Patent ID: 7239070

Claim:
A liquid-jet head, comprising: a passage-forming substrate in which pressure generating chambers communicating with nozzle orifices are formed; piezoelectric elements provided on one surface side of the passage-forming substrate, and each comprising a lower electrode, a piezoelectric layer, and an upper electrode; and a lead-out electrode at least including a first lead electrode drawn from each of the piezoelectric elements, and wherein the lower electrode, which is a common electrode common to the plurality of piezoelectric elements, is continuously formed as far as a region outside a region opposite the piezoelectric elements, an auxiliary electrode layer is provided which comprises layers identical with layers constituting the lead-out electrode, and which is electrically connected to the lower electrode located outwardly of the region opposite the piezoelectric elements, a first insulation film covering the piezoelectric elements extends to a region where the auxiliary electrode layer is formed, in the first insulation film at least in a vicinity of an end portion of the passage-forming substrate in a direction parallel to the arrangement of the piezoelectric elements, a penetrated portion is provided in a region opposite the auxiliary electrode layer, and the auxiliary electrode layer is in contact with the lower electrode via the penetrated portion provided in the first insulation film.