JP2004080264A - Method for manufacturing component of electret capacitor microphone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a component in an electret capacitor microphone which can accurately and easily cut a diaphragm. <P>SOLUTION: In the manufacturing method of a component 10 in the electret capacitor microphone, a ring-like member 13 is adhered to a first surface 12a in a thin-film film 12. Then, the tip section of a die 17 having an annular tip section in a tapered sectional shape is pushed into the first surface 12a at the outer periphery of the ring-like member 13 by a specific amount. Then, on a second surface 12b that is the rear of the first surface 12a, a region at the rear side where the ring-like member 13 is adhered to the first surface 12a is pressed by a punch 18 where the outer diameter of the tip section is smaller than that of the ring-like member 13, thus accurately and easily cutting the thin-film film 12 along the periphery of the ring-like member 13 and manufacturing the component 10. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a component of an electret condenser microphone.
[0002]
[Prior art]
Conventionally, as a technique in such a field, a technique described in Patent Application Publication No. 5-78999 or Patent No. 3199369 is known. The technology described in Patent Application Publication No. 5-78999 discloses a technique in which a ring is attached to a thin film, and the surface on the opposite side of the thin film to which the ring is attached is pressed against an upper mold having a cross section with a slope. By sandwiching the thin film between the ring and the upper die, the thin film is cut from the edge of the ring. Then, the vibrating membrane is taken out by vacuum-sucking the surface of the thin film opposite to the surface to which the ring is attached using a vacuum suction head, and the thin film is pressed by a stripper pin attached to the vacuum suction head. This further cuts the thin film that could not be cut by sandwiching the ring and the upper die.
[0003]
In addition, the technology described in Japanese Patent No. 3199369 discloses a technique in which a ring is attached to a thin film, and an annular cutting edge is applied to the outer periphery of the ring on the side of the thin film on which the ring is attached. The thin film is cut by being sandwiched between the annular cutting edge and the opposing surface by abutting the surface of the thin film on the opposing surface having the curved concave portion.
[0004]
[Problems to be solved by the invention]
In the two prior arts described above, in order to cut the thin film, the clearance between members sandwiching the thin film requires precision. In particular, in order to reduce the size of the electret condenser microphone, it is necessary to reduce the thickness of the diaphragm. Therefore, as the thin film is made thinner, it is necessary to control the clearance with higher precision, but this precision is also limited. As a result, there has been a problem that a part that cannot be completely cut remains in the thin film.
[0005]
The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a method for manufacturing a component member of an electret condenser microphone that can cut a thin film, that is, a vibrating film accurately and easily. And
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a method for manufacturing a component of an electret condenser microphone according to the present invention is directed to an electret condenser microphone having a component including a vibration film and a ring-shaped member attached to the vibration film. A first step of bonding the ring-shaped member to a first surface of the vibrating membrane, and an outer diameter of the ring-shaped member on the first surface; A second step of supporting the tip having a tip portion larger than the outer diameter of the ring member, and, on the second surface of the vibrating membrane, a position on the back side to which the ring member is adhered, And a third step of breaking the vibrating film by pressing the punch having a tip having an outer diameter smaller than the outer diameter.
[0007]
According to the present invention, the ring-shaped member is bonded to the first surface of the vibrating membrane (first step), and the first surface on the outer periphery of the ring-shaped member is attached to the tip having an inner diameter larger than the outer diameter of the ring-shaped member. Supported by the tip of a die having a portion (second step). Then, on the second surface of the vibrating membrane, the back side where the ring-shaped member is adhered to the first surface is pressed by the tip of a punch having a tip with an outer diameter smaller than the outer diameter of the ring-shaped member. Then, the vibrating membrane is broken (third step). As described above, when the position of the back surface of the vibrating membrane to which the ring-shaped member is attached is pressed by the punch having an outer diameter smaller than the diameter of the ring-shaped member, the vibrating membrane breaks from the boundary bonded to the ring-shaped member. In addition, the vibration film can be cut with high precision along the periphery of the ring-shaped member. In addition, since it is not necessary to manage the clearance as in the above-described related art, the diaphragm can be easily cut. In addition, since the periphery of the ring-shaped member can be supported by the die on the first surface to which the ring-shaped member is attached, elongation of the vibrating membrane in the outer region supported by the die can be suppressed.
[0008]
In the method for manufacturing a component of an electret condenser microphone according to the present invention, the cross section of the distal end portion of the die has a tapered shape in which a distance between an inner diameter and an outer diameter of a ring shape becomes narrower toward the distal end. It is preferred to do so.
[0009]
According to the present invention, since the tip of the die has a tapered shape, the area where the vibration film contacts the die can be reduced when the vibration film is pressed in the third step. In addition, by making the tip portion tapered, the slip between the vibrating film and the die when the vibrating film is pressed by the punch can be reduced, so that the vibrating film can be stably cut.
[0010]
In the method for manufacturing a component of an electret condenser microphone according to the present invention, it is preferable that, in the second step, the first surface is pushed in and supported by the tip of the die by a predetermined amount.
[0011]
According to this invention, the first surface of the vibrating membrane is pushed in by a predetermined amount at the tip of the die, so that the vibrating membrane located in the region surrounded by the inner periphery of the tip of the die is uniformly stretched. Can be. As a result, when the second surface of the diaphragm is pressed by the punch in the third step, the thin film can be cut more uniformly along the periphery of the ring-shaped member. Further, when the vibration film is pressed by the punch, the slip between the die and the vibration film can be further reduced.
[0012]
In the method of manufacturing a component of an electret condenser microphone according to the present invention, the tip of the punch has a shape whose outer diameter is smaller than the outer diameter of the ring-shaped member and whose inner diameter is larger than the inner diameter of the ring-shaped member. Then, on the second surface of the vibrating membrane, a position on the back side defined between the inner diameter and the outer diameter of the ring-shaped member bonded to the first surface is pressed by the tip of the punch. It is preferable to be characterized in that:
[0013]
According to the present invention, the tip of the punch has an outer diameter smaller than the outer diameter of the ring-shaped member and an inner diameter larger than the inner diameter of the ring-shaped member. The tip of such a punch presses a position on the second surface of the vibrating membrane on the back side defined between the inner and outer diameters of the ring-shaped member, so that it is surrounded by the inner periphery of the ring-shaped member. Damage to the vibrating membrane located in the region that is located can be prevented.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
A method for manufacturing a component of an electret condenser microphone according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description of the embodiments, in order to facilitate understanding of the description, the same components are denoted by the same reference numerals as much as possible in each drawing, and redundant description will be omitted. Also, the dimensional ratios in the drawings do not always match those described.
[0015]
FIG. 1 is a flowchart of a method for manufacturing a component of an electret condenser microphone according to the present embodiment. FIG. 2 is a cross-sectional view illustrating a process of generating components in the method for manufacturing a component of the electret condenser microphone according to the present embodiment.
[0016]
As shown in FIGS. 1 and 2A, in the method for manufacturing a component member of an electret condenser microphone according to the present embodiment, first, a first thin film 12 made of PET having a thickness of 1.5 μm and made of PET is made of Au. A ring-shaped member 13 having a ring shape of 8.23 mm in outer diameter and 4 mm in inner diameter, which is obtained by applying Ni plating to phosphor bronze, is attached to the surface 12a of the substrate by using an epoxy adhesive (step S1).
[0017]
Next, as shown in FIGS. 1 and 2 (b), the first surface 12a of the thin film 12 is pushed up by a predetermined amount by the die 17 on the outer periphery of the ring-shaped member 13 (step S2). The die 17 has a cylindrical distal end whose inner diameter is larger than the outer diameter of the ring-shaped member 13. In addition, the cross-sectional shape of the distal end portion is a tapered shape in which the distance between the inner diameter and the outer diameter decreases toward the distal end. That is, the cross section has a blade shape.
[0018]
When the thin film 12 is supported by such a tip of the die 17, a portion where the thin film 12 is stretched when the thin film 12 is pressed by the punch 18 as described later can be localized. Thus, when a large number of ring-shaped members 13 are arranged and bonded to one sheet-shaped thin film 12, and when a large number of vibrating films are manufactured, the thin film 12 is cut along the periphery of one ring-shaped member 13. Also, it is possible to avoid affecting the thin film 12 at the portion where the other ring-shaped members 13 are bonded.
[0019]
In addition, by making the cross-sectional shape of the tip of the die 17 tapered, the contact area between the tip of the die 17 and the thin film 12 can be reduced, and the thin film 12 and the die 17 can be better caught. be able to. By pushing the thin film 12 by a predetermined amount by the die 17, the thin film 12 located in a region surrounded by the inner periphery of the tip of the die 17 can be stretched. Accordingly, when the thin film 12 is pressed by the punch 18 in a step described later, the thin film 12 can be uniformly broken along the periphery of the ring-shaped member 13.
[0020]
Next, as shown in FIGS. 1 and 2C to 2E, a punch is formed on the second surface 12b of the thin film 12 at a position on the back side where the ring-shaped member 13 is attached to the first surface 12a. After positioning the tip of the thin film 18 (FIG. 2C), the thin film 12 is pressed by the punch 18 (FIG. 2D). Then, as shown in FIG. 2E, the thin film 12 is broken along the periphery of the ring-shaped member 13 (Step S3). Here, the tip of the punch 18 has an inner diameter larger than the inner diameter of the tip of the ring-shaped member 13 and an outer diameter smaller than the outer diameter of the tip of the ring-shaped member 13. When the tip of the punch 18 is formed into such a shape and the second surface 12b is pressed from a position on the back side of the region surrounded by the inner circumference and the outer circumference of the ring-shaped member 13, the punch 18 is surrounded by the inner circumference of the ring-shaped member 13. It is possible to cut the thin film 12 without damaging the thin film 12 located in the region.
[0021]
As described above, according to the method of manufacturing the component of the electret condenser microphone according to this embodiment, the thin film 12 can be accurately and easily formed from the boundary bonded to the ring-shaped member 13, that is, from the periphery of the ring-shaped member 13. Can be cut. Therefore, it is possible to easily manufacture the components of the electret condenser microphone including the vibrating membrane (the thin film 12 left on the ring-shaped member 13) and the ring-shaped member 13 attached thereto.
[0022]
The present invention can be variously modified without being limited to the above embodiment. For example, the thickness and material of the thin film 12 and the dimensions of the ring-shaped member 13 are not limited to those described in the above embodiment, and can be changed. In addition, by appropriately changing the dimensions of the die 17 and the punch 18 according to these changes, it is possible to apply the method for manufacturing a component member of an electret condenser microphone according to the present invention.
[0023]
Further, in the above embodiment, the cross-sectional shape of the tip of the die 17 is tapered. For example, even if a cylindrical die 17 having a uniform inner diameter and outer diameter from the body to the tip is used, a thin film film may be used. Twelve cuts are possible. However, the die 17 described in the above-described embodiment having the tapered tip portion, in which the area of the tip portion in contact with the thin film film 12 has a small area and is easily caught by the thin film film 12, is better than that of the electret condenser microphone of the present invention. It is more preferable in the method of manufacturing a component.
[0024]
In addition, even if the thin film 12 is supported by pressing the thin film 12 without pushing the thin film 12 at the tip of the die 17, for example, by contacting the tip with the thin film 12, the thin film 12 is pressed by the punch 18. Can be cut. However, the above embodiment, in which the thin film 12 is pushed in at the tip of the die 17 and the thin film 12 in the region surrounded by the tip of the die 17 can be stretched uniformly, is more suitable for the electret condenser microphone of the present invention. It is more preferable in the method of manufacturing a component.
[0025]
The shape of the tip of the punch 18 does not need to be ring-shaped. However, the punch 18 of the above embodiment, which has a lower possibility of damaging the thin film 12 located in the region surrounded by the inner periphery of the ring-shaped member 13, is more suitable for manufacturing components of the electret condenser microphone of the present invention. It is more suitable in the method.
[0026]
Lastly, the configuration of an example of an electret condenser microphone using a component (hereinafter, referred to as a “diaphragm subassembly”) manufactured by the manufacturing method according to the above-described embodiment will be described. FIG. 3 is a perspective view showing the entire appearance of the electret condenser microphone 1 according to the example, FIG. 4 is a cross-sectional view of the electret condenser microphone 1, and FIG. It is an exploded perspective view shown.
[0027]
The electret condenser microphone 1 has a case 2. The case 2 has a bottom surface 3 used as a front plate at one end, and is made of a cylindrical metal (for example, stainless steel) member having an open end at the other end. ) Is formed in a cylindrical shape. An opening 4 having a predetermined shape (for example, a circular shape) is formed in the bottom portion 3 of the case 2. In the case 2, the diaphragm sub-assembly 10, the spacer 21, the back electrode 31, the insulating bush 41, the substrate 51, and the fixing ring 61 are accommodated and arranged.
[0028]
The diaphragm subassembly 10 is a component manufactured by the manufacturing method according to the above-described embodiment, and includes a diaphragm 12 (diaphragm) and a ring-shaped member 13. At the center of the diaphragm 12, a vent hole (through-hole) 14 for adjusting the atmospheric pressure inside and outside the electret condenser microphone 1 is provided. The diameter of the vent hole 14 is set to about 65 μm.
[0029]
The outer diameter of the ring-shaped member 13 is set smaller than the inner diameter of the case 2. The outer diameter of the ring-shaped member 13 is set to 8.23 mm as described above, and the inner diameter of the case 2 is set to 8.5 mm.
[0030]
A ring-shaped positioning projection 15 is integrally formed on the surface of the ring-shaped member 13 on the side opposite to the surface on which the vibration film 12 is adhered (back side). The positioning projection 15 is provided at a position corresponding to the opening 4 of the bottom surface 3, and fits into the opening 4 of the bottom surface 3 when the ring-shaped member 13 is disposed in the case 2. Thus, the positioning of the diaphragm subassembly 10 (the ring-shaped member 13) with respect to the case 2 is performed by fitting the positioning protrusion 15 into the opening 4 of the bottom surface portion 3. Further, a sound hole 16 is formed in an inner peripheral portion of the positioning protrusion 15 of the ring-shaped member 13.
[0031]
In a state where the diaphragm subassembly 10 (the ring-shaped member 13) is disposed in the case 2 and the positioning protrusion 15 is fitted to the opening 4, as shown in FIG. A predetermined gap is provided between the case 2 and the inner peripheral surface. When the positioning projection 15 is fitted into the opening 4 of the bottom surface 3, the surface of the ring-shaped member 13 opposite to the surface on which the vibration film 12 is adhered and the bottom surface 3 come into contact with each other. The ring-shaped member 13 and the case 2 are electrically connected.
[0032]
The back electrode portion 31 is disposed on the rear side of the diaphragm subassembly 10, that is, on the opening (the other end) side of the case 2 with respect to the diaphragm subassembly 10, and as shown in FIG. , An electret 33. The electret 33 is made of a FEP (Fluorinated Ethylene Propylene) film. The back electrode plate 32 is made of a substantially triangular metal (for example, stainless steel) member, and has an electret 33 thermally fused (laminated) to one surface. The back electrode portion 31 is disposed such that the surface of the back electrode plate 32 on which the electret 33 is thermally fused faces the vibration film 12 of the diaphragm subassembly 10. The back electrode plate 32 is disposed in the case 2 so that the center position of the back electrode portion 31 (back electrode plate 32) matches the center position of the case 2, and the inner peripheral surface of the case 2 and the back electrode plate The size is set such that a predetermined gap (for example, about 0.1 mm) is formed between the end portion 32 and the end portion.
[0033]
The back electrode portion 31 is formed by punching a base material, which will constitute the back electrode plate 32, to which an electret 33 is heat-sealed into a substantially triangular shape. After the back electrode portion 31 is formed by punching, the electret 33 is corona-charged so as to have a predetermined surface charge (for example, about -360 V).
[0034]
A spacer 21 is provided between the back electrode part 31 and the diaphragm subassembly 10. The spacer 21 is made of stainless steel or the like, and the thickness of the spacer 21 is set to about 40 μm. As a result, the diaphragm 12 and the back electrode plate 32 (electret 33) are arranged with a predetermined interval (about 40 μm) via the spacer 21. The vibrating membrane 12 and the back electrode plate 32 form a capacitor section.
[0035]
The insulating bush 41 is made of resin, elastomer, or the like, and is pressed into the case 2. The insulating bush 41 is made of PTFE (Polytetrafluoroethylene). The insulating bush 41 is disposed on the rear side of the back electrode portion 31, that is, on the opening side of the case 2 relative to the back electrode portion 31, and is in contact with the surface of the back electrode plate 32 on the opening side of the case 2. .
[0036]
The insulating bush 41 is deformed by applying a predetermined force from the opening side of the case 2 and fits into a gap formed between the inner peripheral surface of the case 2 and the end of the back electrode plate 32. Since the insulating bush 41 is fitted between the inner peripheral surface of the case 2 and the end of the back electrode plate 32, the back electrode plate 32 and the case 2 are electrically insulated from each other. The (back electrode portion 31) is positioned with respect to the case 2.
[0037]
The substrate 51 has a JEFT (Junction Field-Effect Transistor) chip 52 as an impedance converter for converting a change in capacitance between the vibrating membrane 12 and the back electrode plate 32 (capacitor portion) into an electrical impedance. Is established. A gate electrode 53 is formed on the upper surface of the JEFT chip 52. The gate electrode 53 is adhered and fixed to the back electrode plate 32 by a conductive adhesive 54, and the back electrode plate is 32.
[0038]
On the back surface of the substrate 51 (the surface opposite to the surface on which the JEFT chip 52 is provided), power supply terminal pins 55, output terminal pins 56, and ground terminal pins 57 are provided upright. The ground terminal pin 57 is electrically connected to the diaphragm 12 via the case 2. The power terminal pin 55 and the output terminal pin 56 are electrically connected to a drain electrode (not shown) and a source electrode (not shown) of the JEFT chip 52, respectively.
[0039]
The fixing ring 61 is disposed on the rear side of the substrate 51, that is, on the opening side of the case 2 with respect to the substrate 51, and contacts the rear surface of the substrate 51 (the surface opposite to the surface on which the JEFT chip 52 is disposed). In contact. The fixing ring 61 is made of stainless steel or the like. The fixing ring 61 and the case 2 are fixed to each other by laser welding or the like while applying a predetermined force to the fixing ring 61 from the opening side of the case 2.
[0040]
The electret condenser microphone 1 is configured as described above, and the constituent member 10 manufactured by the manufacturing method according to the present embodiment is used as the diaphragm subassembly 10.
[0041]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to cut | disconnect a vibration film accurately and easily from the periphery of the ring-shaped member adhered to the vibration film. As a result, it is possible to easily manufacture the constituent members of the electret condenser microphone including the vibration film and the ring-shaped member attached to the vibration film.
[Brief description of the drawings]
FIG. 1 is a flowchart of a method for manufacturing a component of an electret condenser microphone according to an embodiment.
FIG. 2 is a cross-sectional view showing a process of generating a component by a method of manufacturing a component of the electret condenser microphone according to the embodiment.
FIG. 3 is a perspective view showing an overall view of an electret condenser microphone.
FIG. 4 is a sectional view of an electret condenser microphone.
FIG. 5 is an exploded perspective view showing a configuration of an electret condenser microphone.
FIG. 6 is an exploded perspective view showing a configuration of a back electrode part included in the electret condenser microphone.
[Explanation of symbols]
10: constituent member (diaphragm subassembly), 12: thin film (vibrating film), 12a: first surface, 12b: second surface, 13: ring-shaped member, 17: die, 18: punch

Claims (4)

In a method for manufacturing the structural member, in an electret condenser microphone having a structural member including a vibration film and a ring-shaped member attached to the vibration film,
A first step of bonding the ring-shaped member to a first surface of the vibration film;
A second step of supporting the outer periphery of the ring-shaped member on the first surface by the tip of a die having a tip whose inner diameter is larger than the outer diameter of the ring-shaped member;
On the second surface of the vibrating membrane, the position on the back side where the ring-shaped member is bonded is pressed by the tip of a punch having a tip with an outer diameter smaller than the outer diameter of the ring-shaped member, And a third step of breaking the vibrating membrane. A method for manufacturing a component member of an electret condenser microphone, comprising: The configuration of the electret condenser microphone according to claim 1, wherein a cross section of the distal end portion of the die has a tapered shape in which a distance between an inner diameter and an outer diameter of a ring shape becomes smaller toward the distal end. Manufacturing method of the member. 3. The method according to claim 1, wherein in the second step, the first surface is pressed and supported by a predetermined amount by the tip of the die. 4. The tip of the punch has a shape whose outer diameter is smaller than the outer diameter of the ring-shaped member and whose inner diameter is larger than the inner diameter of the ring-shaped member,
On the second surface of the vibrating membrane, a position on the back side defined between the inner diameter and the outer diameter of the ring-shaped member bonded to the first surface is pressed by the tip of the punch. A method for manufacturing a component of an electret condenser microphone according to any one of claims 1 to 3, characterized in that:

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