CN201491263U

CN201491263U - Electret microphone

Info

Publication number: CN201491263U
Application number: CN2009201336917U
Authority: CN
Inventors: 方涛
Original assignee: AAC Acoustic Technologies Shenzhen Co Ltd; AAC Acoustic Technologies Changzhou Co Ltd
Current assignee: AAC Technologies Holdings Shenzhen Co Ltd; AAC Technologies Holdings Changzhou Co Ltd; AAC Technologies Holdings Inc
Priority date: 2009-07-17
Filing date: 2009-07-17
Publication date: 2010-05-26
Anticipated expiration: 2019-07-17

Abstract

An electret microphone comprises a shell, a membrane combination contained in the shell, a spacer arranged on the membrane combination, a back pole plate adjoining the spacer and a circuit board electrically connected with the shell, wherein the back pole plate is provided with a metal layer and an electret layer connected with the metal layer; the metal layer comprises a bottom surface and a side wall that extends from the bottom surface and can be connected against the circuit board; and the electret layer is connected with one side on the bottom surface of the metal layer, close to the spacer. The electret microphone has few parts, omits certain assembly procedures and greatly improves the working efficiency. In addition, compared with the electret microphone of relevant technologies, the area of the electret layer on the back pole plate is increased and can improve the sensitivity of the electret microphone.

Description

Electret microphone

[technical field]

The utility model relates to a kind of microphone, relates in particular to a kind of electret microphone.

[background technology]

Mobile communication technology is rapidly developed in recent years.The consumer uses mobile communication equipment more and more, and for example portable phone, the portable phone that can surf the Net, personal digital assistant, laptop computer, laptop computer, figure input card maybe can be by other equipment public or that dedicated communications network communicates.The technological progress of the expansion at honeycomb networking and mobile communication aspect makes more consumers use mobile communication equipment.The growing demand of communication equipment has been promoted to be integrated in the improvement of manufacturing process, power consumption, reception, manufacturing and the miniaturization aspect of the audio components in the mobile communication equipment.Competitive pressure between the supplier of mobile communication equipment has increased demand littler, more cheap and the electret microphone that performance is more excellent.

Fig. 1 is a kind of three-dimensional exploded view of the electret microphone 80 ' relevant with the utility model, and this electret microphone 80 ' comprises shell 81 ', be connected membrane combination 82 ' with shell 81 ', place pad 83 ' on the membrane combination 82 ', place back-pole base 85 ' on the pad 83 ', be contained in back pole plate 84 ' in the back-pole base 85 ' and connecting ring 86 ' and lid is connected to circuit board 87 ' on the shell 81 '.

Yet the electret microphone 80 ' parts of dependency structure are more, the assembling procedure complexity.

Therefore, be necessary to provide a kind of new electret microphone to overcome above-mentioned shortcoming.

[utility model content]

The purpose of this utility model is to provide a kind of electret microphone simple in structure.

The purpose of this utility model is achieved in that a kind of electret microphone, it comprises shell, be contained in membrane combination in the shell, be positioned over pad on the membrane combination, with the back pole plate of pad adjacency and the circuit board that electrically connects with shell, wherein, described back pole plate is provided with metal level and the electret layer that links to each other with metal level, metal level comprise the bottom surface and the be connected to circuit board that extends from the bottom surface on sidewall, the side near pad on the bottom surface of described electret layer and metal level links to each other.

Preferably, described Mike phoenix also be provided with extend from electret layer and covering insulating barrier on the sidewall of metal level.

Compared with prior art, the utlity model has following advantage: electret microphone amount of parts of the present utility model is few, has saved some assembling procedures, has improved operating efficiency greatly.In addition, the electret microphone with correlation technique compares the area of electret layer increase on the back pole plate, the sensitivity that can improve electret microphone.

[description of drawings]

Fig. 1 is the three-dimensional exploded view of the electret microphone relevant with the utility model.

Fig. 2 is the three-dimensional exploded view of the utility model electret microphone.

Fig. 3 is the cutaway view of back pole plate in the utility model electret microphone.

Fig. 4 is the cutaway view of the utility model electret microphone.

[embodiment]

Please join Fig. 2-shown in Figure 4, the utility model electret microphone 100, it comprise shell 1, lid be connected to circuit board 7 on the shell 1, be contained in membrane combination 2 in the shell 1, be positioned on the membrane combination 2 pad 3 and with the back pole plate 4 of pad 3 adjacency.

Shell 1 comprises square roof 11 and four side walls 12 that extend from roof 11, wherein, offer on the roof 11 in order to accept first tone-entering hole 13 of outside sound source, so that sound wave can be sent to membrane combination 2, this first tone-entering hole 13 can form by any suitable mode (for example boring, punching or molded).Be to guarantee the encapsulation of electret microphone 100 integral body, also bend to extend internally in the end of side wall 12 and be held in holding part 14 on the circuit board 7.In addition, in different execution modes, shell 1 can have different shapes.

Though the shape of membrane combination 2 is corresponding with the shape of shell 1 in the present embodiment, in different execution modes, can adopt multiple shape, membrane combination 2 that size is different.

Pad 3 comprises outer shroud 31 and the centre bore 32 that is centered on by outer shroud 31.This pad 3 is used to make membrane combination 2 and other element electricity in the shell 1 to isolate.Pad 3 is made by electrical insulating material, has the thickness of spacing between membrane combination of equaling 2 and the back pole plate 4.Pad 3 makes that membrane combination 2 can be towards back pole plate 4 distortion.Pad 3 can have multiple shape, and needn't be corresponding with shell 1 shape, and can have multiple different size.In the present embodiment, pad 3 is and shell 1 corresponding square configuration.

Back pole plate 4 is provided with metal level 41, the electret layer 42 that links to each other with metal level 41 and runs through metal level 41 simultaneously and second tone-entering hole 44 of electret layer 42.Wherein, metal level 41 comprises bottom surface 411 and the sidewall 412 on the be connected to circuit board of bottom surface 411 extensions, and described electret layer 42 links to each other with a side of the bottom surface 411 close pads 3 of metal level 41.Described back pole plate 4 also is provided with from covering in the insulating barrier 43 of the sidewall 412 of metal level 41 that electret layer 42 extends, and this insulating barrier 43 and electret layer 42 are one.

Have electret on the electret layer 42, electret is a kind of dielectric that can keep the electric polarization state for a long time, and this dielectric is a kind of high molecular polymer, is distributed with free charge on the electret.Owing to be distributed with free charge on the electret, so between the two poles of the earth of the capacitor that forms between vibrating diaphragm group 2 and the back pole plate 4, the quantity of electric charge has just been arranged, when sound wave makes vibrating diaphragm group 2 vibration and when producing displacement, changed the capacitance of capacitor, the change of capacitance makes the output of capacitor produce corresponding alternating electric field, just formed the signal of telecommunication corresponding, so just finished the function of acoustic-electric conversion with acoustic signals.

Described making electret layer 42 with the method for insulating barrier 43 is:

Step 1 a: polymer material film is provided;

Step 2: the middle part to polymer material film applies high voltage, makes its middle part form electret layer 42, and then its both sides form insulating barrier 43.

The matching relationship of above-mentioned each element is as follows:

Back pole plate 4 electrically connects by metal level 41 and circuit board 7; Pad 3 is between back pole plate 4 and membrane combination 2, in order to form the gap between back pole plate 1 and membrane combination 2; Membrane combination 2 is placed on the pad 3, and is housed in the shell 1, and membrane combination 2 electrically conducts with shell 1; Shell 1 is electrically connected on the corresponding circuits of circuit board 7.Such matching relationship, make membrane combination 2 be electrically connected to circuit board 7, back pole plate 4 also is electrically connected to circuit board 7, and still two circuit are because of directly conducting of the gap that forms between back pole plate 4 and the membrane combination 2, and back pole plate 4 has just formed capacitance body with membrane combination 2.

Electret microphone amount of parts of the present utility model is few, has saved some assembling procedures, has improved operating efficiency greatly.In addition, the electret microphone with correlation technique compares the area of electret layer increase on the back pole plate, the sensitivity that can improve electret microphone.

The above only is a better embodiment of the present utility model; protection range of the present utility model does not exceed with above-mentioned execution mode; as long as the equivalence that those of ordinary skills do according to the utility model institute disclosure is modified or changed, all should include in the protection range of putting down in writing in claims.

Claims

1. electret microphone, it comprises shell, be contained in membrane combination in the shell, be positioned over pad on the membrane combination, with the back pole plate of pad adjacency and the circuit board that electrically connects with shell, it is characterized in that: described back pole plate is provided with metal level and the electret layer that links to each other with metal level, wherein, metal level comprise the bottom surface and the be connected to circuit board that extends from the bottom surface on sidewall, the side near pad on the bottom surface of described electret layer and metal level links to each other.

2. electret microphone according to claim 1 is characterized in that: described Mike phoenix also be provided with extend from electret layer and covering insulating barrier on the sidewall of metal level.