Modeling Stress Responses of Multilayer Capacitors Using Varying Termination Geometries

摘要

Environmental regulations and increasingly challenging design objectives have prompted the search for alternative materials in microelectronics. Employing these materials alters the reliability profile and performance characteristics of the electronic components into which they are integrated. This article explores how mechanical stresses impact the reliability of ceramic dielectric bodies of multilayer ceramic capacitors (MLCCs) when the material, shape, and thickness of the MLCC terminations were varied. The termination material, termination geometry, and thickness of the ceramic were varied. Results were obtained using finite element analysis, and a reliability model was developed and validated. A preliminary investigation indicated a relationship between the selection of materials used for capacitor termination and the emergence of cracks. Stresses that occurred when boards were subjected to conditions including cyclic bending, vibrations, temperature cycling, and high-g loading correlated to the appearance of cracks on the bottom of the capacitor in proximity to the termination.