Laser Printing PCB's - Page 1
Forum section: electronics / general

author: FreeThinker
author_rank: Frequent Contributor
timestamp: June 24, 2011, 01:31:22 pm
content: I have a old Epson AL C1100 laser printer and was wondering if anyone had hacker this? What I would like to do is print directly on to sensitised board and bypass the toner transfer stage, ie print the image on the light sensitive board without depositing toner. My main problem at the moment is that the drum unit is at the end of it's life and needs replacing. You can buy a drum rest widget but you would then have the same problem with the toner carts. What I would like to do is remove the drum/toner assembly and just use the paper feed and scanner to expose the board.Is this feasible/possible? Not really thought this through yet just looking for ideas anyone done or seen anything similar?

author: david77
author_rank: Frequent Contributor
timestamp: June 24, 2011, 03:19:24 pm
content: Apart from the mechanical challenge to mod the printer so that it "eats" hard pcb's instead of soft fluffy paper, I don't think the laser will be able to develop the photo resist on the pcb.My guess is the board would come out exactly like you put it in.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: June 24, 2011, 03:37:11 pm
content: Hmmm! Did a bit of googling after I posted and the laser emits little in the way of UV (shame) Also the timing sequence is not as I thought so the scanning and paperfeeds are two separate cycles and not an expose/transfer in one cycle. Makes sense as the image is built up from 4 passes one for each colour. Even just printing black would require two passes (one to expose the drum one to transfer to paper) therefore the copper board would need to replace the drum in the cycle.Not looking good but will give it some more thought. May be the reason no one has tried it before

author: bilko
author_rank: Frequent Contributor
timestamp: June 24, 2011, 03:47:57 pm
content: Another idea, what about a flat bed plotter with a UV laser led from a DVD writer instead of the pen. Don't know what power you need for the exposure though. Plotter will take vector files whereas most laser printers use bitmap

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 24, 2011, 04:03:26 pm
content: You can't laser print on conductive surfaces like PCB copper. Laser printing works by electrostatic adhesion of the toner onto the paper.

author: Unknown
author_rank: Unknown
timestamp: June 24, 2011, 04:27:18 pm
content: Quote from: mikeselectricstuff on June 24, 2011, 04:03:26 pmI am quite certain they meant to use UV radiation to expose the photoresist coating, not print toner on a copper clad.It should be possible to expose the photoresist with a UV laser and an x-y translation stage, but I dont see the purpose with so cheap PCB services around.Anyway, a method to print on a copper clad directly is to use a wax ink printer.

author: sacherjj
author_rank: Frequent Contributor
timestamp: June 24, 2011, 04:35:06 pm
content: I think this would only be possible for toner transfer method, rather than photo resist type boards. The Laser has very little UV content, more IR.The laser prints onto the drum which causes toner to be lifted, then transferred onto the paper and then fused. Electrostatic transfer is possible if you have an active electrode contacting the copper (much like electrostatic painting or powder coating.) However, I think this would be a tough think to work out.An easy method would probably be to find an inkjet ink that will handle the etching process and use that in an inkjet which already takes thick components for CD/DVD printing.

author: Zero999
author_rank: Super Contributor
timestamp: June 24, 2011, 05:33:30 pm
content: Quote from: Alex on June 24, 2011, 04:27:18 pmYou're right that it would be a difficult and challenging project but once it's been done, you can have as many really cheap PCBs as you like. It seems like it'd be the sort of thing someone would do just because they're interested in it. I think it might be better to use moving mirrors rather than moving the laser because it will speed the whole process up.

author: Unknown
author_rank: Unknown
timestamp: June 24, 2011, 05:39:58 pm
content: Quote from: Hero999 on June 24, 2011, 05:33:30 pmYou are right, but moving the laser head might be more forgiving in terms of average DIY construction quality?

author: gregariz
author_rank: Frequent Contributor
timestamp: June 24, 2011, 06:05:05 pm
content: it not a laser but they use the CD printing feature on some inkjets to print to small boards that fit in the CD slothttp://www.fullspectrumengineering.com/pcbinkjet.html

author: TheWelly888
author_rank: Frequent Contributor
timestamp: June 24, 2011, 06:08:32 pm
content: Quote from: yachtronics on June 24, 2011, 03:47:57 pmWouldn't it be easier to fit an etch resist pen to the flat bed plotter? Or at least plot on transparent paper to make a UV mask?

author: Joshua
author_rank: Regular Contributor
timestamp: June 25, 2011, 01:53:38 pm
content: I know quite a few people have done what you are wanting to do with epson inkjet printers. Something about the epson printers allow them to mod the printer to allow it to accept copper clad boards.

author: sacherjj
author_rank: Frequent Contributor
timestamp: June 25, 2011, 02:50:47 pm
content: I have an Epson Photo 960 that still works but we have retired for a newer HP printer. Hmm.. I'm tempted to try this.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: June 25, 2011, 03:19:19 pm
content: Hi all thanks for the replys.The epson inkjet mods would indeed be the simplest way to go and using pigment ink which is polymer based and baking to harden then you can indeed make some reasonable pcb's. However my idea was to use my existing al c1100 printer to simply expose pre-sensitised board for one off boards. After some serious disassembly (as this was due for the tip it looks mechanically feasible to remove the drum unit and use the existing drum drive to feed he board across the scanner with some sort of custom carrier. The main problems are that you need to fool the printer that the drum exists, is still serviceable, a not least mod the laser to emit in the UV. First job I think is to rip out the scanner and see if it can be modded to take (say) a laser from a cd writer. Suspect that the power output would be too low to be honest but worth a look.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 25, 2011, 04:00:22 pm
content: This is a subject that's always coming up on electronics lists & forums - I don't know why so many people keep wasting time trying to come up with new ways to do homemade PCBs, when UV photoetching has worked just fine for the last few decades and is as quick and easy as you are going to get.There isn't much point in exploring possible ways to get higher density than the 8-10 mil achievable with normal photoetch methods, as once you need that sort of density, you also tend to need lots of vias, and increasing via numbers (especially under SMDs) are the tipping point in the balance between homebrew and professionally made PCBs.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: June 25, 2011, 05:16:50 pm
content: Quote from: mikeselectricstuff on June 25, 2011, 04:00:22 pmProbably very true. But it'll never stop people from trying.