[Arm-netbook] updates from eoma68-a20

[Luke Kenneth Casson Leighton]

On Sat, Jan 27, 2018 at 10:45 PM, Christopher Havel
<laserhawk64 at gmail.com> wrote:

>> the problem is they need to be re-balled.
>
>
> Forgive both naïveté and apparent stupidity (or at least inexperience) --
> but why? A conductor conducts, be it a copper trace, an aluminum wire, or a
> lump of solder in between the two. What's a little solder reuse between
> friends?

 the solder balls on BGA and FBGA are specifically calculated to be a
size that will spread evenly and create a successful circuit, whilst
at the same time being of exactly the right size to support the weight
of the IC itself against surface tension and not get so squashed so
flat that they cause a short-circuit to the pad next door.

 when you REMOVE a BGA or FBGA IC from a circuit, that ball had
ALREADY been destroyed and obviously needs to be replaced.

 with a ball of the exact same size.

 that costs money and time.

l.