NTCR Sensor Aerosol Deposition Single-Step Sintering
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Solution Overview
Problem
The manufacturing of negative temperature coefficient resistor (NTCR) sensors is costly and labor-intensive due to the numerous steps required in existing methods, including multiple heat treatment processes, which complicates the production of high-quality sensors.
Innovation Solution
A method involving the formation of a mixture of uncalcined metal oxide powders into an aerosol, which is deposited onto a substrate and then treated at a single heat step below 1000 °C to form a spinel-based material, reducing the number of heat treatment steps and improving adhesion and density of the film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If classic ceramic manufacturing techniques with multiple heat treatment steps are used, then the quality and reliability of NTCR sensors are ensured, but the manufacturing complexity and cost increase significantly
Solution Approach 1:
The patent combines multiple heat treatment steps (calcination, sintering, and contact firing) into a single heat treatment step performed at approximately 850°C. This merging of processes reduces manufacturing complexity while maintaining sensor quality, as the single step simultaneously achieves particle densification, phase formation, and contact integration that traditionally required separate high-temperature steps
Solution Approach 2:
The single heat treatment step serves multiple functions: it acts as both a sintering step to densify the ceramic body and as a firing step to integrate the electrical contacts. This multi-functionality eliminates the need for separate high-temperature sintering and contact firing operations, reducing overall process complexity while ensuring reliable sensor performance
2Manufacturing precision
If multiple separate heat treatment steps are performed, then complete transformation to spinel phase and proper sintering are achieved, but the manufacturing time and energy consumption increase
Solution Approach 1:
The patent merges the sintering process and phase transformation step into a single heat treatment operation at approximately 850°C. This eliminates the need for separate high-temperature sintering followed by lower-temperature phase transformation, reducing total manufacturing time while achieving complete spinel phase formation and proper densification simultaneously
Solution Approach 2:
The patent optimizes the heat treatment temperature to approximately 850°C, which is sufficient to achieve both complete transformation to the desired spinel phase and adequate sintering. This parameter optimization eliminates the need for higher temperature steps followed by cooling and re-heating, significantly reducing manufacturing cycle time while maintaining phase purity
3Manufacturing precision
If traditional multi-step processes with high temperature sintering are used, then dense films with good adhesion are obtained, but the manufacturing cost and effort increase
Solution Approach 1:
The patent combines the sintering process with the formation of the final sensor structure in a single heat treatment step at approximately 850°C. This eliminates the need for separate high-temperature sintering operations and subsequent processing steps, reducing manufacturing effort while achieving dense films with excellent adhesion properties through the integrated process
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
This approach significantly reduces production costs and effort while maintaining the quality of NTCR sensors by simplifying the process to a single multifunctional temperature treatment, enhancing adhesion, and achieving long-term stability of the sensors.
Implementation Method 1
forming an aerosol from said mixture and said carrier gas and accelerating said aerosol in a vacuum towards a substrate arranged in a deposition chamber; forming a film of the uncalcined powder of said mixture on said substrate
Implementation Method 2
accelerating said aerosol in a vacuum towards a substrate arranged in a deposition chamber
Implementation Method 3
transforming the film into a layer of spinel-based material by applying a heat treatment step
Implementation Method 4
transforming the film into a layer of spinel-based material by applying a heat treatment step below 1000 °C
Data Source
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AI summary
The present invention relates to a method of producing a negative temperature coefficient resistor (NTCR) sensor, the method comprising the steps of: providing a mixture comprising uncalcined powder and a carrier gas in an aerosol-producing unit, with the uncalcined powder comprising metal oxide components; forming an aerosol from said mixture and said carrier gas and accelerating said aerosol in a vacuum towards a substrate arranged in a deposition chamber; forming a film of the uncalcined powder of said mixture on said substrate; and transforming the film into a layer of spinel-based material by applying a heat treatment step.