Thermal resistance matrix representation of thermal effects and thermal design in multi-finger power heterojunction bipolar transistors

• Published in: Chinese physics B 2011-06, Vol.20 (6), p.277-282
• Main Author: 金冬月 张万荣 陈亮 付强 肖盈 王任卿 赵昕
• Format: Article
• Language: English
• Subjects: 异质结双极晶体管; 手指; 热效应; 热敏电阻; 热电阻; 热设计; 矩阵表示; 高功率器件
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/20/6/064401

The thermal resistance matrix including self-heating thermal resistance and thermal coupling resistance is presented to describe the thermal effects of multi-finger power heterojunction bipolar transistors. The dependence of thermal resistance matrix on finger spacing is also investigated. It is shown that both self-heating thermal resistance and thermal coupling resistance are lowered by increasing the finger spacing, in which the downward dissipated heat path is widened and the heat flow from adjacent fingers is effectively suppressed. The decrease of self-heating thermal resistance and thermal coupling resistance is helpful for improving the thermal stability of power devices. Furthermore, with the aid of the thermal resistance matrix a 10-finger power heterojunction bipolar transistor （HBT） with non-uniform finger spacing is designed for high thermal stability. The optimized structure can effectively lower the peak temperature while maintaining a uniformity of the temperature profile at various biases and thus the device effectively may operate at a higher power level.