Condenser MEMS microphone and electronic apparatus
Disclosed are a condenser MEMS microphone and an electronic apparatus. The condenser MEMS microphone comprises: a substrate; a bottom plate placed on the substrate; and a top plate placed above the bottom plate and spaced from the bottom plate, wherein the top plate is torsional with respect to a first torsional axis and is divided into a first part and a second part by the first torsional axis, the first part and the second part form two condensers with the bottom plate, and a first group of acoustic holes are provided in the first part of the top plate.
1. A condenser MEMS microphone, comprising:
a substrate;
a bottom plate placed on the substrate; and
a top plate placed above the bottom plate and spaced from the bottom plate,
wherein the top plate is torsional with respect to a first torsional axis and is divided into a first part and a second part by the first torsional axis, the first part and the second part from two condensers with the bottom plate, and a first group of acoustic holes are provided in the first part of the top plate, and
wherein the bottom plate is torsional with respect to a second torsional axis and is divided into a third part and a fourth part by the second torsional axis, the second torsional axis corresponds to the first torsional axis, and the third part and the fourth part correspond to the first part and the second part, respectively.
2. The condenser MEMS microphone according to claim 1 , wherein the top plate is placed on the substrate at the ends of the first torsional axis.
3. An electronic apparatus, comprising a condenser MEMS microphone according to claim 2 .
4. The condenser MEMS microphone according to claim 1 , wherein the bottom plate is placed on the substrate at the ends of the second torsional axis.
5. The condenser MEMS microphone according to claim 1 , wherein a second group of acoustic holes are provided in the fourth part of the bottom plate.
6. The condenser MEMS microphone according claim 1 , wherein at least one of the top and bottom plates are stiff enough in out-of-plane movement, compared to torsional stiffness.
7. The condenser MEMS microphone according to claim 1 , wherein a first electrode is placed on the first part, a second electrode is placed on the second part, a center electrode is placed on the bottom plate, and the first and second electrodes are used for providing differential sensing signals.
8. The condenser MEMS microphone according to claim 7 , wherein the top plate is of polycrystalline silicon, and the first and second electrodes are isolated by patterning of doping.
9. The condenser MEMS microphone according to claim 1 , wherein the top and bottom plates are placed on the substrate via a dielectric layer.
10. An electronic apparatus, comprising a condenser MEMS microphone according to claim 1 .