A PZT microactuator such as for a hard disk drive has a restraining layer bonded on its side that is opposite the side on which the PZT is mounted. The restraining layer comprises a stiff and resilient material such as stainless steel. The restraining layer can cover most or all of the top of the PZT, with an electrical connection being made to the PZT where it is not covered by the restraining layer. The restraining layer reduces bending of the PZT as mounted and hence increases effective stroke length, or reverses the sign of the bending which increases the effective stroke length of the PZT even further. The restraining layer can be one or more active layers of PZT material that act in the opposite direction as the main PZT layer. The restraining layer(s) may be thinner than the main PZT layer.

A piezoelectric element includes a piezoelectric layer, a first electrode layer, a second electrode layer, and a coupling electrode. At least a portion of the second electrode layer faces the first electrode layer with the piezoelectric layer interposed therebetween. The second electrode layer includes a coupling area. The coupling area meets a through hole in a region of the second electrode layer not facing the first electrode layer. The coupling electrode is on the coupling area. Between the coupling area and the surface of the second electrode layer on the piezoelectric layer side excluding the coupling area, the difference in position is about 5 nm or less.

A piezoelectric element 10 includes a lower electrode, constituted of a Pt/Ti laminated film, a PLT seed layer, formed on the lower electrode, a PZT piezoelectric film, formed on the PLT seed layer, and an upper electrode, formed on the PZT piezoelectric film. A curve Q1 is a curve drawn such as to pass through a plurality of plotted points, each expressing a PLT (100) peak intensity with respect to a Pt (111) peak intensity according to a substrate setting temperature during forming of the Pt/Ti laminated film. A relationship of the PLT (100) peak intensity with respect to the Pt (111) peak intensity is within a range in the curve Q1 until the PLT (100) peak intensity decreases by 5% from a peak point P, at which the PLT (100) peak intensity is the maximum, and a (100) orientation rate of PLT constituting the seed layer is not less than 85%.

A piezoelectric element 10 includes a lower electrode, constituted of a Pt/Ti laminated film, a PLT seed layer, formed on the lower electrode, a PZT piezoelectric film, formed on the PLT seed layer, and an upper electrode, formed on the PZT piezoelectric film. A curve Q1 is a curve drawn such as to pass through a plurality of plotted points, each expressing a PLT (100) peak intensity with respect to a Pt (111) peak intensity according to a substrate setting temperature during forming of the Pt/Ti laminated film. A relationship of the PLT (100) peak intensity with respect to the Pt (111) peak intensity is within a range in the curve Q1 until the PLT (100) peak intensity decreases by 5% from a peak point P, at which the PLT (100) peak intensity is the maximum, and a (100) orientation rate of PLT constituting the seed layer is not less than 85%.

The present disclosure provides a manufacturing method for a piezoelectric ceramic chip, a piezoelectric ceramic chip assembly and a display device. The manufacturing method includes: transferring a piezoelectric ceramic layer and a bottom electrode covering the piezoelectric ceramic layer formed on a substrate to a base plate, forming an insulating layer with an opening on the base plate, so that edges of the piezoelectric ceramic layer and the bottom electrode are covered by the insulating layer, and the piezoelectric ceramic layer is exposed from the opening; etching the base plate by immersing the base plate in an etching solution for etching a material of the bottom electrode; and forming a top electrode in the opening of the insulating layer, so that the top electrode is spaced apart from the insulating layer.

In some embodiments, a piezoelectric device is provided. The piezoelectric device includes a semiconductor substrate. A first electrode is disposed over the semiconductor substrate. A piezoelectric structure is disposed on the first electrode. A second electrode is disposed on the piezoelectric structure. A heating element is disposed over the semiconductor substrate. The heating element is configured to heat the piezoelectric structure to a recovery temperature for a period of time, where heating the piezoelectric structure to the recovery temperature for the period of time improves a degraded electrical property of the piezoelectric device.

In some embodiments, a piezoelectric device is provided. The piezoelectric device includes a semiconductor substrate. A first electrode is disposed over the semiconductor substrate. A piezoelectric structure is disposed on the first electrode. A second electrode is disposed on the piezoelectric structure. A heating element is disposed over the semiconductor substrate. The heating element is configured to heat the piezoelectric structure to a recovery temperature for a period of time, where heating the piezoelectric structure to the recovery temperature for the period of time improves a degraded electrical property of the piezoelectric device.

A multilayer ultrasonic transducer of an embodiment includes: a plurality of stacked oscillators; external electrodes disposed on outer exposed surfaces of two oscillators disposed in the outermost layers out of the plurality of oscillators; and a plurality of internal electrodes each disposed between two of the plurality of oscillators. There are provided electrode regions in which the plurality of internal electrodes are arranged such that the number of layers of the internal electrodes in a direction in which the oscillators are stacked gradiently increases from an inner region toward an outer peripheral region of the plurality of oscillators, and ultrasonic waves emitted from the plurality of oscillators are focused toward at least the inner region.

A multi-layer piezoelectric microactuator assembly has at least one poled and active piezoelectric layer and one poled but inactive piezoelectric layer. The poled but inactive layer acts as a constraining layer in resisting expansion or contract of the first piezoelectric layer thereby reducing or eliminating bending of the assembly as installed in an environment, thereby increasing the effective stroke length of the assembly. Poling only a single layer would induce stresses into the device; hence, polling both piezoelectric layers even though only one layer will be active in use reduces stresses in the device and therefore increases reliability.

A multi-layer piezoelectric microactuator assembly has at least one poled and active piezoelectric layer and one poled but inactive piezoelectric layer. The poled but inactive layer acts as a constraining layer in resisting expansion or contract of the first piezoelectric layer thereby reducing or eliminating bending of the assembly as installed in an environment, thereby increasing the effective stroke length of the assembly. Poling only a single layer would induce stresses into the device; hence, polling both piezoelectric layers even though only one layer will be active in use reduces stresses in the device and therefore increases reliability.