Vibration Sensor

One of the main objects of the present invention is to provide a vibration sensor with improved sensitivity. To achieve the above-mentioned objects, the present invention provides a vibration sensor including a circuit board assembly including an installation slot; a housing fixed to the circuit board assembly for forming an accommodation space cooperatively with the circuit board assembly; and a diaphragm assembly accommodated in the accommodation space and secured to the circuit board assembly. The diaphragm assembly includes a gasket fixed to the circuit board assembly, and a first diaphragm fixed to a side of the gasket away from the circuit board assembly.

FIELD OF THE PRESENT DISCLOSURE

The present invention relates to electromechanical transducers, and more particularly to vibration sensor for converting vibration to electrical signals.

DESCRIPTION OF RELATED ART

With the development of technology, microphone equipment is evolving from traditional air conduction microphones to bone conduction microphones. Generally, the bone conduction microphone senses the bone vibration when the user utters through the diaphragm assembly, and then transmits it to the MEMS microphone by the diaphragm assembly. Finally, the MEMS microphone converts the vibration signal into an electrical signal for recording or transmission. However, the positions of the diaphragm assembly and the MEMS microphone in the bone conduction microphone of the prior art are unreasonable. As a result, the diaphragm assembly cannot effectively transmit the vibration signal to the MEMS microphone, which is prone to insensitivity.

Therefore, it is necessary to provide a new vibration sensor to solve the above problems.

SUMMARY OF THE PRESENT INVENTION

One of the main objects of the present invention is to provide a vibration sensor with improved sensitivity.

To achieve the above-mentioned objects, the present invention provides a vibration sensor including a circuit board assembly including an installation slot; a housing fixed to the circuit board assembly for forming an accommodation space cooperatively with the circuit board assembly; and a diaphragm assembly accommodated in the accommodation space and secured to the circuit board assembly. The diaphragm assembly includes a gasket fixed to the circuit board assembly, and a first diaphragm fixed to a side of the gasket away from the circuit board assembly.

The vibration sensor further includes a vibration cavity enclosed by the gasket, the first diaphragm, and the circuit board assembly, and a MEMS microphone accommodated in vibration cavity and installed in the installation slot. The installation slot locates above and communicates with the vibration cavity

In addition, the MEMS microphone includes a substrate installed in the installation slot, a second diaphragm and a back plate respectively fixed to the substrate on a side close to the first diaphragm; the first diaphragm, the back plate and the second diaphragm are sequentially arranged at intervals.

In addition, the MEMS microphone separates the vibration cavity into a front cavity located between the diaphragm assembly and the MEMS microphone, and a back cavity located inside the MEMS microphone

In addition, the vibration sensor further includes an ASIC chip accommodated in the accommodation space and electrically connected to the circuit board assembly; the gasket isolates the ASIC chip from the MEMS microphone.

In addition, the circuit board assembly includes an internal wiring provided; the MEMS microphone includes a first gold wire; the ASIC chip includes a second gold wire; the internal wiring electrically connects the first gold wire and the second gold wire.

In addition, the housing includes a sidewall fixed to the circuit board assembly and a top wall fixed to the sidewall away from the circuit board assembly; the housing includes at least one first vent hole penetrating therethrough.

In addition, the diaphragm assembly includes at least one second vent hole penetrating therethrough; the vibration cavity is connected to the accommodation space through the at least one second vent hole.

In addition, the diaphragm assembly further includes a weight arranged on a side of the first diaphragm close to the circuit board assembly and/or the side of the first diaphragm away from the circuit board assembly.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

The present disclosure will hereinafter be described in detail with reference to an exemplary embodiment. To make the technical problems to be solved, technical solutions and beneficial effects of the present disclosure more apparent, the present disclosure is described in further detail together with the FIGURE and the embodiment. It should be understood the specific embodiment described hereby is only to explain the disclosure, not intended to limit the disclosure.

Please refer toFIG. 1. This present invention provides a vibration sensor100. the vibration sensor100includes a circuit board assembly1, a housing2, a diaphragm assembly3, an MEMS microphone4, and an ASIC chip5.

Specifically, the circuit board assembly1is provided with an installation slot11; the housing2includes a sidewall21fixed to the circuit board assembly1and a top wall22fixed to the sidewall21on the side away from the circuit board assembly1. The circuit board assembly1, the sidewall21and the top wall22are enclosed to form accommodation space10. Diaphragm assembly3, MEMS microphone4and ASIC chip5are all accommodated in accommodation space10and fixed on circuit board assembly1respectively. Both the MEMS microphone4and the ASIC chip5are electrically connected to the circuit board assembly1. And the circuit board assembly1includes an internal wiring12provided thereon. MEMS microphone4is provided with first gold wire40. ASIC chip5has a second gold wire50. The internal wiring12electrically connects the first gold wire40and the second gold wire50at the same time.

In this embodiment, a first vent hole20is provided on the top wall22, and the first vent hole20is arranged to balance the internal and external air pressure of the vibration sensor100. Specifically, the accommodation space10communicates with the outside through the first vent hole20. When the housing2is assembled on the circuit board assembly1, the excess gas can be discharged through the first vent hole20. This effectively avoids the formation of high pressure in the accommodation space10during the assembly process. It should be noted that, in other embodiments, the specific number and specific positions of the first vent hole20are not limited to those shown inFIG. 1. The actual implementation can be adjusted according to needs.

The diaphragm assembly3includes a gasket31fixed on the circuit board assembly1, a first diaphragm32fixed on the side of the gasket31away from the circuit board assembly1, and a weight33fixed on the side of the first diaphragm32away from the circuit board assembly1. The circuit board assembly1, the gasoline31, and the first diaphragm32are enclosed to form a vibration cavity30. The vibration cavity30is located directly above the installation slot11and the two are connected. The MEMS microphone4is installed in the vibration cavity30and installed in the installation slot11. The MEMS microphone4is accommodated in the vibration cavity30and installed in the installation slot11, so that the volume of the vibration cavity30is reduced. The vibration signal of the diaphragm assembly3can be more effectively transmitted to the MEMS microphone4, thereby improving the sensitivity of the vibration sensor100. And the gasket31separates the MEMS microphone4from the ASIC chip5, which improves the reliability of the vibration sensor100.

The weight33increases the inertia of diaphragm assembly3, thereby increasing the sensitivity of diaphragm assembly3. It should be noted that in other embodiments, the weight33can also be set in other positions of the first diaphragm32, or set in the first diaphragm32in other forms.

In this embodiment, a second vent hole34is provided on the first diaphragm32. The setting of the second vent hole34can balance the air pressure inside and outside the vibration cavity30. Specifically, the vibration cavity30is connected to the accommodation space10through the second vent hole34. When the diaphragm assembly3vibrates, the gas in the vibration cavity30and the accommodation space10can flow through the second vent hole34. The air pressure in the vibration cavity30and in the accommodation space10is balanced. The accommodation space10and the vibration cavity30on both sides of the diaphragm assembly3are avoided to form a closed space. When the diaphragm assembly3is caused to vibrate, high pressure or low pressure is formed in the accommodation space10and the vibration cavity30to affect the vibration amplitude of the diaphragm assembly3. Thereby affecting the sensitivity of the vibration sensor100. It should be noted that, in other embodiments, the specific number and specific positions of the second vent hole34are not limited to those shown inFIG. 1. The actual implementation can be adjusted according to needs.

The MEMS microphone4includes a substrate41fixed in the installation slot11, a second diaphragm42and a back plate43respectively fixed on the side of the substrate41close to the first diaphragm32. The first diaphragm32, the back plate43, and the second diaphragm42are sequentially arranged at intervals. The substrate41and the back plate43divide the vibration cavity30into a front cavity301and a back cavity302. The front cavity301is located between the diaphragm assembly3and the MEMS microphone4. The back cavity302is located inside the MEMS microphone4.

When the vibration sensor100receives a vibration signal or a pressure signal, the diaphragm assembly3vibrates. Specifically, the weight33vibration drives the first diaphragm32to vibrate, so that the gas in the vibration cavity30vibrates. As a result, the second diaphragm42of the MEMS microphone4located in the vibration cavity30vibrates. The distance between the second diaphragm42and the back plate43changes during the vibration process, that is, the size of the capacitance generated by the MEMS microphone4is changed. In this way, the vibration signal or pressure signal is converted into a corresponding electrical signal.

And in this embodiment, the MEMS microphone4is installed in the vibration cavity30and separated from the diaphragm assembly3. The small size of the front cavity301enables the vibration of the weight33to be transmitted to the second diaphragm42more effectively. Thereby improving the sensitivity of the vibration sensor100.