CN201114765Y - electret microphone - Google Patents

Abstract

The utility model relates to an electret microphone, which comprises a shell, a circuit board, a vibrating membrane, a spacer and a back plate. The circuit board base is arranged on the shell, and a through hole is opened at the central position to receive external sound signals. The circuit board is provided with a number of soldering feet protruding from the shell to connect with the circuit of the microphone environment.

Description

electret microphone

【Technical field】

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

【Background technique】

With the development of wireless communication, there are more and more mobile phone users around the world. The requirements of users for mobile phones are not only satisfied with calls, but also to be able to provide high-quality call effects. Especially the current development of mobile multimedia technology, the mobile phone Call quality is more important. The microphone of a mobile phone is used as a voice pick-up device for the mobile phone, and its design directly affects the call quality. In addition, as mobile phones are increasingly miniaturized, how to maintain good performance of the components on them, such as microphones, in a continuously shrinking volume is indeed an important issue.

Currently commonly used microphones mainly include condenser microphones and MEMS (micro-electromechanical system) microphones, and condenser microphones are widely used due to their low cost. The most mainstream of condenser microphones is the electret microphone.

Fig. 4 shows a structure of an existing electret microphone related to the present invention. The existing electret microphone 10' mainly includes a cover body 11', a diaphragm group 12' housed in the cover body 11', a gasket 13', opposite to the diaphragm group 12' and separated by the gasket 13' The electret 14', the insulating ring 15' for accommodating the electret 14', the connecting ring 16' electrically connected to the electret 14' and the circuit board 17'. The cover 11' is provided with a sound hole 110' to receive an external sound source, and the diaphragm group 12' includes a diaphragm 121' and a diaphragm ring 122' supporting the diaphragm 121'. The diaphragm ring 122' is electrically connected to the circuit board through the cover 11', and the electret 14' is insulated from the diaphragm group 12' and the cover 11' by the insulating ring 15', and is connected through the connecting ring 16' on the circuit board 17'. Therefore, through the above-mentioned electrical connection relationship, a capacitive effect can be realized between the electret 14' and the diaphragm group 12'. When the external sound source enters the cover body 11', the diaphragm group 12' is vibrated to cause the distance between it and the electret 14' to change, which in turn causes the capacitance between the two to change, causing the current to change. Thereby converting sound waves into electrical signals.

Before the conventional microphone is finished, the bottom end of the cover 11' needs to be bent to fix the circuit board 17' and accommodate other components therein. During the bending process, a large mechanical force is required, which can easily bend and deform the circuit board 17' with low strength, or even break it, resulting in defective products.

Therefore, it is necessary to provide a new electret microphone to overcome the above disadvantages.

【Content of utility model】

The purpose of this utility model is to provide a new electret microphone, which can avoid deformation and damage of components during the manufacturing process.

The purpose of this utility model is achieved in that:

An electret microphone, which mainly includes a shell, a circuit board, a diaphragm group, a gasket and a back plate, and the gasket is located between the diaphragm group and the back plate for A gap is formed, the shell is provided with a bottom wall and a perforation surrounded by the bottom wall, the circuit board is seated on the bottom wall, and the shell is further provided with a sealing edge at its upper end, and the sealing edge abuts against the back plate.

As an improvement of the electret microphone of the present invention, the circuit board is provided with several welding feet, and these welding feet extend outward from the perforation of the shell, and the distance from the bottom surface of the welding feet to the sealing edge shall not be less than the distance from the bottom wall to the sealing edge. distance.

As another improvement of the electret microphone of the utility model, the circuit board is provided with a sound inlet hole at its central position, and the sound inlet hole communicates with the perforation of the shell.

Compared with the prior art, the utility model has the following advantages: the sealing end of the shell is at the position of the back plate, the back plate has high strength and is not easily deformed, while the circuit board is only accommodated in the shell and will not be deformed by force.

【Description of drawings】

Fig. 1 is the three-dimensional exploded schematic diagram of the utility model electret microphone;

Fig. 2 is the combined sectional view of the utility model electret microphone;

Fig. 3 is a cross-sectional view of the utility model electret microphone applied to terminal products;

Fig. 4 is a three-dimensional exploded schematic diagram of an existing electret microphone related to the present invention.

【Detailed ways】

The specific structure of the utility model electret microphone will be described in detail below in conjunction with the accompanying drawings.

Please refer to FIG. 1 , the electret microphone 10 of the present invention includes a housing 11 , a circuit board 12 , a diaphragm assembly 13 , a gasket 14 and a back plate 15 .

The housing 11 is ring-shaped and includes a side wall 111 , a bottom wall 112 extending perpendicular to the side wall 111 , and a perforation 113 formed around the bottom wall 112 . The side wall 111 is provided with a sealing edge 114 .

The shape of the circuit board 12 is matched with the housing 11, and it is provided with a main body 121, a conductive layer 122 arranged on the main body 121, a circuit driver chip 123 and a passive element 124 arranged on the main body 121, and a sound inlet provided at the center of the main body 121. For the hole 125, referring to FIG. 2 at the same time, a plurality of soldering pins 126 are provided on the bottom surface of the circuit board 12.

The shape of the diaphragm group 13 is also matched with the housing 11 , and it includes a bracket 131 and a diaphragm 132 supported by the bracket 131 .

The gasket 14 includes an annular frame 141 and a central hole 142 surrounded by the frame 141 .

An electret is arranged on the back plate 15 . Electret is a dielectric that can maintain an electric polarization state for a long time. This dielectric is a high molecular polymer, and free charges are distributed on the electret. Since there are free charges distributed on the electret, there is charge between the two poles of the capacitor formed between the diaphragm group 13 and the back plate 15. When the sound wave causes the diaphragm 132 to vibrate and generate displacement, the The capacitance of the capacitor, the change of the capacitance makes the output terminal of the capacitor generate a corresponding alternating electric field, which forms an electrical signal corresponding to the acoustic wave signal, thus completing the function of acoustic-electric conversion.

Please refer to FIG. 2 together. When assembling the microphone of the present invention, the circuit board 12 is first placed on the bottom wall 112 of the housing 11. The bottom wall 112 restricts the downward movement of the circuit board 12, and the side wall 111 restricts the radial movement of the circuit board 12. , the welding pin 126 provided on the circuit board 12 extends outward through the perforation 113 of the housing 11; the diaphragm group 13 is placed on the circuit board 12, and the diaphragm group 13 is connected to the conductive layer 122 on the circuit board 12; Place the spacer 14 on the diaphragm group 13; then place the back plate 15 on the spacer 14, the back plate 15 is separated from the diaphragm group 13 by a certain distance through the spacer 14, and the middle hole of the spacer 14 , forming a gap between the back plate 15 and the diaphragm group 13 ; finally, the sealing edge 114 of the shell 11 is bent and pressed against the back plate 15 . Thus, the back plate 15 , the gasket 14 , the diaphragm group 13 and the circuit board 12 are fixed in the casing 11 by the sealing edge 114 and the bottom wall 112 of the casing 11 , and the whole package is completed.

FIG. 3 shows a schematic diagram of the electret microphone 10 of the present invention being used in a terminal device, such as a mobile phone. In this figure, the electret microphone 10 is welded on the motherboard 20 of the terminal device. The motherboard 20 is provided with a sound hole 21 , and the sound hole 21 communicates with the sound inlet hole 125 . The welding pin 126 is welded to the corresponding circuit of the motherboard 20 through the perforation 113 of the shell 11, which requires that the bottom surface of the soldering pin 126 is at least flush with the bottom wall 112 of the shell 11, that is, the distance between the soldering pin 126 and the motherboard 20 The distance from the bottom wall 112 to the motherboard 20 should not be greater than the distance from the bottom wall 112 to the main board 20 , or, referring to the structure of the microphone itself, the distance from the bottom surface of the soldering pin 126 to the sealing edge 114 should not be smaller than the distance from the bottom wall 112 to the sealing edge 114 . Of course, if the design requires that the distance from the bottom surface of the welding leg 126 to the sealing edge 114 be smaller than the distance from the bottom wall 112 to the sealing edge 114, it can also be compensated by increasing the thickness of the solder paste for soldering.

Compared with the prior art, the sealing edge 114 of the electret microphone 10 of the present invention is on the side of the back plate 15 with higher strength, and the mechanical force of bending the sealing edge 114 is not easy to deform the back plate 15, which can Avoid the damage of the circuit board caused by bending the casing in the prior art.

The description and drawings show that each component is in the shape of a circle. In fact, it is not limited to the shape of a circle, as long as the sealing edge is on the side of the back plate to prevent damage to the circuit board or other components.

The above are only preferred embodiments of the present utility model, and the protection scope of the present utility model is not limited to the above-mentioned embodiments, but any equivalent modification or change made by those of ordinary skill in the art according to the content disclosed in the present utility model, All should be included in the scope of protection described in the claims.

Claims (3)

1. electret microphone, it mainly comprises shell, circuit board, vibrating diaphragm group, pad and back pole plate, pad between vibrating diaphragm group and the back pole plate in order between vibrating diaphragm group and back pole plate, to form the gap, it is characterized in that: the perforation that shell is provided with diapire and is enclosed to form by this diapire, circuit board is sat and is located on the diapire, shell is provided with the limit of sealing that is positioned at its upper end in addition, and this seals the limit and is connected on the back pole plate.

2. electret microphone as claimed in claim 1 is characterized in that: circuit board is provided with some welding foots, and these welding foots are stretched out by the perforation of shell, and the bottom surface of welding foot must not be less than diapire to the distance of sealing the limit to the distance of sealing the limit.

3. electret microphone as claimed in claim 1 is characterized in that: circuit board is provided with tone-entering hole in its middle position, and this tone-entering hole communicates with the perforation of shell.

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