Re: 1mm BGA virgin

On Oct 16, 12:43 pm, Simon <goo...@xxxxxxxxxxx> wrote:

So:
o Is there a PCB manufacturer who can drill tiny vias like this ?

Yes, but they are not cheap. Last time I checked, 6 mil was quite do-
able.

o Am I doing this wrong ? Better: How am I going wrong ? :)

Looking at your board, you are routing power and ground, and not very
well at that. I would recommend using power planes; they don't add
that much cost to the boards, especially now that you can't use the
cheap-o houses. Failing that, do it as a grid/flood, and don't use 2-
inch traces to avoid a via.

Also consider 'via in pad' construction. Modern plating/soldering
techniques allow this (previously, the problem was flux entrapment,
that can be overcome.)

o What SMT pads / via sizes would you use for a 1mm BGA part ?

19 mil (0.47mm) is a typical pad size for fine-line BGAs. Vias can be
the same size as the pads. (19mil pads on a 1mm grid with vias
centered gets 9mil clearance. >6 is acceptable.)



Look for Altera's AN114. It has a bunch of good info about using this
size part.

If you're going to try and position/solder a fine-line BGA by hand in
a toaster oven, you're braver than me. Good luck.

Alex.
.

Relevant Pages

  • Re: What software do you use for PCB with FPGA ?
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  • Re: What is the Best PCB Layout software ? (Money no object)
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  • Re: heatsinking a thermal padded IC ?
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  • Re: placing addiional caps across existing caps to reduce noise
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