小型耐热聚丙烯薄膜电容的结构优化研究

Research on Structure Optimization of Small-Sized Heat-Resistance Polypropylene Film Capacitance

小型金属化聚丙烯薄膜电容过265℃波峰焊后出现本体炸裂失效,通过失效原因排查和实验分析,发现薄膜材料和直引脚结构是小型电容无法承受265℃高温而炸裂失效的主要原因。为寻找改进方案以防止此类失效故障再次出现,作者着重对小型电容的材料对比和结构优化进行研究,结果显示,聚丙烯薄膜电容比聚酯薄膜电容的电性能更优越,电容直引脚进行弯折成型,可有效提高其耐热性能;电容包封形式选用壳式灌封,可有效降低外观包封材料炸裂的可能性。在实际的生产试验中,结构优化后的电容能够满足生产和应用需求,有效解决过波峰焊时炸裂失效的问题。

The smaller metalized polypropylene film capacitance may get burst and failed after 265 ℃ wave soldering, through the analysis on failure reasons and experiments, it showed that the thin film material and the straight pin structure were the main reasons which made the small capacitance cannot withstand 265 ℃ high temperatures and led to burst failure. In order to find an improved scheme to prevent this kind of failure from happening again, the material contrast and optimum structure of small capacitance were studied. The results showed that the electric performance of the polypropylene film capacitance was better than that of polyester film. The heat resistance can be improved effectively by bending the straight pin, and the shell-type packing can effectively reduce the possibility of encapsulation material failure. In the actual production test, the improved capacitance with optimum structure could meet the needs of production and application, and it effectively solved the problem of burst failure during wave soldering.