光伏逆变器用大功率开关晶体管结构参数的设计

摘要

集电极峰值电流(ICM)、集电极-发射极击穿电压(VCEO)、最大耗散功率(PCM)、直流二次击穿临界电压(VSB)是衡量大功率晶体管可靠性优劣的重要指标.根据光伏逆变器实际参数指标的要求,对光伏逆变器中的核心功率开关器件的结构参数进行优化.根据大电流特点,重点对大功率开关晶体管高阻单晶硅电阻率、高阻集电区厚度、发射区版图及用于改善二次击穿的浮空发射区结构参数进行分析和设计.最终完成800V/15A大功率开关晶体管全套结构参数的设计,并提供了可供大功率晶体管设计使用的曲线和图表.设计结果表明:对大功率开关晶体管进行结构设计时,需着重考虑大功率开关晶体管在大电流、高反压、高频等工作状态下,极易出现的发射极电流过度集中导致器件损坏的现象.%Peak collector current (ICM), collector to emitter breakdown voltage (VCEO), collector maximum power dissipation (PCM), and DC secondary breakdown threshold voltage (VSB) are important indexes of measuring high power transistor reliability. According to the requirement of the photovoltaic inverter actual parameters, the structure parameters of the core power switch devices in photovoltaic inverters is optimized. According to the characteristics of the large current, the analysis and design of high power switch transistorin is focusing on the high resistance monocrystal silicon resistivity, high resistance collector area thickness, emitter area layout and floating emitter area used to improve the secondary breakdown. Finally,the design of full structure parameters of 800V/15A power switch transistor is completed, and the curves and graphs are supplied to high power switch transistor design for use. The design results show that the structure designing of high power switch transistor needs to focus on the phenomenon that devices are liable to be damaged by excessive emitter current concentration under the working conditions such as large current, high reverse bias voltage and high frequency.