IGBT Gate Resistor Timing to Reduce Tail Current
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Solution Overview
Problem
Existing IGBTs face challenges in achieving fast-switching operations due to tail current flow caused by residual carriers, and existing solutions like introducing crystal defects increase leakage current.
Innovation Solution
A semiconductor device with a drive circuit that includes resistors of different resistance values connected to IGBT cells, allowing for controlled timing of gate signal transitions to reduce residual hole carrier density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the IGBT structure and control circuit are significantly changed to reduce tail current, then switching speed is improved, but device complexity increases
Solution Approach 1:
The IGBT is divided into multiple cell groups, each with independent gate control. This segmentation allows different turn-off timings for different cell groups, reducing tail current and improving switching speed while maintaining a relatively simple overall device structure.
Solution Approach 2:
The first gate is turned off before the second gate in a preliminary action sequence. This preliminary turn-off of the first gate reduces the hole carrier density before the second gate turns off, thereby reducing tail current and enabling faster switching without complex circuit modifications.
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 enables faster switching by reducing tail current and promoting carrier recombination, improving switching speed without increasing leakage current.
Implementation Method 1
a first resistor comprising a first electrode electrically connected to the gate control circuit and a second electrode; and a second resistor comprising a first electrode electrically connected to the gate control circuit and a second electrode that is not electrically connected to the second electrode of the first resistor; wherein the second resistor comprises a resistance value greater than that of the first resistor
Implementation Method 2
IGBTs (Insulated Gate Bipolar Transistor) are capable of low ON voltage by the effect of conductivity modulation
Implementation Method 3
it has been known to introduce a crystal defect in a drift region and capture a residual carrier by the carrier trap effect
Data Source
AI summary
A semiconductor device according to one or more embodiments may include a drive circuit comprising: a gate control circuit that generates a gate control signal; a first resistor comprising a first electrode electrically connected to the gate control circuit and a second electrode; and a second resistor comprising a first electrode electrically connected to the gate control circuit and a second electrode that is not electrically connected to the second electrode of the first resistor; wherein the second resistor comprises a resistance value greater than that of the first resistor; an IGBT circuit comprising: a first IGBT cell electrically connected to the second electrode of the first resistor; and a second IGBT cell electrically connected to the second electrode of the second resistor.