MEK is in the same family (ketones) as acetone. Ketones are molecules
consisting of two alkane chains (like methyl, ethyl, butyl, propyl, etc.)
joined by a carbonyl group (carbon double-bonded to an oxygen). MEK has
somewhat higher toxicity than acetone but it isn't all that nasty (compared
to benzene or the chlorinated methanes). I think it was banned because it
is a persistent environmental pollutant.

I am very surprised that you were able to use MEK to dissolve IC packages.
Did you heat it up to do that? How long did it take?

I have done some IC "de-capping" and the only way I've learned to do it is
using either concentrated hot nitric acid (works quickly - in about 5
minutes) or concentrated hot sulfuric acid (takes much longer, about an
hour).

On Fri, Dec 8, 2017 at 2:56 PM, Jean-Paul Louis <louijp@gmail.com> wrote:

> I read all about those solvents, and I am surprised that no-one has yet
> mentioned MEK (Methyl Ethyl Ketone). I used it long before it was banned
> from Manufacturing Floor. Mostly was to dissolve epoxy packaging on IC
> before
> doing a die inspection with electron microscope. Also used to dissolve
> potting
> compound for some very critical repairs.
>
> That was a real nasty solvent, but we used good precautions like gloves,
> masks and vented hoods above test area.
>
> Just another $0.02,
> Jean-Paul
> N1JPL
>
>
>
> > On Dec 8, 2017, at 7:31 AM, Sean Breheny <shb7@cornell.edu> wrote:
> >
> > Bunny suits?! That seems a bit over-the-top unless this was an
> application
> > where you were spraying large quantities (several liters) into the air.
> >
> > I obviously have not done independent research on this - I am only goin=
g
> by
> > what I've read in MSDS and other published sources that I read before
> using
> > these chemicals. The US Centers for Disease Control lists the IDLH
> > (Immediately Dangerous to Life or Health) threshold at 500ppm for both
> > benzene and toluene but they allow up to 100ppm permissible exposure
> level
> > in the workplace for toluene but only 1 ppm for benzene. They also do n=
ot
> > mention any risk of cancer for toluene but they do for benzene. So, I'm
> not
> > saying that toluene is just dandy and no precautions are needed, but
> rather
> > that it is considerably safer than its "parent" molecule benzene for
> > long-term exposure.
> >
> > I also just learned that toluene is a significant risk to pregnant wome=
n
> > with regard to possible miscarriage so I guess it can be very nasty for
> > some people.
> >
> > Sean
> >
> >
> > On Fri, Dec 8, 2017 at 4:13 AM, <alan.b.pearce@stfc.ac.uk> wrote:
> >
> >>>
> >>> Toluene is also not all that nasty. It is methylbenzene but the methy=
l
> >> group
> >>> seems to prevent most of the carcinogenic action. Maximum safe
> short-term
> >>> dose is less than acetone/isopropanol.
> >>>
> >>
> >> Well, that doesn't equate to the hoops we had to jump through to use a
> >> toluene based conformal coat on our PCBs. A suitable booth with high
> volume
> >> air extraction and use of full bunny suits while handling it.
> >>
> >>
> >>
> >> --
> >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> >> View/change your membership options at
> >> http://mailman.mit.edu/mailman/listinfo/piclist
> >>
> > --
> > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
>
> Just my $0.02,
>
> Jean-Paul
> N1JPL
>
>
>
>
> --
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>
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