[Arm-netbook] iMX6 EOMA-68 CPU Card

[luke.leighton]

On Wed, Feb 27, 2013 at 9:46 AM, joem <joem at martindale-electric.co.uk> wrote:
> On Wed, 2013-02-27 at 00:43 +0000, luke.leighton wrote:
>> http://rhombus-tech.net/freescale/iMX6/news/
>>
>> auto-route success!  next on to design validation (clearance etc.)
>> illustration of what an actual iMX6 EOMA-68 CPU would look like has
>> been made.
>>
>> last bits needed: confirm the true PCB size (believed to be 47.5 x
>> 78mm) with litkconn.... who don't *have* a "recommended PCB layout"
>> (!!) so i am dragging it out of them through a well-known process
>> colloquially referred to in the technical trade as "20 questions".
>> the board can then be padded out (much easier than trying to reduce
>> its size)....
>
> Very impressive!
>
> A few questions for my reference:
> 1. What via hole sizes do you use inside the BGA area?

 10mil. i think i made it 10mil with a very narrow surround

> 2. minimum track widths in that area + track clearances

 under the CPU i made it 6mil.  then outside i think i allowed 4mil.

> 3. Clearances for the BGA pads, and
> 4. Clearances for the via

the DDR3 RAM is preexisting so i had to leave it alone, some of that
is 4mil with 5mil clearance.