Accelerometer

An accelerometer, comprising:

• a substrate (100) comprising an anchor point (101);
• an external coupling unit (1) parallel to the substrate (100) and configured as a co-inspection quality for XYZ three-axis detection, including an avoidance hole in the middle;
• a first torsion plate (2) located in the avoidance hole, connected to the anchor point (101) through a first torsion beam (11);
• a second torsion plate (3) located in the avoidance hole, connected to the anchor point (101) through a second torsion beam (14);
• two external coupling elastic components (4) configured to provide elastic support for the external coupling unit (1), one of the external coupling elastic components configured to connect the first torsion plate (2) and the external coupling unit (1), the other of the external coupling elastic components configured to connect the second torsion plate (3) with the external coupling unit (1);
• an in-plane detection device disposed in the external coupling unit (1), configured to detect movements of the external coupling unit (1) in a first direction (X) and a second direction (Y);
• and
• an out-of-plane detection device configured to detect movements of the first torsion plate (2) and the second torsion plate (3) in a third direction (Z);
• wherein
• the external coupling unit (1) is in a rectangular shape and provided with a first central axis (A) parallel to the first direction (X) and a second central axis (B) parallel to the second direction (Y), a symmetry center of the external coupling unit (1) is overlapped with a symmetry center of the anchor point (101);
• the first torsion plate (2) and the second torsion plate (3) are axially symmetrical about the first central axis (A) respectively;
• the first torsion beam (11) and the second torsion beam (14) are both extended along the second direction (Y);
• the first torsion plate (2) and the second torsion plate (3) is connected through an inner coupling beam (7) extended along the second direction (Y);
• when an acceleration in the third direction (Z) is detected, the first torsion plate (2) is configured to rotate around the first torsion beam (11), and the second torsion plate (3) is configured to rotate around the second torsion beam (14);
• the first torsion plate (2) and the second torsion plate (3) rotates in opposite directions;
• along the second direction (Y), a projection of the first torsion plate (2) is overlapped with a projection of the second torsion plate (3), the first torsion plate (2) and the second torsion plate (3) are mutually embedded to increase rotation radius of the first torsion plate (2) and the second torsion plate (3), thereby improving sensitivity of acceleration detection of the accelerometer in a third direction (Z).