Patent ID: 8056421
Filing Date: 2011-11-15
Classification: G01B,G01L

Abstract:
1. A mechanical quantity measuring apparatus having a strain detector formed on a principal surface of a single crystal semiconductor substrate for detecting a strain and bonded to or buried in an object to be measured to measure a strain, comprising: an amplifier circuit disposed on the principal surface of the single crystal semiconductor substrate for amplifying a signal of the strain detector, and a communication control unit for transmitting a signal amplified by the amplifier circuit, the communication control unit disposed on the principal surface of the single crystal semiconductor substrate toward a periphery of the mechanical quantity measuring apparatus, wherein the strain detector includes a Wheatstone bridge circuit disposed on the principal surface, the Wheatstone bridge circuit comprising a pair of sensor resistor layers and a pair of dummy resistors, wherein a resistance value of each sensor resistor layer being equal to a resistance value of each dummy resistor, a surface of the single crystal semiconductor substrate opposite to the principal surface on which the strain detector has been formed being flat and adhered to a surface of the object, wherein the strain detector is located closer to a central part of the principal surface of the single crystal semiconductor substrate than both the amplifying circuit and the communication control unit, wherein a longitudinal direction of the pair of sensor resistor layers is parallel to a strain measurement direction, and a longitudinal direction of the pair of dummy resistors is substantially at 90° or 45° to the strain direction.