Application No./Patent No.: 2018102536609 Application date: March 26, 2018.
Inventor/Designer: Li Kai, Peng Zhihui.
A high-range capacitive micro-pressure sensor with ring contact. It comprises a substrate, a fixed electrode located on the substrate, a thin film and a moving electrode located on the thin film. In a chamber formed by closing the substrate and the thin film, the substrate is provided with a stop ring. In a non-working state, there is a gap between the stop ring and the thin film. In a normal working state, the thin film only contacts the stop ring except for the initial stage of the measuring range, and the thin film has the characteristic of stage-like unequal thickness. According to the invention, a stop ring is used to replace the insulating layer in the traditional contact mode capacitive micro-pressure sensor, so that too low sensitivity caused by capacitance saturation and hysteresis error caused by friction force and van der Waals force are suppressed; and an unequal-thickness stepped film is used to replace an equal-thickness film in the traditional contact or non-contact mode micro-pressure sensor, which is beneficial to reducing bending stress.
