| 摘要 |
A Z-axis structure in an accelerometer comprises a mass block (1) moving relative to a substrate (4) in a Z-axis direction in a reciprocating manner. A first movable electrode plate (10) and a second movable electrode plate (11) are disposed on a sidewall of the mass block (1). A first fixed electrode plate (20) and a second fixed electrode plate (30) extending toward a plane consisting of an X axis and a Y axis are also disposed on the sidewall of the mass block (1). According to the Z-axis accelerometer, a lower plate structure is discarded, therefore the limitation of a lower plate to the Z-axis accelerometer is avoided, the mass block (1) can move up and down in the Z-axis direction, rather than moving in a teeterboard moving manner, the parasitic capacitance of the Z-axis accelerometer is reduced, and the detection precision is improved; the contact between the movable mass block (1) and the substrate (4) is avoided, and therefore the chip reliability is improved; the mass block (1) and the fixed electrodes are located at a same layer, therefore the consistence is superior to that of the traditional Z-axis structure; in addition, anchor points can be centralized in design, so as to reduce the sensitivity of a chip to the changes of the temperature and stress. |
