XJIPC OpenIR  > 材料物理与化学研究室
片式NTC热敏电阻的制备和性能研究
王海珍
Subtype硕士
Thesis Advisor康雪雅
2011-05-31
Degree Grantor中国科学院研究生院
Place of Conferral北京
Degree Discipline微电子学与固体电子学
Keyword片式ntc 流延工艺 低温烧结 电性能。
Abstract随着现代电子技术和通信技术的飞速发展,及电子装备小型化、轻型化、高速化、多功能、高可靠性的要求,现代电子元件正逐步向片式化、叠层化方向发展。采用叠层共烧制备的片式NTC热敏电阻具有体积小、室温电阻率低等优点,被广泛应用于电信、家用电器、汽车及医疗等领域的温度控制、温度检测、温度补偿、集成电路的保护,从而成为电子元件研究的热点。在制备叠层片式NTC热敏电阻的工艺上还需要克服这两方面的难点:1)探索均匀、致密的片式成膜工艺;2)研究低温共烧结技术。因此,本文尝试用流延成型工艺制备叠层单片式热敏电阻,及掺杂、添加助溶剂的方法降低NTC热敏陶瓷材料的烧结温度。 探索用流延成型工艺制备叠层单片式热敏电阻。先用流延工艺制备热敏陶瓷膜片,然后通过叠层、热压、切割、排粘、烧结等工艺制备叠层单片式NTC热敏电阻,最后把用流延工艺制备叠层单片式NTC热敏电阻与传统等静压工艺制备的单片式NTC热敏电阻相比较。采用XRD、SEM对其微观结构进行研究,并对两种工艺制备样品的电学特性和老化特性进行分析,结果表明:流延工艺制备的样品为尖晶石立方相,等静压工艺制备的样品为尖晶石四方相;这两种工艺均能制备性能优良的NTC热敏电阻。 为了实现NTC热敏陶瓷材料与Ag电极共烧结,本文尝试了掺杂、添加助熔剂(SiO2、PbO等)的方法,并研究了添加助熔剂对Mn-Co-Ni-O系半导体陶瓷烧结特性、显微结构及电学特性。结果表明:0-2.4wt%SiO2提高了Mn-Co-Ni-O系半导体陶瓷样品的室温电阻率和材料常数B,这一实验现象可以用“电子跃迁阻断模型”来解释:Si4+离子填充八面体间隙,占据Mn4+离子的位置,减少了与Mn3+ 离子相邻的Mn4+离子的浓度,阻断了电子从Mn3+® Mn4+的跃迁,增大了电子跃迁的激活能。在Mn-Co-Ni-O系半导体陶瓷样品中添加15wt%PbO可以使陶瓷材料的烧结温度降地到950℃以下,可以实现NTC热敏材料和内电极的共烧结,此时样品的还具有较好的老化稳定性,当该陶瓷材料的烧结温度为950℃时,该陶瓷样品的ρ25和B值分别为490Ω·cm和3969K,具有较低的ρ25和较高的B值。
Other AbstractWith the rapid development of modern electrical and communication technology, miniaturization, portability, high speed, multifunction and high reliability have become the main demand of the electrical device. Modern electronic component development gradually turned to multilayer and chip type. The multilayer chip type NTC thermistor have the advantage of small size and low resistivity at room temperature. So they have already experienced intensive investigations for their wide usage of temperature control, temperature detection, temperature compensation and the integrate circuit safeguard in the field of telecommunication, household electric appliances, automobile and medicine. But there are still some obstacles in the preparation of multilayer chip type NTC thermistors, such as: 1) finding a uniform and dense film-forming process; 2) inventing a co-sintering technology at low temperature. To overcome these obstacles above, we use tape casting process to prepare uniform and dense multilayer chip NTC thermistors. And then we attempt to decrease the co-sintering temperature by adding flux agents into the system. Multilayer chip type NTC thermistors are prepared by following steps: 1) obtaining the uniform films by tape casting process; 2) stacking the films together; 3) compacting by hot isostatic pressing process; 4) cutting to chip-shape; 5) pre-sintering to eliminate the decomposable components; 6) co-sintering to form uniform and dense NTC thermistors. In this paper, The performances of thermistors prepared by multilayer route are compared with the ones prepared by molding method. The structural properties were investigated by XRD and SEM. The electrical properties and aging characteristics of the samples were measured. The results show that the NTC thermistors prepared by casting process are spinel cubic phase, and the samples prepared by isostatic pressing are the tetragonal phase, the two methods can be adopted to prepare the NTC thermistor of excellent properties. In order to co-sinter the uniform films together with Ag electrode material, flux agents (such as: SiO2, PbOetc.) are added into the sintering system. The effects of flux agents on the sinter properties, microstructure and electrical properties of the Mn-Co-Ni-O system are characterized. The results show that the additive of 0-2.4wt%SiO2 can araise the relative resistanc, material constant (B) of Mn-Co-Ni-O based ceramics. These results can be explained by “The modle of electron hopping forbidden” proposed in this paper. Si4+ ions occupy the nomal interspace, which lead to the deciease of Mn4+ concentration abuted on Mn3+. The electronic transitions from Mn3+ to Mn4+ are forbidden. So, the activative energy is rised. The co-sintering temperature of the Mn-Co-Ni-O system could be decreased to 950℃ when the amount of the PbO is 15 wt.%. At this point, a low resistivity at room temperature and a high B value could be obtained, the ρ25 =490Ω·cm and B = 3969K.
Document Type学位论文
Identifierhttp://ir.xjipc.cas.cn/handle/365002/4421
Collection材料物理与化学研究室
Affiliation中国科学院新疆理化技术研究所
Recommended Citation
GB/T 7714
王海珍. 片式NTC热敏电阻的制备和性能研究[D]. 北京. 中国科学院研究生院,2011.
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