CN204377143U - The encapsulating structure of micro-electro-mechanical microphone - Google Patents

Abstract

The utility model provides a packaging structure of a micro-electromechanical microphone, which comprises a circuit board, a housing assembled with the circuit board to form an accommodating space, and a casing accommodated in the accommodating space and electrically connected to the circuit board. The electronic component includes a base shell and at least two layers of shielding shells covering the base shell, at least one of the at least two layers of shielding shells is metal plating. With the micro-electromechanical microphone packaging structure of the utility model, better electromagnetic shielding effect can be realized.

Description

Package Structure of MEMS Microphone

【Technical field】

The utility model relates to a micro-electromechanical microphone, in particular to a package structure of a micro-electromechanical system micro-electromechanical microphone.

【Background technique】

Due to the advancement of technology, micro-electro-mechanical microphones have considerable advantages in terms of function and size, but because micro-electro-mechanical microphones must receive external sounds, they are easily interfered by external factors (such as electromagnetic waves) and cause reception Poor quality, which in turn leads to the associated impact on the added value of related electronic products. Therefore, how to improve the effect of preventing electromagnetic interference is the most urgent problem in the industry.

However, the traditional micro-electromechanical microphones that are widely used at present are assembled with a single metal cover on the PCB to provide electromagnetic shielding for the microphone chip. With the rapid increase in the number and types of electronic components in electronic equipment using microelectromechanical microphones, the electromagnetic environment in which microelectromechanical microphones are located is becoming more complex and changeable. At this time, the defects of the electromagnetic shielding structure of a single metal cover are becoming more and more apparent. It is already difficult to adapt to this complex and changeable electromagnetic environment, which makes the electromagnetic interference received by the microphone chip more obvious, which seriously affects the performance of the MEMS microphone.

Therefore, it is necessary to provide a new packaging structure for micro-electromechanical microphones.

【Content of utility model】

The purpose of the utility model is to provide a packaging structure of a micro-electromechanical microphone with good waterproof and dustproof performance.

The technical scheme of the utility model is as follows: provide a packaging structure of a micro-electromechanical microphone, including a circuit board, a housing assembled with the circuit board to form an accommodation space, and a housing that is accommodated in the accommodation space and connected to the circuit board Electrically connected electronic components, the housing includes a base shell and at least two layers of shielding shells covering the base shell, at least one of the at least two layers of shielding shells is metal plating.

Preferably, the housing includes a first metal coating coating an outer surface of the base shell and a second metal coating coating an outer surface of the first metal coating.

Preferably, the first metal coating layer and the second metal coating layer are made of different kinds of metals.

Preferably, the casing includes a third metal plating layer coated on the outer surface of the base shell, and a first shielding shell disposed outside the third metal plating layer.

Preferably, the first shielding shell is made of a metal material different from the third metal plating layer.

Preferably, the first shielding shell is fixed on the circuit board.

Preferably, the outer surface of the first shielding shell is flush with the end surface of the circuit board.

Preferably, the housing includes a second shielding housing that is disposed outside the base shell and a fourth metal plating layer that is plated on the outer surface of the second shielding housing.

Preferably, the second shielding shell is made of a metal material different from the fourth metal plating layer.

Preferably, at least one layer of the at least two shielding shells is electrically connected to the circuit board.

The beneficial effect of the utility model is that the resistance of the micro-electromechanical microphone to external electromagnetic interference is improved by arranging a multi-layer shielding shell outside the base shell, thereby improving its overall quality.

【Description of drawings】

Fig. 1 is the cross-sectional view of the MEMS microphone provided by the first embodiment of the utility model;

Fig. 2 is the enlarged view of place A in Fig. 1;

3 is a cross-sectional view of the micro-electromechanical microphone provided by the second embodiment of the present invention;

Fig. 4 is a cross-sectional view of the MEMS microphone provided by the third embodiment of the present invention.

【Detailed ways】

The concrete content of the present utility model is described in detail below in conjunction with accompanying drawing.

The micro-electromechanical microphone 100 of the utility model can be used on mobile phones or other electronic devices to receive acoustic signals and convert the acoustic signals into electrical signals.

Please refer to Fig. 1 and Fig. 2, the MEMS microphone 100 provided by the first embodiment of the present utility model mainly includes a housing 1, a circuit board 2 assembled with the housing 1 and forming an accommodating space 5, arranged in the accommodating space 5 The transducer 3 inside, and the integrated chip 4 arranged in the accommodation space 5 and electrically connected with the transducer 3 . The transducer 3 is used to receive the sound wave entering the accommodation space and convert it into an electrical signal, and the generated electrical signal is transmitted to the integrated chip 4, and then output to an external circuit by the integrated chip 4, thereby converting the sound into an electrical signal. In this embodiment, both the transducer 3 and the integrated chip 4 are arranged on the circuit board 2, in fact, the transducer 3 and the integrated chip 4 can also be placed on the housing 1, or one of them is placed on the circuit board 2 , and the other is placed on the shell 1. In this embodiment, the transducer 3 and the integrated chip 4 are electronic components.

In this embodiment, the casing 1 includes a base shell 10 having an inner surface 101 facing the accommodation space 5 and an outer surface 102 opposite thereto, and a first metal plating layer 11 plated on the outer surface of the base shell 10 And the second metal coating 12 coated on the outer surface of the first metal coating 11 . In this embodiment, the base housing 10 is made of plastic such as silicone. The first metal coating layer 11 and the second metal coating layer 12 are formed by depositing different kinds of metals. This can achieve shielding from external electromagnetic interference. The number of metal plating layers is not limited to the two layers in this embodiment, and a variety of different metal layers can be deposited according to actual needs to improve the shielding effect. In other embodiments, the base casing 10 may also be made of a different type of metal material than the metal plating layer. At least one of the two metal plating layers 11, 12 is electrically connected to the circuit board 2 for grounding.

With reference to Fig. 2, the main difference between the microelectromechanical microphone 200 provided by the second embodiment of the present invention and the microelectromechanical microphone 100 in the first embodiment is: the structure of the housing 1a of the microelectromechanical microphone 200 is different, and the rest The structures and assembly methods of the circuit board 2a, the transducer 3a, the integrated chip 4a, etc. are the same as those of the first embodiment.

In this embodiment, the casing 1a includes a base housing 21 having an inner surface 201 facing the accommodation space 5a and an outer surface 202 opposite thereto, and a third metal plating layer plated on the outer surface 202 of the base housing 21 22 and the first shielding shell 23 that is provided outside the third metal plating layer 22 . The first shielding shell 23 is made of a metal material different from the third metal plating layer. The first shielding shell 23 covers the entire base shell 21 and is spaced a certain distance from the base shell 21 to form an electromagnetic shielding space. The first shielding shell 23 is fixed on the circuit board 2a by bonding or welding and is electrically connected with the circuit board 2a. Preferably, its outer surface is flush with the end surface of the circuit board 2a. In other embodiments, the outer surface of the first shielding shell 23 may be coated with one or more metal coatings different from the third metal coating.

Referring to Fig. 3, the main difference between the MEMS microphone 300 provided by the third embodiment of the present invention and the MEMS microphones provided by the first two embodiments is that the structure of the housing 1b of the MEMS microphone 300 is different, and the rest The structures and assembly methods of the circuit board 2b, transducer 3b, integrated chip 4b, accommodating space 5b, etc. are the same as those of the first embodiment.

In this embodiment, the housing 1 b includes a base shell 31 , a second shielding shell 32 covering the base shell 31 , and a fourth metal plating layer 33 plated on the outer surface of the second shielding shell 32 . The second shielding shell 32 is made of a metal different from the fourth metal plating 33 . The second shielding shell 32 covers the entire base shell 31 and is separated from the base shell 31 by a certain distance to form an electromagnetic shielding space. The second shielding case 32 is fixed on the circuit board 2b by bonding or welding and is electrically connected with the circuit board 2b. In order to further enhance the effect of electromagnetic shielding, multiple layers of different metal coatings may be deposited on the second shielding shell 32 .

With the micro-electro-mechanical microphone packaging structure of the utility model, good electromagnetic shielding can be realized, the external electromagnetic field can be prevented from interfering with the internal sound wave signal, and the overall quality of the micro-electro-mechanical microphone can be improved.

What has been described above is only the embodiment of the utility model, and it should be pointed out that for those of ordinary skill in the art, improvements can also be made without departing from the inventive concept of the utility model, but these all belong to Protection scope of the present utility model.

Claims (10)

1. A packaging structure for a micro-electromechanical microphone, comprising a circuit board, a housing assembled with the circuit board and forming an accommodation space, and an electronic component housed in the accommodation space and electrically connected to the circuit board , characterized in that the housing includes a base shell and at least two layers of shielding shells covering the base shell, at least one of the at least two layers of shielding shells is metal plating. 2. The packaging structure of the micro-electromechanical microphone according to claim 1, wherein the housing includes a first metal coating that coats the outer surface of the base shell and a metal coating that is coated on the first metal coating. A second metal coating on the outer surface. 3 . The packaging structure of the MEMS microphone according to claim 2 , wherein the first metal plating layer and the second metal plating layer are made of different types of metals. 4 . 4. The packaging structure of the micro-electromechanical microphone according to claim 1, wherein the housing includes a third metal plating layer coated on the outer surface of the base shell and a cover provided on the third metal plating layer outside the first shielding case. 5 . The packaging structure of the MEMS microphone according to claim 4 , wherein the first shielding shell is made of a metal material different from the third metal plating layer. 6 . The packaging structure of the MEMS microphone according to claim 4 , wherein the first shielding case is fixed on the circuit board. 7 . The packaging structure of the MEMS microphone according to claim 6 , wherein the outer surface of the first shielding case is flush with the end surface of the circuit board. 8. The packaging structure of the micro-electromechanical microphone according to claim 1, wherein the housing includes a second shielding housing that is placed outside the base housing and is plated on the second shielding housing. The fourth metal coating on the outer surface of the 9 . The packaging structure of the MEMS microphone according to claim 8 , wherein the second shielding shell is made of a metal material different from the fourth metal plating layer. 10 . The packaging structure of the MEMS microphone according to claim 1 , wherein at least one layer of the at least two shielding shells is electrically connected to the circuit board. 11 .