IGBT Gate Runner Segmentation for di/dt Vibration Suppression
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Solution Overview
Problem
Conventional semiconductor devices, such as IGBTs, experience rapid di/dt during turn-on and turn-off events, leading to vibration in current and voltage, which generates radiation noise and complicates the driving circuit, especially with the need for additional components like shift resistors.
Innovation Solution
A semiconductor device with a MOS switching element, an edge termination structure, and a gate runner that includes a di/dt mitigating element, such as a capacitor or resistor, connected in parallel, to reduce the instantaneous rate of current change by distributing the gate input voltage and reducing the voltage rise time across IGBT cell groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the cell intervals are reduced to increase electron injection efficiency and enable greater collector current, then the productivity and performance are improved, but the di/dt becomes large causing vibration and radiation noise
Solution Approach 1:
The gate runner is divided into multiple independent gate terminals, each controlling a separate gate electrode group. This segmentation allows independent control of different cell groups, enabling sequential turning on/off to reduce di/dt and eliminate vibration while maintaining high collector current capability through parallel cell operation
Solution Approach 2:
The gate driving circuit uses shift resistors to sequentially delay the gate output signals to different gate terminals. This creates a periodic or sequential action where IGBT cells are turned on or off in stages rather than simultaneously, reducing the instantaneous di/dt and eliminating current and voltage vibration while maintaining overall high productivity
2Object-generated harmful factors
If shift resistors are added to sequentially delay gate signals and prevent vibration, then the harmful vibrations are reduced, but the device complexity increases
Solution Approach 1:
The gate runner is segmented into multiple independent gate terminals with separate gate electrodes for different cell groups. This segmentation allows the use of simple RC delay circuits formed by existing gate structures and added resistors, rather than requiring complex centralized control, thereby reducing overall device complexity while still achieving vibration suppression
Solution Approach 2:
Shift resistors are introduced as intermediary elements in the gate signal paths to different gate terminals. These resistors work with the inherent gate capacitances to create simple RC time constants that automatically provide sequential delay without requiring complex control logic, thus reducing driving circuit complexity while effectively preventing vibration
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
The solution effectively reduces the di/dt during turn-on and turn-off events, minimizing voltage and current vibrations, simplifying the driving circuit, and reducing gate driving power consumption without the need for additional components like shift resistors.
Implementation Method 1
a capacitor or a resistor that is connected in parallel to the capacitor
Data Source
AI summary
A semiconductor device, including a semiconductor substrate, an active region formed on the semiconductor substrate, and a gate runner disposed to surround the active region. The active region includes a first cell group in which a gate electrode of each cell is directly connected to the gate runner, and a second cell group in which a gate electrode of each cell is connected to the gate runner via a di/dt mitigating element. The di/dt mitigating element is a capacitor, a resistor connected in parallel to a capacitor, or an inverse-parallel-connected diode.