The Development Of The Silicon Capacitance Different Pressure Sensor

The silicon capacitance different pressure sensor has been developed successfully overseas and not at home. It is confirmed the nation "FIFTEEN" task in order to make it by ourselves and satisfy with the market demand.A few design projects on the silicon capacitance different pressure sensor are mentioned in the paper. After the existing processing and technology level are reviewed and that which of these design projects is easier to this sensor industrialization are considered, a optimal design project which can accord with the existing processing, is easier to industrialize and can be compatible with manufacture of other products is confirmed.The silicon capacitance different pressure sensor was developed in the Shenyang Institute of Instrumentation Technology with some kinds of the MEMS processing. The principle, virtue and defect, the effect of condition and flow of these MEMS processing are stated in detail in the paper. For example, the silicon is etched anisotropically in the KOH solution, the lucent Al film is made with the magnetron sputtering system, the pressure hole is drilled by the supersonic stiletto machine and the silicon and the glass are bonded with electrostatic bonding setup. Some samples were also tested there, and as a result their repetition, come-and-go difference and lag performance can satisfy with the demand, but the stabilization performance is a little bad and there exist the time excursion. After the mass information was refered to and the much experiment was performed, the root of the bad stabilization performance was found and it can be solved with the existing processing. Now the stabilization performance has been advanced and the silicon capacitance different pressure sensor has been developed successfully.There are a great deal of data, curve, picture and some correlative photographs in the paper, and these are reliable basis of the developed sensor.In addition, the software of ANSYS is used to analyze the square silicon island-diaphragm displacement under certain pressure. As a result, littler the size of silicon island-diaphragm is, better the island can move in parallel. But the size of silicon island-diaphragm is affected withother sizes such as the capacitance relative area and the gross size of sensor and so on. These are academic basis of the developed sensor.