what is etching
Once the PC boards have the artwork applied, the boards are immersed in a warm solution of ferric chloride which should cover the board by about 1/4”. The etchant is easily available at local stores or via mail order. The etching should be done in a plastic or glass container; ferric chloride etches metals very rapidly! Be sure to have good ventilation. The boards can take anywhere from 15 to 45 minutes to develop depending on the temperature of the bath, the agitation, and how fresh the solution is. Once all the exposed copper has been etched away, wash the board thoroughly under running water. This will stop the reaction from possibly etching away your traces. Don’t worry if some of the traces were accidentally removed – this is easily fixed. The next step is to drill the board. This should be done using either a drill press or a high-speed drill with size 63-69 drill bits. Do not remove the protective layer on the copper traces; remove this only when you are ready to solder components. This will help prevent oxidation.