Influence of additives and pulse parameters on uniformity of through-hole copper plating

Chen

et al. 2018

Purpose Optimized plating conditions, included proper designs of insulating shield (IS), auxiliary cathode (AC) and different patterns, contribute to the uniformity enhancement of copper deposition. Design/methodology/approach Plating experiments were implemented in vertical continuous plating (VCP) line for manufacturing in different conditions. Multiphysics coupling simulation was brought to investigate and predict the plating uniformity improvement of copper pattern. In addition, the numerical model was based on VCP to approach the practical application. Findings With disproportionate current distribution, different plating pattern design formed diverse copper thickness distribution (CTD). IS and AC improved plating uniformity of copper pattern because of current redistribution. Moreover, optimized plating condition for effectively depositing more uniformed plating copper layer in varied pattern designs were derived by simulation and verified by plating experiment. Originality/value The comparison between experiment and simulation revealed that multiphysics coupling is an efficient, reliable and of course environment-friendly tool to perform research on the uniformity of pattern plating in manufacturing.

Section: Resultsmentioning

confidence: 99%

Improvement of plating uniformity for copper patterns of IC substrate with multi-physics coupling simulation

Chen

et al. 2018

“…With the development of electronics becoming lighter, thinner and smaller, the pursuit for more densely integrated printed circuit board (PCB) is growing drastically (Dunfa et al, 2001;Wang et al, 2012;Wang et al, 2013). Through-holes (THs) with different aspect ratio (AR) are fabricated to meet the various requirements of multi-functional PCB.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation and experiments to improve throwing power for practical PCB through-holes plating

Chen

et al. 2019

Purpose The purpose of this study is to investigate the synergism of convection, current density distribution and additives by numerical simulation and electrochemical experiments for good throwing power (TP) of copper electro-deposition in printed circuit board (PCB) manufacture. Design/methodology/approach The flow field of THs and current density distribution on various AR of THs are calculated and analyzed. Meanwhile, corresponding simulation is used to study the performance of plating electrolytes on TP. Two electrochemical parameters, overpotential (η) and potential difference (△η), are chosen to evaluate the electrochemical properties of different plating solutions by galvanostatic measurement and potentiodynamic cathode polarization at different rotating speeds. Findings By combining both the results of simulation and practical plating, these two electrochemical properties of electrolytes exhibit significant impact to the system at varied conditions. Especially, the electrolyte with higher polarizing η and △η values lead to the elevated TP for AR of more than 2:1. Originality/value The harring cell model is built as a bridge between the theoretical and experimental study for control of uniformity of plating THs in PCB manufacturing. This dual-parameter evaluation is validated to be a promising decisive method to guide the THs plating with particular AR in industry.

“…pulse current) and organic additives in plating electrolyte. [9][10][11][12] Mass transport has been generationally improved by structural evolution of the plating bath, and vertical continuous plating (VCP) line is the most advanced and the fastest growing equipment at present. Pulse current is an accessible way to enhance uniformity of THs electroplating, but it is faced with the problems of copper nodules and matted copper surface.…”

mentioning

confidence: 99%

Electrochemical Factors of Levelers on Plating Uniformity of Through-Holes: Simulation and Experiments

et al. 2018

J. Electrochem. Soc.

In this paper, potentiodynamic cathode polarization, chronopotentiometry and galvanostatic measurement (GM) are applied to obtain electrochemical property of three levelers (oligomers with different ratios of imidazole and 1,4-butanediol diglycidyl ether, named L 1 , L 2 and L 3 , respectively) at different rotation speeds. Measured by GM with varied levelers, potential differences (PDs) are confirmed as effective indicators of THs plating and named η (caused by self-inhibition of leveler) and η r (caused by different convection). The slope of the Tafel curve, obtained by chronopotentiometry, is a bridge to connect PDs to uniformity of THs plating. Also, the multi-physical coupling simulation based on the finite element method is introduced to investigate leveling effect on uniformity. A model based on Haring cell is formulated to predict the relationship between PDs and uniformity. Furthermore, numerical simulation and plating experiment both show that levelers with more negative PDs lead to more uniform conformal THs copper deposition and a systematic relationship between PDs and uniformity of THs plating is established. The weightings of η and η r are also achieved for THs playing. Finally, the model paves an alternative way to screen for better leveler based on the relationship between PDs and uniformity of THs plating.