JP4939352B2 - Condenser microphone unit and manufacturing method thereof - Google Patents

Description

  The present invention relates to a condenser microphone unit that can be suitably incorporated in an acoustic tube as well as an impedance converter and a fixed pole that are electrically connected to each other and a method for manufacturing the same.

  In the condenser microphone unit, a unit case having a bottomed cylindrical shape is caulked with an open edge part that partitions an opening provided on one side so that necessary members including an impedance converter incorporated in the unit case are accommodated and held. Some of them are Since this type of condenser microphone unit can be formed in a small size and light weight, it is adjusted to a single directivity and is often used for a pin microphone or the like.

In this case, as disclosed in Patent Document 1 below, the impedance converter includes a fixed pole side lead terminal (drain terminal, source terminal) that secures electrical continuity with the fixed pole, and a printed circuit board. And a printed circuit board side lead terminal (gate terminal) that secures electrical continuity therebetween, and the main body is housed in a recess provided in the insulating seat under the state of being mounted on the printed circuit board.
Registration No. 3017118 Utility Model Gazette

  FIG. 3 is a longitudinal sectional view showing an example of a conventional structure of a condenser microphone unit including Patent Document 1. According to the figure, the condenser microphone unit 101 has a front acoustic terminal hole 103 on one side and an opening 104 on the other side, and is necessary at a predetermined position in a unit case 102 having a bottomed cylindrical shape. A built-in member is arranged to form the whole.

  The arrangement of the built-in member in the unit case 102 in this case is as follows. The diaphragm 112 is housed under a positional relationship facing the front acoustic terminal hole 103 while being stretched on the support ring 113. A fixed pole 123 is disposed facing the rear of the diaphragm 112 (upward in the illustrated example) with a predetermined interval through a spacer 115. The fixed pole 123 is disposed in parallel to the diaphragm 112 via an insulating seat 125 disposed on the rear side (upper side in the illustrated example), and is attached to the surface of the fixed pole 123 facing the diaphragm 112. The electret material and the diaphragm 112 form a capacitor portion.

  A printed circuit board 134 having an impedance converter 134 mounted on its lower surface is disposed in the opening 104 of the unit case 102 located behind the insulating seat 125 (above in the illustrated example). The opening 104 is sealed by caulking and fixing the opening edge 105 to the upper surface side.

  The impedance converter 134 includes a main body portion 135 disposed in a recess 126 provided in the insulating seat 125, a one-side lead terminal 136 protruding from the main body portion 135 toward the fixed pole 123 side, a printed circuit board It is comprised with the other side lead terminal 137 protruding toward the 133 side.

  In this case, the one-side lead terminal 136 is pulled out from the insertion hole 127 that communicates with the recess 126 and opens the fixed pole 123 side, and is bent to be bent along the surface direction of the fixed pole 123. It is in conductive contact with the fixed pole 123 side via 136a.

  Further, the other-side lead terminal 137 is in conductive contact with the printed circuit board 133 side via a soldered portion 138 that is soldered with the protruding end 137a protruding from the insertion hole 133a of the printed circuit board 133 to the outer surface side. .

  Further, the insulating seat 125 is provided with a through hole 128 at a position facing the plurality of rear acoustic terminal holes 133 b included in the printed circuit board 133. The through-hole 128 communicates with an air chamber 129 defined between the fixed electrode 123 and the closed state by the acoustic resistance material R. Thus, the condenser microphone unit 101 can be provided with a single directivity by ensuring an air path that allows sound waves entering from the rear acoustic terminal hole 133b to reach the diaphragm 112 through the acoustic resistance material R. It will be possible.

  FIG. 4 is an explanatory diagram showing an outline of a process example when manufacturing the condenser microphone unit 102 shown in FIG. 3. According to the figure, as shown in (a), first, the fixed pole 123 is placed on one side of the insulating seat 125, and the main body 135 of the impedance converter 134 mounted is positioned in the recess 126. The printed circuit board 133 is disposed on the other side surface, and the protruding end portion 137a of the other-side lead terminal 137 is fixed to the printed circuit board 133 side by the soldering portion 138. Are combined together.

  As shown in FIG. 5B, the subunit 122 is formed on the side of the support ring 113 facing the fixed electrode 123 in the support ring 113 and the support ring 113 on which the diaphragm 112 disposed on the front acoustic terminal hole 103 side is stretched. The spacer 115 interposed between the two is housed in a unit case 102 that is disposed in advance.

  After the predetermined built-in member is arranged in the unit case 102, the condenser edge is obtained by caulking the opening edge portion 105 to the inside so that the opening portion 104 is sealed as shown in FIG. Unit 101 is formed.

  However, when the condenser microphone unit 101 is manufactured through the steps shown in FIGS. 4A to 4C, the printed circuit board 133 receives a large caulking pressure from the opening edge portion 105 toward the peripheral edge during caulking. . For this reason, the printed circuit board 133 is bent and deformed so that the central portion projects outward, and is lifted from the insulating seat 125.

  At this time, since the protruding end portion 137b of the other side lead terminal 137 of the impedance converter 134 is fixed to the printed circuit board 133 via the soldering portion 138, the bent end portion 136a of the one side lead terminal 136 is formed. As a result that the conductive contact state with the fixed pole 123 side becomes uncertain as a result of being pulled, there is a problem that noise is generated in the condenser microphone unit 101.

  In addition, since the printed circuit board 133 is bent, a gap t is generated between the printed circuit board 133 and the insulating seat 125 as shown in FIG. 3, and enters the unit case 102 through the rear acoustic terminal hole 133b. Then, the introduced air leaks from the recess 126 to the outside through the insertion hole 127.

  In the case where the condenser microphone unit 101 is a pin microphone that is used alone, there is no problem even if such air leakage occurs. However, when a line microphone is formed by being incorporated in an acoustic tube having a large acoustic resistance, there are inconveniences that the directional frequency characteristic varies and the performance such as sensitivity and SN ratio varies greatly.

  The present invention was introduced into the unit case through the rear acoustic terminal hole while ensuring the electrical conduction state between the fixed pole and the impedance converter in view of the above-described problems of the prior art. It is an object of the present invention to provide a condenser microphone unit that can be suitably incorporated into an acoustic tube by preventing air leakage and a method for manufacturing the same.

  The present invention has been made to achieve the above object, and the first invention (manufacturing method) of the present invention includes a one-side lead terminal projecting from one side of the main body and a projecting from the other side. An impedance converter including the other-side lead terminal provided is used, and the impedance converter is electrically connected to the fixed pole side through the one-side lead terminal, and the other-side lead terminal protrudes to the outside. A bottomed cylinder having an opening for a built-in member other than a printed circuit board including the subunit, wherein the main body is disposed in a recess provided in an insulating seat and integrated as a subunit. A second step of filling and sealing the sealing material in the concave portion on the side where the other-side lead terminal protrudes at any time before and after being housed in the unit case, and the built-in unit including the subunit Member After placing the printed circuit board in a state in which the other lead terminal of the impedance converter protrudes from the printed circuit board side in the opening after being accommodated in the knit case, A third step in which the unit case is sealed by caulking to the outer surface side of the printed circuit board; and the other lead terminal protruding from the outer surface side of the printed circuit board after being sealed is soldered to the printed circuit board side The main feature is that at least the fourth step is performed.

  In this case, the insulating seat is provided with a through hole facing the acoustic terminal hole provided in the printed circuit board and communicating with the through hole provided in the fixed electrode, and an acoustic resistance material is disposed in the through hole. You can also

  Further, the second invention (condenser microphone unit) is characterized in that it is manufactured by the manufacturing method according to claim 1 or 2.

  According to the first aspect of the present invention, the subunit is accommodated in the unit case, and the printed circuit board is disposed in the opening portion thereof, and then the caulking is fastened and sealed. One side lead terminal because the other side lead terminal protruding from the outer surface side of the printed circuit board is still in a free state that is not soldered even if it bends and deforms so as to protrude outward and floats up from the insulating seat The conductive contact state between the side and the fixed pole side can be ensured.

  In this state, the other lead terminal protruding from the outer surface side of the printed circuit board is soldered to the printed circuit board side for the first time, resulting in noise caused by poor contact between the one side lead terminal side and the fixed pole side. A condenser microphone unit without generation can be manufactured.

  Moreover, even if the printed circuit board is bent and a gap is formed between the printed circuit board and the insulating seat, the recessed portion of the insulating seat is sealed with a sealing material, so that it is introduced into the unit case through the rear acoustic terminal hole. Leakage to the outside of the air can be reliably prevented, and even when a line microphone with a narrow directivity is formed by incorporating it in an acoustic tube with a large acoustic resistance, variations in directivity frequency characteristics can occur. It is possible to manufacture a condenser microphone unit that does not cause a large variation in performance such as the SN ratio.

  According to the invention of claim 2, the insulating seat has a through hole facing the acoustic terminal hole provided in the printed circuit board and communicating with the through hole provided in the fixed pole, and the acoustic resistance material is provided in the through hole. Since the acoustic terminal hole on the unit case side is the front acoustic terminal hole and the acoustic terminal hole on the printed circuit board side is the rear acoustic terminal hole, the unidirectional condenser microphone unit can be manufactured. Can do.

  In addition, according to the invention according to claim 3, a condenser microphone that is manufactured by the manufacturing method according to claim 1 or 2 and does not generate noise due to poor contact between the one-side lead terminal side and the fixed pole side. Capacitor microphone unit that does not cause fluctuations in directional frequency characteristics even if incorporated into a unit or acoustic tube to form a narrow directivity line microphone, It can be provided as a unidirectional condenser microphone unit.

  FIG. 1 is a longitudinal sectional view showing an example of the structure of a condenser microphone unit according to a second invention manufactured by the manufacturing method according to the first invention. The entire condenser microphone unit 11 has a front acoustic terminal on one side. A unit case 12 having a hole 13 and having an opening 14 partitioned by an opening edge 15 on the other side and having a bottomed cylindrical shape, and a plurality of units arranged separately at predetermined positions in the unit case 12 It is comprised with the built-in member.

  The arrangement state of the built-in member in the unit case 12 in this case is as follows. The diaphragm 22 is housed under a positional relationship facing the front acoustic terminal hole 13 while being stretched on the support ring 23. A fixed pole 33 is disposed facing the rear side of the diaphragm 22 (upward in the illustrated example) with a predetermined interval through a spacer 25. The fixed pole 33 is disposed in parallel to the diaphragm 22 via an insulating seat 35 disposed on the rear side (upper side in the illustrated example), and is attached to the surface of the fixed pole 33 facing the diaphragm 22. The electret material and the diaphragm 22 form a capacitor portion.

  A printed circuit board 42 on which an impedance converter 44 is mounted is disposed on the lower surface of the opening 14 of the unit case 12 located behind the insulating seat 35 (upward in the illustrated example). The opening 14 is sealed by caulking and fixing the opening edge 15 to the upper surface side of the plate.

  The impedance converter 44 includes a main body 45 disposed in a recess 36 provided in the insulating seat 35, a one-side lead terminal 46 projecting from the main body 45 toward the fixed pole 33, and a printed circuit board. It is comprised with the other side lead terminal 47 projected toward the 42 side. In this case, the one-side lead terminal 46 is used as a gate terminal for taking out a signal from the fixed pole 33 side, and only one of the one-side lead terminal 46 is visually seen in the illustrated example. It consists of two.

  In this case, the one-side lead terminal 46 is drawn out from the insertion hole 37 that communicates with the recess 36 and opens the fixed pole 33 side, and is bent along the surface direction of the fixed pole 33. It is in conductive contact with the fixed pole 33 side through 46a.

  Further, the other-side lead terminal 47 is in conductive contact with the printed circuit board 42 side through a soldered portion 48 that is soldered with the protruding end 47a protruding from the insertion hole 42a of the printed circuit board 42 to the outer surface side. .

  Further, the insulating seat 35 is provided with a through hole 38 at a position facing the plurality of rear acoustic terminal holes 42 b provided in the printed circuit board 42. The through-hole 38 communicates with an air chamber 39 defined between the stationary electrode 33 and the acoustic resistance material R. Thereby, the condenser microphone unit 11 is provided with an unidirectionality by ensuring an air path through which the sound waves entering from the rear acoustic terminal hole 42b reach the diaphragm 22 through the acoustic resistance material R. It will be possible.

  2A to 2E are explanatory views showing an outline of a process example when manufacturing the condenser microphone unit 11 shown in FIG. In the present invention, the main body 45 disposed in the recess 36 of the insulating seat 35, the one-side lead terminal 46 projecting from the main body 45 toward the fixed pole 33, and the printed circuit board 42 side. The above-described impedance converter 44 including the other-side lead terminal 47 protruding in this manner is used.

  FIG. 2A shows the first step. The impedance converter 44 is electrically connected to the fixed pole 33 side via the bent end portion 46 a of the one-side lead terminal 46, and the other-side lead terminal 47. The main body 45 is disposed in the recess 36 provided in the insulating seat 35 under the state of projecting to the outside, so that the unit 32 is integrated.

  FIG. 2B shows the second step, and the built-in member other than the printed circuit board 42 including the subunit 32 is accommodated in the bottomed cylindrical unit case 12 having the opening 14. The sealing material 40 is filled in the concave portion 36 on the side from which the other-side lead terminal 47 protrudes at any time before or after, and this is sealed. As the sealing material 40, for example, a one-part room temperature curable silicone rubber such as a product number “KE347” manufactured by Shin-Etsu Chemical Co., Ltd. can be suitably used.

  In this case, as a built-in member other than the printed circuit board 42, a support ring 23 on which a diaphragm 22 disposed on the front acoustic terminal hole 13 side is stretched, a spacer 25, and the second member shown in FIG. There is a subunit 32 integrated in one process. The subunit 32 is accommodated in the unit case 12 after the spacer 25 is interposed between the holding ring 23 positioned on the side facing the fixed pole 33.

  FIG. 2C shows the third step. After the built-in member including the subunit 32 is accommodated in the unit case 12 as shown in FIG. The printed circuit board 42 is disposed in the opening 14 in a state in which the other lead terminal 47 of the impedance converter 44 protrudes from the insertion hole 42a side provided in the printed circuit board 42 as a protruding end 47a. It is done by doing.

  FIG. 2D shows the fourth step. After the printed circuit board 42 is arranged in the opening 14 of the unit case 12 as shown in FIG. 2C, the opening 14 is partitioned. This is done by caulking and fastening the open edge 15 to the outer surface 43 side of the printed circuit board 42 and sealing the unit case 12.

  FIG. 2E shows the fifth step, and the other lead protruding from the outer surface 43 side of the printed circuit board 42 after sealing the unit case 12 as shown in FIG. 2D. This is done by soldering the protruding end portion 47a of the terminal 47 to the printed circuit board 42 side to provide a soldering portion 48, whereby the capacitor microphone unit 11 shown in FIG. 1 can be formed.

  In the case where the acoustic resistance material R is disposed in the plurality of through holes 37 provided in the insulating seat 35, the rear acoustic terminal holes 42b of the printed circuit board 42 in a positional relationship facing the through holes 37, The air volume of the air path reaching the back surface of the diaphragm 22 through the air chamber 39 defined by a predetermined volume applied to the back surface of the fixed electrode 33 and the through hole 34 provided in the fixed electrode 33 is adjusted. can do.

  Next, the operation and effect of the condenser microphone unit 11 manufactured by the method of the present invention will be described with reference to FIG. 1. The protruding end portion 47a of the other-side lead terminal 47 protruding from the outer surface side of the printed circuit board 42 is sub- The unit 32 is accommodated in the unit case 12, and the printed circuit board 42 is disposed in the opening 14, and after caulking and sealing, the unit 32 is sealed and then soldered to the printed circuit board 42 side. Integrated.

  For this reason, the condenser microphone unit 11 effectively avoids a contact failure between the bent end portion 46a of the one-side lead terminal 46 and the fixed pole 33 side even if the printed circuit board 42 is bent so as to be lifted when the caulking is fixed. Therefore, it is possible to give a characteristic without generating noise.

  In addition, since the condenser microphone unit 11 is provided with the insulating seat 35 sealed with the sealing material 40 filled in the concave portion 36, the air introduced into the unit case 12 through the rear acoustic terminal hole 42b. It has a structure that can reliably prevent leakage to the outside.

  For this reason, even if the condenser microphone unit 11 is incorporated into an acoustic tube to form a narrow directivity line microphone, the directivity frequency characteristics vary, and the performance such as sensitivity and SN ratio varies greatly. The characteristic which does not generate | occur | produce can be provided.

  The condenser microphone unit 11 has a through-hole 38 that faces the rear acoustic terminal hole 42 b of the printed circuit board 42 and communicates with the through-hole 34 of the fixed pole 33, and the acoustic resistance material R is in the through-hole 38. In the case where the insulating seat 35 is provided, unidirectionality can be imparted.

  In other words, the condenser microphone unit 11 may be formed with a characteristic that does not generate noise due to poor contact between the one-side lead terminal 46 side and the fixed pole 33 side, or a line microphone with a narrow directivity incorporated in an acoustic tube. It is possible to provide a characteristic that does not cause variations in the directional frequency characteristics, a characteristic that does not cause large variations in performance such as sensitivity and SN ratio, or a unidirectional characteristic.

  The above is the description of the present invention based on the illustrated example, and the specific configuration is not limited thereto. For example, in the illustrated example, a condenser microphone unit adjusted to be unidirectional is shown, but a non-directional condenser microphone unit may be used.

The longitudinal cross-sectional view which shows the structural example of the capacitor | condenser microphone unit which concerns on the 2nd invention manufactured by the manufacturing method which concerns on 1st invention. Explanatory drawing which shows the outline | summary of the process example at the time of manufacturing the capacitor | condenser microphone unit shown in FIG. 1 according to process as (a)-(e). The longitudinal cross-sectional view which shows the example of the conventional structure of a capacitor | condenser microphone unit. Explanatory drawing which shows the outline | summary of the process example at the time of manufacturing the capacitor | condenser microphone unit shown in FIG. 3 according to process as (a)-(c).

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Condenser microphone unit 12 Unit case 13 Front acoustic terminal hole 14 Opening surface 15 Opening edge part 22 Diaphragm 23 Support ring 25 Spacer 32 Subunit 33 Fixed pole 34 Through-hole 35 Insulating seat 36 Recessed part 37 Insertion hole 38 Through Hole 39 Air chamber 40 Sealing material 42 Printed circuit board 42a Insertion hole 42b Rear acoustic terminal 44 Impedance converter 45 Main body 46 One side lead terminal 46a Bend end 47 Other side lead terminal 47a Projection end 48 Soldering part R Acoustic resistance Material

Claims (3)

An impedance converter including one side lead terminal projecting from one side of the main body and the other side lead terminal projecting from the other side is used.
The impedance converter is placed in a recess provided in an insulating seat under a state in which the impedance converter is electrically connected to the fixed pole side through the one side lead terminal and the other side lead terminal protrudes to the outside. And a first step of integrating as a subunit,
Sealing in the concave portion on the side where the other-side lead terminal protrudes at any time before or after the housing member other than the printed circuit board including the subunit is accommodated in the bottomed cylindrical unit case having the opening. A second step of filling and sealing the material;
The printed circuit board is disposed in a state in which the other lead terminal of the impedance converter protrudes from the printed circuit board side in the opening after the built-in member including the subunit is accommodated in the unit case. Then, a third step of sealing the unit case by caulking and fixing the opening side to the outer surface side of the printed circuit board;
A method of manufacturing a capacitor microphone unit, comprising at least a fourth step of soldering the other-side lead terminal protruding from the outer surface side of the printed circuit board to the printed circuit board side after sealing.   The insulating seat is provided with a through hole facing an acoustic terminal hole provided in the printed circuit board and communicating with a through hole provided in the fixed pole, and an acoustic resistance material is disposed in the through hole. 2. A method for producing a condenser microphone unit according to 1.   A condenser microphone unit manufactured by the manufacturing method according to claim 1.

Images