pcb electro plating

[paku5535]

hi guys
the picture uploaded below is a circuit for a buffer. after etching i did tin electroplating on it. since in our locality there is no such liquid tin.

how ever the result of the plating incomplete. the ground plane was tinned but the inner tracks were not tinned. i have tried it for so many times.

my suspection is that may be this is because of loop in the ground plane?? or something else. is this good to keep loop in ground plane.

plz loot at the text also. the texts that were very closed to the ground plane got tinned. what's happening!!!
plz help
thanks

[J M Fahey]

The inner tracks are not tinned because they are not electrically connected.
You should add a very thin track joining them, and after electro tinning remove them (or everything will end up shorted).
Scratching with an X-acto knife is as good as anything else. 
Please post your process here, it´s interestring.

[paku5535]

is there no other alternatives?

[J M Fahey]

If you electro tin you need electrical contact.
You already proved it yourself: the couple letters that got tinned were touching the ground track, those which didn't , were not.
What I used often in the old times was a chemical (non electro) plating solution which usually jewellers sell.
It's inexpensive and a small bottle lasts a lot.
You just clean and dry your PCB, polish the copper a little with some steel wool, mainly to make sure there's no trace of oxide or grime on it and wipe it with a piece of cotton with some plating solution.
Looks very nice, although the silver layer is thin.
Takes solder very well.
What I use now to protect copper is some pine rosin dissolved in alcohol, which I keep in a discarded glass jam pot, lasts forever but remember to cap it tightly.
I "paint" the copper side with it but need to whack the board afterwards against a table (over some newspaper sheets) to let holes free.
There's people that just wipes the copper side with this solution, but the rosin layer is very thin fine if you will use it within a few days; mine protects it for years.

[tonyharker]

What you need to look for is SENO tin powder.  A chemical when dissolved in water will tin plate PCBs in a few minutes.  Made by a company in Germany I believe.

[gbono]

Imersion tin plating finish is used extensively in the manufacture of PCBs this avoids the electrolytic plating requirement that all plated targets be electrically connected as you found out.

http://eshop.engineering.uiowa.edu/~eshop/msds/11123.pdf

[joecool85]

Why do you tin the PCB?  Is it just to preserve the copper?

[gbono]

Remember that the current lead free solder is almost completely tin.

[joecool85]

So actually now that I think about it, not only do I want to know why you would do it, but how?  It looks really cool and I might want to try it just for giggles.