Maybe the sandpapered effect is caused by etching? This happens when
resist lifts during etching. Lifting can be caused by either ironing
with too low a temperature or insufficient cleaning of the copper before
ironing. I clean with a solvent first to remove fingerprints and such,
then scrub with 0000 ("four aught" = very, very fine) steel wool.
the problem is that i've clean it very good before i started.
first i've cleaned the PCB with acetone to remove fingerprints, then
i've put it in ferric chloride for about 1-2 minutes, then i've clean
it with an dry absorbant paper, and only then i've ducktaped the PnP
to the PCB.
Maybe it was the iron temperature ... first i've ironed it at
"syntetic" mark for about 5 minutes, then for another 3 minutes at
greater temperature (next mark on the iron dial). Is possible that
i've lifted the PnP, i don't know exactly ... btw, i'm using White PnP
because is cheaper then the Blue PnP, i do so because nobody was able
to tell me what is the difference betwen those two except "the blue
one is better" why? nobody can tell ... maybe is the price (the blue
one is 3 times more expensive then the white one).
Anyway ... i will keep trying 'till I finish my White PnP stock ...
then i'm going to try another method ... i heard that UV sensitive PCB
is "the one" ... if is not too expensive ...
PS i find somewhere something about using spray acetone after, when
the circuit is imprimed on PCB, it seems that the toner is going to
stick to the copper better and is going to fill the eventual gap or
line interruptions ... anybody heard something like that?
(
