Power Semiconductor is a semiconductor device specifically designed to handle high voltage, high current, and efficient energy conversion. They convert electrical energy from one form to another by controlling the on/off of current, regulating voltage and frequency, and are widely used in fields such as energy management, industrial control, and new energy. They are the core components of modern power electronic systems.
1、 The core role of power semiconductors
Electric energy control:
Adjust voltage, current, and frequency to achieve the conversion between direct current (DC) and alternating current (AC) (such as inverters, rectifiers).
Control the transmission path and efficiency of electrical energy (such as switching power supplies, motor drives).
Energy saving and protection:
Reduce energy loss (such as switch loss, conduction loss).
Provide circuit protection functions such as overvoltage, overcurrent, and short circuit.
2、 Main types and characteristics
|Device Type | Typical Representative | Characteristics | Application Scenarios|
|Diode | Schottky diode, fast recovery diode | Unidirectional conduction, low conduction voltage drop, high-speed switch | Rectification and freewheeling circuit|
|MOSFET | SiMOSFET, SiCMOSFET | High frequency switch, low on resistance, suitable for medium and low voltage (<1000V) | Power adapter, electric vehicle motor drive|
|IGBT | Silicon based IGBT, SiCIGBT | High voltage (>1200V), high current, combined with the advantages of MOSFET and BJT | Industrial frequency converter, new energy inverter|
|Thyristor (SCR) | Unidirectional/Bidirectional Thyristor | High voltage resistance, high current, self conducting after triggering | AC voltage regulation, solid-state relay|
|Wide bandgap semiconductor | SiC, GaN devices | High frequency, high temperature resistance, low loss, efficiency 20% 30% higher than silicon devices | 5G base station, fast charging for electric vehicles|
3、 Key performance indicators
Breakdown Voltage: The maximum voltage that a device can withstand (such as 650V, 1200V).
On resistance (Rds (on)): The resistance value in the conducting state, which directly affects energy loss.
Switching speed: The response time for switching between on and off states, which affects the efficiency of high-frequency applications.
Thermal characteristics: heat dissipation capability (such as thermal resistance Rth) and maximum operating temperature (SiC can reach over 200 ℃).
4、 Core application areas
New energy vehicles:
Electric drive system: IGBT/SiC module is used for motor controller (such as Tesla Model 3 using SiC MOSFET).
Charging pile: SiC devices improve charging efficiency, reduce volume and heat dissipation requirements.
Renewable energy:
Photovoltaic inverter: IGBT converts DC power from solar panels into AC grid connected power.
Wind power generation: The inverter controls the blade speed to synchronize with the grid.
Industrial control:
Inverter: Adjust motor speed to save 30% and 50% energy (such as elevators and air compressors).
Power supply: server power supply, welding equipment.
Consumer Electronics:
Fast charging adapter (GaN devices achieve small size and high power).
5、 Technological development trends
Material upgrade:
Silicon carbide (SiC): high temperature resistance, high-frequency characteristics suitable for electric vehicles and fast charging.
Gallium Nitride (GaN): High frequency and low loss, dominating consumer electronics and 5G base stations.
Modularization and Integration:
Encapsulating multiple devices into an intelligent power module (IPM) simplifies circuit design (such as Mitsubishi Electric's DIPIPM).
Digital control:
Integrated sensors and driver circuits, supporting real-time temperature monitoring and fault protection.
Cost reduction:
Breakthrough in SiC substrate manufacturing technology (such as mass production of 8-inch wafers), promoting popularization.
6、 Industry challenges
Thermal management: The heat dissipation problem is prominent under high power density, and packaging technology needs to be optimized (such as silver sintering process).
Reliability: The lifespan and stability requirements are strict under extreme working conditions (high temperature, vibration).
Supply chain: SiC/GaN materials rely on overseas manufacturers (Wolfspeed in the United States and Infineon in Germany).
Power semiconductors are the core technology of the energy revolution, and the upgrade from traditional silicon-based devices to wide bandgap semiconductors is driving the rapid development of electric vehicles, smart grids, and green energy. In the future, with material innovation and manufacturing process advancements, power semiconductors will become more efficient and compact, becoming a key support for achieving the goal of carbon neutrality.