Direct observation of cross sectional local conductive paths in a degraded multilayered ceramic capacitor

K Izawa,K Yasukawa,S Inayama,T Sada,M Utsunomiya,N Fujikawa,K Matsubara

doi:10.1063/5.0003962

K Izawa, K Yasukawa + Show 5 more

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https://doi.org/10.1063/5.0003962

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Journal: Applied Physics Letters	Publication Date: May 11, 2020
Citations: 10	License type: cc-by

Affiliation: Kyocera (Japan)

Abstract

Using scanning spreading resistance microscopy, we obtained images of local conduction paths on the cross section of a multilayer ceramic capacitor (MLCC) just before electrical breakdown. The images were observed after the local low-resistance part in the MLCC was identified as being degraded according to the highly accelerated lifetime test. Each grain in the conductive path images was clearly visible, and the insulation resistance (IR) around the cathode was lower than that near the anode. It was concluded that this is a phenomenon that accompanies the migration of oxygen vacancies. We directly observed the degraded resistance distribution of ceramic grains, which showed the bulk-limited conduction mechanism formed by IR degradation.

Highlights

Conductive atomic force microscopy and scanning spreading resistance microscopy (SSRM) have been considered promising candidates for methods of measuring the resistance distribution of grains and grain boundaries on the sub-micrometer order.8–10 To achieve this objective using these methods, it is necessary to prepare samples with degraded insulation resistance (IR) in a local region
To understand the following data, the lamination direction of the dielectric material and the internal electrode was set to the z-axis, and the long and short sides of the multilayer ceramic capacitor (MLCC) were set to the x and y axes, respectively
The value of the leakage current increased as IR degradation increased, and the applied voltage was forcibly stopped at 0.553 mA, immediately before the value of the leakage current

Summary

Introduction

Conductive atomic force microscopy and scanning spreading resistance microscopy (SSRM) have been considered promising candidates for methods of measuring the resistance distribution of grains and grain boundaries on the sub-micrometer order.8–10 To achieve this objective using these methods, it is necessary to prepare samples with degraded IR in a local region. ABSTRACT Using scanning spreading resistance microscopy, we obtained images of local conduction paths on the cross section of a multilayer ceramic capacitor (MLCC) just before electrical breakdown.

Results

Conclusion