Thermistor Sintered Body Phases for Stable B Constant Control
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Solution Overview
Problem
Thermistor sintered bodies produced on an industrial scale often experience composition deviations, leading to unstable B constants, which affect their ability to accurately detect temperature across a wide range.
Innovation Solution
A thermistor sintered body comprising a Y2O3 phase and a YMnO3 or YCrO3 phase, with specific compositions of Cr, Mn, Ca, and Sr, and a balanced inclusion of unavoidable impurities and Y, ensures a stable B constant range of 10-25 K, even with composition deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a thermistor sintered body is produced on an industrial scale, then productivity is improved, but manufacturing precision deteriorates due to composition deviation
Solution Approach 1:
The invention changes the compositional parameters by specifying precise ranges for Cr (3-20 mol%), Mn (5-18 mol%), Ca (1-18 mol%), and Sr (1-25 mol%). By defining these parameter ranges and their interactions, the patent enables industrial production while maintaining stable B constants despite normal composition variations that occur at scale.
Solution Approach 2:
The invention uses a composite material system containing multiple elements (Cr, Mn, Ca, Sr, Y) in specific combinations. This composite approach allows the material to maintain stable electrical characteristics and B constants even when individual element compositions vary during industrial production, as the multiple components work together to compensate for deviations.
2Reliability
If the B constant is stabilized despite composition deviation, then reliability is improved, but device complexity increases due to multiple additive elements
Solution Approach 1:
The invention merges multiple additive elements (Cr, Mn, Ca, Sr) into a single integrated material system. Rather than using separate components or layers, all additives are combined within the thermistor sintered body structure, allowing them to work synergistically to stabilize the B constant while maintaining a relatively simple overall device structure.
Solution Approach 2:
The multiple additive elements serve multiple functions simultaneously: Cr and Mn control the base resistance and B constant, while Ca and Sr provide compositional buffering that compensates for production variations. This multi-functionality allows a single material composition to achieve both performance targets and production robustness without requiring additional device components.
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 provides a thermistor sintered body with a stable B constant, enabling accurate temperature detection despite composition variations, by dissolving Ca and Sr in the YMnO3 or YCrO3 phase, thereby maintaining consistent resistance characteristics.
Implementation Method 1
Ca and Sr are preferably dissolved in the YMnO3 phase or the YCrO3 phase
Implementation Method 2
The thermistor detects a temperature on the basis of a change in the resistance value
Data Source
AI summary
Provided is a thermistor sintered body which stably provides a desired B constant even if a composition deviation of an additive element has occurred. The thermistor sintered body-includes a Y2O3 phase and a YMnO3 phase, wherein a chemical composition of Cr, Mn, Ca and Y excluding oxygen includes Cr: 3 mol % or less (while including 0%), Mn: 5 to 18 mol %, Ca: 1 to 18 mol %, and Sr: 1 to 25 mol %, with the balance being unavoidable impurities and Y. In the thermistor sintered body, Ca and Sr may be dissolved in the YMnO3 phase.