CN101646120A - Capacitance microphone - Google Patents

Abstract

The invention provides a capacitance microphone, comprising a circuit board, a frame and an upper board, wherein, the frame is connected with the circuit board, and the upper board is connected with the frame. The circuit board, the frame and the upper board form a protection structure, a microcomputer electric chip which is arranged in the protection structure and is provided with a back cavity and a control circuit chip which is electrically connected with the microcomputer electric chip, a second sound hole which is communicated with the inside of the protection structure and a first soundhole which is used for receiving outside sound are arranged on the circuit board, spaced transversely and communicated by an air gap, and a dust screen is arranged in the air gap and at least covers the first sound hole. In the capacitance microphone with the structure, the dust screen is arranged on the circuit board, dust can be prevented from entering the circuit board, the problem of malfunction or large sensitivity change of the capacitance microphone caused by the entering of the dust is avoided, and the property of the capacitance microphone is enhanced.

Description

condenser microphone

technical field

The invention relates to a microphone, in particular to a condenser 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.

At present, the microphone with more applications and better performance is a micro-electro-mechanical-system microphone (Micro-Electro-Mechanical-System Microphone, referred to as MEMS). In related technologies, referring to FIG. A frame 12' connected to the circuit board 11' and an upper plate 13' connected to the frame 12', wherein the circuit board 11', the frame 12' and the upper plate 13' constitute a protective structure, and the MEMS chip 17' and the control circuit 16' is located in this protective structure. Wherein, the sound inlet hole 14' positioned on the circuit board 11' is opposite to the back cavity 171' of the MEMS chip 17', and dust is easily entered during the process of taking the MEMS chip 17', carrying out the drop test and SMT installation process, thereby causing Micro-electromechanical system microphone 1' fails or changes greatly in sensitivity, and at the same time, since the circuit board 11' is finally pasted on the client side by SMT process, it is impossible to paste the dust-proof net on the circuit board 11'. Therefore, it is necessary to provide a novel MEMS microphone.

Contents of the invention

The technical problem to be solved by the present invention is to provide a condenser microphone with good performance.

In order to solve the problems of the technologies described above, the technical solution provided by the invention is:

A condenser microphone, comprising a circuit board, a frame connected to the circuit board and an upper plate connected to the frame, the circuit board, the frame and the upper plate form a protective structure, and the micro-electromechanical chip with a back cavity and the The control circuit chip electrically connected to it is provided with a second sound hole communicating with the inside of the protective structure and a first sound hole for receiving external sound on the circuit board, the first sound hole and the second sound hole are laterally spaced and It is connected by an air gap, and a dust-proof net is arranged in the air gap, and the dust-proof net covers at least the first sound hole.

Preferably, the micro-electromechanical chip is electrically connected to the control circuit chip by binding gold wires.

Preferably, the second acoustic hole is opposite to and communicated with the back cavity of the micro-electromechanical chip.

Preferably, the circuit board has a three-layer structure, the circuit board on the first layer is connected to the frame, the circuit board on the second layer is connected to the circuit board on the first layer, the circuit board on the third layer is connected to the circuit board on the second layer, and the circuit board on the second layer is connected to the circuit board on the second layer. The hole is arranged on the first layer of circuit board, the first sound hole is arranged on the third layer of circuit board, the second layer of circuit board is provided with an air gap, and the dust-proof net is placed in the air gap.

The present invention also provides a condenser microphone, which includes a circuit board and a shell connected to the circuit board. The circuit board and the shell form a protective structure, and a micro-electromechanical chip with a back cavity and a control device electrically connected to the protective structure are provided. The circuit chip is provided with a second sound hole communicating with the inside of the protective structure and a first sound hole for receiving external sound on the circuit board, the first sound hole and the second sound hole are laterally spaced and communicated through an air gap, A dust-proof net is arranged in the air gap, and the dust-proof net covers at least the first sound hole.

The beneficial effect of the present invention is that: the circuit board is provided with a dust-proof net, which can prevent dust from entering, avoiding the failure of the condenser microphone or the large sensitivity change caused by the dust entering, and improving the performance of the condenser microphone.

Description of drawings

Fig. 1 is the sectional view of the microphone relevant to the present invention;

Figure 2 is a cross-sectional view of an embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

The condenser microphone provided by the invention is mainly used in mobile phones to receive sound and convert the sound into electrical signals.

2, the condenser microphone 1 provided by the present invention includes a circuit board 11, a frame 12 connected to the circuit board 11 and an upper plate 13 connected to the frame 12, and the circuit board 11, the frame 12 and the upper plate 13 constitute a protective structure.

The micro-electromechanical chip 17 and the control circuit chip 16 electrically connected to it are placed in a protective structure composed of the circuit board 11 , the frame 12 and the upper board 13 . The micro-electro-mechanical chip 17 and the control circuit chip 16 can all be placed on the circuit board 11, and can also be all placed on the upper board 13. Certainly, the micro-electro-mechanical chip 17 can also be placed on the circuit board 11, and the control circuit chip 16 can be placed on the circuit board 13. The upper board 13 or the micro-electromechanical chip 17 is placed on the upper board 13 , and the control circuit chip 16 is placed on the circuit board 11 . The micro-electromechanical chip 17 and the control circuit chip 16 can be electrically connected by binding gold wires, or can be electrically connected by other methods.

The circuit board 11 is provided with a first sound hole 14 and a second sound hole 15, the first sound hole 14 and the second sound hole 15 are laterally spaced and communicated through an air gap 145, and the dust-proof net 18 is placed in the air gap 145 . The dustproof net 18 may cover the first sound hole 14 or the second sound hole 15 , or may cover the first sound hole 14 and the second sound hole 15 entirely. The first sound hole 14 is used to receive external sound, and the second sound hole 15 communicates with the inside of the protection structure.

In an embodiment provided by the present invention, the circuit board 11 has a three-layer structure, the first layer of circuit board 11 is connected to the frame 12, the second layer of circuit board 12 is connected to the first layer of circuit board 11, and the third layer of circuit board 13 It is connected with the circuit board 12 on the second layer, the second sound hole 15 is set on the circuit board 11 on the first layer, the first sound hole 14 is set on the circuit board 13 on the third layer, and the circuit board on the second layer is provided with an air gap 145 to prevent dust The mesh 18 is placed in this air gap 145 . Of course, the circuit board 11 is not limited to a three-layer structure, as long as the first sound inlet hole 14 and the second sound inlet hole 15 are connected through the air gap 145, and the dustproof net 18 is placed in the air gap 145, it belongs to the protection of the present invention. range. Since the dust-proof net 18 is set on the circuit board 11 , dust can be prevented from entering, the problem of failure of the condenser microphone 1 or large sensitivity change caused by the entry of dust is avoided, and the performance of the condenser microphone 1 is improved.

The second acoustic hole 15 can be opposite to the back cavity 171 of the micro-electromechanical chip 17, which can better improve the acoustic performance. When the second acoustic hole 15 is opposite to the back cavity 171 of the micro-electromechanical chip 17 , it communicates with the back cavity 171 .

Of course, the frame 12 and the upper board 13 can also be an integrally formed casing, which together with the circuit board 11 constitutes a protective structure.

What has been described above is only one embodiment of the present invention. It should be pointed out that, for those of ordinary skill in the art, improvements can be made without departing from the creative concept of the present invention, but these all belong to protection scope of the present invention.

Claims (5)

1. A condenser microphone, comprising a circuit board, a frame connected to the circuit board and an upper plate connected to the frame, the circuit board, the frame and the upper plate constitute a protective structure, and the micro-electromechanical device provided with a back cavity in the protective structure The chip and the control circuit chip electrically connected to it are characterized in that: the circuit board is provided with a second sound hole communicating with the inside of the protective structure and a first sound hole for receiving external sound, the first sound hole and the second sound hole The two sound holes are laterally spaced apart and communicated through an air gap, and a dust-proof net is arranged in the air gap, and the dust-proof net covers at least the first sound hole. 2. The condenser microphone according to claim 1, wherein the micro-electromechanical chip and the control circuit chip are electrically connected by binding gold wires. 3. The condenser microphone according to claim 1, wherein the second sound hole is opposite to and communicated with the back cavity of the MEMS chip. 4. The condenser microphone according to claim 1, characterized in that: the circuit board has a three-layer structure, the first layer of circuit board is connected with the frame, the second layer of circuit board is connected with the first layer of circuit board, and the third layer of circuit board is connected with the frame. The circuit board is connected to the circuit board on the second layer, the second sound hole is set on the first layer circuit board, the first sound hole is set on the third layer circuit board, the second layer circuit board is provided with an air gap, and an anti- dust net. 5. A condenser microphone, comprising a circuit board and a shell connected to the circuit board, the circuit board and the shell form a protective structure, a micro-electromechanical chip with a back cavity and a control circuit chip electrically connected to the protective structure are arranged, It is characterized in that: the circuit board is provided with a second sound hole communicating with the inside of the protective structure and a first sound hole for receiving external sound, the first sound hole and the second sound hole are laterally spaced and communicated through an air gap , a dust-proof net is set in the air gap, and the dust-proof net covers at least the first sound hole.

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