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随着电子技术的飞速发展,大功率晶体管应用日益广泛,进一步提高大功率晶体管的可靠性,对电子产品质量的提高有很大意义。1 晶体管损坏原因(1)电路中的电压、电流、输出功率过载引起损坏在晶体管电路中主要与集电极—发射极间电压 V_(ce)、集电极—基极间电压V_(cb)与晶体管固有的特性参数(如 BV_(cbo)、BV_(ceo)、I_(cbo)、I_(ceo)、P_(cm))及工作条件(BV_(ceo)、BV_(cex))有关。如果电路中晶体管的集电极 BV_(ceo)电压超过了最大值,就会造成晶体管的损坏。(2)热损坏在晶体管手册中一般所指的最大电压,通常是常温(25℃)下的值。因此,在环境温度较高或在最高结温下使用时,晶体管工作的实际最大电压将小于常温时的值,此时晶体管的 I_(cbo)和 I_(ebo)也会增加,造成结温上升,而结温升高又会使 I_(cbo)和I_(ebo)更进一步增大而形成雪崩现象,结果热击穿而损坏。(3)二次击穿引起的损坏在晶体管电路中,当集电极电压
With the rapid development of electronic technology, the application of high-power transistors is becoming more and more widespread, and the reliability of high-power transistors is further improved, which is of great significance to the improvement of the quality of electronic products. 1 transistor damage causes (1) the circuit voltage, current, output power overload caused by damage in the transistor circuit mainly with collector-emitter voltage V ce, collector-base voltage V cb and the transistor Inherent characteristic parameters (such as BV_ (cbo), BV_ (ceo), I_ (cbo), I_ (ceo), P_ (cm)) and working conditions (BV_ (ceo), BV_ (cex) If the collector of the transistor in the circuit BV ceo voltage exceeds the maximum, it will cause the transistor damage. (2) Thermal damage The maximum voltage normally referred to in the transistor manual, usually at room temperature (25 ° C). Therefore, when the ambient temperature is high or at the maximum junction temperature, the actual maximum voltage of the transistor will be lower than the value at normal temperature. At this time, the I cbo and I ebo of the transistor also increase, causing the junction temperature to rise , And the increase of junction temperature will make I_ (cbo) and I_ (ebo) further increase the formation of avalanche phenomenon, the result of thermal breakdown and damage. (3) Damage caused by secondary breakdown In the transistor circuit, when the collector voltage