Ceramic Composition for High Flexural Strength and Q Value
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ceramic compositions with low flexural strength and insufficient Q value in the microwave band, requiring specialized burning containers and prone to composition variations due to the presence of B components, which are volatile during firing.
Innovation Solution
A ceramic composition comprising 47.0 to 67.0 wt.% SiO2, 21.0 to 41.0 wt.% BaO, 10.0 to 18.0 wt.% Al2O3, with CeO2 and MnO as additives, and optionally ZrO2, TiO2, ZnO, Nb2O5, CoO, and V2O5, sintered without Cr and B components, allowing for simpler firing and improved mechanical and dielectric properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If B component is added to ceramic composition, then Q value is improved, but composition variation occurs due to scattering during burning
Solution Approach 1:
The patent removes the B component from the ceramic composition entirely, extracting the problematic element that causes scattering during burning. This eliminates composition variation while maintaining acceptable Q values through alternative compositional design focusing on SiO2, BaO, and Al2O3 in specific proportions.
Solution Approach 2:
The patent changes the compositional parameters by specifying precise ranges for SiO2 (47.0-67.0 wt%), BaO (21.0-41.0 wt%), and Al2O3 (10.0-18.0 wt%), along with controlled amounts of CeO2 (1.0-5.0 parts by weight) and MnO (2.5-5.5 parts by weight). This parameter optimization achieves both stability and performance without B component.
2Device complexity
If Mn component is used instead of B component, then burning complexity is reduced, but flexural strength and Q value become insufficient
Solution Approach 1:
The patent creates a composite ceramic system combining SiO2-BaO-Al2O3 base composition with CeO2 and MnO additives. This composite approach achieves flexural strength of 280 MPa or more and Q×f value of 1000 or more, surpassing conventional Mn-only compositions while maintaining simple burning processes without container-like sheath requirements.
3Reliability
If Cr component is added to ceramic composition, then certain properties are improved, but environmental and chemical resistance deteriorate
Solution Approach 1:
The patent explicitly excludes Cr component from the ceramic composition, removing the element that compromises environmental and chemical resistance. The desired properties are achieved through optimized SiO2, BaO, and Al2O3 ratios combined with CeO2 and MnO additives, eliminating the need for Cr while maintaining or improving overall performance and resistance properties.
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 ceramic composition achieves higher flexural strength (up to 280 MPa) and Q×f values (up to 1200 at 3 GHz), reduces firing complexity, and enhances environmental and chemical resistance.
Implementation Method 1
a ceramic composition, method for producing the same, ceramic substrate and method for producing ceramic green layer
Data Source
AI summary
To provide a ceramic composition not only having little compositional variation after burning, but a high flexural strength of the sintered body, and a high Q value in a microwave band, a ceramic composition used for forming a ceramic layer of a multi-layer ceramic substrate contains 47.0 to 67.0 wt. % of SiO2, 21.0 to 41.0 wt. % of BaO, and 10.0 to 18.0 wt. % of Al2O3, and contains as a first additive, 1.0 to 5.0 parts by weight of CeO2, relative to a total of 100 parts of SiO2, BaO and Al2O3, and as a second additive, 2.5 to 5.5 parts by weight of MnO, relative to a total of 100 parts by weight of SiO2, BaO, Al2O3 and CeO2, and is substantially free of Cr. As a third additive, at least one of Zr, Ti, Zn, Nb, Mg and Fe, and as a fourth additive, a Co component and/or a V component, may be contained.