采用扫描Kelvin探针测试技术研究喷锡处理(Hot air solder level,HASL)印制电路板(Printed circuit board,PCB)在霉菌环境下的腐蚀行为;采用通过体视学显微镜、扫描电镜和能谱分析对印制电路板的霉菌生长和腐蚀情况进行观察和分析。扫描电镜和能谱结果表明,在湿热环境下,绳状青霉在喷锡处理PCB表面具有优先生长特性,表现为簇状菌丝体交织覆盖。PCB表面腐蚀产物脱落,出现漏铜现象。扫描Kelvin探针结果分析表明,喷锡处理PCB表面霉菌菌落区域作为腐蚀电池的阴极受到保护,而菌落边缘区域作为阳极发生腐蚀;扫描Kelvin探针测试技术可以用来表征霉菌环境下的印制电路板腐蚀行为,表征微区电极反应类型和腐蚀进程。
The corrosion behavior of hot air solder level (HASL) finished printed circuit board (PCB) in the mold environment was studied by scanning Kelvin probe (SKP) technology. The mold growth behavior was observed by stereo microscope and SEM, and the corrosion product was analyzed by EDS. The results of SEM and EDS show that Penicilliumfuniculosum has a priority growth characteristics and tufted mycelium coverage on the surface of PCB-HASL specimens under hydrothermal condition, and corrosion product strips off and basal copper leakage appears. SKP results show that the corrosion process of fungal colony area is inhibited as the cathode of corrosion cell, and is accelerated as the anode at the edge of the area. SKP technology can be used to characterize the corrosion behavior of PCB in the mold environment and monitor the micro-type of electrode reaction and corrosion process.