pn结中的小电流过趋热效应及理论模拟计算

Excessive Thermotaxis Effect of Low Current in pn Junction and Theoretical Analog Calculation

晶体管在耗散功率时,结温分布一般不均匀.在晶体管子管并联模型的基础上,经过实验和理论模拟计算及验证发现结温分布不均匀时,高温区的电流密度大于低温区的电流密度;测试电流越小,高温区与低温区电流密度的比值越大,电流越集中在高温区,且集中区域的面积随着测试电流的减小而缩小,这种现象称为小电流过趋热效应.利用这一特性可以研究晶体管结温分布的不均匀性,计算结温分布的不均匀度,对半导体器件可靠性分析具有重要的意义.

When a transistor dissipates power on work,its junction temperature distribution is commonly non-uniform. Based on a sub-transistor shunt connection model, by theoretical analog calculation and experiment,it is found that in a non-uniform junction temperature distribution,the current density of the high-temperature region is higher than that of the low-temperature region. The ratio of the current density of the high-temperature region to that of the low-temperature region increases with the decrease of the measuring current. This phenomenon is called the excessive thermotaxis effect of low current. Based on these characteristics, the uniformity of the junction temperature distribution is studied.