关键词: 表面处理工艺, 化学镍钯浸金工艺, 有机基板, 镍腐蚀

Abstract: Organic substrates are widely used in the field of electronic packaging, and common surface treatment processes include electroplating nickel-gold, chemical nickel-gold, immersion tin, immersion silver and other processes. Among the various surface treatment processes, the chemical nickel-palladium immersion gold process shows significant advantages due to its good comprehensive performance. Chemical nickel-palladium immersion gold process is based on the chemical nickel-gold process with the addition of chemical palladium plating process. This process first performs chemical nickel plating treatment on the substrate surface, followed by chemical palladium plating treatment, and finally completes the chemical immersion gold treatment. The palladium coating can prevent the gold from corroding the nickel layer during deposition process and prevent nickel from diffusing into the intermetallic compound (IMC) layer. By using X-Ray, scanning electron microscopy (SEM), focused ion beam (FIB) and other image analysis methods, the thickness, micro-morphology and quality of chemical nickel-palladium immersion gold coatings from different manufacturers are compared, and the results show that the flat and dense palladium coating can effectively avoid the nickel corrosion phenomenon.

Key words: surface treatment process, chemical nickel-palladium immersion gold process, organic substrate, nickel corrosion