[yasoosay]

ANY ONE KNOWING HANK E-MAIL

[happytriger2000]

PCB printer S22/T22:

RhinoFabLab

[satanicoo]

Hey guys,
So, can this mod be performed on a laser printer?
From what i have read, the toner does not "glue" to the copper:

"You can't laser print on conductive surfaces like PCB copper. Laser printing works by electrostatic adhesion of the toner onto the paper. "

Is this true? i was about to try this mod on a HP laserJet 1010 and a Samsung ML-1610 :8

[epineh]

I have heard somewhere that somebody got a laser to work, but the mod is a completely different one to using an inkjet, it would be nice though...you may have to try some serious googling

Cheers.

Russell.

[greybeard]

Hi satanicoo,
Laser printers start by covering the drum, which is a semiconductor, with a uniform electrostatic charge.
The drum is photosensitive, so that when an image is projected onto it, the exposed areas lose the charge.
The toner drops onto the drum and "sticks" to the remaining charged areas.
As the paper, which is effectively an insulator, rolls into contact with the drum, it passes over a wire carrying the opposite charge, which effectively "pulls" the toner onto the paper, because the wire, having a much smaller radius, has a much higher charge density.
Passing over a heated roller, the toner melts onto the paper.

A sheet of copper(your pcb) could be given a charge to attract the toner from the drum, but the uniform charge across its surface will spread the toner out and destroy the pattern your trying to produce.

IMHO you're going to need to tranfer the toner from the paper onto the pcb by removing the heater roller stage first, possibly by pressing the heated pcb against the paper instead.

I wonder if you could stick the paper and pcb together, then remove the paper(soak it off) then etch ?

Good Luck,
John

[H500]

Toner transfer work so well already, for double sided boards. I don't know if anything would be gained with direct transfer. I wouldn't want to risk scratching the drum.

[satanicoo]

Toner transfer work so well already, for double sided boards. I don't know if anything would be gained with direct transfer. I wouldn't want to risk scratching the drum.

These are abandoned printers, mostly stopped at a corner, that's why i was about to dismantle them and reconvert them to pcb printing. But hey, i'll stick to toner transfer!

[probinson]

It seems like the image would blur but Laser printers print just fine on copper and work infinitely better than an Inkjet. The problem is Laser printers require tighter tolerances. Consequently, they are much better made than Inkjets which makes changing the paper feed considerably more difficult.

The other problem is the drum being easily scratched and light sensitive. The light sensitivity problem is more than just shading the drum while printing. Exposure to bright light, especially sunlight, will permanently affect the coating and lower the contrast.

Pete

[greybeard]

It seems like the image would blur but Laser printers print just fine on copper ......
Pete

Hi Pete,
I'm surprised, but would like to see it happening
Do you have any link to a video of it running ?

Regards
John

[probinson]

Somewhere in the forum I have posted about a LaserJet flatbed conversion I did years ago. The drum printed at the front instead of the bottom on that model so the tray was 30 degrees from vertical. It had to hang off the edge of the table but worked fine and was muck easier to mod than the LaserJet III or LaserJet 5.

I recommend the LaserJet 5 if your doing a flatbed mod, however. The 5 is a simplified update of the LaserJet III and makes an excellent flatbed.

Pete

P.S. My old Epson (I forget which model) used a belt instead of a drum. That would be so much easier and ideal for a flatbed conversion.

Theoretically, color Lasers should also be excellent candidates because they use a transfer belt or drum so all of the sensitive components would remain enclosed and only the transfer mechanism needs to be exposed.

[probinson]

Hi Pete,
I'm surprised, but would like to see it happening
Do you have any link to a video of it running ?

Regards
John

Just tape a the leading edge of piece of aluminum foil to a sheet of paper and run it through the Laser printer to see how well it prints on metal. (But don't use teflon coated foil.)

[greybeard]

It seems like the image would blur but Laser printers print just fine on copper and work infinitely better than an Inkjet. The problem is Laser printers require tighter tolerances. Consequently, they are much better made than Inkjets which makes changing the paper feed considerably more difficult.

The other problem is the drum being easily scratched and light sensitive. The light sensitivity problem is more than just shading the drum while printing. Exposure to bright light, especially sunlight, will permanently affect the coating and lower the contrast.

Pete

Hi Pete,
While I'd agree that the effect of toner as a resist is infinitely better than dried ink, I'm not sure I'd go so far as to say the system is infinitely better.

In your #405 you mentioned the pinholing that the toner produced, and that, plus the other mechanical difficulties you mentioned, would be reason enough for you, in your #450, to conclude that inkjets were the preferred option.

Just caught your latest post re ally foil. Unfortunately I don't have a working laser, so I wonder if anyone that does would care to demo it ?

My own preference regarding inkjets would be to investigate the Ricoh gel printers, as the ink is totally waterproof(I've proved that for myself) but other projects are intervening and time is getting in short supply

Regards
John

[probinson]

Good point John. 10 years ago, when I was modding printers, laser printed resist was infinitely better (pinholes in large areas make the board less attractive but don't have any affect on function). Now that there are inks that stand up to 10 minutes in a hot bath I would have to amend my position for the purpose of an etch resist.

I use CNC or a professional service for my PCB needs now. The only parts I print now are the panels for my equipment and InkJet just doesn't cut it. The print is sandwiched between the metal panel and a plastic covering. The Laser printed images work the best and remain razor sharp during the lamination process. I also use a Phasor (solid Crayon type ink) when I need a transparent color, like the filter for an LED display. It blurs slightly during lamination so I can't go much smaller than 6 point text but it's much better than InkJet.

The color Lasers (Monolta and HP) and the Xerox Phasor are not modified, by the way. A printer that handles card stock is all I need now days. I print a mirror image on the back of the clear plastic cover sheet, laminate that to the metal panel, then Laser cut the openings. You end up with a panel so tough that you can clean it with lacquer thinner.

Pete

[satanicoo]

Nice idea, nothing like testing on a sheet of copper!

[greybeard]

.......... I print a mirror image on the back of the clear plastic cover sheet, laminate that to the metal panel, then Laser cut the openings. You end up with a panel so tough that you can clean it with lacquer thinner.

Pete

Respect, Pete, that is a very neat, minimalist solution.
Regards
John

[mmcp42]

hmm
how about a wax phase change printer?

hee hee me too slow typing!

[probinson]

hmm
how about a wax phase change printer?

My Xerox Phasor uses a wax (like a Crayon), which is why it bleeds a little during lamination. You can see in one of the devices I build that the text isn't super crisp like you get from a laser printer but that green lens over the LEDs is printed on there.

Pete

[epineh]

Sorry for digging up an old thread, but I was wondering if anybody is still using this method to make PCB's?

Personally I live in a very hot humid climate, we basically have two seasons - hot and hot/raining...as a result heavily modified printers living in the shed experience very short print head life. I have gone through two printers previously (both brand new) and don't have the strength or time to go through the process again. Although having said that I do miss being able to print out designs easily, and don't really wish to change to toner or UV cure resist, but may have to concede defeat. I also wish to make double sided boards and that is one thing I could never get to work with direct printing, unless I printed onto half thickness board and epoxied them together, which I did a couple of times with very good results.

If I was to suggest a progression it would be to bolt a print head onto a reasonably fast CNC Machine, magically do all the software to make it work and enjoy perfectly aligned prints all day every day, sounds simple enough.

Thinking out loud I also built myself a 3d printer, and sometimes wonder how well PLA would work as a resist, it would be dead simple to print a single layer of plastic onto copper with that...hmmm, might be time to do some experimenting...

[greybeard]

Hi Old Buddy,
I was thinking of contacting you on the very same subject earlier this week, but been dashing about, and didn't get round to it.
It's midnight here, and I'm just back from a 200 mile trip, so I'll pm over the weekend with news etc.
Regards
John

[greybeard]

Screen printers, amongst others, use a uv cured resist. It is quite viscous, but might be an alternative route if you were considering the 3d printer approach.
Perhaps there's a uv curable gel that could be extruded ?
John