Working instruction for manufacture of printed circuit boards
1.) The copper side of the supporting board must be clean and fat free. Therefore, the copper side has to be cleaned with a household cleaning powder or scouring sponge, rinsed and dried.
2.) The surface cleaned in this way may not be touched any more with the fngers. The strip conductors and lands for soldering which shall be maintained after engraving will now be designed by means of a touch-up applicator (e.g. Edding 3000, Edding 400 etc.) on the copper side. You may also use another pencil with another lacquer (nitrocellulose lacquer). Adhesive symbols which are rubbed directly onto the board are very suitable, too.
3.) If the board has been prepared so far, it can be engraved. For this purpose dissolve the attached etchant (Ä100) in approx. 0,5 l of warm water (approx. 50°C to 60°C) acc. to the instruction. Fill the enclosed working bowl to the half with the etchant and place the board into with the copper side upward. Now the etch bath has to be moved slightly and continuously in order to accelerate the etching process. As soon as all copper surfaces which are not required are removed through etching, take the board out off the etch bath and rinse thoroughly under running water. Afterwards remove the lacquer from the remaining strip conductors by using a household cleaning powder or abrasive paper as described in 1.). The copper tracks are now blank and may be soldered.
4.) Holes can be drilled now and the board can be equipped then.