Research On Design And Experiment Of Silicon Piezoresistive Pressure Sensor

Sensor technology is an important branch in the field of MEMS, which is becoming more and more mature after decades of rapid development and has been widely used in all walks of life. The foreign sensor technology starts earlier and pays attention to innovation, so it is superior to the domestic sensor and occupies much of the market share. Due to the restriction of some factors such as technology, cost, and risk, the investment and level of many research institutions are low, and the development of the sensor technology is slow. The paper work is supported by national innovation fund projects.The task of the topic research is to design a sensor with high precision, good stability and mass production easily. In order to complete the design better and lay a solid foundation to the latter works, we should understand the principle of the pressure sensor and the existing workmanship. The main work of the paper is as follows:(1) The stress of the sensor was analyzed by the finite element analysis. On the basis of the small deformation, the size of the sensor structure including the thickness of the silicon wafer, cavity size and the thickness of the glass, etc. was calculated. The design of the sensor layout including the bridge road resistance size, position, thickness, etc. was carried on. The preliminary design work is completed.(2) The design of the production process of the pressure sensor and auxiliary processing production including photolithography and etching, anodic bonding, etc. were carried on. The sensor chips were grinded in the polishing machine and measured under the optical microscope to verify the reliability of the design.(3) The packaging work was finished. The influence that the parameters such as modulus of elasticity and thickness of the adhesives make is studied by the finite element analysis. The signals are lead out by the gold line(4) The construction of the test system is completed by using the equipment of the company, and the static data of the sensor was measured. Some key parameters were calculated, the sensor linearity and range performance is very good, and the sensitivity and zero drift. The sensor performance evaluation is completed.(5) The design of the signal conditioning circuit schematic diagram, and according to the principle of the chip and the actual requirements, the parameters of some components are optimized.(6) The compensation parameters were written to the memory chips of the regulating chips by the existing control program. The precision of the measurement meet the requirements completely. The temperature compensation and signal processing for the sensor were achieved.