Stober法制备二氧化硅微球工艺研究

发布时间：2018-02-19 19:11

本文关键词： Stober法二氧化硅微球电子封装一步法连续滴加法　出处：《西安电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文致力于通过Stober法合成用于电子封装中的二氧化硅微球。我们首先探讨了二氧化硅的广阔应用前景,以寻求它的潜在应用价值。文中综述了Stober法的来源及相关的研究工作进展,以及Stober法中二氧化硅微球的合成机理及基于亚颗粒团聚和单体添加的生长模型。在一步添加法中,研究了反应时间、温度、正硅酸乙酯浓度、水浓度及氨浓度对微球形貌、粒径和分布的影响。其中随着反应时间的延长,颗粒粒径随之增大,但反应较为迅速,在一到两小时,反应已基本完成。反应温度越高,颗粒粒径越小,同时单分散性也变差。随着水浓度的提高,颗粒的均匀性变好,同时颗粒的粒径先增加后减小,在12mol/L附近时达到最大值。正硅酸乙酯的浓度越高,颗粒粒径越大。当氨浓度从0.5mol/L增加到3mol/L时,颗粒的粒径随之增大,但粒径分布倾向于变宽。为了扩大微球的粒径,减少初期成核的微晶核的数目,采用连续滴加法,在水解液中滴加硅源溶液,以获得更少的晶核。试样的扫描电子显微镜图片表明:搅拌速率越低,最终获得的微球越均一,在高的搅拌速率下,微球呈现多尺度的分布。使用激光粒度散射仪测量了颗粒的粒度分布,发现颗粒呈单分散分布。为了进一步减少初期的成核数目,通过在水解液中添加电解质氯化钾,降低亚颗粒的表面电位,加速颗粒的团聚作用。在滴加速率为0.834ml/min时,当氯化钾浓度从0mM到6mM时,颗粒的粒径增加,分布更均匀。随着滴加速率的降低,颗粒自由生长过程的延长,颗粒的粒径增加,均匀性增强。共溶剂中水的浓度越低,颗粒的均匀性越好。
[Abstract]:This paper is devoted to the synthesis of silica microspheres for electronic packaging by Stober method. In order to seek its potential application value, this paper reviews the source and related research progress of Stober method, the synthesis mechanism of silica microspheres in Stober method and the growth model based on sub-particle agglomeration and monomer addition. The effects of reaction time, temperature, ethyl orthosilicate concentration, water concentration and ammonia concentration on the morphology, particle size and distribution of microspheres were studied. The reaction was basically completed. The higher the reaction temperature, the smaller the particle size and the worse the monodispersity. With the increase of water concentration, the uniformity of the particle became better, and the particle size first increased and then decreased. The higher the concentration of ethyl orthosilicate, the larger the particle size. When ammonia concentration increased from 0.5 mol / L to 3 mol / L, the particle size increased, but the particle size distribution tended to widen. The number of micrystalline nuclei in the initial nucleation was reduced, and the silicon source solution was added in the hydrolysate by a continuous drop addition method to obtain fewer crystal nuclei. The SEM images of the samples showed that the lower the stirring rate, the more uniform the final microspheres were obtained. At high stirring rate, the microspheres show a multi-scale distribution. The particle size distribution is measured by laser particle size scattering instrument, and the particle size distribution is found to be monodisperse. In order to further reduce the nucleation number in the initial stage, the particle size distribution is found to be monodisperse. By adding electrolyte potassium chloride to the hydrolysate, the surface potential of the sub-particles was decreased and the agglomeration of the particles was accelerated. When the dropping rate was 0.834 ml / min, the particle size increased when the concentration of potassium chloride was from 0 mm to 6 mm. With the decrease of dropping rate and the prolongation of the free growth process, the particle size increases and the uniformity increases. The lower the concentration of water in the co-solvent, the better the uniformity of the particles.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.2

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