Spehro Pefhany wrote:
>>Interesting.  But that still is *some* money, so you would put them all
>>on one side unless you had a reason to do otherwise, right?  That seemed
>>like the OP's question.
>
> The PCB can certainly be smaller and possibly can have a better layout if
> you put parts on both sides. This is particularly true when there are more
> than two layers. Unless you are fixed to a certain size of board (eg. by
> corner mounting holes, grooves or clips), the cost savings from reducing
> the square inches of a multilayer board will likely overshadow
> the additional cost of placing parts on both sides (eg. using the adhesive
> method before reflow).
>
> With 2-layer boards you may wish to do a quasi-single-sided
> layout in order to maintain a partial ground plane under the parts.

Spehro is right. The only reason we have a board that's populated on both 
sides, is we are constrained by the enclosure we're using, and the sheer 
number of parts, which would not fit on one side.

I was arguing that contrary to what others have said, boards populated on 
both sides are common, and they're not "significantly more expensive" (IMO, 
of course it depends on the definition of "significantly"). One thing that 
is not debatable, is that most (if not all), board assembly houses would not 
have a problem with parts on both sides.

Vitaliy 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist