>If you can say definitely that you can do
> fpga boards with 8mil tracks and spacing over the lifetime of the printer,
i'll
> shut up. Also, can you get good alignment for 1mm via pads when doing
double-sided
> PCBs? (thermal expansion problems). With the right inkjet, i can make
perfect
> (15x15cm) double-sided boards with 0.8mm track and spacing and 64pin 0.1"
connectors
> with no alignment problems with 0.8/1.0mm via pads. I do get some breaks
and
> shorts because of dust or "stuck" resist. Suitable inkjets (like epson
stylus colour)
> go for $5 or give-away on ebay while lasers cost a lot more.
Russell,
Where are you finding these $5 and give away printers on E-Bay? I have been
looking for a cheap one to tear apart and try the inkjet straight to a PCB
idea that was on this list earlier.
With a laser printer, I have gone down to 7 mil track and spacing. I have
never needed to go smaller than this on traces and it works fine. I have
never had to deal with breaks or shorts from a laser print. There is some
distortion on larger boards near the end of the print, but if you print in
the same direction from both transparencies, the distortion is not usually
noticable from side to side. The distrtion is also not enough to cause a
problem with parts distance or alignment/size. Any distortion that is a
problem is fixed easily in Acrobat distiller. Like Hans said, you do not
need total blackness. The trick is to get all the traces and pads the same
color, whatever shade of black or grey that may be. If it is consistent,
then it is all a matter of your exposure distance, time and light source.
Best regards,
-Mike