Synchrotron X-ray nano computed tomography was used to investigate the microstructural evolution during co-sintering of multi-layer ceramic capacitors (MLCC) consisting of Ni electrodes and BaTiO₃ dielectric layers stacked alternately. As the electrode thickness reduced to submicron at the scale of a few particle diameters, the process produced the defect of inner electrode leading to capacitance loss. The discontinuous electrode region contained round holes and irregularly-shaped channels. The formation of discontinuity was associated with the increase of characteristic length of heterogeneous electrode structure, i.e., the coarsening occurred. The evolution of electrode morphology by surface/interface diffusion caused the breakup of ligament between two holes driven by instability induced by surface tension and stress. The ligament pinch-off inevitably generated sharp points which might enhance the local electric field bringing about the dielectric breakdown. A model was presented to explain the formation of defect from the heterogeneous particles packing in the electrode layer.

用同步加速器X射线纳米计算机断层扫描技术研究由Ni电极和BaTiO ₃组成的多层陶瓷电容器（MLCC）共烧结过程中的微观结构演变。介电层交替堆叠。随着电极厚度在几个粒径的范围内减小到亚微米，该过程产生了内部电极的缺陷，导致了电容损耗。不连续的电极区域包含圆孔和不规则形状的通道。不连续的形成与异质电极结构的特征长度的增加相关，即发生粗化。由表面/界面扩散引起的电极形态演变导致两个孔之间的韧带破裂，这是由表面张力和应力引起的不稳定性驱动的。韧带夹断不可避免地会产生尖点，这些尖点可能会增强局部电场，从而导致电介质击穿。