Capacitance Micro-differential Pressure Servo Sensor Design And Production

Micromachined capacitive difference pressure sensors based on MEMStechnology are very important sensors Combining with the IC, the sensorscan be made together with its interface circuit on a same siliconsubstrate As result, the cost can be lowered while the sensitivity andresolution can be improved The mlcromachined capacitive differencepressure sensors are wildly used in pressure controiling system, suchas air conditioner and pressure detecting instrumentsIn this paper, a literature review of the MEMS technology andcapacitive pressure sensors were comprehensively surveyed in chapter oneAnd the prospect of MEMS technology and micromachined capacitivepressure sensors were studiedIn chapter two, we presented a new capacitive difference pressuresensor Then the principle of sensor and the structure characters werestudied in detail. Because the sensor can be fabricated with one of twodifference structures (C─type or E─type), We used two difference modelsto explain Some structure parameters were obtained by Finite ElementMethod In order to calculate the characters of E─type structure rapidly,we offered a nonlinear model to simulate the E─type structureapproximatelyIn chapter three, we discussed the principle of etch─stop process,which is the key step in whole procedure. The etch─stop process includesboron diffuse and KOH etch process By using this process, we havefabricated several difference microstructures, such as two kinds of lightgrating diaphragm As result, we summarized the peculiarities of processand fixed on the main parameters in processIn chapter four, we finished the capacitive difference pressuresensor by utilizing the previous results The whole process werediscussed in detailIn chapter five, we detected the new capacitive difference pressuresensors The sensors can detect a very small difference pressure rangefrom 0 Pa to 100 Pa...