CN-115914975-B - Pixel sounding unit, manufacturing method thereof and digital sounding chip

CN115914975BCN 115914975 BCN115914975 BCN 115914975BCN-115914975-B

Abstract

The invention discloses a pixel sounding unit, a manufacturing method thereof and a digital sounding chip, which are applied to the technical field of digital sounding chips to solve the problem of low working frequency of a loudspeaker diaphragm. The pixel sounding unit comprises a vibrating plate, an electrode plate and an air rear cavity, wherein a plurality of sub-vibrating areas are divided on the vibrating plate, each sub-vibrating area is respectively etched with a sub-vibrating diaphragm, the vibrating plate, the electrode plate and the air rear cavity are sequentially arranged, and the plurality of sub-vibrating areas share one electrode plate and the air rear cavity. The digital sounding chip comprises the pixel sounding unit provided by the scheme. The manufacturing method of the pixel sounding unit adopts the pixel sounding unit provided by the scheme.

Inventors

LIU CHANGHUA
JIN YIZE
YUAN FEIYANG

Assignees

地球山(苏州)微电子科技有限公司

Dates

Publication Date: 20260512
Application Date: 20221208

Claims (9)

1. A pixel sounding unit, comprising: The vibrating plate is divided into a plurality of sub-vibrating areas, each sub-vibrating area is respectively etched with a sub-vibrating diaphragm, each sub-vibrating area is provided with at least two sub-dividing grooves which are arranged in a surrounding mode, one end part of each adjacent sub-dividing groove and the other end part of each adjacent sub-dividing groove are sequentially arranged along the radial direction which extends outwards from the center point of each sub-vibrating area so as to form overlapping in the surrounding mode, and a sub-vibrating diaphragm cantilever structure is formed between the overlapping sub-dividing grooves; An electrode plate; the vibrating plate, the electrode plates and the air rear cavity are sequentially arranged, and the plurality of sub-vibrating areas share one electrode plate and the air rear cavity.
2. The pixel sound generating unit according to claim 1, wherein the vibration plate is composed of at least two sub-vibration regions of equal area, a plurality of the sub-vibration regions are arranged in an array, and the sub-diaphragms on each of the sub-vibration regions are identical in size.
3. The pixel sounding unit according to claim 1, further comprising a substrate, the electrode plate and the vibration plate being sequentially stacked, the substrate having an opening, a structure between a side of the sub-diaphragm of the vibration plate facing the electrode plate and a bottom of the opening forming the air rear cavity; and a support column for supporting the electrode plate is arranged in the substrate.
4. The pixel sounding unit according to claim 1, wherein the vibration plate is provided with a plurality of first dividing grooves, a plurality of second dividing grooves and a plurality of connecting dividing grooves; four first dividing grooves which are annularly distributed are formed in each sub-vibration area, and the sub-vibration films are surrounded by the four first dividing grooves; the plurality of second dividing grooves are surrounded to form an annular structure, the first dividing grooves are positioned at the inner side of the annular structure, and the second dividing grooves are positioned at the outer sides of the front adjacent first dividing grooves and the rear adjacent first dividing grooves; The first dividing grooves of two adjacent sub-vibration areas are connected through two parallel connecting dividing grooves.
5. The pixel sounding unit of claim 1, further comprising a spacer, a gap being formed between the electrode plate and the vibration plate by the spacer.
6. The pixel sounding unit of claim 5, wherein the spacer is made of an insulating material.
7. A digital sounding chip, comprising the pixel sounding units according to any one of claims 1 to 6, wherein the number of the pixel sounding units is plural, and the pixel sounding units are distributed in an array or in a linear shape.
8. A method of manufacturing a pixel sound generating unit according to any one of claims 1 to 6, comprising: A plurality of sub-vibration areas are divided on the vibration plate of the pixel sounding unit, And etching each sub-vibration area to form a sub-vibrating diaphragm.
9. The method of manufacturing a pixel sounding unit according to claim 8, wherein etching the sub-diaphragms on each of the sub-vibration regions includes: etching sub-dividing grooves on each sub-vibrating area respectively to form sub-vibrating films located in surrounding areas of the sub-dividing grooves, sub-fixing parts located outside the surrounding areas of the sub-dividing grooves and sub-vibrating film cantilever structures connecting the sub-vibrating films and the sub-fixing parts on each sub-vibrating area respectively; before the step of etching the sub-dividing grooves on each sub-vibration area, the method further comprises the following steps: establishing a rigidity model of the sub-diaphragm, and designing the number and the size of cantilever structures of the sub-diaphragm according to the rigidity model of the sub-diaphragm; And designing the size of the sub-dividing grooves according to the number and the size of the designed sub-diaphragm cantilever structures.

Description

Pixel sounding unit, manufacturing method thereof and digital sounding chip Technical Field The invention relates to the technical field of digital sounding chips, in particular to a pixel sounding unit, a manufacturing method thereof and a digital sounding chip. Background A speaker is a transducer device capable of converting an electrical signal into an acoustic signal. The speaker is the basis for making sound, acoustically active noise reduction devices, etc., and therefore, the performance of the speaker has a critical impact on the fabrication of acoustic devices. MEMS speaker (Micro Electro MECHANICAL SYSTEM), i.e. Micro-electromechanical system speaker, has advantages such as uniformity is good, the consumption is low, the size is little, low price compared with traditional voice coil loudspeaker. At present, the common MEMS loudspeaker is used for realizing simulated sounding by pushing air through vibration film movement, and in general, the vibration film in the MEMS loudspeaker is of a monolithic film structure, and sounding can be realized through monolithic vibration film movement when the structure is adopted, but the vibration film resonant frequency of the structure is lower, and the working efficiency is poor. Disclosure of Invention The invention aims to provide a pixel sounding unit, a manufacturing method thereof and a digital sounding chip, so as to improve the resonant frequency and the working efficiency of a vibrating diaphragm. In order to achieve the above object, the present invention provides the following technical solutions: A pixel sounding unit comprising: the vibrating plate is divided into a plurality of sub-vibrating areas, and each sub-vibrating area is etched with a sub-vibrating diaphragm respectively; An electrode plate; The air rear cavity, the vibrating plate, the electrode plates and the air rear cavity are sequentially arranged, and the plurality of sub-vibrating areas share one electrode plate and the air rear cavity. Compared with the prior art, in the pixel sounding unit provided by the invention, the plurality of sub-vibrating areas are divided on the vibrating plate, each sub-vibrating area is respectively etched with the sub-vibrating diaphragm, the resonance frequency of the sub-vibrating diaphragm can be improved by dividing the whole vibrating diaphragm into the plurality of sub-vibrating diaphragms, so that the working frequency of the sub-vibrating diaphragm is improved, the upper limit of the sounding frequency of the sub-vibrating diaphragm is improved, the sound pressure level of sounding is improved, the distortion is reduced, the sensitivity is improved, and the sounding effect of the pixel sounding unit is improved. Optionally, in the pixel sounding unit, the vibrating plate is composed of at least two sub-vibrating areas with equal areas, the plurality of sub-vibrating areas are arranged in an array, and the sizes of the sub-vibrating films on each sub-vibrating area are the same. The number of the sub-vibration areas is optimized, and the resonance frequency and the working frequency of the sub-diaphragm are improved. Optionally, in the pixel sounding unit, the pixel sounding device further includes a substrate, the electrode plate and the vibrating plate are sequentially stacked, the substrate has an opening, and an air rear cavity is formed by a structure between one side of the vibrating plate, which faces the electrode plate, and the bottom of the opening; Support columns for supporting the electrode plates are arranged in the substrate. So set up, support the electrode plate through the support column, improve the installation stability of electrode plate, and then improve the overall stability of pixel sound production unit. Optionally, in the pixel sounding unit, at least two sub-dividing grooves are formed in each sub-vibrating area, the sub-dividing grooves are arranged in a surrounding mode, one end portion of each sub-dividing groove and the other end portion of each sub-dividing groove are sequentially arranged along a radial direction extending outwards from a central point of each sub-vibrating area, overlapping sub-dividing grooves are formed in the surrounding mode, a sub-vibrating diaphragm cantilever structure is formed between the overlapping sub-dividing grooves, the sub-dividing grooves divide the sub-vibrating area into a sub-vibrating diaphragm located in the surrounding area of the sub-dividing grooves and a sub-fixing portion located outside the surrounding area of the sub-dividing grooves, the sub-vibrating diaphragm is elastically connected with the sub-fixing portion through the sub-vibrating diaphragm cantilever structure, and the sub-vibrating diaphragm, the sub-fixing portion and the sub-vibrating diaphragm cantilever structure are of an integrated structure. When two adjacent sub-dividing grooves overlap, the length of the cantilever structure of the sub-diaphragm between the two adjacent sub-dividing grooves can