Homebrew PCBs

another interesting link:

http://www.electronics.dit.ie/techprocs/p_c_b.htm

Two sections are very interesting:

An electric motor spins a shaft enclosed in a tubular barrel 18 inches long 
containing holes perforated on the circumference from top to bottom. The 
motor and tube are vertical from the top of the tank so as when switched 
on, the motor spins the tube and stirs the solution. The effect is to 
suction of the solution into the barrel and to spray the board being 
etched.


>> (this is the rotrary sprayer we discussed before)



Tin-plating (optional)

This is done to provide a nice finish and to protect the copper from 
oxidization; also soldering will appear neater and will flow better.

A solution made up of fine tin powder mixed with water is poured into a 
basin. The copper is cleaned to a shiny finish be rubbing using a rubber 
supplied with the kit. The board is placed in the solution for 10 minutes. 
The board should then have a silver finish.


>> (What? tin powder in water? how does this work? really?)


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