EMI滤波器和DC/DC电源模块失效案例分析

The Failure Analysis of EMI Filter and DC/DC Converter Module

混合集成EMI滤波器和DC/DC电源模块广泛地应用于军工领域。由于电源需要连续运行,同时经受恶劣环境条件考验,EMI滤波器和电源模块失效情况时有发生。针对某装备中滤波模块和电源模块的失效案例开展分析,详细地介绍了该类混合电路失效分析方法,提出了混合电路失效分析的思路,找到了滤波模块和电源模块的失效原因和机理,并给出了相应的改进措施,为电源模块的失效分析开展提供了参考。经失效分析,发现滤波模块和电源模块的失效原因为电源模块内部电阻受损,使用过程中微裂纹扩展,电阻开路,导致与之相连的MOSFET过功率烧毁,电源模块输入和输入地短路失效。电源模块短路失效,导致滤波模块的输出与输出地短路,从而形成大电流,导致基板过温,部分元器件焊点脱落,最终导致滤波模块无输出。

The EMI filter and DC/DC converter module in hybrid integrated process are widely used in military field.Since the power supply needs continuous operation and withstands the test of harsh environment conditions,the failure of EMI filter and DC/DC converter module happen on occasion.The failure cases of filter and converter module in an equipment are analyzed,the hybrid integrated circuit failure analysis methods are introduced in detail,the idea of the hybrid integrated circuit failure analysis is put forward,the failure causes and mechanisms of filter and converter module are found,and the corresponding improvement measures are proposed,which provides a reference for the failure analysis of converter module.After failure analysis,it is found that the reason for the failure of the filter and converter module is the damage to the internal resistance of the power module,and microcraks propagates and the resistance opens during use,which causes the MOSFET connected to it to burn out due to excessive power and the input and input ground of the power moduce are short circuited.The short-circuit power module leads to the short out between the output of the filtering module and the output ground,which results in a large current,and causes the substrate to overheat and some component solder joints fall off.As a result,the filter module has no output.