JP2010258720A - Acoustic transducer unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acoustic transducer unit which is capable of shielding electromagnetic waves flying from all directions with a simple configuration and can be manufactured inexpensively. <P>SOLUTION: The acoustic transducer unit includes: (a) a first member 30 having an opening 39 and a cavity portion 38 communicated with the opening 39; (b) a second member 20 which is bonded to the first member 30 and closes the opening 39 of the first member 30; and (c) acoustic transducer 2 which has an acoustic transducer portion 4 for transducing sound into an electric signal or transducing an electric signal into sound and is disposed within an internal space 40 formed of the cavity portion 38 of the first member 30 and the second member 20. An acoustic path 36 communicating with the internal space and an external space is formed in at least either of the first member 30 and the second member 20. The first member 30 and the second member 20 are made of high dielectric constant material. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an acoustic transducer unit, and more particularly to an acoustic transducer unit in which an acoustic conversion element such as a microphone or a speaker is housed in a housing.

  Conventionally, various configurations for preventing electromagnetic interference signals (noise) have been proposed for acoustic transducer units.

  For example, in the microphone package 101 shown in the cross-sectional view of FIG. 10, the microphone chip 105 and the LSI chip 107 are mounted on the bottom surface 113 a of the recess 113 formed in the ceramic multilayer substrate 103, and the ceramic multilayer substrate 103 is covered so as to cover the recess 113. A lid member 131 is joined to the upper surface 103a. The lid member 131 is made of a conductive material, and can block electromagnetic noise transmitted through the lid member 131 (see, for example, Patent Document 1).

JP 2008-66983 A

  In the configuration of FIG. 10, it is not disclosed that the ceramic multilayer substrate 103 itself has an electromagnetic wave shielding function. Therefore, it is easily affected by electromagnetic waves that fly from the side surface and the bottom surface and pass through the ceramic multilayer substrate 103.

  To cope with this, for example, a conductive layer may be formed on the ceramic multilayer substrate 103 to surround the periphery with a conductive material and perform electromagnetic shielding. However, for this purpose, the configuration must be complicated, making it difficult to manufacture and increasing the manufacturing cost. In addition, the degree of freedom in design is limited by the configuration for the electromagnetic shield.

  In view of such a situation, the present invention aims to provide an acoustic transducer unit that can block electromagnetic waves flying from all directions with a simple configuration and can be manufactured at low cost.

  In order to solve the above-described problems, the present invention provides an acoustic transducer unit configured as follows.

  The acoustic transducer unit includes: (a) a first member having an opening and a cavity communicating with the opening; and (b) a second member joined to the first member and closing the opening of the first member. And (c) an acoustic conversion element that converts sound into an electric signal or an electric signal into sound, and is disposed in an internal space formed by the hollow portion and the second member of the first member. An acoustic conversion element. An acoustic path that connects the internal space and the external space is formed in at least one of the first member and the second member. The first member and the second member are made of a high dielectric constant material.

  In the above configuration, the acoustic conversion element portion of the acoustic conversion element is surrounded by a high dielectric constant material. Since electromagnetic waves from the outside are attenuated mainly by reflection when passing through a high dielectric constant material, electromagnetic waves flying from all directions can be blocked. Since the first member and the second member themselves may be formed of a high dielectric constant material, a simple configuration can be achieved.

  In order to solve the above-mentioned problems, the present invention provides an acoustic transducer unit configured as follows.

  The acoustic transducer unit includes: (a) a first member having an opening and a cavity communicating with the opening; and (b) a second member joined to the first member and closing the opening of the first member. And (c) an acoustic conversion element that converts sound into an electric signal or an electric signal into sound, and is disposed in an internal space formed by the hollow portion and the second member of the first member. An acoustic conversion element. An acoustic path that connects the internal space and the external space is formed in at least one of the first member and the second member. The first member is made of a conductive material, and the second member is made of a high dielectric constant material.

  In the above configuration, the acoustic conversion element portion of the acoustic conversion element is surrounded by a high dielectric constant material or a conductive material. Since electromagnetic waves from the outside are attenuated mainly by reflection when passing through a high dielectric constant material or conductive material, electromagnetic waves flying from all directions can be blocked. Since the first member itself may be formed of a conductive material and the second member itself may be formed of a high dielectric constant material, a simple configuration can be achieved.

  In order to solve the above-mentioned problems, the present invention provides an acoustic transducer unit configured as follows.

  The acoustic transducer unit includes: (a) a first member having an opening and a cavity communicating with the opening; and (b) a second member joined to the first member and closing the opening of the first member. And (c) an acoustic conversion element that converts sound into an electric signal or an electric signal into sound, and is disposed in an internal space formed by the hollow portion and the second member of the first member. An acoustic conversion element. An acoustic path that connects the internal space and the external space is formed in at least one of the first member and the second member. The first member is made of a high dielectric constant material, and the second member is made of a conductive material.

  In the above configuration, the acoustic conversion element portion of the acoustic conversion element is surrounded by a high dielectric constant material or a conductive material. Since electromagnetic waves from the outside are attenuated mainly by reflection when passing through a high dielectric constant material or conductive material, electromagnetic waves flying from all directions can be blocked. Since the first member itself may be formed of a high dielectric constant material and the second member itself may be formed of a conductive material, a simple configuration can be achieved.

  In order to solve the above-mentioned problems, the present invention provides an acoustic transducer unit configured as follows.

  The acoustic transducer unit includes: (a) an intermediate member having openings at both ends and formed with hollow holes communicating between the openings; and (b) a first member that is joined to both ends of the intermediate member and closes the openings. 1 and 2 end members, and (c) an acoustic transducer element for converting sound into an electric signal or converting an electric signal into sound, and the hollow hole of the hollow member and the first and second ends And an acoustic conversion element disposed in an internal space formed by the member. At least one of the intermediate member, the first end member, and the second end member is formed with an acoustic path that communicates the internal space and the external space. One of the intermediate member and the first and second end members is made of a high dielectric constant material, and the other is made of a conductive material.

  In the above configuration, the acoustic conversion element portion of the acoustic conversion element is surrounded by a high dielectric constant material or a conductive material. Since electromagnetic waves from the outside are attenuated mainly by reflection when passing through a high dielectric constant material or conductive material, electromagnetic waves flying from all directions can be blocked. Since the intermediate member and the end member itself may be formed of a conductive material or a high dielectric constant material, a simple configuration can be achieved.

  Preferably, in each of the above configurations, the high dielectric constant material has a relative dielectric constant of 10 or more.

  In this case, an electromagnetic shielding effect of 10 dB or more can be expected with a high dielectric constant material.

  More preferably, the high dielectric constant material has a relative dielectric constant of 30 or more.

  In this case, an electromagnetic shielding effect of 20 dB or more can be expected with a high dielectric constant material.

  The acoustic transducer unit of the present invention can block electromagnetic waves flying from all directions with a simple configuration and can be manufactured at low cost.

2A is an exploded perspective view of an acoustic transducer unit, and FIG. (Example 1) It is sectional drawing of an acoustic transducer unit. (Example 1) It is sectional drawing of an acoustic transducer unit. (Example 2) It is sectional drawing of an acoustic transducer unit. (Example 3) It is sectional drawing of an acoustic transducer unit. Example 4 It is sectional drawing of an acoustic transducer unit. (Example 5) It is sectional drawing of an acoustic transducer unit. (Example 6) It is sectional drawing of an acoustic transducer unit. (Example 7) It is a graph which shows the relationship between a dielectric constant and attenuation amount. It is sectional drawing of an acoustic transducer unit. (Conventional example)

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  Example 1 An acoustic transducer unit 10 of Example 1 will be described with reference to FIGS. 1, 2, and 9.

  1A is an exploded perspective view of the acoustic transducer unit 10, and FIG. 1B is an assembled perspective view thereof. FIG. 2 is a cross-sectional view showing the configuration of the acoustic transducer unit 10. As shown in FIGS. 1 and 2, the acoustic transducer unit 10 has a microphone element 2 that is an acoustic conversion element housed in a housing constituted by a first member 30 and a second member 20. .

  The first member 30 is a member in which a cylindrical portion 32 and a bottom portion 34 are coupled, and a concave portion 38 is formed by the cylindrical portion 32 and the bottom portion 34. The recess 38 is a cavity that communicates with the opening 39 formed in the upper surface 31 of the first member 30. The first member 30 is made of a high dielectric constant material. For example, the first member 30 is formed integrally with the terminal member 50 by an insert molding method using a composite material in which a high dielectric constant ceramic powder or the like is dispersed in a resin material. .

  The terminal member 50 includes an internal terminal portion 52 that extends into the recess 38 of the first member 30, an external terminal portion 56 that extends to an external space outside the housing, and the internal terminal portion 52 and the external terminal portion 56. The intermediate portion 54 is embedded in the bottom 34 of the first member 30. The terminal member 50 is formed of a conductive material such as metal, for example, copper.

  The microphone element 2 is mounted on the bottom 34 of the first member 30, the upper surface 2 a faces the second member 20, and the internal terminal portion 52 of the terminal member 50 is connected to the connection terminal 6 formed on the lower surface 2 b of the microphone element 2. Connection is made by conductive adhesive, soldering, ultrasonic bonding, or the like. For example, the connection is made using Au bumps, solder bumps, conductive paste, nano paste, or the like.

  The second member 20 is a plate-like member made of a high dielectric constant material, and is formed using, for example, a composite material in which a powder such as a high dielectric constant ceramic is dispersed in a resin material. The second member 20 is joined to the upper surface 31 of the first member 30 by an adhesive, thermocompression bonding, thermal fusion, or the like so as to close the opening 39 formed in the upper surface 31 of the first member 30. Accordingly, the microphone element 2 is sealed in the internal space 40 formed by the concave portion 34 of the first member 30 and the second member 20.

  A through hole 36 is formed in the bottom 34 of the first member 30 as an acoustic path that connects the internal space 40 in which the microphone element 2 is disposed and the external space.

  The acoustic path that communicates the internal space 40 where the microphone element 2 is disposed and the external space may be formed in the second member 20 or in both the first member 30 and the second member 20. . Further, even if the inner space 40 is formed so as to reach the outer space via the first member 30 and the second member 20, the inner space 40 is formed so as to reach the outer space via the second member 30 and the first member 20. May be. Moreover, even if it forms two or more, you may form so that it may merge or branch.

  The external terminal portion 56 of the terminal member 50 is electrically connected to an external circuit (not shown) when the acoustic transducer unit 10 is mounted on an external circuit (not shown).

  The microphone element 2 is a module component including an acoustic conversion element unit (sensor unit) 4 that converts sound into an electric signal and a peripheral circuit, and is, for example, a MEMS microphone. Instead of the microphone element 2, an acoustic conversion element that converts an electrical signal into sound, such as a speaker element, may be used.

  The microphone element 2 is disposed in an internal space 40 formed by the concave portion 38 of the first member 30 and the second member 20, and the periphery of the microphone element 2 is surrounded by the first member 30 and the second member 20. Yes. Since electromagnetic waves from the outside are attenuated mainly by reflection when passing through the first member 30 or the second member 20 made of a high dielectric constant material, electromagnetic waves flying to the microphone element 2 from any direction are blocked, and the microphone element 2 is electromagnetically shielded.

ここで、ε_ｒ１、μ_ｒ１は媒質１中の比誘電率と比透磁率であり、ε_ｒ２、μ_ｒ２は媒質２中の比誘電率と比透磁率である。 Namely, the incident electric field amplitudes E _i in the medium 1 in the medium 2, the transmission wave amplitude E _t, when divided into the reflected wave amplitude E _r, permeability coefficient t and the reflection coefficient r, as follows expressed.

Here, ε _r1 and μ _r1 are a relative permittivity and a relative permeability in the medium 1, and ε _r2 and μ _r2 are a relative permittivity and a relative permeability in the medium 2.

である。 At this time, the reflectance R and the transmittance T are

It is.

When the ratio of the relative dielectric constant ε _{r2 in} the medium 2 to the relative dielectric constant ε _r1 in the medium 1 is A, the ratio of the dielectric constant in the medium 1 and the medium 2 is A = ε _r2 / ε _r1 .
From these equations, the value of r is calculated from the value of A. Here, in particular, when the medium 1 is air, the relative dielectric constant ε _r2 in the medium 2 is set as the relative dielectric constant ε _r and the change in attenuation with respect to the change in ε _r is calculated, as shown in the graph of FIG. Become. Here, since the transmittance of the electromagnetic wave incident on the medium 2 from the medium 1 is T, the attenuation is defined in dB by 10 logT.

When the acoustic transducer unit is present in the air, it can be seen from FIG. 9 that, for example, if the relative permittivity ε _r is 10 or more, an attenuation effect of 10 dB or more is obtained, and if the relative permittivity ε _r is 30 or more, 20 dB It turns out that the above attenuation effect is acquired. Based on the relative dielectric constant epsilon _r and the attenuation of the relationship shown in FIG. 9, select the specific dielectric constant epsilon _r in accordance with the electromagnetic shielding effect of expected first member 30 by using a material relative dielectric constant epsilon _r And by forming the 2nd member 20, in the acoustic transducer unit 10, a desired electromagnetic shielding effect, especially a favorable electromagnetic shielding effect can be obtained in the frequency range of 100 Hz to 10 GHz.

For example, when the relative permittivity of the high dielectric constant material forming the first member 30 and the second member 10 is 10 or more, an electromagnetic shielding effect of 10 dB or more can be expected, which is preferable. It is more preferable that the high dielectric constant material forming the first member 30 and the second member 10 has a relative dielectric constant of 30 or more because an electromagnetic shielding effect of 20 dB or more can be expected. When the medium 1 is a medium other than air, for example, a resin or adhesive having a relative dielectric constant ε _r1a , the attenuation can be calculated in the same manner as described above by replacing the relative dielectric constant ε _r1 with ε _r1a . Further, assuming that the dielectric constant ε ₀ in vacuum is ε ₀ = 8.85 × 10 ⁻¹² [F / m], for example, when the medium 1 is dry air, the dielectric constant of air is the dielectric constant ε in vacuum. Assuming that it can be approximated to ₀ , when the relative dielectric constant ε _r in the medium 2 is 10, the dielectric constant ε ₂ in the medium ₂ is ε ₂ = 8.85 × 10 ⁻¹¹ [F / m].

  The first member 30 and the second member 20 that surround the entire periphery of the microphone element 2 have a simple configuration, and can be easily and inexpensively manufactured by an insert molding method using a high dielectric constant material. It is easy to assemble.

  In addition, the acoustic transducer unit 10 does not need to form a conductive layer or the like for electromagnetic shielding in the housing that houses the microphone element 2, that is, the first member 30 and the second member 20, so An acoustic optimum design can be performed without being restricted by the configuration for the shield.

  Example 2 An acoustic transducer unit 10a of Example 2 will be described with reference to FIG.

  The acoustic transducer unit 10a according to the second embodiment is configured in substantially the same manner as the acoustic transducer unit 10 according to the first embodiment. In the following, the same reference numerals are used for the same components as in the first embodiment, and differences from the first embodiment will be mainly described.

  FIG. 3 is a cross-sectional view of the acoustic transducer unit 10a according to the second embodiment. As shown in FIG. 3, in the acoustic transducer unit 10a of the second embodiment, a housing is constituted by the first member 30a and the second member 20a, as in the acoustic transducer unit 10 of the first embodiment. The microphone element 2 is housed in an internal space 40 formed by the recess 38 of the member 30a and the second member 20a.

  Unlike the first embodiment, in the acoustic transducer unit 10a of the second embodiment, the microphone element 2 is mounted on the plate-like second member 20a, and the microphone element 2 is covered by the first member 30a in which the recess 38 is formed. ing.

  The first member 30a is a member in which the cylindrical portion 33 and the top portion 35 are coupled, and the concave portion 38 that communicates with the opening 39a formed in the lower surface 31a of the first member 30a by the cylindrical portion 33 and the top portion 35. Is formed. The first member 30a is made of a conductive material such as metal or conductive resin, and is formed by, for example, injection molding, pressing, cutting, or the like.

  The second member 30a is made of a high dielectric constant material as in the first embodiment. However, unlike the first embodiment, the second member 30a is formed integrally with the terminal member 50 by an insert molding method. The second member 20a is joined to the lower surface 31a of the first member 30a by an adhesive, thermocompression bonding, thermal fusion or the like so as to cover the opening 39a formed in the lower surface 31a of the first member 30a.

  In the terminal member 50, as in the first embodiment, the internal terminal portion 52 and the external terminal portion 56 are connected by the intermediate portion 54. A connection terminal 6 formed on the lower surface 2 b of the microphone element 2 is connected to the internal terminal portion 52. A through hole 24 is formed in the second member 20a as an acoustic path that communicates between the internal space 40 and the external space.

  In the acoustic transducer unit 10a of the second embodiment, the microphone element 2 is surrounded by the second member 20a made of a high dielectric constant material and the first member 30a made of a conductive material. Since the electromagnetic wave from the outside is attenuated mainly by reflection when passing through the second member 20a made of a high dielectric constant material or the first member 30a made of a conductive material, the acoustic transducer unit 10a of the second embodiment Electromagnetic waves flying from the direction can be blocked.

  Further, the first member 30a and the second member 20a constituting the housing have a simple configuration and can be easily and inexpensively manufactured by an insert molding method or the like.

  Further, the acoustic transducer unit 10a does not need to form a conductive layer or the like for electromagnetic shielding on the first member 30a and the second member 20a. Design can be done.

  Example 3 An acoustic transducer unit 10b of Example 3 will be described with reference to FIG.

  FIG. 4 is a cross-sectional view illustrating a configuration of the acoustic transducer unit 10b according to the third embodiment. As shown in FIG. 4, the acoustic transducer unit 10b of the third embodiment is configured in substantially the same manner as the acoustic transducer unit 10 of the first embodiment.

  However, the acoustic transducer unit 10b of the third embodiment is different from the acoustic transducer unit 10 of the first embodiment in that the first member 20b is made of a conductive material instead of a high dielectric constant material.

  In the acoustic transducer unit 10b of the third embodiment, the periphery of the microphone element 2 is surrounded by the first member 30b made of a high dielectric constant material and the second member 20b made of a conductive material. Electromagnetic waves are blocked. Further, the first member 30b and the second member 20b constituting the housing have a simple configuration, and can be easily and inexpensively manufactured by an insert molding method or the like. Further, the acoustic transducer unit 10b does not need to form a conductive layer for electromagnetic shielding on the first member 30b and the second member 20b. Design can be done.

  Example 4 An acoustic transducer unit 10c of Example 4 will be described with reference to FIG.

  FIG. 5 is a cross-sectional view illustrating a configuration of an acoustic transducer unit 10c according to the fourth embodiment. As shown in FIG. 5, the acoustic transducer unit 10c of the fourth embodiment is configured in substantially the same manner as the acoustic transducer unit 10a of the second embodiment.

  However, the acoustic transducer unit 10c of the fourth embodiment is different from the acoustic transducer unit 10a of the second embodiment in that the second member 20c is made of a conductive material instead of a high dielectric constant material.

  In the acoustic transducer unit 10c according to the fourth embodiment, since the periphery of the microphone element 2 is surrounded by the first member 30c made of a high dielectric constant material and the second member 20c made of a conductive material, the acoustic transducer unit 10c flies from all directions. Electromagnetic waves are blocked. In addition, the first member 30c and the second member 20c constituting the housing have a simple configuration, and can be easily and inexpensively manufactured by an insert molding method or the like. The acoustic transducer unit 10c does not need to form a conductive layer for electromagnetic shielding on the first member 30c and the second member 20c. Design can be done.

  <Example 5> An acoustic transducer unit 10d of Example 5 will be described with reference to FIG.

  FIG. 6 is a cross-sectional view illustrating a configuration of an acoustic transducer unit 10d according to the fifth embodiment. As shown in FIG. 6, the acoustic transducer unit 10d of the fifth embodiment is configured in substantially the same manner as the acoustic transducer unit 10 of the first embodiment.

  However, the acoustic transducer unit 10d of the fifth embodiment is different from the acoustic transducer unit 10 of the first embodiment in that the first member 30d is made of a conductive material instead of a high dielectric constant material.

  In the acoustic transducer unit 10d of the fifth embodiment, the periphery of the microphone element 2 is surrounded by the second member 20d made of a high dielectric constant material and the first member 30d made of a conductive material. Electromagnetic waves are blocked. Further, the first member 30d and the second member 20d constituting the housing have a simple configuration, and can be easily and inexpensively manufactured by an insert molding method or the like. Further, the acoustic transducer unit 10d does not need to form a conductive layer for electromagnetic shielding on the first member 30d and the second member 20d. Design can be done.

  Example 6 An acoustic transducer unit 10e of Example 6 will be described with reference to FIG.

  FIG. 7 is a cross-sectional view illustrating a configuration of an acoustic transducer unit 10e according to the sixth embodiment. As shown in FIG. 7, the acoustic transducer unit 10e according to the sixth embodiment is configured in substantially the same manner as the acoustic transducer unit 10 according to the first embodiment, but differs from the acoustic transducer unit 10 according to the first embodiment. A cylindrical portion and a bottom portion of one member are formed separately.

  That is, the acoustic transducer unit 10b according to the sixth embodiment includes the intermediate member 30e and the first and second end members 20e and 22e.

  The intermediate member 30e is a cylindrical member made of a conductive material, having openings 39s and 39t at both ends, and having a hollow hole 37 communicating between the openings 39s and 39t. The intermediate member 30e corresponds to the cylindrical portion 32 of the first member 30 in the acoustic transducer unit of the first embodiment.

  The first and second end members 20e and 22e are made of a high dielectric constant material, and are joined to both end faces 31e and 33e of the intermediate member 30e made of a conductive material, respectively, and close the openings 39s and 39t of the intermediate member 30e. Of the first and second end members 20e and 22e, one 22e corresponds to the bottom 34 of the first member 30 in the acoustic transducer unit 10 of the first embodiment, and the other 20e corresponds to the acoustic transducer unit 10 of the first embodiment. This corresponds to the second member 20 in FIG. An internal space 40 is formed by the hollow hole 37 of the intermediate member 30 e and the first and second end members 20 e and 22 e, and the microphone element 2 is disposed in the internal space 40.

  The second end member 22e is formed integrally with the terminal member 50 by an insert molding method, and an intermediate portion 54 of the terminal member 50 is embedded. The connection terminal 6 formed on the lower surface 2b of the microphone element 2 is connected to the internal terminal portion 52 of the terminal member 50 exposed on the upper surface side of the second end member 22e. A through hole 25 is formed in the second end member 22e as an acoustic path that communicates between the internal space 40 and the external space.

  In the acoustic transducer unit 10e of Example 3, the periphery of the microphone element 2 is surrounded by the first and second end members 20e and 22e made of a high dielectric constant material and the intermediate member 30e made of a conductive material. , Electromagnetic waves coming from all directions are blocked. Further, the intermediate member 30e and the first and second end members 20e and 22e constituting the housing have a simple configuration and can be easily and inexpensively manufactured by an insert molding method or the like. In addition, since the acoustic transducer unit 10e does not need to form a conductive layer or the like for electromagnetic shielding on the intermediate member 30e and the first and second end members 20e and 22e, the acoustic transducer unit 10e is restricted by a conductive layer or the like. Therefore, the acoustic optimum design can be performed.

  Example 7 An acoustic transducer unit 10f of Example 7 will be described with reference to FIG.

  FIG. 8 is a cross-sectional view illustrating a configuration of an acoustic transducer unit 10f according to the seventh embodiment. As shown in FIG. 8, the acoustic transducer unit 10f of the seventh embodiment is configured in substantially the same manner as the acoustic transducer unit 10e of the sixth embodiment. The difference from the acoustic transducer unit 10e of the sixth embodiment is that the intermediate member 30f is made of a high dielectric constant material instead of a conductive material, and the first and second end members 20f and 22f are made of a conductive material instead of a high dielectric constant material. It is a point.

  In the acoustic transducer unit 10f of the seventh embodiment, the periphery of the microphone element 2 is surrounded by the intermediate member 30f made of a high dielectric constant material and the first and second end members 20f and 22f made of a conductive material. , Electromagnetic waves coming from all directions are blocked. Further, the intermediate member 30f and the first and second end members 20f and 22f constituting the housing have a simple configuration, and can be easily and inexpensively manufactured by an insert molding method or the like. The acoustic transducer unit 10f does not need to form a conductive layer or the like for electromagnetic shielding on the intermediate member 30f and the first and second end member first members 20f and 22f. An acoustic optimal design can be performed without any restrictions.

  <Summary> As described above, the acoustic transducer unit according to the present invention in which at least a part of the housing surrounding the acoustic transducer is formed using a high dielectric constant material can easily prevent electromagnetic waves flying from all directions. It can be cut off with a simple structure and can be manufactured at low cost. Further, the degree of freedom in designing the acoustic transducer unit is improved.

  The present invention is not limited to the above embodiment, and can be implemented with various modifications.

  For example, in the first to seventh embodiments, the microphone element 2 is mounted in the housing with a face-down structure, but may be mounted in the housing with a face-up structure by wire bonding or the like.

  Further, the terminal part 50 is extended from the external terminal part 56 side, bent from the bottom surface of the housing along the side surface and the top surface, and the terminal part for mounting the acoustic transducer unit on the external circuit is not the bottom surface of the housing. You may make it provide in the upper surface of a housing. In this case, the direction of the acoustic path at the time of mounting can be easily changed by simply changing the bending direction of the terminal member 50 in the same package. For example, one type of package can correspond to the upper hole and the lower hole.

  Further, the internal terminal portion 52 side of the terminal member 50 protrudes into the internal space 40, and the protruding portion has elasticity, and biases the microphone element 2 connected to the internal terminal portion 52 of the terminal member 50, so that the microphone element 2 may be configured to elastically contact the top surface 2 a of the internal space 40. In this case, at the same time when the first member 30 and the second member 20 are joined, the upper surface 2a of the microphone element 2 is brought into contact with the top surface 40x of the internal space 40, so that an inexpensive assembly is possible. Further, by completely sealing the microphone element 2 in the internal space 40, it is possible to eliminate deterioration of sensitivity characteristics due to sound leakage.

2 Microphone element (acoustic transducer)
2a Upper surface 2b Lower surface 4 Acoustic transducer element 6 Connection terminal 10, 10a to 10f Acoustic transducer unit 20, 20a to 20d Second member 20e, 20f First end member 22e, 22f Second end member 24, 25 Through hole (Acoustic path)
30, 30a to 30d First member 30e, 30f Intermediate member 31 Upper surface 31a Lower surface 31e End surface 32, 33 Tube portion 33e End surface 34 Bottom portion 35 Top portion 36 Through hole (acoustic path)
37 Hollow hole 38 Recess (cavity)
39, 30a, 39s, 39t Opening 40 Internal space 40x Top 50 Terminal member 52 Internal terminal part 54 Intermediate part 56 External terminal part

Claims (6)

A first member having an opening and a cavity communicating with the opening;
A second member joined to the first member and closing the opening of the first member;
An acoustic transducer having an acoustic transducer element for converting sound into an electrical signal or converting an electrical signal into acoustic and disposed in an internal space formed by the hollow portion and the second member of the first member When,
With
An acoustic path that connects the internal space and the external space is formed in at least one of the first member and the second member,
The acoustic transducer unit according to claim 1, wherein the first member and the second member are made of a high dielectric constant material. A first member having an opening and a cavity communicating with the opening;
A second member joined to the first member and closing the opening of the first member;
An acoustic transducer having an acoustic transducer element for converting sound into an electrical signal or converting an electrical signal into acoustic and disposed in an internal space formed by the hollow portion and the second member of the first member When,
With
An acoustic path that connects the internal space and the external space is formed in at least one of the first member and the second member,
The acoustic transducer unit according to claim 1, wherein the first member is made of a conductive material, and the second member is made of a high dielectric constant material. A first member having an opening and a cavity communicating with the opening;
A second member joined to the first member and closing the opening of the first member;
An acoustic transducer having an acoustic transducer element for converting sound into an electrical signal or converting an electrical signal into acoustic and disposed in an internal space formed by the hollow portion and the second member of the first member When,
With
An acoustic path that connects the internal space and the external space is formed in at least one of the first member and the second member,
The acoustic transducer unit according to claim 1, wherein the first member is made of a high dielectric constant material, and the second member is made of a conductive material. An intermediate member having openings at both ends and formed with a hollow hole communicating between the openings;
First and second end members respectively bonded to both ends of the intermediate member and closing the opening;
It has an acoustic transducer element for converting sound into an electric signal or electric signal into sound, and is disposed in an internal space formed by the hollow hole of the hollow member and the first and second end members. An acoustic transducer,
With
At least one of the intermediate member, the first end member, and the second end member is formed with an acoustic path that communicates the internal space and the external space;
One of the intermediate member and the first and second end members is made of a high dielectric constant material, and the other is made of a conductive material.   The acoustic transducer unit according to claim 1, wherein the high dielectric constant material has a relative dielectric constant of 10 or more.   The acoustic transducer unit according to claim 5, wherein a relative dielectric constant of the high dielectric constant material is 30 or more.

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