奈米鈀金屬活化液之製備及其在化學鍍銅製程之應用

The Study of Pd Nanoparticles and Its Application to Electroless Copper Deposition

彭超(Peng Chao)

指導教授 ： 王詠雲 ； 萬其超

國立清華大學/工學院/化學工程學系/碩士(2006年)

https://doi.org/10.6843/NTHU.2006.00019

摘要

本論文主要探討奈米鈀粒子的製備及其在印刷電路板中作為無電鍍銅活化液的應用，奈米鈀粒子由PVP保護，本研究所選用的分散劑有水相及乙二醇相，目前兩種分散劑中合成出的奈米鈀粒子經過穿透式電子顯微鏡鑑定，都介於2至7奈米之間，且對於無電鍍銅的催化都達到一定的效果。
乙二醇系統的優點在於合成時不用外加還原劑，而是利用以二醇本身在鹼性環境之下能夠脫水形成具有還原力的乙醛，藉以還原鈀的前趨鹽使其成為奈米粒子，但是前趨鹽對乙二醇溶解度不好，合成時間不易控制，本研究首先針對其製備過程作改良，但是發現其所轉化出來的乙醛濃度不能固定，這時原本已經成熟的水相奈米鈀系統便納入考量，水相系統具有製備方便、較高的催化活性。
本研究的另一項重點就是克服奈米鈀系統經過微蝕之後背光不良的問題，我們試著由不同的微蝕配方找出影響背光的原因，並同時從如何提高活化液本身催化能力著手，最後發現在活化液中加入磷酸並控制酸鹼值在2.2可以克服此問題，由極譜儀的測量結果可以發現，乙二醇系統中的奈米鈀粒子很容易被酸所氧化，相對水相系統的奈米鈀粒子對酸具有較好的穩定度。
由奈米鈀所催化的銅層，藉由X光粉末繞射儀以及掃描式電子顯微鏡的觀察，發現其和工業上錫鈀膠體所催化的銅層性質相似，如果能夠提升催化活性，對於取代錫鈀膠體將更有成效。
本研究也針對其吸附機制作探討，藉由X光電子能譜儀找出PVP所包覆的奈米鈀粒子吸附在基板上的原因，相信對於未來增加鈀吸附量和提升催化活性有幫助。

關鍵字

奈米粒子 ； 鈀 ； 無電鍍銅

並列摘要

Pd nanoparticles stabilized by poly(vinylpyrrolidone) (PVP) have been synthesized in ethylene glycol (Pd/PVP/EG) and in water (Pd/PVP). The PVP-stabilized Pd nanoparticles (Pd-based activators) were found to hold strong potential to replace conventional activator Pd/Sn colloid for electroless copper deposition.
However, Pd-based activators led to poor back-light performance with SPS process. Adding phosphoric acid to adjust pH of the activator would improve back-light performance with SPS process for both Pd/PVP and Pd/PVP/EG. We measured the copper deposition rate and palladium adsorption amount by inductively coupled plasma (ICP-MS). The back-light performance of FR-4 substrates with through holes was measured with optical microscope (OM). Zeta potential and X-ray photoelectron spectroscopy (XPS) results confirmed the adsorptive mechanism of Pd-based activators. We found that Pd/PVP added with acid was more easily prepared than Pd/PVP/EG. Furthermore, Pd/PVP added with acid led to higher specific activity and stability than Pd/PVP/EG even though both of them led to qualified back-light performance and similar copper deposition rate. The Pd consumption of Pd/PVP/EG was much more than that of Pd/PVP. We considered that Pd/PVP was more likely to be a candidate than Pd/PVP/EG to compete with Pd/Sn colloid. We also found aeration caused serious oxidation of Pd for acid added Pd/PVP.

並列關鍵字

nanoparticle ； palladium ； electroless copper deposition

參考文獻

5. C. L. Lee, Y. Y. Wang and C. C. Wan, J. Electrochem.Soc., 150, C125 (2003).

17. Takagi et al., U. S. Patent No. 6,156,385 (2000).

18. G. Schmid and L. F. Chi, Adv. Mater., 10, 515 (1998).

20. D. E. Cliffel, F. P. Zamborini, S. M. Gross and R. W. Murray, Langmuir, 16, 9699 (2000).

29. T. Teranishi and M. Miyake, Chem. Mater., 10, 594 (1998).