JP2008109212A - Condenser microphone unit and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a condenser microphone unit such that the interval between a diaphragm and a fixed electrode opposed thereto can precisely be set, and a manufacturing method thereof. <P>SOLUTION: The condenser microphone unit comprises the diaphragm 3 held by a diaphragm holder 2, the fixed electrode 5 opposed to the diaphragm and constituting a condenser with the diaphragm 3, and a unit case 1 which stores internal components including the diaphragm 3 and fixed electrode 5. The fixed electrode 5 has its outer peripheral surface fitted in an inner peripheral surface of a ring-shaped insulating seat 4 relatively movably along a center axis, one end surface of the ring-shaped insulating seat 4 presses an outer peripheral edge portion of the diaphragm 3 against the diaphragm holder 2, and the fixed electrode 5 is bonded and fixed to the ring-shaped insulating seat 4 where a predetermined gap is formed with the diaphragm 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a condenser microphone unit and a manufacturing method thereof, and more particularly, to a structure and a manufacturing method capable of appropriately setting an interval between a diaphragm and a fixed electrode.

  The condenser microphone unit mainly includes a film-like diaphragm that receives a sound wave and vibrates, and a fixed electrode that is disposed to face the diaphragm at an appropriate interval. When the diaphragm vibrates, the capacitance of the capacitor formed by the diaphragm and the fixed electrode changes, so that electroacoustic conversion is performed and an audio signal is output. Therefore, in the condenser microphone unit, it is necessary to accurately set and stably maintain the distance between the diaphragm and the fixed electrode, and to maintain a predetermined performance, and a configuration suitable for that is taken. .

8 and 9 show an example of a conventional condenser microphone unit. 8 and 9, the cylindrical unit case 101 has an inward flange 121 on the front end (left end in the figure) side, and has a circular window hole 111 surrounded by the flange 121. In the unit case 101, a diaphragm holder 102, a diaphragm 103 fixed to the rear surface of the diaphragm holder 102, a spacer 108, a fixed electrode 105, and an insulating seat 106 are stacked in order from the front side. It is stored. After each of these built-in components is stored in the unit case 101, the pressing ring 107 is screwed into the screw hole in the inner periphery of the open rear end of the unit case 101, whereby an appropriate pressing force is applied to each of the above members, and the unit case 101 is fixed inside. The diaphragm 103 is fixed to a circular jetty whose peripheral part is formed along the peripheral edge on the rear side of the diaphragm holder 102 so as to vibrate upon receiving a sound wave, with appropriate tension applied thereto. A plurality of holes 112 serving as front acoustic terminals are formed in the main body portion of the diaphragm holder 102 that is opposed to the diaphragm 103 with a space therebetween. The front surface of the outer peripheral edge of the diaphragm holder 102 is in contact with the inner surface (rear surface) of the flange 121 of the unit case 101.

  The spacer 108 is for forming an appropriate gap between the diaphragm 103 and the fixed electrode 105, and is formed by punching a film-like member made of an insulator such as a plastic material into a ring shape. The spacer 108 is interposed between the outer peripheral edge of the diaphragm 103 and the front outer peripheral edge of the fixed electrode 105, and an interval corresponding to the thickness of the spacer 108 is provided between the diaphragm 103 and the fixed electrode 105. It has been. A portion where the spacer 108 and the fixed electrode 105 overlap is a stray capacity. Since the sensitivity as a microphone is lowered when there is a stray capacity, it is desirable that the stray capacity be small. Therefore, in the example shown in FIGS. 8 and 9, a stepped jetty 161 is formed at the front peripheral edge of the insulating seat 106, and the outer periphery of the fixed electrode 105 is surrounded by the jetty 161, and the fixed electrode is formed at the stepped portion of the jetty 161. The rear surface of the outer peripheral edge portion 105 is pushed, and the front surface of the outer peripheral edge portion of the fixed electrode 105 is in contact with a part of the spacer 108. In short, the outer diameter of the fixed electrode 105 is smaller than the outer diameter of the diaphragm holder 102, the contact area between the spacer 108 and the fixed electrode 105 is reduced, and the stray capacity is reduced. In order to finish the surface of the fixed electrode 105 with a predetermined accuracy, the surface of the fixed electrode 105 may be polished after being fixed to the insulating seat 106 by press-fitting or bonding, and then the spacer 108 may be pressed against the diaphragm 103. It is done.

  According to the conventional example shown in FIGS. 8 and 9, a device is devised in which the contact area between the spacer 108 and the fixed electrode 105 is reduced to reduce the stray capacity. However, the distance between the diaphragm 103 and the fixed electrode 105 depends on the thickness of the spacer 108, and therefore depends on the thickness of the film that is the material of the spacer 108, and the above-mentioned distance cannot be set freely. is there.

  10 and 11 show another example of a conventional condenser microphone unit. 10 and 11, the bottomed cylindrical unit case 201 has a portion corresponding to the bottom plate on the front (left side in the figure) side, and a plurality of slit-like grooves 211 are formed on the portion corresponding to the bottom plate. It is formed in the radial direction, and this groove 211 is a front acoustic terminal. In the unit case 201, in order from the front side, the diaphragm holder 202, the diaphragm 203 fixed to the rear surface of the diaphragm holder 202, the spacer 208, and the fixed electrode whose outer periphery is held by the insulating ring 204 205 and an insulating seat 206 are stacked and stored. After housing each of these members in the unit case 201, the pressing ring 207 is screwed into the screw hole in the inner periphery of the open rear end of the unit case 201, so that an appropriate pressing force is applied to each of the above members and the unit case 201. It is fixed inside. The diaphragm 203 is fixed to the surface on the back side of the ring-shaped diaphragm holder 202 with appropriate peripheral tension so as to vibrate upon receiving the sound wave. The front surface of the outer peripheral edge portion of the diaphragm holder 202 is in contact with a step portion 221 formed on the inner peripheral surface near the front of the unit case 201.

  An inward flange 214 is formed at the front end of the insulating ring 204. The outer peripheral edge 215 of the fixed electrode 205 falls from the front side by an amount corresponding to the thickness of the inward flange 214 and forms a step 215, and this step 215 contacts the rear surface of the inward flange 214. It touches. The rear end surface of the fixed electrode 205 contacts the insulating seat 206, and a gap is generated between the rear end surface of the insulating ring 204 and the insulating seat 206. The spacer 208 is in contact with the front end surface of the insulating ring 204, and the fixed electrode 205 is not in contact therewith. In a state where the fixed electrode 205 and the insulating ring 204 are fitted and coupled so that the front surface of the fixed electrode 205 and the front surface of the insulating ring 204 are accurately positioned on the same surface, the front surface of the fixed electrode 205 and the insulating ring 204 are joined. The front side of is polished.

  According to the conventional example shown in FIGS. 10 and 11, since the insulating ring 204 hits the spacer 208, the stray capacity can be reduced. However, also in the case of this conventional example, the distance between the diaphragm 203 and the fixed electrode 205 depends on the thickness of the spacer 208, and therefore depends on the thickness of the film which is the material of the spacer 208, and the distance can be set freely. There is a difficulty that you can not do.

An object of the present invention is to eliminate the problems seen in the above-described conventional condenser microphone unit, and to accurately set the distance between the diaphragm and the fixed electrode facing the condenser microphone and to keep it stable. To provide a unit.
Another object of the present invention is to provide a method of manufacturing a condenser microphone unit that can easily perform an operation of accurately setting a distance between a diaphragm and a fixed electrode facing the diaphragm.

  By the way, there are Patent Document 1 and Patent Document 2 as patent documents describing inventions related to the present invention. The invention described in Patent Document 1 is formed by etching a central portion of a diaphragm made of a semiconductor wafer on which a semiconductor element for taking out a signal is formed and an insulating film formed by vapor deposition on the surface of the diaphragm. The present invention relates to an acoustic sensor including a spacer, a central portion from which an insulating film of a vibration plate is removed, and a back electrode plate formed by etching a metal provided by vapor deposition on a resist provided on the spacer. Patent Document 1 also describes that a spacer formed by vapor deposition and etching on a vibration plate and a back electrode plate are used for an electret microphone.

  Since the invention described in Patent Document 1 can manufacture an electret microphone unit by applying a semiconductor element manufacturing process, the distance between the diaphragm and the fixed electrode can be accurately manufactured, and It can be assumed that the interval can be kept stable. However, the means for solving the problem is completely different from the present invention.

  In the invention described in Patent Document 2, a terminal board on which a diaphragm, a back electrode (fixed electrode), an insulating cylinder, a contact ring, an FET, etc. are fixed is housed in a casing. An insulating member that is interposed between the back surface of the electrode and the surface of the terminal substrate and integrally has an insulating cylinder portion that extends along the inner peripheral surface of the casing and a spacer ring portion that protrudes to the inside of the front end portion of the insulating tube portion. The present invention relates to a condenser microphone in which a ring part is interposed between a diaphragm and a back electrode, and the back electrode, the contact ring, and a casing are insulated by the insulating cylinder part.

  According to the invention described in Patent Document 2, the back electrode and the terminal board can be electrically connected by the contact ring that also serves as a spacer, and the insulating material that insulates the back electrode and the contact ring from the casing. Thus, since it can be used as a spacer for determining the distance between the diaphragm and the back electrode, there is an advantage that the number of parts can be reduced. However, the problem solving means is completely different from the present invention.

JP 2004-147152 A JP 2001-8293 A

  The condenser microphone unit according to the present invention includes a diaphragm that is held by a diaphragm holding body and vibrates by receiving sound waves, and is disposed opposite to the diaphragm with a predetermined gap therebetween. And a unit case that houses the diaphragm and a built-in component including the fixed electrode, and is electrically connected with a change in capacitance between the diaphragm and the fixed electrode caused by the vibration of the diaphragm. A condenser microphone unit for acoustic conversion, wherein the fixed electrode is fitted on the inner peripheral surface of the ring-shaped insulating seat so as to be relatively movable in the central axis direction, and one end surface of the ring-shaped insulating seat is the diaphragm The outer peripheral edge portion of the diaphragm is pressed against the diaphragm holder, and the fixed electrode has one end face of the ring-shaped insulating seat at the outer peripheral edge portion of the diaphragm. In pressing state, the most important feature that is bonded and fixed to the ring-shaped insulator seat in a position to form a predetermined gap between the diaphragm.

  A method of manufacturing a condenser microphone unit according to the present invention is a method of manufacturing a condenser microphone unit having the above-described characteristics, and includes a ring-shaped insulating seat on a flat plate electrode and a ring-shaped insulating member on the inner peripheral side of the ring-shaped insulating seat. A step of placing an elastic plate having a diameter smaller than the inner diameter of the seat, a step of measuring the capacitance between the fixed electrode and the flat plate electrode while pressing the fixed electrode fitted to the ring-shaped insulating seat against the elastic plate; The step of bonding and integrating the ring-shaped insulating seat and the fixed electrode at the position where the measured value of the capacitance becomes a predetermined value, and the unit case with the integrated ring-shaped insulating seat and the fixed electrode together with other members It is characterized by having a process of incorporating in

  According to the condenser microphone unit of the present invention, the fixed electrode is fitted to the inner peripheral surface of the ring-shaped insulating seat so that the outer peripheral surface is relatively movable in the central axis direction, and the ring-shaped insulating seat is the outer peripheral edge of the diaphragm. Since the gap between the diaphragm and the fixed electrode can be set continuously, the gap between the diaphragm and the fixed electrode can be accurately set. It can be set to a gap. After setting the gap, the gap can be stably maintained by bonding the ring-shaped insulating seat and the fixed electrode.

  According to the method for manufacturing a condenser microphone unit according to the present invention, the capacitance between the fixed electrode and the plate electrode is not simply measured, but the measurement is performed by interposing the elastic plate between the fixed electrode and the plate electrode. Therefore, by adjusting the pressing force of the fixed electrode, the capacitance changes to a large or small value, and a desired capacitance position can be easily obtained. Moreover, it can be adjusted any number of times until the adhesive that bonds the ring-shaped insulating seat and the fixed electrode is cured.

Embodiments of a condenser microphone unit and a manufacturing method thereof according to the present invention will be described below with reference to the drawings.
1 to 3 show an embodiment of a condenser microphone unit according to the present invention. 1 to 3, reference numeral 1 denotes a bottomed cylindrical unit case. The bottomed cylindrical unit case 1 has a portion corresponding to the bottom plate on the front side (left side in FIGS. 1 and 2) and the rear side open. A plurality of slit-like grooves 11 are radially formed in a portion corresponding to the bottom plate of the unit case 1, and these grooves 11 serve as front acoustic terminals. In the unit case 1, a diaphragm holding body 2 that integrally holds the diaphragm 3, a ring-shaped insulating seat 4 that integrally holds the fixed electrode 5, and an insulating seat 6 are housed in order from the front. The screw part formed on the outer peripheral surface of the pressing ring 7 is screwed into the screw formed on the inner peripheral surface of the open end side of the unit case 1, so that the pressing ring 7 moves the insulating seat 6 toward the front side of the unit case 1. Is pushing.

  The diaphragm 3 is a circular member made of a film-like material, and its peripheral edge is fixed to the rear surface of the ring-shaped diaphragm holder 2 so as to vibrate upon receiving sound waves. The diaphragm 3 is fixed with an appropriate tension. On the inner periphery of the unit case 1, a step portion 12 is formed by slightly reducing the inner diameter at a position near the front end of the unit case 1, and the front outer peripheral portion of the diaphragm holder 2 hits the step portion 12. It is like that.

  The outer peripheral surface of the fixed electrode 5 is fitted to the inner peripheral surface of the ring-shaped insulating seat 4, and the fixed electrode 5 is movable relative to the ring-shaped insulating seat 4 in the central axis direction. However, as can be seen from an example of the manufacturing method described later in the manufacturing stage of the microphone unit, the relative positional relationship between the ring-shaped insulating seat 4 and the fixed electrode 5 is adjusted, and when the microphone unit is completed, the fixed electrode 5 and The gap between the diaphragm 3 is adjusted to a desired gap, and the fixed electrode 5 and the diaphragm 3 are integrated by bonding. The front end face of the ring-shaped insulating seat 4 presses the outer peripheral edge of the diaphragm 3 against the diaphragm holder 2. The front surface of the fixed electrode 5 recedes from the front surface of the ring-shaped insulating seat 4 so that a predetermined gap is generated between the front surface of the fixed electrode 5 and the diaphragm 3 facing the front surface. The outer peripheral edge of the disc-shaped insulating seat 6 is in contact with the rear end surface of the ring-shaped insulating seat 4. The rear end surface of the fixed electrode 5 is separated from the front surface of the insulating seat 6.

  As is clear from the configuration described above, when the insulating seat 6 is pushed by the holding ring 7, the ring-shaped insulating seat 4, the diaphragm 3 and the diaphragm holder 2 are pushed by the insulating seat 6, and the diaphragm holder 2 is in contact with the stepped portion 12 of the unit case 1, and the members are fixed in the unit case 1 in a state in which a pressing force acts between them. The relative positional relationship of the fixed electrode 5 with respect to the ring-shaped insulating seat 4 is adjusted and integrated by adhesion, and this is incorporated into the unit case 1, whereby a predetermined gap is formed between the diaphragm 3 and the fixed electrode 5. A capacitor is formed between the diaphragm 3 and the fixed electrode 5. Since the relative positional relationship between the ring-shaped insulating seat 4 and the fixed electrode 5 can be adjusted, the gap between the diaphragm 3 and the fixed electrode 5 can be accurately set, and the diaphragm 3 and the fixed electrode 5 can be bonded. By doing so, the gap can be stably maintained.

  Next, an embodiment of a method for manufacturing a condenser microphone unit configured as described above will be described. The manufacturing method according to the present invention is characterized by the adjustment of the relative positional relationship of the fixed electrode 5 with respect to the ring-shaped insulating seat 4 and the integration by adhesion, and will be described step by step focusing on this characteristic portion.

  FIG. 4 shows the first step. The equipment necessary for the manufacturing method according to the present invention is an elastic plate 8, a jig 10 in which the flat plate electrode 9 is embedded from the upper surface side and the upper surface is flush with the upper surface of the flat plate electrode 9, and a capacitance meter (not shown). . The elastic plate 8 is a kind of elastic spacer, and is called “wave diaphragm”. For example, a material in which countless wavy irregularities are formed on PPS (polyphenylene sulfide) resin having a thickness of about 2 μm is used. Can do. As a means for forming an infinite number of minute irregularities on the PPS resin, for example, a means of pressing a nylon mesh and thermoforming it to transfer the shape of the nylon mesh can be used. A gold vapor deposition film having a thickness of about 500 mm is formed on one side of the PPS resin in advance. The elastic plate 8 has a myriad of undulating minute irregularities, so that the thickness (the dimension from the back surface to the upper end of the convex portion) is about 12 μm in a natural state where no load is applied, but the load is applied in the thickness direction. As a result, the protrusions are crushed and the overall thickness is reduced. Since the innumerable irregularities are uniformly formed, the thickness dimension is uniformly changed unless an extremely biased load is applied.

  The elastic plate 8 is formed in a disk shape having an outer diameter slightly smaller than the inner diameter of the ring-shaped insulating seat, and the elastic plate 8 is placed on the flat plate electrode 9 of the jig 10. Further, the ring-shaped insulating seat 4 with the fixed electrode 5 fitted thereon is placed on the plate electrode 9. The ring-shaped insulating seat 4 may be placed first, and then the elastic plate 8 may be placed.

  Next, as shown in FIG. 5, a capacitance meter (not shown) is connected between the terminal A electrically connected to the fixed electrode 5 and the terminal B connected to the jig 10 which is electrically integrated with the plate electrode 9. Then, a load W is applied to the fixed electrode 5 while measuring the capacitance between the fixed electrode 5 and the plate electrode 9. The load W is gradually increased. It is desirable to use some pressing means so that the ring-shaped insulating seat 4 does not float from the upper surface of the jig 10. As the weight W increases, the fixed electrode 5 moves relative to the ring-shaped insulating seat 4 in the direction of the central axis thereof, crushing the elastic plate 8, and the distance between the fixed electrode 5 and the flat plate electrode 9 gradually decreases. Go. Accordingly, the capacitance between the fixed electrode 5 and the plate electrode 9 measured by the capacitance meter gradually increases. Since the capacitance when the interval between the fixed electrode 5 and the flat plate electrode 9 becomes a desired interval is known in advance, when the displayed value of the capacitance meter reaches a predetermined value, the load increases. While the load at that time is maintained, an adhesive is applied between the fixed electrode 5 and the plate electrode 9 and cured to integrate the fixed electrode 5 and the plate electrode 9.

  FIG. 6 shows the state at this time, and the interval between the opposing surfaces of the fixed electrode 5 and the flat plate electrode 9 is accurately set to a predetermined interval. The front end (lower end in FIG. 6) surface of the ring-shaped insulating seat 4 integral with the fixed electrode 5 is in contact with the diaphragm 3 in the state where the unit case 1 is incorporated. In the manufacturing process, the plate electrode 9 corresponds to the diaphragm 3, and the distance between the fixed electrode 5 and the plate electrode 9 is the distance between the fixed electrode 5 and the diaphragm 3 when assembled as a microphone unit. Will be equal. Therefore, the distance between the fixed electrode 5 and the diaphragm 3 can be adjusted with high accuracy before the microphone unit is assembled. Further, since the distance between the fixed electrode 5 and the diaphragm 3 can be adjusted before assembling as a microphone unit, there is an advantage that the distance adjustment is very easy. In addition, since it can be quantitatively measured by a capacitance meter, there is an advantage that the interval between the fixed electrode 5 and the diaphragm 3 can be adjusted with high accuracy and less variation.

  Since the adhesive requires a certain amount of time from application to curing, the fixed electrode 5 and the vibration plate are measured while measuring the capacitance with the adhesive applied between the fixed electrode 5 and the vibration plate 3. The distance between the fixed electrode 5 and the ring-shaped insulating seat 4 can be adjusted while measuring the capacitance as many times as necessary until the adhesive is cured.

  In adjusting the distance between the fixed electrode 5 and the flat plate electrode 9, the elastic plate 8 is interposed between the fixed electrode 5 and the flat plate electrode 9 to measure the capacitance between the fixed electrode 5 and the flat plate electrode 9. . In this case, the concern is that the dielectric constant of the elastic plate 8 does not change when the elastic plate 8 is crushed, or the countless irregularities of the elastic plate 8 are crushed differently each time, and the electrostatic plate 8 That is, the capacitance and the distance between the fixed electrode 5 and the flat plate electrode 9 may not be in a fixed relationship.

The inventor has created a model of the measuring apparatus and verified this point. A fixed electrode is placed on a metal base, a PPS wave diaphragm having a thickness of 2 μm and a gold deposited film formed on one side is placed on the fixed electrode, the deposited film is placed on top, and a glass plate is placed thereon. It was. A capacitance meter was connected between the deposited film of the PPS wave diaphragm and the metal base. 4 weights of 13.4kg are prepared, and when nothing is placed on the glass plate, when 1 weight is placed, when 2 weights are placed, 3 weights are placed. When four weights were placed, the capacitance between the PPS wave diaphragm and the metal base was measured with a capacitance meter. The results are as follows.

In the case of only glass plate 0.597 (μF)
In case of one weight 0.667 (μF)
0.692 (μF) for 2 weights
In the case of 3 weights 0.710 (μF)
In the case of 4 weights 0.719 (μF)

  FIG. 7 is a graph showing the measurement results. The horizontal axis represents load, and the vertical axis represents capacitance. For the load, only the jig, that is, only the glass plate is placed, and the weights are increased to 1, 2, 3, and 4, and the capacitance at that time is plotted. As can be seen from this graph, the capacitance varies linearly from 1 to 3 weights, and therefore the load ranges from about 23 kg to about 70 kg. If a predetermined load is applied within this range, the load is fixed. The interval between the electrode 5 and the plate electrode 9 can be set to a predetermined interval.

  The condenser microphone unit according to the present invention described above and the condenser microphone unit manufactured by the manufacturing method according to the present invention are housed in a microphone case, and other necessary electrical components such as a circuit board and a connector are incorporated therein. Thus, a condenser microphone can be configured.

1 is an exploded longitudinal sectional view showing an embodiment of a condenser microphone unit according to the present invention. It is a longitudinal cross-sectional view of the said Example. It is a front view of the said Example. It is an exploded longitudinal cross-sectional view which shows 1 process of the Example of the manufacturing method of the condenser microphone unit concerning this invention. It is a longitudinal cross-sectional view which shows another process of the Example of the said manufacturing method. It is a longitudinal cross-sectional view which shows another process of the Example of the said manufacturing method. 6 is a graph showing a result of verifying a change in capacitance when an elastic plate is interposed between a fixed electrode and a glass plate and a load applied to the elastic plate is changed in carrying out the method of manufacturing a condenser microphone unit according to the present invention. . It is a longitudinal cross-sectional view which shows an example of the conventional condenser microphone unit. It is a decomposition | disassembly longitudinal cross-sectional view of the said prior art example. It is a longitudinal cross-sectional view which shows another example of the conventional condenser microphone unit. It is a decomposition | disassembly longitudinal cross-sectional view of the said prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Unit case 2 Diaphragm holder 3 Diaphragm 4 Ring-shaped insulating seat 5 Fixed electrode 6 Insulating seat 7 Holding ring 8 Elastic plate 9 Flat plate electrode 10 Jig 11 Sound terminal 12 Step part

Claims (6)

A diaphragm that is held by a diaphragm holder and vibrates by receiving sound waves, a fixed electrode that constitutes a capacitor together with the diaphragm by being opposed to the diaphragm with a predetermined gap, and the diaphragm And a unit case that houses a built-in component including a fixed electrode, and a condenser microphone unit that performs electroacoustic conversion by a change in capacitance between the diaphragm and the fixed electrode caused by the vibration of the diaphragm. ,
The fixed electrode is fitted to the inner peripheral surface of the ring-shaped insulating seat so that the outer peripheral surface is relatively movable in the central axis direction,
One end surface of the ring-shaped insulating seat presses the outer peripheral edge of the diaphragm against the diaphragm holder,
The fixed electrode has a ring-shaped insulation at a position where a predetermined gap is formed between the fixed electrode and the diaphragm in a state where one end surface of the ring-shaped insulating seat presses the outer peripheral edge of the diaphragm against the diaphragm holding body. Condenser microphone unit that is fixed to the seat.   In the unit case, a diaphragm holding body that holds a diaphragm, a ring-shaped insulating seat with a fixed pole fitted on the inner peripheral surface, and an insulating seat that contacts the ring-shaped insulating seat are stored in this order. 2. The condenser microphone unit according to claim 1, wherein each of the built-in components is fixed in the unit case by pressing the insulating seat with a holding ring screwed on the inner peripheral side.   3. The condenser microphone unit according to claim 2, wherein the insulating seat and the fixed electrode are separated from each other. A diaphragm that is held by a diaphragm holder and vibrates by receiving sound waves, a fixed electrode that constitutes a capacitor together with the diaphragm by being opposed to the diaphragm with a predetermined gap, and the diaphragm And a unit case that houses a built-in component including the fixed electrode, and the fixed electrode is fitted on the inner peripheral surface of the ring-shaped insulating seat so as to be relatively movable in the direction of the central axis, and the diaphragm vibrates. A method of manufacturing a condenser microphone unit that performs electroacoustic conversion by changing a capacitance between a diaphragm and a fixed electrode,
On the plate electrode, a step of placing a ring-shaped insulating seat and an elastic plate having a diameter smaller than the inner diameter of the ring-shaped insulating seat on the inner peripheral side of the ring-shaped insulating seat;
Measuring the capacitance between the fixed electrode and the flat plate electrode while pressing the fixed electrode fitted in the ring-shaped insulating seat against the elastic plate;
Adhering and integrating the ring-shaped insulating seat and the fixed electrode at a position where the measured capacitance value is a predetermined value;
A method of manufacturing a condenser microphone unit comprising a step of incorporating an integrated ring-shaped insulating seat and a fixed electrode together with other members into a unit case.   5. The method of manufacturing a condenser microphone unit according to claim 4, wherein the elastic plate is made of a plastic film in which countless wavy irregularities are formed by molding. 5. The position at which the measured value becomes a predetermined value is determined by measuring the capacitance between the fixed electrode and the flat plate electrode until the adhesive that bonds the ring-shaped insulating seat and the fixed electrode is cured. Of manufacturing a condenser microphone unit.

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