Ironic that the start of this thread concerned MEMS accelerometers, where
vibration sensing is the very reason you want to use them.

A drop of cyanoacrylate and short wires to the outer pads works just fine
to bond them to the board. You actually get better bonding since you have
more chip area glued than pad area soldered.
You get to the inner pads with wirewrap wire, and then coat the 'loose'
wires with hot melt glue (so it's easy to remove with a hot air gun).

Herbert Graf wrote:
>
> > Couldn't you solder it dead bug style - the chip upside down?
> >
> > /Hugo
>
> That certainly is possible, however if the part has alot of pins that could
> get quite ugly. Obviously I would also not be a very "strong" type of
> connection, so I wouldn't recommend it in any application that has the
> possibility of vibration. TTYL


> I am planning to get a mems gyro from ADevices.
> Can someone pls explain how to solder the ball pins
> that are underneahth the package. the ones on the
> periphery seem to be easy to solder. what abt the one
> underneath and inaccessible.

You could also look at putting vias where the BGA pads would be.
Then you could wick solder up larger than normal via holes to get contact.
Flux on the bga pads is ESSENTIAL for this trick to work.

Robert

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads