在電子元件應用中腐蝕在可靠度方面為受關注之議題，本研究將比較電鍍鎳鈀金與無電鍍鎳鈀金表面處理之抗腐蝕性，透過單層金屬腐蝕實驗分析各材料之耐蝕性，另藉由複合金屬鍍層之腐蝕結果分析其可靠度與其腐蝕機制，將不同金屬表面處理放置於腐蝕反應腔體中，其腐蝕條件分別為15 ppm、150 ppm以及1500 ppm之二氧化硫氣體，其腐蝕環境溫度為80 °C、濕度為100% RH (relative humidity)，腐蝕時間分別為48、120以及240小時，以了解短時間至長時間之腐蝕結果以及腐蝕性氣體濃度對於腐蝕結果的影響，實驗後藉由掃描式電子顯微鏡(Scanning Electronic Microscopy，SEM)觀察試片表面形貌，能量散射光譜儀(Energy Dispersive X-ray Spectrometer，EDS)分析腐蝕物之元素，以及低掠角X光繞射儀(Grazing Incidence X-ray Diffraction，GIXRD)鑑定其化合物種類，化學分析電子能譜儀(Electron Spectroscopy of Chemical Analysis，ESCA)縱深分析觀察原子於材料間之擴散行為，本研究於腐蝕後之橫截面發現無電鍍鎳鈀金經高濃度腐蝕後在鎳層有掏空現象發生，最後透過上述腐蝕實驗之結果，得知電鍍鎳鈀金表面處理之抗腐蝕能力優於無電鍍鎳鈀金表面處理，藉由分析電鍍與無電鍍複合金屬之結構差異建立鎳鈀金複合金屬層之腐蝕機制。;Corrosion is a serious reliability concern for electronic products. In this study, corrosion resistance of electroplating Ni/Pd/Au is compared with electroless Ni/Pd/Au (ENEPIG) surface finishes, and both of them are plated on Cu pad in automobile printed circuit board (PCB). The corrosion properties of materials were obtained by single coating layer. The samples coated with different surface finishing layers were placed in a chamber of 100% RH (relative humidity) and an ambient of 15 ppm, 150 ppm and 1500 ppm of SO2. After the corrosion test, the morphology of corrosion products formed on the surface were observed by scanning electron microscopy (SEM), and the elements of corrosion products were analyzed by energy dispersive X-ray spectroscopy (EDS). Grazing incident X-ray diffraction (GIXRD) was applied to characterize the crystal structure of the corrosion products. The electron spectroscopy of chemical analysis (ESCA) was used to observe the diffusion of atoms. There were pores in the Ni layer of ENEPIG after corrosion test by observing its cross-section. The results reveal that the electroplating Ni/Pd/Au has better corrosion resistance than the ENEPIG. A mechanism is proposed to discuss the corrosion behaviors for the surface finishes.
