Technology Research On SIMOX High Temperature Pressure Transducer

High temperature pressure transducers refer to those transducers the working temperature of which is higher than 125 . Among all the pressure transducers, the high temperature pressure transducer were paid high attention to because of their excellent working performance at high temperature. They present not only one of the major fields in transducer R&D, but also one of the advanced technologies that every government is doing its best to master.Based on the SIMOX to design the structure and process of high temperature pressure transducer , the manufacturing process is presented. Semiconductor planar process is used to fabricate pressure sensor, and anisotropic etching technology is used in chip making. The chip is mounted to the fixed ring through electrostatic bonding, then the gold paste is used to glue the unit to the alloy of Fe-Co-Ni base. Thus the high temperature pressure sensor is made.The rectangular diaphragm is used in the transducer chip. In the planar process, the accuracy of the resistance fabrication method-anisotropic etching is discussed. KOH solution is used as etchant, three approaches to achieve the uniformity of the film are introduced. The capability to endure high temperature shock, characterstics' measurement between high and low temperature, and compensation of temperature drift are made to the product. The transducer is combined with low thermal sensitivity drift and thermal zero drift, good linearity, and almost the same slope, all of these make it easier to compensate the transducer.The SIMOX high temperature pressure transducer is provided with the follow good characteristics: sample structure, compatible with semiconductor process, fit to mass producing.Through the testing, the range of the transducer is 0~lMpa, accuracy is 0.5%,working temperature is -65-250, power consumption is below 8mW, full scale output is not less than 60mV, current is 2mA, the outline size is less than 19 X 30, and it has the ability to endure instantaneous 1000 high temperature shock.