First thing that comes to mind, is to mask off the bottomside beneath the
footprint of the BGA with either a temporary mask, or kapton tape to prevent
secondary reflow...
are there unmasked vias beneath the BGA?

Most likely, there's going to be decoupling caps real close to the BGA, so
that's going to be a problem...you may have to install them manually after
wave...

Love it, 10-lbs inna 1-lb bag...you know what I mean.

-Steve Gregory-

> Hi guys
>     We pilot run a batch of double assembly board with BGA on top
> side.After wave soldering we found the one side of BGA sank and ICT test
> reported short.Can anyone recommand the design and process guidelines
> passing wave soldering.For example the limitation of BGA ball tempature.
>
> thanks
>  welton.w.don
>