The Producing Process Of Micro-component By Electroless Plating Ni-P

Micro-Electro-Mechanical Systems (MEMS) is a newly developed technology in 1990s, an integration of such scientific fields as microelectronics, mechanics and optics. Compared with general Electro-Mechanical Systems, MEMS is advantageous not only because of its much smaller size, but also because it enjoys special laws that can hardly be explained by conventional theories. Its processing technology mainly includes LIGA, silicon's processing technology, micromachining technology, laser processing technology and so on. LIGA is adopted to produce micromechanical structures and parts by means of lithography that is used to produce electronic device. It thus integrates microelectronics and micro-mechanics and then provides an ideal way to fabricate MEMS.Having such advantages as higher precision, deeper structure, etc, LIGA has drawn much attention from many governments and enterprises and is now of more importance in fabricating MEMS. But its equipments are very expensive and the X-ray lithography mask fabricating is very complicated and difficult, so that the development of LIGA is badly defined. In order to reach a similar effect to that of LIGA, people have been trying to develop many quasi-LIGA technologies with the aim to promote the development of MEMS.Now, Micro-metal-components are deposited by electroforming in LIGA and quasi-LIGA processing. Compared with electroforming, electroless plating is of high-uniformity, needs no power-supply and causes no edge effect. If substituting electroless plating for electroforming, it can be made possible that processing can be simplified, costs saved, and property improved. However, little research can be found in this field nationwide.In this paper, the feasibility of this new technology was tentatively studied in several steps as follows: Firstly, we optimized the compounding and parameters of the electroless Ni-P plating, and thus improved the velocity of deposition and the properties of plating. Secondly, we studied the effect of heat treatment and analyzed the process of optimization. Thirdly, the process of electroless Ni-P plating was observed, and based on it a physical model of the process was presented. Meanwhile, we designed a process of quasi-LIGA processing by electroless plating, optimized the technological parameter, and fabricated a micro-gear of Ni-P alloy. The results of the whole experiment show that the quasi-LIGA processing by electroless plating is not only feasible, but also can meet most of the requirements in fabricating micro-components.