On 2/1/07, William Chops Westfield <westfw@mac.com> wrote:
> On Jan 30, 2007, at 11:36 PM, Vasile Surducan wrote:
>
> > Are you complete satisfied with your LPKF system ?
> > I mean did you try 6 layers boards with it ?
> >
> > I want to buy a complete system this year.
> >
> I bought a used LPKF from eBay a couple years ago for hobbyist
> usage.  Less than half the price of the cheapest new unit...
>
> I don't know if it was worth it.  I'm pretty sure I'm still far
> behind where I'd be $-wise if I'd sent every board I've made
> (including the N iterations of some of them) to a professional
> fabricator.  It's nice to be able to go from eagle design to
> SS PCB in a couple hours, especially for the tiny boards that
> aren't quite right that I tend to make, but often the several
> hours of baby-sitting needed don't come along for quite a while,
> and I could've sent them out.
>
> It's a pain not having Plated through holes.  Yeah, the newer
> systems have some PTH system of somesort, but it adds to the
> time and complexity of fabrication...
>
> It's a pain not having a soldermask.

My purpose would be proffesional PCB prototypes not hobby usage.
That means I need at least 4 layers (but often 6 layers isn't enough)
The soldermask tool is here:
http://www.lpkf.com/applications/rapid-pcb-prototyping/working-examples/solder-mask.htm
 Take a look to the catalog.

>
> Tools and other expendable items are expensive; you can buy surplus
> partially used drills for cheap, but the mechanical etching bits are
> uncommon, without many providers, and rather expensive (and they
> wear out pretty quick.)
>
> I have my doubts about it working very well below about 1mm pin
> pitch.  While the specs say you can get 0.2mm isolation (with the
> standard tool), you're looking at a V-shaped trench, so if you
> were hoping to do .5mm TQFP with 0.3mm lands 0.2mm apart, you're
> at the very edge of possible, and you get a pattern in the third
> dimension that is exactly wrong for helping to position the packages.
> (trenches for the leads to fall in, between the pads.)  Did I mention
> that it's a pain not having soldermask?

Yes I need 0.5mm BGA and TQFP

>
> Steps for more than 2 layers would add additional complexity and
> cost.  Did I mention that it's a pain not having PTH ?

There is PTH too with electrochemical plating or with chemical rudimentary tool.
see the catalog.

Thanks for your feedback.

I would appreciate also a link to other CAM/complete PCB prototyping
lines including PTH.

>
> It's really noisy.  I think they rig the trade-show demos where it seems
> to run at only "moderate" noise levels.  Or maybe the vacuums have
> gotten
> better since the one I have.
>
> On the bright side, it's a pretty good CNC drill even if everything
> else stops working.  You can easily have complex board outlines and
> internal cutouts and such that are rare to find in "prototype" PCB
> houses.  You can do signs and (2D) CNC-router type projects other
> than PCBs.  The software works ok, isn't hard to use, and seems to
> offer capabilities far beyond "free" stuff (like EAGLE's OUTLINES.ULP)
>
> BillW
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