1. Deformation and crack growth in multilayered ceramic capacitor during thermal reflow process: numerical and experimental investigation.
- Author
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Apalowo, Rilwan Kayode, Abas, Mohamad Aizat, Bachok, Zuraihana, Sharif, Mohamad Fikri Mohd, Che Ani, Fakhrozi, Ramli, Mohamad Riduwan, and Mukhtar, Muhamed Abdul Fatah bin Muhamed
- Subjects
FRACTURE mechanics ,CERAMIC capacitors ,SCANNING electron microscopes ,FINITE element method ,COPPER ,LEAD time (Supply chain management) - Abstract
Purpose: This study aims to investigate the possible defects and their root causes in a soft-termination multilayered ceramic capacitor (MLCC) when subjected to a thermal reflow process. Design/methodology/approach: Specimens of the capacitor assembly were subjected to JEDEC level 1 preconditioning (85 °C/85%RH/168 h) with 5× reflow at 270°C peak temperature. Then, they were inspected using a 2 µm scanning electron microscope to investigate the evidence of defects. The reliability test was also numerically simulated and analyzed using the extended finite element method implemented in ABAQUS. Findings: Excellent agreements were observed between the SEM inspections and the simulation results. The findings showed evidence of discontinuities along the Cu and the Cu-epoxy layers and interfacial delamination crack at the Cu/Cu-epoxy interface. The possible root causes are thermal mismatch between the Cu and Cu-epoxy layers, moisture contamination and weak Cu/Cu-epoxy interface. The maximum crack length observed in the experimentally reflowed capacitor was measured as 75 µm, a 2.59% difference compared to the numerical prediction of 77.2 µm. Practical implications: This work's contribution is expected to reduce the additional manufacturing cost and lead time in investigating reliability issues in MLCCs. Originality/value: Despite the significant number of works on the reliability assessment of surface mount capacitors, work on crack growth in soft-termination MLCC is limited. Also, the combined experimental and numerical investigation of reflow-induced reliability issues in soft-termination MLCC is limited. These cited gaps are the novelties of this study. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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