[SBE] IR vs HotAir BGA rework stn?

[Kim Sacks]

Yes, BGA's (and bump packages) totally cover all of the solder pads.
Inspection of these solder joints can be rather tedious and is
generally done with a special x-ray machine, at least in production
assembly houses. Ideally an IR reflow oven would work best. However,
soldering a BGA can be accomplished by using a "hot plate" and a
variable air flow hot air pencil set to the lowest airflow position.
The hotplate enables even heating of the board from the bottom, which
is important with bump and BGA packages. I have done the propane torch
trick as well, but this has it's own problems as temperature isn't
easily controlled. If at all possible avoid using lead free (ROHS)
solder, as it will just cause problems. You can also find BGA stencils
and use a solder paste, I've had the best results with this, rather
than trying to hand tin the pads. There was great article in EDN (I
think) about this a few years ago - I'll have to see if I can find it.

Kim Sacks, KB3MZX
http://youtube.com/user/RadioCtrlDWife
www.optimod.fm
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(301) 880-7109


On Thu, Oct 15, 2009 at 11:46 PM, Jeff Carter <sbe at hidden-valley.com> wrote:

> This may sound stupid, but aren't the BGAs the ones that sit totally

> over and on top of the connections?  How do you ever inspect those

> once you've done them?

>