In a message dated 8/19/99 4:33:39 PM Central Daylight Time,
[log in to unmask] writes:
<< I'm a board fabricator that sub-contracts to an assembly shop to run
some boards through a reflow assembly shop. We've recently
(significantly) increased the volume of parts going through this
process. The assembly shop is complaining about a "noxious" odor while
runing these boards. While they are trying to figure out how to capture
the fumes, I'm trying to figure out what they are. I have an Industrial
Hygenest who can tell me how much of something's there, if I can tell
him what it his. MSDS's being what they are, I'm not too confident that
I'll be able to isolate all the possible candidates.
I figured from the worldwide audience of assembly experts on Technet, I
ought to be able to get a couple of ideas about what the odor might be.
Does anyone have any suggestions?
I'd also be interested if anyone knew of a lab that could bake a board
or two, capture and analyze any volatiles emitted.
Thanks in advance for any feedback. >>
Hidee-Ho there!
I have run across certain boards that did have a different sort of stink
coming out of the oven than others...and while I didn't worry about it too
much, or so much that I needed to analyze the odor composition, I thought
that it might have been partially cured mask as someone else has mentioned.
But what I did do, is check if the exhaust damper was opened the way it
should have been, and sure enough, someone had almost closed the thing. It
was a "butterfly" type of valve that I had in the ducting. Opened that up,
and no more stink...
I would wonder why one should smell much at all if the exhaust is operating
properly. I might also check if the exhaust is sufficiently rated for what
the oven requires. There is a minimum cubic-feet-per-minute flow required for
most ovens...I have a Conceptronic oven here, and we need 200 cfm at each one
of the two exhaust ducts, says so in the manual...if fact, Conceptronic may
void the warranty on your blower motors if you don't have that (the exhaust
is needed for cooling inside the bonnet where the blower motors are).
But that would be something I would definitely check (whether or not the oven
is exhausting properly) before getting a bunch of "sniffers" in there and
analyzing gases and whatnot...with my luck if I had somebody come in to do
that, they'd catch me on a day that I ate my Burrito "El Grande" at lunch
from down the street, and wind-up closing the place down for toxic gases!
(hehehe)...mmm, boy they sure are good though! (...but deadly...say, anybody
got any spare "Beano"?)
-Steve Gregory-
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