Patent ID: 8067812
Filing Date: 2011-11-29
Classification: G01P

Abstract:
1. An acceleration sensor, comprising: a weight for displacing upon receiving acceleration; a base portion disposed around the weight apart from the weight, a beam having a first surface and a second surface opposite to the first surface, said beam having one end portion connected to the weight and the other end portion connected to the base portion, said beam including a thick portion, a thin portion having a thickness smaller than that of the thick portion in a non-deformed state of the beam, and a slope portion between the thick portion and the thin portion, said slope portion having a thickness changing gradually from that of the thick portion to that of the thin portion in the non-deformed state, said slope portion having a sloped surface only on the first surface so that the second surface has one single flat surface; and a piezo resistance element embedded in the thick portion, the slope portion, and the thin portion, wherein said thick portion includes a first thick portion, a second thick portion, and a third thick portion between the first thick portion and the second thick portion, said first thick portion and said second thick portion being situated at both the one end portion and the other end portion of the beam in a longitudinal direction thereof, said thin portion being situated between the first thick portion and the third thick portion, and the second thick portion and the third thick portion.