Analysis of abnormal output of pressure sensor based on piezo-resistive effect of monocrystalline silicon at low air pressure
A certain type of piezoresistive pressure sensor exhibits a higher output in the low-air pressure section in actual engineering.Considering the structural composition of this sensor,a fault tree causing this phenomenon is established.Exclusions are carried out one by one based on the fault tree by means of appearance inspection,insulation resistor test,and replacement of possible faulty components.It is analyzed determined that the fault occurrs in the pressure core.Further,the core is analyzed through methods such as microscope and the hand-twisting method.It is determined that the presence of bubbles in the silicone oil lead to the higher output of the sensor in the low-pressure section.The three types of relationships between the pressure in the bubbles and the input pressure are analyzed.The failure mechanism of the higher output in the low-pressure section when the input pressure is less than the internal pressure of the bubbles is obtained.The fault phenomenon is reproduced by encapsulating the pressure core in an air environment.It is suggested to increase the low temperature and low-air pressure screening test on the pressure core.
万方数据
维普
