| 摘要 |
A liquid sensor (60) comprising: a cavity plate (41) having a first surface and a second surface opposite to each other, the cavity plate (41) having a through hole passing therethrough; a vibration plate (42) laminated on the second surface of the cavity plate (41) so that one end of the through hole of the cavity plate (41) is closed and that a part of the vibration plate (42) and the through hole of the cavity plate define a cavity (43) opened at a side of the first surface of the cavity plate (41); a piezoelectric element including a first electrode (46) formed on the vibration plate and located opposite from the cavity plate (41), a piezoelectric layer (47) laminated on the first electrode (46), and a second electrode (49) laminated on the piezoelectric layer (47); and an exit/entrance plate (52) laminated on the first surface of the cavity plate, the exit/entrance plate (52) having a first through hole (53b) passing therethrough, and a second through hole (54b) passing therethrough and separated from the first through hole (53b), wherein: the first and second through holes (53b, 54b) of the exit/entrance plate (52) are located in an inside of a region corresponding to the part of the vibration plate (42) in a plane view; and the cavity plate (41), the vibration plate (42) and the exit/entrance plate (52) are formed of the same material and sintered integrally. |
