Patent ID: 6502462
Filing Date: 2003-01-07
Classification: G01P

Abstract:
A capacitance type dynamic quantity sensor comprising:a support substrate; a displacement portion composed of a first beam connected to the support substrate, a second beam provided separately from and in parallel with the first beam, and a beam connection part connecting the first beam and the second beam at ends thereof, the first beam, the second beam and the beam connection part forming a frame shape; a movable electrode connected to the second beam and suspended above the support substrate; a fixed electrode fixed to the support substrate and facing the movable electrode defining an interval therebetween; and first and second electrode pads provided on the support substrate to be electrically connected to an outside circuit by wire bonding for electrically connecting the movable electrode and the fixed electrode to the outside circuit, wherein: the first and second beams of the displacement portion perform detecting vibration with the beam connection part working as a fixed end in a direction perpendicular to a longitudinal direction of the displacement portion, when a dynamic quantity is applied to the displacement portion, so that the movable electrode is displaced to detect the dynamic quantity based on a change in capacitance between the movable electrode and the fixed electrode; the first and second beams can perform flexural vibration to bend in an identical direction with the beam connection part working as a free end, and with connection parts between the first beam and the support substrate and between the second beam and the movable electrode working as a fixed end; and a shape of the beam connection part is adjusted so that a natural frequency of the displacement portion at the flexural vibration is different from a frequency of vibration that is applied to the displacement portion by the wire bonding.