Glass-Ceramic Grain Coating for Low-Permittivity High-Q Components
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Solution Overview
Problem
Current electronic components face challenges in achieving low permittivity, improved strength, and high Q-value simultaneously, especially with the development of high-frequency properties required for 5G mobile communication and electronic vehicles, as traditional ceramic sintered bodies struggle to balance these characteristics.
Innovation Solution
A glass ceramic sintered body is developed, featuring a main phase grain of cordierite or indialite with a forsterite phase coating layer, and a composite oxide coating layer containing Mg, Si, and Zn, which helps maintain stress and prevent crack formation, thereby achieving low permittivity, high strength, and high Q-value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a glass ceramic sintered body with low permittivity material is used, then permittivity is reduced, but strength and Q-value cannot be improved simultaneously
Solution Approach 1:
The patent uses a composite glass ceramic sintered body consisting of multiple phases: a main phase (cordierite or indialite) providing low permittivity, and a secondary phase (forsterite) providing mechanical strength. This composite structure allows simultaneous achievement of low permittivity (ε ≤ 5.8) and high strength (flexural strength ≥ 200 MPa) by combining materials with complementary properties.
Solution Approach 2:
The patent creates local quality differences by forming a coating layer with a different composition than the base material. The coating layer has specific chemical composition ratios (SiO2: 20-40 mass%, MgO: 30-40 mass%, ZnO: 10-30 mass%) that differ from the base glass ceramic, providing localized stress management and crack resistance while maintaining overall low permittivity.
2Length of stationary object
If material composition is optimized for low permittivity, then permittivity decreases, but Q-value cannot be improved simultaneously
Solution Approach 1:
The patent employs a composite structure where the main phase (indialite or cordierite) provides low permittivity and the forsterite secondary phase contributes to high Q-value. The specific phase composition ratio (secondary phase 5-30 mass%) is optimized to simultaneously achieve low permittivity (ε ≤ 5.8) and high Q-value (≥ 1000 at 1 GHz), resolving the trade-off between these two electromagnetic properties.
Solution Approach 2:
The patent changes physical and chemical parameters of the glass ceramic composition, specifically controlling the ratios of SiO2, MgO, ZnO, and other oxides, as well as the grain size distribution and phase composition. By adjusting these parameters within specific ranges, the patent achieves the dual optimization of low permittivity and high Q-value that cannot be obtained with conventional single-phase materials.
3Strength
If grain size is increased to improve strength, then strength increases, but Q-value decreases and permittivity increases
Solution Approach 1:
The patent applies local quality by creating a coating layer with specific composition on the grain surfaces. This coating layer (with SiO2: 20-40 mass%, MgO: 30-40 mass%, ZnO: 10-30 mass%) provides localized stress management and crack resistance, allowing the use of larger grains (average size 0.35-2.0 μm) for strength improvement without the proportional increase in permittivity and decrease in Q-value that would occur in uniform bulk material.
Solution Approach 2:
The patent uses a composite grain structure where larger grains (0.35-2.0 μm average size) provide mechanical strength, while the forsterite secondary phase (5-30 mass%) dispersed within and on the grains maintains high Q-value. The coating layer further enhances this by providing stress management at grain boundaries, enabling simultaneous achievement of high strength (≥ 200 MPa) and high Q-value (≥ 1000).
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 solution effectively achieves low permittivity, high strength, and high Q-value, enhancing the performance of electronic components for high-frequency applications by managing thermal expansion coefficients and crack resistance through the specific phase compositions and coating layer thickness.
Implementation Method 1
the cordierite phase and the indialite phase, particularly of the indialite phase, have relatively low thermal expansion coefficient compared to the forsterite phase. Thus, since the coating layer with relatively high thermal expansion coefficient covers the main phase grain with relatively low thermal expansion coefficient, stress is kept applied on the main phase grain.
Data Source
AI summary
An electronic component includes a glass ceramic sintered bod. The glass ceramic sintered body includes a main phase grain including at least one of a cordierite phase and an indialite phase, and a coating layer including a forsterite phase covering the main phase grain.