Core-Shell Varistor Material for Low-Temperature Sintering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current varistor materials, such as SrTiO3, SiC, ZnO, Fe2O3, and BaTiO3, face limitations in surge absorbency and electrical properties, particularly requiring high temperatures for grain-boundary insulating layer production and resulting in unsuitable high-voltage components with inferior electrical properties.
Innovation Solution
A core-shell microstructure varistor composition comprising a conductive or semi-conductive cored-structure wrapped with a glass shelled-structure, allowing for lower temperature sintering (600° C. to 1,100° C.) and precise control of electrical properties through adjustments in grain size, insulating layer thickness, and electrode parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional grain-boundary insulating layers are used (crystalline phases like α-Bi2O3, Na2O, or SrTiO3), then surge absorbent ability is achieved, but sintering temperature must be relatively high
Solution Approach 1:
The patent changes the fundamental parameter of the insulating layer material from crystalline phases to glass material, which fundamentally alters the sintering temperature requirement. Glass-based insulating layers enable low-temperature sintering (600-1100°C) while maintaining effective surge absorbent ability through the glassy phase's inherent insulating and binding properties.
Solution Approach 2:
The patent employs a composite material system where glass material serves as the insulating layer matrix, potentially combined with other oxides to optimize both electrical insulation and chemical stability. This composite approach allows achieving desired electrical properties at lower sintering temperatures compared to pure crystalline phases.
2Reliability
If varistors are made from ZnO, TiO2, SnO2 or SrTiO3 with crystalline grain-boundary insulating layers, then surge absorbent ability is achieved, but production requires high sintering temperature
Solution Approach 1:
The patent fundamentally changes the material parameter from crystalline to glass-based insulating layers, which transforms the manufacturing process by enabling low-temperature sintering. This parameter change simplifies production by reducing energy consumption, shortening cycle times, and allowing the use of less expensive equipment while maintaining effective surge protection.
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
Enables the production of varistors with improved electrical properties, including higher breakdown voltage and reduced leakage current, while meeting the demands of high-frequency applications with enhanced surge absorbency and reduced production costs.
Implementation Method 1
a shelled-structure made from a glass material to wrap the cored-structure
Implementation Method 2
varistors constructed from the disclosed material composition can be produced through sintering the material composition at a relatively lower temperature, which is typically between 600° C. and 1,100° C.
Data Source
AI summary
A material composition having a core-shell microstructure suitable for manufacturing a varistor having outstanding electrical properties, the core-shell microstructure of the material composition at least comprising a cored-structure made of a conductive or semi-conductive material and a shelled-structure made from a glass material to wrap the cored-structure, and electrical properties of the varistors during low temperature of sintering process can be decided and designated by precisely controlling the size of the grain of the cored-structure and the thickness and insulation resistance of the insulating layer of the shelled-structure of material composition.