Studies of polixetonium chloride as a novel, hypotoxic and single additive of copper electronic plating for microvia void-free filling in printed circuit board application

The void-free filling of microvia through copper electronic plating in printed circuit board application relies critically on multi-component additives including suppressor, accelerator, and leveler. In this study and for the first time, we have developed a new hypotoxic additive, Polixetonium Chloride (PC), as a single component additive in copper electronic plating. Chronocoulometric measurements and finite element method computations combined with Cu electronic plating indicate that the PC can inhibit copper deposition at the mouth of microvia and improve copper deposition at the bottom of microvia by increasing local current densities. Chronopotentiometric studies and in situ FTIR spectroscopic analysis together with density functional theory calculations illustrate that Cl− behaves the anchor of PC to enhance its adsorption, and the adsorption ability of PC in microvia is gradually weakened from top to bottom, which is in favor of the electrodeposition of cupric ions at the bottom of microvia for void-free filling.