KR101417018B1 - Microphone and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a microphone and a method of manufacturing the same, and more particularly, to a microphone and a method of manufacturing the same, which includes a first substrate on which first and second acoustic sensors are formed; And first and second ports through which sound is input to the first and second acoustic sensors, respectively, and a second substrate bonded to the first substrate.

Therefore, the present invention is advantageous in that the acoustic sensing parts are integrally formed on a single substrate, and the uniformity and characteristic uniformity between the devices are excellent, and the performance deviation between the devices is greatly reduced.

In addition, the present invention can reduce the production cost and shorten the production period by manufacturing the microphone device by wafer level packaging (wafer level packaging) which collectively processes not only the device manufacturing but also the packaging process in the wafer state There is an advantage that the yield can be improved.

Microphone, port, substrate, adhesive, wafer, acoustic detection

Description

 [0001] Microphone and method for manufacturing same [0001]

The present invention relates to a microphone capable of making characteristics uniform and a method of manufacturing the same.

Generally, a microphone is a type of sensor that detects vibration of a sound wave or an ultrasonic wave, converts the sound into an electric signal corresponding to the vibration, and outputs the electric signal.

The microphone is used as a sound input device, and is used for a sound recorder, a telephone, a loudspeaker, a hearing aid, and the like.

Since an ordinary omni-directional microphone has the same sensitivity in all directions, it is weak against noise, so a directional microphone with high sensitivity only in certain directions has been developed.

When the direction of the directional microphone is positioned so as to face the sound source, the signal of the sound to be sensed is larger than that of the surrounding noise, so that the signal to noise ratio (SNR) can be improved.

1 is a cross-sectional view showing a schematic configuration of a conventional directional microphone, which includes a pair of ports 11 and 12 into which acoustic signals are input; A diaphragm 13 that vibrates by an acoustic signal input to the pair of ports 11 and 12; And a resistor 14 for delaying the progress time of the acoustic signal.

The conventional directional microphone thus constructed is structured such that when the acoustic signal is inputted from the front port 11 and when the acoustic signal is inputted from the rear port 12, the diaphragm 13 moves in the opposite direction.

The diaphragm 13 is connected to the rear port 12 and the front port 11. The front port 11 is connected to the front port 12 and the rear port 12, 11 by the difference of the sound pressure inputted thereto.

If the time delay of the acoustic signal by the resistor 14 is made to be the time required for the distance from the rear port 12 to the front port 11, The diaphragm 13 does not vibrate while the acoustic signals inputted through the front port 11 are canceled each other.

Although the conventional directional microphone of this type is simple in principle and structure, the uniformity in actual production is lowered, and the distance between the front port 11 and the rear port 12 and the resistance 14 are adjusted very precisely And the directivity characteristic of frequency is different according to the frequency characteristic of the resistance of the acoustic signal. Therefore, unlike the omnidirectional microphone, the damping of the diaphragm is small, so that it is sensitive to acoustic signals as well as other vibrations.

The present invention solves the problem that the characteristics can not be made uniform.

According to a first aspect of the present invention,

A first substrate on which first and second acoustic sensing portions are formed;

A first and a second port through which sound is input to the first and second acoustic sensing units, respectively, and a second substrate bonded to the first substrate.

According to a second preferred aspect of the present invention,

Forming first and second acoustical sensing portions on a first substrate;

Forming first and second ports through which sound is input to each of the first and second acoustical sensing units on the second substrate;

Aligning the first and second substrates so that sound can be input to the first and second ports from the first and second ports, respectively, and bonding the second substrate to the first substrate; A manufacturing method is provided.

According to a third aspect of the present invention,

A method of manufacturing a semiconductor device, comprising: forming a plurality of acoustic cells each composed of a first and a second acoustic sensor on a semiconductor wafer;

Forming a plurality of acoustic input cells on the packaging wafer, the acoustic input cells each having a first port and a second port, the first and second acoustic sensors corresponding to the first and second acoustic sensors, respectively;

Connecting the first and second ports of the acoustic input cells to the first and second acoustic sensing units of the plurality of acoustic cells to bond the packaging wafers to the top of the semiconductor wafers;

And dividing the microphone into single microphones constituted by one acoustic input cell bonded on the one acoustic cell.

The present invention has the effect of forming the acoustic sensing parts integrally on a single substrate, and having excellent uniformity and characteristic uniformity among the respective devices, thereby significantly reducing the performance deviation between the devices.

In addition, the present invention can reduce the production cost and shorten the production period by manufacturing the microphone device by wafer level packaging (wafer level packaging) which collectively processes not only the device manufacturing but also the packaging process in the wafer state And the yield can be improved.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

2A and 2B are conceptual cross-sectional views illustrating a microphone according to the present invention. As shown in FIG. 2A, first and second acoustic sensors 110 and 120 are formed on a first substrate 100.

The second substrate 200 is bonded to the first substrate 100 and the first and second ports 200 and 210 are connected to the first and second acoustic sensors 110 and 120, (210, 220) are formed.

The first and second acoustic sensors 110 and 120 are preferably acoustic sensors that sense sound in one of electrostatic capacitance, piezoelectric, piezo resistive, electret, and magnetic .

The first and second acoustic sensors 110 and 120 may be fabricated by a micro electro mechanical system (MEMS) process on the first substrate 100.

Thus, when the acoustic sensing parts are integrally formed on one substrate, the uniformity and characteristic uniformity between the devices are excellent, and the performance deviation between the devices is greatly reduced.

Particularly, in order to construct a directional microphone, it is advantageous that the performance deviation between the respective microphone elements is small. Therefore, the structure of the microphone according to the present invention has an advantage that a directional microphone with excellent performance can be easily manufactured.

3A and 3B are conceptual perspective views illustrating a microphone according to the present invention. As shown in FIG. 3A, a first substrate 100 on which first and second acoustic sensing units 110 and 120 are formed, And a second substrate 200 having first and second ports 210 and 220 through which sound is input corresponding to the units 110 and 120, respectively.

At this time, the first substrate 100 is preferably formed of a silicon substrate.

The second substrate 200 may be one of a glass substrate, a silicon substrate, and a sintered ceramic substrate which is easily joined to the first substrate 100.

The first and second ports 210 and 220 of the second substrate 200 are manufactured using a micromachining process such as photolithography, dry etching, and wet etching.

Therefore, it is possible to precisely manufacture the distance between the sound input ports, the deviation between the processes, and the deviation in performance between the individual devices, compared to a microphone formed by a conventional technique such as machining and assembly.

Thereafter, the first and second substrates 100 and 200 are aligned so that sound can be input to the first and second sound sensing units 110 and 120 from the first and second ports 210 and 220, 100 are bonded to the second substrate 200, a microphone according to the present invention as shown in FIG. 3B is manufactured.

4A and 4B are a perspective view and a cross-sectional view, respectively, illustrating the shape of a second substrate according to the first embodiment of the present invention, in which an input portion 211 of a first port 210 is formed on one side of a second substrate 200 And an input unit 221 of the second port 220 is formed on the other side of the second substrate 200.

Therefore, the second substrate 200 according to the first embodiment of the present invention has a structure in which input portions of the first and second ports 210 and 220 are formed on both sides.

3A and 4A, the first port 210 formed on the second substrate 200 is connected to the first sound sensing unit 110 of the first substrate 100, A portion 212; And a first input unit 211 connected to the first communication unit 212 and receiving sound from an external sound source and formed on one side of the second substrate 200.

The second port 220 formed on the second substrate 200 includes a second communication unit 222 through which sound is input to the second sound sensing unit 120 of the first substrate 100; And a second input unit 221 connected to the second communication unit 222 and receiving sound from an external sound source and formed on the other side of the second substrate 200.

5A and 5B are a perspective view and a cross-sectional view illustrating the shape of a second substrate according to a second embodiment of the present invention. An input portion 231 of a first port 230 is formed on an upper surface of a second substrate 200 And an input portion 241 of the second port 240 is formed on the other surface of the second substrate 200.

As a result, the second substrate 200 according to the second embodiment of the present invention has a structure in which input portions of the first and second ports 230 and 240 are formed on the upper surface.

3A and 5A, the first port 230 formed on the second substrate 200 is connected to the second substrate 200 through the second substrate 200, One communicating portion 232; And a first input unit 231 communicating with the first communication unit 232 to receive sound from an external sound source and formed on one surface of the upper surface of the second substrate 200.

The second port 240 formed on the second substrate 200 includes a second communication portion 242 through which sound is input to the second sound sensing portion 120 of the first substrate 100; And a second input unit 241 connected to the second communication unit 242 and receiving sound from an external sound source and formed on the other surface of the second substrate 200.

6A to 6C are schematic cross-sectional views for explaining a method of packaging an acoustic signal processing unit in a microphone according to the present invention. As shown in FIG. 6A, the first and second acoustic sensing units are formed on independent substrates 310 and 330, respectively.

An acoustic signal processing unit for processing the sounds inputted to the first and second acoustic sound sensing units in a directional or non-directional manner and outputting them is formed on a separate substrate 320.

Thereafter, as shown in FIG. 6B, between the substrate 310 on which the first sound sensing part is formed and the substrate 330 on which the second sound sensing part is formed, .

Subsequently, the second substrate 350 having the first and second ports formed thereon is bonded to the first and second acoustic sensing parts and the boards 310, 320, and 330 formed with the acoustic signal processing part, thereby manufacturing a microphone as shown in FIG. 6C .

The acoustic signal processor is a processor for processing the acoustic signals sensed by the first and second acoustic sensors.

The acoustic signal processing unit may include an acoustic signal processing unit for processing acoustic signals sensed to have high sensitivity in a specific direction or an acoustic signal processing unit for processing acoustic signals sensed in an omnidirectional manner so as to have the same sensitivity in all directions .

7 is a schematic perspective view illustrating a microphone having an acoustic signal processing unit according to the present invention. Referring to FIG. 7, a first sound sensing unit 510 is formed on one side of a single substrate 500, And a sound signal processing unit 520 is formed between the first and second sound sensing units 510 and 530.

That is, the first and second acoustic sensing units 510 and 530 and the acoustic signal processing unit 520 are integrally formed on a single substrate 500.

8A to 8C are conceptual plan views illustrating a method of forming a microphone at a wafer level according to an embodiment of the present invention. First, the acoustic cell 610 having the first and second acoustic sensing units on the semiconductor wafer 600 ) (Fig. 8A)

Next, a plurality of acoustic input cells 710 having first and second ports for receiving sounds corresponding to the first and second acoustic sensing units are formed on the packaging wafer 700 (Fig. 8B)

Subsequently, the first and second ports of the acoustic input cell 710 are associated with the first and second acoustic sensing units of the plurality of acoustic cells 610, and the packaging wafer 700 is placed on the semiconductor wafer 600, (Fig. 8C)

Here, as shown in FIG. 8C, one acoustic input cell 710 bonded onto the one acoustic cell 610 becomes a single microphone.

And then separates into single microphones consisting of one acoustic input cell bonded onto the one acoustic cell.

Such a single microphone is separated by dicing the packaging wafer and the semiconductor wafer.

According to the above-described process, since the present invention can be manufactured by wafer level packaging (WLP) in which individual elements in a packaged state can be obtained, it is possible to improve the uniformity of performance between elements, And it is suitable for mass production.

9A and 9B are schematic cross-sectional views illustrating a first substrate on which an acoustic sensing unit is formed according to the present invention, wherein the acoustic sensing unit of FIG. 9A is capable of sensing sound by capacitance, and the acoustic sensing unit of FIG. 9B is a piezoelectric capacitance It is possible to sense sound by piezoresistive.

FIG. 9A shows a state in which one of the first and second acoustic sensing units formed on the first substrate is formed. FIG.

Therefore, each of the first and second acoustical sensing units includes a groove 801 formed in a lower portion of the first substrate 800; A first electrode 810 formed on the first substrate 800; A spacer 820 formed on the first electrode 810 and forming a space 860 on the inner side; And a second electrode 830 formed on the spacer 820 to seal the space 860. The second electrode 830 penetrates from the first substrate 800 region above the groove 801 to the first electrode 810, A plurality of through holes 850 through which the acoustic signal can flow into the space 860 or a plurality of through holes 830 through which the second electrode 830 penetrates and into which the acoustic signal can flow, Holes 850 are formed.

Here, the first electrode 810 or the second electrode 830 may be an electret injected with a charge.

The first electrode 810 or the second electrode 830 may be formed of polysilicon doped with a metal or a carrier.

The plurality of through holes 850 are vent holes through which air can flow.

FIG. 9B shows a state in which one of the first and second acoustic sensing units formed on the first substrate is formed.

Accordingly, each of the first and second acoustic sensors includes a through hole 910 formed in a lower portion of the first substrate 900; A membrane film (920) formed on the first substrate (900) and exposed to the through hole (910); And a piezoelectric capacitor 930 on the membrane film 920.

The piezoelectric capacitor 930 is formed by stacking one electrode 931, a piezoelectric film 932, and a previous electrode 933.

When the acoustic signal is inputted to the acoustic sensing unit, the membrane membrane 920 is deformed and the piezoelectric capacitor 930 senses the deformation of the membrane membrane 920 as a capacitance value.

In the meantime, the present invention can also be implemented by a structure in which the sound sensing unit converts a deformation of the membrane membrane 920 into an electrical signal by a piezoresistor integrated in a predetermined region of the membrane membrane 920.

As described above, according to the present invention, by manufacturing the microphone array by applying the MEMS technique, it is possible to precisely and precisely manufacture the performance deviation and the separation distance between the microphone devices, which are important characteristics in implementing the directional microphone.

Also, there is an advantage in that the directivity can be realized by using a plurality of omnidirectional microphones, but the size can be reduced.

In addition, wafer-level packaging (wafer level packaging) that treats not only devices but also packaging processes in a wafer state can be expected to reduce the production cost, shorten the production period, and improve the yield of the microphone devices by batch processing the semiconductor.

In addition, the present invention can be extended to two or more microphone arrays, and can be easily applied to a voice input device for beam forming or the like capable of adjusting the sensitivity according to the input direction of sound.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

1 is a cross-sectional view showing a schematic configuration of a conventional directional microphone

2A and 2B are conceptual cross-sectional views for explaining a microphone according to the present invention

3A and 3B are conceptual perspective views illustrating a microphone according to the present invention.

4A and 4B are a perspective view and a cross-sectional view showing the shape of the second substrate according to the first embodiment of the present invention

5A and 5B are a perspective view and a cross-sectional view illustrating the shape of a second substrate according to a second embodiment of the present invention

6A to 6C are schematic cross-sectional views for explaining a method of packaging an acoustic signal processing unit in a microphone according to the present invention

7 is a schematic perspective view illustrating a microphone having an acoustic signal processing unit according to the present invention.

8A to 8C are conceptual plan views illustrating a method of forming a microphone at a wafer level according to the present invention.

9A and 9B are schematic cross-sectional views illustrating a first substrate on which an acoustically sensitive portion is formed according to the present invention

Claims (13)

A first substrate on which first and second acoustic sensing portions are formed; And And a second substrate having first and second ports through which sound is input to the first and second acoustic sensing units, respectively, and bonded to the first substrate, A first port formed on the second substrate, A first communication unit for receiving sound into the first sound sensing unit of the first substrate; And And a first input unit communicating with the first communication unit to receive sound from an external sound source and formed on one side or an upper side of the second substrate, And a second port formed on the second substrate, A second communication unit to which sound is input to the second sound sensing unit of the first substrate; And And a second input connected to the second communication unit to receive sound from an external sound source and formed on the other surface or the other surface of the second substrate. The method according to claim 1, Wherein the first and second acoustic sensing units comprise: Wherein the microcomputer is an acoustic sensor for sensing sound in one of a capacitance, a piezoelectric, a piezoresistive, an electret, and a magnetic. The method according to claim 1, Between the first and second acoustic sensing units, And an acoustic signal processor for processing acoustic signals sensed by the first and second acoustic sensors. The method of claim 3, Wherein the acoustic signal processor comprises: Wherein the acoustic signal processing unit processes an acoustic signal detected as a directivity so that the sensitivity is high in a specific direction. The method of claim 3, Wherein the acoustic signal processor comprises: Wherein the acoustic signal processing unit processes the acoustic signal sensed as omni-directional so that the sensitivity is the same in all directions. delete The method according to claim 1, Wherein the first substrate comprises: Silicon substrate, The second substrate may include: A glass substrate, a silicon substrate, and a sintered ceramic substrate. The method according to claim 1 or 3, Wherein each of the first and second acoustic sensors comprises: A groove formed in the lower portion of the first substrate; A first electrode formed on the first substrate; A spacer formed on the first electrode to form a space inside; And a second electrode formed on the spacer to seal the space, A plurality of through holes through which a sound signal can flow from the first substrate region above the groove to the first electrode or through which the acoustic signal can flow, And a plurality of through-holes are formed in the housing. The method of claim 8, Wherein the first electrode or the second electrode comprises: Characterized in that the microphone is an electron injected with a charge. The method according to claim 1 or 3, Wherein each of the first and second acoustic sensors comprises: A through hole formed in the lower portion of the first substrate; A membrane film formed on the first substrate and exposed to the through-hole; And a piezoelectric capacitor is formed on the membrane layer. Forming first and second acoustical sensing portions on a first substrate; Forming first and second ports through which sound is input to each of the first and second acoustical sensing units on the second substrate; Aligning the first and second substrates so that sound can be input to the first and second ports from the first and second ports, respectively, and bonding the second substrate to the first substrate; Gt; A method of manufacturing a semiconductor device, comprising: forming a plurality of acoustic cells each composed of a first and a second acoustic sensor on a semiconductor wafer; Forming a plurality of acoustic input cells on the packaging wafer, the acoustic input cells each having a first port and a second port, the first and second acoustic sensors corresponding to the first and second acoustic sensors, respectively; Connecting the first and second ports of the acoustic input cells to the first and second acoustic sensing units of the plurality of acoustic cells to bond the packaging wafers to the top of the semiconductor wafers; And separating the plurality of acoustic cells and acoustic input cells into single microphones having one acoustic cell and one acoustic input cell. The method of claim 12, Wherein the first and second acoustic sensing units comprise: Wherein the semiconductor wafer is formed by a MEMS (Micro Electro Mechanical Systems) process.

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