电磁压制与烧结工艺对无镉中温银基钎料性能的影响

发布时间：2018-03-12 17:20

本文选题：无镉银基钎料　切入点：粉末冶金　出处：《武汉理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：无铅无镉钎焊材料是全球性的环保发展需求,在计算机、汽车、航空航天等领域中的微电子产品封装和一些特殊材料的焊接方面具有广阔应用前景。如何高效率低成本地制造性能优良的环保钎料一直是企业界和学术界致力解决的关键问题。近年来,用电磁压制方法制备环保钎焊材料薄片是一种新的探索,可有效回避传统方法因熔炼、凝固产生大量脆性相导致后续成形加工难以进行的瓶颈问题,且压制模具可直接根据封装产品形状、尺寸进行设计,压制成形的钎料经烧结后即可直接用于钎焊封装工序,在满足微电子封装用钎焊材料多样性需求的同时,也简化了后续工艺、降低了生产成本。本文将电磁成形与粉末冶金技术结合,充分利用各自的特点与优势,采用电磁压制方法制备微电子封装所用的环保钎焊材料,不仅能够较好地解决环保钎料难以加工成形的难题,还能通过提高压坯压制密度和致密均匀性来进一步改善钎料最终的焊接性能。探索了一种优质高效的环保钎料制备新技术,对推进微电子封装产业的发展、丰富难成形材料制备加工理论与方法具有重要意义和经济价值。本文采用理论分析、工艺实验和微观分析的方法对粉末电磁压制压坯和液相烧结体进行了系统的研究。以钎料性能和环境保护作为研究目的,通过分析各元素对钎料性能的影响,确定BAg44Cu28Zn25Sn3无镉中温银基钎料作为研究对象,在低电压电磁脉冲成形机上进行电磁压制,通过观察不同放电电压下压坯的断口形貌,采用控制变量法计算不同放电电压以及储能电容下压坯的密度,分析多金属混合粉料高速压制成形的机理与规律,有针对性地构建高速率压型方程,为多金属混合粉料高速压制过程的模拟分析提供模型与方法。结果显示随着放电电压的增大,电磁脉冲力不断增大,压坯内的粉末颗粒结合越紧密颗粒变形越小,压坯致密性越好;放电电容越大,电磁脉冲力增大的同时也延长了压制时间,致使压坯密度出现先增大后减小的趋势。电磁压制后的压坯在SX2-4-10箱式节能电阻炉中采用氩气的保护气氛进行液相烧结,以烧结温度和烧结时间为变量,结合烧结体密度计算、显微硬度测量、显微组织及断口形貌分析、EPMA面分布分析、XRD物相测试及相图分析,讨论了烧结工艺参数对烧结体性能的影响,为合理制定烧结工艺提供了参考。结果显示烧结温度增加保温时间减小会使烧结体内孔洞变小变少,显微组织细化,元素分布均匀,组成成分和内部组织越接近于完全合金化的烧结体,性能越好。
[Abstract]:Cadmium free lead-free soldering materials is a global environmental development needs, in the computer, automobile, has the broad application prospect of welding microelectronics packaging in aerospace field and some special materials. How to high efficiency and low cost of environmental protection solder has excellent local manufacturing performance is a key problem in business and academic circles in recent years committed to solve. With the preparation method of electromagnetic compaction, environmental protection brazing material sheet is a kind of new exploration, can effectively avoid the traditional method for melting and solidification to produce a large number of brittle phase leads to subsequent forming the bottle neck problem processing difficult, and pressing directly according to the package of product shape, size design, forming the solder after sintering. Directly used for brazing packaging process in microelectronic packaging with a brazing material demand diversity at the same time, it simplifies the follow-up process, reducing the cost of production. The electromagnetic forming. This paper combined with powder metallurgy technology, make full use of their own characteristics and advantages, environmental protection brazing material by electromagnetic used in microelectronic packaging by pressing method system, not only can solve the environmental problems difficult to solder forming, but also through high density and tight pressing provided to further improve the uniformity of solder end the welding performance are discussed. A kind of high quality environmental protection solder preparation technology, to promote the development of microelectronic packaging industry, rich hard forming has important significance and economic value of materials preparation and processing theory and method. This paper uses the method of theoretical analysis, experiments and microscopic analysis was carried out on the blank and pressing the liquid phase sintering of powder. The electromagnetic properties of solder joints and environmental protection as the research objective, through the analysis of the influence of various elements on the properties of BAg44Cu solder, determine 28Zn25Sn3 cadmium free silver filler metal temperature as the research object, in the low voltage electromagnetic pulse electromagnetic compaction machine. The fracture morphology was observed by different discharge voltage compacts, using control variable method to calculate different discharge voltage and capacitor under the compact density of metal powder mixture mechanism and rule of high speed press forming, targeted to build high rate pressure equation, model and method for providing multi metal powder mixture simulation analysis of high speed pressing process. The results showed that with the increase of discharge voltage, electromagnetic pulse force increasing, pressure of powder particles in blank with more closely particle deformation is small, compact and compact the better; discharge capacity increases, while the increase of electromagnetic pulse force also extended the pressing time, resulting in the emergence of compact density first increased and then decreased. The compact electromagnetic compaction after SX2-4-10 box section Can the resistance furnace with protective atmosphere of argon by liquid phase sintering, the sintering temperature and sintering time is variable with the sintered body density calculation, microhardness measurement, microstructure analysis and fracture morphology analysis, surface analysis of distribution of EPMA, XRD phase test and phase diagram, the effects of sintering parameters on the properties of sintered body are discussed and provide a reference for establishing reasonable sintering process. The results showed that the increasing of sintering temperature holding time reduces the sintering body cavity becomes smaller and less, microstructure, element distribution, composition and internal organization is closer to the sintered body to completely alloyed performance better.

【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG425

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