Study On Micro Milling Technology Of Sensitive Components Encapsulation Glass

As the functional sensitive component micro sensor is being widely used in thefields of military industry, aerospace, higher performance requirements are needed.Electronic glass is the main packaging material of sensitive components, but the thickerand uneven glass layer may reduce the performances of inner sensitive components suchas the dynamic response after encapsulation. As a consequence, the performance ofmicro sensor would be affected. Although the changing of encapsulation layer thicknessand contour shape by subsequent processing may improve the performance of microsensor, the inner sensitive components and external irregular encapsulation layer shapecould limit the use of lots of processing methods. Combined with the actual needs andthe different processing methods, this paper puts forward the method of micro millingwhich is used for ductile regime machining of electronic glass. The theoretical analysis,numerical simulation and experimental validation are combined to study the mechanicalproperties and processing characteristics of electronic glass material. The ductile regimecutting mechanism and realization conditions of electronic glass material were analyzed,the trend of cutting force was predicted and the influence of processing parameters onductile regime micro-milling was explored. The results would have the importanttheoretical significance and practical value on obtaining desired thickness and contourshape of electronic glass encapsulation layer and improving the performance of microsensor.Based on considering the repeatedly cutting conditions in actual processing, thebasic mechanical performance parameters of electronic glass material were obtained byVickers-indentation and Nano-indentation experiments, the stress-strain curve wascalculated and drew, the critical conditions for crack initiation in the process of verticalloading and the influence of different loading times on the material elastic-plasticresponse rates and brittle-to-ductile transition were studied, the ductile regime cuttingmechanism of electronic glass material and the stable cutting conditions were analyzedand calculated. The cutting force model of the micro end milling was established andthe cutting force parameters were fitted in micro milling electronic glass, the rationalityof the model was verified by experiments and the trend of cutting force was predicted.The3D simulation model of micro milling electronic glass was built by finiteelement method to study the influence of spindle speed, feed per tooth and axial cuttingdepth which were within the selected scope of the milling parameters on the ductileregime micro milling process of electronic glass material, then the parameter ranges ofductile regime micro milling electronic glass were analyzed and forecasted. On the basisof the forecast results, the cutting tools with different materials were used in explorationtests and verification experiments to further reduce the parameter ranges of ductile regime micro milling electronic glass and determine the scope of the parameters byexperiments. Finally, the ductile regime micro milling of electronic glass wasimplemented, the thickness of the peripheral encapsulation glass layer of micro sensorwas reduced and the high quality machining surface without crack was obtained. Inaddition, the tool wear condition and the matters needing attention during theexperiments were discussed in this paper.