Micro Pressure Sensor Design And Technology

Micro pressure sensor is one of the most widely used products in MEMS. With the development of science and technology, increasing demands on the new generation sensors.In this paper, the micro pressure sensor with 20 Kpa full scale span. It focuses on structural design, modeling and simulation to enhance the sensitivity. Another important aspect of the paper is process design and the sensor is fabricated by the micro machining technology. In addition, using ANSYS software to simulate the sensor and get some rules of the sensor property.Firstly, based on basic knowledge of micro pressure sensors, piezoresistive effect, small deflection theory, Wheatstone bridge and some other related knowledge, the sensor's structure and dimensions are determined. Square and circular patch on the stress were compared in the same sizes and pressure, the result shows that the square patch's mechanical property is better. The simulation result of the pressure distribution by means of ANSYS shows best location of the resistor. Collection different peak stress under different pressure, obtain the output value. Application this method to design the sensor has a greater output. Secondly, the photosensitive masks of sensor chip designed according to the above parameters by theoretical calculated and a process flow planed according to micro machining processes. At last, on the basis of the process flow to make the sensor chip successfully, by analyzing experimental results obtained the factors that affect the quality of process.The experimental results which prove the feasibility of the process flow. Compared the simulation result with the theoretical result, get the same output value which also prove the correctness of the design.