KR101610173B1 - Microphone system and control method of microphone - Google Patents

Abstract

The present invention relates to a microphone system, and more particularly, to a microphone system that can maximize sensitivity by using a plurality of microphones having different resonance frequencies and a method for controlling the microphone. To achieve this, the microphone system according to an embodiment of the present invention may include: a phone assembly including a plurality of microphones having different resonance frequencies; a microphone array including a plurality of phone assemblies; a connection assembly including switches connected to the plurality of phone assemblies included in the microphone array; and a semiconductor chip connected to the microphone array through the connection assembly and configured to receive a sound signal from the microphone array and switch off the switch according to the magnitude of the sound signal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a microphone system,

The present invention relates to a microphone system, and more particularly, to a microphone system and a microphone control method capable of maximizing sensitivity using a plurality of microphones having different resonance frequencies.

In general, a microphone is a device that converts voice to electrical signals. The microphone should have good electronic and acoustic performance, reliability and operability. These microphones are becoming smaller and smaller. Accordingly, microphones using MEMS (Micro Electro Mechanical System) technology are being developed.

MEMS microphones are manufactured using semiconductor batch processes. MEMS microphones are more resistant to moisture and heat than conventional electret condenser microphones (ECM), and can be miniaturized and integrated with a signal processing circuit. In addition, the MEMS microphone has an advantage in that it has superior sensitivity and lower performance deviation than the conventional ECM.

In general, MEMS microphones are divided into piezoelectric MEMS microphones and capacitive MEMS microphones.

A piezoelectric MEMS microphone is composed of a diaphragm, and when the diaphragm is deformed by external music, an electric signal is generated by a piezoelectric effect to measure the sound pressure.

Capacitive MEMS microphones consist of a fixed electrode and a diaphragm. When music is applied to the diaphragm from the outside, the distance between the fixed electrode and the diaphragm changes and the capacitance value changes. The sound pressure is measured by the electric signal generated at this time.

Capacitive MEMS microphones have advantages such as excellent sensitivity, low power consumption, stable frequency response and low noise level. However, a capacitive MEMS microphone needs to apply a DC voltage from the outside, and there is a restriction on a maximum input sound pressure (AOP) and a frequency response range due to a pull-in phenomenon. On the other hand, in order to increase the sensitivity of the capacitive MEMS microphone, the rigidity of the diaphragm must be lowered, but the frequency response range is narrowed and there is a limit due to the pull-in phenomenon.

A related art is Korean Patent No. 10-0804513 entitled "Acoustic Sensor Using Piezoelectric Cantilever Beam ". In the prior art, a sensor for measuring a signal of a sound wave and an acoustic wave by using a resonant frequency of a multi-cantilever beam made of a piezoelectric material, and a technique in which various frequency response ranges depending on the shape and dimensions of the cantilever can be applied to the measurement of sound waves and elasticity . However, the piezoelectric microphone according to the related art has a relatively low sensitivity and SNR as compared with the capacitance type microphone, and the piezoelectric cantilever has to be manually formed, so that the batch process is impossible and thus mass production is limited.

The matters described in the background section are intended to enhance the understanding of the background of the invention and may include matters not previously known to those skilled in the art.

Embodiments of the present invention provide a microphone system and a microphone control method for arranging a plurality of microphones having different resonance frequencies.

The embodiments of the present invention provide a microphone system and a microphone control method that connect a microphone array and a semiconductor chip with a switch and select a frequency response range through a switch.

In one embodiment of the present invention, a pawn assembly including a plurality of microphones having different resonance frequencies; A microphone array having a plurality of the pawn assemblies; A connection assembly including a switch coupled to each of a plurality of pawn assemblies included in the microphone array; And a semiconductor chip connected to the microphone array through the connection assembly, receiving a sound signal from the microphone array, and turning off the switch according to a signal size of the sound signal.

The microphone may further include: a diaphragm disposed on the substrate; A first pad connected to the diaphragm; A fixed electrode disposed on the diaphragm and spaced apart from the diaphragm; And a second pad connected to the fixed electrode.

The first pad of each of the plurality of microphones included in the phone assembly may be connected through a pad connection line, and the second pad of each of the plurality of microphones may be connected through an electrode connection line.

One side of the switch may be connected to the pad connection line and the electrode connection line, and the other side of the switch may be connected to the semiconductor chip.

In addition, the phone assembly may arrange a plurality of microphones such that different resonance frequencies are continuous.

Further, the resonance frequency may be set using a spring constant by the diaphragm and a mass of the diaphragm.

Also, the semiconductor chip may check the signal size for each of the pawn assemblies, and turn off a switch connected to the pawn assembly whose signal size is greater than or equal to a predetermined set size of the plurality of pawn assemblies.

In addition, the microphone array may be formed on a single wafer.

In another embodiment of the present invention, a plurality of piano assemblies including a plurality of microphones having different resonance frequencies, a method of controlling a microphone by a semiconductor chip connected to each of the plurality of pony assemblies through a switch, Receiving an acoustic signal from the microphone; Confirming a signal size of the acoustic signal; And turning off at least one of the switches connected to each of the plurality of phone assemblies according to the signal magnitude.

The embodiment of the present invention can maximize the sensitivity and the signal-to-noise ratio (SNR) by arranging a plurality of microphones having different resonance frequencies.

In addition, since the microphone array is implemented on a single wafer using the batch process, mass production is possible.

In addition, effects obtainable or predicted by the embodiments of the present invention will be directly or implicitly disclosed in the detailed description of the embodiments of the present invention. That is, various effects to be predicted according to the embodiment of the present invention will be disclosed in the detailed description to be described later.

1 is a schematic view of a microphone system according to an embodiment of the present invention.
2 is a cross-sectional view of a microphone according to an embodiment of the present invention.
FIG. 3 is a graph illustrating sensitivity according to an exemplary embodiment of the present invention. Referring to FIG.
4 is an exemplary view showing a dynamic range for each of a plurality of pony assemblies according to an embodiment of the present invention.
5 is a flowchart illustrating a microphone control method according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an operation principle of an embodiment of a microphone system and a microphone control method according to the present invention will be described in detail with reference to the accompanying drawings and description. It should be understood, however, that the drawings and the following detailed description are exemplary and explanatory of various embodiments for effectively illustrating the features of the present invention. Therefore, the present invention should not be limited to the following drawings and descriptions.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The terms used below are defined in consideration of the functions of the present invention, which may vary depending on the user, intention or custom of the operator. Therefore, the definition should be based on the contents throughout the present invention.

In order to efficiently explain the essential technical features of the present invention, the following embodiments will appropriately modify, integrate, or separate terms to be understood by those skilled in the art to which the present invention belongs , And the present invention is by no means thereby limited.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view of a microphone system according to an embodiment of the present invention.

Referring to FIG. 1, a microphone system 50 includes a microphone array 100, a connection assembly 170, and a semiconductor chip 190.

The microphone array 100 includes a plurality of pawn assemblies. Hereinafter, the microphone array 100 will be described as including six piano assemblies as shown in FIG. 1, but the present invention is not limited thereto. The number of piano assemblies included in the microphone array 100 is not limited Do.

Each of the first to sixth phone assemblies 110, 120, 130, 140, 150, and 160 includes a plurality of microphones 115. These plurality of microphones 115 are formed on a single wafer. Accordingly, the microphone system 50 according to an embodiment of the present invention can be mass-produced because a plurality of microphones 115 are formed on a single wafer.

Here, each of the plurality of microphones 115 includes a substrate 210, a diaphragm 230, and a fixed electrode 260 as shown in FIG.

The substrate 210 may be made of silicon, and a through hole 215 is formed.

The oxide film 220 is disposed on the substrate 210. That is, the oxide film 220 may be disposed between the substrate 210 and the diaphragm 230.

The diaphragm 230 is disposed on the oxide film 220 and covers the through hole 215 formed in the substrate 210. A part of the diaphragm 230 is exposed by the through hole 215 and a part of the diaphragm 230 exposed by the through hole 215 vibrates according to the sound introduced from the outside.

The diaphragm 230 may have a circular shape and include a plurality of slots 235. The slot 235 is disposed on the through hole 215.

The first pad 240 is disposed on the diaphragm 230. The first pad 240 is connected to the connection assembly 170.

The supporting layer 250 is disposed at the edge portion of the diaphragm 230 and supports the fixed electrode 260. The support layer 250 is formed with a contact hole 255 for exposing the first pad 240.

The fixed electrode 260 is disposed apart from the diaphragm 230. The fixed electrode 260 includes a plurality of air inlets 265. The fixed electrode 260 is disposed and fixed on the support layer 250. Here, the fixed electrode 260 may be formed of polysilicon or metal.

An air layer is formed between the fixed electrode 260 and the diaphragm 230. The fixed electrode 260 and the diaphragm 230 are spaced apart from each other by a predetermined distance. Sound is introduced through the air inlet 265 formed in the fixed electrode 260 to excite the diaphragm 230, and the diaphragm 230 vibrates. At this time, the interval between the fixed electrode 260 and the diaphragm 230 is changed, and thus the acoustic signal between the diaphragm 230 and the fixed electrode 260 is changed. The changed acoustic signal is output to the semiconductor chip 190 through the first pad 240 connected to the diaphragm 230 and the second pad 270 connected to the fixed electrode 260.

The second pad 270 is disposed on the fixed electrode 260. The second pad 270 is connected to the connection assembly 170.

Each of the first to sixth piano assemblies 110, 120, 130, 140, 150, and 160 includes a plurality of microphones 115 having different resonance frequencies. Specifically, each of the first to sixth piano assemblies 110, 120, 130, 140, 150, and 160 arranges a plurality of microphones 115 such that different resonance frequencies are continuous. Each of the plurality of microphones 115 can change the resonance frequency by changing the diaphragm 230. That is, the resonance frequency can be set based on the spring constant by the diaphragm 230 of the microphone 115 and the mass of the diaphragm 230. In other words, the resonant frequency can be set by the following equation (1).

[Equation 1]

Here, f denotes a resonance frequency, k denotes a spring constant, and m can denote the mass of the diaphragm 230. The spring constant can be calculated based on the sound pressure of the sound acting on the diaphragm 230 and the amount of change of the diaphragm 230 because the diaphragm 230 vibrates by the sound flowing from the outside.

Since the acoustic signals are processed using the plurality of microphones 115 having different resonance frequencies, the sensitivity and the SNR can be maximized.

The first to sixth pawn assemblies 110, 120, 130, 140, 150, and 160 may have different frequency response ranges by a plurality of microphones 115 having continuous resonance frequencies. That is, the frequency response range of the first to sixth phone assemblies 110, 120, 130, 140, 150, and 160 may gradually increase or decrease. For example, each of the first to sixth pawn assemblies 110, 120, 130, 140, 150, and 160 may have different frequency response ranges as shown in FIG. 3, The frequency response range may be increased toward the sixth pawn assembly 160. [ That is, as shown in FIG. 3, the frequency response range of the first pawn assembly 110 corresponds to reference numeral 310, the frequency response range of the second pawn assembly 120 corresponds to reference numeral 320, The frequency response range of the third pony assembly 130 corresponds to the reference numeral 330, the frequency response range of the fourth pony assembly 140 corresponds to the reference numeral 340 and the frequency response range of the fifth pony assembly 150 And the frequency response range of the sixth pawn assembly 160 may correspond to the reference numeral 360 of FIG.

The first to sixth pawn assemblies 110, 120, 130, 140, 150, and 160 may have the same dynamic range as the frequency response range corresponding to the resonance frequency. For example, the range 410 of the dynamic range of the first pony assembly 110 may be between 30 dB and 100 dB, and the range of dynamic range 420 of the second pony assembly 120 may be The dynamic range range 430 of the third pawn assembly 130 may be between 50 dB and 120 dB and the dynamic range range 440 of the fourth pawn assembly 140 may be between 60 dB and 130 dB The range 450 of the dynamic range of the fifth pony assembly 150 may be between 70dB and 140dB and the range of the dynamic range 460 of the sixth pony assembly 160 may be between 80dB and 150dB.

The connection assembly 170 is connected to the microphone array 100 and the semiconductor chip 190. To this end, the connection assembly 170 includes a switch connected to each of a plurality of pawn assemblies included in the microphone array 100.

That is, each of the first to sixth switches 173, 175, 177, 179, 181 and 183 is connected to each of the first to sixth phone assemblies 110, 120, 130, 140, 150 and 160. One end of each of the first to sixth switches 173, 175, 177, 179, 181 and 183 is connected to the pad connection line 117 of each of the first to sixth phone assemblies 110, 120, 130, 140, 150, And the other end of the first to sixth switches 173, 175, 177, 179, 181, and 183 is connected to the semiconductor chip 190. [

At this time, the pad connection line 117 connects the first pads 240 of the plurality of microphones 115 included in each of the first to sixth pawn assemblies 110, 120, 130, 140, 150 and 160, The electrode connection line 119 connects the second pads 270 of the plurality of microphones 115 included in each of the first to sixth pawn assemblies 110, 120, 130, 140, 150 and 160.

The connection assembly 170 receives acoustic signals from the plurality of microphones 115 through the pad connection lines 117 and the electrode connection lines 119 and outputs the received acoustic signals to the semiconductor chip 190.

The semiconductor chip 190 is connected to the microphone array 100. That is, the semiconductor chip 190 is connected to the microphone array 100 through the connection assembly 170. The semiconductor chip 190 receives acoustic signals from the microphone array 100 through the connection assembly 170.

The semiconductor chip 190 confirms the signal amplitude of the acoustic signal received from the microphone array 100. The semiconductor chip 190 includes first to sixth switches 173, 175, 177, 179, 181, and 182 connected to the first to sixth pawn assemblies 110, 120, 130, 183 may be turned off.

The semiconductor chip 190 turns on all of the first to sixth switches 173, 175, 177, 179, 181 and 183 when the signal size of the acoustic signal is low and when the signal size of the acoustic signal starts to increase, (173).

A technique for controlling the microphone 115 in the semiconductor chip 190 will be described in more detail with reference to FIG.

5 is a flowchart illustrating a microphone control method according to an embodiment of the present invention.

Referring to FIG. 5, the semiconductor chip 190 turns on the first to sixth switches 173, 175, 177, 179, 181, and 183 included in the connection assembly 170 (S510). When sound is introduced from the outside, a plurality of microphones 115 included in the microphone array 100 are operated

The semiconductor chip 190 receives a sound signal from the microphone array 100 including the plurality of microphones 115 through the connection assembly 170 (S515). In other words, each of the plurality of microphones 115 generates a sound signal by vibrating the diaphragm 230 when an external sound is input from the outside, and outputs the sound signal to the first pad 240 and the second pad 270 175, 177, 179, 181, and 183 through the pad connection line 117 and the electrode connection line 119. The first to sixth switches 173, The first to sixth switches 173, 175, 177, 179, 181 and 183 included in the connection assembly 170 output the received acoustic signal to the semiconductor chip 190.

The semiconductor chip 190 confirms the signal amplitude of the acoustic signal received from the microphone array 100 (S520). Specifically, the semiconductor chip 190 receives acoustic signals from each of the first to sixth piano assemblies 110, 120, 130, 140, 150, 160 included in the microphone array 100, The signal size of the acoustic signal for each of the phone assemblies 110, 120, 130, 140, 150, and 160 can be confirmed.

The semiconductor chip 190 checks the set size of the microphone array 100 (S525). At this time, the set size may be set to prevent the microphone array from being damaged by the microphone array, and to minimize the noise generated from the acoustic signal. The set size may be set differently according to the frequency response range according to the resonance frequency of each of the first to sixth phone assemblies 110, 120, 130, 140, 150, That is, the semiconductor chip 190 may check the set size of each of the first to sixth phone assemblies 110, 120, 130, 140, 150, and 160.

The semiconductor chip 190 determines whether the signal magnitude of the acoustic signal received from the microphone array 100 is equal to or greater than a preset magnitude (S530). In addition, the semiconductor chip 190 may determine whether the signal size for each of the first to sixth phone assemblies 110, 120, 130, 140, 150, and 160 is equal to or greater than a predetermined size.

On the other hand, if the signal size of the acoustic signal is less than the set size, the semiconductor chip 190 may go to step S540 to determine whether the operation of the microphone array 100 is completed.

The semiconductor chip 190 turns off the switch connected to the phone assembly when the signal size of the sound signal is equal to or larger than the set size (S535). That is, the semiconductor chip 190 may turn off the switches of the first to sixth pawn assemblies 110, 120, 130, 140, 150, 160 connected to the pawn assembly whose signal size is equal to or larger than the predetermined size.

For example, the semiconductor chip 190 may identify a first signal magnitude for the acoustic signal received from the first pon assembly 110 and a first magnitude magnitude for the first pon assembly 110. The semiconductor chip 190 may turn off the first switch 173 connected to the first pone assembly 110 if the first signal size is equal to or greater than the first predetermined size.

The reason for switching off the corresponding phone assemblies when the acoustic signals are introduced into the set size or more is that the plurality of microphones 115 included in the phone assembly can be damaged by a high sound pressure and can provide a broken sound to the user This is to prevent this.

The semiconductor chip 190 determines whether the operation of the microphone array 100 is completed (S540).

If the operation of the microphone array 100 is not completed, the semiconductor chip 190 returns to step S510 so that the first to sixth switches 173, 175, 177, 179, 181, 183 can be turned on to control the microphone 115.

Thereafter, the semiconductor chip 190 completes controlling the microphone 115 when the operation of the microphone array 100 is completed.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

50: microphone system
100: microphone array
110, 120, 130, 140, 150, 160:
115: microphone
117: Pad connection line
119: electrode connection line
170: connection assembly
173, 175, 177, 179, 181, 183: switch
190: Semiconductor chip

Claims (11)

A pawn assembly including a plurality of microphones having different resonance frequencies;
A microphone array having a plurality of the pawn assemblies;
A connection assembly including a switch coupled to each of a plurality of pawn assemblies included in the microphone array; And
A semiconductor chip connected to the microphone array through the connection assembly, receiving a sound signal from the microphone array, and turning off the switch according to a signal amplitude of the sound signal;
≪ / RTI > The method according to claim 1,
The microphone
A diaphragm disposed on a substrate;
A first pad connected to the diaphragm;
A fixed electrode disposed on the diaphragm and spaced apart from the diaphragm; And
A second pad connected to the fixed electrode;
≪ / RTI > 3. The method of claim 2,
Wherein a first pad of each of a plurality of microphones included in the phone assembly is connected via a pad connection line and a second pad of each of the plurality of microphones is connected through an electrode connection line. The method of claim 3,
Wherein one side of the switch is connected to the pad connection line and the electrode connection line, and the other side of the switch is connected to the semiconductor chip. The method according to claim 1,
Wherein the plurality of microphones are arranged such that the resonance frequencies are continuous. 3. The method of claim 2,
Wherein the resonant frequency is set using a spring constant by the diaphragm and a mass of the diaphragm. The method according to claim 1,
The semiconductor chip
The signal size for each of the pawn assemblies is checked and the switch connected to the pawn assembly whose signal size is equal to or greater than a predetermined set size of the plurality of pawn assemblies is turned off. The method according to claim 1,
Wherein the microphone array is formed on a single wafer. A plurality of piano assemblies including a plurality of microphones having different resonance frequencies, a method of controlling a microphone by a semiconductor chip connected to each of the plurality of pony assemblies through a switch,
Receiving acoustic signals from the plurality of microphones;
Confirming a signal size of the acoustic signal; And
Turning off at least one of the switches connected to each of the plurality of pony assemblies according to the signal size;
/ RTI > 10. The method of claim 9,
The step of receiving acoustic signals from the plurality of microphones
And receiving acoustic signals from each of the plurality of pony assemblies. 11. The method of claim 10,
Turning off at least one of the switches connected to each of the plurality of pony assemblies
Identifying a signal magnitude of the acoustic signal for each of the plurality of pony assemblies;
Confirming a predetermined set size for each of the plurality of pony assemblies;
Determining whether a signal size for each of the plurality of pony assemblies is greater than or equal to the set size; And
Turning off a switch connected to a pawn assembly of the plurality of pawn assemblies, the signal size of which is greater than a set size;
/ RTI >

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