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JP2011120097

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This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
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DESCRIPTION JP2011120097
An object of the present invention is to provide a high quality microphone unit which can be
thinned while suppressing deterioration of microphone characteristics. A microphone unit 1
includes an electroacoustic converter 12 having a diaphragm 122 displaced by sound pressure to
convert a sound signal into an electric signal, and a mounting member 11 on which the
electroacoustic converter 12 is mounted. Equipped with A first opening 21 and a second opening
22 are provided in the mounting surface 11 a on which the electroacoustic transducer 12 of the
mounting member 11 is mounted. The electroacoustic transducer 12 is mounted on the
mounting member such that the surfaces 122a and 122b of the diaphragm 122 to which the
sound pressure is applied and the mounting surface 11a are substantially parallel and the first
opening 21 is covered. The mounting member 11 is provided with an internal space 23
communicating the first opening and the 21st second opening 22. The internal space 23 has two
opposing inner walls 23a and 23b substantially parallel to the mounting surface 11a. A support
14 to be held is provided. [Selected figure] Figure 1
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
system using a technology for analyzing input voice such as a voice authentication system, or a
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recording device. There is.
[0003]
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.
Further, it is preferable to pick up only the target voice (user's voice) at the time of telephone
call, voice recognition and voice recording.
Therefore, as the performance of the microphone unit, it is desirable that the target voice can be
accurately extracted and noise (background noise etc.) other than the target voice can be
removed.
[0004]
With the background as described above, the present applicants are formed so that sound
pressure is applied from both sides of the diaphragm, and are small in size to convert a sound
signal to an electrical signal based on the vibration of the diaphragm based on the sound
pressure difference Development of a microphone unit (hereinafter sometimes referred to as a
differential type microphone unit) is in progress (see, for example, Patent Documents 1 and 2).
[0005]
In the differential microphone unit disclosed in Patent Documents 1 and 2, the user's voice
generated near the microphone unit and incident on both sides of the diaphragm is a loud sound
on one side and the other side of the diaphragm. A pressure difference is generated to vibrate the
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
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signal. That is, according to the differential microphone unit disclosed in Patent Documents 1 and
2, it is possible to convert only the target voice from which noise is removed into an electric
signal and output it.
[0006]
JP 2008-258904 A JP 2009-135777 A
[0007]
By the way, the present applicants have improved the differential type microphone unit as shown
in Patent Documents 1 and 2, and for example, have developed the microphone unit 100 which
can be thinned as shown in FIG.
A microphone unit 100 shown in FIG. 8 includes a microphone substrate 101 and a MEMS
(Micro Electro Mechanical System) chip 102 having a diaphragm 103 displaced by sound
pressure and converting a sound signal into an electric signal.
[0008]
A first opening 104 and a second opening 105 are provided on the top surface 101 a of the
microphone substrate 101. The first opening 104 and the second opening 105 communicate
with each other by a substrate internal space 106 provided inside the microphone substrate 101.
The MEMS chip 102 is disposed to cover the first opening 104.
[0009]
By configuring the microphone unit 100 in this manner, sound pressure is applied to the
diaphragm 103 of the MEMS chip 102 from the upper surface 103 a side and the lower surface
103 b side, and the diaphragm 103 is generated by the difference in sound pressure applied to
both surfaces 103 a and 103 b. Vibrates. Sound pressure is applied to the lower surface 103 a of
the diaphragm 103 by passing through the second opening 105, the substrate internal space
106, and the first opening 104 in this order and reaching the diaphragm 103.
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[0010]
In this newly developed microphone unit 100, the diaphragm 103 and the microphone substrate
101 are disposed so as to be substantially parallel to each other, and the substrate internal space
106 provided in the microphone substrate 10 is used as a sound path. In addition, it is possible
to reduce the thickness of the differential microphone unit. However, it has been found that the
newly developed microphone unit 100 has the following problems.
[0011]
That is, when the microphone substrate 101 is made thin in order to make the microphone unit
100 thinner, the substantial thickness of the portion where the substrate internal space 106 is
provided becomes very thin (for example, about 0.2 mm thick), this portion Is easy to bend. And
this board ¦ substrate interior space 106 might become narrow by this bending. As described
above, the substrate internal space 106 is used as a sound path, and narrowing of the substrate
internal space 106 may lead to an increase in acoustic resistance, resulting in deterioration of the
microphone characteristics.
[0012]
In addition, when the MEMS chip 102 is die-bonded onto the microphone substrate 101, or when
wire bonding is performed to form a wiring, a force is applied to press the MEMS chip 102
toward the microphone substrate 101. When the thin microphone substrate 101 is used, such a
force easily causes a portion where the substrate internal space 106 is provided to be bent,
which may cause die bonding failure or wire connection failure. Further, there is a case in which
the substrate internal space 106 is narrowed due to the distortion generated by performing the
die bonding or the wire bonding, which causes the deterioration of the microphone
characteristics. In addition, when the microhonin unit 100 is mounted on the mounting substrate
of the voice input device, a force is applied to the microphone substrate 101 to narrow the
internal space 106 of the substrate as described above, which may cause deterioration of the
microphone characteristics .
[0013]
In view of the above, it is an object of the present invention to provide a high quality microphone
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unit which can be thinned while suppressing deterioration of the microphone characteristics.
[0014]
In order to achieve the above object, the microphone unit according to the present invention
includes an electro-acoustic conversion unit having a diaphragm displaced by sound pressure to
convert a sound signal into an electric signal, and a mounting member on which the electroacoustic conversion unit is mounted And a first opening and a second opening are provided on
the mounting surface of the mounting member on which the electro-acoustic transducer is
mounted, the electro-acoustic transducer being The surface of the diaphragm to which the sound
pressure is applied and the mounting surface are substantially parallel, and the mounting
member is mounted on the mounting member so as to cover the first opening, and the mounting
member includes the first opening and the first opening. An internal space communicating with
the opening 2 is provided, and the internal space is provided with a support portion held by two
opposing inner walls substantially parallel to the mounting surface.
[0015]
According to this configuration, it is possible to apply sound pressure from both sides of the
diaphragm provided in the electroacoustic transducer, and a differential microphone unit can be
obtained.
The surface of the diaphragm to which the sound pressure is applied and the mounting surface
of the mounting member (the above-described microphone substrate is an example of the
mounting member) on which the electroacoustic transducer is mounted is substantially parallel
to the mounting member. Since the internal space provided is used as a sound path, thinning of
the differential microphone unit can be achieved.
Further, in the internal space formed in the mounting member, a support portion held by two
opposing inner walls substantially parallel to the mounting surface on which the electroacoustic
transducer is mounted is provided, so the thickness of the mounting member Even in the case
where the thickness of the mounting member is made thin, the bending of the mounting member
can be suppressed. That is, according to the present configuration, it is possible to suppress the
narrowing of the internal space due to the bending of the mounting member, and it is possible to
achieve the thinning of the microphone unit while suppressing the deterioration of the
microphone characteristics.
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[0016]
In the microphone unit of the above configuration, it is preferable that the support portion be
provided so as to overlap the electroacoustic transducer portion in plan view in a direction
substantially orthogonal to the mounting surface.
[0017]
According to this configuration, since the support portion is provided in the vicinity of the
portion where the force is easily applied to the mounting member at the time of manufacturing
the microphone unit, etc., narrowing of the internal space due to the bending of the mounting
member at the time of manufacturing is suppressed. It's easy to do.
[0018]
In the microphone unit of the above configuration, the mounting member may be composed of a
plurality of members.
In this way, it is easy to form a mounting member having an internal space.
In this case, for example, the mounting member may be formed of a plurality of types of
members, such as forming the mounting member by combining the substrate and the resin.
[0019]
Further, the mounting member may be formed by bonding a plurality of substrates. In the case of
this configuration, it is preferable that the support portion be integrally formed on one of the
plurality of substrates. When thinning the microphone unit, the internal space formed in the
mounting member is also extremely thin, so it is better to provide the support integrally with the
substrate than to provide the support as a separate member from the substrate. , The
microphone unit can be easily manufactured.
[0020]
The microphone unit further includes a lid provided with a first space and a second space
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separated from the first space, wherein the first space of the lid is the electro-acoustic
transducer. The diaphragm is mounted on the mounting member so as to be separated from the
internal space, and the second space communicates with the internal space through the second
opening, and one surface of the diaphragm is the first space and the lid The diaphragm
communicates with the outside through the first sound hole provided in the body, and the other
surface of the diaphragm is the first opening, the internal space, the second opening, the second
space, and the lid. It may be in communication with the outside through a second sound hole
provided in the body.
[0021]
According to this configuration, it is possible to reduce the thickness of the differential
microphone unit having the lid, while suppressing the deterioration of the microphone
characteristics.
[0022]
According to the present invention, it is possible to provide a high quality microphone unit which
can be thinned while suppressing deterioration of microphone characteristics.
[0023]
Schematic showing the configuration of the microphone unit of the present embodiment
Schematic plan view of two substrates constituting the mounting member of the microphone unit
of the present embodiment viewed from above Configuration of the MEMS chip provided in the
microphone unit of the present embodiment A schematic plan view for explaining another form
of the support portion provided in the internal space, a schematic plan view mounting member
for explaining another form of the support portion provided in the internal space, the substrate
and the resin molding member FIG. 6 is a view showing an example of the configuration of a
resin molded member when configured using the first embodiment of the present invention,
showing the configuration of the microphone unit having a lid; FIG. Schematic cross section
showing the configuration of the developed differential microphone unit
[0024]
Hereinafter, embodiments of a microphone unit to which the present invention is applied will be
described in detail with reference to the drawings.
[0025]
First, the configuration of the microphone unit of the present embodiment will be described.
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[0026]
FIG. 1 is a schematic view showing the configuration of the microphone unit of the present
embodiment, where the upper part is a schematic cross-sectional view and the lower part is a
schematic plan view of the microphone unit as viewed from above.
As shown in FIG. 1, the microphone unit 1 of the present embodiment includes a mounting
member 11, a MEMS (Micro Electro Mechanical System) chip 12 having a diaphragm 122, and
an application specific integrated circuit (ASIC) 13. There is.
The MEMS chip is an embodiment of the electroacoustic transducer of the present invention.
[0027]
The mounting member 11 is a member on which the MEMS chip 12 and the ASIC 13 are
mounted.
In this embodiment, the mounting member 11 is formed by bonding two substrates (members),
and it can be said that the mounting member 11 corresponds to the microphone substrate 101
shown in FIG.
FIG. 2 is a schematic plan view of the two substrates constituting the mounting member provided
in the microphone unit of the present embodiment as viewed from above, and FIG. 2A is a view of
the first substrate disposed on the upper side, It is a figure of the 2nd board ¦ substrate with
which 2 (b) is arrange ¦ positioned below.
[0028]
The first substrate 111 and the second substrate 112 constituting the mounting member 11 may
be formed using a substrate made of a known substrate material, and the material is not
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particularly limited.
However, those which can be obtained at low cost and have high rigidity are preferable. For
example, it is preferable to use FR-4 or BT resin (registered trademark).
The first substrate 111 and the second substrate 112 may be substrates made of different
materials, but are preferably substrates made of the same material having the same linear
expansion coefficient.
[0029]
As shown in FIG. 2A, in the first substrate 111 constituting the mounting member 11, two
through holes of a first through hole 111a and a second through hole 111b are formed. In the
microphone unit 1 of the present embodiment, the through hole 111a has a substantially circular
shape in a plan view, and the through hole 111b has a substantially rectangular shape in a plan
view. However, the present invention is not limited to these shapes. You may change the shape
of.
[0030]
As shown in FIG. 2B, a groove 112a having a substantially rectangular shape in a plan view is
formed on the second substrate 112 constituting the mounting member 11. The groove 112a is
provided at a position where it overlaps with the first through hole 111a and the second through
hole 111b when the first substrate 111 and the second substrate 112 are bonded.
[0031]
Further, in the groove 112a formed in the second substrate 112, two supporting portions 14
having substantially the same height as the depth of the groove 112a are provided. Both of these
two support portions 14 are provided to protrude with respect to the side wall of the groove
112a. The two support portions 14 are provided to face each other in the width direction W.
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[0032]
In the present embodiment, the support portion 14 is integrally formed with the second
substrate 112. For example, the groove 112a and the support portion 14 (two) can be formed by
scraping off the hatched portion in FIG. 2B of the second substrate 112 to a predetermined depth
by the router. However, the support portion 14 may be a separate member from the substrate
constituting the mounting member 11, and may be formed by bonding, for example, an epoxy
resin or the like to the bottom surface of the groove 112a.
[0033]
The first substrate 111 and the second substrate 112 are bonded, for example, by an epoxy resin
adhesive, an epoxy resin adhesive sheet, or the like. And thereby, as shown in FIG. 1, while the
1st opening 21 and the 2nd opening 22 are provided in the mounting surface 11a, the internal
space which connects the 1st opening 21 and the 2nd opening 22 ( The mounting member 11
provided with the substrate internal space 23 is obtained.
[0034]
In addition, when the first substrate 111 and the second substrate 112 are attached to each
other, the two support portions 14 are in contact with the lower surface of the first substrate
111. In other words, in the microphone unit 1, the two support portions 14 are held by the upper
wall 23 a and the lower wall 23 b (two opposing inner walls substantially parallel to the
mounting surface 11 a) of the internal space 23 of the mounting member 11 Provided in
[0035]
In the microphone unit 1 of the present embodiment, the first substrate 111 and the second
substrate 111 are arranged such that the entire two through holes 111a and 111b overlap the
grooves 112a in plan view in the direction substantially orthogonal to the mounting surface 11a.
And 112 are configured. The support portion 14 is provided to overlap the MEMS chip 12 in
plan view in a direction substantially orthogonal to the mounting surface 11 a.
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[0036]
Further, although not shown, various wires necessary for exhibiting the function of the
microphone unit 1 (function of converting the input sound into an electric signal and outputting
it) are formed on the first substrate 111 and the second substrate 112. It is done. An electrode
15 electrically connected to these wirings is provided on the lower surface 11 a of the mounting
member 11 (more specifically, the lower surface of the second substrate 112). The electrode 15
is used when the microphone unit 1 is mounted on the surface of a mounting substrate of a voice
input device (for example, a mobile phone), whereby supply of power to the microphone unit 1
or voice input from the microphone unit 1 is performed. It enables the output of signals to the
device.
[0037]
FIG. 3 is a schematic cross-sectional view showing the configuration of the MEMS chip provided
in the microphone unit of the present embodiment. As shown in FIG. 3, the MEMS chip 12
formed of a silicon chip has an insulating base substrate 121, a diaphragm 122, an insulating
layer 123, and a fixed electrode 124, and constitutes a capacitor type microphone. ing.
[0038]
The base substrate 121 is formed with an opening 121 a having a substantially circular shape in
plan view. The diaphragm 122 provided on the base substrate 121 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 124 is disposed to face the diaphragm 122 with the
insulating layer 123 interposed therebetween. Thereby, a capacitance is formed between the
diaphragm 122 and the fixed electrode 124. A plurality of sound holes 124 a are formed in the
fixed electrode 124 so that sound waves can pass therethrough.
[0039]
The MEMS chip 12 is configured to apply sound pressure from the upper surface 122 a and the
lower surface 122 b of the diaphragm 122. For this reason, the diaphragm 122 vibrates
according to the difference between the sound pressure pf applied from the upper surface 122 a
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and the sound pressure pb applied from the lower surface 122 b. When the diaphragm 123
vibrates, the distance Gp between the diaphragm 122 and the fixed electrode 124 changes, and
the capacitance between the diaphragm 122 and the fixed electrode 124 changes. As a result, the
sound wave (sound signal) incident on the MEMS chip 12 can be extracted as an electric signal.
[0040]
The configuration of the MEMS chip as the electroacoustic transducer is not limited to the
configuration of this embodiment. For example, in the present embodiment, the diaphragm 122
is lower than the fixed electrode 124, but it is configured such that the opposite relationship to
this (the diaphragm is upper and the fixed electrode is lower) It does not matter.
[0041]
In the microphone unit 1, the MEMS chip 12 is mounted on the mounting member 11 so that the
upper surface 122 a and the lower surface 122 b of the diaphragm 122 are substantially parallel
to the mounting surface 11 a of the mounting member 11 and covers the first opening 21. (See
Figure 1). The MEMS chip 12 is mounted by wire bonding in the present embodiment.
Specifically, the bottom surface of the MEMS chip 12 opposite to the mounting surface 11 a of
the mounting member 11 is joined by a die bonding material (for example, an adhesive of epoxy
resin type or silicone resin type) 16. By bonding in this manner, the sound does not leak from the
gap formed between the mounting surface 11 a of the mounting member 11 and the lower
surface of the MEMS chip 12. Also, the MEMS chip 12 is electrically connected to the ASIC 13 by
the wire 17.
[0042]
The ASIC 13 mounted on the mounting surface 11 a of the mounting member 11 is an integrated
circuit that amplifies an electrical signal extracted based on a change in capacitance of the MEMS
chip 12. The ASIC 13 functioning as the signal processing unit may be configured to include a
charge pump circuit and an operational amplifier so that a change in capacitance in the MEMS
chip 12 can be accurately obtained.
[0043]
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The ASIC 13 has a bottom surface facing the mounting surface 11 a of the mounting member 11
joined by the die bonding material 18. The electric signal amplified by the ASIC 13 is electrically
connected to an electrode formed on the mounting surface 11 a of the mounting member 11 by
a wire 19. Then, the electric signal amplified by the ASIC 13 can be output to the outside of the
microphone unit 1 by the wiring (including the through wiring) formed on the first substrate 111
and the second substrate 112 constituting the mounting member 11 ing.
[0044]
Although the MEMS chip 12 and the ASIC 13 are mounted by wire bonding in the above
description, the MEMS 12 and the ASIC 13 may of course be flip chip mounted. In the case of flip
chip mounting, the MEMS chip 12 has, for example, a frame-like connection pad (not shown)
formed so as to surround the first opening 21 of the mounting surface 11a and its lower surface
(lower surface of the MEMS chip 12) Are joined by, for example, solder or the like. As a result,
the sound does not leak from the gap formed between the mounting surface 11 a of the
mounting member 11 and the lower surface of the MEMS chip 12. Also, the MEMS chip 12 and
the ASIC 13 are electrically connected by the wiring formed inside the mounting member 11.
[0045]
Next, the operation and effect of the microphone unit 1 configured as described above will be
described.
[0046]
In the microphone unit 1, the sound wave passing through the sound hole 124 a of the fixed
electrode 124 from the upper side of the MEMS chip 12 is applied as the sound pressure to the
upper surface 122 a of the diaphragm 122.
On the other hand, to the lower surface 122 b of the diaphragm 122, a sound wave that is input
from the second opening 22 and passes through the inner space 23 and the first opening 21 in
this order is applied as a sound pressure.
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[0047]
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. For this
reason, in the case of the configuration as in this embodiment, the user's voice generated in the
vicinity of the microphone unit 1 and incident on both surfaces 122a and 122b of the diaphragm
122 is a loud sound by the upper surface 122a and the lower surface 122b of the diaphragm
122. A pressure difference is generated to vibrate the diaphragm. On the other hand, the noises
incident on the both surfaces 122a and 122b of the diaphragm 122 from a distance are almost
the same sound pressure and cancel each other to hardly vibrate the diaphragm.
[0048]
Therefore, the sound pressure for vibrating the diaphragm 122 can be regarded as the sound
pressure indicative of the user's voice, and the electrical signal obtained based on the vibration of
the diaphragm 122 has the user's voice from which the noise has been removed. It can be
regarded as an electrical signal to be shown. That is, the microphone unit 1 of the present
embodiment can convert only the target voice from which noise is removed into an electrical
signal and output it, which can be said to be a high quality microphone unit.
[0049]
Further, in the microphone unit 1 of the present embodiment, the surfaces 122 a and 122 b to
which the sound pressure of the diaphragm 122 is applied and the mounting surface 11 a on
which the MEMS chip 12 is mounted are substantially parallel. The space 23 is used as a sound
path. For this reason, it is possible to reduce the thickness of the microphone unit surfacemounted on the mounting substrate of the voice input device (for example, a mobile phone).
[0050]
Furthermore, in the microphone unit 1 of the present embodiment, the support portion 14 held
by the upper wall 23 a and the lower wall 23 b of the internal space 23 is provided in the
internal space 23 used as the above-described sound path. For this reason, even when the first
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substrate 111 constituting the mounting member 11 is thin (for example, about 0.2 mm or the
like), the bending of the first substrate 111 can be suppressed by the support portion 14.
[0051]
At the time of manufacturing the microphone unit 1, for example, when the MEMS chip 12 is
mounted on the mounting member 11 or when performing wire conditioning, a large force may
be applied to the mounting member 11 from the MEMS chip 12. In the microphone unit 1
according to the present embodiment, even if such a force is applied, the bending of the first
substrate 111 can be suppressed by the support portion 14.
[0052]
That is, according to the microphone unit 1 of the present embodiment, it is possible to suppress
that the internal space 23 formed in the mounting member 11 is narrowed due to the deflection
generated in a part of the mounting member 11, and defects in die bonding and wire bonding are
caused. It can be suppressed. Therefore, according to the microphone unit 1 of the present
embodiment, it is possible to reduce the thickness of the microphone unit while suppressing the
deterioration of the microphone characteristics.
[0053]
The microphone unit 1 shown above shows an example of the embodiment of the present
invention, and the scope of application of the present invention is not limited to 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.
[0054]
For example, in the embodiment described above, the two support portions 14 are provided in
the internal space 23 formed in the mounting member 11, but the number, shape, and
arrangement of the support portions 14 are the same as in this embodiment. The configuration is
not limited to the above, and may be changed as appropriate. The support portion 14 may be
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disposed so as to suppress the narrowing of the internal space 23 due to the deformation of the
mounting member 11. That is, for example, as shown in FIG. 4, the support portions 14 may be
arranged at four places. 4 is a schematic plan view for explaining another form of the support
portion provided in the inner space, which is similar to the lower view of FIG.
[0055]
Further, unlike the embodiment described above, for example, as shown in FIG. 5A, even if the
support portion 14 is formed at a position apart from the two side walls opposed in the width
direction W of the groove 112a. I do not care. In FIG. 5A, two rows of support portions 14 having
a substantially rectangular shape in plan view arranged three by three in the width direction W
are provided in the groove 112a. Further, for example, as shown in FIG. 5B, the width of the
groove 112a is narrowed in the portion corresponding to the lower portion of the MEMS chip 12
by making the size of the support portion 14 larger than in the embodiment shown above. The
support portion 14 may be provided so as to be wider at a portion corresponding to the lower
portion of the second opening 22. According to this configuration, it is possible to increase the
expectation of the following effects while securing the cross-sectional area of the sound path
from the lower part of the MEMS chip 12 to the lower part of the second opening 22 as wide as
possible. That is, when the MEMS chip 12 is die-bonded onto the mounting member 11 or when
wire bonding is performed, the MEMS chip 12 is pressed downward, and the portion of the
mounting member 11 directly below the MEMS chip 12 is bent. It is possible to effectively
prevent the occurrence of a bonding failure or a wire bonding failure. Further, by bending the
portion of the mounting member 11 directly below the MEMS chip 12, the internal space 23 is
compressed and narrowed, and the acoustic resistance is increased to effectively prevent the
microphone characteristic of the microphone unit 1 from being deteriorated. .
[0056]
In the embodiment described above, the mounting member 11 on which the MEMS chip 12 is
mounted is configured by bonding two substrates 111 and 112 together. However, the
configuration of the mounting member is not intended to be limited to this configuration. For
example, the mounting member may be formed of three or more substrates, and in some cases,
the mounting member may be formed of one substrate. Also, the mounting member may be
configured by combining a plurality of members having different properties, such as a
combination of a substrate and a resin molded member.
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[0057]
FIG. 6 is a view showing an example of the configuration of a resin molded member when the
mounting member is configured using a substrate and a resin molded member, and FIG. 6 (a) is a
schematic plan view when the resin molded member is viewed from above Fig. 6 (b) is a
schematic cross-sectional view taken along the line A-A of Fig. 6 (a). In addition, in this case, the
board ¦ substrate which comprises a mounting member is the structure similar to the 1st board ¦
substrate 111 in embodiment mentioned above.
[0058]
The resin molding member 113 constituting the mounting member is formed in a box shape
having the housing recess 113a. The mounting member is formed by fitting the first substrate
111 (see FIG. 2A) into the housing recess 113a. A groove 113 b having a substantially
rectangular shape in plan view is formed on the bottom surface of the housing recess 113 a of
the resin molding member 113. Thus, as in the case where the first substrate 111 and the second
substrate 112 are bonded to each other, the first opening 111 is communicated with the second
opening by fitting the first substrate 111 into the resin forming member 113. Internal space is
obtained.
[0059]
Further, in the groove 113b of the resin forming member 113, there is formed a supporting
portion 14 integrally formed with the resin forming member 113 or by bonding another
member, thereby the same as the embodiment described above. An effect is obtained. Further,
although not shown, in the resin molding member 113, an electrode connected to the connection
terminal of the mounting substrate is formed by, for example, insert molding.
[0060]
In addition, although the material which comprises the resin molding member 113 is not
specifically limited, For example, resin, such as LCP (Liquid Crystal Polymer; liquid crystal
polymer) and PPS (polyphenylene sulfide; polyphenylene sulfide), is used.
[0061]
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In the embodiment described above, although the microphone unit does not include the lid, the
present invention is also applicable to the case where the microphone unit includes the lid.
FIG. 7 is a view showing a modification of the microphone unit of the present embodiment, and is
a view showing a configuration in the case where the microphone unit is provided with a lid. The
microphone unit 2 shown in FIG. 7 is the same as the microphone unit 1 shown in FIG. 1 except
that a lid 30 is provided. For this reason, the same reference numerals are given to parts
overlapping with the configuration of FIG.
[0062]
The lid 30 has a substantially rectangular parallelepiped outer shape, and includes a first space
301 and a second space 302 separated from the first space 301. The lid 30 is mounted on the
mounting member 11 such that the first space 301 is separated by the MEMS chip 12 from the
internal space 23 (which is a space formed in the mounting member 11). The lid 30 is mounted
on the mounting member 11 such that the second space 302 communicates with the internal
space 23 through the second opening 22.
[0063]
The upper surface 122 a of the diaphragm 122 is in communication with the outside through the
first space 301 and the first sound hole 31 provided in the lid 30. The lower surface 122 b of the
diaphragm 122 communicates with the outside through the first opening 21, the inner space 23,
the second opening 22, the second space 302, and the second sound hole 32 provided in the lid
30. . That is, the microphone unit 2 has a sound path for guiding an external sound to the upper
surface 122a of the diaphragm 122 and a sound path for guiding an external sound to the lower
surface 122b of the diaphragm 122, as shown in FIG. Like the microphone unit 1 shown in FIG.
1, the microphone unit 2 is also a differential type microphone unit.
[0064]
In the embodiment described above, the MEMS chip 12 and the ASIC 13 are formed as separate
chips, but the integrated circuit mounted on the ASIC 13 is monolithically formed on the silicon
substrate on which the MEMS chip 12 is formed. I don't care.
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[0065]
In the embodiment described above, the electro-acoustic conversion unit for converting the
sound pressure into the electric signal is the MEMS chip 12 formed using a semiconductor
manufacturing technology, but 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.
[0066]
Moreover, in the above embodiment, a so-called condenser type microphone is adopted as the
configuration of the electroacoustic transducer (corresponding to the MEMS chip 12 of the
present 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.
[0067]
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.
[0068]
1, 2 microphone unit 11 mounting member 11a mounting surface 12 MEMS chip (electroacoustic transducer) 14 support portion 21 first opening 22 second opening 23 internal space
23a upper wall (inner wall of internal space) 23b lower wall (internal Inner wall of space) 30 lid
31 first sound hole 32 second sound hole 111 first substrate (part of mounting member) 112
second substrate (part of mounting member) 113 resin molded member (part of mounting
member) 122 diaphragm 122a upper surface of diaphragm (one surface of diaphragm) 122b
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lower surface of diaphragm (other surface of diaphragm) 301 first space 302 second space
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