多层陶瓷电容器可靠性研究

STUDY ON RELIABILITY OF MULTI-LAYER CERAMIC CAPACITOR

陈小剑

11930434

硕士

材料工程

杨改英

2021-05-18

2021-06-07

南方科技大学

深圳

贱金属多层陶瓷电容器（Base Metal Electrode Multi-layer Ceramic Capacitor， BME-MLCC）由于其具有高容量体积比，价格低廉等优点已经成为电容市场中占比较高的基础电容元件。随着各类电子设备和器件的精密化和使用情景多样化，BME-MLCC呈现出小型化、高容量化和高可靠性化的发展趋势。其中，可靠性直接反映了器件在电路中长时间工作的稳定性，是每个电子产品生产过程中不可忽视的性能指标。本文主要研究了商业镍电极钛酸钡（Ni-BaTiO3） MLCC的可靠性，探究了其性能劣化过程中的宏观性能变化以及微观结构化学变化。本文通过实验室自行搭建的高加速寿命实验平台对MLCC进行可靠性测试，获得了不同劣化阶段的样品，即正常样品、劣化样品以及失效样品。通过绝缘电阻测试分析了不同劣化阶段MLCC样品绝缘电阻的温度依赖性以及测试电场方向对绝缘电阻的影响，验证了MLCC性能劣化的氧空位迁移理论。通过扫描电镜、透射电镜、X射线能谱、X射线光电子能谱等手段分析了不同劣化阶段的MLCC样品的微观结构和化学变化。结果表明该款MLCC中存在Si元素和Dy元素掺杂，并且Dy元素参与形成了“芯-壳”结构。另外，随MLCC劣化，其内部可能产生不同形式的异常结构，如分层或存在失效区，交流阻抗谱证明了劣化前期晶界激活能下降，晶界电阻的劣化是MLCC前期性能劣化主要原因。对经交流阻抗测试后的样品进行性能测试，发现失效样品存在性能回复现象，其充电性能与绝缘性能均回复到正常样品水准，该现象可能与氧空位在交流电场下的重新分布相关，具体机理有待进一步研究。

Base metal electrode multi-layer ceramic capacitor (BME-MLCC), being a basic capacitive element, has taken up a relatively high market share in the capacitor market because of its high capacity-to-volume ratio and low price. With the sophistication and diversification of usage of scenarios of various electronic equipment and devices, BME-MLCC shows a development trend of miniaturization, high capacity and high reliability. Among them, reliability directly reflects the stability of electronic devices when they work in the circuit for a long time, is a vital property indication of every electronic product during its manufacture process. Thus, this work mainly studies the reliability of commercial nickel electrode barium titanate MLCCs, explores the changes of their macroscopic performance, microstructure and chemical reaction during their performance degradation. In this work, the reliability test of MLCC is carried out on the laboratory's self-built high-accelerated life test platform, and samples of different deterioration stages are obtained, namely normal samples, deteriorated samples and failed samples. With the insulation resistance test, the temperature dependence of the insulation resistance of the MLCC samples at different degradation stages and the influence of the test electric field direction on the insulation resistance were analyzed, and the oxygen vacancy migration theory of the degradation of MLCC performance was verified. The microstructure and chemical changes of MLCC samples at different stages of deterioration were analyzed by scanning electron microscope, transmission electron microscope, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy. The results show that there are Si and Dy elements doped in this commercial MLCC, and Dy element participates in the formation of "core-shell" structure. Besides, as the MLCC deteriorates, different forms of abnormal structures may occur inside the MLCC, such as delamination or existing a failure zone. Impedance spectroscopy proves that the grain boundary activation energy in the early stage of deterioration is reduced, showing that the deterioration of the grain boundary resistance is the main reason for the early deterioration of MLCC. The performance test of the sample after the AC impedance test found that the performance of the failed sample has a recovery phenomenon, and the charging performance and insulation performance have returned to the normal sample level. This phenomenon may be related to the redistribution of oxygen vacancies under an alternating current (AC) electric field. The specific mechanism needs further study.

多层陶瓷电容器 可靠性 高加速寿命实验 绝缘电阻 微观结构和化学变化

multilayer ceramic capacitors reliability highly accelerated life test insulation resistance microstructure and chemical changes

中文

独立培养

南方科技大学

陈小剑. 多层陶瓷电容器可靠性研究[D]. 深圳. 南方科技大学,2021.