Research On Key Technologies Of Integrated Microfabrication Based On Electrical Processing

Currently,the miniaturization of products has become one of the most urgent demands in the area of advance technology due to its special application in some certain industries.Yet the pivotal bottleneck hindering the design,manufacture and implementation of miniature products is the fabrication crux of their key units.The main reason of this phenomenon is not the lack of micro machining technology,it's because many tricky problems still remain to be solved when it comes to the fabrication of integral micro mechanism and system.And one of the many problems is that,even though the micro parts could be fabricated precisely,their assembly into components and systems are not easy to accomplish.In terms of the above situation,a technology concept of Manufacture Integrating Subtractive-method and Additive-method(MISA)is introduced.And a MISA-kind manufacturing technology based on electro-machining,named Manufacture Integrating Galvanoplasty and Electrical Discharge(MIGED),is proposed to realize the integrated manufacture of micro mechanisms.Specifically,for a target micro mechanism,first its 3D model is sliced into several layers.In each layer,structure material and sacrificial material are deposited using micro galvanoplasty as an additive-method and their filling texture are realized by micro EDM milling as a subtractive-method.At the end of each layer,their surface are planarized using block electrical discharge grinding(BEDG).By repeating these procedures,materials can be stacked layer by layer.After all the layers are generated,the sacrificial material is removed and the machining target can be released.MIGED experimental platform is built on an EDM machine tool.In order to solve the fluid switching problem,opposite to conventional machining layout,the workpiece is clamped on the spindle and its undersurface is regarded as the machining surface.The processing tools are fixed to the workbench and with its movement,switching of procedures can be realized easily.Further researches concerning the keypoint in MIGED are conducted as follows:Since the tool in micro EDM milling is reclamped,a compensation method dealing with the accuracy lost caused by tool tilt angle is proposed;A helical-like feeding track of micro EDM milling is devised to avoid the collide between tool and workpiece thereby the machining accuracy could be improved;low tool wear or even its exceeding compensation phenomenon is discovered and analyzed in reversed micro EDM milling;Preliminary researches on the processing laws of reversed micro galvanoplasty and BEDG are carried out.Lastly,entire MIGED manufacturing experiments are taken on the MIGED platform and two micro bridges with the height of 100?m,the width of 28?m and 83?m and the length of 38?m and 377?m,respectively,are fabricated using MIGED.Thus,MIGED is affirmed of capability of 3D integral fabrication.