KR100632694B1 - Electret condenser microphone - Google Patents

Abstract

An electric condenser microphone is provided to improve the temperature characteristic by having an insulation base surrounding a pair of vibration plates and a rear electrode plate. A case(102) includes concaves(102a). An insulation base(110) is mounted in the bottom of the case(102) to insulate the case(102) with an inner component. A vibration plate(104) is mounted in the insulation base(110), is connected to the bottom of the case(102) electrically and vibrates according to a sound pressure inputted through the concaves(102a). A spacer(106) is mounted in the insulation base(110) to form a gap between the vibration plate(104) and a rear electrode plate(108). The rear electrode plate(108) is mounted in the insulation base(110), faces the vibration plate(104) and is configured to press an organic film(108b) to a metal plate(108a) to form an electret. A conductive base(112) has a cylinder shaped body which has two open ends and a supporting unit which has a wide supporting area because the top of cylinder shaped body is protruded to the outside, to conduct the rear electrode plate(108) and to support a PCB(114) at the curling process. The PCB(114) is supported by the conductive base(112), forms a back chamber together with the rear electrode plate(108) and includes components. The conductive base(112) supports the PCB(114) when curling the end of the case(102), after inserting the components into the case(102).

Description

Electret condenser microphone {ELECTRET CONDENSER MICROPHONE}

1 is a side cross-sectional view of a conventional condenser microphone assembly,

2 is a diagram illustrating the concept of the present invention;

3 is a cross-sectional view showing a conductive base of a condenser microphone applied to the present invention;

4 is a side cross-sectional view of a condenser microphone assembly according to the present invention;

5 is a side cross-sectional view of a condenser microphone assembly having a protruding terminal according to the present invention;

6 is an external view of the condenser microphone assembly shown in FIG. 5;

7 is a side cross-sectional view of another embodiment according to the present invention;

8 is an assembly flowchart of a condenser microphone according to the present invention;

* Explanation of symbols for main parts of the drawings

102: case 104: diaphragm

104a: polaring 104b: conductive film

106: spacer 108: back electret

110: insulated base 112: conductive base

112a: body 112b: support portion

114: PCB 114a, b: connection terminal

100,100 ': electret condenser microphone

The present invention relates to an electret condenser microphone, and more particularly, to an electret condenser microphone which can prevent deformation of parts during curling and improve high temperature characteristics.

A typical condenser microphone has a voltage bias element (usually an electret), a diaphragm / backplate pair that forms a capacitor (C) that changes in response to sound pressure, and a field effect to buffer the output signal. It consists of a transistor (JFET). Here, in the electret condenser microphone, an electret is formed on any one of the vibration membrane and the back plate, and the electret is formed on the vibration membrane, and the electret is formed on the back plate. Typically, electrets are formed by forcing charges into an organic film.

1 is a side cross-sectional view of a condenser microphone assembly using a conventional case. In the conventional microphone assembly, a sound hole 10c is formed in the bottom surface of the case 10, and the vibration membrane 12a and the inside of the case 10 are formed. After inserting the diaphragm 12 made of the polar ring 12b, the spacer 13, the insulating base 14, the back plate 15, and the conductive base 16, the PCB 18 is finally mounted to mount the case. It has a structure in which the end 10b is curled.

At this time, the conductive base 16 not only transmits an electric signal from the microphone unit (vibration plate / back electret) to a JFET or an element including an amplifier or an amplifier and an AD converter, but also mechanically inserts an inserted internal component. It plays a role of fixing.

When the conductive base 16 is curled higher than the insulating base 14, the PCB 18 presses the conductive base 16.

However, such a conventional microphone has a weak bearing force by the base in the PCB 18 in a curling process in which the end of the case 10 is pressed while pressing the end of the case 10 to the PCB 18, or according to the tolerance of the component. There is a problem that the PCB 18 is bent or the internal parts are deformed, which adversely affects the acoustic characteristics.

The present invention has been proposed to solve the above problems, the insulating base is wrapped around the diaphragm and the bipolar plate pair to improve the temperature characteristics, when the case of the curling (curling) of the "a" shaped conductive base having a wide support surface It is an object of the present invention to provide an electret condenser microphone which supports a PCB to prevent deformation of the component.

In order to achieve the above object, the electret condenser microphone of the present invention includes a case in which sound holes are formed on a bottom surface thereof; An insulation base having an insulation function for electrically insulating the case and the internal parts and mounted to contact the bottom surface of the case; A vibration plate mounted in the insulating base and electrically connected to the bottom surface of the case and vibrating according to the sound pressure input through the sound hole; A spacer mounted in the insulating base to form a gap; A bipolar plate mounted in the insulating base and facing the diaphragm and the spacer therebetween, and having a polymer film adhered to the outside of the metal plate to form an electret; A conductive base having a cylindrical body having both sides open and a support portion having an upper surface of the body protruded outward to support a wider support area, while conducting the bipolar plate and supporting the PCB when curling; And a back chamber supported by the conductive base to form a back chamber therein, wherein the conductive base includes a PCB in which circuit components are mounted, and then inserting the components into the case and curling the end of the case. Characterized in that it is to support the PCB.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view illustrating the concept of the present invention, an enlarged view in a first circle is a conceptual diagram showing a concept of bending the PCB 18 when curling in a conventional condenser microphone, and an enlarged view in a second circle is shown in the present invention. When curling in the microphone according to the "a" shaped conductive base 112 supports the PCB 114 is a conceptual diagram showing a concept of preventing the bending of the PCB 114.

Referring to FIG. 2, since the conductive base 16 supporting the PCB 18 is conventionally shaped as shown in the enlarged view of the first circle, the area supporting the PCB 18 is narrow so that the end 10b of the case is folded. When bending to the PCB 18 side, the end and the inner side of the PCB 18 is bent inward by the pressure when curling, and thus the sound path is changed to degrade the sound quality or to damage the components mounted on the PCB. . However, according to the present invention, as shown in the enlarged view in the second circle, the upper support surface that meets the PCB 114 surface at the conductive base 112 protrudes outwards in an "a" shape to curl the end 102b of the case when the PCB ( By broadly supporting the surface 114, the bending of the PCB 114 can be prevented.

3 is a cross-sectional view showing a conductive base of a condenser microphone according to the present invention.

As shown in FIG. 3, the conductive base 112 applied to the present invention has a cylindrical body 112a having both sides open, and an upper surface of the body 112a protruding outward to support the PCB 114. It consists of the support part 112b by which the flat area was widened, and the left end surface becomes "┐" shape, and the right end surface is "┌" improvement. As described above, in the conductive base 112 according to the present invention, the support part 112b supporting the surface of the PCB 114 is wider than the body 112a so that the support area during curling is increased to prevent the PCB 114 from bending. .

4 is a side cross-sectional view of an electret condenser microphone assembly in accordance with the present invention.

As shown in FIG. 4, the condenser microphone 100 assembled using the conductive base 112 of the present invention is insulated from the cylindrical case 102 in which one surface is opened and the sound hole 102a is formed on the bottom surface. A spacer for forming a gap with the diaphragm 104 serving as a movable electrode, comprising an insulating base 110 functioning as a polar ring 104a and a diaphragm 104b in the insulating base 110. 106 and the sound hole 108a and the conductive base 112 providing the conductive function for the bipolar plate 108 and the bipolar plate 108, which serve as a fixed electrode, are sequentially inserted. The mounted PCB 114 is inserted and the end 102b of the case is curled. At this time, the organic film 108b is pressed onto the metal plate 108a, and the electrode plate 108 has a form in which electrets are formed by forcibly injecting electric charges into the organic film 108b.

Referring to FIG. 4, the insulating base 110 of the present invention is installed to reach the bottom surface of the case 102 longer than the conventional insulating base, and the diaphragm (the spacer 106 is interposed therebetween) in the insulating base 110. 104 is a structure in which the bipolar plate 108 is opposed to each other. As described above, in the electret condenser microphone 100 of the present invention, since the insulating base 110 surrounds the diaphragm 104 and the back electret, the internal electret may be protected during high temperature reflow for surface mount (SMT). Can be. The material of the insulating base 110 is preferably made of a fluorine resin-based, polymer-based, or plastic-based material having heat resistance and chemical resistance.

5 is a side cross-sectional view of a condenser microphone assembly having a protruding terminal according to the present invention. In the structure as shown in FIG. 4, a connection terminal 114a protruding higher than the curing surface 102b of the case on the exposed surface of the PCB 114 is shown. 114b) is formed.

Referring to FIG. 5, the exposed surface of the PCB 114 is formed such that the connection terminals 114a and 114b protrude from the curing surface 102b of the case 102 such that the microphone 100 has another PCB (eg, a PCB of a mobile phone). ) It can be attached by SMD method. As shown in FIG. 6, the connection terminals 114a and 114b for this purpose are formed with a circular terminal 114a for a Vdd connection on the inside, and a circular ground terminal 114b on the outside with a predetermined interval. have. Although not shown in the drawing, the ground terminal 114b may be separated by a gas discharge groove so as to discharge the gas generated when the SMD is adhered according to need.

In the condenser microphone 100 of the present invention as described above, when air is introduced into the microphone through the sound hole 102a of the case 102 by external sound waves, the vibration membrane 104b is vibrated by the sound pressure and the double plate Through the through hole (108a) formed in the 108 is introduced into the back chamber formed between the PCB 114 and the bipolar plate 108. At this time, when the vibrating membrane 104b vibrates due to the sound pressure introduced through the sound hole 102a, the distance between the vibrating membrane 104b and the bipolar plate 108 is changed. When the interval is changed by the sound pressure, the capacitance formed by the vibrating membrane 104b and the bipolar plate 108 is changed to obtain a change in the electrical signal (voltage) according to the sound wave. It is transferred to ICs such as JFETs mounted on the amplified circuit board and amplified, and then transmitted to the outside through a connection terminal (not shown).

FIG. 7 is a side cross-sectional view of another embodiment according to the present invention, where the position of the diaphragm 104 and the bipolar plate 108 in the insulating base 110 is compared with the structure shown in FIG. 4 with the spacer 106 interposed therebetween. It can be seen that the structure has changed 180 degrees.

Referring to FIG. 7, the insulating base 110 of the present invention is longer than the conventional insulating base and is installed to contact the bottom surface of the case. The insulating base 108 and the diaphragm (with the spacer 106 interposed therebetween) are provided in the insulating base. 104 is a structure facing each other.

As described above, in the electret condenser microphone 100 ′ of the present invention, since the insulating base 110 surrounds the electret, an internal electret may be protected during high temperature reflow for surface mount (SMT). The material of the insulating base is preferably made of a fluororesin-based, polymer-based, or plastic-based material having heat resistance and chemical resistance.

8 is an assembly flowchart of a condenser microphone according to the present invention.

Referring to FIG. 8, the assembling procedure of the microphone according to the present invention includes preparing a case 102 (S1), inserting an insulating base 110 into the case 102 (S2), and a first structure ( In the case of FIG. 4, the diaphragm 104, the spacer 106, and the bipolar plate 108 are sequentially inserted into the insulating base 110 (S3 to S5), and the second structure (FIG. 7) is inserted into the insulating base 110. Inserting the bipolar plate 108, the spacer 106, and the diaphragm 104 sequentially (S6 to S8), inserting the T-type metal base (conductive base 112) (S9), and inserting the PCB 114. It consists of a step (S10), the step of curling (S11).

As described above, the electret condenser microphone according to the present invention broadly supports the PCB in a part where the conductive base having a wide support surface is curled in a "c" shape in the curling process of the case end, thereby causing the PCB to bend or otherwise. It is possible to provide a microphone with good acoustic characteristics by applying stress to the component to prevent the component from being deformed.

In addition, the electret condenser microphone of the present invention can prevent the insulator base from deteriorating the electret characteristics during high temperature reflow by enclosing the diaphragm and the bipolar plate pair.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (4)

A case in which sound holes are formed on the bottom surface; An insulation base having an insulation function for electrically insulating the case and the internal parts and mounted to contact the bottom surface of the case; A vibration plate mounted in the insulating base and electrically connected to the bottom surface of the case and vibrating according to the sound pressure input through the sound hole; A spacer mounted in the insulating base to form a gap; A bipolar plate mounted in the insulating base and facing the diaphragm and the spacer therebetween, and having a polymer film adhered to the outside of the metal plate to form an electret; A conductive base having a cylindrical body having both sides open and a support portion having an upper surface of the body protruded outward to support a wider support area, while conducting the bipolar plate and supporting the PCB when curling; And A PCB is supported by the conductive base to form a back chamber therein together with the bipolar plate, and includes a PCB on which circuit components are mounted. And the conductive base supports the PCB when the end of the case is curled after inserting the components into the case. A case in which sound holes are formed on the bottom surface; An insulation base having an insulation function for electrically insulating the case and the internal parts and mounted to contact the bottom surface of the case; A bipolar plate mounted in the insulating base and having a polymer film adhered to an outer side of the metal plate and having an outlet formed therein; A spacer mounted in the insulating base to form a gap; A diaphragm mounted in the insulating base and facing the bipolar plate with the spacer interposed therebetween and vibrating according to the sound pressure input through the sound hole; A conductive base having a cylindrical body having both sides open and a support portion having an upper surface of the body protruded outward to support a wider support area, thereby conducting the diaphragm and supporting the PCB when curling the support portion; And A PCB is supported by the conductive base to form a back chamber therein together with the diaphragm, and includes a PCB mounted with circuit components. And the conductive base supports the PCB when the end of the case is curled after inserting the components into the case. The electret condenser microphone according to claim 1 or 2, wherein the conductive base has a cylindrical shape or a square cylindrical shape. The method of claim 1 or 2, wherein the exposed surface of the PCB An electret condenser microphone, characterized in that a protruding connecting terminal is formed for connecting to an external device.

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