JPH1141683A - Small-sized microphone assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a soldering work unnecessary and to simplify an assembling work by integrating a metal fine line orientation type anisotropic electric conductive rubber connector which is held and fixed in a way in which it contacts surfaces of a small- sized microphone body, a vibration proof rubber molding for covering this and a small-sized microphone body electrode part. SOLUTION: A small-sized microphone assembly 1 consists of a small-sized condenser microphone body 11, a metal fine line orientation type anisotropic electric conductive rubber connector 13 and a vibration proof rubber molding 12. In a sheet of the connector 13 of a disk shape on electrode surface side, a metal fine line 14 is embedded and arranged so that it touches two electrodes arranged in a center circle shape of the microphone body 11. After the vibration proof rubber molding 12 is mounted to the microphone body 11, the connector 13 is engaged in the rubber molding 12 on the electrode surface side of the microphone body 11, then held and fixed with the elastic force of the molding 12. Therefore, the connector 13 touches the surface of the electrode part of the microphone body 11 and the microphone body 11 and the connector 13 are integrated. Thus, a mounting of the small-sized microphone assembly 1 is performed only by making the connector 13 press contacted on the surface of an electrode part on a circuit substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a small microphone assembly suitable for being incorporated in a main body of a small communication device represented by a portable telephone and a portable radio device.

[0002]

2. Description of the Related Art At present, small portable communication devices are mainly developed to be smaller and lighter in weight, and a microphone element body used as one component thereof is becoming smaller. Among them, the mounting of a small microphone involves soldering a thin lead wire to connect the electrode on the small microphone side to the electrode on the circuit board inside the small communication device body, and then using a rubber molded product as a waterproof seal. The one covered by a small microphone is built into a small communication device.

[0003]

However, the method of assembling a small microphone for soldering a thin lead wire is as follows.
There are two problems that the soldering work is fine, the work is difficult to automate, and the work is difficult and the work is manual work. Therefore, there is a lack of quality stability and that the mounting space cannot be narrowed because the lead wires are provided.

In order to solve the above-mentioned problems of the prior art, the present invention simplifies the assembling work by eliminating the soldering work, and the metal wire oriented anisotropic conductive material for a mounting method capable of extremely reducing the mounting space. An object of the present invention is to provide a small microphone assembly using a conductive rubber connector.

[0005]

In order to achieve the above object, a small microphone assembly according to the present invention covers a small microphone body with a rubber molded product for vibration isolation, and uses a thin metal wire oriented type anisotropic conductive rubber. The connector is pinched and fixed so as to be in surface contact with the electrode portion of the small microphone main body, and the small microphone main body, a rubber molded product for vibration isolation covering the small microphone main body, and a thin metal wire oriented type anisotropic conductive rubber connector are integrated. It is characterized by being. According to this configuration, the small microphone assembly of the present invention can be assembled simply by pressing against the electrode portion on the circuit board, and the soldering operation and the operation of arranging the lead wires can be omitted. Also, the mounting space can be reduced.

[0006] In the above construction, it is preferable that the rubber molded product for vibration isolation is made of silicone rubber. This is because it has high durability and excellent vibration damping properties.

In the above configuration, it is preferable that the thin metal wires included in the thin metal wire-oriented anisotropic conductive rubber connector are oriented so as to penetrate in the thickness direction of the rubber connector. This is because electrical connection between the electrode portion of the small microphone body and the electrode portion of the circuit board can be made simple and reliable, and the mounting space can be reduced. Note that the orientation in which the thin metal wire penetrates in the thickness direction of the rubber connector means that the straight metal wire is embedded in the thickness direction of the rubber connector, and the thin metal wire is exposed on both end surfaces. means.

In the above configuration, it is preferable that the thin metal wire included in the thin metal wire-oriented type anisotropic conductive rubber connector is embedded so as to match the shape of the electrode portion of the small microphone body. By embedding the fine metal wire only in the portion corresponding to the electrode portion of the small microphone body, a short circuit between adjacent electrodes can be reliably prevented, and the reliability is improved.

In the above structure, the rubber member of the fine metal wire oriented anisotropic conductive rubber connector may be polybutadiene, natural rubber, polyisoprene, butadiene-styrene copolymer (SBR), butadiene-acrylonitrile copolymer ( NBR), ethylene-propylene-non-conjugated diene copolymer (EPDM), ethylene-propylene copolymer (EPM), polyurethane polyester rubber,
Examples thereof include chloroprene rubber, epichlorohydrin rubber, and silicone rubber, and silicone rubber is most preferable from the viewpoint of electrical characteristics and weather resistance.

In the above structure, the fine metal wires of the fine metal wire oriented anisotropic conductive rubber connector include fine wires of stainless steel, copper, nickel, iron, solder, aluminum and zinc, and noble metals such as gold, silver and copper. Can be mentioned, but a thin wire of stainless steel or nickel is preferably plated with gold on the entire surface. This is because good electrical conductivity is obtained and the corrosion resistance is also excellent.

In the above structure, it is preferable that the diameter of the thin metal wire included in the thin metal wire orientation type anisotropic conductive rubber connector is 0.010 to 0.030 mm. If the thin metal wire is thinner than this, the mechanical strength of the thin metal wire may decrease, and sufficient electrical connection may not be obtained when pressed against the electrode surface. On the other hand, if the metal thin wire is thicker than this, the elastic retention effect of the small microphone body by the rubber connector and the rubber molded product for vibration isolation is not sufficiently exhibited, and the electrical connection with the electrode surface is partially reduced. And the conductivity may be reduced.

In the above structure, it is preferable that the burying density of the fine metal wires included in the thin metal wire oriented anisotropic conductive rubber connector is 5 to 30 wires / mm ² at the highest density portion. If the burying density is lower than this, electrical connection with the electrode surface may be insufficient. On the other hand, if the burying density is higher than this, adjacent metal wires will come into contact with each other to cause a short circuit, or if the rubber connector and the rubber molded product for vibration isolation do not sufficiently exert the elastic holding effect of the small microphone body. There is. It is needless to say that the portion having the above density is used so as to make surface contact with the electrode portion.

In the above structure, it is preferable that the thin metal-wire-oriented anisotropic conductive rubber connector has compressive elasticity and can be assembled by being brought into surface contact with the electrode portion on the circuit board. The rubber connector is compressed between the electrode portion of the small microphone main body and the electrode portion of the circuit board, and is elastically deformed appropriately to be incorporated, so that the rubber connector comes into surface contact between the two electrode portions. This is because the thin metal wire in the rubber connector can be reliably electrically connected to both electrodes.

The compression elasticity of the rubber part at this time is determined according to JIS.
In the method A of K6301, it is preferably in the range of 20 to 70. When the compression elasticity is smaller than the above range, the elastic deformation of the rubber connector becomes large, and the electrical connection with the circuit board electrode becomes unstable due to contact between the thin metal wires. If the compression elasticity is larger than the above range, the elastic deformation of the rubber connector is small, so that the reliability of the electrical connection between the thin metal wire in the rubber connector and the electrode portion of the small microphone body or the electrode portion of the circuit board is reduced. There is a risk. Note that J
The measurement of the compression elasticity described in the method A of IS K6301 is as follows. As a sample, a test piece having a size specified in JIS K6301 is prepared and used as a sample. The measuring tool is
Use an A-type spring hardness tester conforming to JIS K6301. The method A of JIS K6301 is AST
Conforms to type A of MD2240.

Although the small microphone assembly of the present invention is used for various applications, it is preferable that the microphone assembly is used by being incorporated in the main body of a small portable communication device such as a portable telephone. The small microphone assembly of the present invention eliminates the need for soldering work using lead wires, thereby reducing the mounting space, and the small microphone body is pressed and held between a rubber molded product for vibration isolation and a rubber connector. By doing so, the reliability and vibration resistance of the electrical connection are improved at the same time, so that the commercial value of a small portable communication device that is particularly required to be reduced in size and improved in reliability can be improved.

In the small microphone assembly using the metal thin wire-oriented anisotropic conductive rubber connector having the above-described structure, the metal thin wire-oriented anisotropic conductive rubber connector is connected to the electrode surface of the small microphone body and the inside of the small communication device body. Reliable electrical connection can be made by only lightly compressing the surface of the electrode on the circuit board, conducting only in the thickness direction of the rubber connector, and having insulating anisotropic conductivity in the lateral direction On top of that, a thin metal wire is buried only on the electrode surface, so a highly reliable electrical connection can be obtained.In addition, complicated rubber connector alignment is not required, and multiple circuits can be connected with one rubber connector. Since connection is possible, circuit connection for soldering lead wires becomes unnecessary, so that not only the mounting space can be reduced, but also troublesome mounting work can be omitted.

In addition, a rubber molded product for vibration isolation called a bush covers all parts other than the electrode surface and the sound collecting portion of the small microphone body in an airtight manner, and furthermore, a metal thin wire oriented anisotropic conductive rubber connector which is in surface contact with the electrode. Since it has a shape that can be pinched and fixed at the same time, it is possible to integrate the small microphone body and the metal thin wire oriented anisotropic conductive rubber connector. Just assembling the used small microphone assembly at a predetermined location in the small communication device, the small microphone can be mounted,
The work efficiency in the assembly work can be greatly improved.

In addition, by using a rubber molded product for vibration isolation called a bush, not only the vibration isolation reliability of the small microphone main body, but also in a small communication device in which the small microphone assembly is incorporated. Since the surface pressure between the microphone electrode surface and the circuit board electrode surface is fixed at a constant pressure by the rubber elasticity of the bush, a synergistic effect that a highly reliable electrical connection can be achieved is exhibited.

[0019]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

FIG. 1A (plan view) and FIG. 1B (I-
1C (bottom view), in one embodiment shown in FIG. 1C (bottom view), the small microphone assembly 1 includes a small condenser / microphone main body 11, a thin metal wire oriented anisotropic conductive rubber connector 13 and an anti-vibration called a bush. And a rubber molded product 12. The size of the small microphone assembly is 6-1
0 mm, height 2-5 mm. Rubber molded product for vibration isolation 1
2 is about 0.9 mm thick. The thickness of the thin metal wire oriented anisotropic conductive rubber connector 13 is about 1.0 mm.

As can be seen from FIG. 1C (bottom view), the sheet of the disc-shaped rubber connector 13 on the electrode surface side has metal on two concentrically arranged electrodes of the small condenser microphone body 11. It is buried and arranged so that the thin line 14 just hits it.

As the metal wire oriented type anisotropic conductive rubber connector 13 used in the above embodiment, specifically, for example,
An anisotropic conductive rubber connector "Fuji Poly Connector W Series" (manufactured by Fuji Kogaku Kogyo Co., Ltd.) in which a thin metal wire made of stainless steel with gold plating all over is oriented in the thickness direction of the silicone rubber sheet, can be used. . The anisotropic conductive rubber connector 13 has a thickness of about 1 to 2 mm, a diameter of the thin metal wire of about 0.010 to 0.030 mm, and a high density portion of the thin metal wire having a density of 5 to 30 mm. Book/
mm ² is preferred.

Further, as a rubber molded product for vibration isolation called a bush, for example, a metal thin wire oriented anisotropic conductive material which covers all the parts other than the electrode surface and the sound collecting part of the small microphone body in a gas-tight manner and is in surface contact with the electrode. A silicone rubber molded product “Fujipoly M Mold 4EC Bush” (manufactured by Fuji Polymer Co., Ltd.) having a shape capable of simultaneously holding and fixing the conductive rubber connector can also be used.

After the vibration-proof rubber molded product 12 is mounted on the small microphone main body 11, the rubber connector 13 is fitted into the rubber molded product 12 on the electrode surface side of the small microphone main body. Thus, the rubber connector is sandwiched and fixed by the elastic force of the rubber molded product for vibration isolation in a state of being in surface contact with the electrode portion of the small microphone body. Thus, a small microphone assembly in which the small microphone body, the rubber molded product for vibration isolation, and the rubber connector are integrated is obtained.

In order to mount the small microphone assembly, the mounting operation is simply performed by assembling the metal wire oriented type anisotropic conductive rubber connector into the main body of the small communication device so as to be in pressure contact with the electrode portion on the circuit board. Once completed, work efficiency in the assembly operation can be greatly improved, mounting space is minimized, and highly reliable electrical connections are possible.

As the rubber material of the above-described metal thin wire oriented anisotropic conductive rubber connector, polybutadiene, natural rubber, polyisoprene, SBR, NBR, EPDM, EP
M, polyurethane polyester rubber, chloroprene rubber, epichlorohydrin rubber, and silicone rubber. Of these, silicone rubber is most preferable in terms of electrical insulation and weather resistance.

The fine metal wires of the anisotropic conductive rubber connector of the fine metal wire orientation type include fine wires of stainless steel, copper, nickel, iron, solder, aluminum, zinc and the like.
Examples include those in which a noble metal such as silver or copper is plated on the entire surface, and those in which a fine wire of stainless steel or nickel is plated with gold on the entire surface are preferable.

[0028]

According to the small microphone assembly using the thin metal wire oriented anisotropic conductive rubber connector of the present invention, the thin metal wire oriented anisotropic conductive rubber connector is connected to the electrode surface of the small microphone body and the small communication device. Highly reliable electrical connection can be made simply by lightly compressing the surface with the electrode surface on the circuit board inside the main body.
Conductive only in the thickness direction of the rubber connector, has anisotropic anisotropic conductivity in the lateral direction, and has a highly reliable electrical connection because metal wires are embedded only on the electrode surface, In addition, since there is no need for complicated rubber connector alignment and multiple circuits can be connected with a single rubber connector, circuit connection for soldering lead wires is not required, and not only can mounting space be reduced. In addition, troublesome mounting work can be omitted.

In addition, a rubber molded product called a bush, which is used for vibration isolation, air-tightly covers all parts other than the electrode surface and the sound collecting part of the small microphone body, and furthermore, a thin metal wire oriented anisotropic conductive rubber connector which is in surface contact with the electrode. Since it has a shape that can be pinched and fixed at the same time, it is possible to integrate the small microphone body and the metal thin wire oriented anisotropic conductive rubber connector. Just assembling the used small microphone assembly at a predetermined location in the small communication device, the small microphone can be mounted,
The work efficiency in the assembly work can be greatly improved.

In addition, by using a rubber molded product for vibration isolation called a bush, not only the vibration isolation reliability of the small microphone main body, but also in a small communication device in which the small microphone assembly is incorporated. Since the surface pressure between the microphone electrode surface and the circuit board electrode surface is fixed at a constant pressure by the rubber elasticity of the bush, a synergistic effect that a highly reliable electrical connection can be achieved is exhibited.

[Brief description of the drawings]

1A is a plan view of a small microphone assembly according to an embodiment of the present invention, FIG. 1B is a cross-sectional view taken along line II of FIG. 1A, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Small microphone assembly 11 Small capacitor / microphone main body 12 Rubber molded product for vibration isolation 13 Fine metal wire oriented anisotropic conductive rubber connector 14 Fine metal wire

Claims (12)

[Claims] 1. A small-sized microphone body is covered with a vibration-proof rubber molded product, and an anisotropic conductive rubber connector having a thin metal wire orientation is sandwiched and fixed so as to make surface contact with an electrode portion of the small-sized microphone body. A small microphone assembly comprising a microphone body, a rubber molded product for vibration isolation covering the microphone body, and a thin metal wire oriented anisotropic conductive rubber connector. 2. The small microphone assembly according to claim 1, wherein the rubber molded product for vibration isolation is made of silicone rubber. 3. The small microphone assembly according to claim 1, wherein the thin metal wires included in the thin metal wire-oriented anisotropic conductive rubber connector are oriented so as to penetrate in the thickness direction of the rubber connector. 4. The small microphone assembly according to claim 1, wherein the thin metal wire included in the thin metal wire oriented anisotropic conductive rubber connector is embedded so as to match the shape of the electrode portion of the small microphone body. 5. The small microphone assembly according to claim 1, wherein the rubber portion of the thin metal wire oriented anisotropic conductive rubber connector is made of silicone rubber. 6. The small microphone assembly according to claim 1, wherein the thin metal wire included in the thin metal wire-oriented anisotropic conductive rubber connector is a thin metal wire whose entire surface is treated with a noble metal plating. 7. The diameter of a thin metal wire included in a thin metal wire oriented type anisotropic conductive rubber connector is 0.010 to 0.030 m.
The small microphone assembly according to claim 1, wherein m is m. 8. The small microphone assembly according to claim 1, wherein the burying density of the fine metal wires included in the fine metal wire oriented anisotropic conductive rubber connector is 5 to 30 wires / mm ² at the highest density portion. . 9. The small microphone assembly according to claim 1, wherein the thin metal wire-oriented anisotropic conductive rubber connector has compressive elasticity and can be assembled by being brought into surface contact with an electrode portion on a circuit board. 10. The small microphone assembly according to claim 1, wherein the compression elasticity of the rubber portion of the thin metal wire oriented anisotropic conductive rubber connector is in the range of 20 to 70 according to the method A of JIS K6301. 11. The small microphone assembly according to claim 1, wherein the small microphone assembly is a small microphone assembly incorporated in a main body of a small portable communication device. 12. The small microphone assembly according to claim 11, wherein the small portable communication device is a mobile phone.