工程科学学报，第37卷，第12期：1601-1609,2015年12月 Chinese Journal of Engineering,Vol.37,No.12:1601-1609,December 2015 D0l:10.13374/j.issn2095-9389.2015.12.011:http://journals..ustb.edu.cn 盐雾对喷锡和化金印制电路板腐蚀行为的影响 易盼，丁康康，宋维锋，董超芳，李晓刚，吴俊升，肖葵⑧ 北京科技大学腐蚀与防护中心，北京100083 ☒通信作者，Email:xiaokui(@sina.com 摘要采用交流阻抗谱研究热风整平无铅喷锡处理印制电路板(PCB-HASL)和无电镀镍金电路板(PCB-ENIG)在盐雾环 境下的电化学腐蚀行为，并结合体式学显微镜、扫描电镜、X射线能谱等手段分析两种不同表面处理工艺电路板的腐蚀产物 形貌，组成和镀层失效机制.结果表明：盐雾环境下，PCB-HASL和PCB-ENIG均发生严重腐蚀：镀S层开始发生局部腐蚀， 随后几乎整个表面都发生腐蚀，出现类似均匀腐蚀的现象，镀金板主要发生微孔腐蚀.在PCB-HASL腐蚀过程中，CI~的侵蚀 作用促进S层的腐蚀，后来由于逐渐形成大量的覆盖在镀层表面的腐蚀产物，使得腐蚀速率降低：而在PCB-ENIG腐蚀过程 中，微孔处形成含CIˉ电解质薄液层，Ni与Aū构成腐蚀电偶，从而加速Ni的腐蚀，最终使Cu基底裸露，造成电路板失效. 关键词印制电路板：盐雾实验：腐蚀：失效 分类号TG174.4 Effect of salt spray environment on the corrosion behavior of PCB-HASL and PCB-ENIG YI Pan,DING Kang-kang,SONG Wei-feng,DONG Chao-fang,LI Xiao-gang,WU Jun-sheng,XIAO Kui Corrosion and Protection Center,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:xiaokui@sina.com ABSTRACT The corrosion behavior of hot air solder level printed circuit boards (PCB-HASL)and electroless nickel immersion gold printed circuit boards (PCB-ENIG)in salt spray test was studied by electrochemical impedance spectroscopy.The corrosion product morphology,composition and coating failure mechanism were observed by stereo microscopy,scanning electron microscopy and energy-dispersive X-ray spectroscopy.The results show that PCB-HASL and PCB-ENIG suffer severe corrosion in high salt spray en- vironment.Localized corrosion occurs first in the Sn plating layer,and then almost entire surface corrosion occurs,similar to uniform corrosion.PCB-ENIG mainly generates microporous corrosion.In the PCB-HASL corrosion process,Cl"promotes the corrosion of the Sn layer,then a large amount of corrosion product gradually forms and covers the Sn surface,it makes the corrosion rate reduce. In the PCB-ENIG corrosion process,a thin liquid layer containing Clelectrolyte forms in micropores,and galvanic coupling between gold and nickel constitutes,which accelerates Ni corrosion.The Cu base directly exposes in the adverse environment after Ni suffers serious corrosion,finally leading to electronic component failure. KEY WORDS printed circuit boards:salt spray test:corrosion:failure 电子装置发展的趋势是更小、更轻，从而使更多的 制电路板(PCB)上的铜不被氧化并且具有良好的可焊 组件紧密的组装在印制电路板上，但是这将增加电子 性，对其进行表面涂覆处理四.锡和锡合金能够提供 装置腐蚀失效倾向0.通常，为了保护电子装置中印 良好的可焊性和较高的耐蚀性能，而Au/Ni具有优良 收稿日期：2014-08-15 基金项目：国家自然科学基金资助项目(51271032)工程科学学报，第 37 卷，第 12 期: 1601--1609，2015 年 12 月 Chinese Journal of Engineering，Vol． 37，No． 12: 1601--1609，December 2015 DOI: 10． 13374 /j． issn2095--9389． 2015． 12． 011; http: / /journals． ustb． edu． cn 盐雾对喷锡和化金印制电路板腐蚀行为的影响 易 盼，丁康康，宋维锋，董超芳，李晓刚，吴俊升，肖 葵 北京科技大学腐蚀与防护中心，北京 100083  通信作者，E-mail: xiaokui@ sina． com 摘 要 采用交流阻抗谱研究热风整平无铅喷锡处理印制电路板( PCB--HASL) 和无电镀镍金电路板( PCB--ENIG) 在盐雾环 境下的电化学腐蚀行为，并结合体式学显微镜、扫描电镜、X 射线能谱等手段分析两种不同表面处理工艺电路板的腐蚀产物 形貌、组成和镀层失效机制． 结果表明: 盐雾环境下，PCB--HASL 和 PCB--ENIG 均发生严重腐蚀; 镀 Sn 层开始发生局部腐蚀， 随后几乎整个表面都发生腐蚀，出现类似均匀腐蚀的现象，镀金板主要发生微孔腐蚀． 在 PCB--HASL 腐蚀过程中，Cl － 的侵蚀 作用促进 Sn 层的腐蚀，后来由于逐渐形成大量的覆盖在镀层表面的腐蚀产物，使得腐蚀速率降低; 而在 PCB--ENIG 腐蚀过程 中，微孔处形成含 Cl － 电解质薄液层，Ni 与 Au 构成腐蚀电偶，从而加速 Ni 的腐蚀，最终使 Cu 基底裸露，造成电路板失效． 关键词 印制电路板; 盐雾实验; 腐蚀; 失效 分类号 TG174. 4 Effect of salt spray environment on the corrosion behavior of PCB--HASL and PCB--ENIG YI Pan，DING Kang-kang，SONG Wei-feng，DONG Chao-fang，LI Xiao-gang，WU Jun-sheng，XIAO Kui Corrosion and Protection Center，University of Science and Technology Beijing，Beijing 100083，China  Corresponding author，E-mail: xiaokui@ sina． com ABSTＲACT The corrosion behavior of hot air solder level printed circuit boards ( PCB--HASL) and electroless nickel immersion gold printed circuit boards ( PCB--ENIG) in salt spray test was studied by electrochemical impedance spectroscopy． The corrosion product morphology，composition and coating failure mechanism were observed by stereo microscopy，scanning electron microscopy and energy-dispersive X-ray spectroscopy． The results show that PCB--HASL and PCB--ENIG suffer severe corrosion in high salt spray en￾vironment． Localized corrosion occurs first in the Sn plating layer，and then almost entire surface corrosion occurs，similar to uniform corrosion． PCB--ENIG mainly generates microporous corrosion． In the PCB--HASL corrosion process，Cl － promotes the corrosion of the Sn layer，then a large amount of corrosion product gradually forms and covers the Sn surface，it makes the corrosion rate reduce． In the PCB--ENIG corrosion process，a thin liquid layer containing Cl － electrolyte forms in micropores，and galvanic coupling between gold and nickel constitutes，which accelerates Ni corrosion． The Cu base directly exposes in the adverse environment after Ni suffers serious corrosion，finally leading to electronic component failure． KEY WOＲDS printed circuit boards; salt spray test; corrosion; failure 收稿日期: 2014--08--15 基金项目: 国家自然科学基金资助项目( 51271032) 电子装置发展的趋势是更小、更轻，从而使更多的 组件紧密的组装在印制电路板上，但是这将增加电子 装置腐蚀失效倾向［1］． 通常，为了保护电子装置中印 制电路板( PCB) 上的铜不被氧化并且具有良好的可焊 性，对其进行表面涂覆处理［2］． 锡和锡合金能够提供 良好的可焊性和较高的耐蚀性能，而 Au /Ni 具有优良