close

Вход

Забыли?

вход по аккаунту

JP2011124748

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2011124748
An object of the present invention is to provide a differential type microphone unit which can be
efficiently assembled and which can be easily miniaturized. A microphone unit 1 includes an
electro-acoustic conversion unit 40 having a diaphragm 42 and converting a sound signal into an
electric signal, and the electro-acoustic conversion unit 40 in a storage space 62. It comprises a
housing 60 in which an opening (a first through hole 21) to be closed is formed, and a mounting
member 10 for mounting the housing 60 in a first recess. A lower space 65 communicating with
the opening 21 is formed on the lower side of the electroacoustic transducer 40, and a first space
61 for guiding an external sound from the upper side to the lower space 65 and a second space
for guiding an external sound to the accommodation space 62 A (second through hole) 31 is
formed. The first space 61 is formed using a space formed between the side wall of the first
recess in which the first groove 12 is formed and the outer wall of the housing 60. [Selected
figure] Figure 3
マイクロホンユニット
[0001]
The present invention relates to a microphone unit having a function of converting an input
sound into an electric signal and outputting the electric signal.
[0002]
Conventionally, for example, a microphone unit is applied to a voice input device such as a voice
communication device such as a cellular phone or transceiver, or an information processing
03-05-2019
1
system using a technology for analyzing input voice such as a voice authentication system, or a
recording device. There is.
In recent years, miniaturization of electronic devices has progressed, and miniaturization and
thinning of a microphone unit applied to a voice input device are also desired, and development
of such a microphone unit has been conventionally performed (for example, Patent Document 1)
reference).
[0003]
The microphone unit disclosed in Patent Document 1 has a configuration in which a plurality of
intermediate members are disposed separately from the substrate in the case formed of the front
housing and the rear housing, the number of parts is large, and the assembly operation is not
always necessary. Not easy. Therefore, it is determined that the microphone unit disclosed in
Patent Document 1 has room for improvement.
[0004]
Further, it is desirable that the microphone unit applied to the above-described voice input device
can accurately extract a target voice and can remove noise (background noise and the like) other
than the target voice. In consideration of such a point, for example, Patent Document 2 discloses
a differential microphone unit configured using one diaphragm.
[0005]
In the differential type microphone unit disclosed in Patent Document 2, the user's voice
generated near the microphone unit and incident on both sides of the diaphragm has a large
sound pressure difference between one side and the other side of the diaphragm. It produces and
vibrates a diaphragm. On the other hand, noises incident on both sides of the diaphragm from a
distance are almost the same sound pressure, cancel each other, and hardly vibrate the
diaphragm. For this reason, the sound pressure for vibrating the diaphragm can be regarded as
the sound pressure indicative of the user's voice, and the electrical signal acquired based on the
vibration of the diaphragm has the noise removed and the electricity indicative of the user's
voice. It can be considered as a signal.
03-05-2019
2
[0006]
JP, 2005-295278, A JP, 2008-258904, A
[0007]
By the way, the present applicants are developing a microphone unit as shown in FIG. 19 and
FIG. 20 as a differential type microphone unit provided so as to be surface mountable.
FIG. 19 is an exploded perspective view showing the configuration of the microphone unit
previously developed by the present applicants. FIG. 20 is a schematic cross-sectional view
showing the configuration of a microphone unit previously developed by the present applicants.
Hereinafter, the microphone unit shown in FIG. 19 and FIG. 20 will be expressed as a microphone
unit of prior development.
[0008]
As shown in FIGS. 19 and 20, the microphone unit 100 of the prior development includes a boxshaped bottom case 101, a microphone (Micro Electro Mechanical System) chip 111 and an
Application Specific Integrated Circuit (ASIC) 112. A substrate 102 and a top case 103 disposed
to cover the microphone substrate 102 are provided.
[0009]
The MEMS chip 111 is a microphone chip manufactured using a semiconductor manufacturing
technology, and has a function of converting a sound signal into an electric signal, having a
diaphragm 113 which is displaced by sound pressure.
The ASIC 112 is an integrated circuit that amplifies and processes the electric signal output from
the MEMS chip 111.
[0010]
03-05-2019
3
The bottom case 101 has a recess 1011 in which the microphone substrate 102 and the top case
103 are accommodated as shown in FIG. In a bottom wall 1011 a of the recess 1011 of the
bottom case 101, a groove 1012 formed in a substantially rectangular shape in a plan view is
formed. A plurality of electrode terminals 1013 electrically connected to electrode terminals (not
shown) provided on the bottom surface 101 a of the bottom case 101 are provided on the
bottom wall 1011 a of the recess 1011 of the bottom case 101.
[0011]
A plurality of electrode terminals 1013 includes an electrode terminal for power supply for
supplying power to the microphone unit 100, an electrode terminal for output for outputting an
electric signal generated by the microphone unit 100 to the outside, and a ground connection.
Electrode terminals are included. The electrode terminal formed on the bottom case 101 is
integrally formed with the bottom case 101, for example, by insert molding.
[0012]
The microphone substrate 102 is formed with a first through hole 1021 and a second through
hole 1022. These are provided to form a sound path for guiding an external sound wave to the
diaphragm 113 of the MEMS chip 111. Further, in order to electrically connect, for example, the
MEMS chip 111 and the ASIC 112 to the microphone substrate 102, and to ensure the electrical
connection with the electrode terminal 1013 formed on the bottom case 101, Wiring patterns
1023 (details not shown but including internal wirings formed in the substrate) are formed.
[0013]
The MEMS chip 111 and the ASIC 112 mounted on the microphone substrate 102 are flip-chip
mounted or wire-bonded mounted, for example.
[0014]
In the top plate portion 103 a of the top case 103, two openings 1031 and 1032 having a
substantially elliptical shape in plan view are formed.
03-05-2019
4
In the top case 103, a first space portion 1033 in communication with the first opening 1031,
and a second space portion 1034 separated from the first space portion 1033 and in
communication with the second opening are provided. It is formed.
[0015]
For example, the microphone unit 100 of the prior development is formed by fitting the
microphone substrate 102 having the MEMS chip 111 and the ASIC 112 mounted on the bottom
case 101 and then fitting the top case 103 onto the bottom case 101 so as to cover the
microphone substrate 102. can get.
[0016]
The electrode terminal 1013 provided on the recess bottom wall 1011 a of the bottom case 101
is electrically joined to the electrode terminal provided on the microphone substrate 102 using,
for example, solder or conductive paste.
Also, the microphone substrate 102 and the top case 103 are bonded using an adhesive.
Furthermore, in order to prevent sound leakage in the microphone unit 100, after the top case
103 is fitted into the bottom case 101, a sealing resin (for example, epoxy resin) is used to cover
the gap between the bottom case 101 and the top case 103. Resin) is adhered.
[0017]
As shown in FIG. 20, in the microphone unit 100, the second space portion 1034 is inserted
through the second through hole 1022 so that the MEMS chip 111 and the ASIC 112 are
accommodated in the first space portion 1033. The top case 103 is placed on the microphone
substrate 102 so as to communicate with the groove 1012.
[0018]
As a result, the sound generated outside the microphone unit 100 passes through the first
opening 1031 and the first space portion 1033 and reaches the upper surface 113 a of the
diaphragm 113 of the MEMS chip 111.
03-05-2019
5
The sound generated outside the microphone unit 100 passes through the second opening 1032,
the second space 1034, the second through hole 1022, the groove 1012, and the first through
hole 1021 in this order, and the MEMS chip 111 The lower surface 113 b of the diaphragm 113
is reached.
[0019]
When applied to a close talk type voice input device (for example, a cellular phone), the
microphone unit 100 of the prior development thus configured converts only the target voice
from which noise is removed into an electrical signal and outputs it. Function as a highperformance microphone unit. This is due to the following reasons.
[0020]
The sound pressure of a sound wave (amplitude of the sound wave) is inversely proportional to
the distance from the sound source. Then, the sound pressure attenuates sharply at a position
close to the sound source, and gently attenuates as it gets away from the sound source.
Therefore, the user's voice generated near the microphone unit 100 and incident on the
diaphragm 113 through the sound hole (the first opening 1031 or the second opening 1032) is
the upper surface 113a and the lower surface 113b of the diaphragm 113. Causes a large sound
pressure difference to vibrate the diaphragm 113. On the other hand, noises incident on the both
surfaces 113a and 113b of the diaphragm 113 from a distance reach almost the same sound
pressure when reaching the diaphragm 13, cancel each other, and hardly vibrate the diaphragm
113.
[0021]
Therefore, the sound pressure for vibrating the diaphragm 113 can be regarded as the sound
pressure indicative of the user's voice, and the electrical signal acquired based on the vibration of
the diaphragm 113 has the user's voice from which the noise has been removed. It can be
regarded as an electrical signal to be shown.
[0022]
03-05-2019
6
In addition, the microphone unit 100 of the prior development has a diaphragm case by
preparing the bottom case 101 in which the groove portion 1012 is formed and housing and
holding the microphone substrate 102 and the top case 103 in the bottom case 101 as an
unconventional configuration. Two sound introduction spaces for guiding the sound waves to
both surfaces 113a and 113b of 113 are obtained.
In this configuration, the positional relationship between the respective members can be made to
be a desired positional relationship only by fitting the microphone substrate 102 and the top
case 103 into the bottom case 101. For this reason, according to the microphone unit 100 of the
prior development, it is possible to efficiently assemble the differential type microphone unit with
a small number of parts.
[0023]
By the way, in the case of the microphone unit 100 of the prior development, it is not preferable
to make the distance between two sound holes (corresponding to the first opening 1031 and the
second opening 1032) shorter than a predetermined distance. It has been considered difficult to
miniaturize in the direction parallel to the direction of contraction (direction of arrow D in FIG.
20).
[0024]
The reason why it is not preferable to make the distance between the two sound holes shorter
than a predetermined distance is as follows.
That is, when the distance between the two sound holes is shorter than a predetermined distance
(for example, about 5 mm), the difference in sound pressure applied to the upper surface 113a
and the lower surface 113b of the diaphragm 113 becomes smaller. As a result, the amplitude of
the diaphragm 113 accompanying the input to the sound wave becomes small, and the SNR
(Signal to Noise Ratio) of the electric signal output from the microphone unit 100 becomes
worse.
[0025]
In view of the above, it is an object of the present invention to provide a differential microphone
unit that can be efficiently assembled and can be easily miniaturized.
03-05-2019
7
[0026]
In order to achieve the above object, in the microphone unit of the present invention, there is an
electro-acoustic conversion unit having a diaphragm displaced by sound pressure to convert a
sound signal into an electric signal, and a storage space for storing the electro-acoustic
conversion unit. A microphone unit comprising: a housing to be formed; and a mounting member
for mounting the housing in a first recess, wherein the housing space of the housing includes a
first wall portion and the first wall. It is formed by the 2nd wall opposite to a wall, and the 3rd
wall which connects the 1st wall and the 2nd wall, and the above-mentioned case is the 1st wall
Portion is disposed opposite to the bottom wall of the first recess, and at least a part of the third
wall is mounted on the mounting member such that it is disposed opposite to the side wall of the
first recess; When the first wall side is the lower side and the second wall side is the upper side,
The portion is disposed on the upper surface of the first wall portion so as to cover at least a part
of the opening formed on the upper surface of the first wall portion and to close the opening, and
the electro-acoustic transducer A lower space communicating with the opening is formed on the
lower side of the portion, and a first space for guiding an external sound from the upper side to
the lower space and a second space for guiding an external sound to the accommodation space
are formed. At least one of the first space and the second space is characterized by using a space
formed between a wall portion of the housing and a side wall of the first recess.
[0027]
According to this configuration, an external sound can be guided to one of the diaphragms
through the first space, the lower space, and the opening (provided on the first wall), and the
second space and the housing space can be used. Thus, the external sound can be guided to the
other side of the diaphragm.
Then, external sound can be conducted to the diaphragm from the same side (upper side) of the
first space and the second space.
For this reason, according to this configuration, it is possible to obtain a differential type
microphone unit capable of guiding external sound to both surfaces of the diaphragm from the
same surface side of the microphone unit.
[0028]
03-05-2019
8
Further, in the present configuration, at least one of the first space and the second space is
configured using a space formed between the wall portion of the housing and the side wall of the
first recess. Into the two sound holes to introduce the external sound (the entrance part to
introduce the external sound. Hereinafter, without shortening the spacing between the two sound
holes, it is possible to miniaturize in the direction parallel to the direction in which the spacing
between the two sound holes is shortened. Further, according to this configuration, by mounting
the housing in the concave portion (first concave portion) of the mounting member, two sound
paths can be obtained which guide the sound waves to both surfaces of the diaphragm, and
alignment between the respective members is easy. Thus, the microphone unit can be assembled
efficiently.
[0029]
In the microphone unit of the above configuration, the lower space may be formed by using a
second recess formed in a bottom wall of the first recess. According to this configuration, the
lower space can be easily obtained by mounting the housing in the concave portion (first concave
portion) of the mounting member. The configuration for obtaining the lower space is not limited
to this configuration. For example, the first recess bottom wall of the mounting member is not
provided with a recess (second recess), and is cut on the lower surface side of the first wall You
may obtain as a structure etc. which provide a notch part, or provide a hollow part in a 1st wall
part.
[0030]
In the microphone unit configured as described above, a first groove may be formed on the side
wall of the first recess to form the first space together with the outer wall of the third wall.
According to this configuration, it is not necessary to provide two spaces isolated in the housing,
and parallel to the direction of shortening the distance between the two sound holes without
shortening the distance between the two sound holes for introducing the external sound. Can be
miniaturized. In the present configuration, for example, a through hole may be formed in the
second wall portion to obtain the second space.
[0031]
03-05-2019
9
In the microphone unit configured as described above, a second groove that forms the second
space together with the side wall of the first recess may be formed on the side surface of the
second wall. According to this configuration, the opening surface can be provided on the side
surface of the housing, and the space between the two sound holes for introducing the external
sound is shortened by the thickness of the side wall. It is possible to miniaturize the direction
parallel to the direction of shortening the distance. In this configuration, for example, the first
space may be formed by the through holes penetrating the second wall, the third wall, and the
first wall from the upper side to the lower side. Alternatively, the first space may be formed using
the above-described first groove portion.
[0032]
In the microphone unit configured as described above, all of the three wall portions may be
disposed to be opposed to the side wall of the first recess. According to this configuration, it is
convenient because the microphone unit in a state in which the respective members can be
aligned can be obtained by a simple operation of fitting the housing into the first recess of the
mounting member.
[0033]
In the microphone unit configured as described above, a part of the side surface of the first
recess is an opening surface, and a part of the third wall is not disposed to face the side wall of
the first recess. It is also good. In the case of this configuration, when the housing is mounted in
the first recess, the microphone unit can be obtained by sliding and mounting the housing in a
predetermined direction, and the alignment between the respective members can be performed.
Therefore, even in this configuration, it is possible to assemble the microphone unit efficiently.
Further, in the present configuration, since a part of the side surface of the first recess is the
opening surface, the mounting member can be miniaturized, and the microphone unit can be
further miniaturized.
[0034]
As a more specific configuration of the microphone unit having the above configuration, the
housing and the first recess have a substantially rectangular parallelepiped shape, and the first
space and the second space are arranged in parallel in the longitudinal direction. It is also good.
03-05-2019
10
According to this configuration, it is possible to obtain a differential microphone unit that can be
efficiently assembled and that can be easily miniaturized in the longitudinal direction of the
microphone unit.
[0035]
In the microphone unit configured as described above, the first surface for introducing the
external sound of the first space and the second surface for introducing the external sound of the
second space may be substantially on the same plane. Such a configuration is convenient because
the configuration when attaching the microphone unit to the voice input device is not
complicated.
[0036]
In the microphone unit of the above configuration, the housing preferably includes a microphone
substrate on which the electroacoustic transducer is mounted, and a lid which is placed on the
microphone substrate. As a result, the microphone unit can be configured with a small number of
parts, and it is easy to miniaturize the differential microphone unit and to improve the efficiency
of the assembly operation.
[0037]
According to the present invention, it is possible to provide a differential type microphone unit
which can be efficiently assembled and which can be easily miniaturized.
[0038]
1 is a schematic perspective view showing the external configuration of the microphone unit
according to the first embodiment an exploded perspective view showing the configuration of the
microphone unit according to the first embodiment a schematic sectional view taken along the
line A-A of FIG. Schematic plan view when the case is viewed from the top Schematic sectional
view showing the configuration of the MEMS chip provided in the microphone unit of the first
embodiment Schematic sectional view for explaining the effect of the microphone unit of the first
embodiment Second embodiment FIG. 8 is a schematic perspective view showing the external
configuration of the microphone unit of the present invention. FIG. 7 is a schematic sectional
view taken along the line B-B in FIG. 7 schematically showing the bottom case of the microphone
unit of the second embodiment. The schematic perspective view which shows The structure of
03-05-2019
11
the bottom case with which the microphone unit of 3rd Embodiment is provided is shown.
Schematic plan view Schematic perspective view showing the configuration of the lid provided in
the microphone unit of the third embodiment The schematic sectional view at position C-C in FIG.
10 A schematic sectional view for explaining the effect of the microphone unit of the third
embodiment A schematic sectional view showing a modification of the microphone unit of the
third embodiment. A schematic perspective view showing an appearance configuration of the
microphone unit of the fourth embodiment. A schematic sectional view at a position D-D of FIG.
16 shows a modification of the microphone unit of the embodiment. Schematic cross-sectional
view An exploded perspective view showing the configuration of the microphone unit previously
developed by the present applicants A schematic cross-sectional view showing the configuration
of the microphone unit previously developed by the present applicants
[0039]
Hereinafter, embodiments of a microphone unit to which the present invention is applied will be
described in detail with reference to the drawings.
[0040]
First Embodiment First, the configuration of the microphone unit of the first embodiment will be
described with reference to FIGS. 1 to 5.
[0041]
In addition, FIG. 1 is a schematic perspective view which shows the external appearance
structure of the microphone unit of 1st Embodiment.
FIG. 2 is an exploded perspective view showing the configuration of the microphone unit of the
first embodiment.
FIG. 3 is a schematic cross-sectional view at a position A-A in FIG.
FIG. 4 is a schematic plan view of the bottom case provided in the microphone unit of the first
embodiment as viewed from above.
03-05-2019
12
FIG. 5 is a schematic cross-sectional view showing the configuration of the MEMS chip provided
in the microphone unit of the first embodiment.
[0042]
The microphone unit 1 according to the first embodiment includes a bottom case 10, a
microphone substrate 20 on which the MEMS chip 40 and the ASIC 50 are mounted, and a lid 30
disposed to cover the microphone substrate 20. First, the configuration of these units included in
the microphone unit 1 will be described.
[0043]
The bottom case 10 has a substantially rectangular parallelepiped outer shape, and has a first
recess 11 in which the microphone substrate 20 and the lid 30 are accommodated. The first
recess 11 of the bottom case 10 includes four side walls 11a to 11d and a bottom wall 11e, and
the first recess 11 has a substantially rectangular parallelepiped shape. The bottom case 10 is an
embodiment of the mounting member of the present invention.
[0044]
Of the four side walls 11a to 11d of the first recess 11, one side wall 11a is formed with a first
groove 12 having a substantially rectangular shape in plan view extending from the upper
surface 11f of the first recess 11 to the bottom wall 11e. It is done. In the bottom wall 11 e of the
first recess 11, a second recess 13 having a substantially rectangular shape in plan view is
formed. The first groove 12 and the second recess 13 are connected, and when the bottom case
11 is viewed from above, the first groove 12 and the second recess 13 have a substantially
rectangular shape as shown in FIG. It looks like
[0045]
The bottom case 10 is formed of, for example, a resin. When the microphone unit 1 is reflowmounted on a mounting substrate (not shown) of a voice input device (for example, a mobile
phone or the like), the bottom case 10 is preferably made of heat-resistant resin. In consideration
03-05-2019
13
of such a point etc., the bottom case 10 is preferably formed using a resin such as LCP (Liquid
Crystal Polymer) or PPS (polyphenylene sulfide).
[0046]
Although not shown, a plurality of electrode terminals are formed on the bottom wall 11 e of the
first recess 11 of the bottom case 10 and the bottom surface 10 a of the bottom case 10 using,
for example, insert molding. This is the same as the microphone unit 100 of the prior
development shown in FIGS. 19 and 20, and a plurality of electrode terminals include an
electrode terminal for power supply for supplying power to the microphone unit 1 and electricity
generated by the microphone unit 1 It includes an electrode terminal for output that outputs a
signal to the outside, and an electrode terminal for ground connection.
[0047]
The microphone substrate 20 is formed in a substantially rectangular shape in a plan view, and
the size thereof is formed to be substantially equal to (slightly smaller than) the width X and the
depth Y (see FIG. 4) of the first recess 11 of the bottom case 10 There is. The microphone
substrate 20 is formed with a first through hole 21 (an embodiment of the opening of the
present invention) having a substantially rectangular shape in plan view. The MEMS chip 40 is
disposed on the microphone substrate 20 so as to close the first through hole 21. The MEMS
chip 40 is an embodiment of the electroacoustic transducer of the present invention.
[0048]
The MEMS chip 40 is made of a silicon chip, and as shown in FIG. 5, has an insulating base
substrate 41, a diaphragm 42, an insulating layer 43, and a fixed electrode 44, and constitutes a
capacitor type microphone. ing. The base substrate 41 is formed with an opening 41 a having a
substantially circular shape in plan view. The diaphragm 42 provided on the base substrate 41 is
a thin film that vibrates (vibrates in the vertical direction) by receiving a sound pressure, has
conductivity, and forms one end of the electrode. The fixed electrode 44 is disposed to face the
diaphragm 42 with the insulating layer 43 interposed therebetween. Thereby, a capacitance is
formed between the diaphragm 42 and the fixed electrode 44. In the fixed electrode 44, a
plurality of through holes 44a are formed to allow sound waves to pass therethrough.
03-05-2019
14
[0049]
The diaphragm 42 of the MEMS chip 40 vibrates according to the difference between the sound
pressure pf applied from the upper surface 42 a and the sound pressure pb applied from the
lower surface 42 b. When the diaphragm 42 vibrates, the distance Gp between the diaphragm 42
and the fixed electrode 44 changes, and the capacitance between the diaphragm 42 and the fixed
electrode 44 changes. As a result, the sound wave (sound signal) incident on the MEMS chip 40
can be extracted as an electric signal.
[0050]
The ASIC 50 is an integrated circuit that amplifies an electrical signal extracted based on a
change in capacitance of the MEMS chip 40. The ASIC 50 functioning as the signal processing
unit may include a charge pump circuit for applying a bias voltage to the MEMS chip 50 and an
amplifier circuit for detecting a capacitance change in the MEMS chip 50.
[0051]
In the microphone unit 1, the MEMS chip 40 is mounted on the microphone substrate 20 so that
the diaphragm 42 is substantially parallel to the microphone substrate 20 and at least a part of
the diaphragm 42 covers the first through hole 21. ing. Further, on the microphone substrate 20,
an ASIC 50 is disposed adjacent to the MEMS chip 40. The MEMS chip 40 and the ASIC 50 are
mounted on the microphone substrate 20 by flip chip mounting or wire bonding, for example.
[0052]
On the microphone substrate 20, a wiring pattern (including internal wiring) not shown is
formed. Thus, the electric signal extracted from the MEMS chip 40 and amplified by the ASIC 50
can be output to the outside of the microphone unit 1 through the electrode terminal formed on
the bottom case 10. Further, power supply power can be supplied from the outside via an
electrode terminal formed on the bottom case 10. Besides, in the microphone substrate 20, a
wire for ground connection is also formed.
03-05-2019
15
[0053]
The lower surface (the lower surface of the MEMS chip 40) of the MEMS chip 40 is bonded to a
frame-shaped connection pad (not shown) formed so as to surround the first through hole 21 by,
for example, solder or the like. As a result, the sound does not leak from the gap formed between
the upper surface of the microphone substrate 20 and the lower surface of the MEMS chip 40.
[0054]
When the MEMS chip 40 is mounted on the microphone substrate 20, the following bonding
method (an example of wire bonding mounting) may be employed as a bonding method other
than the bonding (an example of flip chip mounting) by the above-described solder. Absent. That
is, a die attach (die bonding adhesive) is applied to a portion where the MEMS chip 40 is
mounted on the microphone substrate 20, and the MEMS chip 40 is bonded by die bonding.
Then, the MEMS chip 40 and the ASIC 50 and the ASIC 50 and an electrode formed on the
microphone substrate 20 are electrically bonded by wire bonding. Here, the upper surface of the
microphone substrate 20 and the lower surface of the MEMS chip 40 need to be completely diebonded without any gap, so that sound does not leak from the gap.
[0055]
Moreover, the material of the board ¦ substrate which comprises the microphone board ¦
substrate 20 is not specifically limited, For example, a glass epoxy board ¦ substrate, a polyimide
substrate, a silicon substrate, a glass substrate etc. are used. However, in order to reduce the
stress on the MEMS chip 40 due to heating and cooling at the time of reflow, it is preferable to
select the material of the substrate so that the linear expansion coefficient of the microphone
substrate 20 becomes close to the linear expansion coefficient of the MEMS chip 40 .
[0056]
The lid 30 is composed of a top plate portion 30a in which a second through hole 31 having a
substantially rectangular shape in plan view is formed, and a side wall portion 30b having four
surfaces. The outer shape of the lid 30 has a substantially rectangular parallelepiped shape, and
03-05-2019
16
the lid 30 has a substantially rectangular parallelepiped recess. The width and depth of the lid 30
are substantially the same as the size of the microphone substrate 20. For this reason, in a state
in which the lid 30 is covered on the microphone substrate 20, the outer shape thereof (the outer
shape of the casing composed of the lid 20 and the microphone substrate 20) is substantially
rectangular parallelepiped.
[0057]
The lid 30 is formed of, for example, a resin. When the microphone unit 1 is reflow-mounted on a
mounting substrate (not shown) of a voice input device (for example, a mobile phone or the like),
the lid 30 is preferably made of a heat-resistant resin. In consideration of such points etc., it is
preferable to form the lid 30 using a resin such as LCP (Liquid Crystal Polymer; liquid crystal
polymer) or PPS (polyphenylene sulfide).
[0058]
Next, the configuration of the microphone unit 1 in which the microphone substrate 20 on which
the MEMS chip 40 and the ASIC 50 are mounted and the lid 30 are fitted in the bottom case 30
will be described.
[0059]
Here, when the microphone substrate 20 and the lid 30 are fitted into the bottom case 10, the
microphone substrate 20 and the lid 30 may be fitted in this order.
As another method, the lid 30 is put on the microphone substrate 20, and the case 60 having the
internal space 62 (the embodiment of the accommodation space of the present invention) in
which the MEMS chip 40 and the ASIC 50 are accommodated is configured first. The housing 60
may be fitted into the bottom case 10.
[0060]
The microphone substrate 20 and the lid 30 are bonded, for example, by an adhesive. The
bottom case 10 and the microphone substrate 20 are bonded using solder, conductive paste, or
03-05-2019
17
the like so that the connection terminals are electrically connected to each other. In addition, in
order to prevent sound leakage in the microhonin unit 1, an epoxy resin or the like is used to
cover a gap between the housing 60 and the bottom case 10 (refers to a gap that is temporarily
cut but not used as a sound path). It is preferable to bond the sealing resin of
[0061]
The microphone unit 1 can also be said to be a configuration in which a housing 60 composed of
the microphone substrate 20 and the lid 30 is fitted in the first recess 11 of the bottom case 10
(see FIG. 3). When viewed in this manner, in the case 60, the microphone substrate 20
constituting the case 60 is disposed to face the bottom wall 11e of the first recess 11 of the
bottom case 10, and the lid constituting the case 60 The bottom case 10 is mounted such that
the side wall portions 30 b of 30 are disposed to face the side walls 11 a to 11 d of the first
recess 11 of the bottom case 10.
[0062]
Although temporarily suspended, in the microphone unit 1, all of the side wall portions 30 b
constituting the housing 60 (all four surfaces) are arranged to be opposed to the side walls of the
recess 11. Further, the upper surface of the case 60 (specifically, the upper surface of the top
plate portion 30a of the lid 30 corresponds) and the upper end of the bottom case 10 (the same
as the upper surface 11f of the first recess 11) are in the same plane. The upper part of the unit
1 is flat.
[0063]
The microphone substrate 20 is an embodiment of the first wall portion of the present invention.
Further, the top plate portion 30a of the lid 30 is an embodiment of the second wall portion
facing the first wall portion of the present invention, and the side wall portion 30b of the lid 30 is
the first wall portion of the present invention Fig. 7 is an embodiment of a third wall connecting
the second walls;
[0064]
In the microphone unit 1, since the housing 60 has substantially the same size as the width X
03-05-2019
18
and the depth Y of the first recess 11 (X and Y refer to FIG. 4), the first recess 11 of the bottom
case 10 is By fitting the housing 60, the first recess 11 is occupied by the housing 60.
[0065]
On the other hand, the first side 11a formed in the side wall 11a of the first recess 11 (of the two
side walls 11a and 11c opposed to each other in the longitudinal direction of the first recess 11
with a greater distance from the second through hole 31) The space of the groove 12 and the
second recess 13 formed in the bottom wall 11 e of the first recess 11 is not occupied by the
housing 60.
For this reason, the first space formed by the first groove 12 and the outer surface of the housing
60 (the outer wall surface of the side wall 30b of the lid 30) by fitting the housing 60 in the first
recess 11 A sound introducing space is formed by the lower space 65 formed by using the
second recess 61 and the outer surface of the housing 60 (the lower surface of the microphone
substrate 20) and connected to the first space 61. The housing 60 is mounted in the first recess
11 so that the first through hole 21 overlaps with a part of the second recess 13.
[0066]
In the above first space 61, the upper end face 12a of the groove 12 (the embodiment of the first
aspect of the present invention) is a sound hole for introducing an external sound, and from this
sound hole 12a the first space 61 The external sound introduced into the lower space 65 and the
first through hole 21 reaches the lower surface 42 b of the diaphragm 42. In the microphone
unit 1, separately from this, from the upper end face 31a (embodiment of the second surface of
the present invention; sound hole) of the second through hole 31 (embodiment of the second
space of the present invention) A sound conducting space is also formed which extends to the
upper surface 42 a of the diaphragm 42 through the internal space 62 formed by covering the
lid 30 on the microphone substrate 20. Therefore, the microphone unit 1 constitutes a
differential microphone unit that vibrates the diaphragm 42 based on the difference in sound
pressure applied to both surfaces of the diaphragm 42.
[0067]
03-05-2019
19
The sound wave travels from the sound hole 12a (upper end face of the groove 12) to the lower
surface 42b of the diaphragm 42, and the sound wave travels from the sound hole 31a (upper
end face of the second through hole 31) to the upper surface 42a of the diaphragm 42. It is
preferable to form the above two sound introducing spaces so as to be approximately equal to
the time to reach them. In this sense, the difference in volume between the two sound
introducing spaces is preferably within ± 30%.
[0068]
Further, in the microphone unit 1, the two sound holes 12a and 31a have a substantially
rectangular shape in plan view, but the shape of the sound holes is not limited to this structure.
That is, as the shape of the sound hole, for example, a substantially semicircular shape in a plan
view or a substantially elliptical shape in a plan view may be adopted. However, like the
microphone unit 1, it is preferable that the long holes of the sound holes 12 a and 31 a be long
holes perpendicular to the direction in which the two sound holes are arranged (longitudinal
direction of the microphone unit 1). As a result, the size of the longitudinal direction of the
microphone unit 1 (corresponding to the left and right direction in FIG. 3) can be easily reduced,
and the acoustic characteristics can be advantageous.
[0069]
In the microphone unit 1, the distance L between the centers of the two sound holes 12a and 31a
is preferably 4 mm or more and 6 mm or less, and more preferably, the distance L between the
centers is about 5 mm. This is because, if the center-to-center distance L between the two sound
holes 12a and 31a is too short, the difference in sound pressure applied to the upper surface 42a
and the lower surface 42b of the diaphragm 42 becomes smaller and the amplitude of the
diaphragm 42 becomes smaller. This is because the SNR of the electrical signal output from V In
addition, if the center-to-center distance L between the two sound holes 12a and 31a is too long,
it is not only disadvantageous for the miniaturization of the microphone unit 1, but also sound
waves emitted from the sound source are transmitted from the two sound holes 12a and 31a.
This is because the difference in time to reach the diaphragm 42, that is, the phase difference
increases, and the noise removal performance is degraded.
[0070]
03-05-2019
20
Next, the operation and effect of the microphone unit 1 configured as described above will be
described. The microphone unit 1 is composed of three members, a bottom case 10, a
microphone substrate 20, and a lid 30, and forms a case having two sound introducing spaces
for guiding sound waves to both surfaces of the diaphragm. Therefore, the differential
microphone unit can be configured with a small number of parts, and miniaturization can be
easily achieved.
[0071]
And, since the microphone unit 1 is a differential type microphone unit, it is applied to a closetalking type voice input device, similarly to the microphone unit 100 of prior development (refer
to FIG. 19 and FIG. 20), It is possible to obtain an electrical signal that shows only the user
speech from which the noise has been removed.
[0072]
Further, since the microphone unit 1 is configured to combine two or more parts to form two
sound introducing spaces, the relative positional relationship between the respective members
becomes important.
In this respect, the microphone unit 1 has a configuration in which the microphone substrate 20
and the lid 30 are fitted in the first recess 11 of the bottom case 10, so that alignment is easy
and workability in assembly is good. .
[0073]
Further, since the microphone unit 1 has a flat top, it is convenient because the sound
introduction space formed in the voice input device is not complicated when applied to the voice
input device. However, the present invention also includes a configuration in which the upper
portion of the microphone unit 1 is not flat (for example, a configuration in which the upper side
of the housing 60 protrudes from the upper surface 11f of the first recess 11 of the bottom case
10) The microphone unit 1 can be said to be a desirable form of the present invention.
[0074]
03-05-2019
21
Furthermore, the microphone unit 1 is advantageous in that the size in the longitudinal direction
(corresponding to the left and right direction in FIG. 3) can be reduced. This will be described
with reference to FIG. FIG. 6 is a schematic cross-sectional view for explaining the effect of the
microphone unit of the first embodiment, the upper part shows the microphone unit 1 of the first
embodiment, and the lower part shows the microphone unit 100 of the prior development.
[0075]
As shown in FIG. 6, the microphone unit 1 makes the distance between the two sound holes 12a
and 31a (center-to-center distance L) the same as the distance between the two sound holes
1031 and 1032 of the microphone unit 100 of the earlier development. The longitudinal size can
be reduced by Δd. This is due to the following reason.
[0076]
The micro-honin unit 1 and the microphone unit 100 of the prior development have the same
sound introducing space for guiding the external sound to the upper surfaces 42 a and 113 a of
the diaphragms 42 and 113. However, the microhonin unit 1 and the microphone unit 100 of the
prior development have different configurations of sound guiding spaces for guiding external
sound to the lower surfaces 42 b and 113 b of the diaphragms 42 and 113.
[0077]
That is, in the microhonin unit 100 of the prior development, a space for housing the MEMS chip
111 and the ASIC 112 in the lid (top case) 103 in order to obtain a sound introducing space for
guiding the external sound to the lower surface 113 b of the diaphragm 113. In addition to
1033, another space 1034 is provided. On the other hand, in the microphone unit 1, the lid 30 is
provided with only one space. Then, in order to obtain a sound introducing space for guiding an
external sound to the lower surface 42 b of the diaphragm 42, the second provided on the
bottom wall 11 e of the first recess 11 on the side wall 11 a of the first recess 11 of the bottom
case 10 The first groove 12 connected to the recess 13 is provided.
[0078]
03-05-2019
22
Thus, in the case where the first groove 12 is provided in the side wall 11a of the first recess 11
of the bottom case 10 to obtain a sound introducing space, two sound holes can be used to
reduce the size of the lid 30 in the longitudinal direction. The longitudinal miniaturization of the
microphone unit 1 is possible while maintaining the distance L.
[0079]
Second Embodiment Next, a microphone unit according to a second embodiment will be
described with reference to FIGS. 7 to 9.
[0080]
FIG. 7 is a schematic perspective view showing the external configuration of the microphone unit
of the second embodiment.
FIG. 8 is a schematic cross-sectional view at a position B-B in FIG.
FIG. 9 is a schematic view showing the configuration of the bottom case provided in the
microphone unit of the second embodiment, and FIG. 9 (a) is a schematic perspective view of the
bottom case viewed obliquely from above, and FIG. 9 (b) is a bottom It is a schematic plan view
when a case is seen from the top.
[0081]
The microphone unit 2 of the second embodiment has the same configuration as the microphone
unit 1 of the first embodiment except that the configuration of the bottom case 10 is slightly
different. For this reason, the same reference numerals are given to the overlapping parts, and
the descriptions thereof will be omitted unless there is a need to particularly describe them.
[0082]
In the bottom case 10 of the microphone unit 2 of the second embodiment, a substantially
rectangular first recess 11 is formed by three side walls 11a to 11c, an opening surface 11g, and
03-05-2019
23
a bottom wall 11e. That is, among the four side surfaces of the first recess 11, one of the side
surfaces is an opening surface, which is different from the configuration of the first embodiment.
As a result, a part (one of the four surfaces) of the side wall portion 30 b of the lid 30 is not
disposed to be opposed to the side wall of the first recess 11. In the microphone unit 1 of the
first embodiment, all the side surfaces of the first recess 11 are walls, and the side wall portions
30 b of the lid 30 are all disposed to face the side walls of the first recess 11.
[0083]
For this reason, the bottom case 10 of the microphone unit 2 is longer in the longitudinal
direction than the bottom case 10 of the microphone unit 1 of the first embodiment by the
thickness of the side wall of the first recess 11 (the horizontal direction in FIG. ) Has become
shorter. For this reason, the microphone unit 2 of the second embodiment can be made smaller
in size in the longitudinal direction as compared with the microphone unit 1 of the first
embodiment.
[0084]
In the microphone unit 2, a part of the side surface of the first concave portion 11 of the bottom
case 10 is the opening surface 11 g. Therefore, when assembling the microphone unit 2, the
microphone substrate is simply attached to the first concave portion 11 of the bottom case 10.
Just fitting the cover 20 and the lid 30 (or the housing 60) from above does not necessarily
complete the alignment between the members. However, since the microphone unit 2 can be
assembled as follows, also in this configuration, the workability at the time of assembly is good.
[0085]
When assembling the microphone unit 2, slide the microphone substrate 20 and the lid 30 (or
the housing 60) toward the side wall 11 a of the first recess 11 from the opening surface 11 g of
the first recess 11 of the bottom case 10. . In this case, the position where the microphone
substrate 20 and the lid 30 hit the side wall 11 a of the first recess 11 can be set as the position
where the alignment between the respective members can be correctly performed. For this
purpose, the microphone unit 2 can be easily assembled while using a jig for pressing the
microphone substrate 20 and the lid 30 against the side wall 11a.
03-05-2019
24
[0086]
Third Embodiment Next, a microphone unit according to a third embodiment will be described
with reference to FIGS. 10 to 14.
[0087]
FIG. 10 is a schematic perspective view showing the external configuration of the microphone
unit of the third embodiment.
FIG. 11 is a schematic plan view showing the configuration of the bottom case provided in the
microphone unit of the third embodiment. FIG. 12 is a schematic perspective view showing the
configuration of a lid provided in the microphone unit of the third embodiment. FIG. 13 is a
schematic cross-sectional view at a position C-C in FIG. FIG. 14 is a schematic cross-sectional
view for explaining the effect of the microphone unit of the third embodiment. In addition, in FIG.
14, the upper stage shows the microphone unit 3 of 3rd Embodiment, and the lower stage shows
the microphone unit 100 of a prior development.
[0088]
In the microphone unit 1 of the first embodiment, a sound introducing space for guiding an
external sound to the lower surface 42 b of the diaphragm 42 in order to miniaturize the length
in the longitudinal direction of the microphone unit 1 without shortening the distance between
the sound holes. The present invention has been devised (the first space 61 is configured using a
space formed between the wall portion of the housing 60 and the side wall of the first recess 11).
In the microphone unit 3 of the third embodiment, a sound introducing space for guiding an
external sound to the upper surface 42 b of the diaphragm 42 in order to reduce the length in
the longitudinal direction of the microphone unit 1 without shortening the distance between the
sound holes. We are devising devices for That is, the second space is configured using a space
formed between the wall portion of the housing 60 and the side wall of the first recess 11.
[0089]
Hereinafter, although the microphone unit 3 of the third embodiment will be described, the parts
overlapping with the configuration of the first embodiment will be assigned the same reference
numerals, and the description will be omitted for the cases where there is no need to particularly
03-05-2019
25
describe.
[0090]
As shown in FIG. 11, in the bottom case 10 provided in the microphone unit 3, as in the case of
the first embodiment, the first recess 11 has four side walls 11 a to 11 d, and the bottom of the
first recess 11. The second recess 13 is formed in the wall 11 e.
However, it differs from the configuration of the first embodiment in that no groove is provided
in any of the side walls 11 a to 11 d of the first recess 11.
[0091]
As shown in FIG. 12, the lid 30 provided in the microphone unit 3 includes a top plate 30a
(embodiment of the second wall) and a side wall 30b (embodiment of the third wall). . Since one
of the four side surfaces of the lid 30 is an opening surface 30c, the side wall 30b has three wall
surfaces. The lid 30 is formed with a through hole 32 which penetrates the top plate portion 30a
and one of three walls constituting the side wall portion 30b from the upper side to the lower
side (see FIG. 13). The through hole 32 is connected to the through hole 22 (see FIG. 13) formed
in the microphone substrate 10 (the embodiment of the first wall portion) which is joined to the
lid 30 to constitute the housing 60. The two through holes 22 and 32 form a third through hole
63 (an embodiment of the first space of the present invention).
[0092]
The third through hole 63 is connected to the second recess 13 of the bottom case 10 when the
housing 60 is mounted on the bottom case 10. Thus, the external sound introduced from the
upper end face 63a of the third through hole 63 (the embodiment of the first aspect of the
present invention; the sound hole 63a) is the third through hole 63, the second recess 13, and
the like. The lower space 65 formed using the outer surface of the housing 60 (the lower surface
of the microphone substrate 20) and the lower surface 42b of the diaphragm 42 through the
first through hole 21 are formed.
03-05-2019
26
[0093]
Further, as shown in FIG. 12, on the side surface on the side of the opening surface 30b of the
top plate portion 30a, a second groove portion 33 which looks substantially rectangular when
viewed from the upper side is formed. The second groove portion 33 extends from the upper
surface to the lower surface of the top plate portion 30a. The second groove 33 communicates
with the housing space 62 of the housing 60 with the side wall 11 c of the first recess 11 of the
bottom case 10 when the housing 60 is mounted on the bottom case 10. A space 64 is formed
(see FIG. 13). Thereby, the external sound introduced from the upper end face 33a of the second
groove 33 (the embodiment of the second aspect of the present invention; the sound hole 33a) is
the diaphragm 42 through the second space 64 and the housing space 62. To the top surface
42a of the
[0094]
As described above, the microphone unit 3 constitutes a differential microphone unit that
vibrates the diaphragm 42 based on the difference in sound pressure applied to both surfaces of
the diaphragm 42. In the microphone unit 3 as well as the first embodiment, the length, depth,
and height of the housing 60 including the microphone substrate 10 and the lid 30 are equal to
the length X of the first recess 11, and It is almost the same as the depth Y (see FIG. 11) and the
height (the depth of the recess).
[0095]
The microphone unit 3 configured in this way is a case having two sound introducing spaces that
guide sound waves to both surfaces of the diaphragm 42 by the three members of the bottom
case 10, the microphone substrate 20, and the lid 30. There is. Therefore, the differential
microphone unit can be configured with a small number of parts, and miniaturization can be
easily achieved. Further, since the microphone unit 3 has a configuration in which the
microphone substrate 20 and the lid 30 are fitted in the first concave portion 11 of the bottom
case 10, alignment is easy and workability at the time of assembly is good.
[0096]
03-05-2019
27
Further, as shown in FIG. 14, the microphone unit 3 can remove one of the walls constituting the
side surface of the lid 103 in the microphone unit 100 of the prior development. For this
purpose, the size in the longitudinal direction is reduced by Δd while keeping the distance
between the two sound holes 63a and 33a (center distance L) the same as the distance between
the two sound holes 1031 and 1032 of the microphone unit 100 of the prior development. be
able to.
[0097]
In the bottom case 10 of the third embodiment, the side wall 11a of the first recess 11 is
removed as in the second embodiment (in the second embodiment, the side wall 11c of the first
recess 11 is removed). ) May be used as a microphone unit as shown in FIG. 15 (the broken line
portion in FIG. 15 is a portion removed). By this configuration, the length in the longitudinal
direction (corresponding to the left and right direction in FIG. 15) is shortened by the thickness
of the side wall 11 a of the first recess 11. For this reason, the size in the longitudinal direction of
the microphone unit 3 can be further reduced.
[0098]
Fourth Embodiment Next, a microphone unit of a fourth embodiment will be described with
reference to FIG. 16 and FIG. FIG. 16 is a schematic perspective view showing the external
configuration of the microphone unit of the fourth embodiment. FIG. 17 is a schematic crosssectional view at the D-D position of FIG. In the description, the same parts as those in the first
embodiment and the third embodiment are denoted by the same reference numerals, and the
description thereof will be omitted unless it is particularly necessary.
[0099]
The microphone unit 4 of the fourth embodiment has a configuration in which the characterizing
portion of the microphone unit 1 of the first embodiment and the characterizing portion of the
microphone unit 3 of the third embodiment are combined. That is, the first groove 12 is formed
in the side wall 11 a of the first recess 11 of the bottom case 10. Then, a first space 61 formed
by the first groove 12 and the outer wall of the housing 60, a lower space 65 (a space formed by
using the second recess 13), and the first through hole 21 are provided. Through the lower
surface 42 b of the diaphragm 42. The upper end surface 12a of the first groove 12 is an
03-05-2019
28
embodiment of the first surface of the present invention, and constitutes a sound hole.
[0100]
Further, on the side surface of the top plate portion 30a constituting the housing 60, the upper
surface 33a is provided in parallel with the upper end surface 12a of the first groove portion 12
in the longitudinal direction, and from the upper surface to the lower surface of the top plate
portion 30a. An extending second groove 33 is formed. Then, the external sound reaches the
upper surface 42 a of the diaphragm 42 through the second space 64 formed by the second
groove 33 and the side wall 11 c of the first recess 11 of the bottom case 10 and the
accommodation space 62. It is a structure. The upper end surface 33a of the second groove
portion 33 is an embodiment of the second surface of the present invention, and constitutes a
sound hole.
[0101]
The microphone unit 4 configured in this way is a case having two sound introducing spaces that
guide sound waves to both surfaces of the diaphragm 42 by the three members of the bottom
case 10, the microphone substrate 20, and the lid 30. There is. Therefore, the differential
microphone unit can be configured with a small number of parts, and miniaturization can be
easily achieved. Further, since the microphone unit 4 has a configuration in which the
microphone substrate 20 and the lid 30 are fitted in the first recess 11 of the bottom case 10,
alignment is easy and workability at the time of assembly is good. Furthermore, the size in the
longitudinal direction can be reduced while making the distance between the two sound holes
12a and 33a (center-to-center distance L) the same as the distance of the microphone unit 100 of
the first development.
[0102]
(Others) The microphone units 1 to 4 described above are exemplifications of the present
invention, and the scope of application of the present invention is not limited to the configuration
of the embodiment shown above. That is, various changes may be made to the embodiment
described above without departing from the object of the present invention.
03-05-2019
29
[0103]
For example, in the embodiment described above, the lower space 65 provided below the MEMS
chip 40 is configured using the second recess 13 provided in the bottom case 10. However, the
scope of application of the present invention is not intended to be limited to this configuration.
That is, as shown in FIG. 18, for example, the bottom wall of the bottom case 10 is flat and the
groove 14 is provided on the lower surface of the microphone substrate 20, and the space
formed between the bottom case 10 and the wall of the housing 60 The lower space may be
obtained using In this case, the groove portion 14 may be obtained, for example, by cutting a
thick substrate, or may be obtained by bonding a not-cut substrate and a not-cut substrate. In
addition, the lower space may be a hollow portion formed in the microphone substrate 20.
[0104]
In the first, second, and fourth embodiments described above, the first space 61 is formed by the
first groove 12 formed in the side wall 11 a of the first recess 11 of the bottom case 10, and the
housing An outer wall of the body 60 is formed. However, the present invention is not limited to
this. For example, the first space may be formed by the side wall of the first recess 11 of the
bottom case 10 and the groove provided in the outer wall of the housing 60. The first space may
be formed by the groove portion provided on the side wall of the concave portion 11 and the
groove portion provided on the outer wall of the housing 60. In the third and fourth
embodiments described above, the second space 64 is formed by the second groove 33 formed
in the top plate portion 30a of the lid 30 (the housing 60), and the second case 64 of the bottom
case 10. It is set as the structure formed with the side wall 11c of the recessed part 11 of 1. FIG.
However, the present invention is not limited to this, and for example, the second space may be
formed by the side surface portion of the top plate portion 30a of the lid 30 and the groove
portion formed in the side wall 11c of the first recess 11 of the bottom case 10. The second
space may be formed by the groove formed in the top plate 30a of the lid 30 (the housing 60)
and the groove formed in the side wall of the first recess 11 of the bottom case 10. I don't care.
Further, for example, in order to obtain the second space, instead of providing the groove in the
top plate portion 30a, the length of the top plate portion 30a is the same as the case where the
second groove portion 33 is provided and the side wall portion 30b has the same length. The lid
30 may be cut out so as to be short. The point is that the space formed between the side wall of
the first recess 11 and the wall of the housing 60 is used to form the first space or the second
space, so that the distance between the sound holes is constant. As long as the longitudinal
direction of the microphone unit can be miniaturized while maintaining the distance, the
configuration other than the configuration shown in the embodiment may be used.
03-05-2019
30
[0105]
Further, in the embodiment described above, the lid 30 is configured to have two side walls
opposed in the lateral direction. However, the present invention is not limited to this, and it may
be configured not to provide both or one of two side walls opposed in the short direction.
[0106]
Moreover, in the embodiment shown above, although the external shape of the housing ¦ casing
60 set it as the rectangular parallelepiped shape, it is not limited to this structure. That is, for
example, the present invention is applicable to a configuration in which the lid 30 is larger in size
than the microphone substrate 20, or in a configuration in which the microphone substrate 20 is
larger than the lid 30.
[0107]
In the embodiment described above, the MEMS chip 40 and the ASIC 50 are formed as separate
chips, but the integrated circuit mounted on the ASIC 50 is monolithically formed on the silicon
substrate forming the MEMS chip 40 I don't care.
[0108]
In the embodiment described above, the electro-acoustic conversion unit for converting the
sound pressure into the electric signal is the MEMS chip 40 formed by using the semiconductor
manufacturing technology, but the present invention is limited to this configuration. It is not the
purpose.
For example, the electroacoustic transducer may be a condenser microphone using an electrec
film or the like.
[0109]
03-05-2019
31
Further, in the above embodiment, a so-called condenser type microphone is adopted as the
configuration of the electroacoustic transducer (corresponding to the MEMS chip 40 of this
embodiment) included in the microphone unit. However, the present invention can also be
applied to a microphone unit adopting a configuration other than a condenser microphone. For
example, the present invention can be applied to a microphone unit in which an electrodynamic
(dynamic), electromagnetic (magnetic), piezoelectric or the like microphone is adopted.
[0110]
Moreover, in the embodiment described above, the configuration in which the size in the
longitudinal direction of the microphone unit can be reduced is shown. However, the present
invention has an advantage that miniaturization in a direction parallel to the direction in which
the distance between the two sound holes is reduced can be reduced without shortening the
distance between the two sound holes included in the microphone unit. Therefore, for example,
the present invention may be applied to reduce the size of the microphone unit in the short
direction.
[0111]
In addition, the shapes of the microphone units 1 to 4 of the embodiment shown above are
examples, and it is needless to say that the scope of application of the present invention is not
limited to the shapes shown in the embodiments. For example, the present invention can be
applied even if the shape of the microphone unit is an elliptic cylinder or the like.
[0112]
The microphone unit of the present invention is, for example, a voice communication device such
as a mobile phone or transceiver, or a voice processing system adopting a technology for
analyzing the input voice (voice recognition system, voice recognition system, command
generation system, electronic dictionary, translation Devices, voice input remote controllers, etc.,
or recording devices, amplifier systems (loudspeakers), microphone systems, etc.
[0113]
1, 2, 3, 4 microphone unit 10 bottom case (mounting member) 11 first recess 11a to 11d side
wall of first recess 11e bottom wall of first recess 11f top surface of first recess 11g first recess
Opening face 12 first groove portion 12a upper end surface (first surface) of first groove portion
03-05-2019
32
13 second concave portion 20 microphone substrate (first wall portion, part of housing) 21 first
through hole (first wall) Opening) 30 lid (part of housing) 30a top plate of lid (second wall) 30b
side wall of lid (third wall) 31 second through hole (second space) 31a upper end surface (second
surface) of second through hole 33 second groove 33a upper end surface (second surface) of
second groove 40 MEMS chip (electro-acoustic transducer) 42 diaphragm 60 housing 61 First
space 62 Internal space (housing space) 63 Third through hole 63a Third penetration The upper
end surface of the (first surface) 64 second space 65 lower space
03-05-2019
33
1/--страниц
Пожаловаться на содержимое документа