What is the difference between IGBT and MOSFET?
Date:2025-06-18
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IGBT (Insulated Gate Bipolar Transistor) and MOSFET (Metal Oxide Semiconductor Field Effect Transistor) are the two core devices in the field of power semiconductors, and their essential differences stem from the differentiated design of their physical structures, working principles, and target application scenarios. The following comparative analysis is conducted from four dimensions: device principles, electrical characteristics, packaging technology, and application scenarios:
1、 Device principle: Fundamental differences in carrier types
Structural characteristics of IGBT
Composite device: composed of MOSFET (gate controlled) and bipolar junction transistor (BJT), combining the voltage driving characteristics of MOSFET and the low conduction voltage drop advantage of BJT.
PNPN four layer structure: By injecting minority carriers (holes) to form a conductivity modulation effect, the conduction resistance (Rce) is significantly reduced, but the switching speed is sacrificed.
Structural characteristics of MOSFET
Monopolar devices: rely solely on majority carriers (electrons) for conductivity, without minority carrier storage effects, and have extremely fast switching speeds (nanosecond level).
Metal oxide semiconductor structure: By regulating the channel on/off through gate voltage, the input impedance is extremely high (above 10 ¹² Ω), and the driving power consumption approaches zero.
2、 Electrical characteristics: a direct reflection of performance trade-offs
Parameter IGBT MOSFET
Low conduction loss (Rce<1m Ω· cm ²) in (Rds (on)>1m Ω· cm ²)
Slow switching speed (μ s level) and fast switching speed (ns level)
High switch loss (tail current effect) and low (no tail current)
High voltage resistance (>600V, up to 6500V), medium voltage (<3000V)
The safe working area is wide (with strong short-circuit resistance) and narrow (requiring complex protective circuits)
Temperature coefficient positive (parallel current sharing required) negative (automatic current sharing)
3、 Packaging technology: adapted to the needs of different power levels
The evolution of IGBT packaging
Modular packaging: such as Infineon PrimePack and Mitsubishi DV70 series, achieve high current output (>1000A) through multi chip parallel connection, integrate temperature sensors and drive circuits, and adapt to industrial frequency converters and electric vehicle main drives.
Crimp packaging: such as SKiiP technology, using pressure connection instead of welding to eliminate the risk of thermal fatigue of solder joints, with a lifespan of up to 10 ⁶ hours, used for rail transit and high-voltage direct current transmission.
The packaging trend of MOSFET
Surface mount (SMD): such as TOLL and LFPAK packages, with a 50% reduction in volume and parasitic inductance<1nH, supporting high-frequency applications of GaN devices (>1GHz).
3D integrated packaging: Vertically interconnect chips through silicon via (TSV) technology, reducing parasitic inductance by 80%, used for 5G base station power supply and fast charging heads.
4、 Application scenario: trade-off between power and frequency
The main battlefield of IGBT
High power industries, such as metallurgy and mining frequency converters (>1MW), require a voltage tolerance of over 1000V, and IGBT modules are 30% more cost-effective than MOSFETs.
Electric vehicles: Main drive inverter (>100kW), IGBT module efficiency>98%, SiC MOSFET only shows advantages on the 800V platform.
New energy: Photovoltaic inverters, wind power converters, IGBT's surge resistance is twice as high as MOSFET's.
Advantages of MOSFET in various fields
High frequency power supply: such as mobile phone fast charging (>100W), GaN MOSFET switching frequency up to MHz level, with a volume reduction of 60%.
Precision control: such as drone motor drive (<1kW), MOSFET's nanosecond response speed enables speed regulation resolution to reach 0.1%.
Special scenarios: aerospace (diamond MOSFET temperature resistance>500 ℃), medical equipment (low leakage MOSFET meets FDA standards).
5、 Technological Evolution: Dual Breakthrough in Materials and Structures
The future direction of IGBT
SiC based IGBT: Combined with the high critical field strength characteristics of SiC, the withstand voltage is increased to over 10kV, suitable for smart grids and ship propulsion.
RC-IGBT (reverse conduction type): Integrated reverse freewheeling diode, reducing module size by 30% and cost by 20%.
The Innovation Path of MOSFET
GaN on Si: Heterogeneous integration of GaN on 8-inch silicon wafers reduces costs by 50%, promoting the popularization of 5G communication modules.
Two dimensional materials: atomic thickness materials such as graphene and molybdenum disulfide (MoS ₂), exploring future ultra micro MOSFETs.
conclusion
The essential difference between IGBT and MOSFET is that they exchange switching speed for voltage resistance and conduction loss for driving simplicity. IGBT is like a "heavy-duty truck" in the field of power electronics, dominating high-power scenarios such as industry and automobiles with high voltage resistance and high current characteristics; MOSFET is like a "race car", dominating precision fields such as consumer electronics and communications with high frequency and efficiency characteristics. In the future, with the popularization of SiC/GaN materials and the maturity of 3D packaging technology, both will continue to expand their performance boundaries, jointly promoting the evolution of power electronic systems towards higher efficiency and intelligence.