压接型IGBT内部栅极电压一致性影响因素及调控方法

Influence Factors and Control Method of Gate Voltage Uniformity in Press-Packed IGBTs

压接型绝缘栅双极晶体管(IGBT)的驱动印制电路板(PCB)寄生参数不一致会引起瞬态过程中内部IGBT芯片栅极电压不一致,芯片不能同时开通,造成芯片的瞬态不均流。结合压接型IGBT驱动PCB结构及运行工况,建立了包含驱动源、芯片模型、驱动PCB的一体化电路模型,分析了栅极内电阻、栅射极电容以及驱动电阻对驱动电压一致性的影响。在此基础上提出了驱动PCB电感匹配、并联芯片数匹配以及集中电阻补偿的驱动PCB的调控方法,以实现对栅极电压一致性的有效调控。研究表明驱动电阻是造成芯片栅极电压不一致的主要因素。利用上述调控方法可将芯片开通时间的不均衡度由79.2%分别降低至2.86%、7.1%和7.5%,实验验证了所提出的驱动PCB调控方法的有效性。

The inconsistency of parasitic parameters of drive print circuit board(PCB)for the press-packed insulated gate bipolar transistor(IGBT)will cause the inconsistency of gate voltages of the internal IGBT chip during the transient process, and chips can’t be turned on at the same time, resulting in the transient current unbalance of chips.Combined with the structure and operating conditions of the press-packed IGBT drive PCB,an integrated circuit model including the drive source, chip model and drive PCB was established.The influences of the internal gate resistance, gate-emitter capacitance and drive resistance on the uniformity of the drive voltage were analyzed. On this basis, the control methods of the drive PCB by inductance matching, branch chip number matching and concentrated resistance compensation were proposed to achieve the effective regulation of gate voltage uniformity. The researches show that the drive resistance is the main factor that causes the inconsistency of the gate voltage of the chip.By applying the above control methods, the turn-on time inconsistency of the chip can be reduced from 79.2% to 2.86%,7.1% and 7.5%,respectively. The experiments verify the effectiveness of the proposed control method of the drive PCB.