Bone conduction MEMS microphone

Abstract

The utility model relates to the technical field of acoustics, in particular to a bone conduction MEMS microphone. Comprising a first PCB, a second PCB and a third PCB, a vibration assembly is arranged on the lower end face of the first PCB, an electro-acoustic conversion chip MEMS and an electric signal processing chip ASIC are arranged on the lower end face of the second PCB, the electro-acoustic conversion chip MEMS and the electric signal processing chip ASIC are connected through a gold wire, the first PCB, the second PCB and the third PCB are arranged in a stacked mode, and when a wearer makes a sound, the vibration assembly is arranged on the lower end face of the first PCB, the electro-acoustic conversion chip MEMS and the electric signal processing chip ASIC are connected through a gold wire. Vibration is transmitted to the microphone through the skeleton, the vibrating diaphragm assembly starts to vibrate, so that the pressure in the cavity is changed, the changed pressure is transmitted into the vibrating diaphragm assembly, the vibrating diaphragm assembly vibrates, a vibration signal is converted into an electric signal through the electro-acoustic conversion chip MEMS, the electric signal is amplified and processed by the electric signal processing chip ASIC, and then the electric signal is output. According to the design, a mature packaging process is utilized, so that the production process of the bone conduction MEMS microphone is simpler, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of acoustics, and in particular to a bone conduction MEMS microphone. Background Art

[0002] Bone conduction microphones transmit sound signals by picking up the speaker's own bone vibrations and are widely used in the field of smart wearables.

[0003] However, the current bone conduction MEMS microphone has a relatively complex structure and is difficult to package. Utility Model Content

[0004] The purpose of the present invention is to provide a bone conduction MEMS microphone, aiming to solve the technical problems in the prior art that the bone conduction MEMS microphone has a relatively complex structure and is difficult to package.

[0005] To achieve the above objectives, the present invention adopts a bone conduction MEMS microphone, comprising a first PCB board, a second PCB board, and a third PCB board. The lower end surface of the first PCB board is provided with a vibration assembly, the lower end surface of the second PCB board is provided with an electroacoustic conversion chip MEMS and an electrical signal processing chip ASIC, and the electroacoustic conversion chip MEMS and the electrical signal processing chip ASIC are connected by gold wires. The third PCB board is bonded to the second PCB board and is located above the second PCB board. The second PCB board is bonded to the third PCB board and is located below the third PCB board. The first, second, and third PCB boards are arranged in a stacked manner.

[0006] A first air leakage hole is connected in the first PCB board, a step is provided on the lower end surface of the first PCB board, and the vibration component is located on the step.

[0007] Wherein, the second PCB board is connected with a sound hole.

[0008] The bone conduction MEMS microphone further includes a PAD, which is bonded to the third PCB and located below the third PCB.

[0009] Wherein, the PAD is a pad.

[0010] Among them, the vibration assembly includes a diaphragm, a support ring and a mass block, the diaphragm is arranged on the lower end surface of the mass block, the support ring is fixedly connected to the mass block and is sleeved on the mass block, the support ring is also bonded to the first PCB board, and the support ring and the mass block are both located at the step.

[0011] Wherein, a second air leakage hole is opened at the center of the mass block and the diaphragm, and the second air leakage holes between the mass block and the diaphragm are connected.

[0012] A bone conduction MEMS microphone includes a first PCB, a second PCB, and a third PCB. A vibration assembly is provided on the lower end surface of the first PCB. A MEMS electroacoustic conversion chip and an ASIC electrical signal processing chip are provided on the lower end surface of the second PCB. The MEMS electroacoustic conversion chip and the ASIC electrical signal processing chip are connected by gold wires. The third PCB is bonded to the second PCB and located above the second PCB. The second PCB is bonded to the third PCB and located below the third PCB. The first, second, and third PCBs are stacked. When a wearer speaks, vibration is transmitted through the bone to the microphone, causing the diaphragm assembly to vibrate, thereby changing the pressure within the cavity. The changed pressure is transmitted to the diaphragm assembly, causing it to vibrate. The MEMS electroacoustic conversion chip converts the vibration signal into an electrical signal, which is then amplified and processed by the ASIC electrical signal processing chip for output. This design utilizes mature packaging technology, simplifying the production process of the bone conduction MEMS microphone and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 This is a schematic diagram of the internal structure of the bone conduction MEMS microphone of the present invention.

[0015] 1-first PCB board, 2-second PCB board, 3-third PCB board, 4-electroacoustic conversion chip MEMS, 5-electrical signal processing chip ASIC, 6-gold wire, 7-first air bleed hole, 8-acoustic hole, 9-PAD, 10-diaphragm, 11-support ring, 12-mass block, 13-second air bleed hole. DETAILED DESCRIPTION

[0016] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0017] See also Figure 1 The present invention provides a bone conduction MEMS microphone, comprising a first PCB board 1, a second PCB board 2, and a third PCB board 3. The lower end surface of the first PCB board 1 is provided with a vibration component, the lower end surface of the second PCB board 2 is provided with an electroacoustic conversion chip MEMS 4 and an electrical signal processing chip ASIC 5, and the electroacoustic conversion chip MEMS 4 and the electrical signal processing chip ASIC 5 are connected by a gold wire 6. The third PCB board 3 is bonded to the second PCB board 2 and is located above the second PCB board 2. The second PCB board 2 is bonded to the third PCB board 3 and is located below the third PCB board 3. The first PCB board 1, the second PCB board 2, and the third PCB board 3 are arranged in a stacked shape.

[0018] In this embodiment, when the wearer speaks, the vibration is transmitted to the microphone through the bones, and the diaphragm assembly begins to vibrate, thereby causing the pressure in the cavity to change. The changed pressure is transmitted to the diaphragm assembly, causing the diaphragm assembly to vibrate, and the vibration signal is converted into an electrical signal by the electroacoustic conversion chip MEMS4, and then amplified and processed by the electrical signal processing chip ASIC5 for output. This design utilizes mature packaging technology to make the production process of bone conduction MEMS microphones simpler and improve production efficiency.

[0019] Furthermore, a first air leakage hole 7 is connected in the first PCB board 1 , a step is provided on the lower end surface of the first PCB board 1 , and the vibration component is located on the step, and the step helps to maintain airtightness and stability.

[0020] In this embodiment, the first air vent hole 7 can facilitate the balance of the internal and external air pressures of the first PCB board 1, ensuring clear sound quality without noise.

[0021] Furthermore, a sound hole 8 is connected in the second PCB board 2 .

[0022] In this embodiment, the sound hole 8 can be used to conveniently pick up the sound.

[0023] Furthermore, the bone conduction MEMS microphone further includes a PAD9 , which is bonded to the third PCB board 3 and is located below the third PCB board 3 .

[0024] In this embodiment, the PAD 9 can be used to reduce the strength of the input signal to protect subsequent devices from being damaged by excessively high signal levels, while also providing support and protection for internal structures such as chips and leads.

[0025] Furthermore, the PAD9 is a welding pad.

[0026] Furthermore, the vibration assembly includes a diaphragm 10, a support ring 11 and a mass block 12, the diaphragm 10 is arranged on the lower end surface of the mass block 12, the support ring 11 is fixedly connected to the mass block 12 and is sleeved on the mass block 12, the support ring 11 is also bonded to the first PCB board 1, and the support ring 11 and the mass block 12 are both located at the step.

[0027] In this embodiment, the diaphragm 10 captures sound fluctuations and converts them into mechanical motion. When the sound waves reach the diaphragm 10, it moves with the change of sound pressure. This movement is usually very small, but it is enough to cause the sensor connected to the diaphragm 10 to generate a changing electrical signal. A closed chamber can be formed between the mass block 12 and the diaphragm 10 to provide necessary support for the diaphragm 10 and limit the range of motion of the diaphragm 10, thereby controlling the dynamic response of the microphone.

[0028] Furthermore, a second air leakage hole 13 is formed at the center of each of the mass block 12 and the diaphragm 10 , and the second air leakage holes 13 between the mass block 12 and the diaphragm 10 are connected.

[0029] In this embodiment, the second air leakage hole 13 can facilitate balancing the internal and external air pressures of the mass block 12 and the diaphragm 10, ensuring clear sound quality without noise.

[0030] In this embodiment, the diaphragm assembly is bonded to the step of the first PCB board 1, the electroacoustic conversion chip MEMS4 and the electrical signal processing chip ASIC5 are bonded to the lower end surface of the second PCB board 2, and electrically connected through gold wires 6. Finally, the first PCB board 1, the second PCB board 2 and the third PCB board 3 are stacked together to form a bone conduction microphone device. This design is simple, has low packaging difficulty, and is conducive to improving production efficiency and reducing production costs.

[0031] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the utility model.

Claims

1. A bone conduction MEMS microphone, characterized in that: The system comprises a first PCB, a second PCB, and a third PCB. A vibration assembly is provided on the lower end surface of the first PCB. An electroacoustic conversion chip MEMS and an electrical signal processing chip ASIC are provided on the lower end surface of the second PCB. The electroacoustic conversion chip MEMS and the electrical signal processing chip ASIC are connected via gold wires. The third PCB is bonded to the second PCB and located above the second PCB. The second PCB is bonded to the third PCB and located below the third PCB. The first, second, and third PCBs are stacked.

2. The bone conduction MEMS microphone according to claim 1, wherein: A first air leakage hole is connected in the first PCB board, a step is provided on the lower end surface of the first PCB board, and the vibration component is located on the step.

3. The bone conduction MEMS microphone according to claim 2, wherein: The second PCB board is connected with a sound hole.

4. The bone conduction MEMS microphone according to claim 3, wherein: The bone conduction MEMS microphone further includes a PAD, which is bonded to the third PCB and located below the third PCB.

5. The bone conduction MEMS microphone according to claim 4, wherein: The PAD is a solder pad.

6. The bone conduction MEMS microphone according to claim 5, wherein: The vibration assembly includes a diaphragm, a support ring and a mass block. The diaphragm is arranged on the lower end surface of the mass block. The support ring is fixedly connected to the mass block and is sleeved on the mass block. The support ring is also bonded to the first PCB board, and the support ring and the mass block are both located at the step.

7. The bone conduction MEMS microphone according to claim 6, wherein: A second air leakage hole is formed at the center of each of the mass block and the diaphragm, and the second air leakage holes between the mass block and the diaphragm are communicated with each other.

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