MEMS microphone

The present disclosure discloses a MEMS microphone including a printed circuit board, a shell assembled with the printed circuit board for forming a receiving space and provided with a sound hole communicating with the receiving space, a MEMS Die with a cavity accommodated in the receiving space and mounted on the shell for covering the sound hole, and an ASIC chip accommodated in the receiving space and mounted on the shell through a substrate. The cavity of the MEMS Die communicates with the sound hole. The MEMS Die electrically connects with the ASIC chip. The ASIC chip electrically connects with the substrate. The substrate electrically connects with the printed circuit board.

FIELD OF THE PRESENT DISCLOSURE

The present disclosure relates to microphones, in particular to a micro-electro-mechanical system (MEMS) microphone.

DESCRIPTION OF RELATED ART

With the development of wireless communications, mobile phones are increasing. The requirements for mobile phones are not only to make calls, but also to be able to provide high-quality call effects. Especially, with the popularization of the mobile multimedia, the quality of the calls is more and more important. The microphone used as a voice pickup device of the mobile phone directly affects the quality of the calls. Currently, MEMS microphones are the most widely used.

A MEMS microphone in the related art includes a printed circuit board, a shell assembled with the printed circuit board, an ASIC chip mounted on the printed circuit board, and a MEMS Die with a cavity mounted on the printed circuit board. The shell has a sound hole for receiving external sounds. The printed circuit board encloses the cavity of the MEMS Die for making the cavity serve as a rear cavity of the MEMS microphone. The related MEMS microphone has a small rear cavity, thereby causing a lower SNR and seriously limiting the performance.

Thus, it is necessary to provide a novel MEMS microphone to solve the problem.

SUMMARY OF THE DISCLOSURE

A MEMS microphone disclosed in the present disclosure includes a printed circuit board, a shell assembled with the printed circuit board for forming a receiving space and provided with a sound hole communicating with the receiving space, a MEMS Die with a cavity accommodated in the receiving space and mounted on the shell for covering the sound hole, and an ASIC chip accommodated in the receiving space and mounted on the shell through a substrate. The cavity of the MEMS Die communicates with the sound hole. The MEMS Die electrically connects with the ASIC chip. The ASIC chip electrically connects with the substrate. The substrate electrically connects with the printed circuit board.

Further, the shell is made of a metal material.

Further, the MEMS microphone includes a conductive pillar electrically connecting the printed circuit board and the substrate.

Further, the MEMS microphone includes an insulating connection bridge wrapping the conductive pillar. The insulating connection bridge connects the printed circuit board and the substrate.

Further, the MEMS microphone includes a first bond wire. The substrate is provided with a conductive path therein. The conductive path electrically connects with the conductive pillar. The first bond wire electrically connects the ASIC chip and the conductive path.

Further, the printed circuit board is provided with a bond pad on an outer surface thereof. The conductive pillar connects with an inner surface of the printed circuit board and electrically connects with the bond pad through an inner circuit of the printed circuit board.

Further, the MEMS microphone includes a second bond wire. The second bond wire electrically connects the MEMS Die and the ASIC chip.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

The present disclosure will hereinafter be described in detail with reference to an exemplary embodiment. To make the technical problems to be solved, and technical solutions and beneficial effects of the present disclosure more apparent, the present disclosure is described in further detail together with the FIG. and the embodiment. It should be understood the specific embodiment described hereby is only to explain the disclosure, not intended to limit the disclosure.

Referring toFIG.1, the present disclosure discloses a MEMS microphone100, which includes a printed circuit board10, a shell20assembled with the printed circuit board10for forming a receiving space30, a MEMS Die40accommodated in the receiving space30, and an ASIC chip50accommodated in the receiving space30. Optionally, the shell20is made of a metal material, since a metal shell has a strong structural strength and is benefit to realize electromagnetic shielding.

The shell20is provided with a sound hole21communicating with the receiving space30. The MEMS Die40is mounted on the shell20and covers the sound hole21. The MEMS Die40has a cavity41communicating with the sound hole21. The MEMS Die40divides the receiving space30into a front cavity and a rear cavity of the MEMS microphone100. The cavity41of the MEMS Die40serves as the front cavity of the MEMS microphone100, the rest of the receiving space30enclosed by the MEMS Die40, the shell20and the printed circuit board10serves as the rear cavity of the MEMS microphone100. Thus, the MEMS microphone100has a smaller front cavity and a larger rear cavity, thereby, greatly improving the sensitivity and enhancing the performance.

The ASIC chip50is mounted on the shell20through a substrate60. Optionally, the substrate60is glued to the shell20. The substrate60electrically connects with the printed circuit board10through a conductive pillar71. The substrate60is provided with a conductive path61therein, and it may choose a printed circuit board. The conductive path61electrically connects with the conductive pillar71. The ASIC chip50electrically connects with the conductive path61through a first bond wire81. The printed circuit board10is provided with a bond pad11on an outer surface10athereof, the bond pad11is used to electrically connect with an external circuit, the conductive pillar71connects with an inner surface10bof the printed circuit board10and electrically connects with the bond pad11through an inner circuit10cof the printed circuit board10. Thus, the ASIC chip50realize electrical connection with an external circuit sequentially through the first bond wire81, the conductive path61, the conductive pillar71, the inner circuit10cand the bond pad11. The MEMS Die40electrically connects with the ASIC chip50through a second bond wire82. Thus, the MEMS microphone100has a simple structure for realizing electrical connection.

Optionally, the MEMS microphone100further includes an insulating connection bridge72. The insulating connection bridge72connects the printed circuit board10and the substrate60, so that the insulating connection bridge72wraps the conductive pillar71for preventing the conductive pillar71from damages.

Optionally, the ASIC chip50is wrapped with an encapsulating material51for preventing the ASIC chip50from the influences of temperature and humidity of external environment, static electricity, heat, particles, light and other factors.

Compared with the related art, the MEMS microphone100has a smaller front cavity and a larger rear cavity, thereby, greatly improving the sensitivity and enhancing the performance. Besides, the MEMS microphone100has a simple structure for realizing electrical connection and a lower cost.