【作者】 叶祖勋；

【导师】 吕文中；

【作者基本信息】 华中科技大学 ， 微电子学与固体电子学， 2006， 硕士

【摘要】 目前,叠层片式压敏电阻器(MLCV)的造价过高,其主要原因在于难以实现压敏陶瓷膜片与内电极的低温共烧(<1000℃),而必须采用烧结温度高但价格昂贵的钯或银钯做内电极。针对这个问题,本文重点研究ZnO压敏电阻的低温烧结以及流延法制膜。具体内容如下:研究各种有机添加剂(如分散剂、粘结剂、溶剂和增塑剂)在流延浆料中的作用、机理及选择原则。并根据本文需要选定实验的分散剂为蓖麻油,粘结剂为聚乙烯醇缩丁醛(PVB),溶剂为正丁醇和环己酮组成的二元混合有机溶剂,增塑剂为邻苯二甲酸二丁脂(DBP)。研究了ZnO压敏电阻的低温烧结机理和途径。通过总结各种ZnO压敏电阻陶瓷的低温烧结方案,设计出一个ZnO-Bi系压敏电阻的低温烧结材料配方,并采用干压成型法实验验证其最高烧结温度可低至950℃。实验研究制备ZnO压敏电阻的流延膜片。探讨不同配比的粘结剂、增塑剂、分散剂以及ZnO压敏电阻流延浆料中不同的固体含量对流延浆料和流延膜片性能的影响,并最终确定一个各种有机添加剂的最优的配比方案。研究ZnO压敏电阻流延膜片的排胶和烧结。实验验证本文制备的流延膜片最高烧结温度可低至950℃,该流延膜片可用于制备叠层片式压敏电阻,实现流延膜片与内电极的低温共烧。更多还原

【Abstract】 Nowadays ZnO varistor’s ceramic tape can’t be sintered with inner electrode below 1000℃, so Pd and Pd/Ag must be chosen as MLCV’s inner electrode, that have higher sintering temperature but more expensive than pure Ag. This is why the cost of MLCV is too high. To solve the problem above, low temperature sintering of ZnO varistor ceramics and tape-casting of ZnO varistor ceramic tape were studied in this paper. The conclusions are as following:The organic additives’mechanism, selective rules and their roles in preparing tape-casting ceramic slurry were discussed. The organic additives included dispersant, binder, plasticizer and solvent. Based on the characteristic of ZnO varistor’s green powder, castor oil was chosen as dispersant, PVB was chosen as binder, DBP was chosen as plasticizer, and n-butanol with cyclohexanone were chosen as dual-combining solvent. The mechanism and the methods of low temperature sintering ZnO varistor ceramics were investigated. After summarizing several designs for low temperature sintering ZnO varistor ceramics, an optimal recipe for low temperature sintering ZnO-Bi varistor ceramics was presented. To prove the property of the recipe, some ZnO varistor specimens were made by traditional dried mould process using the optimal recipe mentioned above. And the experimental results showed that, the sintering temperature of the specimens could be as low as 950℃.The experiment of preparing ZnO varistor’s green tape using tape-casting technique had been done. And the influence of organic additives’different adding amount on the property of ceramic slurry and the ZnO varistor’s green tape were studied systematically. Finally the best adding amount of the organic additives including dispersant, binder, plasticizer and solvent were determined.The organic burnout process and the sintering process of green tape prepared by tape-casting were discussed. The experimental results showed that, the ZnO varistor’s green tape could successfully be sintered at 950℃. This tape could be used for manufacturing MLCV.更多还原