Matthew

                As a reformed smoker, who subsequently doesnt know that
     much about it, I would assume that smoking can indeed be harmfull to
     the health of your boards.

                Im guessing a bit here, but, from the yellow stains on the
     ceiling of the Yorkshire Grey down the road, smoking most certainly
     gives off "solids" in the exhaled smoke, and this is prone to settling
     on whatever it contacts.  assuming that this is tar? or what ever the
     new buzz word is for the stuff, its going to contain Carbon, Sulphur
     and other nasty things.

                Assuming that this lands on the board coverings (tissue
     paper) its probably going to penetrate through and end up on the
     boards themselves,  how this would effect reflow is an unknown but I
     doubt that it is good,  also once the stuff gets on the board, SIR and
     many other things may also go to the wall.

                From both solderability, and reliability point of view,
     both C and S in high contents, or stubbon layers are bad, and as the
     residue from smoke appears to be more of a high viscosity liquid (from
     the solids, that combine with moisture in the air) I would'nt hesitate
     to say that keeping the boards near a chimney is not good for them!
     An alternative way to look at it is this,  PCB suppliers go to a heck
     of a lot of effort to ensure that they ship us good, clean and dry
     boards, the least we can do is try and keep them that way

                Run some tests, ask folks to smoke all over them, and see
     what happens,  Im sure we would all be interested in the results, and
     you could even get an environmental or lifesaver award for reduced
     mortality rates.

                Good luck
                    Roger





______________________________ Reply Separator _________________________________
Subject: [TN] Cigarette smoke, PCBs & its harmful effects?
Author:  "TechNet E-Mail Forum." <[log in to unmask]> at #email
Date:    26/03/99 14:09


Hi there everyone, at my company we are currently reviewing our smoking
policy.

What I am wondering is if anyone has any information on the effects of
cigarette smoke on printed circuit boards.

We have recently moved all our PCB's out onto the shop floor so that
they are next to the soldering department, so that
they have less going backwards & forwards to get them, after all its
them that use them.
Personally I think that this has been a bad move, as now they are on
shelves, next to dozens of women who smoke.

I already know that its not a good idea to have "years worth" of PCB's
on the shelf, open to the environment, without much more than
a tissue paper covering (at the best). but can fag smoke do anything to
the PCB's?

Now I'm not suggesting that they can get the big "C" but can it affect
their solderability etc?


T.T.F.N

Matthew Lamkin
Printed Circuit Board Draughtsman
Protec Fire Detection PLC
Churchill Way,
Nelson, Lancs
BB9 6RT.
Tel 01282 717393
Fax 01282 717273
Email = [log in to unmask]

Company Web Site = http://www.protec-fire-detection.plc.uk

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