KR20190070618A - Mems microphone - Google Patents

Abstract

A MEMS microphone capable of reducing the volume by allowing an integrated circuit electrically connected to an MEMS acoustic sensor to be embedded in a substrate is provided.
The MEMS microphone includes a substrate, a MEMS acoustic sensor provided at an upper portion of the substrate to sense sound, an integrated circuit embedded in the substrate, electrically connected to the MEMS acoustic sensor, and a MEMS acoustic sensor And a case having an acoustic hole into which sound is introduced at a position corresponding to the MEMS acoustic sensor.

Description

MEMS MICROPHONE

The present invention relates to a MEMS microphone capable of reducing the volume.

2. Description of the Related Art Generally, a microphone is a device that converts voice into an electrical signal. Recently, the microphone has been getting smaller and smaller, and a microphone using MEMS (Micro Electro Mechanical System) technology is being developed.

The MEMS microphone is more resistant to moisture and heat than the Electret Condenser Microphone (ECM), and has the advantage of miniaturization.

The MEMS microphone is applied to various communication devices including a mobile communication device such as a smart phone, an earphone and a hearing aid, and can be classified into a capacitive type and a piezoelectric type.

The MEMS microphone of the capacitive type is composed of a fixed membrane and a diaphragm, and when the acoustic is introduced into the diaphragm from the outside, the distance between the fixed membrane and the diaphragm changes and the capacitance value accordingly changes.

At this time, the sound pressure can be measured by the generated electric signal.

Piezoelectric MEMS microphones consist of only a diaphragm, and when the diaphragm is deformed by sound from the outside, an electric signal is generated by the piezoelectric effect and the sound pressure is measured.

The MEMS microphone may include an MEMS acoustic sensor that senses sound and an integrated circuit that is electrically coupled to the MEMS acoustic sensor to receive the signal.

The MEMS acoustic sensor and the integrated circuit are provided on the substrate and can be electrically connected by wire bonding.

Since the MEMS acoustic sensor and the integrated circuit are provided on the substrate, the volume occupied by the substrate is so large that the MEMS microphone is bulky as a whole.

Further, since the MEMS acoustic sensor and the integrated circuit are electrically connected by wire bonding, the MEMS microphone has to be bulky as a whole due to the height of the wire bonding.

According to an aspect of the present invention, there is provided a MEMS microphone in which an integrated circuit electrically connected to a MEMS acoustic sensor is embedded in a substrate to reduce the volume.

A MEMS microphone according to an embodiment of the present invention includes a substrate, a MEMS acoustic sensor provided on the substrate to sense sound, an integrated circuit embedded in the substrate, electrically connected to the MEMS acoustic sensor, And a case having an acoustic hole for receiving the MEMS acoustic sensor at a position corresponding to the MEMS acoustic sensor.

The substrate may include a first metal layer bonded to the integrated circuit such that the integrated circuit is electrically connected, a second metal layer spaced apart from the first metal layer, and a core filled between the first metal layer and the second metal layer. have.

A pattern may be formed on the first metal layer and the second metal layer.

The first metal layer and the second metal layer may be electrically connected by a metal layer connection via hole passing through the core.

Wherein the MEMS acoustic sensor comprises: a diaphragm that vibrates by sound introduced into the acoustic hole; a support for supporting the diaphragm above the substrate; a first electrode provided on an upper surface of the diaphragm; A first via hole electrically connecting the first electrode and the first metal layer to the first electrode through the support portion; and a second via hole electrically connecting the second electrode and the first metal layer, And a second via hole.

The integrated circuit may be embedded in the core, and may be provided at a position corresponding to the vertical direction of the MEMS acoustic sensor.

According to another aspect of the present invention, there is provided a MEMS microphone comprising: a substrate having an acoustic hole into which sound is introduced; a MEMS acoustic sensor provided on the substrate to sense sound; An integrated circuit electrically connected thereto, and a case provided on the substrate to receive the MEMS acoustic sensor.

The acoustic holes may be provided at positions corresponding to the MEMS acoustic sensors, and the integrated circuit may be provided at positions corresponding to portions of the MEMS acoustic sensors in the vertical direction so as to avoid the acoustic holes.

The acoustic hole may be provided at a position corresponding to the MEMS acoustic sensor, and the integrated circuit may include a through hole provided at a position corresponding to the MEMS acoustical sensor in the vertical direction and corresponding to the acoustic hole. have.

According to another aspect of the present invention, there is provided a MEMS microphone, comprising: a substrate having a first acoustic hole through which sound is introduced; a MEMS acoustic sensor provided at an upper portion of the substrate for sensing sound; An integrated circuit electrically connected to the sensor, and a case provided on the substrate, the case having a second acoustic hole for receiving the MEMS acoustic sensor and having a sound inlet at a position corresponding to the MEMS acoustic sensor.

The integrated circuit may include a through hole provided at a position corresponding to the vertical direction of the MEMS acoustic sensor and corresponding to the first acoustic hole.

An acoustic delay filter may be provided in the second acoustic hole so that only the sound flowing into the first acoustic hole is transmitted to the MEMS acoustic sensor.

According to the embodiments of the present invention, it is possible to reduce the volume of the MEMS microphone and downsize it.

1 is a schematic diagram of a MEMS microphone according to an embodiment of the present invention;
2 is a schematic view illustrating an integrated circuit bonded to a first metal layer of a substrate according to an embodiment of the present invention;
FIG. 3 is a view schematically showing a state in which a core and a second metal layer are formed in FIG. 2; FIG.
FIG. 4 is a schematic view illustrating a pattern formed in the first metal layer and the second metal layer in FIG. 3, and connecting a first metal layer and a second metal layer by a metal layer connection via hole;
FIG. 5 is a view schematically showing a state where the first metal layer is inverted in FIG. 4 so as to be positioned on the second metal layer; FIG.
6 is a view schematically showing a state in which the MEMS acoustic sensor is electrically connected to the first metal layer in FIG.
FIG. 7 is a view schematically showing a case in which an upper part of a substrate is provided in FIG. 6; FIG.
8 is a schematic view of a MEMS microphone in which acoustic holes are formed in a substrate according to another embodiment of the present invention.
9 is a schematic view of a MEMS microphone in which acoustic holes are formed in a substrate according to another embodiment of the present invention, and a through hole is formed in the integrated circuit.
10 is a schematic view of a MEMS microphone in which a first acoustic hole and a second acoustic hole are formed in a substrate and a case, respectively, according to another embodiment of the present invention.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory only and are not restrictive of the invention, as claimed, and it is to be understood that the invention is not limited to the disclosed embodiments.

In addition, the same reference numerals or signs shown in the respective figures of the present specification indicate components or components performing substantially the same function.

Also, the terms used herein are used to illustrate the embodiments and are not intended to limit and / or limit the disclosed invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more features, integers, steps, operations, elements, components, or combinations thereof.

It is also to be understood that terms including ordinals such as " first ", "second ", and the like used herein may be used to describe various elements, but the elements are not limited by the terms, It is used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

The term "front end", "rear end", "upper", "lower", "upper" and "lower end" used in the following description are defined with reference to the drawings, And the position is not limited.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of a MEMS microphone according to an embodiment of the present invention.

1, the MEMS microphone includes a substrate 10, a MEMS acoustic sensor 20 provided at an upper portion of the substrate 10 to sense sound flowing from the outside, a MEMS acoustic sensor 20 electrically connected to the MEMS acoustic sensor 20, An integrated circuit 30 to be connected and a case 40 provided to receive the MEMS acoustic sensor 20 on the top of the substrate 10.

The substrate 10 includes a first metal layer 11 bonded to the integrated circuit 30 so as to be electrically connected to the first metal layer 11 and a second metal layer 13 spaced apart from the first metal layer 11, And a core 15 filled between the first metal layer 13 and the second metal layer 13.

A pattern may be formed in the first metal layer 11 and the second metal layer 13 through an etching process in which a specific portion is selectively scraped to engrave an electronic circuit.

The patterned first metal layer 11 and the second metal layer 13 may be electrically connected by a metal layer connection via hole 17. [

The core 15 filled between the first metal layer 11 and the second metal layer 13 may be an epoxy resin FR4 and the core 15 may be embedded with the integrated circuit 30. [ .

The MEMS acoustic sensor 20 is provided on the substrate 10 and can sense sound flowing from the outside.

The MEMS acoustic sensor 20 includes a diaphragm 21 which is vibrated by sound introduced into an acoustic hole 41 provided in a case 40 to be described later, A first electrode 23 provided on the upper surface of the vibration film 21; a second electrode 24 provided on the lower surface of the vibration film 21; A first via hole 25 for electrically connecting the first electrode 23 to the first metal layer 11 of the substrate 10 and a second via hole 25 penetrating the support portion 22 to connect the second electrode 24 and the first metal layer 11 And a second via hole 26 electrically connecting the first via hole 26 and the second via hole 26.

In the figure, the MEMS acoustic sensor 20 comprises only the diaphragm 21, and when the diaphragm 21 is deformed by the sound introduced from the outside, an electrical signal is generated by a piezoelectric effect to measure the sound pressure A piezoelectric type MEMS microphone is shown and described as a piezoelectric type MEMS microphone.

However, the present invention is not limited to this, and the MEMS acoustic sensor is composed of a diaphragm and a fixed membrane. When external sound is introduced into the diaphragm, the distance between the fixed membrane and the diaphragm changes, A capacitive type MEMS microphone for measuring a sound pressure by an electrical signal.

The MEMS acoustic sensor 20 is provided at a position corresponding to the acoustic hole 41 provided in the case 40 and can sense the sound flowing into the acoustic hole 41.

The diaphragm 21 can be deformed in a space formed between the diaphragm 21 and the substrate 10 by the sound introduced through the acoustic hole 41. [

The first electrode 23 provided on the upper surface of the diaphragm 21 and the second electrode 24 provided on the lower surface of the diaphragm 21 are connected to a first via hole 25 And the second via hole 26. The first metal layer 11 may be connected to the first metal layer 11 of the substrate 10. [

Since the first electrode 23 and the second electrode 24 are electrically connected to the first metal layer 11 of the substrate 10 and the first metal layer 11 is electrically connected to the integrated circuit 30, A signal generated when the diaphragm 21 is deformed by the sound can be transmitted to the integrated circuit 30. [

The integrated circuit 30 may be an application specific integrated circuit (ASIC).

The integrated circuit 30 is electrically connected to the first electrode 23 and the second electrode 24 provided in the MEMS acoustic sensor 20 and when the diaphragm 21 is deformed by sound introduced from the outside The sound pressure can be measured by the generated electrical signal.

The integrated circuit 30 may be embedded in the core 15 inside the substrate 10 and underneath the MEMS acoustic sensor 20 at a position vertically corresponding to the MEMS acoustic sensor 20.

Since the integrated circuit 30 is electrically connected directly to the first metal layer 11 of the substrate 10, it may be advantageous for heat transfer.

Since the integrated circuit 30 is buried in the substrate 10 and the integrated circuit 30 and the MEMS acoustic sensor 20 are connected by the metal layer connection via hole 17 without wire bonding, the overall volume of the MEMS microphone Can be reduced.

The case 40 is provided to receive the MEMS acoustic sensor 20 at the upper portion of the substrate 10 and may include an acoustic hole 41 through which sound is introduced from the outside at a position corresponding to the MEMS acoustic sensor 20. [ have.

Next, a method of manufacturing a MEMS microphone will be described with reference to FIGS. 2 to 7. FIG.

FIG. 2 is a view schematically showing a state in which an integrated circuit is bonded to a first metal layer of a substrate according to an embodiment of the present invention. FIG. 3 is a view schematically showing a state where a core and a second metal layer are formed FIG. 4 is a view schematically illustrating a state in which a first metal layer and a second metal layer are patterned in FIG. 3, and a first metal layer and a second metal layer are connected by a metal layer connection via hole. FIG. 6 is a schematic view illustrating a state in which the MEMS acoustic sensor is electrically connected to the first metal layer in FIG. 5, and FIG. 6 is a cross- 7 is a view schematically showing a case in which a case is provided on an upper portion of the substrate in FIG.

2, after the bonding agent G is applied to the first metal layer 11 forming the substrate 10, the integrated circuit 30 can be flip-chip bonded to the first metal layer 11 have.

Since the integrated circuit 30 is directly bonded to the first metal layer 11 by flip chip bonding, it may be advantageous for heat transfer.

When the integrated circuit 30 is bonded to the first metal layer 11, the core 15 is filled on the first metal layer 11 and the second metal layer 13 So that the integrated circuit 30 can be embedded in the substrate 10.

After forming the second metal layer 13 on the core 15, a pattern is formed on the first metal layer 11 and the second metal layer 13 as shown in FIG. 4, The first metal layer 11 and the second metal layer 13 can be electrically connected by the metal layer connection via hole 17. [

The first metal layer 11 and the second metal layer 13 are electrically connected to each other so that the first metal layer 11 is positioned on the second metal layer 13, You can turn it over.

6, the MEMS acoustic sensor 20 is provided on the first metal layer 11 so that the MEMS acoustic sensor 20 and the first metal layer 11 are electrically connected to each other .

After the MEMS acoustic sensor 20 and the first metal layer 11 are electrically connected to each other, the case 40 may be provided on the substrate 10 as shown in FIG.

Next, another embodiment of the MEMS microphone will be described with reference to FIGS. 8 to 10. FIG.

FIG. 8 is a schematic view of a MEMS microphone in which acoustic holes are formed in a substrate according to another embodiment of the present invention. FIG. 9 is a perspective view of a MEMS microphone in which acoustic holes are formed in a substrate according to another embodiment of the present invention, 10 is a schematic view of a MEMS microphone in which a first acoustic hole and a second acoustic hole are formed in a substrate and a case according to another embodiment of the present invention, respectively.

As shown in FIG. 8, the MEMS microphone may be configured such that the acoustic hole 18 is formed in the substrate 10, not in the case 40.

When the acoustic hole 18 is formed on the substrate 10, the MEMS acoustic sensor 20 can be provided at a position corresponding to the acoustic hole 18 in the same manner as the MEMS microphone shown in FIG.

Since the acoustic holes 18 are formed in the substrate 10, the integrated circuit 30 can be provided at a position corresponding to a part of the integrated circuit 30 in the vertical direction with respect to the MEMS acoustic sensor 20, so as to avoid the acoustic holes 18. [

1 except that the first via hole 25 connecting the first electrode 23 to the first metal layer 11 and the second electrode 24 are connected to the first metal layer 11 through the first metal layer 11. In this case, Only the position of the second via hole 26 connecting to the metal layer 11 may be different.

As shown in Fig. 9, the integrated circuit 30 may be provided at a position vertically corresponding to the MEMS acoustic sensor 20 like the MEMS microphone shown in Fig. 1, in which case the integrated circuit 30 The through hole 31 may be formed at a position corresponding to the acoustic hole 18 of the diaphragm 21 so that the sound introduced through the acoustic hole 18 can be transmitted to the diaphragm 21.

As shown in FIG. 10, the MEMS microphone may have a first acoustic hole 19 and a second acoustic hole 43 formed in the substrate 10 and the case 40, respectively.

When the first acoustic hole 19 and the second acoustic hole 43 are formed in the substrate 10 and the case 40 respectively, the integrated circuit 30 is positioned at a position vertically corresponding to the MEMS acoustic sensor 20 So that the sound introduced through the first acoustic hole 19 can be transmitted to the diaphragm 21 at a position corresponding to the first acoustic hole 19 of the integrated circuit 30. [ A through hole 33 may be formed.

At this time, the directional MEMS microphone can be constituted by providing the acoustic delay filter 50 in the second acoustic hole 43 so that only the sound flowing into the first acoustic hole 19 is transmitted to the MEMS acoustic sensor 20.

While the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. .

10: substrate 11: first metal layer
13: second metal layer 15: core
17: metal layer connection via hole 18: acoustic hole
19: 1st sound hole
20: MEMS acoustic sensor 21: diaphragm
22: Support part 23: First electrode
24: second electrode 25: first via hole
26: Second via hole
30: integrated circuit 31, 33: through hole
40: Case 41: Acoustic hole
50: Acoustic delay filter
G: Bonding agent

Claims (12)

Board;
A MEMS acoustic sensor provided on the substrate to sense sound;
An integrated circuit embedded in the substrate and electrically connected to the MEMS acoustic sensor; And
A case having an acoustic hole through which sound is introduced at a position corresponding to the MEMS acoustic sensor, the case being provided on the substrate to receive the MEMS acoustic sensor;
. The method according to claim 1,
Wherein the substrate comprises a first metal layer bonded to the integrated circuit so as to be electrically connected, a second metal layer spaced apart from the first metal layer, and a core filled between the first metal layer and the second metal layer, microphone. 3. The method of claim 2,
Wherein a pattern is formed on the first metal layer and the second metal layer. The method of claim 3,
Wherein the first metal layer and the second metal layer are electrically connected by a metal layer connection via hole passing through the core. 5. The method of claim 4,
Wherein the MEMS acoustic sensor comprises: a diaphragm that vibrates by sound introduced into the acoustic hole; a support for supporting the diaphragm above the substrate; a first electrode provided on an upper surface of the diaphragm; A first via hole electrically connecting the first electrode and the first metal layer to the first electrode through the support portion; and a second via hole electrically connecting the second electrode and the first metal layer, A MEMS microphone comprising a second via hole. 6. The method of claim 5,
Wherein the integrated circuit is embedded in the core and is provided at a position corresponding to a vertical direction with respect to the MEMS acoustic sensor. A substrate having an acoustic hole into which sound is introduced;
A MEMS acoustic sensor provided on the substrate to sense sound;
An integrated circuit embedded in the substrate and electrically connected to the MEMS acoustic sensor; And
A case provided on the substrate to receive the MEMS acoustic sensor;
. 8. The method of claim 7,
Wherein the acoustic hole is provided at a position corresponding to the MEMS acoustic sensor, and the integrated circuit is provided only at a portion corresponding to the MEMS acoustic sensor in a vertical direction so as to avoid the acoustic hole. 8. The method of claim 7,
Wherein the acoustic hole is provided at a position corresponding to the MEMS acoustic sensor and the integrated circuit includes a through hole provided at a position corresponding to the acoustic hole in a direction perpendicular to the MEMS acoustic sensor, microphone. A substrate having a first acoustic hole through which sound is introduced;
A MEMS acoustic sensor provided on the substrate to sense sound;
An integrated circuit embedded in the substrate and electrically connected to the MEMS acoustic sensor; And
A case having a second acoustic hole for receiving the MEMS acoustic sensor at an upper portion of the substrate, the second acoustic hole for receiving sound at a position corresponding to the MEMS acoustic sensor;
. 11. The method of claim 10,
Wherein the integrated circuit includes a through hole provided at a position corresponding to a vertical direction of the MEMS acoustical sensor and corresponding to the first acoustic hole. 12. The method of claim 11,
Wherein the second acoustic hole is provided with an acoustic delay filter so that only the sound flowing into the first acoustic hole is transmitted to the MEMS acoustic sensor.

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