多层片式陶瓷元件用镍复合粉体及其电极研究

发布时间：2018-09-08 19:57

【摘要】：多层片式元件由于其小体积、高性能、适合于表面贴装等优点被广泛应用,其中多层片式热敏电阻与多层片式压敏电阻经常同时作为电路保护元件使用,将二者复合具有现实意义。内电极是多层片式热/压敏元件的重要组成部分,若使用贱金属镍为内电极可大大降低成本。以镍作为内电极需有三个难题需解决。首先,镍的氧化;其次,镍与瓷体的收缩匹配;最后,内电极与瓷体界面之间的互渗与反应。本文对镍表面进行了改性,用化学法合成Ni/BaTiO3复合粉体及Ni/ZnO复合粉体,复合粉体两相均匀混合,为BaTiO3或ZnO包覆镍结构。一则粉体的抗氧化性提高;二则由于包覆层为瓷体材料,一方面使复合粉体与瓷体收缩匹配,另一方面不影响瓷体的性能。如此获得的复合粉体用作多层片式热/压敏元件内电极的导电相。首先,分别采用水热沉淀法与水热结晶法合成了Ni/BaTiO3与Ni/Zn O复合粉体,并对合成过程中影响复合粉体结构和相组成的反应条件如镍粉预处理、水解调节剂浓度等进行研究,制备出相纯净、抗氧化性能提高、收缩性得到改善的复合粉体。其次,用复合粉体合成了相应的电极浆料。对浆料的导电性、烧结特性等进行了研究。又将复合粉体浆料应用于瓷体,研究了浆料与瓷体的匹配共烧性能。复合粉体电极浆料能烧结成膜且导电性满足使用要求。Ni/BaTiO3电极浆料的收缩性与瓷体相匹配,且与瓷体共烧时未出现分层等缺陷。
[Abstract]:Multilayer chip components are widely used for their small volume and high performance, which are suitable for surface mount, among which multilayer thermistors and multilayer varistors are often used as circuit protection elements. It is of practical significance to compound the two. The internal electrode is an important part of the multilayer thermal / varistor. If the base metal nickel is used as the internal electrode, the cost can be greatly reduced. Using nickel as an internal electrode requires three problems to be solved. Firstly, the oxidation of nickel; secondly, the shrinkage match between nickel and porcelain; finally, the mutual permeation and reaction between internal electrode and porcelain. In this paper, the surface of nickel was modified. Ni/BaTiO3 composite powder and Ni/ZnO composite powder were synthesized by chemical method. The composite powder was uniformly mixed in two phases, and the nickel structure was coated with BaTiO3 or ZnO. In one case, the oxidation resistance of the powder is improved; second, because the coating layer is porcelain material, on the one hand, the composite powder is matched with the ceramic body, on the other hand, the properties of the ceramic body are not affected. The composite powder can be used as the conductive phase of the inner electrode of the multilayer thermal / pressure sensitive element. Firstly, Ni/BaTiO3 and Ni/Zn O composite powders were synthesized by hydrothermal precipitation method and hydrothermal crystallization method respectively. The reaction conditions such as pretreatment of nickel powder and concentration of hydrolytic modifier were studied. The composite powders with pure phase, improved oxidation resistance and better shrinkage were prepared. Secondly, the corresponding electrode paste was synthesized from the composite powder. The electric conductivity and sintering characteristics of slurry were studied. The composite powder paste was applied to the ceramic body, and the matching co-firing property between the paste and the ceramic body was studied. The composite powder electrode paste can be sintered to form a film and the electrical conductivity meets the requirements of the application. The shrinkage of the composite powder electrode paste matches the ceramic body and there are no delamination when the composite powder electrode paste is co-fired with the ceramic body.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.3

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