Copper etching in air regenerated cupric chloride solution

Abstract EN

One of the most important steps in the world of printed circuit board manufacturing (PCB) is the copper etching process.

Because of its low cost, environment aspects, and simple regeneration techniques, cupric chloride was chosen to be the most attractive etchant.

Etching of copper from standard single-sided copper boards used usually for printed circuit board fabrication was conducted in a cell containing cupric chloride solution.

Average etching rates were recorded as a function of time, etchant specific gravity, free acid concentration, and temperature.

Air was injected continuously in the etching cell during the process enabling mixing and solution regeneration.

It is found that best operating conditions to obtain maximum etching rate is at 45-55˚C, specific gravity of 1.3-1.4, and free acid concentration of 1.3-1.4 M.