Planarly Stacked DC Terminals for Low-Inductance Power Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Stray inductance in power electric circuits using wide bandgap (WBG) transistors leads to efficiency reduction, voltage overshoots, electromagnetic interference, and circuit instability, particularly in electric vehicles and renewable energy converters.
Innovation Solution
A module with a planarly stacked DC terminal structure, where one DC terminal is sandwiched between two others, enhancing magnetic field cancellation and mutual inductance, and incorporating recesses and protrusions for electrical isolation and connection to the substrate, reducing stray inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional power terminal structures are used, then electrical connection is achieved, but stray inductance increases leading to voltage overshoots and electromagnetic interference
Solution Approach 1:
The patent implements a nested structure where one DC terminal is positioned inside another DC terminal, forming a concentric arrangement. This nesting configuration allows the magnetic fields generated by the two terminals to cancel each other out, significantly reducing stray inductance in the power circuit while maintaining reliable electrical connections.
Solution Approach 2:
The patent transitions from a planar or linear arrangement of terminals to a three-dimensional concentric configuration. By stacking terminals in the vertical dimension and arranging them in nested circles, the design creates magnetic field cancellation in multiple spatial dimensions, effectively reducing stray inductance without compromising electrical connectivity.
2Speed
If fast switching is implemented in WBG transistors, then switching speed improves, but voltage overshoots and electromagnetic interference worsen due to high di/dt
Solution Approach 1:
The nested terminal structure is designed in advance to counteract the harmful effects of fast switching. By pre-configuring the magnetic field cancellation geometry before switching events occur, the system proactively reduces voltage overshoots and electromagnetic interference that would otherwise be generated by high di/dt during fast switching operations.
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
Reduces total commutation loop stray inductance, minimizing voltage overshoots and electromagnetic interference, thereby improving circuit efficiency and reliability.
Implementation Method 1
One DC terminal of the power package for either the supply or the return line being at least largely encapsulated by the other DC terminal of the power package for the other of the supply or the return line, enhances magnetic field cancellation and increases the absolute value of the mutual inductance between them
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A module for an electric circuit and method of fabricating said module, wherein the module comprises a substrate comprising electric circuitry, and a Direct Current, DC, power package arranged for providing DC power to the electric circuitry by being electrically connected to the substrate, the DC power package comprises a first DC terminal and a second DC terminal, the second DC terminal being electrically isolated from the first DC terminal, wherein the first DC terminal comprises two planar electrical conductors and wherein the second DC terminal comprises one planar electrical conductor. The two planar electrical conductors of the first DC terminal and the one planar electrical conductor of the second DC terminal are planarly stacked with gaps between them, such that the one planar electrical conductor of the second DC terminal is sandwiched between the two planar electrical conductors of the first DC terminal reducing stray inductance in the module.