Semiconductor dynamical quantity sensor device having electrodes in Rahmen structure
First Claim
1. A semiconductor sensor device comprising:
- a semiconductor substrate;
a movable unit supported on the semiconductor substrate, and having a weight portion movable in response to a dynamical force exerted thereon and a movable electrode formed integrally with the weight portion and having a detection surface; and
a fixed electrode cantilevered on the semiconductor substrate and having a detection surface facing the detection surface of the movable electrode,wherein the movable electrode and the fixed electrode are constructed in Rahmen structure which includes a series of a plurality of rectangular frames.
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Accused Products
Abstract
A semiconductor accelerometer device is formed on an SOI substrate by micro-machining. A movable unit is supported at both ends, and a weight portion is movable in response to acceleration exerted in the detection direction. A movable electrode is formed in a comb shape integrally with the weight portion. A pair of fixed electrodes in a comb shape are cantilevered and interleaved with the movable electrode to face the movable electrode. A plurality of through holes is provided in the electrodes so that the electrodes have Rahmen structure which is a series of rectangular frames. This structure reduces the weight of each electrode while increasing the strength against twist force. The electrodes are less likely from breaking in response to an acceleration exerted in a direction perpendicular to the normal detection direction because of reduced weight.
101 Citations
23 Claims
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1. A semiconductor sensor device comprising:
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a semiconductor substrate; a movable unit supported on the semiconductor substrate, and having a weight portion movable in response to a dynamical force exerted thereon and a movable electrode formed integrally with the weight portion and having a detection surface; and a fixed electrode cantilevered on the semiconductor substrate and having a detection surface facing the detection surface of the movable electrode, wherein the movable electrode and the fixed electrode are constructed in Rahmen structure which includes a series of a plurality of rectangular frames. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A semiconductor sensor device comprising:
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a semiconductor substrate; a fixed electrode fixedly supported on the semiconductor substrate at one end and forming a parasitic capacitor with the semiconductor substrate; and a movable electrode supported lovably on the semiconductor substrate and forming a variable capacitor with the fixed electrode, wherein the fixed electrode has at least one groove which extends from the semiconductor substrate, and wherein said fixed electrode and said movable electrode are constructed in Rahnen structure.
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22. A semiconductor sensor device comprising:
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a semiconductor substrate; a fixed electrode fixedly supported on the semiconductor substrate at one end and forming a parasific capacitor with the semiconductor substrate; and a movable electrode supported movably on the semiconductor substrate and forming a variable capacitor with the fixed electrode, wherein the fixed electrode has at least one groove which extends from the semiconductor substrate, and wherein each of the fixed electrode and the movable electrode has a plurality of through holes to provide a series connection of rectangular frames which corresponds to Rahmen structure.
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23. A semiconductor sensor device comprising:
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a semiconductor substrate; a movable unit supported on the semiconductor substrate, and having a weight portion movable in response to a dynamical force exerted thereon and a movable electrode formed integrally with the weight portion and having a detection surface; and a fixed electrode cantilevered on the semiconductor substrate and having a detection surface facing the detection surface of the movable electrode, wherein each of the movable electrode and the fixed electrode having a plurality of through holes arranged in a direction in which the movable electrode and the fixed electrode extend, and wherein said fixed electrode and said movable electrode are constructed in Rahmen structure.
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Specification