Homebrew PCBs

Jan,

Just a word of comment: I tried the electroless tin and it workd 
exceptionally well on tinning the PCBs. I was quite amazed how well 
it work, exactly in a kitchen and I keep in tee fridge all the time. 
Life of the solution according to a mfr is six months and the cost is 
low for that amount of time.

However, I don't know what the electroless tin does to a hole- that I 
hvent tested but I suspect that unless the hole is copper, than 
nothing. 

It wasn't clear from your post if you were talking about tinning the 
copper traces or tinning the thruholes. For traces to be tinned, the 
solution needs to be hot, otherwise it takes very long time. Mike


--- In Homebrew_PCBs@yahoogroups.com, JanRwl@A... wrote:
> In a message dated 7/29/2004 10:23:09 PM Central Standard Time, 
> dave_mucha@y... writes:
> Any ideas on a a simple way to do plating 
> Dave:  Even IF PTH was no more hassle than etching a single-sided 
board, if 
> one DOES PTH the drilled blank successfully/adequately, THEN the 
ONLY way to 
> apply "resist" is to TIN-PLATE the desired pattern using 
a "negative" image of 
> "plating resist" which exposes only the desired tracks and 
the "insides" of the 
> holes, of course.  Then the tin plating resists the ammonium 
persulfate etch. 
>  
> 
> Sad, but MUCH more involved than basic double-sided copper boards!  
I tried 
> the "electroless tin-plate" one firm (Kepro???) once offered, and 
it worked, 
> but NOT very well, and required pre-heating of the liquid, and it 
PRECLUDED the 
> use of "kitchen utensils" as many of us do, AND, even if done a 
VERY long 
> time, the resulting plating was NOT totally "chemically opaque", so 
pin-holes 
> would result during etching, etc., etc.  Though boards plated with 
this 
> electroless tin stuff DID look much better than corroded ol' brown 
copper!  So I now 
> have any of MY boards done professionally, if I need ten or more of 
same board, 
> or gold fingers, and just "solder both sides" of lead-wires for 
those holes 
> that MUST "go through", or I use eyelets where absolutely 
necessary.  A pain, 
> yes, and not as "neat" as PTH, but what can we do?  PUNT!
> 
> Jan Rowland
> 
> 
> [Non-text portions of this message have been removed]