热处理对钽芯及钽电容器电性能的影响

The effect of heat treatment on electrical properties of tantalum cores and capacitors

在实际使用过程中,钽电容器常因电容量、损耗和漏电流发生漂移而失效。为了改善钽电容器的电性能稳定性,系统研究了在空气环境中热处理对形成后的钽芯及钽电容器电性能的影响。采用阳极氧化法在烧结后的钽块表面形成Ta_(2)O_(5)介质氧化膜,然后对阳极钽芯进行热处理。研究结果表明:热处理对钽芯的击穿电压和漏电流传导机理无明显影响;热处理后的钽芯表面Ta_(2)O_(5)介质氧化膜的微观形貌未发生明显变化;经过适当热处理且补形成后的阳极钽芯的漏电流及所制备的钽电容器电容量稳定性、损耗和漏电流均得到了明显改善;合适的热处理工艺为300℃/45~60 min。

In practical application,failure of tantalum capacitors is often due to the drift of capacitance,dissipation factor and leakage current.Here the effects of heat treatment on electrical performance of prepared tantalum cores and capacitors in air were systematically determined to improve the electrical stability of tantalum capacitors.Ta_(2)O_(5) dielectric oxide films was formed on the surfaces of sintered tantalum blocks by anodic oxidation process,and then heat treatment of the anodic tantalum cores was performed.Results show that heat treatment has no obvious effect on breakdown voltage and leakage current conduction mechanism of the tantalum cores.The microstructure of the Ta_(2)O_(5) dielectric oxide film on the annealed tantalum cores has no discernible change.After proper heat treatment,the leakage current of the tantalum cores,the stability and dissipation factor of the tantalum capacitors can be significantly improved.The appropriate heat treatment should be performed at 300℃for 45-60 min.