SIC High-Performance Welding Systems


"Silicon Carbide"- Pipe Welder

The SIC High-efficiency switch welder is designed for straight seam induction welding of steel tubes. It mainly uses UJ3C120040K3S (SIC) and DSEI60-06A (fast recovery diode), rectifier diodes, and modular Power component consisting of high-power IGBT and other power devices. The high-power capacitor bank C and the inductance coil L form the current-mode parallel boost resonant circuit. This kind of circuit adapts to the high-frequency welded pipe with low load impedance and does not require the output transformer. This not only improves the efficiency but also increases the reliability of the whole machine.

The high-efficiency switch welder owns the following obvious features of significant energy conservation, good welding quality, small size, easy maintenance, low failure rate, and low maintenance cost, etc.

Comparison between HF Welder with MOSFET vs SIC
Type-Nr. On-resistance Drain-Source-
Voltage (V)
Conti. Drain Current (A)
(@ 25℃)
Turn-On Delay Time Rise Time Turn-Off Delay Time Fall Time

Benefits of SIC-JFET (Silicon Carbide Junction Field-Effect Transistor)

Low line loss

At similar power levels, SIC conduction loss is much lower than MOSFET, almost one-eighth of MOSFET conduction loss. Unlike MOSFET, the conduction loss of SIC hardly changes with temperature

High voltage rating

The breakdown field strength of SIC is more than ten times that of Si, so the blocking voltage of SiC is much higher than that of MOSFET. The rated voltage of the mosfet is 500V, but the rated voltage of the SIC can reach 1200V.

Higher working temperature

SIC has an extremely stable crystal structure in terms of physical properties, and its bandwidth can reach 2.2EV to 3.3EV. The SIC therefore ensures that the welding machines run stably.

Large continuous current

At the same working temperature, the SIC continuous current is more than three times that of the MOSFET. For example, at 25°C, the current of the mosfet is 20A, the current of the SiC can reach up to 62A.

Fast switching speed, low switching loss

The thermal conductivity of SiC is almost 2.5 times that of Si material, and the saturation electron drift rate is twice that of Si material, so the SiC device can operate at a higher frequency. Benefit from the fast switching speed, the switching loss is significantly lower

The high voltage and current of SIC provides a more reliable guarantee for stable operation of welding machine. Moreover, the SIC is more durable, reduced the down-time rate. Compared with MOSFET high-frequency welding machine, the withstand voltage and current overtload margin of SIC high-frequency welding machine are significantly improved (10% higher than that of other manufacturers in the same industry). Compared with MOSFET, the temperature range of SIC is wider; therefore, SIC works more stably and has longer service life under the same working condition.