| 摘要 |
PURPOSE:To accurately detect required acceleration by forming each piezo resistor so that the ratio of its length to width is large, allowing each longitudinal direction to intersect with the extending direction of a deflection part at right angles and arranging respective piezo resistors on both the weight part and frame part sides. CONSTITUTION:The semiconductor acceleration sensor is constituted of the weight part 21 formed on the center part, elastically deformable deflection parts 22a to 22d and the piezo resistors R1 to R4 formed in parallel with respective deflection parts 22a to 22d and constituting two wheatstone bridge circuits by applying anisotropic etching work to a semiconductor substrate 20. Respective piezo resistor R1 to R4 are formed on both th weight part and frame part sides so that the ratio of length to width is large and respective longitidunal directions intersect with the extending directions of respective deflection parts 22a to 22d at right angles. When the weight part 21 is deformed by receiving acceleration, the stress directions of respective deflection parts 22a to 22d are mutually reversed n the weight part side and the frame part side and the codes of resistance changes of respective resistors R1 to R4 are reversed. |
