Multilayer Ceramic Capacitor Composition for Thermal Shock Resistance
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Solution Overview
Problem
Existing multilayer ceramic electronic devices lack sufficient thermal shock resistance due to the formation of segregates and variations in the coefficient of linear thermal expansion between dielectric and electrode layers.
Innovation Solution
A multilayer ceramic electronic device with dielectric layers containing specific compositions and ratios of components such as BaTiO3, Mn oxide, Mg oxide, R oxide, Zr oxide, and Si, along with a Zr/Mn and Zr/Si atomic ratio, which promotes the formation of Si segregates at interfaces to mitigate thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dielectric compositions are used, then manufacturing is simpler, but thermal shock resistance is insufficient
Solution Approach 1:
The patent applies parameter changes by precisely controlling the compositional parameters of the dielectric layer. Specifically, it limits Mn oxide to above 0 mol and less than 0.050 mol, Mg oxide to 1.00 mol or more and 2.50 mol or less, R oxide to 0.50 mol or more and 1.50 mol or less, and Zr oxide to 0.05 mol or more and 0.45 mol or less with respect to 100 mol of BaTiO3. These parameter constraints optimize thermal shock resistance while maintaining manageable manufacturing complexity.
Solution Approach 2:
The patent employs composite materials by creating a multi-component dielectric system combining BaTiO3 with controlled amounts of Mn oxide, Mg oxide, R oxide (where R includes at least one of Y, Dy, Ho, Yb, Lu, Gd, or Tb), and Zr oxide. This composite composition achieves superior thermal shock resistance through synergistic effects of the different oxide components, particularly the formation of Si segregates at the electrode-dielectric interface.
2Reliability
If segregates are formed to reduce thermal expansion variance, then thermal shock resistance improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent defines specific parameter ranges for each oxide component to ensure proper segregate formation. The Zr oxide content (0.05-0.45 mol) and Si content (0.05-0.45 mol) are particularly critical for forming Si segregates at the electrode interface. These parameter specifications balance the need for segregate formation with manufacturability, avoiding overly stringent precision requirements while achieving reliable thermal shock resistance.
Solution Approach 2:
The patent uses Si as an intermediary element that forms segregates at the electrode-dielectric interface. These Si segregates act as a buffer zone that reduces the variance in the coefficient of linear thermal expansion between the electrode layer and dielectric layer, thereby improving thermal shock resistance without requiring extreme manufacturing precision.
3Reliability
If Zr oxide and Si are added to control thermal expansion, then thermal shock resistance improves, but dielectric layer composition complexity increases
Solution Approach 1:
The patent integrates Zr oxide and Si into a composite dielectric system with BaTiO3 as the base material. The specific composition ranges (Zr oxide: 0.05-0.45 mol, Si: 0.05-0.45 mol, along with controlled Mn oxide, Mg oxide, and R oxide) create a multi-functional composite that simultaneously achieves thermal shock resistance, proper sintering characteristics, and acceptable manufacturing complexity.
Solution Approach 2:
The patent applies local quality by allowing Si to segregate specifically at the electrode-dielectric interface rather than being uniformly distributed. This localized segregation of Si, facilitated by the presence of Zr oxide in the dielectric bulk, provides thermal expansion buffering exactly where needed (at the interface) without requiring Si throughout the entire dielectric layer, thus managing composition complexity more effectively.
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
Enhances thermal shock resistance by reducing the variance in the coefficient of linear thermal expansion and improving the coverage ratio of electrode layers, resulting in improved reliability and capacitance.
Implementation Method 1
a variance in a coefficient of linear thermal expansion between the dielectric layer and the electrode layer, the multilayer ceramic electronic device has low thermal shock resistance
Data Source
AI summary
A multilayer ceramic electronic device includes an element body including a dielectric layer and an electrode layer laminated. The dielectric layer contains a main component represented by ABO3. The dielectric layer contains above 0 mol and less than 0.050 mol Mn oxide in terms of MnO; 1.00 mol or more and 2.50 mol or less Mg oxide in terms of MgO; 0.50 mol or more and 1.50 mol or less R oxide in terms of R2O3, where R includes at least one of Y, Dy, Ho, Yb, Lu, Gd, and Tb; and 0.05 mol or more and 0.45 mol or less Zr oxide in terms of ZrO2, with respect to 100 mol of the main component and further contains Si. The dielectric layer has a Zr/Mn ratio of 5.0 or more and 12.5 or less and a Zr/Si ratio of 0.40 or more and 0.80 or less in atomic ratio.