Silica-based condenser microphone
[technical field]
The utility model relates to a kind of microphone, relates in particular to a kind of silica-based condenser microphone.
[background technology]
Development along with wireless telecommunications, Global Mobile Phone Users is more and more, the user not only is satisfied with conversation to the requirement of mobile phone, and want high-quality communication effect can be provided, especially at present the development of mobile multimedia technology, the speech quality of mobile phone becomes more important, and the microphone of mobile phone is as the voice pick device of mobile phone, and its design quality directly influences speech quality.
And the microphone of using more and better performances at present is a silica-based condenser microphone.As shown in Figure 1, the silica-based condenser microphone 100 ' of correlation technique comprises: circuit board 14 ', be covered in the loam cake 20 ' of circuit board 14 ', the cavity 15 ' that forms jointly by circuit board 14 ' and loam cake 20 ' and be contained in the cavity 15 ' and place transducer 12 ' and control circuit 16 ' on the circuit board 14 ' respectively, wherein loam cake 20 ' is provided with sound hole 21 '.
The silica-based condenser microphone 100 ' of correlation technique, sound directly enters cavity 15 ' from sound hole 21 ', make transducer 12 ' and control circuit 16 ' in the cavity 15 ' be directly exposed under the sound hole 21 ', can bring particles such as similar dust into, stability that will influence silica-based condenser microphone 100 ' and reliability of a specified duration.
In addition, in drop test, find, if sound hole 21 ' diameter is excessive, in falling process, can influence the life-span of transducer 12 ', so it is little that the diameter of customer requirement sound hole 21 ' will be tried one's best, yet, at present can't be from designing the diameter that dwindle sound hole 21 '.
Therefore, be necessary to provide a kind of new silica-based condenser microphone to overcome above-mentioned defective.
[utility model content]
The technical problems to be solved in the utility model is to provide a kind of stable performance, silica-based condenser microphone that reliability is high.
The utility model solves above-mentioned technical problem by such technical scheme:
A kind of silica-based condenser microphone, it comprises: circuit board, be covered in the loam cake with host cavity of circuit board and place transducer and control circuit on the circuit board respectively, wherein, be covered with on upper surface and with the upper surface opposing lower surface, extend and do not pass first tone-entering hole of lower surface to lower surface from the upper surface of loam cake, from the lower surface of loam cake to upper surface extend but do not pass upper surface and with first tone-entering hole, second tone-entering hole laterally separated by a distance and be located at the upper surface of loam cake and lower surface between be connected first simultaneously, the interface channel of second tone-entering hole.
Preferably, described loam cake is a three-decker, it comprise ground floor, the second layer and be clipped in ground floor and the second layer between the intermediate layer, described first tone-entering hole runs through this ground floor, second tone-entering hole runs through this second layer, interface channel is located at the intermediate layer.
Preferably, the sidewall that is covered with diapire on described and extends from diapire, described first, second tone-entering hole and interface channel are located on the diapire of loam cake.
Compared with prior art, the utlity model has following advantage: on cover the setting of interface channel, make outer boundry particle can't directly enter the cavity of silica-based condenser microphone, play certain dustproof effect.In addition, silica-based condenser microphone of the present utility model has objectively reduced the area of sound hole, has increased product stability.
[description of drawings]
Fig. 1 is the cross-sectional schematic of correlation technique silica-based condenser microphone.
Fig. 2 is the cross-sectional schematic of the utility model silica-based condenser microphone.
[embodiment]
Describe concrete structure of the present utility model in detail below in conjunction with accompanying drawing.
The utility model silica-based condenser microphone 100 can be used on the mobile phone, receives acoustical signal and acoustical signal is converted into the signal of telecommunication.
Please join shown in Figure 2ly, the utility model silica-based condenser microphone 100 mainly comprises circuit board 1, is covered in the loam cake 2 of circuit board 1 and places transducer 3 and control circuit 4 on the circuit board 1 respectively.
The sidewall 22 that loam cake 2 is provided with diapire 21, extend from diapire 21, the cavitys 23 that form jointly by diapire 21 and sidewall 22, wherein, the diapire 21 of loam cake 2 be provided with upper surface 211 and with upper surface 211 opposing lower surface 212.Extend and do not pass lower surface 212 to lower surface 212 from the upper surface 211 of loam cake 2 and be provided with first tone-entering hole 24; From the lower surface 212 of loam cake 2 to upper surface 211 extend but do not pass upper surface 211 and with first tone-entering hole, 24 horizontal second tone-entering holes 25 that are provided with separated by a distance; Between the upper surface 211 of loam cake 2 and lower surface 212, connect first, second tone-entering hole 24,25 simultaneously and be provided with interface channel 26.Described first, second tone-entering hole 24,25 and the interface channel 26 common sound holes (not label) that form silica-based condenser microphone 100.
The diapire 21 of described loam cake 2 is a three-decker, it comprises ground floor 213, the second layer 214 and is clipped between the ground floor 213 and the second layer 214 intermediate layer 215, described first tone-entering hole 24 runs through these ground floor 213, the second tone-entering holes 25 and runs through this second layer 214, and interface channel 26 is located at intermediate layer 215.
The setting of interface channel 26 on the loam cake 2 makes outer boundry particle can't directly enter the cavity 23 of silica-based condenser microphone 100, plays certain dustproof effect.In addition, silica-based condenser microphone 100 of the present utility model has objectively reduced the area of sound hole, has increased product stability.
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.