The simplest method, used for small-scale production and often by hobbyists, is immersion etching, in which the board is submerged in etching solution such as ferric chloride. Compared with methods used for mass production, the etching time is long. Heat and agitation can be applied to the bath to speed the etching rate. In bubble etching, air is passed through the etchant bath to agitate the solution and speed up etching. Splash etching uses a motor-driven paddle to splash boards with etchant; the process has become commercially obsolete since it is not as fast as spray etching. In spray etching, the etchant solution is distributed over the boards by nozzles, and recirculated by pumps. Adjustment of the nozzle pattern, flow rate, temperature, and etchant composition gives predictable control of etching rates and high production rates. COUNT 5
QSN1 What non-professionals might use immersion etching, since it's the easiest way to make a PCB? ANS1 hobbyists QSN2 If you wanted to speed up the etching process, you could agitate the bath up or add what to it? ANS2 Heat QSN3 Is the immersion etching process long or short compared to other production methods? ANS3 long QSN4 What funny name is used for the etching process where air is blown through the etching solution to get it moving around? ANS4 bubble etching QSN5 What's the fastest and most easily controlled process for etching? ANS5 spray etching