Tin Plating your circuit boards is important!

[GT Blocker]

Just a note for those making their own PCB's. If you want longevity out of your boards, coat them with tin. Non-tin plated boards will eventually corrode (sp? - jeeze, long day..) and fail due to cross-talk and down right shorts. Bare copper just doesn't hold up well to the environment.
Datak makes a tin salt product ( No.ER18 ) called Tinnit that works great, although other companies may make similar products. Heat the 'bath' up and soak the board for 30min or so. That's it.
I wish I could tell you what particular salts they use but I can't (I was a bit pissed off to find out that the positive etch resist developer I was buying was nothing more than diluted Draino (lye), so who knows what these folks use that might be nearly as easy to find...). Anyway, If you want a home-made board to last, TIN PLATE IT! If you just want a test board...never mind. Just my tin cents worth....

[hung]

Thanks for the info.
Can you provide a link?

[Max]

Just a note for those making their own PCB's. If you want longevity out of your boards, coat them with tin. Non-tin plated boards will eventually corrode (sp? - jeeze, long day..) and fail due to cross-talk and down right shorts. Bare copper just doesn't hold up well to the environment.
Datak makes a tin salt product ( No.ER18 ) called Tinnit that works great, although other companies may make similar products. Heat the 'bath' up and soak the board for 30min or so. That's it.
I wish I could tell you what particular salts they use but I can't (I was a bit pissed off to find out that the positive etch resist developer I was buying was nothing more than diluted Draino (lye), so who knows what these folks use that might be nearly as easy to find...). Anyway, If you want a home-made board to last, TIN PLATE IT! If you just want a test board...never mind. Just my tin cents worth....

Hi,
the solution is usually made of stannous chloride and other chemicals, acids... and works cool this way for small quantity and if you can do it in well ventilation area, otherwise not.

Often the product contain some "exotic" stuff like this:

http://www.sciencestuff.com/msds/C2854.html

So be careful using it. The boards could be also coated with protective varnish that's often practical alternative and also cheaper solution to tin plating.

Kind regards,
Max

[GT Blocker]

plating solution source

I usually get Tinnit from Allelectronics.com for $9.50 atm. One batch plates approx. 600 sq.in. Once mixed, the solution keeps about two months in a sealed container. The un-mixed powder will keep nearly indeffinately.

[Elie]

In a pinch, you can tin with solder. Watch the heat.

[Carl-NC]

For homemade boards, I clean them to a bright finish and spray with 2-3 coats of polyurethane. I've got 10-yr-old boards that still look new.

- Carl

[chemelec]

I just remove All the Solder Flux and leave the boards as bare copper. Some of my boards are over 30 years old and still work perfectly.

In my opinion, Removing Flux is More Important as it can become Conductive with any moisture.

I tried the Tin at one time and found it also oxidizes.
Especially if you live in an area with High Humidity.

[Max]

In a pinch, you can tin with solder. Watch the heat.

Hi,
I've done this way also for a couple of boards...

This way... after copper is etched I wash carefully with water... then use 10% HCl solution to polish from surface oxides.

Same could be done with flux stuff... and heat, but then remving it is a bit problematic.

Then I melt some tin-lead alloy in a small container... then when melt I let it pass over the copper... few at a time... with board inclined over a temperature resistant support.

To catch the eccess of tin-lead I've built a simple tool... an old soldering iron 100W plus a flat bronze armature... I use to heat up tracks... like removing water from a car glass...

With the aid of wet sponge all the eccess tin-lead is removed, leaving a shiny , thin layer of tin-lead over the copper.

I don't use anymore... cause it's a total waste of time: any board could be coated , once polished very well, with quality varnish and last for tens of years with no problems.

The only thing I miss from tin-plating is the extremely easy soldering of surfaces... cause the tin and lead oxides are very thin and are ideal for good soldering joints... copper has the bad tendency to create tick oxide layers that require eccess of flux for good soldering at joints. The problems can be minimized polishing very carefully before soldering is performed... but sometimes this isn't enough cause also some components are related to that problem,then flux is necessary in the mix.

Kind regards,
Max