On Mon, Oct 17, 2011 at 4:26 PM, M.L. <m@lkeng.net> wrote:

>  You need 4 layers minimum and filled micro vias if you're going to do
> fine pitch BGA correctly. Yes, there may be other methods.
>
> 6 or many more layers for larger devices.
>

Yeah :( The Nexys 2 board that I have, which uses the same Micron pSRAM chi=
p
that i was looking at, uses 4 layers, consisting of 2 signal layers and 2
power layers. I don't know exactly what kind of vias they're using.

I'm not going to mess around with BGA until I find some poor prof's funds
for which I can use to make multi layer PCBs, with fancy vias and stuff.
(jkjk)
--=20
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