Toner transfer with a twist -- anyone tried this?

rif

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2003-01-27 2:36 am
South NJ
Let me preface this -- I haven't tried this, it's just a thought that came to me.

Why not disable/bypass the fuser portion of the laser printer when printing?

Seems to me that the fuser is doing a toner transfer of a kind -- just melting the plastic on to paper. So if one could carefully remove the paper before fusing, wouldn't the ironing onto a PCB be more efficient -- one melting instead of two?

The Basics: Static Electricity - How Laser Printers Work | HowStuffWorks
 

rif

Member
Paid Member
2003-01-27 2:36 am
South NJ
thomas997 said:
Plus how would you do this without taking the whole machine apart.
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Well this is a diy hobby... :D ;) And laser printers are pretty cheap nowadays.

If your going to do that, maybe you could just modify it to print straight onto a PCB :) [/B]
That would be best, of course, but I see 2 issues: 1) PCBs aren't flexible. But with a little creativitiy, I'm sure someone could get by that. 2) The printing relies on electrostatic attraction -- with a metal (copper on PCB), the charge would redistribute itself freely and you'd lose the image.
 
As long as you're thinking about using printers for your PCB patterns, go get yourself a REAL LASER printer... It's been out for a while, but earlier this year IIRC Wired Magazine did a short blurb on it and reminded me...

Feed it a standard printer signal, and it makes it happen on ANYTHING from copper-clad PCB material, to wood, aluminium, plastics, whatever.

I would NOT however reccommend taking THAT puppy apart!

:D
 
It's just not going to work.

You'd be getting toner all over the place, especially inside the printer.

The idea I've been thinking about for a while is this: directly printing on the copper... After all, PCBs are just copper sheets glued to epoxy. If we could print on the copper sheet first, then cut it to dimension and glue it to bare epoxy, that would be a huge step forward. I don't think 35 µm copper sheets would be a problem in a regular laser printer? The thing I'm not sure about, is how to glue them on epoxy. Not sure what kind of glue is used, if they glue the copper sheets under some pressure/some temperature, etc. That would be the harder part... unless someone tells me that reliably gluing copper sheets on epoxy is very simple...

Edit: I've seen someone has already told about the problems of printing directly on copper. I think he's probably right, but that would be interesting to give it a shot...
 
there aren't many things worse in a workshop than carbon black -- it smudges everything AND conducts electricity.

you can use a plotter to apply waterproof ink directly from pen to copper -- here's the problem -- most of the plotters are programmed in HP/GL (Hewlett Packard Graphics Language) -- you have to get the gerber file and then manipulate it -- great if you remember DOS and how to use a text editor.

i have done this with small boards -- only a few square inches -- it works. with larger boards the inertia of the PCB is such that it is difficult to maintain registration -- at least on the plotter which I used.
 
Ok... well, all in all, I think that toner transfer isn't so bad. ;-)

I highly recommend Pulsar products (TTS...). Very easy to work with. The thing is to find the right amount of temperature and pressure; I was used to glossy photo paper, and TTS is much thinner, so you have to set your iron to a much lower temp and apply it for only a few seconds (whereas I ironed for like 2 minutes with photo paper). If temperature is too high, the finer toner tracks will get kind of fuzzy.

I don't think that it would be worth the trouble to hack a laser printer and all, unless you made boards in high quantity - but then again, if you did that, you would probably not make them yourself...

On the idea of directly printing on copper - if that's a problem with laser printers because of electrostatic diffusion, I guess we could use an inkjet printer instead, and print on copper sheets. Then we would need resistant ink, but I think I remember that some company actually makes inkjet inks for that purpose... or maybe it was some hack to put some special ink in regular, used cartridges...
 

rif

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2003-01-27 2:36 am
South NJ
jackinnj said:
there aren't many things worse in a workshop than carbon black -- it smudges everything AND conducts electricity.

you can use a plotter to apply waterproof ink directly from pen to copper -- here's the problem -- most of the plotters are programmed in HP/GL (Hewlett Packard Graphics Language) -- you have to get the gerber file and then manipulate it -- great if you remember DOS and how to use a text editor.

i have done this with small boards -- only a few square inches -- it works. with larger boards the inertia of the PCB is such that it is difficult to maintain registration -- at least on the plotter which I used.


Ah -- but how about hacking an inkjet and turning it into something else? A normal inkjet's "axes" are left/right -- the printer head moves back and forth, and feeding the paper around a roller. What if we got rid of the roller, and rigged something to step the PCB or the print head? It's not a plotter since it still only moves one of the axes in one direction -- just changing the mechanics of the axis. It has the benefit of using modern, standard unmodified drivers
 
plotting pcb's

I used a plotter for plotting pcb's. I even made a web page for it some time ago here

Disadvantages are: sometimes the etched pcb came out with jagged edges, when covering larger area's the ink would sometimes etch away a little but that was probably due to the etch-resist pen i used.

All in all a not very satisfactory system. I switched to laser-toner-transfer but that gave more problems due to paper choice. And the jagged edges remained.

The accompanying foto shows the faults in larger ink-area's (pcb backlit with a lamp)
 

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yep, i made it myself.

Audiowizard: all the light spots in the black (copper) bands are etched away right down to the epoxy, around those spots the copper is pretty thin so I discarded them.

On using inkjet printers for "printing" pcbs.: there are inkjet cartridges that contain a sort of wax-based ink. They're used for those iron-on t-shirt prints. The ink dries pretty fast. Maye that would work?
 
A quality film is the key in successfully and easily etching good PCBs at home. Once You have a good film the rest is a breeze.

I think I messed with everything what concerns making DIY films for PCB exposure (I started making films by gluing those black tape stripes on clear foil :dead: ).

After all I came to the conclusion that ALL of the DIY methods are unsatisfying for high qualtiy results and there is no way around getting films made on a professional film exposure machine that usually works with PostScript files (I don`t know what is the correct notation in English for that kind of machine. In German it`s called "Satzbelichtungsmaschine").

Anyway, ask at Your local print shop, they probably have such a thing or at least they might know where to go. Prices are reasonable, I pay around 1 Euro per 10x10cm highest quality film - black areas absolutely leakproof against light, finest resolution (usually 2400dpi) with razorsharp outlines.
I think that is really worth it.
 
yep, i made it myself.

Audiowizard: all the light spots in the black (copper) bands are etched away right down to the epoxy, around those spots the copper is pretty thin so I discarded them.

On using inkjet printers for "printing" pcbs.: there are inkjet cartridges that contain a sort of wax-based ink. They're used for those iron-on t-shirt prints. The ink dries pretty fast. Maye that would work?

I know some roland printers also are capable of cutting film used for heat transfer used in t shirt printing that replace the print head with a cutter and film...