower electrode, the auxiliary electrode, the piezoelectric/electrostrictive film, and the upper electrode are layered in that order on the ceramic substrate. The upper electrode has a length of 30 to 70% relative to the length of the thin diaphragm portion, and preferably has a width of 70% or more relative to the width of the thin diaphragm portion.