Power Electronics Assembly With Insulated Bolt-Sleeve Thermal Coupling
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Solution Overview
Problem
Power electronics assemblies used in electric vehicles generate significant heat, leading to thermal expansion and potential damage to components, as existing solutions do not effectively manage heat dissipation and electrical insulation between circuit boards.
Innovation Solution
A power electronics assembly design that couples a composite material substrate to an insulated metal substrate using a bolt with an electrically conductive sleeve, where an electrically insulating sleeve separates the bolt from conductive elements, providing a stand-off spacing and clamping force to thermally couple elements to a heat sink while maintaining electrical connectivity and insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If power electronics elements are mounted on a circuit board without effective thermal management, then electrical connectivity is maintained, but heat dissipation is insufficient leading to thermal expansion and component damage
Solution Approach 1:
The circuit board is divided into two separate substrates (first substrate and second substrate) that are thermally coupled through a heat sink. The power electronics elements on the first substrate are thermally managed separately from the elements on the second substrate, allowing independent thermal paths and preventing thermal expansion damage to sensitive components.
Solution Approach 2:
A heat sink acts as an intermediary thermal management component between the power electronics elements and the environment. The heat sink receives thermal energy from the power electronics elements through thermal coupling and dissipates it to the environment, preventing excessive heat accumulation and thermal expansion of components.
2Temperature
If a bolt is used to couple substrates for thermal management, then heat dissipation is improved, but electrical insulation between conductive elements is compromised
Solution Approach 1:
The bolt is extracted from direct contact with conductive elements by introducing insulating sleeves. The first insulating sleeve is positioned between the bolt and the first conductive element, and the second insulating sleeve is positioned between the bolt and the second conductive element, preventing electrical short circuits while maintaining the bolt's thermal management function.
Solution Approach 2:
Insulating sleeves act as intermediary components between the conductive bolt and conductive elements. These sleeves electrically isolate the bolt from the conductive elements while allowing the bolt to maintain thermal coupling between substrates, resolving the conflict between electrical insulation and thermal management.
3Strength
If circuit boards are clamped together for mechanical stability, then structural integrity is improved, but thermal expansion causes misalignment and potential damage
Solution Approach 1:
The mechanical coupling system is segmented into multiple independent coupling points (first bolt and second bolt positioned at different locations). This segmentation allows each coupling point to independently accommodate local thermal expansion variations, maintaining overall alignment stability while providing strong mechanical coupling.
Solution Approach 2:
The system accommodates thermal expansion by allowing positional parameters of the substrates to change dynamically. The insulating sleeves and spaced-apart configuration allow for thermal movement while maintaining electrical insulation and mechanical stability, effectively managing thermal expansion without compromising alignment.
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 design effectively manages heat dissipation and protects components from thermal expansion by maintaining electrical insulation and connectivity, ensuring reliable operation in high-temperature environments.
Implementation Method 1
the IMS 103 is coupled to a heat sink 102
Implementation Method 2
effectively manages heat dissipation
Implementation Method 3
An electrically insulating sleeve 111 surrounds the bolt 106... The electrically insulating sleeve 111 electrically insulates conductive elements on the CMS 101 from the bolt 106
Implementation Method 4
a bolt 106 for coupling a composite material substrate (CMS) 101 to an insulated metal substrate (IMS) 103
Implementation Method 5
clamping force to thermally couple elements to a heat sink
Implementation Method 6
The power assembly 100 is configured to clamp an electrically conductive sleeve 115 between the CMS 101 and the IMS 103 to electrically couple elements on the CMS 101 to elements on the IMS 103
Implementation Method 7
These power assemblies may comprise elements of the power electronics that evolve considerable heat when in use... the IMS may expand and/or move in use due to thermal expansion
Data Source
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AI summary
A power electronics assembly for an electric motor controller is disclosed. The power electronics assembly comprises an insulated metal substrate, a composite material substrate,and a bolt comprising a bolt head and a bolt shaft for mechanically coupling the composite material substrate to the insulated metal substrate. The power electronics assembly also comprises an electrically conductive sleeve configured to be held between a first electrical contact carried by the insulated metal substrate and a second electrical contact carried by the composite material substrate and the bolt is configured to clamp the composite material substrate to the insulated metal substrate to force the electrically conductive sleeve against the first electrical contact and the second electrical contact.