AC Impedance and Coulostatic Studies on Electrochemical Detection of 2‐Mercaptobenzothiazole in a Copper Electroless Plating Bath

Abstract

A concentration evaluation method for 2-mercaptobenzothiazole, which is a common additive in copper electroless plating baths, was demonstrated. This method consists of measuring polarization resistance values for a platinum electrode on which no copper deposition occurs at a predetermined immersion time. The reaction proceeding on the platinum electrode in this case was analyzed by the coulostatic method and ac impedance measurements using coulostatic pulse perturbation combined with an FFT spectrum analyzer. It was revealed that formaldehyde oxidation by dissolved oxygen is a predominant reaction, and that 2-MBT inhibits this reaction markedly by adsorption with low coverage, leading to an increase in polarization resistance values.

Impedance and Morphological Properties of Electroless Gold on Industrial Metal Coupons

“…Electrochemical impedance spectroscopy (EIS) was used to generate qualitative information on the substrate surface/solution interactions occurring during the electroless gold process. The utility of EIS in providing mechanistic and kinetic information has been recently demonstrated in the study of zinc oxide layers under various illumination conditions, the oxidation of formaldehyde on gold, and the study of electroless Cu and Ni deposition. − To date, we are not aware of any EIS studies on the electroless gold bath using DMAB as reducing agent. Scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS) were used in assessing bath performance with regards to surface quality and elemental composition on plated wirebond samples.…”

The effect of 2-mercaptobenzothiazole on laser-assisted electroless copper plating

“…13 Among these additives, 2-MBT is especially attractive because while improving coating quality, it accelerates the electroless copper plating process rather than decelerating it. 14,15 To date, the understanding of the plating process with 2-MBT is very limited. Previous works mainly focused on optimizing process while effects of 2-MBT additions on the electroless copper plating process are still remain not fully understood.…”