On Sat, Feb 28, 2009 at 02:21:23PM -0500, Stuart Brorson wrote: > > How often does the need for single-sided boards arise? > > The question about single-sided boards is interesting, but the > answer depends upon how you intend to fabricate your boards. > > If you're sending the boards to a PCB manufacturer, then the raw > material they use is fiberglass clad with copper on both sides. In > this case, it's senseless to ask for a single-sided board to save > costs -- they start with a double-sided board in any case.
However, some of them do provide a cheaper, single-sided service - even the low-volume "panellising" companies - for example, www.pcb-pool.com. If they are starting from double-sided stock, then they can save on the production of an artwork - just expose the "component" side fully (or not at all, depending on whether their photoresist requires a positive or a negative exposure). They can also save on through-hole plating. When I've used their single-sided service before, I just sent them my whole data file (yes, I know, I'm a sinner - I use a commercial PCB design package), and asked them to do just the bottom copper layer. > I agree that it tends to trip up newbies. However, there's one Gerber > file per (metal) layer, so you can always discard the back side file > without any problems. That's what I was going to say :-) > Finally, one of the projects slated for work under the Linux Fund's > PCB project is to update PCB's handling of layers. Things like the > ability to easily deal with single sided boards from inside of PCB > are part of the work to be funded by the Linux Fund. I'll just remind > everybody that they can make this work happen sooner by making a > donation! If I may make a suggestion - "solve" the layer handling problem which prevents PCB's data files from being taken directly by companies like www.pcb-pool.com. (I think it's something to do with the fact that the file doesn't contain any info to define the meaning of each layer (e.g. top copper, bottom copper, etc.) Gerber is such a vile format; it's time it was consigned to the scrapheap :-) -- David Smith Work Email: [email protected] STMicroelectronics Home Email: [email protected] Bristol, England GPG Key: 0xF13192F2 _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
