At 11:55 AM 20/12/2010, you wrote:
>At 06:09 AM 12/20/2010, Olin Lathrop wrote:
>
> > > Maybe he wants to make/have it made single sided
> >
> >Why?  In very high volume single sided punched boards can save a little
> >money, but this is clearly a hobby project.  The board house will use a =
2
> >layer process even if you just use copper on one layer.  It's not cheape=
r to
> >make a 1 layer board than a 2 layer board, so you might as well get the
> >benefit of a ground plane or easier routing.
>
>My main board supplier definitely charges significantly less for
>single-sided boards.  These are boards that we order in 500pc or
>1000pc lots and we do a total of 6000 to 10,000 single-sided boards per ye=
ar.
>
>Actual price difference to me is about 35% less expensive for single
>vs double-sided boards but that figure includes shipping charges from
>China.  Actual PCB cost savings is considerably more when you take
>the shipping charges out of the equation.
>
>My best guess is that the cost is less because they don't have to do
>the process for plated-through-holes - but that's just a guess.
>
>dwayne

IME, different factories or at least production lines are used for
single and double-sided boards when supplied in quantity. If you get
quotes for single-side boards from domestic companies that are set up
primarily to do double-sided, the price won't be much different. If your
niche is small lots of expensive stuff, that's fine. If you have to make
stuff as cost-effectively as possible in quantities in excess of (say) 5K,
then it would be irresponsible not to look carefully at single-sided boards=
,
despite the obvious(?) disadvantages. Punched boards can be even cheaper
because they avoid the NC drilling step AND routing (or shearing) step
(not generally compatible with conventional plated-through holes,
though you'll see exceptions like the boards in TV remote controls).

Double-sided and multilayer boards are typicaly quoted by the square
inch or cm^2, and single-sided by the square _meter_, which should tell
you something!


>Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the rewar=
d"
speff@interlog.com             Info for manufacturers: http://www.trexon.co=
m
Embedded software/hardware/analog  Info for designers:  http://www.speff.co=
m



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