Abstract: This application provides a bulk acoustic wave resonator and a bulk acoustic wave filter, and relates to the technical field of filters. The bulk acoustic wave resonator includes a substrate, and a bottom electrode, a piezoelectric layer, a top electrode which are sequentially stacked on the substrate, and an outline of an orthographic projection of the top electrode on the substrate is formed by four curves which are end-to-end connected. Arc transition is set at a joint of every two adjacent curves, and every two curves arranged in a spaced manner are not parallel. Accordingly, reliability of devices can be effectively improved, meanwhile, parasitic resonance amplitude can be effectively restrained, a Q value is increased, and thus device properties are improved.

Abstract: A piezoelectric microphone, includes: a wafer substrate including a cavity; a plurality of cantilever beams with a piezoelectric deck structure; a fixed column; a plurality of flexible elastic members; and a connecting section. The plurality of cantilever beams each includes a fixed end and a free end suspended above the cavity. The plurality of cantilever beams is of a structure in which one end is narrow and the other end is wide, and the fixed end is relatively narrow. The fixed column is disposed at the center of the bottom surface of the cavity. The fixed ends of the plurality of cantilever beams are all connected to the top surface of the fixed column. A gap is provided between every two adjacent cantilever beams. The plurality of flexible elastic members is connected to free ends of two adjacent cantilever beams to enable the cantilever beams to vibrate synchronously.

Abstract: The present application discloses a piezoelectric micro electrical mechanical system (MEMS) microphone chip and a piezoelectric MEMS microphone, and relates to the technical field of piezoelectric devices. The piezoelectric MEMS microphone chip includes at least one substrate frame and at least one plurality of sound receiving beams arranged on the substrate frame. Each of the sound receiving beams includes a connecting beam and a cantilever beam. The connecting beam and the cantilever beam are staggered on a circumference. One ends of the plurality of sound receiving beams that face a geometric center of the a circumference are fixedly connected to one another in a center defined by the substrate frame, and one end of the connecting beam that is away from the geometric center is fixedly connected to the substrate frame.

Abstract: The disclosure provides a packaging structure and method of an acoustic device, relating the technical field of semiconductors, including: a substrate and a piezoelectric stack structure located on the substrate, a first organic material layer is disposed on the piezoelectric stack structure, a second organic material layer is disposed on the first organic material layer, the first organic material layer includes a first supporting part and a second supporting part, the second supporting part forms a first acoustic reflection structure, when being transmitted to the first acoustic reflection structure, acoustic waves can be reflected back to the effective area, so that the loss of the acoustic waves is reduced, and the performance of the acoustic device is improved.