Imaging the effect of dielectric breakdown in a multilayered polymer film
Imaging the effect of dielectric breakdown in a multilayered polymer film
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多层聚合物薄膜中介电击穿效应的成像
DOI：
10.1002/app.34269
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发表时间：
2012
影响因子：
3
通讯作者：
E. Baer
中科院分区：
文献类型：
--
作者：
M. Wolak;A. Wan;J. Shirk;M. Mackey;A. Hiltner;E. Baer
聚偏氟乙烯-六氟丙烷共聚物(P(VDF-HFP))薄膜的介电强度和储能能力通过聚偏氟乙烯-六氟丙烷共聚物(P(VDF-HFP))薄膜与聚碳酸酯(PC)薄层的交织来提高。为了深入了解这种材料的击穿过程，用聚焦离子束(FIB)球磨结合扫描电子显微镜(SEM)研究了击穿对薄膜的影响。FIB可以顺序地铣削横截面，每个横截面都由扫描电子显微镜成像。这项技术可以在整个胶片上提供准3D图像，并提供电击穿造成的损害的详细视图。在这里，使用针面电极配置开始的击穿被成像。在均匀薄膜中，损伤仅限于针孔位置的小体积。在32层50/50pC/P(VDFHFP)多层膜中，可观察到沿层界面向膜内横向延伸达�15lm的损伤。除了德拉米国家外，层的屈曲和变形也很明显。损伤随着样品取向的不同而不同，但图像表明界面在击穿中起着重要作用。他们认为，改善界面性质是进一步提高多层聚合物介电材料介电强度的一种策略。弗吉尼亚州2011年威利期刊公司†。《应用理工学》123：2548-2557,2012
The dielectric strength and energy storage capability of poly(vinylidene fluoride-hexafluoropropy- lene) copolymer (P(VDF-HFP)) films are enhanced by interleaving layers of PVDF copolymer with thin layers of polycarbonate (PC). To gain insight into the break- down processes in such materials, focused ion beam (FIB) milling in conjunction with scanning electron mi- croscopy (SEM) was used to study the effect of a break- down on the film. FIB can sequentially mill cross sections that are each imaged by SEM. The technique can provide quasi-3D images across the film and give a detailed view of the damage caused by an electrical breakdown. Here, breakdowns initiated using a needle-plane electrode con- figuration were imaged. In homogeneous films, the dam- age was confined to the small volume at the pinhole site. In 32-layer 50/50 PC/P(VDF-HFP) multilayer films, dam- age extending laterally up to � 15 lm into the film along the layer interfaces was seen. In addition to the delami- nation, layer buckling and distortion were apparent. The damage varied with the sample orientation, but the images indicate that the interfaces play an important role in the breakdown. They suggest that modifying the inter- face properties can be a strategy to further improve the dielectric strength of multilayer polymer dielectric materi- als. V C 2011 Wiley Periodicals, Inc † . J Appl Polym Sci 123: 2548- 2557, 2012