Sciencemadness Discussion Board

Tinning PCB

anoopai - 3-1-2011 at 07:53

What is the easiest method to apply tin to home made PCBs ?

urbs - 3-1-2011 at 08:05

IIRC, the solution that I used was Tin Chloride, a bit of sulfuric acid and Thiourea. The Tin Chloride I made since I happened to have some mossy tin, (don't ask), and ordered the thiourea. You might be able to use one of those liquid silver tarnish removers since they have a bunch of thiourea included. Make the solution as you need it since it won't store. Do a search for electroless tinning.

http://books.google.com/books?id=m8sJBIMtETgC&pg=PA318&a...

thanks

anoopai - 3-1-2011 at 08:33

thanks urbs , but its stannous or stannic chloride ?

anoopai - 3-1-2011 at 08:38

ok its stanous chloride

http://www.finishing.com/0200-0399/260.shtml

IrC - 3-1-2011 at 19:45

I would look into electrochemical methods. I used to build hundreds of boards and the method you are looking at sucks. You need the copper super clean, free of oxygen and hydrocarbons. Green scrubby pad (no soap type) in hexane or trichlor to clean works. After you finish it will still suck so bad most often it actually interferes with soldering. If you plan to do many and/or of high quality learn to electroplate. But still clean well first.


Twospoons - 3-1-2011 at 19:50

I found the easiest way is to paint the board with liquid flux (essential !), then use a piece of desoldering braid, full of solder, wrapped around your soldering iron tip, and basically paint the copper tracks with solder. Results aren't especially pretty, but with care you end up with a flat 'tinned' surface that won't oxidise, and solders very easily.

Arthur Dent - 5-1-2011 at 05:18

This is the stuff I use:

http://www.lpkfusa.com/boardfinish/tinplating.htm

It's a mixture of fluoroboric acid, Stannous fluoroborate and thiourea. It works incredibly well. You drop any cleaned-copper PCB in this solution and in minutes, you have a perfect, uniform coating of tin on your traces.

Robert