Ximenkang IGBT moduleIt is a modular semiconductor product packaged by bridging IGBT (Insulated Gate Bipolar Transistor Chip) and FWD (Free Current Diode Chip) through a specific circuit; The packaged IGBT module can be directly applied to devices such as frequency converters and UPS uninterruptible power supplies, with characteristics such as energy saving, easy installation and maintenance, and stable heat dissipation; Currently, most of the products sold in the market are modular products of this type, and generally speaking, IGBT also refers to IGBT modules; With the promotion of energy-saving and environmental protection concepts, such products will become increasingly common in the market.
Ximenkang IGBT moduleThe function of the switch is to form a channel by applying a forward gate voltage, providing base current to PNP (formerly NPN) transistors to make IGBT conductive. On the contrary, applying a reverse gate voltage eliminates the channel, cuts off the base current, and turns off the IGBT. The driving method of IGBT is basically the same as that of MOSFET, only the input electrode N-channel MOSFET needs to be controlled, so it has high input impedance characteristics. After the channel of the MOSFET is formed, holes (minority carriers) are injected from the P+base into the N-layer to modulate the conductivity of the N-layer, reducing its resistance and allowing the IGBT to have a low on state voltage even at high voltages.
Ximenkang IGBT modulePrecautions during use
Due to the MOSFET structure of the IGBT module, the gate of the IGBT is electrically isolated from the emitter through a layer of oxide film. Due to the thin oxide film, its breakdown voltage generally reaches 20-30V. Therefore, gate breakdown caused by static electricity is one of the common reasons for IGBT failure.
Therefore, when using Ximenkang IGBT modules, the following points should be noted:
1. When using the module, try not to touch the drive terminal part with your hands. When it is necessary to touch the module terminal, first discharge the static electricity on the human body or clothing with a large resistor before touching it;
2. When connecting module drive terminals with conductive materials, please do not connect the module before the wiring is properly connected;
3. Try to operate with a well grounded base plate. Sometimes in applications, although the gate driving voltage is ensured not to exceed the rated voltage of the gate, the parasitic inductance of the gate connection and the capacitive coupling between the gate and collector can also generate oscillating voltages that damage the oxide layer. For this purpose, twisted pair cables are usually used to transmit drive signals to reduce parasitic inductance. Connecting a small resistor in series in the gate connection can also suppress oscillation voltage.
In addition, when there is an open circuit between the gate and emitter, if a voltage is applied between the collector and emitter, as the collector potential changes, due to leakage current flowing through the collector, the gate potential increases and current flows through the collector. At this point, if there is a high voltage between the collector and emitter, it may cause the IGBT to heat up and even be damaged. When using IGBT, if the gate circuit is abnormal or damaged (the gate is in an open circuit state), if voltage is applied to the main circuit, the IGBT will be damaged. To prevent such faults, a resistor of about 10K Ω should be connected in series between the gate and emitter.
When installing or replacing IGBT modules, great attention should be paid to the contact surface condition and tightening degree between the IGBT module and the heat sink. To reduce contact thermal resistance, try to apply thermal grease between the heat sink and IGBT module. Generally, there is a cooling fan installed at the bottom of the heat sink. When the cooling fan is damaged and the heat dissipation of the heat sink is poor, it will cause the IGBT module to heat up and malfunction. Therefore, regular inspections should be conducted on the cooling fan. Generally, a temperature sensor is installed near the IGBT module on the heat sink. When the temperature is too high, an alarm will be triggered or the IGBT module will stop working.