[Arm-netbook] updates from eoma68-a20

[Christopher Havel]

Replying by phone, usual constraints. Sorry.

Your reply makes a lot of sense. I understand better now. That's quite an
operation...

On Jan 27, 2018 6:15 PM, "Luke Kenneth Casson Leighton" <lkcl at lkcl.net>
wrote:

> 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.
>
> _______________________________________________
> arm-netbook mailing list arm-netbook at lists.phcomp.co.uk
> http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook
> Send large attachments to arm-netbook at files.phcomp.co.uk