>I spent 2 years looking for a cheap way to get good consistant print-outs.
>Lasers never worked for finer stuff. 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.
Russel,
I just lately experimented a lot (well, was forced to do so due to the
transition to through hole plated boards). My findings were that the
printer is really only half of the story. The exposing process AND
also the type of photoactive coating have a huge impact too. I used to
sucessfully and happyly work with regular tracing paper and a HP
LaserJet 4P. By using high quality precoated PCB base material this
worked (and still does of course) very well and I could do 8 mil
traces without problems and repeatable results. Now that I use dry
film resist that I laminate onto the pure copper plated base material
things are different. The main problem with the laser is that all the
film medias I tried (tracing paper, transparencies, different brands
of films for laser, regular paper etc) all were not black enough for
the dry film resist which is magnitudes more light sensitive than the
pre coated material I had. Since I figure that most people on this
list are not laminating dry film photoresist I think that lasers CAN
do really well. Again, the laser is just one part of the process and
if the other material /processing does not match one could get the
impression that lasers were inferior.
What is true (acording to my personal experiennce of course only) is
that there can be problems with propper alignement, but acording to my
experinece this is only then an issue if you use a CNC drilling
machine. For PCB's that are drilled manually this should not matter
cause the miss allignement is the same for both sides of the print if
the output of the artwork is placed at the same spot of the
transparency used.
So, lasers are IMHO a very good option for good quality pre coated
material which I figure is what most people use.
In order to work with the dry film photoresist I use an epson stylus
C62 which is very cheap ($80), so getting one did not hurt that much.
I did not had the time to find out why this printer is giving so much
better results that the HP DeskJet. After experimenting three days
long I was just happy to have a working setup. Eventually it boils
down to the kind of Ink the different products are using or whatever -
again, I was happy to have a really good working setup.
I also agree with the other poster that there are quality differences
among different products, but the epson stands here exclusively to
produce films and should it break in a year or so I will happyily
spend another $80 to get a replacement.
Markus