, I have decided that ist probably best to get one of the tubes that AuroraB recomends. 
One tube can do the jo, but the board should not be too wide.
You have appx. 42 cm active length from on tube, which should be adequate, but in the transverse direction of the tube, one needs more tubes spaced appx 6-7 cm for even ditribution. One tube will work, but remember to compensate for exposure time, - it's proportional to distance. If you use very thin tracks, you might have problems with "underlightning", light falling in with a low angle. If possible, reverse your printout, so that the ink or toner is lying directly towards the PBC. You will have to experiment with exposure time, - but I think appx 4 min should do the trick, for an appx 10-12 cm wide board.
Here is also another norwegian source for what you need;
www.krepro.no
check in "Prototypefremstilling- kretskort"
Developing with NaOH,- the recommended concentration is 12g/liter,- normal room temp works OK. Sometimes, on old "well stored" material, a very light swabbing with a cotton wool bud is necesseary to loosen off the rest of the resist.
Oh- BTW normal "kaustisk soda" bought i a painters shop works OK, - no need for chemically pure NaOH.
Good luck!
You have appx. 42 cm active length from on tube, which should be adequate, but in the transverse direction of the tube, one needs more tubes spaced appx 6-7 cm for even ditribution. One tube will work, but remember to compensate for exposure time, - it's proportional to distance. If you use very thin tracks, you might have problems with "underlightning", light falling in with a low angle. If possible, reverse your printout, so that the ink or toner is lying directly towards the PBC. You will have to experiment with exposure time, - but I think appx 4 min should do the trick, for an appx 10-12 cm wide board.
Here is also another norwegian source for what you need;
www.krepro.no
check in "Prototypefremstilling- kretskort"
Developing with NaOH,- the recommended concentration is 12g/liter,- normal room temp works OK. Sometimes, on old "well stored" material, a very light swabbing with a cotton wool bud is necesseary to loosen off the rest of the resist.
Oh- BTW normal "kaustisk soda" bought i a painters shop works OK, - no need for chemically pure NaOH.
Good luck!
If you expose too long the etching will remove all the copper from the board, leaving nothing. I would assume that if your transparency is super, super, perfectly dark then you could expose indefinetly and get the best result. But thats a little theoretical. I've had lots of trouble overexposing.
Pete
Pete
Thanks Aurora B for the info, also the website contained usefull info.
One question (last one I hope) : Distance between board and UV tube. Let`s say 10cm above the board and the board is 7,5 cm wide.
Do you recon that is ok. After that do some test with exposure time, like kepro recomends.
NaOH I can get at the lab, where I`m taking my masters.
Tube and boards are on their way (Happy Christmas
)
Thanks again
Christoher
One question (last one I hope) : Distance between board and UV tube. Let`s say 10cm above the board and the board is 7,5 cm wide.
Do you recon that is ok. After that do some test with exposure time, like kepro recomends.
NaOH I can get at the lab, where I`m taking my masters.
Tube and boards are on their way (Happy Christmas
)Thanks again
Christoher
Since some many of the members here make theyr PCBs themselves, I'll ask a few questions 
I'm designing my first one, with Eagle.
What configuration do you use for self made PCBs? I used Eagle's default one (trace width: 16mil, space between 2 traces: 8mil)
It looked nice on the computer's screen. But when I printed it, and saw the real size, the traces are sooo thin, and the space between them is even thinner.
What size and spacing do you use?
I'm designing my first one, with Eagle.
What configuration do you use for self made PCBs? I used Eagle's default one (trace width: 16mil, space between 2 traces: 8mil)
It looked nice on the computer's screen. But when I printed it, and saw the real size, the traces are sooo thin, and the space between them is even thinner.
What size and spacing do you use?
For homemade PCbs I would use 40 mil as std, maybe 50, maybe down to 20 mil in special cases, and 30 -40 mil as normal spacing. Less-than-perfect equipment requires better spacing and wider traces, at least as long as there is room for it on the board. This reduces the chance for micro-breaks and short circuits.
The smaller widths and spacings would be reserved for traces in-between component pins.
The smaller widths and spacings would be reserved for traces in-between component pins.
Yes! Don't put your exposed PCB to long in the developper or everything will disappear. I wasted 5 Eurocard sized boards because I was using the stuff that you use to clain your plumbing etc. After 4 days of non-stop failure, I figured that it wasn't due to my exposing times, but due to the developper that my PCB's failed. So I went to the electronics store and asked them. They told me that if you put the PCB in the developper too long, the traces will vanish.Bricolo said:
Please do elaboratestokessd said:
.
I'm having the same problems in ExpressPCB. I have my PCB all layed out in software, but every time I try to export it to BMP, I just get a black rectangle. I tried changing the background color to white, and the trace color to black, but I still just got one big black rectangle the size of the PCB. Any help on this? I need to get my 300W bridged/paralleled GC going.
Cheers,
Zach
Cheers,
Zach
PCB software.....?
I use the free version of Eagle Cad. It has some limitations as a free version. I have never had any problems printing a project.
However you can`t print your project as an image file. Thats probably one of the limitations(?). What I did to convert the project into an image was to print it and then scan it.
You need also to turn off the various layers before printing(Components,Value etc.). So that what you see on your screen, are only tracks and pads.
Bricolo said:
I use the free version of Eagle Cad. It has some limitations as a free version. I have never had any problems printing a project.
However you can`t print your project as an image file. Thats probably one of the limitations(?). What I did to convert the project into an image was to print it and then scan it.
You need also to turn off the various layers before printing(Components,Value etc.). So that what you see on your screen, are only tracks and pads.
davesaudio said:
I have tried various PCB software, but have always gone back to
Eagle.
The following limitations apply to the EAGLE Light Edition in general:
The useable board area is limited to 100 x 80 mm (4 x 3.2 inches).
Only two signal layers can be used (Top and Bottom).
The schematic editor can only create one sheet.
(From Eagle webpage)
http://www.cadsoft.de/freeware.htm
So you can pack alot of parts on your board, no pin limitations
as I stated earlier, I am now a disgruntled Ultiboard user -- problems with Win2K and the product which they refuse to fix.davesaudio said:
Ergo hoc -- I have learned eagle -- and it is much easier in some respects (not having to name nets for one thing.) I would suggest downloading it and printing out the manuals.
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