[Arm-netbook] iMX6 EOMA-68 CPU Card

[luke.leighton]

On Wed, Feb 27, 2013 at 10:32 AM, luke.leighton <luke.leighton at gmail.com> wrote:
#>> 1. What via hole sizes do you use inside the BGA area?
>
>  10mil. i think i made it 10mil with a very narrow surround

 it's juuust about possible to do this, because freescale have a very
sensible rule of doing a 0.8mm pitch on BGA for precisely the reason
that many older PCB factories cannot do anything more accurate.

 less than 10mil drill, the bits have to be carbide, and they break;
less than 6mil clearance and they end up having to x-ray the board, or
just hope like hell.  also, below 6mil, BGA moves about, causes solder
to bridge across tracks and pads.  whoops.

  i *may* be able to use a little company in saffron waldon, it will
be touch-and-go because of the 5mil clearance on the DDR3 RAM.

 l.