| Lead-free and Cadmium-free brazing material meets the demand of global environmental protection development. It owns a broad application prospect in the fields of computer, automotive, aerospace etc, such as microelectronics products packaging and welding aspect of some special materials. How to make green lead material with a high efficiency and with a low price has been a key problem for the industry and academia to deal with. In recent years, the electromagnetic suppression method for the preparation of environmental brazing materials chip is a new exploration, which can effectively avoid the brittle phase leading to the bottleneck problem of subsequent forming because of melting and solidification of traditional methods, and pressing moulds can be designed directly according to the packaging products shape, size; pressed and formed lead material after sintering can be directly used for brazing encapsulation process; meeting the demand of the brazing material diversity of microelectronics packaging, at the same time, it also simplifies the subsequent process and reduces the production cost. This paper combines with electromagnetic forming and powder metallurgy technology and adopts magnetic suppression method to make environmental brazing materials used in the usage of microelectronic packaging. This method can make full use of their own characteristics and advantages, and it can not only well solve the problem of forming hard of environmental protection material of lead, but also can further improve lead welding performance by improving the compact compressed density and the density uniformity, which explores a new technology of lead environmental preparation within a qualified and an efficient way. It will have great significance and economic value for promoting the development of microelectronics packaging industry and enriching the processing theory of difficult-forming material preparation.Based on the theoretical analysis, experiment technology and micro analysis method, this paper makes a systematic study for power electromagnetic suppress compact and liquid phase sinters. Regarding lead performance and environmental protection as the research objective, through the analysis of the effect of various elements on the properties of lead, BAg44Cu28Zn25Sn3(low silver-containing cadmium-free intermediate temperature brazing filler metal) is determined as the object of study. The metal is on the low voltage electromagnetic pulse shaping machine for electromagnetic pressing, and by observing fracture patterns under different discharge voltage, and adopting control variable method to analyze and calculate the compacting density under different discharge voltages and different capacitors, it reveals the mechanism and regularity of various mixed metal powder forming within a high-speed. It is targeted to construct high speed pressure equation which provides models and methods for the simulation analysis of various mixed metal powder compacting process. The result shows that with the increasing of discharge voltage, the greater the electromagnetic pulse force, and compact powder particle is more closely, then the deformation of the particle is smaller and compacting density is better; when the discharge capacity is larger, the increasing electromagnetic pulse force also extends the pressing time so as to make the compacting density appear the tendency of from increase to decrease.The compact after Electromagnetic suppression in SX2-4-10 box-type energy-saving electric resistance furnace adopts argon protective atmosphere to process the liquid phase sintering; Regarding the sintering temperature and sintering time as variables, and combined with the calculation of the density of sintered body, micro-hardness measurement and SEM observation of microstructure, fracture patterns, the distribution analysis of EPMA element, XRD phase text and diagram analysis, it reveals the influence of the sintering process parameters on the properties of sintered body, which provides reference for choosing appropriate sintering process. The result shows that the sintering temperature increasing, and holding time reducing will make the holes of sintered body become smaller and less, the microstructure refine, elements distributions uniform; the composition and internal organization are closer to full alloying of sintered body, the better is the performance. |
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