[sdiy] What the heck is this for?

[Magnus Danielson]

> Hi,
>
> Joe Grisso wrote:
>> Those look like solder paste masks for SMT devices. You can use
>> those for single chip placement for doing SMT parts. You apply solder
>> paste to a small squeegee, place the mask over the pads on your PCB,
>> then squeegee the paste down. Once the paste is down, you place the
>> part on top of it and then heat up the solder with a hot air pencil.
>
> Most of those masks are for BGA parts - good luck soldering those
> with a hot air pencil!

BGA parts does not need solder paste, but it does need fluss.

Soldering larger BGAs do work with hot air, if you have a large enought
source, the guiding nozzles and also pre-heat the board. That and some
mechanical guiding is what constitutes a BGA soldering station. Works
fine.

Cheers,
Magnus