Patent ID: 7287433

Claim:
A pressure sensor for detecting a pressure and for outputting a signal based on the piezoresistance effect of a sensor chip comprising: a substrate having the sensor chip on one side and a concave portion on another side, wherein an area of sensor ship disposition on the one side of the substrate corresponds to an area of the concave portion on the another side of the substrate to form a thin portion; a piezo-resistor in the sensor chip for outputting a sensor signal that proportionally represents an applied pressure; a pedestal being attached to the substrate and having a through hole for introducing the pressure to the sensor chip on the thin portion; and a gel material filled in the concave portion and the through hole for protecting the sensor chip, wherein the pedestal made of glass is attached to the substrate by anodic bonding, and a ratio of a diameter of the through hole to a thickness of the pedestal is substantially within a range of 1 to 3.