公开(公告)号：WO1996017232A1

公开(公告)日：1996-06-06

申请号：PCT/US1995015284

申请日：1995-11-29

Applicant: ANALOG DEVICES, INC.

Inventor： ANALOG DEVICES, INC. ,  HOWE, Roger, T. ,  BART, Stephen

IPC: G01L01/14

CPC classification number: G01P15/125 ,  G01L1/148 ,  G01P15/131 ,  G01P2015/0814 ,  H01G5/14

Abstract: A micromachined force sensor containing separate sensing (38) and actuator (80) structures. A member (10) is suspended above the substrate so that it is movable along an axis (X) in response to a force. The member includes a set of parallel sense (38) fingers and a separate set of parallel force (80) fingers. The sense fingers are positioned between fingers of two sense plates (40, 42) to form a first differential capacitor, whose capacitance changes when the member moves in response to a force along the axis. The change in capacitance induces a sense signal on the member, which permits the measurement of the magnitude and duration of the force. The force fingers are positioned between fingers of two actuator plates (82, 84) to form a second differential capacitor. The sense signal can be used to provide feedback to the second differential capacitor to generate different electrostatic forces between the force fingers (80) and the two actuator plates (82, 84) to offset the force applied along the preferred axis. Limit stops (30) limit the movement of the member to less than the distance between the electrodes of the differential capacitors, to prevent contact between the electrodes. Additional fingers (100, 102, 104) are positioned around the differential capacitors to minimize parasitic capacitances.

Abstract translation: 包含单独的感测（38）和致动器（80）结构的微机械力传感器。 构件（10）悬挂在基板上方，使得其可以响应于力而沿轴线（X）移动。 该构件包括一组平行的手指（38）和一组单独的平行力（80）的手指。 感测指状物定位在两个感测板（40,42）的指状物之间，以形成第一差分电容器，当构件响应于沿着轴的力移动时，其电容发生变化。 电容的变化会引起元件上的感应信号，这样可以测量力的大小和持续时间。 力指定位于两个致动器板（82,84）的指状物之间，以形成第二差分电容器。 感测信号可以用于向第二差分电容器提供反馈以在力指（80）和两个致动器板（82,84）之间产生不同的静电力，以抵消沿着优选轴施加的力。 极限停止（30）将构件的移动限制为小于差动电容器的电极之间的距离，以防止电极之间的接触。 附加指状物（100,102,104）围绕差分电容器定位以最小化寄生电容。