CN2854993Y

CN2854993Y - Mini-electret microphone

Info

Publication number: CN2854993Y
Application number: CN 200520144034
Authority: CN
Inventors: 王显彬; 王玉良
Original assignee: Weifang Goertek Electronics Co Ltd
Current assignee: Goertek Inc
Priority date: 2005-12-14
Filing date: 2005-12-14
Publication date: 2007-01-03
Anticipated expiration: 2015-12-14

Abstract

The utility model relates to a condenser microphone which is an embodiment of a microelectret microphone. The condenser microphone includes a dustproof net, a shell, a circuit board, a cylindraceous cavum consisted of the shell and the circuit board, a sound bore backplate mounted in the cavum, a spring mounted between the circuit board and the backplate. One end of the spring is connected with the circuit board, and the other end is connected with the backplate. In the utility model, the bar ring is replaced with the spring mounted in the cavum to connecting the circuit. Accordingly, the volume of the inner-cavum is increased, the parasitic capacitance is decreased, the capability of the production is ensured, and simultaneity, the process is predigested, the assembly efficiency is enhanced and the cost is reduced.

Description

A kind of minisize electret microphone

Technical field

The utility model relates to condenser microphone, is a kind of minisize electret microphone specifically.

Background technology

Common electret capcitor microphone, its structure be mainly by Air Filter, shell, wiring board, field effect transistor, electric capacity, grating ring, cavity, back pole plate, pad, vibrating diaphragm compositions such as (ring+film shake) all adopts grating ring to connect back pole plate and wiring board, realizes the connection of circuit.Its operation principle is: when sound acts on the diaphragm, by the vibration of diaphragm, change the distance of the plane-parallel capacitor that forms between diaphragm and the back pole plate, produce a current signal, be delivered to the transmission that wiring board is realized signal by grating ring, reach the purpose of sound one electricity conversion.Current, development along with technology, because pressure of competition, market to the demand of product towards miniaturization, even microminiaturized development, thereby, require more and more littler to small product size, cause electret capcitor microphone manufacturer to reduce the diameter and the height of finished product gradually, cause the decreased performance of electret microphone, reduce as limiting snesibility etc.Present product, because the advantage on portion's volume within it, its inside can take a fairly large number of parts in, as cavity, grating ring, the combination of back pole plate.And along with the development of the miniaturization of products, its diameter reduces gradually, if adopt cavity again, the grating ring structure is come deisgn product, not only increases difficulty aspect the processing of parts, can promote production cost simultaneously, the most important thing is that the grating ring structure takies bigger ratio space in the internal capacity of less electret microphone, cause the microphone inner space to reduce because of cavity, thereby the decreased performance that finally causes electret microphone is as sensitivity reduction of electret microphone etc.For adapting to market miniaturization and microminiaturized demand, the SONION company of Denmark has released a kind of minisize electret microphone, the patent No. is EP 1 251 713 A2, the shortcoming that the space that reduces to bring of volume reduces though its product can be good at solving, but its structure that adopts comes with some shortcomings, as its complex-shaped back pole plate, mainly bear the effect of a utmost point of plane-parallel capacitor, also bear the effect of connecting circuit simultaneously, its material has been selected plastic raw materials, compare with metal, its intensity obviously reduces, and unfailing performance reduces.Secondly, in assembling process, in order to realize the connection of circuit, back pole plate needs accurate localization, perhaps is coated with the method for conductive adhesive, just can accurate firm being connected with the contact point on the wiring board.So both cause the reduction of efficiency of assembling, and can increase production cost again.

Summary of the invention

The purpose of this utility model is intended in order to overcome the deficiency that above-mentioned technology exists, a kind of structure of new electret capcitor microphone is provided, substitute cavity grating ring structure, effectively solve the shortcoming that properties of product that electret microphone causes owing to the inner space diminishes descend, both reached and to realize the circuit purpose of connecting, can keep the purpose of the stable performance of electret capcitor microphone again.

For achieving the above object, the utility model adopts following technical scheme:

A kind of minisize electret microphone described in the utility model comprises Air Filter, shell, wiring board, be fixedly connected with field effect transistor and electric capacity on the wiring board, wiring board is fixedlyed connected with shell, Air Filter covers on the sound hole of shell, have cavity cylindraceous in the cavity that shell and wiring board constitute, the back pole plate in the sound hole of mounting strap in the cavity is equipped with spring between wiring board and back pole plate, one end of spring is electrically connected with wiring board, and the other end is electrically connected with back pole plate.

Above-mentioned described spring can be a helical spring, also can be elastic metallic yarn.

For ease of installing, the end welding of spring in the circuit board.

After adopting technique scheme, characteristics such as the utlity model has that assembly technology is simple, cost is low, good product performance, stability are strong, owing to adopted the cavity body structure of compact conformation, the volume of inner chamber that effectively solved increase relative on the basis that small product size reduces, guaranteed the stable of properties of product, simplify assembly technology simultaneously, improved efficiency of assembling, reduced production cost again.

Description of drawings

Fig. 1 is existing small-sized electret capcitor microphone structure chart;

Fig. 2 is the structural representation of an embodiment of the present utility model;

Fig. 3 is the structural representation of another embodiment of the present utility model;

Embodiment

As shown in Figure 2, miniature electret capacitor microphone described in the utility model comprises Air Filter 1, shell 2, wiring board 3, be fixedly connected with field effect transistor 4 and electric capacity 5 on the wiring board 3, wiring board 3 is fixedlyed connected with shell 2, Air Filter 1 covers on the sound hole of shell 2, have cavity 7 cylindraceous in the cavity that shell 2 and wiring board 3 constitute, between the lower end of cavity 7 and the shell 2 vibrating diaphragm 10 is installed.The back pole plate 8 in the sound hole of mounting strap in the cavity 7 is equipped with spring 6 between wiring board 3 and back pole plate 8, an end of spring 6 is welded on the wiring board 3, and the other end is electrically connected with back pole plate 8.As shown in Figure 3, spring 6 can be a helical spring, also can adopt elastic wire to replace.For the ease of installing and reducing production costs, in advance spring 6 is welded on the wiring board 3, and makes the length of spring 6 be slightly larger than the inner chamber degree of depth of cavity 7.When wiring board 3 was installed on the shell 2, the other end of spring 6 was against on the back pole plate 8 and relies on the elasticity of spring to realize being electrically connected with back pole plate 8.

When voice signal sees through Air Filter 1, when acting on the vibrating diaphragm 10, diaphragm 10 produces vibration with signal, the vibrating diaphragm 10 and the distance of the capacitor of back pole plate 8 formation are changed, produce the current signal of a variation thereupon, by the spring 6 that is positioned at cavity, be delivered to the input of the field effect transistor 4 on the wiring board 3, thus the process of realization sound one electricity conversion.

The utility model adopts the spring be positioned at inside cavity to substitute grating ring to come connecting circuit, increased the volume of inner chamber, reduce parasitic capacitance, guaranteed the performance of product, simplified technological process simultaneously, efficiency of assembling is provided, reduced cost.

Claims

1, a kind of minisize electret microphone, comprise Air Filter (1), shell (2), wiring board (3), be fixedly connected with field effect transistor (4) and electric capacity (5) on the wiring board (3), wiring board (3) is fixedlyed connected with shell (2), Air Filter (1) covers on the sound hole of shell (2), have cavity cylindraceous (7) in the cavity that shell (2) and wiring board (3) constitute, the back pole plate (8) in the sound hole of mounting strap in the cavity (7), it is characterized in that: between wiring board (3) and back pole plate (8), spring (6) is installed, one end of spring (6) is electrically connected with wiring board (3), and the other end is electrically connected with back pole plate (8).

2, a kind of minisize electret microphone according to claim 1 is characterized in that: described spring (6) is a helical spring.

3, a kind of minisize electret microphone according to claim 1 is characterized in that: described spring (6) is an elastic metallic yarn.

4, according to claim 1 or 2 or 3 described a kind of minisize electret microphones, it is characterized in that: an end of described spring (6) is welded on the wiring board (3).