Capacitive vibration sensor

摘要

A hollow part is formed in a silicon substrate through the front and the back. A vibration electrode plate is arranged on an upper surface of the silicon substrate to cover the opening on the upper surface. A fixed electrode plate covers the upper side of the vibration electrode plate while maintaining a microscopic gap with the vibration electrode plate, where the peripheral part is fixed to the upper surface of the silicon substrate. The fixed electrode plate has the portion facing the upper surface of the silicon substrate through a space supported by a side wall portion arranged on an inner edge of the portion fixed to the upper surface of the silicon substrate without interposing a space. The outer surface of the side wall portion of the fixed electrode plate is covered by a reinforcement film made of metal such as Au, Cr, and Pt.

主权项

1. A capacitive sensor comprising:
a substrate; a movable electrode plate arranged on an upper surface of the substrate; and a fixed electrode plate arranged on the upper surface of the substrate so as to cover the movable electrode plate, wherein a physical amount or change thereof is detected by a capacitance or a change thereof between the movable electrode plate and the fixed electrode plate, wherein the fixed electrode plate has a portion facing the upper surface of the substrate through a space, wherein the space is supported by a side wall portion arranged on an inner edge of a portion fixed to the upper surface of the substrate without interposing the space, wherein the fixed electrode plate comprises an outer peripheral part disposed at an outer periphery thereof, wherein the outer peripheral part comprises an inner peripheral edge and an outer peripheral edge, wherein a reinforcement film is formed on at least one part of the side wall portion along the inner peripheral edge of the outer peripheral part of the fixed electrode plate, wherein the reinforcement film is made of metal, wherein the reinforcement film is electrically insulated with both the movable electrode plate and the fixed electrode plate, and wherein the reinforcement film does not overlap an electrically conductive region of the movable electrode plate and an electrically conductive region of the fixed electrode plate.