IGBTs, or Insulated Gate Bipolar Transistors, are a type of power semiconductor device used for switching and amplifying electrical power in various electronic systems. They are widely used in applications such as motor control, renewable energy systems, industrial equipment, and power supplies due to their high efficiency and fast switching capabilities.

IGBTs are primarily classified as automotive qualified or industrial qualified based on their applications and are offered in both discretes and modules.

These types of IGBTs cater to diverse application requirements, offering varying trade-offs between switching speed, conduction losses, blocking voltage, and ruggedness. Selecting the right types of IGBT is essential for optimizing the performance and efficiency of power electronic systems.

From a multitude of packages, IGBT devices are available from 300 V onwards in discrete designs to power modules supporting till 6500 V. Current-carrying capability of a single transistor spans a range from a few amps to several kilo-amps. Besides the well-established TO-package series, SMD components are available, accompanied by power modules for the highest power demand.

IGBTs classification:

IGBTs can be classified based on various parameters such as packaging configuration, switching technology, packages, and structure. Here are some common classifications:

1. Based on packaging configuration:

IGBTs are commonly packaged in various forms to meet different application requirements. The diode and IGBT are implanted on the different dies in case of duo pack whereas, in case of RC IGBTs, IGBT and diode are implanted on the same die.

2. Based on switching technology:

There are two types of IGBT based on the switching technology:

a) Hard switching: In hard switching, the IGBT undergoes rapid transitions in voltage and current between its on and off states during each switching cycle. This mode of operation is commonly used in applications where the switching frequency is moderate and the power loss during the transitions is a crucial consideration.

Applications: Motor drives, UPS (Uninterruptible Power Supplies), and Industrial inverters.

b) Soft switching: In soft switching, the transitions of the IGBT between its on and off states are carefully controlled to minimize the switching losses. This is achieved by synchronizing the device's switching with the circuit's resonant behaviours allowing for smoother transitions by implementing the techniques such as Zero Voltage Switching (ZVS) and Zero current switching (ZCS).

Applications: High-frequency power converters, induction heating systems

3. Based on packages:

IGBTs can be classified based on their packaging, which plays a crucial role in their thermal management, electrical performance, and ease of installation. The two types of IGBT based on the packages are:

  • Discrete IGBTs
  • IGBT Modules

3.1 Discrete IGBTs

Discrete IGBTs are individual IGBT chips that are typically housed in a standard package such as:

TO-220: A smaller through-hole package, suitable for lower power applications such as consumer electronics and small inverters.

TO-247: This is a popular through-hole package, offering robust construction and high-power handling capability. It is commonly used in industrial motor drives and power supply applications.

DPAK(TO-252): It is a type of surface mount package commonly used for power transistors and voltage regulators. They handle relatively high levels of power dissipation while occupying minimal PCB area.

D2PAK (TO-263): Surface mount package with a large thermal pad, often used in space-constrained applications such as compact power supplies and motor control.

Discrete IGBTs have some advanced features such as

a) Kelvin emitter configuration

b) Hybrid IGBTs

a) Kelvin emitter configuration:

TO-247 4pin package has an extra connection to the IGBT’s emitter, labeled E2 in Figure 5. This point shall be connected to the gate driver as shown in Figure. 5. Also known as Kelvin emitter terminal, this pin is not subject to the attenuation coming from the power loop. The current coming from the IGBT’s collector is solely conducted by the power emitter lead E1.

The Kelvin emitter configuration in discrete IGBTs offers several advantages that contribute to improved performance, reliability, and thermal management as they have lower parasitic inductance that reduces the voltage overshoot.

b) Hybrid IGBTs:
Use of a Schottky barrier diode as freewheeling diode co-packed with IGBT allows to extend capabilities of IGBT and enables significant reduction in Eon and overall switching losses. Freewheeling SiC Schottky barrier diodes significantly reduces switching losses at almost unchanged dv/dt and di/dt values.

These will improve efficiency and switching speed.

3.2 IGBT Modules:

IGBT modules integrate multiple IGBT chips, freewheeling diodes, and sometimes other components such as gate drivers, temperature sensors, and snubbers into a single package. IGBT modules are classified as below:

IGBT power modules comprises in different product families, configurations, current ratings as well as IGBT chip generations for an almost infinite number of applications. The well-known 62 mm, Easy and Econo families, IHM / IHV B-series, PrimePACK™ and XHP™ power modules are all equipped with the latest IGBT technologies. They come in chopper, dual, PIM, fourpack, sixpack, twelvepack, 3-level, booster or single switch configuration.

IGBT modules cover a range from only hundreds of watts to several megawatts. General purpose drives, traction, servo-units and renewable energy applications like solar inverters or wind applications benefit from the outstanding performance, efficiency and longevity of these highly reliable products.

IGBT modules are also available with pre-applied thermal interface material (TIM) for a reproducible thermal performance of power electronic applications. In addition, IGBT modules can be mounted with the help of PressFIT pins for a solder-less and lead-free mounting of power modules.
Automotive qualified IGBT module solutions are also available to support the designer's efforts in hybrid and electric mobility.

4. Based on structures:

The IGBT structure consists of several key components that collectively enable its operation as a power semiconductor device. The following are the IGBT structure:

Vertical Structures: Based on the vertical structures and doping concentrations the IGBTs are classified as the Non-punch through, Field stop and Reverse conducting IGBTs.

Gating structures:
Based on the type of gating structures IGBTs are classified as the planar, trench and Micro Pattern Trench (MPT) structures.