| The acceleration sensor is the most widely used sensors.The three-axis micro-acceleration sensor can be used to measure the X,Y axis and Z axis,and has a variety of applications in many fields such as weapons,navigation,safety,automation,etc.,and it has great influences on national security and economic construction.In order to improve the shortcomings of the existing three-axis accelerometer detection method,this research group proposed a new method of single-mass sensitive to three-axis acceleration signal produced by micro-mechanical process.Micro-bridge resonator detects the X/Y-axis acceleration signal.The Z-axis acceleration is measured on the base of the force equalization capacitance detection mechanism.The resonant beam is located on the upper surface of the substrate.The center of the support beam is in the same plane as the center of gravity of the mass.The mask and the maskless etching are used to realize the simultaneous formation of the support beam and the resonant beam.The sensor has a simple structure and is expected to have a low cross-axis sensitivity.According to the division of labor of the research group,the following research work is carried out in this paper:(1)A silicon nitride film resistant to KOH corrosion was produced by optimizing the deposition process of PECVD silicon nitride film,and the effective protection of polysilicon resistance during masking and masking etching was realized.The silicon nitride film can be used not only for the wet etching masking layer of polysilicon resistance,but also for other wet etching masking layers.(2)A three-axis acceleration sensor package is proposed.The upper and lower plates of the acceleration sensor were designed and fabricated.It is proposed to use gold-amorphous eutectic bonding to realize the bonding between the upper plate,the main chip and the lower plate.The successful research of the above process has laid a good foundation for the development of three-axis acceleration sensor. |
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