US 2006/0220662 A1 · Physical quantity sensor

Abstract

A highly accurate physical quantity sensor which can ensure reliability in strength and reduce resistance changes caused by stresses. Assuming, with respect to stress σ imposed on a substrate in a predetermined direction (e.g., direction in which maximum stress is imposed), a parallel direction to be a horizontal direction and a perpendicular direction to be a vertical direction, each of resistors of the sensor has a horizontal resistance component Rl and a vertical resistance component Rt. When a ratio of a piezoresistance coefficient πl of the horizontal resistance component Rl, which is provided when the stress imposed on the substrate is applied to the horizontal resistance component Rl, to a piezoresistance coefficient πt of the vertical resistance component Rt, which is provided when the stress is applied to the vertical resistance component Rt, is πl:πt=−n:1 (n:integer), a resistance value ratio of the vertical resistance component Rt to the horizontal resistance component Rl is set substantially equal to the ratio of the piezoresistance coefficient πl to πt.

Claims8

Dependent claims

A physical quantity sensor including a resistor for measuring a physical quantity, said resistor being formed on a substrate in a pattern of strips,

wherein assuming, with respect to stress imposed on said substrate in a predetermined direction, a parallel direction to be a horizontal direction and a perpendicular direction to be a vertical direction, said resistor has a horizontal resistance component Rl and a vertical resistance component Rt, and
when a ratio of a piezoresistance coefficient πt of the vertical resistance component Rt, which is provided when the stress imposed on said substrate in the predetermined direction is applied to the vertical resistance component Rt, to a piezoresistance coefficient πl of the horizontal resistance component Rl, which is provided when the stress imposed on said substrate in the predetermined direction is applied to the horizontal resistance component Rl, is πt/πl=−1/n (n:
integer), a resistance value ratio of the horizontal resistance component Rl to the vertical resistance component Rt is set substantially equal to an absolute value of the ratio of the piezoresistance coefficient πt to πl (Rl/Rt≈|πt/πl|).

Dependencies are inferred from the claim text.

Physical quantity sensor

Life of this patent

Physical quantity sensor

Life of this patent

Abstract

Claims8