PCB etching not going so well

jamiefbolton · August 13, 2011, 01:13:00 PM

I'm 0 for 4. I've printed a reverse image on magazine paper. Ironed for 5 minutes. Soaked in water. But the transfer isn't taking too well. Each transfer get about 80% there, but it looks nothing like some of the pictures I've seen here. Any tips that could help me. I've read everything I could find, but it's just not working as it should.

Thanks,
Jamie

Kearns892 · August 13, 2011, 02:06:36 PM

Jamie, the problem with toner transfer onto enclosures and PCBs is that there are many variables that greatly effect the quality of a transfer.

A few of these are choice of paper and toner, iron settings (as well as specific iron used), exposure time, etc.

The reading you have done is good and will help you, but you can't take someone else's method with a different set up and use it verbatim.

When I first started making my own PCBs I got similar results. What I ended up doing was a lot of experimentation with my setup changing one or a few variables at a time and recording my results. I have developed my own PCB etching "method" that gives me consistent 100% transfers this way. I use dollar tree brand photo paper and I also found that lower ironing times (~2 minutes) gave me best results (My experiments with transparency film had best results in ~40 seconds

) Even though I know other people use magazine paper and/ or longer exposure times, with my setup I couldn't replicate the results.

Recently, I have restarted this process with toner transfer on enclosures (I posted about it a week ago), and have found the different characteristics of the enclosure significantly change things. Still I was able to get a good result after about 8 tries and progressively honed in on a process that got me good results, but still needs refining.

All this to say, I can tell you what I do and it may help guide you, but only if you are willing to experiment and find your own way. It's a very zen like experience

.

Maybe post some pictures or give more detail about what you are using in your setup and we could give more concrete results of what to try.

rockhorst · August 13, 2011, 02:33:10 PM

Ironing involves some guess work. I've had good results with using a laminating machine. Firmly press the print and pcb together (maybe sandwich it) and feed it to the machine. Flip it 90 degrees and repeat it a few times. Different directions!

jamiefbolton · August 13, 2011, 02:50:49 PM

Quote from: Kearns892 on August 13, 2011, 02:06:36 PM
Jamie, the problem with toner transfer onto enclosures and PCBs is that there are many variables that greatly effect the quality of a transfer.

A few of these are choice of paper and toner, iron settings (as well as specific iron used), exposure time, etc.

The reading you have done is good and will help you, but you can't take someone else's method with a different set up and use it verbatim.

When I first started making my own PCBs I got similar results. What I ended up doing was a lot of experimentation with my setup changing one or a few variables at a time and recording my results. I have developed my own PCB etching "method" that gives me consistent 100% transfers this way. I use dollar tree brand photo paper and I also found that lower ironing times (~2 minutes) gave me best results (My experiments with transparency film had best results in ~40 seconds ) Even though I know other people use magazine paper and/ or longer exposure times, with my setup I couldn't replicate the results.

Recently, I have restarted this process with toner transfer on enclosures (I posted about it a week ago), and have found the different characteristics of the enclosure significantly change things. Still I was able to get a good result after about 8 tries and progressively honed in on a process that got me good results, but still needs refining.

All this to say, I can tell you what I do and it may help guide you, but only if you are willing to experiment and find your own way. It's a very zen like experience .

Maybe post some pictures or give more detail about what you are using in your setup and we could give more concrete results of what to try.

Good things to know. I'll go get some photo paper and try that. it might just be that the magazine i have isn't quite suitable. Thanks for the help

iccaros · August 13, 2011, 04:24:43 PM

Questions

What type of toner.. I have found that some brands will not work (see Brother)

I like the backing to sticky labels.. IT works for me, as well as press N Peal did..

makaze808 · August 13, 2011, 04:30:04 PM

I found that making the boards slightly larger and sanding all the edges round (so the board has a very small border of what ever colour your clad board is) made a big difference.

Wire wool the copper, wash, dry, keep fingers off the copper clad, and ALSO keep them off the transfer paper. I use all sorts of magazine paper, as long as it's thin, got a glossy sheen they work.

I also use the iron from hot, for 4 minutes, attention to the edges, up and down,diagonal, small circles, pressing, etc.

I plunge the board into ice water, then after 30 secs into lovely hot soapy water. \leave for a few minutes then take some 0000 grade wire wool and gently start scrubbing the paper, there is a film on that side which if you get it off will leave the bare paper exposed to the water, you sort of peel the coating off with thumb pressure and movement once the wirewool has broken through tha tfilm layer. Put it back in the soapy water and let soak for 5 mins, and it gets much easier to ease off the exposed paper with the thumb.

Sounds long winded but following the above got me from 50% to 99% success.

Warren.

makaze808 · August 13, 2011, 04:32:53 PM

Quote from: iccaros on August 13, 2011, 04:24:43 PM
Questions

What type of toner.. I have found that some brands will not work (see Brother)

I like the backing to sticky labels.. IT works for me, as well as press N Peal did..

I use a cheap brother laser printer from tesco's (UK) and it hasn't let me down yet.

If you are in the UK Staples do cheap blank magazine paper, makes it easier to transfer, but I'm a cheap skate so I still use my netto, aldi flyers.

CodeMonk · August 13, 2011, 04:51:20 PM

Quote from: rockhorst on August 13, 2011, 02:33:10 PM
Ironing involves some guess work. I've had good results with using a laminating machine. Firmly press the print and pcb together (maybe sandwich it) and feed it to the machine. Flip it 90 degrees and repeat it a few times. Different directions!

I've been wanting to get one of these, but the one option I'm not sure of is is the maximum Mil thickness to get. Concerned about the smaller Mil ones putting to much pressure on the board.
Suggestions?

jamiefbolton · August 15, 2011, 05:14:41 PM

here is what happened today. (never mind the shotty board cut. this is only practice)

I can cut a new board if you think i need to. its a samsung laser printer.

defaced · August 15, 2011, 05:46:53 PM

Along with that pic, can you post up some parameters for what you're using? Like, which kind of iron, what setting, how long did you iron, what kind of paper, what you used to clean the board prior to doing the ironing and so on? Maybe someone can spot something to help you.

Kearns892 · August 15, 2011, 06:00:49 PM

How long are you heating? In my experience, if you are under-heating the edges will be flaky, but here it looks like you ran into a problem with the center (the part that typically gets "worked" the most) and it looks like a few of the pads have been disfigured. I would suggest trying less time with the iron.

jamiefbolton · August 15, 2011, 06:47:47 PM

thanks guys for the help. here is the process.

print onto paper from Rolling Stone Magazine.
cut board.
buff board with green scotch pad.
clean with acetone.
avoid the face of the board with my hands.
iron on highest. TFal iron. using no steam.
press firmly for 3 min. (i've tried many time periods up to 5 min constant pressure)
lighter pressure moving slowly for 2 min.
let board cool. 5-10 min.
place board in cold water for 5 min.

Kearns892 · August 15, 2011, 06:53:07 PM

Have you tried anything along the lines of the 1 minute firm pressure followed by 1 minute or less of rubbing?

.Mike · August 15, 2011, 07:10:36 PM

I was finishing off the design of an enclosure this past weekend. I made an observation that might be in play here.

My new Samsung printer doesn't like being connected to the USB port on my router. When I print, the printer freezes up. I then have to go turn it off, turn it on again, and then it prints just fine. The reason I mention this is because the bottom right corner of your board-- where the toner appears to be flaking-- looks very similar to how one of my prints came out. Oddly enough, it was the only bad print, and I know exactly what caused it. On this particular print, my printer-- in a miraculous moment-- printed on the first try. I looked at the toner, and sure enough, it was flaking off in a sheet. My next few prints had remnants of my design on them.

Obviously, what happened is that the fuser in the printer was not fully heated up. The toner partially stuck to the paper, but some of it remained stuck to the fuser. The toner that did stick the the paper was either powdery, or flaking off just like in the photo.

So, long story short: use more heat. If the board is capable of accepting toner-- no oil, no fingerprints, flat, and with a slight texture-- then the only thing preventing the toner from sticking is a lack of heat.

Mike

deadastronaut · August 15, 2011, 07:35:18 PM

i tape my pcb toner images to the pcb to stop it moving/sliding...

place pcb on table, take masking tape and stick to the middle back of your image, use this to line up the image on the copper board, then stick overhanging tape to the table...tight so it cant move..

use more tape to do the sides...(not overlapping the other tape..you now have a flat and firm pcb and image...

place a blank piece of paper over it all and iron...copper clad gets very hot very quick...you may be over doing it a bit....(your iron may be too hot..try cotton setting instead of linen)
hold the iron flat on the paper/pcb for a while, (20-30seconds)...then use the tip of the iron back and forth, criss cross as well, give a few finaL sweeps over it all...

i then peel it off tape n all,while hot as f... and put it straight into running cold water.(i never let it cool)..leave a while till you see the image coming through...peel off tape under running water....

rub off excess paper, use a toothbrush if you have fibres left on it....done... well thats how i do it....as long as its all CLEAN you should be ok.........
but like others have said, there are variables...printer/heat etc....good luck...

jamiefbolton · August 15, 2011, 08:18:55 PM

thanks guys for the tips and variables. i got a much better transfer this past time, but the paper slid causing the image to skew. i'll try the masking tape next.

jamiefbolton · August 17, 2011, 06:46:14 PM

ok guys. i finally got a crisp transfer using the photo paper. but something has happened when it dries, the print turns a pasty grey when it dries. it doesn't stay black. is this a problem?

thanks

.Mike · August 17, 2011, 06:48:17 PM

That is a small amount of the fiber from the paper embedded in the toner. It shouldn't be a problem.

If you see any areas that look thin, definitely touch them up with nail polish.

Mike

jamiefbolton · August 17, 2011, 09:52:25 PM

good then. i'll get to etching tomorrow afternoon hopefully.

frequencycentral · August 18, 2011, 03:31:48 AM

Quote from: .Mike on August 17, 2011, 06:48:17 PM
If you see any areas that look thin, definitely touch them up with nail polish.

My tip of the week: CD/DVD marker pen for touch ups, a lot more precision than nail varnish. Works really well for PCB, haven't tried it on enclosures yet. Hell, I'm signing all my boards now.

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PCB etching not going so well