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PCB questions

ReachReach Posts: 107
edited 2014-01-24 09:34 in General Discussion
I am extending my knowledge and trying to layout a PCB with an ARM9. This is a 324-ball TFBGA package that runs at 400Mhz

My questions are.

How many layers are typical using this higher speed ARM chip.
Who can I call to make the actual PCB in small quantities I am looking for 5 to 10 pieces for testing.
How the heck do you layout the traces within the small grid?

Comments

  • Mark_TMark_T Posts: 1,981
    edited 2014-01-22 17:36
    I suspect (don't know) that 6 layer is required to route the signals out of the BGA, given you need upteen
    decoupling caps on the board reverse. Sometimes datasheets suggest a routing for the package.
  • WBA ConsultingWBA Consulting Posts: 2,934
    edited 2014-01-22 17:58
    1) 8-12 layers would be typical for that package.
    2) You will need to find a fab house that can handle your design once you know your minimum trace width and spacing. (PCB Fab Express and Advanced Circuits are decent proto shops with good abilities)
    3) The manufacturer of the chip should have documents recommending layout and escape routing for their chip. Attached is a document that explains a bit of it, check out pages 127-133
  • TubularTubular Posts: 4,703
    edited 2014-01-23 15:34
    Very nice guide, thanks WBA
  • ReachReach Posts: 107
    edited 2014-01-24 09:26
    Thanks WBA for the PDF Im reading it today. Anyone know of a good board house other than Advanced circuits? I find them expensive for prototypes & considering there constraints (4 layer max). I will look into PCB FAB express.
  • PublisonPublison Posts: 12,366
    edited 2014-01-24 09:34
    Reach wrote: »
    Thanks WBA for the PDF Im reading it today. Anyone know of a good board house other than Advanced circuits? I find them expensive for prototypes & considering there constraints (4 layer max). I will look into PCB FAB express.

    Advanced Circuits, (a past customer of mine), will do 30-40 layer. First page of this pdf.

    C
    an't comment on the price, but they are a top notch board house.
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