Paralleled Wide Band Gap Power Module for Even Current Sharing
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Solution Overview
Problem
Conventional power modules are inadequate for wide band gap devices due to issues with current sharing at high switching frequencies, material reliability at elevated temperatures, and mismatched inductances, which lead to uneven stresses and current overshoot during switching events.
Innovation Solution
A power module design with low inductance equalized current paths, using a 62mm base plate with low profile power contacts, internal gate & source kelvin interconnection substrate, and high-temperature materials for reliable operation up to 250°C, allowing for even current sharing and clean switching events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional power modules are used with multiple wide band gap devices in parallel, then high current capability is achieved, but current sharing becomes uneven and current overshoot occurs during switching events
Solution Approach 1:
The patent implements equipotentiality by designing equalized current paths with matched inductance values for each parallel device branch. The current paths are engineered to have identical electrical characteristics, ensuring that all paralleled wide band gap devices experience the same voltage and current conditions during switching events. This eliminates current overshoot and ensures uniform current sharing across all devices, directly resolving the technical contradiction between achieving high current capability and maintaining current sharing uniformity.
2Loss of energy
If high switching frequencies are used to reduce switching losses, then system efficiency is improved, but current overshoot and uneven stresses increase during switching events
Solution Approach 1:
The patent applies preliminary anti-action by pre-matching the inductance values of all current paths before switching events occur. The equalized current path design with identical inductance values is established during the module assembly stage, creating a balanced electrical environment that prevents current overshoot and uneven stresses during high-frequency switching events. This preliminary configuration counteracts the potential harmful effects of high-frequency switching, allowing the system to operate efficiently while maintaining switching event stability.
3Ease of manufacture
If standard power module packaging is used, then manufacturing simplicity is maintained, but material reliability deteriorates at elevated temperatures above 150°C
Solution Approach 1:
The patent applies parameter changes by modifying the operating temperature parameter from the conventional limit of 150°C to an extended range of 200-250°C. This is achieved through careful selection of high-temperature compatible materials for the substrate, encapsulant, and bonding wires, and by optimizing the thermal management design of the module packaging. The parameter change enables the power module to maintain material reliability and structural integrity at elevated temperatures while preserving the simplicity of standard power module manufacturing processes.
Data Source
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AI summary
A power module (100) with multiple equalized parallel power paths supporting multiple parallel bare die power devices (500) constructed with low inductance equalized current paths for even current sharing and clean switching events. Wide low profile power contacts (400) provide low inductance, short current paths, and large conductor cross section area provides for massive current carrying. An internal gate & source kelvin interconnection substrate (600) is provided with individual ballast resistors and simple bolted construction. Gate drive connectors (700) are provided on either left or right size of the module. The module is configurable as half bridge, full bridge, common source, and common drain topologies.