My worry with that would not so much be the spacing, that should be fine,
but i would be afraid the socket would come off if pulled on ;-)
0.4mm should still be possible with TT, that's just under 8/8mil rules i
think. The problem is with those metric spacings the printer must "round"
to the next full pixel, and i have found it is required to make the pads
rather narrower than the spaces, to avoid problems.
BTW those throughhole pads in places seem VERY small with that size of
hole in them, compared to the trace the rings are tiny. I don't think that
is such a good thing with non-PTH boards.
Also, i notice you cross-hatched the ground plane. Why?
ST
On Fri, 07 Apr 2006 11:16:16 +0200, leon_heller
<
leon.heller@...> wrote:
> I've just uploaded my latest PCB. It's a prototyping board for the
>
> Siemens MC55 GSM modem module. The tricky part about it is the Hirose
>
> DF12 50 way socket for the MC55, it's tiny with 0.5 mm lead spacing.
>
> I've used that sort of spacing with ICs like the Philips LPC2016 ARM,
>
> but it took some time to get the transparency right - I had to reduce
>
> the pad widths slightly to get adequate clearance between them.
>
>
> Hirose makes even smaller sockets with 0.4 mm lead spacing, I doubt if
>
> I'll be able to manage those, unless I get the artwork printed on a
>
> really high-res printer.
>
>
> The pic is here:
>
>
> http://groups.yahoo.com/group/Homebrew_PCBs/files/PhotoEtching/Leon/
>
>
> Leon
>