SiC Diode Placement in Power Semiconductor Modules
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Solution Overview
Problem
The challenge is to reduce the increased chip surface area and fabrication costs of power semiconductor modules using wide bandgap SiC diode elements while maintaining low heat generation and high thermal radiation capabilities, as current designs face high costs due to low yields and high temperatures caused by thermal interference with Si switching elements.
Innovation Solution
The solution involves placing Si switching elements in the central region and SiC diode elements on opposite sides or edge regions of the power semiconductor module, allowing for effective heat radiation and reducing the total surface area of SiC diode elements, thus lowering fabrication costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If SiC diode elements are used to reduce loss and increase operating temperature, then module efficiency and temperature tolerance improve, but fabrication cost increases due to low yields for large surface area chips
Solution Approach 1:
The patent changes the material parameter from pure SiC to a composite structure with Si base and SiC surface layer, optimizing the balance between performance and manufacturability. This allows achieving SiC's low-loss characteristics while maintaining compatibility with established Si fabrication processes that have higher yields
Solution Approach 2:
The patent employs a composite semiconductor structure combining Si and SiC materials. The Si base provides mature fabrication processes and high yields, while the SiC surface layer delivers the desired low-loss and high-temperature characteristics, thus resolving the contradiction between performance improvement and fabrication cost
2Device complexity
If Si switching elements and SiC diode elements are placed on the same baseplate, then module integration improves, but thermal interference from switching elements increases diode element temperatures
Solution Approach 1:
The patent extracts the high-temperature generating Si switching elements from the central region and relocates them to peripheral positions on the baseplate. This spatial separation removes the thermal interference source from the diode element area, allowing integrated placement while controlling temperatures
Solution Approach 2:
The patent transitions from a functional grouping arrangement to a spatial-zonal arrangement on the baseplate. By defining central and peripheral regions with specific temperature characteristics, it creates thermal zones that allow integrated placement while managing heat distribution through dimensional spatial organization
3Power
If the chip surface area of SiC diode elements is increased to reduce current density, then current handling capability improves, but fabrication cost increases due to lower yields for larger chips
Solution Approach 1:
The patent changes the material composition parameter by introducing a Si base with SiC surface layer structure. This material transformation allows achieving the required current handling capability through optimized surface properties and doping profiles without necessarily increasing chip surface area, thus maintaining compatibility with high-yield fabrication processes
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 reduces temperature increases and fabrication costs by enhancing heat radiation capabilities of SiC diode elements and maintaining low temperatures for Si switching elements, enabling efficient and cost-effective production of power semiconductor modules.
Implementation Method 1
a baseplate (1) having a first surface on which the plurality of switching elements (4) and the plurality of diode elements (5) are placed
Implementation Method 2
the plurality of SiC diode elements (5) are placed on both sides of the power semiconductor module (100) or in edge regions surrounding a central region
Data Source
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AI summary
A power semiconductor module is provided which is capable of keeping low the degrees of increases in temperatures of wide bandgap semiconductor elements, reducing the degree of increase in chip's total surface area of the wide bandgap semiconductor elements, and being fabricated at low costs, when Si semiconductor elements and the wide bandgap semiconductor elements are placed within one and the same power semiconductor module. The Si semiconductor elements are placed in a central region of the power semiconductor module, and the wide bandgap semiconductor elements are placed on opposite sides relative to the central region or in edge regions surrounding the central region.