close

Вход

Забыли?

вход по аккаунту

JP2007124306

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 JP2007124306
PROBLEM TO BE SOLVED: To eliminate the need for securing a space for a microphone unit in an
apparatus including an information display device mounted with a microphone, to improve the
degree of freedom in designing the apparatus and to promote the miniaturization of the
apparatus. . SOLUTION: A microphone element 10 has a fixed electrode 5a provided to form a
capacitor by a combination of a glass substrate 7, a vibrating electrode 6a provided on the glass
substrate 7, and a vibrating electrode 6a, and a fixed electrode. When the vibrating electrode 6a
vibrates due to the sound pressure entering through the sound hole 1 provided in the 5a, the
output units 3 and 4 output the change in capacitance of the capacitor due to the vibration as an
audio signal. The glass substrate 7 constituting the microphone element 10, the vibrating
electrode 6a, the fixed electrode 5a, and the output parts 3 and 4 are made of members that
transmit visible light. The microphone element 10 is placed on the information display screen of
the information display device 100. [Selected figure] Figure 3
Information display device
[0001]
The present invention relates to an information display apparatus, and more particularly to an
information display apparatus equipped with a microphone element that transmits visible light.
[0002]
Conventionally, a microphone (acoustic sensor) is known which vibrates a diaphragm
(diaphragm) by sound and picks up an electrical signal corresponding to the sound based on a
change in the vibration (for example, Patent Document 1).
04-05-2019
1
[0003]
FIG. 17 is a view showing a schematic configuration of the microphone disclosed in Patent
Document 1 above.
The microphone disclosed in this patent document is, as shown in FIG. 17, a diaphragm 51 made
of SiN on a substrate 50 made of silicon, an electrode 52a made of metal disposed at an end of
the diaphragm 51, and its electrodes And an electrode 52b disposed at a predetermined interval
so as to face 52a.
Then, when the diaphragm 51 is vibrated by sound, the vibration of the diaphragm 51 also
vibrates the electrode 52 a disposed at the end of the diaphragm 51. As a result, the interelectrode distance between the electrode 52a and the electrode 52b changes, so the capacitance
of the capacitor formed of the electrodes 52a and 52b changes. As a result, since the potential of
the electrode 52b changes, the change of the potential is output as an electrical signal
corresponding to the sound. Patent No. 3556676 gazette
[0004]
However, in the microphone of the prior art, since the substrate 50 made of silicon and the
electrodes 52a and 52b made of metal are not respectively made of members capable of
transmitting visible light, a space is required when mounted on a small information device such
as a mobile phone. It becomes a factor that inhibits the degree of freedom in design for securing
and the miniaturization of equipment.
[0005]
The present invention has been made in view of the above circumstances, and an object of the
present invention is to install a microphone element transmitting visible light on an information
display screen and to design an apparatus including the information display screen with a degree
of freedom of design. Improve and promote the miniaturization of equipment.
[0006]
The information display device according to claim 1 is provided on a fixed electrode provided to
form a capacitor by combining a substrate, a movable electrode provided on the substrate, and a
movable electrode, and provided on the fixed electrode. A microphone element including an
04-05-2019
2
output section for outputting, as an audio signal, a change in capacitance of the capacitor due to
vibration when the movable electrode vibrates due to the sound pressure entering through the
sound hole, the substrate, the movable electrode and the fixed An electrode and an output part
are comprised by the member which permeate ¦ transmits visible light, and it makes it the
summary to have installed the microphone element on the information display screen.
[0007]
That is, since the substrate that constitutes the microphone element, the movable electrode, the
fixed electrode, and the output portion transmit visible light, the information display device can
be installed on the surface on which information is displayed, so information display can be
performed. It is not necessary to secure a space for the microphone unit in the device including
the device, and the degree of freedom in design can be improved and the miniaturization of the
device can be promoted.
[0008]
The information display apparatus according to claim 2 includes a substrate, a movable electrode
provided on the substrate, an electrode of a piezoelectric material capable of generating power
by being vibrated together with the movable electrode, an electrode and a piezoelectric material
movable by sound pressure A microphone element including an output unit for outputting, as an
audio signal, a change in voltage generated by a strain generated in the electrode of the
piezoelectric body when the electrode of the electrode vibrates, the substrate, the movable
electrode, the electrode of the piezoelectric body and the output portion The gist is that the
microphone element is disposed on the information display screen as well as a member that
transmits visible light.
[0009]
That is, since the substrate that constitutes the microphone element, the movable electrode, the
fixed electrode, and the output portion transmit visible light, the information display device can
be installed on the surface on which information is displayed, so information display can be
performed. It is not necessary to secure a space for the microphone unit in the device including
the device, and the degree of freedom in design can be improved and the miniaturization of the
device can be promoted.
[0010]
An information display apparatus according to a third aspect of the present invention is
configured as an array using a plurality of the microphone elements according to the first aspect
or the second aspect, and is disposed on an information display screen.
04-05-2019
3
[0011]
That is, when microphone elements transmitting visible light are installed on the information
display screen, the directivity of the sound pickup can be controlled by forming a plurality of
microphone elements into an array.
[0012]
According to the present invention, it is possible to provide an information display device
equipped with a microphone element that transmits visible light.
[0013]
Hereinafter, the best mode for carrying out the present invention will be described in detail.
[0014]
First Embodiment FIG. 1 is a top view of a microphone element 10 according to an embodiment
of the present invention.
The surface of the microphone element 10 is covered with a protective film 2 and has a plurality
of minute acoustic holes 1.
The sound pressure that has passed through the acoustic hole 1 is converted into a signal of
capacitance change using a capacitance detection mechanism formed in the microphone element
10 described later, and the signal of capacitance change is for the vibrating electrode It is
outputted by the terminals of the pad electrode 3 and the fixed electrode pad electrode 4.
The output capacitance change signal is output by, for example, a speaker, or converted into a
digital signal and stored.
[0015]
04-05-2019
4
FIG. 2 shows a state in which the protective film 2 is removed and the interlayer film 12 is locally
removed in order to explain the internal structure of the microphone element 10 of FIG.
The fixed electrode 5a is connected to the fixed electrode pad electrode 4 via the fixed electrode
lead wiring portion 5b integral with the fixed electrode 5a.
Under the fixed electrode 5a, a vibrating electrode 6a (see FIG. 3) described later is provided via
a gap, and the vibrating electrode 6a and the fixed portion 6b of the vibrating electrode are
integrated.
The fixed portion 6b of the vibrating electrode is connected to the vibrating electrode pad
electrode 3 via the vibrating electrode lead wiring portion 6c integral with the fixed portion 6b of
the vibrating electrode.
The fixed portion 6b of the vibrating electrode has a recess 6d as shown by a dotted line.
[0016]
A cross-sectional view between AB in FIGS. 1 and 2 is shown in FIG. 3, and a cross-sectional view
between CD is shown in FIG.
[0017]
In FIG. 3, an interlayer film 9 having a void 8 which is an opening is formed on a glass substrate
7.
The vibrating electrode 6a provided so as to cover the air gap 8 is fixed on the interlayer film 9
by the fixing portion 6b of the vibrating electrode which is integral therewith, and the vibrating
electrode 6a via the vibrating electrode lead wiring portion 6c which is integral therewith. It is
connected to the pad electrode 3.
An interlayer film 12 is formed on the fixed portion 6 b of the vibrating electrode, and the
interlayer film 12 has an air gap 11.
04-05-2019
5
A protective film 2 is coated thereon, and a fixed electrode 5a provided with an acoustic hole 1 is
formed.
The fixed electrode 5a and the vibrating electrode 6a constitute a capacitor, and the change in
the sound pressure introduced from the acoustic hole 1 is converted into the change in
capacitance of the capacitor, and the signal of the capacitance change is used for the vibrating
electrode The pad electrode 3 and the fixed electrode pad 4 are output as terminals.
[0018]
FIG. 4 shows a cross-sectional view between CD in FIG. 1 and FIG. The recess 6d of the vibrating
electrode in FIG. 2 corresponds to the opening 13 of the vibrating electrode in FIG. A wet etching
solution introduced from an acoustic hole 1 described later forms a void 11 and passes through
the opening 13 to form a void 8.
[0019]
The glass substrate 7 is the substrate of the present invention, the vibrating electrode 6 a is
the movable electrode of the present invention, the fixed electrode 5 a is the fixed
electrode of the present invention, and the acoustic hole 1 is the sound of the present
invention. The hole , the vibrating electrode pad electrode 3 and the fixed electrode pad
electrode 4 are examples of the output portion in the present invention.
[0020]
Hereinafter, the structure of the microphone element shown in FIG. 3 will be described with
reference to FIGS. 5 to 8 showing a manufacturing process.
[0021]
First step (see FIG. 5A): 3 μm of silicon nitride (SiN) is formed on the glass substrate 7 as the
interlayer film 9 by plasma CVD method using monosilane or dichlorosilane as a source gas,
photolithography technology and The silicon nitride is patterned using an etching technique.
04-05-2019
6
After this, for example, a 10 μm thick phosphorus-doped silicon oxide film (PSG) is formed on
the surface by plasma CVD or atmospheric pressure CVD, and phosphorus is added to the silicon
nitride surface by CMP (chemical mechanical polishing). The silicon oxide film is removed, the
phosphorus-doped silicon oxide film is left only in the opening of the silicon nitride film, and the
sacrificial layer 14 is formed.
Although a silicon oxide film containing phosphorus (P) is generally used for the sacrificial layer,
any film may be used as long as it is soluble in hydrofluoric acid (HF). This sacrificial layer is a
layer which does not remain in the final structure because it is removed later by etching with HF.
Since the thickness of the sacrificial layer is the final air gap distance between the electrodes, the
capacitance (C = e * S / t, e: dielectric constant, S: electrode area, t: air gap distance), that is,
sensitivity While being reflected, the rigidity of the structure of the acoustic sensor 100 is also
greatly affected.
[0022]
Second step (see FIG. 5B): A 0.5 to 1 μm thick polysilicon film (Poly-Si) of a high elastic modulus
film is formed by Low Pressure-CVD (hereinafter LP-CVD), The vibrating electrode 6a and the
fixed portion 6b and the lead-out wiring portion 6c integral therewith are formed using the
lithography technology and the etching technology. For the vibrating electrode, polysilicon is
generally used, but other conductive materials may be used.
[0023]
Third step (see FIG. 5 (c)): For example, a phosphorus-added silicon oxide film (PSG) is formed 3
μm thick on the surface by plasma CVD or atmospheric pressure CVD, and vibration is
generated by photolithography and etching. A sacrificial layer 15 is formed on the sacrificial
layer 14 via the electrode 6a.
[0024]
Fourth step (see FIG. 6D): A silicon nitride film of 10 μm is formed thereon by plasma CVD, and
silicon nitride films other than the surface of the phosphorus-doped silicon oxide film are
similarly removed by CMP. To form an interlayer film 12.
[0025]
04-05-2019
7
Fifth step (see FIG. 6E): An indium tin oxide film (hereinafter referred to as ITO film) is formed to
a thickness of 1 μm as a transparent electrode film by a sputtering method, and the fixed
electrode 5a is formed using photolithography technology and etching technology. Form.
At this time, lead wires (not shown) for fixed electrodes are also formed at the same time.
[0026]
Sixth step (see FIG. 7F): In order to suppress deterioration of the ITO film, a protective film of SiN
is formed to a thickness of 1 μm on the surface by a low temperature sputtering method at 100
° C. or less.
Further, an opening 16 for the acoustic hole 1 and the pad electrode 3 for the vibrating electrode
(see FIG. 3) is formed by using a photolithography technique and an etching technique. The
acoustic hole 1 has a function of passing an air when sound enters.
[0027]
Seventh step (see FIG. 7G): The upper and lower sacrificial layers 14 and 15 of the vibrating film
are removed via the acoustic hole 1 by wet etching using hydrofluoric acid (HF) to form the gaps
8 and 11 .
[0028]
Eighth step (see FIG. 8 (h)): 1 μm of ITO film is deposited by sputtering, and the pad electrode 3
for vibrating electrode is formed by a step using photolithography technology and etching
technology. It will be completed.
[0029]
FIG. 9 shows an information display apparatus in which the microphone element 10 completed
by the above steps is attached, for example, on an information display screen 40 such as a
display unit of a car navigation system using a double-sided adhesive film of polyethylene
terephthalate material of high transparency type. It shows 100.
04-05-2019
8
[0030]
The operation and effects of the first embodiment will be described below.
[0031]
The microphone element 10 according to the present embodiment includes the glass substrate 7,
the silicon nitride of the interlayer films 9 and 12, the polysilicon of the vibrating electrode 6a,
the ITO of the fixed electrode 5a, and the pad electrode 3 for the vibrating electrode, as shown in
FIG. A film is a constituent element, and each constituent element is characterized by
transmitting visible light. Therefore, by using a double-sided adhesive film or the like of a highly
transparent type polyethylene terephthalate material, the information display screen 40 of the
information display device 100 is obtained. It can be installed anywhere.
As a result, there is no need to secure a space for mounting the microphone in the device
including the information display device 100, the degree of freedom in design can be improved,
and the miniaturization of the device can be promoted.
[0032]
Second Embodiment An embodiment of a microphone element using a piezoelectric body will be
described below.
[0033]
FIG. 10 is a view of the microphone element 20 according to the embodiment of the present
invention as viewed from the top side provided with the upper electrode 21a.
The upper electrode 21a is connected to the upper electrode pad electrode 4 through the upper
electrode lead wiring portion 21b.
The fixed portion 6b of the vibrating electrode has the piezoelectric film 22 provided between it
and the upper electrode 21a inserted, and is connected to the vibrating electrode pad electrode 3
via the vibrating electrode lead wiring portion 6c.
04-05-2019
9
Further, since the fixed portion 6b of the vibrating electrode is provided with the recess 6d, the
fixing electrode 6b has the opening 24 of the vibrating electrode.
Here, a cross-sectional view between AB in FIG. 10 is shown in FIG. 11 for easy understanding of
the structure, and a cross-sectional view between CD is shown in FIG.
[0034]
In FIG. 11, a piezoelectric film 22 made of a piezoelectric material is formed so as to be inserted
into the upper electrode 21 and the vibrating electrode 6a formed in the lower layer thereof. The
upper electrode 21a is connected to the upper electrode pad electrode 23 through the upper
electrode lead wiring portion 21b integral with the upper electrode 21a. The vibrating electrode
6a is fixed on the lower layer interlayer by the fixing portion 6b integral with the vibrating
electrode 6a, and further connected to the vibrating electrode pad electrode 3 through the
vibrating electrode lead wiring portion 6c integral with the vibrating electrode 6a. ing.
[0035]
Here, when the vibrating electrode 6a vibrates, distortion occurs in the piezoelectric film 22
provided on the vibrating electrode 6a, and a voltage is generated between the upper and lower
sides of the piezoelectric film 22 in response to the change in the distortion. By measuring the
change of this voltage between the terminals of the vibrating film pad electrode 3 and the upper
electrode pad electrode 23, the change of the sound pressure is read.
[0036]
FIG. 12 shows a cross-sectional view between CDs in FIG. The opening 24 of the vibrating
electrode formed by providing the recess 6 d (see FIG. 10) of the vibrating electrode corresponds
to the opening 13 of the vibrating electrode of FIG. 12. A wet etching solution described later
passes through the opening 13 to form a void 8.
04-05-2019
10
[0037]
The glass substrate 7 is the substrate of the present invention, the vibrating electrode 6 a is
the movable electrode of the present invention, the piezoelectric film 22 is the
piezoelectric electrode of the present invention , the vibrating electrode pad electrode 3 and
the upper portion The electrode pad electrode 23 is an example of the output unit in the
present invention.
[0038]
Hereinafter, the structure of the microphone element shown in FIG. 11 will be described with
reference to FIGS. 13 and 14 showing a manufacturing process.
[0039]
First step (see FIG. 13A): On the glass substrate 7, a silicon nitride film (SiN) of 3 μm is formed
as the interlayer film 9 by plasma CVD.
After patterning the interlayer film using photolithography technology and etching technology, a
10 μm thick phosphorus-doped silicon oxide film (PSG) is formed on the surface as a sacrificial
layer 14 by plasma CVD method or atmospheric pressure CVD method, and CMP method is used.
The phosphorus-doped silicon oxide film is removed by 7 μm.
[0040]
Second step (see FIG. 13B): A polysilicon film (Poly-Si) is formed to a thickness of 0.5 to 1 μm by
a low pressure CVD method, and using the photolithography technology and the etching
technology, the vibrating electrode 6a and the fixing portion 6b and the lead-out wiring portion
6c are formed.
[0041]
Third step (see FIG. 13C): A piezoelectric film (PZT, Pb (Zr, Ti) O3) is deposited on a surface of 1
μm by CVD, and thermal annealing is performed for 30 minutes at 650 ° C. After performing
the process of (4), the piezoelectric film 22 is formed on the upper surface of the vibrating film
using photolithography technology and etching technology.
[0042]
04-05-2019
11
Fourth step (see FIG. 14D): A transparent electrode film (ITO) is formed to a thickness of 1 μm
on the surface by sputtering, and the upper electrode 21 and the lead-out wiring on the
piezoelectric film are formed using photolithography and etching techniques. (Not shown) and a
pad electrode 3 for vibrating electrode are formed.
[0043]
Fifth step (see FIG. 14E): The sacrificial layer 14 is removed by wet etching using hydrofluoric
acid through an opening 13 (see FIG. 11) provided in a part of the vibrating film on the sacrificial
layer. The air gap 8 is formed, and the microphone element of the present embodiment is
completed.
[0044]
When the microphone element 10 of FIG. 9 is replaced with the microphone element 20, the
same figure shows the microphone element 20, for example, a double-sided adhesive film of a
highly transparent polyethylene terephthalate material on an information display screen 40 such
as a display unit of a car navigation system. The information display apparatus 100 attached
using is shown.
[0045]
The operation and effects of the second embodiment will be described below.
[0046]
The microphone element 20 according to this embodiment includes the glass substrate 7, silicon
nitride of the interlayer film 9, polysilicon of the vibrating electrode 6a, PZT of the piezoelectric
film 22, and the ITO film of the upper electrode 21 and the pad electrode 3 for the vibrating
electrode. Since each component is characterized in that it transmits visible light, it can be
installed anywhere on the information display surface of the information display device by using
a double-sided adhesive film of a highly transparent type polyethylene terephthalate material or
the like. Can.
As a result, there is no need to secure a space for mounting a microphone in an apparatus
including an information display device, the degree of freedom in design can be improved, and
downsizing of the apparatus can be promoted.
04-05-2019
12
[0047]
Third Embodiment Hereinafter, an embodiment of an information display device in which a
plurality of microphone elements of the present invention are mounted in an array form will be
described.
[0048]
FIG. 15 shows an information display device 100 arranged in an array on the display 40 of the
information display device using a plurality of microphone elements 30 of the present invention.
The microphone element 30 is the microphone element 10 of the first embodiment (see FIG. 1)
or the microphone element 20 of the second embodiment (see FIG. 10).
The microphone element 30 of the present invention can be installed at an arbitrary place on the
information display screen 40 of the information display device 100 because of the property of
transmitting visible light, and it is necessary to secure the space of the microphone part in the
apparatus including the information display device 100. It is possible to improve the degree of
freedom of design by eliminating the gender.
Here, it is assumed that the display 40 and the microphone element 30 are square, the same
number of microphone elements are installed on each side of the display, and the intervals
between the nearest microphone elements are uniform.
Further, the number of microphone elements installed on one side of the display 40 is M, and the
distance between the nearest microphone elements is d (mm).
[0049]
Here, as shown in the equation (1), π is π, f is the frequency of sound (Hz), θ is the directivity
angle (°) with respect to the vertical direction of the display surface, and c is the speed of sound
(340000 mm / sec) , Characteristic factor Ω can be derived.
[0050]
04-05-2019
13
[0051]
Further, as shown in the equation (2), it is possible to derive a function G (θ) indicating the
directivity strength by using this characteristic factor Ω and the number M of microphone
elements on one side.
[0052]
[0053]
FIG. 16 (a) shows the directivity in the case where the number M of microphones is 10 and the
microphone spacing d is 35 mm using the above equations (1) and (2).
Here, the vertical axis represents directivity intensity G (θ), and the horizontal axis represents
directivity angle θ (°) with respect to the vertical direction of the display surface.
Further, FIG. 16 (b) shows directivity characteristics in the case where the number of
microphones is 3 and the distance between the microphones is 174 mm.
[0054]
The operation and effects of the third embodiment will be described below.
[0055]
As shown in FIGS. 16A and 16B, the directivity characteristic of the microphone can be
controlled by changing the number of microphones and the distance between the microphones in
the same length area as one side of the display.
That is, the directivity of the sound pickup can be arbitrarily controlled by the number of
microphone elements, the installation place, and the installation interval.
04-05-2019
14
[0056]
It should be understood that the embodiments disclosed herein are illustrative and nonrestrictive in every respect.
The scope of the present invention is indicated not by the description of the embodiments
described above but by the claims, and further includes all modifications within the meaning and
scope equivalent to the claims.
[0057]
Modifications within the scope of the claims in the above embodiment are exemplified below as
modifications.
[0058]
(First Modification) Although a glass substrate is used as a substrate transmitting visible light in
the present embodiment, the present invention is not limited to this, and, for example, a quartz
substrate is also applicable.
[0059]
Second Modification In the present embodiment, silicon nitride (SiN) is used as the interlayer film
and protective film transmitting visible light, but the present invention is not limited to this, for
example, silicon carbide (SiC) or silicon oxide It is also possible to apply SiOC or the like to which
carbon is added.
[0060]
(Third Modification) In this embodiment, Indium Tin Oxide (ITO) is used as the fixed electrode
and pad electrode transmitting visible light, but the present invention is not limited to this, for
example, SnO2, Indium Zinc Oxide (IZO), etc. Is also applicable.
[0061]
Fourth Modification In the present embodiment, PZT and Pb (Zr, Ti) O3 are used as a
piezoelectric material that transmits visible light, but the present invention is not limited to this,
and for example, AIN, ZnO, etc. may be applied. .
04-05-2019
15
[0062]
Fifth Modification In the present embodiment, a microphone structure is formed on a substrate
to produce a microphone element, and the microphone element is placed on the information
display screen of the information display device, but the present invention is not limited to this.
The microphone structure may be formed on a protective film or the like provided on the
information display screen of the information display device, which transmits visible light as a
substrate.
[0063]
(Sixth Modified Example) Although the display unit of the car navigation system is used as the
information display screen on which the microphone element is mounted in the present
embodiment, the present invention is not limited thereto. For example, the display unit of a
mobile phone or the display unit of a digital camera The microphone element of the present
invention may be installed on an information display screen mounted on a small device such as a
liquid crystal display and an information display screen mounted on a relatively large device such
as an LCD display or a CRT display used for a television.
[0064]
Sixth Modification In the present embodiment, a double-sided adhesive film of polyethylene
terephthalate material is used when installing the microphone element on the information
display screen of the information display device, but the present invention is not limited to this.
An adhesive film may be used.
[0065]
FIG. 5 is a top view of a microphone element according to an embodiment of the present
invention.
FIG. 5 is a top view of a microphone element according to an embodiment of the present
invention.
FIG. 5 is a cross-sectional view of a microphone element according to an embodiment of the
present invention.
04-05-2019
16
FIG. 5 is a cross-sectional view of a microphone element according to an embodiment of the
present invention.
FIG. 6 is a view showing a manufacturing process of the microphone element according to the
embodiment shown in FIG. 3;
FIG. 6 is a view showing a manufacturing process of the microphone element according to the
embodiment shown in FIG. 3;
FIG. 6 is a view showing a manufacturing process of the microphone element according to the
embodiment shown in FIG. 3;
FIG. 6 is a view showing a manufacturing process of the microphone element according to the
embodiment shown in FIG. 3;
FIG. 1 is a diagram of an information display device according to an embodiment of the present
invention.
FIG. 5 is a top view of a microphone element according to an embodiment of the present
invention.
FIG. 5 is a cross-sectional view of a microphone element according to an embodiment of the
present invention.
FIG. 5 is a cross-sectional view of a microphone element according to an embodiment of the
present invention.
FIG. 12 is a view showing a manufacturing process of the microphone element according to the
embodiment shown in FIG. 11; FIG. 12 is a view showing a manufacturing process of the
microphone element according to the embodiment shown in FIG. 11; FIG. 1 is a diagram of an
04-05-2019
17
information display according to an embodiment of the present invention. It is an equation that
derives the directivity strength as a function of the directivity angle. It is sectional drawing of the
silicon microphone of a prior art example.
Explanation of sign
[0066]
Reference Signs List 1 acoustic hole 2 protective film 3 pad electrode for vibration electrode 4
pad electrode for fixed electrode 5a fixed electrode 5b lead wiring portion for fixed electrode 6a
vibration electrode 6b fixed portion for vibration electrode 6c lead wiring portion for vibration
electrode 7 glass substrate
04-05-2019
18
1/--страниц
Пожаловаться на содержимое документа