Chem. J. Chinese Universities ›› 2024, Vol. 45 ›› Issue (8): 20240146.doi: 10.7503/cjcu20240146

• Physical Chemistry • Previous Articles     Next Articles

Influence Mechanism of Synergistic Additives on the Nucleation and Coating Morphology and Structure of Copper Electronic Plating

JIN Lei1(), WANG Zhaoyun2, YANG Fangzu3, ZHAN Dongping3   

  1. 1.Chongqing Key Laboratory of Extraordinary Bond Engineering and Advance Materials Technology(EBEAM),School of Materials Science and Engineering,Yangtze Normal University,Chongqing 408100,China
    2.School of Electronic Science and Engineering
    3.State Key Laboratory of Physical Chemistry of Solid Surfaces,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China
  • Received:2024-03-27 Online:2024-08-10 Published:2024-07-03
  • Contact: JIN Lei E-mail:leijin@yznu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(22132003);the Research Funding Project of Yangtze Normal University, China(010730153)

Abstract:

In this work, based on the acidic copper sulfate electronic plating formula and process for through-hole uniform thickening of printed circuit board(PCB) with 1-(2-pyridylazo)-2-naphthol(PAN) as a synergistic additive, the influence mechanism of the additives on the copper electro-crystallization process was clarified by using the electrochemical chronoamperometry. Polyethylene glycol(PEG) destroys the copper nucleation process, bis-(3-sulfopropyl)disulfide(SPS) and PAN do not affect the occurrence of copper nucleation behavior, and the synergic effects of PEG, SPS and PAN can further promote the formation of copper nuclei. Both PEG and SPS promote the adsorption of PAN on the copper surface confirmed through electrochemical in situ Raman spectroscopy. The effects of additives on the morphology of copper coating are analyzed by scanning electron microscopy. Only SPS can refine the copper coating particles, and the synergistic effects of PEG, SPS and PAN is beneficial to obtain copper coating with finer and more uniform particles. The crystal face orientation of copper coating and the crystal face sites adsorbed by additives are revealed by X-ray diffraction. Both PEG and PAN are easy to adsorb on the (111) crystal face and inhibit the (220) crystal face. SPS is easy to adsorb on the (220) crystal face and promotes the (220) crystal face to be preferred. The combined action of PEG and SPS can make copper grow along the (111), (200) and (220) crystal faces, and (200) is a relatively preferred crystal face. The complex synergistic effects among the three additives promote the preferential growth of copper along the (111) and (200) crystal faces.

Key words: Copper electronic plating, Additives, Nucleation, Morphology, Preferential orientation, Synergistic effect

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