On Aug 12, 2006, at 4:37 PM, Jeff Walther wrote:
Yup, get ready
to solder .2 mm balls on 800 balls BGA.
Get your toaster-oven ready ;-)
BGA components have a specification for the clearance between the chip
package and the circuit board after soldering. I don't think you
could meet that just by putting the thing in the oven.
Very true...but I've looked far & wide for a reason for that
specification to exist, and have found none. The only thing I can
think of is the possible flattening out of the balls causing them to
short against adjacent ones...but is that really possible? Not sure.
I don't know how one reballs BGA components
though. Anyone care to
explain?
One "reballing" kit that I've seen has very thin metal "masks"
which
you place over the chip, and you slather solder paste through that with
something that looks like a squeegee. It's similar to applying paste
solder to a PCB with a stencil. I don't know how effective that method
is.
-Dave
--
Dave McGuire
Cape Coral, FL