Research On Additives Used For Copper Electroplating On Printed Circuit Board

Abstract:The research purpose of this thesis is to study several new and excellent additives used in acid electroplating copper of printed circuit board.Five kinds of polymer such as Poly(N-vinyl-N’-propanesulfonic imidazoliniumchloride)(QVIS), Poly(N-vinyl-N’-propanesulfonicimidaz oliniumchloride-co-butylacrylate)(QVIS-BA), Poly(N-vinyl-N’-propane sulfonicimidazoliniumchloride-co-vinylketopyrrolidine)(QVIS-NVP), N-vinylimidazole with polyether chain(VI-BDE) and N-vinylimidazole with sulfonated polyether chain(VIS-BDE) were synthesized with N-vinylimidazole,1,3-propylsultone, butylacrylate, N-vinylketopyrrolidine and1,4-butanediol diglycidyl as raw materials. The solubility of products were tested in dilute sulphuric acid. The structure of products were characterized by IR spectroscopy,1H-NMR spectroscopy and UV, and so on.The products were added in various electroplating additive systems as leveling agent, combined with SH110(as brighter) and PEG8000(as carrying agent). The dosage range and the best dosage level of leveling agent were confirmed by the Hull cell electroplating experiment. Through the Hull cell electroplating experiment and the microstructure of cathode slice, it showed that as long as the products were added into acidic copper plating bath, the rang of brighter area will expand and the smoothness of the surface will improve. The QVIS-BA additive system was the best one by comparison.The electrochemical performance and plating performance of plating bath that containing the above additives were studied. The results showed that this additive systems can promote the polarization greatly, hinder the copper deposition, and improve the throwing and covering power of plating bath. In addition, the promotion effect of the QVIS-BA additive system was the most obvious. Therefore, the QVIS-BA additive system was the best additive system among the system above by comparison.In order to form a better additive system, PN was added into QVIS-BA additive system. A four component three levels orthogonal experiment was designed, we can get that the optimal contents of additives in acidic copper bath constitutes were as follows:QVIS-BA1.8mg/L, PEG8000150mg/L, SH1105mg/L,PN4mg/L. By comparing the QVIS-BA additive system optimized with the ZL630additive system on the market, it showed that the electrochemical performance and plating performance of QVIS-BA additive system was better. All these results can vefify that QVIS-BA additive system was a good additive system.