Thermal Diode for Vehicle PCB Cooling
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Solution Overview
Problem
Existing cooling systems for electronic components in vehicles, such as ECUs, face inefficiencies in heat transfer due to suboptimal thermal interface materials and coefficients of thermal expansion, leading to reduced cooling effectiveness.
Innovation Solution
A thermal diode with dual-component materials of varying thermal conductivity and expansion coefficients, combined with a coolant and a heat sink, is used to enhance heat transfer by compressing thermal interface layers and increasing surface contact, allowing for active or passive cooling without additional power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cooling systems use standard thermal interface materials, then the cooling system is simple to implement, but heat transfer efficiency is reduced due to suboptimal thermal conductivity and thermal resistance
Solution Approach 1:
The thermal diode is constructed from two different materials with distinct thermal properties (different thermal conductivities and coefficients of thermal expansion). This composite structure enables the device to achieve superior heat transfer efficiency by optimizing thermal conduction paths while maintaining the ability to compress interface layers under thermal stress.
Solution Approach 2:
Different regions of the cooling apparatus have different material properties - the first and second portions of the thermal diode use materials with specific thermal conductivities and expansion coefficients tailored to their local function. This allows optimization of heat transfer at critical interfaces while managing thermal expansion differences.
2Reliability
If thermal interface layers are made thinner to reduce thermal resistance, then heat transfer improves, but mechanical stress and potential failure increase
Solution Approach 1:
The coefficient of thermal expansion is used as a key parameter to resolve the contradiction. By selecting materials with appropriate expansion coefficients, the thermal diode generates compressive force on the interface layers during temperature cycles, reducing thermal resistance while simultaneously preventing interface delamination and reducing mechanical stress through controlled expansion/contraction behavior.
Solution Approach 2:
The invention exploits differential thermal expansion between the two materials in the thermal diode. As temperature changes, the materials expand and contract at different rates, creating a mechanical compression effect on the thermal interface layers. This dynamically reduces thermal resistance during operation while the controlled expansion prevents excessive mechanical stress accumulation.
3Reliability
If active cooling methods like forced convection are used, then cooling effectiveness improves, but power consumption increases
Solution Approach 1:
The thermal diode is a passive device that automatically regulates heat flow based on temperature gradients and material properties. It requires no external power source or active control mechanisms - the differential thermal expansion and thermal conductivity of its materials self-regulate the cooling effect, eliminating the need for energy-consuming fans or pumps while maintaining effective cooling.
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 configuration improves heat transfer efficiency by reducing thermal resistance and mechanical stress, achieving more effective cooling than conventional methods, including air forced convection, and can function with or without recirculated coolant.
Implementation Method 1
at least one layer is being compressed to a thinner layer thickness by expansion of the thermal diode and/or the component in a heated state of the thermal diode and/or of the component
Implementation Method 2
The thermal diode comprises two zones, each comprising at least one of two component materials, wherein each material has a different thermal conductivity W/mK
Data Source
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AI summary
The invention concerns a cooling method, especially for a car and specifically an apparatus (16) for cooling a component (3), especially a component (3) on a printed circuit board (10) for a vehicle, characterized in that the apparatus comprises a thermal diode (1) for transfer of heat from the component (3) to a heat sink (4).