Patent ID: 8096189

Claim:
A physical quantity sensor, comprising: two substrates; and a movable electrode that is disposed between the two substrates and is bonded to the two substrates, wherein the movable electrode is provided with an elastically deformable diaphragm, at least one of the two substrates is an electrode substrate having one or more detection electrodes on a surface opposite to the diaphragm to detect a change in capacitance between the diaphragm and the detection electrode, and wherein, in a range between a room temperature and a bonding temperature when the two substrates are bonded to the movable electrode, coefficients of thermal expansion of the two substrates are smaller than a coefficient of thermal expansion of the movable electrode, and, the two substrates are a first substrate and a second substrate having different coefficients of thermal expansion with each other in a temperature range where the physical quantity sensor is used, the coefficient of thermal expansion of the movable electrode being between the coefficients of thermal expansion of the first substrate and the second substrate in a temperature range where the physical quantity sensor is used.