Triple-Gate IGBT Switching Control for Lower Turn-On Loss

Solution Overview

Problem

Existing insulated gate bipolar transistors (IGBTs) face challenges in reducing turn-on loss while maintaining low on-voltage and switching loss, and are prone to erroneous ignition due to parasitic capacitance and gate voltage fluctuations during switching.

Innovation Solution

A semiconductor module with a triple gate structure, where each gate electrode is independently controlled, and a third gate electrode is driven during turn-on to reduce turn-on loss, and its off-voltage is transitioned to multiple levels to prevent erroneous ignition and conduction loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If channel density is increased to reduce on-voltage, then on-voltage decreases, but short-circuit resistance decreases making it difficult to reduce turn-on loss

Engineering Contradiction:

Improveon-voltageVSAvoidturn-on loss

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The gate electrode is divided into three independent gate electrodes (first, second, and third gate electrodes), allowing separate control of turn-on and turn-off processes. The third gate electrode is specifically activated during turn-on to reduce turn-on loss, while the first and second gate electrodes control the main switching operation, achieving independent optimization of turn-on and turn-off characteristics.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If gate voltage transitions are not managed during switching, then control is simplified, but erroneous ignition occurs due to parasitic capacitance and voltage fluctuations

Engineering Contradiction:

Improvecontrol complexityVSAvoiderroneous ignition prevention

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The third gate electrode is activated in advance during the turn-on period before the main switching operation, preparing the channel to reduce turn-on loss. Additionally, gate voltage transitions are proactively managed by controlling the timing and level of voltage applied to the third gate electrode, preventing erroneous ignition before it can occur.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The drive device monitors the switching state and dynamically adjusts the gate voltage transitions of the three gate electrodes accordingly. By providing feedback control on voltage transitions, the system prevents erroneous ignition caused by parasitic capacitance effects while maintaining optimal switching performance.

Inventive Principle:

Principle #23Feedback

3Loss of energy

If triple gate structure with independent control is implemented, then turn-on loss and conduction loss are reduced, but device complexity increases

Engineering Contradiction:

Improveturn-on loss and conduction lossVSAvoidgate electrode structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The gate electrode is divided into three independent gate electrodes (first, second, and third gate electrodes), allowing separate control of turn-on and turn-off processes. The third gate electrode is specifically activated during turn-on to reduce turn-on loss, while the first and second gate electrodes control the main switching operation, achieving independent optimization of turn-on and turn-off characteristics.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12563759B2Semiconductor module

Publication Date: 2026.02.24 KK TOSHIBA

AI summary

A voltage of a third gate electrode of a first semiconductor device transitions from a first off-voltage that is not more than a threshold voltage to a second off-voltage lower than the first off-voltage during a period from when a pulse signal for turning off a first gate electrode and a second gate electrode of the first semiconductor device is input to a drive device to when any one of a first gate electrode, a second gate electrode, and a third gate electrode of a second semiconductor device reaches an on-voltage.