Investigation of poly (2-methyl imidazole co 1,4-butanediol diglycidyl ether) as a leveler for blind hole copper plating

Abstract

<p>The current synthetic leveler agents are complex to operate, troublesome to purify, and low to pore filling rates. Herein, we report a new, simple, green, and inexpensive method for the synthesis of leveler agents and study their properties systematically. In acidic copper sulfate plating solutions, including polyethylene glycol (PEG), sodium 3,3’-dithiodipropane sulfonate (SPS), and chloride ions, the relation between leveler agents (dimethylimidazole and 1,4-butanediol diglycidyl ether) and the filling of blind holes have been investigated. The synthesized leveler agent was structurally characterized by infrared spectroscopy and gel chromatography tests. The plating containing the leveler agent passed plating tests as well as reliability tests and met PCB production requirements. The electrochemical behavior of the leveler agent was investigated using electrochemical tests. The X-ray diffractometer (XRD) was used to observe the differences in crystal orientation on the surface of the plated layers.<strong></strong></p>