中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2014年
10期
2565-2575
,共11页
丁康康%肖葵%邹士文%董超芳%李昊然%李晓刚
丁康康%肖葵%鄒士文%董超芳%李昊然%李曉剛
정강강%초규%추사문%동초방%리호연%리효강
覆铜板%无电镀镍金%化学浸银%稀H2SO4
覆銅闆%無電鍍鎳金%化學浸銀%稀H2SO4
복동판%무전도얼금%화학침은%희H2SO4
printed circuit board%electroless nickel immersion gold%immersion silver%dilute H2SO4
采用交流阻抗谱(EIS)和扫描Kelvin探针(SKP)技术研究4种表面工艺处理印制电路板(PCB)试样在不同pH值稀H 2 SO 4液滴下的腐蚀行为,通过体视学显微镜和扫描电镜结合能谱对PCB上液滴扩展和腐蚀行为进行观察分析。结果表明:覆铜板(PCB-Cu)在液滴作用下发生全面腐蚀;无电镀镍金处理电路板(PCB-ENIG)主要为微孔腐蚀,腐蚀微孔数目由液滴边缘向液滴中心区域逐渐递减,而化学浸银处理电路板(PCB-ImAg)的腐蚀仅局限于液滴边缘,两者基底金属均发生了不同程度的腐蚀;热风整平无铅喷锡板(PCB-HASL)的腐蚀最轻微。结合EIS和SKP分析表明:稀H 2 SO 4能够活化液滴作用区域,增大试样表面电位差,从而促进试样腐蚀;整体上,PCB-ENIG试样的耐蚀防护性能略优于PCB-ImAg试样的,PCB-HASL的最优。
採用交流阻抗譜(EIS)和掃描Kelvin探針(SKP)技術研究4種錶麵工藝處理印製電路闆(PCB)試樣在不同pH值稀H 2 SO 4液滴下的腐蝕行為,通過體視學顯微鏡和掃描電鏡結閤能譜對PCB上液滴擴展和腐蝕行為進行觀察分析。結果錶明:覆銅闆(PCB-Cu)在液滴作用下髮生全麵腐蝕;無電鍍鎳金處理電路闆(PCB-ENIG)主要為微孔腐蝕,腐蝕微孔數目由液滴邊緣嚮液滴中心區域逐漸遞減,而化學浸銀處理電路闆(PCB-ImAg)的腐蝕僅跼限于液滴邊緣,兩者基底金屬均髮生瞭不同程度的腐蝕;熱風整平無鉛噴錫闆(PCB-HASL)的腐蝕最輕微。結閤EIS和SKP分析錶明:稀H 2 SO 4能夠活化液滴作用區域,增大試樣錶麵電位差,從而促進試樣腐蝕;整體上,PCB-ENIG試樣的耐蝕防護性能略優于PCB-ImAg試樣的,PCB-HASL的最優。
채용교류조항보(EIS)화소묘Kelvin탐침(SKP)기술연구4충표면공예처리인제전로판(PCB)시양재불동pH치희H 2 SO 4액적하적부식행위,통과체시학현미경화소묘전경결합능보대PCB상액적확전화부식행위진행관찰분석。결과표명:복동판(PCB-Cu)재액적작용하발생전면부식;무전도얼금처리전로판(PCB-ENIG)주요위미공부식,부식미공수목유액적변연향액적중심구역축점체감,이화학침은처리전로판(PCB-ImAg)적부식부국한우액적변연,량자기저금속균발생료불동정도적부식;열풍정평무연분석판(PCB-HASL)적부식최경미。결합EIS화SKP분석표명:희H 2 SO 4능구활화액적작용구역,증대시양표면전위차,종이촉진시양부식;정체상,PCB-ENIG시양적내식방호성능략우우PCB-ImAg시양적,PCB-HASL적최우。
The electrochemical impedance spectroscopy (EIS) and scanning Kelvin probe (SKP) testing techniques were used to study the corrosion behavior of four kinds of printed circuit boards (PCB) under dilute H2SO4 droplets with different pH values. Meanwhile, the corrosion morphology was observed and analyzed. The results show that general corrosion occurs on the printed circuit board PCB (PCB-Cu) surface under the droplet. The corrosion behavior of electroless nickel immersion gold finishing PCB (PCB-ENIG) is mainly in form of microporous corrosion, and the corroded micropores develop from the edge of droplet to the center, while the corrosion regions of immersion silver finishing PCB (PCB-ImAg) are confined at the edge region of droplet, the substrate metals for PCB-ENIG and PCB-ImAg are both corroded to some extent. Among four PCB materials, the hot air solder leveling PCB (PCB-HASL) corrodes the most mildly. EIS and SKP results show that the dilute sulfuric acid droplets can activate the sample surface and form a large potential difference on the whole droplet region, contributing to the further corrosion process. Overall, the corrosion resistance and protection performance of PCB-ENIG is better than that of PCB-ImAg, while PCB-HASL is the best without any corrosion occurring on the substrate.