Capacitive sensor
First Claim
1. A capacitive sensor for sensing pressure, comprising:
- a first substrate having a thin portion capable of being displaced by external force and wherein said thin portion serves as a movable electrode;
a second substrate having a fixed electrode provided on a position facing said movable electrode, a gap being formed between said movable electrode and said fixed electrode; and
a fixing member connected between the first and second substrate for fixing the center of said thin portion so as to prevent the center of said thin portion from being displaced.
1 Assignment
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Accused Products
Abstract
To provide a capacitive sensor which produces a sensor output excellent in linearity. The capacitive sensor comprises a first semiconductor substrate and a second substrate. The first semiconductor substrate is formed with a frame portion and a diaphragm portion serving as a movable electrode, and bonded with the second substrate at the upper surface of the frame portion by anodic bonding. The second substrate is provided with a fixed electrode on a surface facing the diaphragm portion. A fixing projection is provided on a center of the diaphragm portion and is fixed to the second substrate through a hole of the fixed electrode. When external force is applied to the sensor, the diaphragm portion displaces upward and/or downward. The external force is detected based on change of electrostatic capacitance. Since the center of the diaphragm portion is fixed by the fixing projection, the maximum displacement region of the diaphragm portion forms a ring, resulting in enhancement of linearity of the sensor output.
65 Citations
11 Claims
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1. A capacitive sensor for sensing pressure, comprising:
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a first substrate having a thin portion capable of being displaced by external force and wherein said thin portion serves as a movable electrode; a second substrate having a fixed electrode provided on a position facing said movable electrode, a gap being formed between said movable electrode and said fixed electrode; and a fixing member connected between the first and second substrate for fixing the center of said thin portion so as to prevent the center of said thin portion from being displaced. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification