Em 20/12/2010 13:07, Olin Lathrop escreveu:
> Kerry Wentworth wrote:
>> It really isn't that hard.  Print the artwork on to magazine paper
>> with a laser printer, transfer to copper clad using a laminator, and
>> etch.  I can reliably do .5mm spacing, which is as small as I can
>> comfortably do hand soldering.
> Note that's a whopping bit 20 mils.  Your not going to do a .65mm (26 mil=
)
> pitch QFN package with that as the OP is trying to do.  He either needs t=
o
> use a larger package or have the board professionally made.
>
> Maybe someone that's really really good with homemade PC boards can do th=
is,
> but that's going to take some experience and experimenting at best.
>
>
> ********************************************************************
> Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
> (978) 742-9014.  Gold level PIC consultants since 2000.


The nearest PCB manufacturer is 500mi away from where I live. When I
order boards from them, I have to spend at least $200 plus 10 business
days to have the boards.

It happens that in my city there is a small company that makes metal
stamps for the graphic industries, and their process is also adequate
for PCB making.
When I need urgent prototypes, I just e-mail them a post-script file in
the morning and I receive the boards in the afternoon, for around $10 each.

They just etch the board, no holes or plated holes, I simply ask an
assistant to drill the holes. Double-sided possible, but the alignment
may be tricky. 0.5mm pitch perfectly usable.

Their service is the only possible way to have a working prototype in
one day around here.


Isaac

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