A strategy to detect the effect of electrode defects on the electrical reliability in multilayer ceramic capacitors

Direct Observation of Local Dielectric Conductive Paths and Their Dynamics in the Degraded Multilayer Ceramic Capacitors

“…[ 8–14 ] In MLCCs, previous macroscopic measurements have clearly demonstrated the role of oxygen vacancies in the degradation failure of MLCCs; recent work turns to scanning probe microscopy for understanding local insulation resistance degradation of MLCCs, especially Kelvin probe force microscopy, which can give high‐spatial‐resolution surface potential measurements, providing information about the electric field concentrated distribution of degraded dielectric layers. [ 15–24 ] However, for the dielectric breakdown conductive path and its dynamics under electric fields, it is still in the frame of theoretical modeling process, and few studies have been done in the direct imaging of the local conductive path, [ 25 ] and their dynamics in response to the loading fields, which gives a great limitation to understanding local degradation mechanism for MLCCs’ failure. [ 26–28 ]…”

“…[8][9][10][11][12][13][14] In MLCCs, previous macroscopic measurements have clearly demonstrated the role of oxygen vacancies in the degradation failure of MLCCs; recent work turns to scanning probe microscopy for understanding local insulation resistance degradation of MLCCs, especially Kelvin probe force microscopy, which can give high-spatial-resolution surface potential measurements, providing information about the electric field concentrated distribution of degraded dielectric layers. [15][16][17][18][19][20][21][22][23][24] However, for the dielectric breakdown conductive path and its dynamics under electric fields, it is still in the frame of theoretical modeling process, and few studies have been done in the direct imaging of the local conductive path, [25] and their dynamics in response to the loading fields, which gives a great limitation to understanding local degradation mechanism for MLCCs' failure. [26][27][28] Here, considering the difference of thermal conductivity between local dielectric layer (lower thermal conductive, insulatelike phase) and local conductive path (higher thermal conductive, metal-like phase), we proposed scanning thermal microscopy, a powerful tool for local thermal physics characterization, [29][30][31][32][33][34][35][36] to perform direct imaging of the degraded MLCCs by the highly accelerated life test (HALT) method, and successfully obtained local dielectric conductive paths and their electrical tree dynamic behaviors under the dc bias on and off state.…”

Synchrotron X‐ray multiscale tomography: Visualization of heterogeneous microstructures and defects in ceramics

“…104 Local electric field concentration is found near electrode roughness, discontinuity, and pores. 105 The multilayer structures are unstable under internal stresses arising from differential shrinkage during co-sintering. 106 The Ni electrode layer is under tensile stress at temperatures from 500 to 1000 • C because the shrinkage rate of the electrode is higher than the dielectric layer.…”

“…The degradation of insulation resistance occurs locally from the cathode where the local thickness of the dielectric layer is slightly thinner 104 . Local electric field concentration is found near electrode roughness, discontinuity, and pores 105 …”

High DC-Bias Stability and Reliability in BaTiO3-Based Multilayer Ceramic Capacitors: The Role of the Core–Shell Structure and the Electrode

“…Owing to the mismatch between the densification kinetics of the Ni electrode and BaTiO 3 , the densification onset temperature of Ni (∼450 °C) is much lower than that of BaTiO 3 (∼1000 °C). , Consequently, Ni electrodes are easily interrupted by tensile stress, forming defects such as electrode discontinuities and pores. Several previous research, utilizing simulation and experiment methods, detected that the electric field is concentrated near electrode defects, leading to an increase in leakage current density and degradation of MLCC reliability. − Hence, MLCCs with high electrode continuity have become an urgent market demand. In addition, as the dielectric layer thickness and BaTiO 3 particle size gradually decrease, the Ni particle size in the electrode paste should also decrease to match the size of BaTiO 3 particles .…”