PTC heating device and method for its manufacture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing PTC heating devices face challenges in achieving efficient electrical insulation and heat extraction while maintaining mechanical integrity, especially in high-voltage motor vehicle applications, where ceramic plates may fracture under mechanical stress and require effective electrical insulation.
Innovation Solution
A PTC heating device with a multilayer insulation comprising a film and a brown compact made of non-sintered ceramic particles, where the binding agent is partially removed to allow deformation and improve dielectric strength, and the insulation is designed to cover the PTC element and conductor tracks, enhancing electrical insulation and heat extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a ceramic plate is used for insulation, then electrical insulation is ensured, but mechanical stress causes fracture
Solution Approach 1:
The patent uses a composite insulation structure consisting of a plastic film layer and a ceramic particle layer bound with binding agent. This composite material combines the electrical insulation properties of ceramic with the mechanical flexibility and fracture resistance of plastic, resolving the contradiction between ensuring electrical insulation and preventing mechanical fracture.
2Reliability
If a two-layer insulation with ceramic plate is used, then electrical insulation is ensured, but heat extraction efficiency decreases
Solution Approach 1:
The patent applies different materials with different properties to different locations: the plastic film provides flexibility and structural integrity, while the ceramic particle layer provides electrical insulation. This local differentiation allows heat to be extracted efficiently through the plastic regions while maintaining insulation where ceramic particles are present, resolving the contradiction between electrical insulation and heat extraction efficiency.
3Reliability
If insulation thickness is increased, then electrical insulation is improved, but device complexity and size increase
Solution Approach 1:
The patent achieves high electrical insulation with thin profile by using a composite structure where ceramic particles provide insulation properties in a concentrated manner, while the plastic matrix provides structural support. This allows sufficient insulation performance without increasing overall thickness or structural complexity, resolving the contradiction between improved electrical insulation and reduced device complexity.
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 improved dielectric strength, thermal conductivity, and mechanical flexibility, ensuring efficient heat extraction and electrical insulation with a CTI value of >1000, suitable for high-voltage motor vehicle applications, while maintaining a thin profile and preventing ceramic fracture.
Implementation Method 1
The mass contains ceramic particles that are highly conductive... good heat extraction of the heat generated by the PTC element... thermal conductivity
Implementation Method 2
electrical insulation must be ensured under all circumstances due to the use of the PTC heating device in a high-voltage motor vehicle... dielectric strength... CTI value of >1000
Data Source
AI summary
A PTC heating device exhibits a good degree of efficiency while providing good electrical insulation of the device's PTC element. The insulation of the PTC heating device comprises a film and a layer that is bonded to the film and made of brown compact which comprises non-sintered ceramic particles. Also disclosed is a method in which ceramic particles are provided with a binding agent, and the mass thus produced is applied in a planar manner onto a film and bonded to the film. The multilayer insulation thus produced is placed around the PTC element and the conductor tracks, and the binding agent is subsequently removed, at least in part.