超细钨粉及碳化钨粉制备工艺研究

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上海交通大学 硕士学位论文 超细钨粉及碳化钨粉制备工艺研究 姓名:王岗 申请学位级别:硕士 专业:微电子学与固体电子学 指导教师:王庆康
20090101
上海交通大学硕士学位论文
摘要
超细钨粉及碳化钨粉制备工艺研究
来自百度文库摘要
难熔金属钨合金具有一系列优良的物理性能,在包括半导体制造业 在内的诸多产业中有着广泛的应用。超细钨粉、碳化钨粉以及超细钨复 合粉末是制备高质量钨基电触头材料、电子封装材料、集成电路难熔栅 和阻挡层的溅射靶材、电子发射材料等的主要原料。超细钨粉、碳化钨 粉等的质量直接影响着这些钨基电子材料产品的最终性能,因此如何以 较低成本高效地生产出优质超细钨粉、碳化钨粉对半导体制造产业有着 重要的意义。
本文主要介绍了以氢还原氧化钨工艺制备超细钨粉、用超细钨粉制 备碳化钨粉的方法以及超细粉末的气流粉碎分级。
本文根据氧化钨氢还原理论分析了影响钨粉粒度和均匀性的因素, 并通过分析不同氧化钨原料的微观结构以及对比实验确定了制备超细钨 粉的原料。研究结果表明,制备超细钨粉应采用顺氢推舟、低还原温度、 高氢气流量和低氢气湿度、薄料层的工艺条件。紫钨由于其特殊的孔结 构,使其具有良好的透气性能,能够迅速地从还原气氛中排出水汽,从 而生产出细而均匀的钨粉,并且钨粉粒度受装舟量和氢气流量影响小, 从而可体现出它在产能上的优势。同时,紫钨在干燥的氢气中还原可不 经过产生 WO2 的中间阶段,从而得到细而均匀的钨粉。还原过程中应控 制好工艺条件,避免产生 WO2 聚集体。通过多次实验反复验证,以紫钨 为原料,确定了制备超细钨粉的最佳工艺制度,并按此工艺制度制备出
关键词:电子材料,超细钨粉,超细碳化钨粉,气流粉碎分级
第 II 页
上海交通大学硕士学位论文
ABSTRACT
RESEARCH ON PREPARATION OF ULTRAFINE TUNGSTEN POWDER AND TUNGSTEN CARBIDE POWDER
ABSTRACT
Refractory metal tungalloy, which has a series of excellent physical properties, has been widely used in several industries including semiconductor manufacturing industry. Ultrafine tungsten powder and tungsten carbide powder are the main raw materials of high-quality tungsten-base electrical contact alloys, electronic packaging materials, sputtering target materials of refractory gate and barrier layer in integrated circuit, electronic emission materials, etc. The quality of ultrafine tungsten powder and tungsten carbide powder has direct influence on the performance of these tungsten-base electronic materials, thus the manufacturing of high-quality ultrafine tungsten powder and tungsten carbide powder is crucial to semiconductor manufacturing industry.
The preparation of ultrafine tungsten carbide powder is actually the carbonization of ultrafine tungsten powder. In this paper, the influence factors of particle size of tungsten carbide powder is investigated, the results show that the most important factor is the particle size and particle size distribution of tungsten powder. As the carbonization process is realized by the reaction with carbonaceous gases on the surface of tungsten particles and by solid state diffusion of carbon black, the effect of carbonization temperature, carboni-zation time and carbon content of mixtures on particle size of tungsten carbide powder are relatively less. The optimal process condition for producing ultrafine tungsten carbide powder is established by experimental verification, and ultrafine tungsten carbide powder is produced.
The influence factors of particle size and uniformity of tungsten powder are investigated based on hydrogen reduction theories, and the raw material for producing ultrafine tungsten powder is determined according to analysis of microstructures of different tungsten oxides and contrast experiment. The results show that ultrafine tungsten powder can be prepared under the conditions of forward hydrogen flow, low reduction temperature, high hydrogen flow-rate, low hydrogen moisture and thin batch layer. The special pore structure of tungsten violet oxide gives it good air permeability and enables prompt ventilation of vapors under reduction atmosphere, thus produces fine and epigranular tungsten powder, and yet charging amount and
The ultrafine powders prepared are highly agglomerated and with broad particle size distribution. Experiments show that the technology of air stream classifying has significant effect on increase of the fineness and uniformity of ultrafine powders. Superfine pulverizing grader has high production efficiency and low energy consumption, and yet is easy to operate and control. Air stream pulverizing and grading produces ultrafine powder with less agglomeration and narrow particle size distribution. Superfine pulverizing grader significantly improves production efficiency of ultrafine powders.
超细钨粉、碳化钨粉存在分散性、均匀性差等问题。本文采用气流 粉碎分级技术可以在很大程度上消除粉末的团聚现象,并且可以使粉末 进一步细化、粒度分布合理。采用气流粉碎分级设备进行处理生产效率 高、能耗小,并且操作简单,容易控制。制备的超细颗粒粉末分散性、 均匀性大大提高,粒度组成得到明显改善;降低生产过程控制难度,彻 底解决传统生产过程中的球磨、过筛难度大的问题,大大提高生产效率, 缩短了生产周期。
第I页
上海交通大学硕士学位论文
摘要
了性能优异的超细钨粉。介绍了防止超细钨粉氧化自燃以及提高超细钨 粉产能的方法。
制备超细碳化钨粉实际上是超细钨粉的碳化过程。本文分析了影响 碳化钨粉粒度的因素,研究结果表明,钨粉的粒度和粒度组成是影响碳 化钨粉粒度和粒度组成的最主要因素。由于碳化过程主要是靠钨粉颗粒 表面与含碳气体反应以及固体炭黑向钨粉内部扩散来实现的,因此,碳 化温度、碳化时间、物料碳含量等对碳化钨粉末粒度的影响相对较小。 通过实验反复验证制定了制备碳化钨粉的工艺制度,并制备出了粒度均 匀的超细碳化钨粉。
The preparation of ultrafine tungsten powder by hydrogen reduction method, the preparation of ultrafine tungsten carbide powder by carbonization of tungsten powder, and air stream pulverizing and grading of ultrafine powders are introduced.
第 III 页
上海交通大学硕士学位论文
ABSTRACT
hydrogen flow-rate have little effect on particle size of tungsten powder. Meanwhile, under dry hydrogen atmosphere, tungsten violet oxide can be reduced directly to W without generating WO2, thus enables the production of epigranular ultrafine tungsten powder. The process conditions should be optimized to avoid the generation of WO2 agglomerations. Finally the optimal process condition for producing ultrafine tungsten powder is established by experimental verification, and ultrafine tungsten powder is produced. The methods for preventing oxidation and spontaneous combustion are introduced, and also how to improve production capacity.
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