| 摘要 |
PROBLEM TO BE SOLVED: To reduce the error in the frequency of a natural oscillation mode even when variation exists in the thickness of wafers. SOLUTION: The oscillation body apparatus has a supporting part which rockably supports a movable part around a torsion axis, wherein the cross section of the supporting part perpendicular to the torsion axis has X-shape, wherein the distance L1 between the respective bottoms of the concave parts which are formed on the upper and the lower faces of the X-shape, the distance L2 between the respective bottoms of the concave parts which are formed on the side faces of the X-shape, and the variation rateαi of the moment of inertia around the torsion axis of the movable part according to the variation in the thickness t of a supporting substrate satisfy the relation, L1/L2=C1×ExpäC2×(αi+C3)}+C4×αi+C5, where C1, C2, C3, C4 and C5 are given by C1=5.0×10<SP>Λ</SP>-1 C2=-4.4, C3=4.6×10<SP>Λ</SP>-1 and C4=-6.0×10<SP>Λ</SP>-1 respectively, and the relation 1.5<C5<1.7 is satisfied. COPYRIGHT: (C)2009,JPO&INPIT
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