SiC Power Module Wiring Geometry for Surge Voltage Reduction
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Solution Overview
Problem
High-speed switching in SiC power devices leads to increased surge voltage due to high current change rates, potentially damaging the devices and causing electromagnetic interference and reliability issues, necessitating a reduction in internal wiring self-inductance.
Innovation Solution
The power module design incorporates a configuration where the self-inductance of internal wiring is reduced by arranging external and internal wiring connection portions in a specific geometry, with plate-shaped facing portions facing each other at a predetermined interval, and using conductive plate-shaped connection metal members to cancel out self-inductance and reduce thermal resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high-speed switching elements (SiC devices) are used to improve switching speed and reduce switching loss, then switching efficiency is improved, but surge voltage increases due to high current change rates
Solution Approach 1:
The patent applies reverse-arranged plate-shaped facing portions that generate opposing magnetic fields to convert the harmful surge voltage into a beneficial effect. The facing portions are positioned to face each other with their normal directions opposite, creating magnetic fields that cancel each other out, thereby suppressing voltage surges while maintaining high-speed switching performance
2Loss of energy
If high-speed switching is implemented to reduce switching loss, then energy efficiency is improved, but electromagnetic interference increases
Solution Approach 1:
The patent converts electromagnetic interference into a beneficial effect by using the magnetic fields generated by the reverse-arranged facing portions to cancel each other out. This configuration suppresses EMI noise while maintaining the high-speed switching characteristics that reduce energy loss
3Device complexity
If conventional wiring configuration is used, then device complexity is low, but self-inductance is high causing voltage surges
Solution Approach 1:
The patent applies asymmetry by arranging the plate-shaped facing portions in reverse directions rather than symmetric configurations. This asymmetric arrangement creates opposing magnetic fields that cancel self-inductance effects, reducing voltage surges while maintaining relatively simple device structure
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 reduces surge voltage, minimizes electromagnetic interference, and enhances the reliability and efficiency of the power module by efficiently canceling out self-inductance and lowering thermal resistance.
Implementation Method 1
the self-inductance of internal wiring is reduced by arranging external and internal wiring connection portions in a specific geometry, with plate-shaped facing portions facing each other at a predetermined interval
Implementation Method 2
using conductive plate-shaped connection metal members to cancel out self-inductance and reduce thermal resistance
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A first power supply terminal P is provided with an internal wiring connection portion 31A, an upright portion 31B which is joined to the internal wiring connection portion 31A, an inclined portion 31C which is joined to the upright portion 31B and an external wiring connection portion 31D which is joined to the inclined portion 31C. A second power supply terminal N is provided with an internal wiring connection portion 32A, an upright portion 32B which is joined to the internal wiring connection portion 32A, an inclined portion 32C which is joined to the upright portion 32B and an external wiring connection portion 32D which is joined to the inclined portion 32C. The upright portion 31B of the first power supply terminal P and the upright portion 32B of the second power supply terminal N are arranged so as to face each other, with a predetermined interval kept therebetween.