Electrical Properties of Silicone Gel for WBG-Based Power Module Packaging at High Temperatures
Electrical Properties of Silicone Gel for WBG-Based Power Module Packaging at High Temperatures
复制标题
用于基于WBG的功率模块封装的硅凝胶在高温下的电性能
DOI：
10.1109/tdei.2022.3228759
复制
发表时间：
2023
影响因子：
3.1
通讯作者：
M. Ghassemi
中科院分区：
文献类型：
--
作者：
Boya Zhang;Ziyue Yang;Kaixuan Li;Xinyu Jiang;Xingwen Li;Guiqin Chang;M. Ghassemi
高功率密度设计和新兴的宽禁带(WBG)半导体的趋势将导致电力电子模块的严重温升。在这方面，用于功率模块封装的硅胶在高温和频率下的绝缘性能恶化，这是一个令人担忧的问题，也没有得到很好的研究。本文主要研究了硅凝胶的高温电学性能，包括介电性能、体电阻率和击穿强度。介电响应过程用Cole-Cole模型描述。特别是计算了在脉宽调制(PWM)电压下的介质损耗密度，观察到了介质损耗引起的封装结构温升。发现200℃下的高频介电常数比室温降低了24%，当温度升高到180℃时，体电阻率下降了三个数量级，硅凝胶的50 Hz交流和10 kHz单极方波击穿强度分别比室温降低了50%和42%。当温度升高到200°C时，在PWM电压下的介质损耗增加了四个数量级，但不会导致封装结构的显著温升。
Trends toward high power density designs and emerging wide bandgap (WBG)-based semiconductors will lead to a severe temperature rise in power electronic modules. In this regard, the insulation performance of silicone gel used for power module packaging deteriorates at high temperatures and frequencies, which is a concern and has not been well studied. This study focuses on the electrical properties of silicone gel at high temperatures, including its dielectric properties, volume resistivity, and breakdown strength. A Cole–Cole model was used to describe the dielectric response process. In particular, the dielectric loss density under pulse width modulation (PWM) voltage was calculated, and the temperature rise of the encapsulation structure caused by the dielectric loss was observed. It was found that the high-frequency dielectric constant at 200 °C decreases by 24% compared to room temperature; when the temperature is raised to 180 °C, the volume resistivity drops by three orders of magnitude, and the 50-Hz ac and 10-kHz unipolar square wave breakdown strength of silicone gel is reduced by 50% and 42% compared with those at room temperature. The dielectric loss under PWM voltage increases by four orders of magnitude as the temperature increases up to 200 °C but does not lead to a significant temperature rise in the encapsulation structure.