MLCC Electrode Coverage Layout for Electrostrictive Stress Relief

The patent applies local quality by creating three distinct coverage regions (first, second, and third regions) within the internal electrode layers, where each region has a different coverage ratio. The first region has a higher coverage ratio than the second region, and the third region has a lower coverage ratio than the second region. This localized variation in coverage ratios allows different portions of the electrode layers to handle stress differently, with the low-coverage third region specifically designed to reduce stress concentration in the dielectric layers while maintaining overall high capacitance density through the high-coverage first region.

The patent segments the internal electrode layers into three distinct coverage regions (first, second, and third regions) with different coverage ratios. The first region provides high connectivity to external electrodes with a higher coverage ratio, the second region serves as a transition zone with intermediate coverage, and the third region reduces stress concentration with a lower coverage ratio. This segmentation allows the electrode structure to simultaneously achieve good connectivity through the high-coverage first region and reduced stress through the low-coverage third region, resolving the contradiction between connectivity and stress concentration.

The patent converts the harmful electrostrictive effect into a beneficial design parameter by strategically varying the coverage ratios of internal electrode layers across different regions. The low-coverage third region specifically addresses the stress concentration problem generated by the electrostrictive effect of ferroelectric materials, while the high-coverage first region maintains the high capacitance density benefit. This approach allows the use of high-permittivity ferroelectric materials while mitigating their harmful electrostrictive effects through clever structural design.