Borosilicate Glass Sintering Agent for Low-Temperature MLCC
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Solution Overview
Problem
Existing multilayer ceramic capacitors face challenges in achieving high capacitance and reliability due to low hot insulation resistance and sintering issues when using conventional sintering agents at high temperatures, which lead to sintering shrinkage mismatch and reduced capacitance when manufacturing ultra-thin dielectric layers.
Innovation Solution
The use of borosilicate glass compositions as a sintering agent, formulated with specific ratios of alkali, alkaline earth, and rare earth oxides, allows for low-temperature sintering of ceramic dielectrics, improving hot insulation resistance and reducing sintering shrinkage mismatch between dielectric layers and internal electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high temperature sintering is performed to manufacture multilayer ceramic capacitors, then the sintering process can be completed, but sintering shrinkage mismatch occurs between dielectric layers and internal electrodes, and electrode agglomeration worsens, reducing capacitance and increasing short ratio
Solution Approach 1:
The patent changes the chemical composition parameters of the glass sintering agent by incorporating specific ratios of B2O3 (20-40 mol%), SiO2 (30-50 mol%), and metal oxides (Al2O3, TiO2, ZrO2) to modify the sintering characteristics. This compositional parameter change enables the sintering process to occur at lower temperatures (1000-1200°C) while maintaining proper shrinkage matching between dielectric layers and internal electrodes, thereby preventing electrode agglomeration and improving capacitance without increasing short ratio
Solution Approach 2:
The patent uses a composite glass sintering agent system combining multiple components: B2O3 as the primary glass former, SiO2 as the network former, and metal oxides (Al2O3, TiO2, ZrO2) as modifiers. This composite material approach creates a synergistic effect where each component contributes specific properties - B2O3 provides low-temperature melting, SiO2 provides structural stability, and metal oxides control viscosity and shrinkage characteristics, enabling effective sintering at reduced temperatures while maintaining dimensional accuracy and electrical performance
2Manufacturing precision
If conventional sintering agents are used, then the sintering process can proceed, but sintering shrinkage mismatch occurs between dielectric layers and internal electrodes, reducing manufacturing precision
Solution Approach 1:
The patent modifies the chemical composition parameters of the sintering agent to achieve specific rheological properties at lower temperatures. By adjusting the B2O3 content (20-40 mol%) and incorporating metal oxides (Al2O3: 5-15 mol%, TiO2: 5-15 mol%, ZrO2: 5-15 mol%), the patent optimizes the viscosity-temperature relationship and shrinkage characteristics of the glass phase, enabling precise shrinkage matching between dielectric layers and internal electrodes during low-temperature sintering (1000-1200°C)
Solution Approach 2:
The patent utilizes thermal expansion and shrinkage characteristics of the glass sintering agent to match the dimensional changes of both dielectric layers and internal electrodes during the sintering process. The composite glass composition is designed to exhibit thermal expansion coefficients and shrinkage behavior that are compatible with both the ceramic dielectric and metal internal electrodes, preventing differential shrinkage mismatch and maintaining manufacturing precision at lower sintering temperatures
3Quantity of substance
If dielectric layers are reduced in thickness to increase capacitance, then ultra-high capacitance can be achieved, but hot insulation resistance rapidly decreases when DC voltage is applied at usable temperatures
Solution Approach 1:
The patent employs a composite glass sintering agent system containing B2O3, SiO2, and metal oxides (Al2O3, TiO2, ZrO2) that creates a refined microstructure with fine-grained glass phase distributed throughout the dielectric. This composite material structure provides both high permittivity (enabling ultra-high capacitance with thin layers) and enhanced hot insulation resistance by forming a dense, defect-free microstructure that prevents leakage current paths even when DC voltage is applied at elevated temperatures
Solution Approach 2:
The patent changes the chemical composition parameters of the glass sintering agent to optimize the microstructural development during sintering. By controlling the ratios of B2O3 (20-40 mol%), SiO2 (30-50 mol%), and metal oxides, the patent achieves a glass phase composition that forms a fine-grained, homogeneous microstructure in ultra-thin dielectric layers. This microstructural parameter optimization simultaneously enhances permittivity for high capacitance and creates barrier properties that maintain hot insulation resistance under DC voltage stress
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The borosilicate glass compositions enable the production of multilayer ceramic capacitors with enhanced hot insulation resistance and high capacitance by sintering at temperatures of 1100° C. or less, minimizing electrode agglomeration and ensuring high reliability and X5R characteristics.
Implementation Method 1
allows for low-temperature sintering of ceramic dielectrics
Implementation Method 2
improving hot insulation resistance
Data Source
AI summary
The present invention relates to borosilicate glass compositions for a sintering agent, dielectric compositions containing the borosilicate glass compositions and a multilayer ceramic capacitor using the dielectric compositions. Borosilicate glass compositions for a sintering agent according to an aspect of the invention include an alkali oxide, an alkaline earth oxide and a rare earth oxide, can sinter ceramic dielectrics at low temperatures and improve the hot insulation resistance of a multilayer ceramic capacitor. Correspondingly, dielectric compositions including these borosilicate glass compositions and a multilayer ceramic capacitor using the dielectric compositions can be sintered at a low temperature of 1100° C. or less and have high hot insulation resistance, thereby ensuring high levels of reliability.