摘要:
PROBLEM TO BE SOLVED: To easily and precisely detect external force given to a piezoelectric piece and to suppress influences of electrostatic charge charged with the piezoelectric piece.SOLUTION: A crystal piece 2 is supported by a cantilever in a container 1. Excitation electrodes 31, 41 are formed on an upper surface and a lower surface of the crystal piece 2 respectively, a movable electrode 5 connected to the excitation electrode 41 is provided at a tip part on a lower surface side of the crystal piece 2, and a fixed electrode 6 is provided for a bottom part of the container 1. An oscillation loop which returns to an oscillation circuit via the excitation electrodes 31, 41, the movable electrode 5, and the fixed electrode 6 is formed, and a change of capacity between the electrodes 5 and 6 caused by warp of the crystal piece 2 due to external force given to the crystal piece is detected as a frequency. A switch 21 for opening/closing a static eliminated circuit for discharging electrostatic charge generated in the crystal piece 2 to a ground.
摘要:
PROBLEM TO BE SOLVED: To provide a simplified production process of a MEMS or a NEMS system, provided with an active structure having a mobile part and a fixed part formed of a stack of layers on a substrate, and provided with surfaces facing each other, wherein these surfaces can form, for example, stopping portions, or detection or operation electrodes, according to an application of the system. SOLUTION: The production process is provided, for producing a micromechanical structure comprising: a substrate and a stack of at least two layers arranged on the substrate; a mobile part formed in the stack and a fixed part relative to the substrate formed in the stack; and surfaces formed between the fixed part and the mobile part, and facing each other, the process for forming, for example, stop means to limit a displacement of the mobile part in a direction substantially perpendicular to the stack, and for using at least one sacrificial layer between the substrate and the stack made of a material suitable to be etched selectively relative to the materials of the stack. COPYRIGHT: (C)2011,JPO&INPIT
摘要:
PROBLEM TO BE SOLVED: To easily constitute a precise control structure for limiting the displacement of a heavy weight. SOLUTION: A method for manufacturing an acceleration sensor comprises the steps of preparing an SOI substrate having a three-layer structure of a silicon layer 100, a silicon oxide layer 20 and a silicon layer 300, conducting inductively coupled plasma etching capable of selectively removing only silicon from the upper surface, opening slits S1, S2, conducting similar etching for the lower surface from down below, forming grooves G1, G3, and separating the layer 300 into the heavy weights 310 and a pedestal 330 (Fig. (a)). The method further comprises the steps of dipping only the silicon oxide in a selectively removable etching liquid, removing the exposed part in the vicinity of the silicon oxide layer 20, forming a connecting layer 200 (Fig. (b)), and connecting a glass board 400 to the bottom of the pedestal 330. The method also comprises the steps of forming a piezo resistance element on the upper surface of the layer 100, and detecting the deflection. The degrees of freedom of the displacement in the upward direction of the weights 310 are accurately set according to the thickness of the layer 300. COPYRIGHT: (C)2004,JPO