Re: gEDA-user: Baking chips to dehumidify before reflow

[Steve Meier <smeier@xxxxxxxxxxxxxxxxxxx>]

>From http://www.epsondevice.com/semicon_e/c_support/ic_hadling_2.html


Package baking conditions
                                    
Packages which exceed the
recommended storage conditions
should be baked before re-flow
soldering. This baking process will
prevent the resin from cracking or
losing ad-herence during soldering.
Meanwhile, baking should be done up
to 2-times under the following
conditions.


Drying conditions for standard IC
packages
         Drying temperature
            Drying hours
            125 + 5 ÂC 
  20 hours or more and 36 hours or
                less



On Thu, 2006-06-08 at 09:58 -0400, Peter TB Brett wrote:
> Randall Nortman wrote:
> > I've got some LQFP chips that I've been storing, with the bag opened,
> > for a bit longer than I really should have.  The indicators on the
> > humidity cards have started to turn pink, so I'm worried that they
> > will have absorbed too much humidity and if I try to reflow them now,
> > they'll "popcorn" (i.e., trapped moisture turns to steam and
> > evaporates, cracking the package and/or die).  Anybody have any
> > suggestions on the best way to do this using common household
> > equipment?  I guess I just stick them in an oven at lowish temperature
> > for a while, but what temperature and for how long?  I checked the
> > datasheets for the chips (Atmel AT91SAM7X256 and Micrel KS8721CL) and
> > didn't see any useful information.
> >
> 
> You could try putting them in a sealed container with some bags of silica
> gel for a few days.
> 
> Peter
> 
> --
> Quake II build tools: https://adidas.servegame.org/projects/buildutils/
>