PCB making with printer

[Dwiel]

Hello. I decided that I would attempt using my printer to put a pattern on a coper plate for making a PCB board. I was following the instructions posted at: http://www.fullnet.com/u/tomg/gooteepc.htm. I even got the exact paper recomended for use with this process. I printed out my design and tried to iron it onto my board. The ink wouldnt come off and the paper didnt even stick to the copper. I must be doing something wrong because Im not even getting the paper to stick....

I was able to makea very simple layout by simply usinga CD marker pen to draw the circuit that I could kinda see on my board after ironing. I had to tilt the board at the right angle to even see the pattern. There was no ink, more of a less shiny area.

I was able to etch the board and now have my first simple circuit, but I would really like to be able to use my printer instead my hand and a pen, as there is no way I will be able to draw a circuit board for SSOP chips that I plan on using.

If anyone has any ideas on why what I did didnt work at all, I'd love to hear them

Thanks a bunch!!

[Dwiel]

Damn... It looks like I dont have a laser printer. Doh. I have a InkJet. I assume that this is the problem.

If this is the case, is it OK, if I do the printer over at school and bring home the paper? There will be around a 30min lag time between printing and ironing. Wil this be OK, or does it need to be transfered ASAP?

Thanks abunch!

[tsmith1315]

There will be around a 30min lag time between printing and ironing. Wil this be OK, or does it need to be transfered ASAP?

Shouldn't be a problem. The way I understand it, laser toner is actually a plastic (leaving myself open to flames here). Heat softens the toner, which sticks to the board when you carefully peel the paper off.

Just remember the print will be reversed when transferred. That's the kind of silly thing I tend to overlook...

Tim

[Dwiel]

Cool, thats good news. I dont have a laser printer, so the only way I can do one of these is by buming the prints of of my university ;P

Thanks for the help!

[jackinnj]

Originally posted by tsmith1315


Just remember the print will be reversed when transferred. That's the kind of silly thing I tend to overlook...

Tim

your PCB program should allow you to print a "reflection" --

I used a Hewlett Packard 7470A plotter to print directly onto the copper -- it doesn't work well with a big board because of the intertia. It will work OK with a small board, say 2" x 2".

You take the Gerber code as an HP GL (Graphics Language) file, save it to disk, then transmit to the plotter via RS232. -- here's some info on HPGL: http://www.tech-diy.com/HP%20Graphics%20Language.htm

There are things which you can do to make the plotting go pretty fast --

[Dwiel]

I really dont have a plotter available to me. I do have a laser printer which I can print to and then use the printed paper within about 30/45 mins... I dont mind the mirroring though and can easily take it into account. Is it OK that I will not be able to iron the print right away? What about 24 hrs between printing and ironing? Does it really matter?

Thanks!

[jackinnj]

well, you want the paper pretty loaded up with toner -- to bad you can't get the fuser disabled (although you would have toner all over the place. Some folks have success running the paper through twice -- my HP2100 doesn't align close enough to do this.

I had read somewhere that using photo-paper for inkjets in your laser printer would "release" the toner more readily than regular bond paper. Why not ask at the Yahoo group dedicated to PCB's.
http://groups.yahoo.com/group/Homebrew_PCBs/messages

The investment in a little light-box and a photo safety lamp will allow you to make photo-lith PCB's -- I do these all the time and have no problem with 10 mil traces. You can correct the "positive" if you have too, with a red or black marker.

[sam9]

Iron-on pcb patterns is a funny business. Some people have very good reliable results. Some, like myself have terrible results. There are a number of vaiables: choice of toner, choice of paper, cleanliness of copper, choice of iron, temperature of iron. I have made a couple of good PCBs with the process, but the results were not consistent and not repeatable. One factor in particular seems to be the iron - old fashioned "dumb" irons seem to work better than modern "smart irons". If you can get all these things under control and do it e*x*a*c*t*l*y the same way each time it should be workable.



Anyway, I found the UV photo transfer very reliable. The chemical mess is easier to manage than the actual etching so I don't consider it a significant drawback.

[acenovelty]

Go here:

http://www.techniks.com/
for Press-n-Blue materials. This stuff actually works. Built many boards with it. You need a laser printer to print directly from your PC or a laser copier from hard copy.

Prosit

[Dwiel]

I got ahold of a laser printer and tried to make a couple SOIC -> DIP and SSOP -> DIP boards to see how small I could make things.

Here are the results:



It really wasnt that bad. The hardest part was the SSOP in the top left corner which didnt turn out well at all. I'm not quite sure why this happened, but I think it might be because I didnt get all of the peper off of the board before etching it. I thought that the etchent (Ferric Chloride) would remove the paper on its own, but it didnt. THe reason why I left some of the paper on was because some of the ink was coming off. I might just not have ironed for long enough... Who knows.

Anyway, 3 of the 4 circuits came out useable, so I consider it a sucess.

Next time, I am going to try to design it so that there is more toner in all of the spots which dont have any components. This will save money by requiring less etchent and seems like a decent idea... For those of you who know, is this an OK stradegy? Nothing gonna go bad if I do it this way?

Thanks for all of the help!