JP2009147470A - Condenser microphone and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a condenser microphone that reduces a portion protruding from a substrate to be mounted in height by reducing a gap between a circuit board and a condenser portion, and to provide an electronic apparatus with the condenser microphone. <P>SOLUTION: The condenser microphone 1 mounted on an equipment substrate 121 includes: a condenser portion 4 having a vibration film 6 vibrating by sound waves and a back electrode plate 5 disposed opposite to the vibration film 6; a microphone substrate 8 having a through-hole 15; a field effect transistor 10 mounted on the surface of the microphone substrate 8 which is opposite to a surface facing the condenser portion 4; and an electrostatic shielding member 25 attached on the microphone substrate 8 and covering the field effect transistor 10 and the through-hole 15. The field effect transistor 10 and the electrostatic shielding member 25 are inserted into an opening 121a formed on the equipment substrate 121. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a condenser microphone having a converter such as a field effect transistor, and an electronic device such as a mobile phone terminal and a video camera provided with the condenser microphone.

  A condenser microphone is known as a microphone mounted on an electronic device such as a mobile phone terminal or a video camera. In recent years, there has been a strong demand for downsizing and thinning electronic devices such as mobile phone terminals on which a condenser microphone is mounted, and accordingly, thinning of the condenser microphone is also required.

  As a conventional condenser microphone of this type, for example, there is one described in Patent Document 1. Patent Document 1 describes an ultra-thin condenser microphone that can greatly improve the mass productivity and quality of a product. The ultra-thin condenser microphone described in Patent Document 1 includes a “cylindrical case in which a series of sound wave inlets are formed, and a disk mounted on the case and vibrated by sound waves input through the sound wave inlets. A diaphragm having a shape, a disk-shaped dielectric plate that holds a gap of a certain size from the diaphragm when mounted on the case, a first base ring that supports the dielectric plate, and the first base A second base ring that comes into contact with the inner wall of the case while wrapping around the ring, and is mounted on the case and includes a series of electrical patterns, and is in electrical contact with the first base ring, A PCB having a back chamber defined by the first base ring between the dielectric plate and a fixed size between the first base ring and the second base ring. Cap is characterized in that "is formed.

According to the ultra-thin condenser microphone described in Patent Document 1 having such a configuration, “the dielectric plate and the base ring do not suffer any damage such as deformation and damage caused by the press-fitting process. A diaphragm, a dielectric plate, and the like arranged in the structure can be expected to have a strict balance (see paragraph [0047]).
JP-T-2004-516725

  In the conventional condenser microphone as described in Patent Document 1, the height (thickness) is determined by the height of the field effect transistor housed in the case. FIG. 9 shows a cross-sectional view of a conventional condenser microphone equipped with a field effect transistor. The condenser microphone 301 has a case 302 that forms an exterior part. A plurality of sound passage holes 302 a for allowing sound waves to pass through are provided on one surface of the case 302, and an opening window 302 b is provided on the other surface facing the one surface of the case 302.

  Inside the case 302, a capacitor part 304 formed by the back electrode plate 305 and the vibration film 306, etc., a mesh member 307 interposed between the back electrode plate 305 of the capacitor part 304 and the inner surface of the case 302, A microphone substrate 308 disposed at a predetermined distance from the vibration film 306, a conductive member 309 that electrically connects the vibration film 306 and the microphone substrate 308, and a surface of the microphone substrate 308 on the vibration film 306 side The field effect transistor 310 and the like to be mounted are housed. The surface of the microphone substrate 308 opposite to the surface on which the field effect transistor 310 is mounted is exposed from the opening window 302b of the case 302.

  However, in the conventional condenser microphone 301, the field effect transistor 310 is mounted on the surface of the microphone substrate 308 on the condenser portion 304 side. For this reason, a gap in consideration of at least the height of the field effect transistor 310 is required between the microphone substrate 308 and the capacitor unit 304, which hinders a reduction in the thickness of the microphone.

  An object of the present invention is to provide a condenser microphone that can reduce the height of a portion protruding from a substrate to be mounted by reducing the gap generated between the circuit board and the capacitor portion in consideration of the above-described problems, and the same. An object is to provide an electronic device including a condenser microphone.

  The condenser microphone of the present invention is a condenser microphone mounted on a device substrate provided in an electronic device. The condenser microphone includes a capacitor part having a vibration film that vibrates by sound waves and a back electrode plate disposed to face the vibration film, a microphone substrate having a through-hole facing the capacitor part, and a microphone substrate. A transducer mounted on a surface opposite to the surface facing the capacitor portion and impedance-converting a change in capacitance of the capacitor portion; an electrostatic shield member attached to the microphone substrate and covering the transducer and the through hole; It is equipped with. The converter and the electrostatic shield member are most characterized by being inserted into an opening provided in the device substrate.

  An electronic device according to the present invention includes a device housing having a sound collection hole through which sound waves pass, a device board disposed in the device housing and having an opening, and mounted on the device board and the device housing. A condenser microphone facing the sound collection hole of the body. A capacitor microphone of this electronic device includes a capacitor part having a vibration film that vibrates by sound waves and a back electrode plate disposed to face the vibration film, a microphone substrate having a through hole facing the capacitor part, and a microphone. Mounted on the surface opposite to the capacitor portion of the circuit board for the capacitor, and converts the capacitance of the capacitor section to impedance conversion, and is mounted on the microphone substrate and electrostatically covers the converter and the through hole. And a shield member. And a converter and an electrostatic shielding member are inserted in the opening part of the board | substrate for apparatuses, It is characterized by the above-mentioned.

  According to the condenser microphone and the electronic apparatus of the present invention, the gap between the circuit board and the capacitor unit can be reduced, and the height protruding from the board is reduced when mounted on the board of the electronic apparatus. be able to. As a result, it is possible to reduce the size and thickness of a device including a microphone.

  Hereinafter, the best mode for carrying out the condenser microphone and the electronic apparatus of the present invention will be described with reference to the drawings, but the present invention is not limited to the following mode.

  FIG. 1 is a perspective view of a first embodiment of a condenser microphone according to the present invention as viewed from above, FIG. 2 is a perspective view of the same as seen from below, and FIG. 3 illustrates a state where an electrostatic shield member is removed from the condenser microphone. It is explanatory drawing.

  As shown in FIGS. 1 and 2, the condenser microphone 1 showing the first embodiment of the present invention has a case 2 that forms an exterior part. The case 2 is made of a metal member such as brass and has a bottomed cylindrical body closed on one side. A plurality of (four in the present embodiment) case-side sound passage holes 2a through which sound waves pass are provided in the upper surface plate 2A on the closed side of the case 2. Further, the opening facing the upper surface plate 2A is an opening window 2b through which a microphone substrate 8 described later is exposed.

  3A is a plan view of the condenser microphone 1, and FIG. 3B is a cross-sectional view taken along line XX shown in FIG. 3A. As shown in FIG. 3B, inside the case 2 are accommodated a capacitor portion 4 having a back electrode plate 5 and a diaphragm 6, a mesh member 7, a microphone substrate 8, a conductive member 9, and the like. An insulating film 3 is provided on the inner surface of the case 2 to insulate the case 2 from components such as the capacitor portion 4 accommodated therein.

  The capacitor unit 4 includes a back electrode plate 5 disposed on the upper surface plate 2A side of the case 2, a vibration film 6 disposed on the opening window 2b side facing the back electrode plate 5, and the back electrode plate 5 and the vibration. A spacer 12 or the like interposed between the film 6 and the like is provided.

  The back electrode plate 5 of the capacitor unit 4 is made of, for example, a plastic thin plate plated with metal, and is formed in a circular shape having a size corresponding to the inside of the case 2. The back electrode plate 5 is provided with a plurality of sound passage holes 5 a facing the case side sound passage holes 2 a of the case 2. The sound wave that has entered from the case-side sound passage hole 2a passes through the sound passage hole 5a. Further, an electret layer that does not appear in the figure made of a polymer film such as fluorinated ethylene propylene is provided on the surface of the back electrode plate 5 on the vibrating membrane 6 side.

  The vibration film 6 of the capacitor unit 4 is made of a synthetic resin film or a metal thin film to which a metal is attached by vapor deposition or the like, and the size of the plane is set to be substantially equal to that of the back electrode plate 5. The vibration film 6 is vibrated by the sound wave that has passed through the sound passage hole 5 a of the back electrode plate 5, whereby the distance between the vibration film 6 and the back electrode plate 5 changes. Then, as the distance between the vibrating membrane 6 and the back electrode plate 5 changes, the capacitance of the capacitor unit 4 changes according to the frequency, amplitude, etc. of the sound wave.

  The mesh member 7 is interposed between the upper surface plate 2 </ b> A of the case 2 and the back electrode plate 5 of the capacitor unit 4. The mesh member 7 is set to a size that covers all the plurality of sound passage holes 5 a of the back electrode plate 5. By interposing the mesh member 7 between the upper surface plate 2A of the case 2 and the back electrode plate 5, dust, dust, and the like are prevented from entering the vibrating membrane 6 from the sound passage hole 5a of the back electrode plate 5. Therefore, the performance deterioration of the capacitor unit 4 can be prevented.

  The conductive member 9 electrically connects the diaphragm 6 of the capacitor unit 4 and the microphone substrate 8. The conductive member 9 is made of a conductor such as a copper alloy, and is formed in a ring shape having a size substantially equal to the outer shape of the back electrode plate 5 and the diaphragm 6. The capacitor unit 4 is placed on the microphone substrate 8 via the conductive member 9.

  The microphone substrate 8 is made of a disc having a size corresponding to the inside of the case 2. A through hole 15 is provided in the center of the circuit board. The through-hole 15 allows communication between the space between the microphone substrate 8 and the capacitor portion 4 and the space opposite to the capacitor portion 4 of the microphone substrate 8 formed by the electrostatic shield member 25 described later. A conductive member 9 is disposed on the upper surface 8a which is the surface of the microphone substrate 8 on the capacitor unit 4 side. Further, the lower surface 8 b, which is the surface opposite to the capacitor portion 4 of the microphone substrate 8, is exposed from the opening window 2 b of the case 2.

  FIG. 4 is an exploded perspective view showing a state in which the electrostatic shield member 25 is removed from the condenser microphone 1. As shown in FIG. 4, a signal side electrode 17, a ground side electrode 18, and an electrostatic shield electrode 19 are provided on the lower surface 8 b of the microphone substrate 8. The signal side electrode 17 and the ground side electrode 18 have an arc shape with the same radius of curvature, and are formed concentrically with the center of the microphone substrate 8. The electrostatic shield electrode 19 is formed concentrically with the center of the microphone substrate 8 and has a ring shape, and is disposed inside the signal side electrode 17 and the ground side electrode 18. The electrostatic shield electrode 19 is electrically connected to the ground side electrode 18 via an electrode (not shown).

  On the lower surface 8 b of the microphone substrate 8, a field effect transistor 10 showing a specific example of the converter and an electronic component 21 such as a capacitor are mounted inside the electrostatic shield electrode 19. The field effect transistor 10 includes a gate terminal 10a, a drain terminal 10b, and a source terminal 10c. The gate terminal 10a is electrically connected to the capacitor unit 4 via the microphone substrate 8 and the conductive member 9. Yes. The drain terminal 10b of the field effect transistor 10 is electrically connected to the signal side electrode 17 of the microphone substrate 8 via an electrode (not shown), and the source terminal 10c is connected to the ground side electrode 18 via an electrode (not shown). Electrically connected.

  The field effect transistor 10 converts the change in the capacitance of the capacitor unit 4 supplied via the gate terminal 10a into an electric signal (impedance conversion), and outputs the electric signal from the drain terminal 10b. Then, the electrical signal output from the drain terminal 10 b is supplied to the device board 121 of the electronic device on which the capacitor microphone 1 is mounted via the signal side electrode 17.

  An electrostatic shield member 25 that covers the through hole 15 and the electronic component 21 such as the field effect transistor 10 and the capacitor is attached to the electrostatic shield electrode 19 of the microphone substrate 8 by soldering. Like the case 2, the electrostatic shield member 25 is made of a metal member such as brass, and has a bottomed cylindrical body closed on one side. In a state where the capacitor microphone 1 is mounted on the device substrate 121 of the electronic device, the electrostatic shield member 25 and the field effect transistor 10 covered by the electrostatic shield member 25 are provided with an opening 121a provided on the device substrate 121. Inserted into.

  According to the condenser microphone 1 having such a configuration, the field effect transistor 10 is mounted on the lower surface 8 b of the microphone substrate 8, and the field effect transistor 10 is covered with the electrostatic shield member 25. Therefore, the gap formed between the microphone substrate 8 and the capacitor unit 4 can be reduced. In addition, the influence of external noise on the field effect transistor 10 due to electrostatic induction or the like can be reduced, and deterioration of the signal-to-noise ratio (S / N) can be suppressed to realize a high-quality microphone.

  Then, in a state where the capacitor microphone 1 is mounted on the device substrate 121, the electrostatic shield member 25 and the field effect transistor 10 covered with the electrostatic shield member 25 are inserted into the opening 121 a of the device substrate 121. Thereby, the height which protrudes from the apparatus board | substrate 121 of the capacitor | condenser microphone 1 can be made low, and size reduction and thickness reduction of the apparatus provided with the capacitor | condenser microphone 1 are realizable.

  As described above, in the capacitor microphone 1, since the field effect transistor 10 is mounted on the lower surface 8 b of the microphone substrate 8, the gap between the microphone substrate 8 and the capacitor unit 4 can be reduced. As a result, the space volume around the vibrating membrane 6 facing the microphone substrate 8 is reduced.

  The space volume around the vibrating membrane 6 is one of the factors that limit the sensitivity of the microphone. This is because when the space volume around the diaphragm 6 is reduced, the stiffness in the space around the diaphragm 6 increases (stiffness due to back cavity). It is because it restricts. Therefore, if the gap between the upper surface 8a of the microphone substrate 8 and the vibrating membrane 6 of the capacitor unit 4 is reduced, the spatial volume around the vibrating membrane 6 is reduced, and there is a concern that the sensitivity of the microphone is lowered.

  Therefore, in the condenser microphone 1, the through-hole 15 is provided in the microphone substrate 8, and the space formed by the microphone substrate 8 and the capacitor unit 4 communicates with the space formed by the microphone substrate 8 and the electrostatic shield member 25. I let you. Thereby, the space volume around the vibration film 6 can be increased, and an environment in which the vibration film 6 easily vibrates can be obtained. As a result, the gap between the microphone substrate 8 and the capacitor unit 4 can be reduced without reducing the sensitivity of the microphone.

  In the present embodiment, the electrostatic shield member 25 and the field effect transistor 10 are configured not to penetrate the opening 121a of the device substrate 121 (see FIG. 3B), but the electrostatic shield member 25 and the field effect transistor 10 are configured as follows. The opening 121a may be penetrated. The device substrate 121 is generally mounted with electronic components on both sides. Therefore, even if the field effect transistor 10 or the like passes through the opening 121a, the height of the portion protruding from the device substrate 121 is set so as not to exceed the height of the electronic component mounted on the device substrate 121. As a result, the combined thickness of the device substrate 121 and the condenser microphone 1 can be made thinner than before.

  5 and 6 show a modification of the condenser microphone 1 of the first embodiment. FIG. 5 is a perspective view seen from above, and FIG. 6 is a perspective view seen from below. The condenser microphone 31 shown in FIGS. 5 and 6 has the same configuration as the condenser microphone 1 of the first embodiment, and the only difference is the outer shape.

  The condenser microphone 31 has a case 32 that forms an exterior part. The case 32 is made of a metal member such as brass, and has a bottomed rectangular tube with one side closed. The upper surface plate 32A on the closed side of the case 32 is provided with a plurality of (11 in this embodiment) case-side sound passage holes 32a through which sound waves pass. The opening facing the upper plate 32A is an opening window 32b through which the microphone substrate 38 is exposed.

  Although not shown, like the condenser microphone 1, a capacitor portion, a mesh member, a conductive member, a microphone substrate 38 and the like are accommodated in the case 32. Each member accommodated in the case 32 is formed in a square having a size corresponding to the inside of the case 32.

  Similar to the microphone substrate 8 according to the first embodiment, a through hole (not shown) is provided in the microphone substrate 38. Further, two signal side electrodes 47, two ground side electrodes 48, and an electrostatic shield electrode (not shown) are provided on the lower surface 38b of the microphone substrate 38. An electrostatic shield member 45 that covers the through hole of the microphone substrate 38, a field effect transistor (not shown), and the like is attached to the electrostatic shield electrode by soldering.

  Also with the condenser microphone 31 having such a configuration, the same effect as that of the condenser microphone 1 of the first embodiment can be obtained. That is, in a state where the capacitor microphone 31 is mounted on the device substrate 121, the height of the capacitor microphone 31 protruding from the device substrate 121 can be reduced, and the device can be reduced in size and thickness. In addition, the influence of external noise on the field effect transistor due to electrostatic induction or the like can be reduced, and deterioration of the signal-to-noise ratio (S / N) can be suppressed to realize a high-quality microphone. In addition, since the through hole is provided in the microphone substrate 38, the space volume around the diaphragm can be increased, and the gap between the microphone substrate 38 and the capacitor portion can be reduced without reducing the sensitivity of the microphone. .

  Next, a second embodiment of the condenser microphone of the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view showing a second embodiment of the condenser microphone of the present invention.

  The condenser microphone 51 shown in FIG. 7 has the same configuration as the condenser microphone 1 of the first embodiment, and the only difference is that the electrostatic shield member 25 is attached to the device substrate 121. Therefore, the same components as those of the condenser microphone 1 according to the first embodiment are denoted by the same reference numerals as those of the condenser microphone 51, and redundant description is omitted.

  As shown in FIG. 7, the electrostatic shield member 25 of the condenser microphone 51 is attached to the electrostatic shield electrode 121b provided on the equipment substrate 121 by soldering. The electrostatic shield member 25 attached to the device substrate 121 covers the opening 121 a provided in the device substrate 121.

  The device substrate 121 has a through-hole electrode 121c for electrically connecting the ground side electrode 18 of the capacitor microphone 51 and the electrostatic shield electrode 121b in a state where the capacitor microphone 51 is mounted on the device substrate 121. Is provided. Thereby, the electrostatic shield member 25 is electrically connected to the ground-side electrode 18 of the condenser microphone 51.

  In a state where the capacitor microphone 51 is mounted on the device substrate 121, the field effect transistor 10 mounted on the lower surface 8 b of the microphone substrate 8 is inserted into the opening 121 a of the device substrate 121. The through hole 15 of the microphone substrate 8 is opposed to the opening 121 a of the device substrate 121.

  According to the condenser microphone 51 having such a configuration, the field effect transistor 10 is mounted on the lower surface 8 b of the microphone substrate 8. Therefore, the gap formed between the microphone substrate 8 and the capacitor unit 4 can be reduced. Then, in a state where the capacitor microphone 51 is mounted on the device substrate 121, the field effect transistor 10 is inserted into the opening 121 a of the device substrate 121. Thereby, the height which protrudes from the board | substrate 121 for apparatuses of the capacitor | condenser microphone 51 can be made low, and size reduction and thickness reduction of the apparatus provided with the capacitor | condenser microphone 51 are realizable.

  Further, according to the condenser microphone 51, the opening 121 a of the device substrate 121 into which the field effect transistor 10 is inserted is covered with the electrostatic shield member 25. Therefore, the influence of external noise on the field-effect transistor 10 due to electrostatic induction or the like can be reduced, and a high-quality microphone can be realized while suppressing deterioration of the signal-to-noise ratio (S / N).

  In the first and second embodiments described above, the case 2 and the electrostatic shield member 25 are formed of a metal member such as brass. However, as the material of the case 2 and the electrostatic shield member 25 according to the present invention, However, the present invention is not limited to this. The case 2 and the electrostatic shield member 25 according to the present invention can be formed of, for example, a synthetic resin containing metal powder.

  FIG. 8 shows a mobile phone terminal as an example of an electronic apparatus provided with the condenser microphone 1 having the configuration and operation as described above. The mobile phone terminal 101 is a so-called foldable mobile phone terminal configured such that two housings can be folded via a connecting portion. As shown in FIG. 8, the mobile phone terminal 101 rotates the first housing 102 and the second housing 103, which show a specific example of the device housing, and the first housing 102 and the second housing 103. The hinge part 104 grade | etc., Connected so that it is possible is provided.

  The first housing 102 is formed in a flat rectangular parallelepiped shape. A liquid crystal display 111 showing a specific example of a display screen, a speaker hole 112, and a camera unit 113 are provided on an inner surface 102a that is a surface of the first housing 102 that is overlapped with the second housing 103. Yes. The liquid crystal display 111 is formed in a large size so as to occupy the inner surface 102a. The speaker hole 112 and the camera portion 113 are disposed at the end opposite to the hinge portion 104.

  Similar to the first housing 102, the second housing 103 is formed in a flat rectangular parallelepiped shape. A plurality of operation keys 115, four function switching keys 116, a jog shuttle operation unit 117, and a sound collecting hole are provided on an inner surface 103 a that is a surface of the second housing 103 that is overlapped with the first housing 102. A microphone hole 119 or the like showing a specific example is provided. The plurality of operation keys 115 are disposed at a substantially central portion of the inner surface 103a. The four function switching keys 116 and the jog shuttle operation part 117 are arranged at the end part on the hinge part 104 side, and the microphone hole 119 is arranged at the end part opposite to the hinge part 104.

  Examples of the plurality of operation keys 115 include a dial key, a call key, and an end key corresponding to numbers and symbols of 1, 2, 3,. Examples of the four function switching keys 116 include a mail key for switching the function of the mobile phone terminal 101 to a mail function, a camera key for switching to a camera function, and the like. The jog shuttle operation unit 117 functions as a selection button for selecting a menu displayed on the liquid crystal display 111 and a shutter button when the function of the mobile phone terminal 101 is changed to a camera function.

  A device substrate 121 is provided inside the second housing 103. Various electronic components are mounted on the device substrate 121. An opening 121a (see FIG. 3B) is provided at a position corresponding to the microphone hole 119 of the device substrate 121, and the condenser microphone 1 is mounted so as to cover the opening 121a. The electrostatic shield member 25 of the capacitor microphone 1 and the field effect transistor 10 covered with the electrostatic shield member 25 are inserted into the opening 121a of the device substrate 121 (see FIG. 3B). The condenser microphone 1 converts the sound wave that has passed through the microphone hole 119 into an electrical signal.

  By applying the condenser microphone 1 (31, 51) of the present invention to the mobile phone terminal 101 having such a configuration, the combined thickness of the condenser microphone 1 and the device substrate 121 can be reduced. As a result, the thickness of the second housing 103 can be reduced, which can contribute to reducing the thickness of the entire mobile phone terminal 101.

  As described above, according to the condenser microphone and the electronic apparatus of the present invention, the converter is mounted on the surface of the microphone substrate opposite to the capacitor portion side, and the converter is covered with the electrostatic shield member. Then, in a state where the condenser microphone is mounted on the device substrate, the converter and the electrostatic shield member are inserted into the opening of the device substrate. Therefore, the height of the portion of the condenser microphone protruding from the device substrate can be reduced, and the combined thickness of the capacitor microphone and the device substrate can be reduced. As a result, it is possible to reduce the size and thickness of the device including the condenser microphone.

  In addition, a through hole was provided in the microphone substrate so that the space formed by the microphone substrate and the capacitor portion communicated with the space formed by the microphone substrate and the electrostatic shield member. Thereby, the space volume around the vibration film can be increased, and an environment in which the vibration film easily vibrates can be obtained. As a result, the gap between the microphone substrate and the capacitor unit can be reduced without reducing the sensitivity of the microphone.

  The present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, a mobile phone terminal has been described as an example of the electronic device. However, the present invention can also be applied to other electronic devices such as a video camera, a digital still camera, and a portable audio recorder.

It is the perspective view which looked at the 1st embodiment of the condenser microphone of the present invention from the upper part. It is the perspective view which looked at the 1st embodiment of the condenser microphone of the present invention from the lower part. 3A is a plan view of the first embodiment of the condenser microphone of the present invention, and FIG. 3B is a cross-sectional view taken along the line XX shown in FIG. 3A. It is a disassembled perspective view which shows the state which removed the electrostatic shielding member from 1st Embodiment of the condenser microphone of this invention. It is the perspective view which looked at the modification of 1st Embodiment of the condenser microphone of this invention from the upper direction. It is the perspective view which looked at the modification of 1st Embodiment of the condenser microphone of this invention from the downward direction. It is sectional drawing which shows 2nd Embodiment of the condenser microphone of this invention. It is explanatory drawing of the mobile telephone terminal which shows an example of the electronic device provided with the capacitor | condenser microphone of this invention. It is sectional drawing explaining the conventional condenser microphone.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 31, 51 ... Condenser microphone, 2, 32 ... Case, 2a ... Case side sound passage hole, 3 ... Insulating film, 4 ... Condenser part, 5 ... Back electrode plate, 5a ... Sound passage hole, 6 ... Vibration membrane, DESCRIPTION OF SYMBOLS 7 ... Mesh member 8, 38 ... Microphone board | substrate, 9 ... Conductive member, 10 ... Field effect transistor (converter), 10a ... Gate terminal, 10b ... Drain terminal, 10c ... Source terminal, 15 ... Through-hole, 17, 47 ... Signal side electrode 18, 48 ... Ground side electrode, 19 ... Electrostatic shield electrode, 25 ... Electrostatic shield member, 101 ... Mobile phone terminal (electronic device), 102 ... First housing, 103 ... Second Enclosure (equipment enclosure), 119 ... Microphone hole (sound collecting hole), 121 ... Equipment substrate, 121a ... Opening

Claims (5)

In condenser microphones mounted on equipment boards provided in electronic equipment,
A capacitor unit having a vibration film that vibrates by sound waves and a back electrode plate disposed to face the vibration film;
A microphone substrate having a through hole facing the capacitor portion;
A transducer that is mounted on a surface opposite to the surface facing the capacitor portion of the microphone substrate, and that converts impedance of the capacitance of the capacitor portion,
An electrostatic shield member attached to the microphone substrate and covering the converter and the through hole, and
The converter microphone and the electrostatic shield member are inserted into an opening provided in the device board. The back electrode plate has a sound passage hole through which the sound wave passes,
The condenser microphone according to claim 1, wherein the vibration film is disposed between the back electrode plate and the circuit board. A case for accommodating the capacitor unit and the microphone substrate;
The case has an opening window that exposes a surface of the microphone substrate on which the converter is mounted, and a case-side sound passage hole facing the sound passage hole of the back electrode plate. Item 3. A condenser microphone according to Item 2. In condenser microphones mounted on equipment boards provided in electronic equipment,
A capacitor unit having a vibration film that vibrates by sound waves and a back electrode plate disposed to face the vibration film;
A microphone substrate having a through hole facing the capacitor portion;
A transducer that is mounted on a surface opposite to the surface facing the capacitor portion of the microphone substrate, and that converts impedance of the capacitance of the capacitor portion,
An electrostatic shield member that closes an opening provided in the device substrate;
The condenser microphone is inserted into the opening of the device substrate, and the through hole is opposed to the opening. A device housing having a sound collecting hole through which sound waves pass;
A device substrate disposed inside the device housing and having an opening;
A condenser microphone mounted on the device substrate and opposed to the sound collecting hole of the device housing;
The condenser microphone is:
A capacitor unit having a vibration film that vibrates by sound waves and a back electrode plate disposed to face the vibration film;
A microphone substrate having a through hole facing the capacitor portion;
A transducer that is mounted on a surface opposite to the surface facing the capacitor portion of the microphone substrate, and that converts impedance of the capacitance of the capacitor portion,
An electrostatic shield member attached to the microphone substrate and covering the converter and the through hole, and
The electronic device, wherein the converter and the electrostatic shield member are inserted into the opening of the device substrate.

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