[time-nuts] Parts Selection

[Chuck Harris]

Bob Paddock wrote:
...
> BGA's are actually easier to do than QFN parts, as long as you  accept
> the board is now not repairable and is a throwaway item.
...

BGA's are about as easy to rework as anything else.  You use a hot air
rework station, and an underboard preheater.  The hot air rework station
has a manifold that constrains the hot air to heat the entire top surface
of the BGA, and when the solder melts, the chip will pop right off.

The big problem is you cannot readily re-ball a BGA part if it turns out to
be good, and you want to reuse it.  Re-balling machines are rather expensive
things.  You must do a good job of wiping away the old solder from the pcb
while it is still hot, and clean up the left over solder debris, and flux.

If you look on youtube, there are quite a few videos showing guys replacing
video "cards" on laptop computers.  They are all BGA, and the videos give a
good idea of what is involved.

-Chuck Harris