Etching Place the PCB in the etch tank.  The etch tank is a tall, thin tank that contains the etching chemical.  Common etching chemicals include Ferric Chloride and Ammonium Persulfate.  The tank also contains a heater and bubbler.  The bubbler pumps air through the tank to agitate the chemicals to speed up the etching process.  Etching typically requires 3-5 minutes with a fresh, heated solution.  TIP - Ammonium Persulfate is a clear etching chemical that produces less caustic vapors than Ferric Chloride, is easier to clean up, and doesn't stain.

PCB in etch tank and after etching process is complete.


Tin Plating After etching, the ink left on the board is removed with a solvent such as MEK or Acetone.  The exposed copper is protected by placing the board in a tinning solution or Fluoboric Acid.  The solution will cause the copper to change colors to a silver or tin color.  Tinning improves the solder ability of the board, prevents copper oxidation, and gives the PCB a finished appearance.




PCB after tinning. 


Drilling / Sizing The final step to creating the PCB is drilling holes for mounting the through hole components and connectors.  The use of surface mount components greatly simplifies the final construction of a PCB.  In addition, surface mount components allow for smaller designs, elimination of potential socket failures, and a wider selection of components.