JP4865578B2 - Condenser microphone - Google Patents

Description

  The present invention relates to a condenser microphone in which a microphone unit side is soldered and integrally connected to a circuit board side on which necessary members including a filter and an output circuit are mounted, and the whole is housed in a protective case. Technology.

One of the condenser microphones is a gooseneck type microphone that is frequently used for conferences. As shown in FIG. 3 of Patent Document 1 below, the gooseneck type microphone is usually arranged in a state in which a protective case containing a microphone unit and a circuit board on which a filter and an output circuit are mounted are separated. And they are electrically connected to each other via a microphone cord.
JP 2005-323222 A

  In addition, since the condenser microphone usually has a part of the microphone cord in the shield case that houses the circuit board, when a strong electromagnetic wave is applied to the microphone cord such as when a mobile phone is used at a close distance, It is said that noise caused by the electromagnetic wave is generated.

For this reason, in a condenser microphone, as a technique for avoiding the generation of noise caused by electromagnetic waves entering through a microphone cord, for example, a necessary member including a filter and an output circuit as shown in Non-Patent Document 1 below There has already been proposed a condenser microphone in which the microphone unit side is soldered and integrally connected to the circuit board side on which is mounted, and the whole is housed in a protective case.
Audiotechnica product catalog (see “For Sound Contractor”, page 16)

  FIG. 3 is an explanatory diagram including an entire configuration example of a conventional condenser microphone including the above-described Non-Patent Document 1 and including a cross-sectional structure thereof. FIG. 4 is an enlarged view of the condenser microphone portion in FIG.

  As shown in these drawings, the condenser microphone 1 includes at least a protective case 2, a microphone unit 3 and a circuit board 6 that are integrally stored in the protective case 2 while ensuring a conductive connection. ing.

  In this case, the condenser microphone 1 is integrally connected with the flexible pipe 7 on the base end side of the protective case 2, and the whole is configured as a gooseneck type microphone.

  As is clear from FIG. 4, the condenser microphone 1 includes a unit case 4 made of bottomed cylindrical aluminum with the inner bottom surface 4a side positioned on the front end side, and an opening side of the unit case 4 by caulking and sealing. The built-in member 5 is composed of a plurality of components arranged at predetermined positions in the unit case 4 via the unit substrate 5b. In this case, the necessary continuity between the diaphragm ring 5a that constitutes the built-in member 5 and is accommodated on the inner bottom surface 4a side, and the unit substrate 5b is that the caulking portion 4b formed on the opening side of the unit case 4 is a unit. It is ensured by contacting a conductive pattern (not shown) provided on the peripheral side of the substrate 5b.

  On the other hand, the circuit board 6 on which necessary members including a filter and an output circuit are mounted is arranged in a positional relationship orthogonal to the surface direction of the unit board 5b, and is formed with a lateral width substantially equal to the inner diameter of the unit case 4. ing.

  Further, output terminals 5d of FETs (impedance converters) 5c projecting in pairs from a substantially central portion of the unit substrate 5b are soldered to the predetermined conductive pattern on the circuit board 6 side. In the illustrated example, only one output terminal 5d is shown, but the other output terminal 5d is similarly soldered to the back surface side. As a result, the circuit board 6 side secures necessary conduction with the microphone unit 3 side.

  On the other hand, the protective case 2 includes a case main body 2a for storing the circuit board 6 and a cap portion for storing the microphone unit 3 and having a sound collecting opening that is detachably covered on the distal end side of the case main body 2a. 2b and a base 2c that holds the flexible pipe 7 and is connected to the base end side of the case main body 2a.

  As described above, the condenser microphone 1 is formed by the microphone unit 3 and the circuit board 6 being integrated while ensuring necessary conduction between the microphone unit 3 and the circuit board 6 and housed in the protective case 2.

  By the way, in the illustrated example of the condenser microphone 1, the unit case 4 is electrically connected to a ground pattern (not shown) of the unit substrate 5 b via the caulking portion 4 b, and the unit substrate 5 b is electrically connected to a ground pattern (not shown) on the circuit board 6 side. The ground side conductive path is secured.

  As a result, the condenser microphone 1 can obtain a shielding effect against electromagnetic waves generated when a mobile phone is used at a close distance, and can avoid generation of hum noise caused by the penetration of electromagnetic waves. .

  However, in the illustrated example of the condenser microphone 1, the microphone unit 3 and the circuit board 6 are integrated and housed in the case main body 2 a having an inner diameter substantially equal to the width of the circuit board 6. The Rukoto. For this reason, the circuit board 6 is forcibly accommodated halfway with the edge side along the length direction being in sliding contact with the inner peripheral surface of the case main body 2a.

 For this reason, the circuit board 6 having a thin plate shape is pushed in without being swung in the direction orthogonal to the surface direction by being screwed in the microphone unit 2 side to some extent when the circuit board 6 is housed. As a result, the unit board 5b soldered to the circuit board 6 side receives the stress generated when the circuit board 6 side is swung at the soldering site S in a concentrated manner.

  In particular, since the unit substrate 5b is soldered to the circuit board 6 at the substantially central portion thereof, the lever action with the soldered portion S as a fulcrum acts and receives a pressing force in the direction in which the caulking portion 4b is loosened. become. As a result, the surface direction of the unit substrate 5b is inclined from the horizontal position, and the contact between the caulking portion 4b and the ground pattern on the unit substrate 5b (not shown) becomes uncertain.

  On the other hand, the loosening of the caulking force once generated does not return to the original even when the stress applied to the unit substrate 5b is released. For this reason, the microphone unit 3 and the circuit board 6 are housed in the protective case 2 in a state where only an insufficient ground-side conductive path is formed between them. As a result, the condenser microphone 1 tends to cause a problem of generating hum noise in a state where a sufficient ground cannot be obtained.

  Moreover, as shown in FIG. 3, when the flexible pipe 7 is connected to the base end side of the protective case 2, the flexible pipe 7 side bends as the condenser microphone 1 side moves, so that the same as described above. There has also been a problem that the hum noise similar to the above is generated in the condenser microphone 1 due to the loosening of the caulking force.

  In view of the above-described problems of the prior art, the present invention provides a stable ground-side conductivity between the microphone unit side and the circuit board side even when the caulking force of the caulking portion of the unit case is stored in the protective case in a relaxed state. An object of the present invention is to provide a condenser microphone that secures a path and can avoid generation of hum noise.

  The present invention has been made to achieve the above object, and includes a unit case having a bottomed cylindrical shape and a plurality of unit substrates that are caulked and sealed through caulking portions formed on the opening surface side of the unit case. At least a microphone unit comprising a built-in member, and a circuit board on which necessary members including a filter and an output circuit are mounted and arranged in a positional relationship orthogonal to the surface direction of the unit board, the microphone unit and the A circuit board is a condenser microphone in which a ground-side conductive path is secured by being soldered to each other via the unit board, and the unit case can be soldered. The circuit board is formed with a lateral width substantially equal to the outer diameter of the caulking portion of the unit case. The unit case and the circuit board are firmly formed through soldering between the caulking portion and the ground pattern. The main feature is that it is conductively connected.

  In this case, it is desirable that a flexible pipe is integrally connected to the base end side of the protective case.

  According to the first aspect of the present invention, in the condenser microphone, the unit case of the microphone unit is formed of a metal material that can be soldered, and the ground pattern is formed on the circuit board at a position facing the caulking portion when stored in the protective case. Since it is provided, the caulking portion on the unit case side and the ground pattern on the circuit board side can be soldered to stably secure the ground-side conductive path. As a result, the condenser microphone has a ground-side conductive path formed by directly conducting and connecting the caulking portion and the ground pattern on the circuit board side even if the caulking force of the caulking portion is loosened. The generation of hum noise can be avoided.

  In addition, according to the second aspect of the present invention, the entire condenser microphone is a gooseneck microphone in which a flexible pipe is connected to the base end side of the protective case and the flexible pipe is repeatedly bent to move the condenser microphone. Even if comprised, since a ground side conductive path can be ensured, it can be used for a long-term and stably suitable use.

  FIG. 1 is an explanatory view showing a cross-sectional structure of an example of the present invention, and FIG. 2 is an enlarged view showing a main part of the example shown in FIG. According to these figures, the condenser microphone 11 includes a plurality of unit cases 43 including a bottomed cylindrical unit case 43 and a unit substrate 58 that is fixed by caulking portions 47 formed on the opening surface 45 side of the unit case 43. The microphone unit 32 including the built-in member 53 composed of the above components and the circuit board 62 on which necessary members including a filter and an output circuit are integrally connected and formed are accommodated in the protective case 22 and formed. Has been.

  Among these, the protective case 22 includes a case main body 23 in which the circuit board 62 and the microphone unit 32 are accommodated, and a sound collection opening 25, and is detachably covered on the distal end side of the case main body 23. The cap portion 24 and the base 26 that is disposed on the base end portion side of the case main body portion 23 and is connected to the flexible pipe 72 are configured.

  On the other hand, the circuit board 62 is disposed in a positional relationship orthogonal to the surface direction of the unit board 58 and is provided with a lateral width substantially equal to the outer diameter of the caulking portion 47 of the unit case 43.

  That is, the circuit board 62 has a thin plate-like long quadrilateral shape in which the longitudinal width direction is longer than the length in the lateral width direction, and the position in which the lateral width direction is aligned with the diameter direction of the unit substrate 58. Arranged in a relationship.

  In this case, the necessary members on the circuit board 62 side include a ground pattern 63 for grounding. The ground pattern 63 is located at a position on the circuit board 62 side facing the caulking portion 47 on the microphone unit 32 side when the microphone unit 32 and the circuit board 63 are housed in the protective case 22 based on the above positional relationship. Is provided.

  The positional relationship between the microphone unit 32 and the circuit board 62 will be described in more detail with reference to FIG. 2. The microphone unit 32 includes a unit case 43 with the inner bottom surface 44 side facing the sound collection opening 25, and the unit case. The individual components constituting the built-in member 53 are fixed at predetermined positions in the unit case 43 via the caulking portion 47 formed by bending the open end edge of the opening surface 45 side of the 43 to curl inward. Yes.

  In this case, the components constituting the built-in member 53 include a diaphragm ring 54 provided with a diaphragm 54a stretched and disposed on the inner bottom surface 44 side, a fixed pole 55 provided opposite to the diaphragm 54a, and the fixed member. An insulating seat 56 that supports the pole 55, an FET (impedance converter) 57 that is housed in a space provided in the insulating seat 56 and is electrically connected to the fixed pole 55 side, and the FET 57 is mounted to open the opening 45. A unit substrate 58 to be sealed is included at least.

  Further, the unit case 43 includes a large-diameter portion 46 on the opening surface 45 side in order to hold the unit substrate 58 in a horizontal position in the surface direction when the caulking portion 47 is formed on the open end side. . That is, the unit case 43 is formed with a stepped portion 46a derived from a difference in diameter between the large-diameter portion 46 and the adjacent portion in the length direction, and the stepped portion 46a and the caulking portion 47 are formed. The unit substrate 58 is fixed in position by supporting the opposing peripheral edge of the unit substrate 58 held by the large diameter portion 46.

  Further, the unit case 43 has excellent resistance to a chlorinated organic solvent used for degreasing oils and an acidic solution used for removal of an oxide film, and has good wettability of solder, and is preferably used as a base material. For example, a conductive metal such as C7521 is used.

  On the other hand, the output terminal 57a of the FET 57 protruding as a pair from the unit board 58 to the circuit board 62 side is soldered to a predetermined conductive pattern on the circuit board 62 side. In the illustrated example, only one of the output terminals 57a is shown, and the other is soldered to a predetermined conductive pattern on the back side of the circuit board 62.

  Further, the caulking portion 47 of the unit case 43 is soldered to a ground pattern 63 provided in a positional relationship facing the caulking portion 47 on both end sides in the lateral width direction of the circuit board 62. .

  As a result, the circuit board 62 is soldered to the unit substrate 58 via the output terminal 57a at the substantially central portion along the widthwise direction, and the soldering portions S2 are connected to the caulking portions 47 on both ends. , S2 is integrally connected to the microphone unit 32 side.

  The microphone unit 32 and the circuit board 62 are connected to the sound signal conductive path from the fixed pole 55 on the microphone unit 32 side through the FET 57 to the output circuit on the circuit board 62 side through these soldering portions S. At least a ground-side conductive path for grounding from the unit case 43 side to the ground pattern 63 on the circuit board 62 side is secured, and the condenser microphone 11 is formed in the protective case 22.

  In addition, in the ground side conductive path between the microphone unit 32 and the circuit board 62, the caulking portion 47 of the unit case 43 is electrically connected to a ground pattern (not shown) of the unit board 58, and the circuit board 62 side is connected via the unit board 58. Two paths are secured: one that conducts to the ground pattern 63 and one that the unit case 43 conducts directly to the ground pattern 63 on the circuit board 62 side via the caulking portion 47.

  Next, the operation and effect of the present invention will be described with reference to FIGS. 1 and 2. The microphone unit 32 is mounted on the circuit board 62 arranged in a positional relationship orthogonal to the surface direction of the unit board 58. On the other hand, the unit substrate 58 is soldered via the output terminal 57a of the FET 57 protruding from the unit substrate 58 toward the circuit board 62, and further the unit case 43 is soldered via the caulking portion 47. can do.

  Under such a positional relationship, on the circuit board 62 side, along the surface direction of the unit board 58, the soldering part S1 with the unit board 58 via the output terminal 57a at the substantially central part, and both end parts Separate soldering portions S2 and S2 with the unit case 43 and 35 through the caulking portion 47 are formed.

  On the other hand, the microphone unit 32 and the circuit board 52 are for audio signals that reach the output circuit on the circuit board 62 side from the fixed pole 55 on the microphone unit 32 side via the soldering part S1 on the output terminal 57a side through the FET 57. A conductive path (not shown) is integrated with at least a ground-side conductive path (not shown) extending from the unit case 43 side to the circuit board 52 side via the soldering part S2 on the caulking portion 47 side. It becomes.

  Next, the integrated microphone unit 32 and the circuit board 62 are accommodated in the case main body 23 having an inner diameter dimension substantially equal to the width dimension of the circuit board 62. That is, the circuit board 62 is fed while the long side edge along the length direction is brought into sliding contact with the inner peripheral surface of the case main body 23, so that the case is forced to some extent. It will be stored in the main body 23.

  The cap body 24 is covered with the case main body 23 in which the microphone unit 32 and the circuit board 62 are accommodated, and the condenser microphone 11 is formed by assembling the protective case 22.

  In this case, the circuit board 62 having a thin plate shape swings in a direction orthogonal to the surface direction by forcible push-in at the time of storage, and the swinging pressure is applied via the soldering part S1 at a substantially central part. Therefore, it is supported on the unit substrate 58 side. For this reason, the unit board 58 tends to generate a phenomenon in which the caulking force of the caulking portion 47 is loosened by acting as an insulator with the soldering site S1 as a fulcrum and concentrating stress on the caulking portion 47.

  If such a phenomenon occurs, the unit substrate 58 is inclined in the surface direction, and the caulking portion 47 makes the conductive contact of the unit substrate 58 with a ground pattern (not shown) uncertain. It will be.

  In this case, in the case of the preferred embodiment shown in FIG. 2, the unit case 43 is formed with the large diameter portion 46 on the opening surface 45 side, so that the unit substrate 58 is arranged in the surface direction via the large diameter portion 46. The horizontal position of the unit board 58 is fixed and the unit board 58 can be prevented from acting as an insulator with the soldering part S1 as a fulcrum when stress is applied to the unit board 58 side. ing.

  That is, a stepped portion 46a is generated at the boundary between the large diameter portion 46 and the adjacent portion in the length direction from the difference in diameter between the two, and the stepped portion 46a is a soldered portion S1 of the unit substrate 58. This will prevent the seesaw-like movement around the fulcrum and prevent it from acting as a lever. However, the unit case 43 that does not have a structure such as the large-diameter portion 46 has the caulking force loosened as a result of the unit substrate 58 acting as a lever on the caulking portion 47 to concentrate the stress.

  In the present invention, the circuit board 62 side is soldered to the printed circuit board 58 and is also soldered to the caulking portion 47 so that the circuit board 62 side is integrated with the microphone unit 32 side in a conductive connection. In particular, the caulking portion 47 is directly conductively connected to the ground pattern 63 on the circuit board 62 side via the soldering portion S2.

  Thereby, the ground side conductive path via the caulking portion 47 between the microphone unit 32 side and the circuit board 62 side reaches the ground pattern 63 on the circuit board 62 side through a ground pattern (not shown) on the unit board 58 side. Two paths are ensured, one that leads directly to the ground pattern 63 on the circuit board 62 side.

  Among these, the ground-side conductive path, which is the latter path, is formed by soldering the caulking portion 47 and the ground pattern 63 on the circuit board 62 side, so that the caulking portion is interposed by the soldering part S2. 47 and the ground pattern 63 can be reliably ensured by the surface contact and strong conduction.

  For this reason, loosening of the caulking force occurs between the microphone unit 32 and the circuit board 62, so that the ground-side conductive path from the caulking portion 47 to the unit board 58 becomes an unstable conductive state. However, another ground conductive path from the caulking portion 47 to the ground pattern 63 on the circuit board 62 side can be stably secured.

  Thereby, the condenser microphone 11 can ensure a reliable shielding effect against electromagnetic waves, and can avoid generation of hum noise. In addition, since the diaphragm ring 54 that is electrically connected to the unit case 43 is firmly connected to the circuit board 62 side through the conductive connection between the caulking portion 47 and the ground pattern 63 on the circuit board 62 side, Generation of noise due to poor contact can also be avoided.

  Furthermore, the condenser microphone 11 has a flexible pipe 72 integrally connected to the base end side of the protective case 22 via a base 26, and swings in response to frequent bending of the flexible pipe 72. Thus, even if the caulking force is alleviated, the ground-side conductive path is secured, so that the generation of hum noise can be effectively avoided, and the gooseneck microphone can be suitably used for a long time.

  The above is the description of the present invention based on the illustrated example, and the specific configuration is not limited thereto. For example, the unit case 43 is formed by using C7521, which is a conductive metal. However, the unit case 43 is not limited to this, has conductivity, is excellent in resistance to solvents and acidic liquids, and is wet with solder. Any metal material having good properties can be used as a material for the unit case 43. Further, the shape of the unit case may be the conventional type shown in FIG.

Explanatory drawing which shows the cross-sectional structure about an example of this invention. The enlarged view which shows the principal part about the example shown in FIG. Explanatory drawing which shows the cross-sectional structure about the whole structural example of the conventional capacitor | condenser microphone. Explanatory drawing which expands the part of the condenser microphone of FIG. 3, and shows an example of an internal structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Condenser microphone 22 Protective case 23 Case main-body part 24 Cap part 25 Sound collection opening part 26 Base 32 Microphone unit 43 Unit case 44 Inner bottom face 45 Opening surface 46 Large diameter part 46a Step part 47 Caulking part 53 Built-in member 54 Diaphragm ring 54a Diaphragm 55 Fixed pole 56 Insulator 57 FET (impedance converter)
57a Output terminal 58 Unit board 62 Circuit board 63 Ground pattern 72 Flexible pipe S, S1, S2 Soldering part

Claims (2)

A microphone unit comprising a unit case having a bottomed cylindrical shape, and a built-in member composed of a plurality of parts including a unit substrate that is caulked and sealed via a caulking portion formed on the opening surface side of the unit case, and a filter And a circuit board disposed in a positional relationship perpendicular to the surface direction of the unit board, on which necessary members including the output circuit and the like are mounted, and the microphone unit and the circuit board are interposed via the unit board In the condenser microphone that is integrally housed in the protective case by securing at least the ground side conductive path by soldering each other,
The unit case is formed of a solderable metal material, and the circuit board is provided with a lateral width substantially equal to the outer diameter of the caulking portion of the unit case, and faces the caulking portion when stored. A capacitor microphone, wherein the unit case and the circuit board are firmly connected to each other by soldering the caulking portion and the ground pattern.   The condenser microphone according to claim 1, wherein a flexible pipe is integrally connected to a base end side of the protective case.

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