MEMS microphone

The present application discloses a MEMS microphone, including: a substrate having a cavity; and a capacitor system mounted on the substrate. The capacitor includes a back plate connected to the substrate; and a diaphragm forming a capacitor with the back plate. The back plate includes a back plate main body and a first connecting portion extending from the back plate main body toward the substrate, the first connecting portion connects with the substrate, and the diaphragm connects to the back plate main body. The vibration or the stress from the substrate will not transferred to the diaphragm, but released via the first connecting portion.

FIELD OF THE PRESENT DISCLOSURE

The present disclosure relates to microphones, more particularly to a MEMS microphone.

DESCRIPTION OF RELATED ART

With the development of wireless communication technology, there are more and more mobile phone users in the world. The mobile phone users are no longer satisfied by the calling function of mobile phone, but require high quality call results. Especially in current development of mobile multimedia technology, mobile phone call quality is more important. The microphone of mobile phone is a voice pickup device in the mobile phone and its design will have a direct effect on call quality.

The microphone with more popularity and better performance at present is MEMS (Micro-Electro-Mechanical-Systems) microphone. A typical MEMS microphone includes a housing, a circuit board engaging with the housing to form a cavity, a MEMS chip and an ASIC chip received in the cavity.

During the mounting process, the MEMS microphone would be damaged due to thermal stress, incorrect (interference) assembly. The microphone will be distorted, and the transformation will be transferred to the MEMS chip, which will affect the stability of the microphone.

Therefore, it is desired that an improved MEMS microphone can overcome the disadvantages mentioned above.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

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

Referring toFIG. 1, a MEMS microphone100, in accordance with an exemplary embodiment of the present invention, includes a circuit board1, a substrate3mounted on the circuit board1, and a capacitor system5mounted on the substrate3.

The circuit board1is a printed circuit board, for outputting electrical signals and carrying internal components in the MEMS microphone1.

The substrate3is used for suspending the capacitor system5, and forms a cavity31cooperatively with the capacitor system5. The cavity31provides an accommodation space.

The capacitor system5includes a back plate51connected to the substrate3and a diaphragm53connected to the back plate51for forming a capacitor.

The back plate51includes a back plate main body511and a first connecting portion51extending from an edge of the back plate main body511toward the substrate3, and the first connecting portion51connects to the substrate3.

The diaphragm53includes a diaphragm main body531parallel to and spaced from the back plate main body511, and a second connecting portion533extending from an edge of the diaphragm main body531. The diaphragm main body531connects to the back plate main body511by the second connecting portion533. Especially, the diaphragm main body531is perpendicular to the second connecting portion533.

In the embodiment, the diaphragm main body531connects to a side of back plate511adjacent to the circuit board1by the second connecting portion533. The diaphragm53is accommodated in the cavity31. In fact, the diaphragm53can be connected to the side of the back plate511away from the cavity31, which means the diaphragm53is out of the cavity31.

The second connecting portion533is made of insulative material for separating the back plate main body511from the diaphragm main body531to form a capacitor. In the embodiment, the second connecting portion has a length smaller than a length of the first connecting portion513.

Referring toFIG. 2, a stress inducing diagram of a related MEMS microphone is shown. According to the diagram, the diaphragm suffers grater stress, and the compliance of the diaphragm is badly affected, which leads to worse sensitivity.

Referring toFIG. 3, a stress inducing diagram of the MEMS microphone of the present invention is shown. Compared toFIG. 2, it is noted that the diaphragm does not bear stress.

The MEMS microphone provided by the present invention is such configured that the diaphragm main body531is connected to the back plate main body511by the insulative second connecting portion533, not connected to the substrate3directly. Thus, the vibration or the stress from the substrate will not transferred to the diaphragm, but released via the first connecting portion513. Accordingly, the compliance of the diaphragm is ensured, and the sensitivity of the microphone is improved.