petrus bitbyter said:
Well Ross,
You should have had more PCBs in your hands then I had. I remember too well
the times I tried to clean PCBs with acetone and got the green laquer along
with the dirt I want to remove. So I did not use acetone but ethanol (or
WS11) ever since. Nevertheless, the next piece of PCB I got in my hands -
some minutes ago - did *not* let its solder mask solve in acetone. So I
think you are right and my response was based on the wrong experience. (Old
experience although <30 years.) So sorry for the mistake and thanks for your
reply.
petrus
Hi Petrus....
I have never used acetone to remove what they call soldermask on PCB's and
it might remove it somewhat. In my experience in that biz was if we
accidentally got it on the wrong area it could not be removed adequately to
make the customer happy. When the laser drills showed up, someone came up
with the idea to ablate soldermask. You just set the machine up to burn down
to the foil. The C02 laser typically won't burn through copper so it's the
perfect tool. They use these machines for drilling blind holes .004 and
smaller at extremely high speeds. First they use a yag laser to drill
through the copper, then they follow up with a C02 laser to cook the glass
down to the next layer of copper. Then they fill the impression with
electroless copper for a connection...
In any event, this message got way off topic!!!....take care, Ross