Rotating body dynamic quantity measuring device and system
AssigneeHitachi, Ltd.
InventorsHiroyuki Ohta, Takashi Sumigawa
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Abstract
A single crystal semiconductor including a Wheatstone bridge circuit formed of an impurity diffusion layer whose longitudinal direction is aligned with a particular crystal orientation is connected to a rotating body. A rotating body dynamic quantity measuring device and a system using the measuring device are fatigue- and corrosion-resistant because of the single crystal semiconductor used and are not easily affected by temperature variations because of the bridge circuit considering a single crystal anisotropy.
Claims1
A rotating body having a dynamic quantity measuring device, said dynamic quantity measuring device comprising:
- a Wheatstone bridge circuit having strain sensors and dummy resistors on a [001] surface of a single crystal silicon substrate, wherein
- said strain sensors each comprising an area having n type impurity diffusion layer in the silicon substrate and a longitudinal direction thereof is the same direction as a <100> direction of the silicon substrate, said dummy resistors each comprising an area having n type impurity diffusion layer in the silicon substrate and a longitudinal direction thereof is at 90 degrees to the longitudinal direction of said strain sensor, and
- a <110> crystal axis of said single crystal silicon substrate substantially matches the circumferential direction of said rotating body.
Dependencies are inferred from the claim text.