Ceramic Composition for Low Resistance PTC Thermistors
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Solution Overview
Problem
Current PTC thermistors face challenges in achieving low room temperature resistance and high temperature coefficient of resistance, limiting their application in consumer electronics and home appliances.
Innovation Solution
A ceramic composition comprising barium titanate powder, a rare-earth element material, and micro/nano silicate glass, where the micro/nano silicate glass is present in specific weight percentages to reduce resistance and enhance temperature coefficient of resistance, with a sintering process that forms a porous structure for improved electrical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional PTC thermistor materials and manufacturing methods are used, then the thermistor exhibits PTC effect and can serve as heater and thermal switch, but the room temperature resistance value is high and the temperature coefficient of resistance is limited
Solution Approach 1:
The patent modifies the chemical composition parameters of the ceramic material by incorporating specific ratios of barium titanate, rare-earth elements (such as neodymium, samarium, or europium), and silicate glass. This compositional parameter change enables the material to achieve low room temperature resistance while maintaining the PTC effect, resolving the contradiction between PTC performance and room temperature resistance.
Solution Approach 2:
The patent creates a composite ceramic material system combining barium titanate base material with rare-earth element additives and silicate glass modifiers. This composite structure allows the material to exhibit both the desired PTC characteristics and reduced room temperature resistance, as the rare-earth elements and glass phase work synergistically to modify the electrical properties while preserving the thermal switching functionality.
2Ease of manufacture
If conventional ceramic compositions are used, then the manufacturing process is simple, but the temperature coefficient of resistance cannot be sufficiently increased
Solution Approach 1:
The patent achieves high temperature coefficient of resistance through precise control of compositional parameters, specifically the content of rare-earth elements (0.1-5 wt%) and silicate glass (5-20 wt%). These parameter adjustments enable fine-tuning of the Curie temperature and resistance characteristics while maintaining compatibility with conventional sintering processes, thus improving manufacturing precision without significantly complicating the manufacturing procedure.
3Quantity of substance
If the composition is optimized for low room temperature resistance, then the electrical performance improves, but the structural stability may be compromised
Solution Approach 1:
The patent employs a composite ceramic system where barium titanate provides the structural framework and stability, while rare-earth elements and silicate glass phases contribute to electrical property modification. The silicate glass component specifically enhances structural stability and sinterability while the rare-earth elements control the electrical characteristics, creating a balanced composite material that achieves both low room temperature resistance and structural stability.
Solution Approach 2:
The silicate glass phase acts as an intermediary component that facilitates sintering and enhances structural stability during the manufacturing process. The glass phase fills intergranular spaces, binds crystalline grains, and provides structural support, thereby maintaining compositional stability while allowing the rare-earth elements to effectively modify the electrical properties for low room temperature resistance.
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 a low room temperature resistance value and high temperature coefficient of resistance, enhancing the electrical performance and structural strength of laminated ceramic electronic components.
Implementation Method 1
the cubic perovskite-type structure of the primary material can be semiconductorized by adding the first rare-earth element material so as to reduce the resistance value of the ceramic sintered body
Implementation Method 2
a ceramic sintered body obtained by sintering said ceramic composition
Data Source
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AI summary
This invention provides a ceramic composition, a ceramic sintered body, a laminated ceramic electronic component and a method for manufacturing the same. By adjusting the amount of the micro/nano silicate glass of the ceramic composition, the ceramic sintered body has a glass phase after sintering the ceramic composition, and has an appropriate porosity so as to provide pathways to supply sufficient oxygen. Therefore, the laminated ceramic electronic component comprising the ceramic sintered body has excellent properties of low room temperature resistance value and high temperature coefficient of resistance.