Multilayer Capacitor Dielectric Composition for Crack-Resistant Side Margins
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multilayer ceramic capacitors face challenges in ensuring the densification and crack resistance of side margins, particularly in ultra-small and high-capacity products, where voids or cracks may occur between the laminate and side margins, affecting the reliability and performance of the capacitors.
Innovation Solution
A dielectric composition comprising a BaTiO3-base main component, a first subcomponent with Nb and Gd components, a second subcomponent with an Mg component, and a third subcomponent with Ba and Ca components, where the molar ratios of these components are carefully controlled to enhance densification and suppress grain growth, thereby improving the reliability and strength of the side margin portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the dielectric layer and internal electrode are formed to be thin to achieve miniaturization, then the capacitor size is reduced, but the side margin becomes more prone to voids and cracks
Solution Approach 1:
The patent modifies the chemical composition parameters of the side margin dielectric material by incorporating specific amounts of Nb (0.1-5 mol%), Gd (0.1-5 mol%), Mg (0.1-5 mol%), Ba (0.1-5 mol%), and Ca (0.1-5 mol%) oxides. These compositional changes enhance the sintering characteristics and mechanical properties of the side margin, preventing voids and cracks while maintaining the thin-profile design of the capacitor.
Solution Approach 2:
The side margin dielectric is formulated as a composite material system based on BaTiO3 with multiple dopant oxides (Nb2O5, Gd2O3, MgO, BaO, CaO). This composite approach combines the high dielectric constant of BaTiO3 with the beneficial effects of each dopant: Nb for grain growth control, Gd for dielectric stability, Mg for crack resistance, and Ca for sintering enhancement, thereby achieving both miniaturization and improved reliability.
2Area of stationary object
If a side margin is separately attached to the electrode exposed surfaces, then the electrode area is maximized, but densification of the side margin becomes difficult
Solution Approach 1:
The patent optimizes the chemical composition parameters of the side margin dielectric material to achieve excellent sintering characteristics. By controlling the content of specific oxides (Nb2O5: 0.1-5 mol%, Gd2O3: 0.1-5 mol%, MgO: 0.1-5 mol%, BaO: 0.1-5 mol%, CaO: 0.1-5 mol%), the material achieves low eutectic temperature and high reactivity, enabling complete densification even in separately attached side margins without voids or cracks.
Data Source
AI summary
A dielectric composition and a multilayer capacitor including the same are provided. The dielectric composition includes a BaTiO3-base main component, a first subcomponent including an Nb component and a Gd component, a second subcomponent including an Mg component, and a third subcomponent including a Ba component and a Ca component. The first subcomponent is included in an amount of 4 moles or less per 100 moles of the main component. In the first subcomponent, a molar content of Nb and a molar content of Gd satisfy 0.33≤Nb/Gd, and in the third subcomponent, a molar content of Ba and a molar content of Ca satisfy 0.2≤Ca/(Ba+Ca).