Erik,
Find a "hot house" garden center some where and leave them in there for a few weeks.
That should work!
David A. DOuthit
Manager
LoCan LLC
Eric Dawson wrote:
> David,
> I didn't go into too much detail because I didn't think the communication
> warranted it, but your admonition suggests I should.
> Firstly, we are a small integrated company with a Process Department of one.
> My facilities for this type of experiment are a bench (hard won through a
> bit of chicanery on my part), a Pyrex beaker (which I supplied myself) and
> access to hot water from the canteen.
> The actual conditions of soaking included total immersion in hot water,
> replenished on a daily basis, with added wetting agent. (Oh all right,
> washing up liquid) and also inverting a board with a BGA already soldered in
> place over hot water, replenished daily.
> I have also tried reflowing BGAs that have laid around the workshop for over
> a year with no moisture protection.
> And still I cannot deliberately pop corn the blighters.
> Regards
> Eric
>
> > -----Original Message-----
> > From: David Douthit [SMTP:[log in to unmask]]
> > Sent: Monday, November 18, 2002 7:31 PM
> > To: TechNet E-Mail Forum.; Eric Dawson
> > Subject: Re: [TN] Popcorning
> >
> > Eric,
> >
> > Congratulations! You have proved, once again, that water vapor is much
> > more permeable than liquid water.
> >
> > Try "soaking" them in a high humidity condition (>90%) at 40 degrees C
> > for 48 hours then running reflow.
> >
> > David A. Douthit
> > Manager
> > LoCan LLC
> >
> > Eric Dawson wrote:
> >
> > > Werner,
> > > I could use some myself for internal quality training.
> > > I have recently soaked some BGAs and some quad packs in water for over a
> > > week before putting them through a reflow profile. I have yet to produce
> > > visible evidence of pop corning.
> > > The annoying thing is, a while ago we used some BGAs on a tape where the
> > > moisture indicator went just a little pink and they pop corned. The
> > visual
> > > evidence was fat solder deposits and shorts in the middle of the package
> > > where it bowed downwards. My street cred. with the managers around here
> > has
> > > taken a beating since I have failed to reproduce the problem.
> > > Oh well, I'd rather be happy than right.
> > > Regards
> > > Eric Dawson
> > >
> > > > -----Original Message-----
> > > > From: Werner Engelmaier [SMTP:[log in to unmask]]
> > > > Sent: Monday, November 18, 2002 4:02 PM
> > > > To: [log in to unmask]
> > > > Subject: [TN] Popcorning
> > > >
> > > > Hi 'Netters,
> > > > Could any of share some good pictures of a 'popcorned' component and a
> > > > component with delaminated die. I would of course give full credit as
> > to
> > > > source.
> > > >
> > > > Thanks,
> > > > Werner Engelmaier
> > > >
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