MEMS speaker and speaker assembly structure

Patent metadata

Field	Value
Publication number	US-11895464-B2
Application number	US-202217880701-A
Country	US
Kind code	B2
Filing date	Aug 4, 2022
Priority date	Dec 31, 2021
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

A MEMS speaker includes a substrate, a vibration sounding portion and a baffle plate with a through hole. The baffle plate, the substrate and the vibration sounding portion form a sounding inner cavity, and a volume of the sounding inner cavity can adjust a resonant frequency of the sounding inner cavity, so that the resonance frequency of the sounding inner cavity resonate with a preset frequency of the MEMS speaker. A speaker assembly structure further provided includes a speaker, a fixing portion, and a baffle plate, the speaker and the baffle plate together enclose and form a sounding inner cavity, the fixing portion and the speaker are fixedly connected together and form a sealing structure. A sound pressure level of the MEMS speaker and the speaker assembly structure is high and harmonic distortion of the MEMS speaker and the speaker assembly structure is small.

First claim

What is claimed is:

1. A Micro-Electro-Mechanical-Systems (MEMS) speaker, comprising:
a substrate;
a vibration sounding portion; and
a baffle plate;
wherein a first end and a second end of the substrate are open and the substrate is a hollow shape; the vibration sounding portion is configured to emit a sound wave within a range of human ear auditory frequency when excited by an electrical signal, and the vibration sounding portion is fixed to and covered on the first end of the substrate, and the sound wave generated by vibration of the vibration sounding portion conforms to a classical sound wave theorem; the baffle plate is covered and fixed on the second end of the substrate; the baffle plate, the substrate, and the vibration sounding portion together form a sounding inner cavity, a volume of the sounding inner cavity is configured to adjust a resonance frequency of the sounding inner cavity, so that the resonance frequency of the sounding inner cavity resonates with a preset frequency of the MEMS speaker; a through hole is defined on the baffle plate, the sounding inner cavity communicates with an outside world through the through hole, and a volume of the through hole is configured to adjust a sound pressure level and harmonic distortion of the MEMS speaker within a working frequency range.

2. The MEMS speaker according to claim 1 , wherein a number of the through hole is one or more.

3. The MEMS speaker according to claim 1 , wherein a cross-sectional, of the through hole, being perpendicular to a vibration direction is one of a circle, an oval, a square, a rectangle, and a triangle.

4. The MEMS speaker according to claim 1 , wherein the MEMS speaker is a piezoelectric speaker made by a MEMS process.

5. The MEMS speaker according to claim 1 , wherein the vibration sounding portion is driven by an electromagnetic signal, a piezoelectric signal or an electrostatic signal.

6. The MEMS speaker according to claim 1 , wherein the substrate and the baffle plate are connected by a bonding process.

7. The MEMS speaker according to claim 1 , wherein a cross-sectional, of the through hole, being perpendicular to a vibration direction is one of a circle, an oval, a square, a rectangle, and a triangle.

Assignees

• Aac Microtech Changzhou Co Ltd

Inventors

• Shen Yu
• Cheng Shiyang
• Zhou Yiwei
• Dan qiang
• Li Yang

Classifications

• H04R19/02 Primary

  Loudspeakers (H04R19/01 takes precedence) · CPC title

• H04R1/2811 Primary

  for loudspeaker transducers · CPC title

• H04R2201/003

  Mems transducers or their use · CPC title

• H04R2499/11

  Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's · CPC title

• H04R17/10

  Resonant transducers, i.e. adapted to produce maximum output at a predetermined frequency · CPC title