AOUT pcb printing problem

[wicked1]

HI, I asked this once before, and the problem is better, but still not working.

The traces on the aout PCB are so close together that they run into each other when I print it.  I was told to increase the resolution of my printer, so I have put it to it's max, which is only 300dpi.  It's a laserjet 4l, which is what people on many many electronics forums and mailing lists have recommended. (something about older laser printers putting down more toner for better transfers).

so, I export from Eagle at 300dpi and put into photoshop to invert and do any final cleanup, then print at 300dpi

So, does EVERYONE in the midibox community have a newer printer for printing PCB's or am I still missing something else?

Basically, the bottom section of the board, the pads are running into the traces next to them or below them.

I've photoshopped it as much as I can to try to make the traces smaller, or move pads a little when possible.  I worked on it for an hour last night, and while it now prints ok (barely) I really doubt the traces will still be separate once I iron it to the copper clad, and the traces spread a little from the heat.

I can't be the only one with this problem, unless I am missing something. 

I print PCB's all the time for my modular synth, and this is the first time I've run into this problem (which is why I say I can't be the only one w/ this issue)

Thanks for any help

Also, feel free to move this topic if it fits somewhere else.  I couldn't really find a good forum to post a question about the aout.

[DavidBanner]

try using an inkjet - i've had great results...

And if you don't have one, you must have a friend/relative/neighbor with one who'll print you off a sheet.

and if you really get stuck p/m me and i'll print one off and send it to you

[wicked1]

Im using toner transfer, and not photo transfer.  Correct me if I'm wrong, but for this method, I think I have to use a laser printer.

If I have no other choice, I suppose I could get a photo transfer setup.. but then it might be cheaper to just get a pre made pcb shipped from europe.

[DavidBanner]

I've seen ways of doing the transfer method using Inkjets too - BUT I've not used it yet (I'm using up my stock of photoboard) myself.

Is the artwork okay once printed and then smudges as you iron on?

[wicked1]

No, actually, I haven't tried to iron this layout onto copper yet.  I will try to get to it later today. 

But, when printing  the default PCB, the traces and pads did touch, just on the printout.  I edited it a little so that there is a small gap when I print it, but it is VERY close.  In the past, I've had traces spread when I heat them to do the transfer.  Maybe I'm just using too hot an iron or too much pressure or something.  I'll work with it.  My only issue w/ trial and error is that I need to print an entire page of PCB's at once, or Im wasting a bunch of that blue toner transfer paper.  (I haven't tried using standard transparency paper yet..  maybe I should try that too)

I was just surprised that I didn't find more topics about the same issue, as this printer was recommended for toner transfer.  I was hoping a bunch of people would say "yeah I had the same thing happen and this is how I fixed it" but I guess Im the only one doing it this way w/ a 300dpi printer.

[Digineural]

If you really want good traces its best to go with a 600dpi minimum.  Anything less will compromise the integrity of the board design.  Even in my experience with 600dpi there are times I wish I had better resolution.  When the traces melt together I usually score the traces/pads with a hobby knife.  If you can, expand your design or try using jumpers to get to tight spots.  Its not a preference but thats just the way it is sometimes. 

I also bought a Brother HL-2040 just for PCB printing which isn't the best in terms of toner density but does its job and for $90US, I can't complain.

Good luck

[DavidBanner]

i'm fairly sure you know all this already but i forgot to point out that's all dpi related and inkjets can do 1200dpi upwards.

[wicked1]

I know.. I just have to figure out how the inkjet toner transfer works.  Inkjets are just water soluble ink.  Laserjets are sort of plastic that gets melted to the paper.. which is why you can re-melt it and have it stick to the copper.

[nebula]

The toner transfer method is quick and easy, but not the most accurate.  Still it's very inexpensive and it's how I make boards as well.

Suggestions:

* After you iron the toner onto your board, and maybe while it's still a little warm, use a hobby knife (x-acto knife) and a metal ruler.  if you have traces that are very close together that have spread to a point where they are touching, carefully trim the toner off the board using the ruler as a guide to make sure you don't inadvertently cut into your trace.  remember, "very little" space between the traces is good enough.

* If there are spots where the toner did not transfer to the board, or where you may have inadvertently trimmed it off, just use a fine-tip permanent marker (like a "Sharpie") to dab lots of ink where you want toner to be.  When the ink dries (after about 30 seconds), dab it again.  Repeat and repeat.

* After etching, it's always easier to remove copper that was supposed to get etched than it is to make up for traces that got etched away.  So if you really can't get in there, let your tracks run together, and use your x-acto / metal ruler when done.  The copper is stuck to the board using an adhesive that can be very powerful.  If you're having trouble lifting a tiny sliver of copper off the board (i.e., between to adjacent traces), try just scoring the copper along the edges of the sliver you want to remove.  Then use a fine tip on a soldering iron with lots of heat, and slowly rub off the little slice.  This works because the adhesive is no match for a lot of heat.  Be careful not to rub off copper that you want.

These are brute-force methods for home PCB manufacture on the cheap.  If you're doing toner transfer, you're obviously not in this to win any aesthetic awards for your board.  So make it work, make it reliable, and don't enter it into any fashion shows.

[nebula]

I know.. I just have to figure out how the inkjet toner transfer works.  Inkjets are just water soluble ink.  Laserjets are sort of plastic that gets melted to the paper.. which is why you can re-melt it and have it stick to the copper.

I'm not going to tell you that the way i do it is how you should do it, but I'll share my method anyway, and you can try if you like:

I print my toner onto the shiny paper used as the backing for a sheet of mailing labels.  The toner comes off this type of paper very easily.

To make it work any better, consider NOT "re-melting" the toner.  The last stage your sheet goes through as it comes from your laser printer is the "fuser".  If, in the middle of printing, you lift the laser printer's cover, it will stop, abruptly, and not resume.  You now have to go into the printer and remove the sheet manually.

The toner should have already transferred to the paper, but it should not have gone through the final heat stage yet.  Try carefully removing the sheet at this point.  (Depending on the printer you're using, you may or may not be successful with this).  The toner will be stuck to the page, but not "fused" yet.  If you shake the page or rub it, you'll smudge the powdered toner.  But a little careful manipulation, placing the copper-clad board squarely on the  area with the toner, then heating, will transfer the toner beautifully.  No pinholes, no cracks...

... this took me a long time to get good at, but I prefer the results.  (YMMV)

Cheers

[lief138]

I print my toner onto the shiny paper used as the backing for a sheet of mailing labels.  The toner comes off this type of paper very easily.

butting in further, really any shiney paper works well. The pages of fashion/porn mags work great

Lief138

[wicked1]

Thanks a lot!  those are great ideas.  I don't know why I didn't think to simply 'edit' the copper clad after I iron it on, rather than editing it in photoshop first!

This printer is dedicated to printing PCB's so I could probably open it up and unplug the fuser.

thanks for the ideas on the inexpensive (or free) transfer paper.

[stryd_one]

Hey neb, you ever considered just disconnecting power to the fuser?

[nebula]

Hey Stryd,

Never thought of that. It's a good idea.  I would try that if I hadn't already mastered the art of "printus interruptus" with my ancient Apple Personal LaserWriter.

Cheers

[Altitude]

Your problem is that your using photoshop.  You NEVER want to rasterize the traces, you always want to leave it as vector art and then it will print perfectly.  Try printing it directly from eagle and it will work perfectly

[wicked1]

The problem there is that I need to print an entire 8.5x11 inch sheet at a time.  I use press-n-peel blue paper, which isn't cheap, so I do PCB's in batches.

I did print a test from eagle, and the traces still touch.  It is better, but one of the traces is still touching.  We talked about this in chat for a while.  I think I need to find different drivers for my printer, and work with the settings a little.

I got the aout PCB working by editing the traces in photoshop.  I'll figure out whats up w/ my printer next time I print a board w/ close traces.

[stryd_one]

work with the settings a little.

Did you try the toner density setting I mentioned?

[wicked1]

not yet.  Work got really busy and put my hobby on hold. 

I've got one din, one dout, one bankstickx8 completed, and the aout partially stuffed.

I'll try messing w/ density and other drivers in the next batch.  I need to print up more din and dout pcb's.

Oh, my verowire finally made it here, too, so I have no excuse not to start on the front panel soon.  That part scares me.. I just sit and stare at the parts for it :)  I've done more complex panels, but it's always been panel mount.  Im sure it will go together easily once I just jump in and start soldering.

[e-toy]

Hey neb, you ever considered just disconnecting power to the fuser?

Most printers wont work if you only disconnect the fuser power. There's an thermal sensor wich controls the heat and if the heat dont come, the printer will report an error. If you can hack the sensor control, it will work.

[Davo]

You don't need to use up an entire sheet of transfer paper.  First print the pattern on plain paper.  Then cut out a piece of transfer paper just large enough for your pattern.  Tape that piece over the pattern you printed on the plain paper.  Finally, print again on that and you have your trace pattern on the transfer paper.

You can find reviews on different papers and various techniques at the Homebrew PCB list at http://groups.yahoo.com/group/Homebrew_PCBs/.  For example, certain brands of inkjet photo paper are good for toner-transfer.