I find the toner transfer process (to PCB and enclosure) one of the most tedious and tricky steps in pedal making. Does anyone have any advice to make this process more reliable and efficient? Thanks, BM
Lots of threads about this previously. John Lyons has a tutorial, IIRC. Use the search button up top and try "toner", "transfer", "ironing", "printer", etc.
Once you have your procedure down it will get easier.
No "ONE" technique works for everyone.
John
I have found two main differences between ironing enclosures vs pcbs...
1.) enclosures are aluminium and act as heat sinks by cooling the artwork, which prevents the toner from melting and sticking to the box.
2.) enclosures may not be as flat as the iron, or the iron may not be as flat as the box. A pcb will flex and conform to the iron under pressure, but an encosure won't.
Suggestions...
1.) preheat your enclosure in an oven, or the iron before apply your artwork.
2.) use two layers of parchment paper (used in cooking) between your iron and the artwork. This allows
the heat to be more evenly distributed... and it provides a little "give" so the artwork will conform to the
uneven surface of the enclosure.
3.) practise, practise, practise.
For pcb transfer I believe it is all paper what matters. As soon as you found the right paper it will be so easy!
I found mine, Epson S041126.
I have been searching the right photo paper for about one year.
Some were quite good, some were bad and even after ironing more than 5 min i was having only 50% of the toner transfered.
Then i found the perfect solution: magazine paper!
It needs very little time to iron, i think because the paper is very thin, and when you pull off the transfer stays on the pcb perfectly.
And it's for free!!
Now i am looking for a chemical for eliminating all the paper on the pcb and leaving only the toner. any suggestion?
I once tried paper that was reduculouse. It stuck to the iron en started melting.
I use press-n-peel blue transfer film, which was designed for the job. Works every time once you get the technique down. The larger the PCB the harder it is to get a perfect transfer (which is true for any method I guess), so start small and work up as you get used to using this stuff. I've made large preamp boards with it, but I cut my teeth on small disto pedal boards etc.
PCB prep is also a big factor in getting a good transfer. Some recommend getting the copper clad board mirror smooth first, but I disagree with this approach. I use a wet Brillo pad (a UK product - essentially a coarse wire wool scourer impregnated with detergent) to clean the board while scuffing it up and taking off surface oxidation - the copper ends up flat and shiny but covered in minute scratches - a 'brushed copper' look. I get great transfers this way because the surface has a 'key' for the toner to grab onto.
As noted before, the search function is your friend - PCB fabrication has been covered many times before.
Quote from: kupervaser on July 21, 2009, 06:55:59 AM
I once tried paper that was reduculouse. It stuck to the iron en started melting.
Some companies produce inexpensive photo-paper that is coated on BOTH sides. I find this to be the case when the photo-paper is cheap and not especially glossy. I gather that when the finishis not very glossy, it is easier to coat it on both sides than it is to explain to people how to identify the "glossier" side or field the complaints from people about poor image quality. Since that stuff is generally marketed as being for inkjet printers, there are also no concerns about the emulsion melting off in laser printers.
The bottom line is that what you experienced was more than likely one of these cheap types, and what you found sticking to the iron was either the emulsion on the other side of the paper (because you found it hard to identify the good side) or the emulsion on the other side because
both sides were "the other side".
bestpractice when using photo paper is to buy the glossiest stuff you can find, and if both sides seem equally shiny, avoid it.
I guess my original thread had to do with perfecting the process. I generally preheat the surface, apply pressure for a minute or so then target small spots - soak for 2-3 minutes in hot water. Even with this approach I still have the transfer lifting. (I use Staples gloss photo paper).
I've never tried the parchment paper trick but might try it next time.
Really? You use hot water? This might be where you're going wrong. The idea is to get the toner hot while it is in contact with the copper, then rapidly cool the whole mess in a running stream of cold water for several minutes until everything is thoroughly cold and the toner has fused onto the copper. Once completely cooled, removing the transfer paper leaves the toner behind because the copper has a better 'grab' on the toner than the glossy paper.
I use a method that gives excellent (At least for me) results using glossy magazine paper.
I prop the iron horizontally in a vise. I have a small paint roller that was used but never washed, it´s rather firm but not rock hard.
I place the PCB copper side down with the printed image on the iron and start rolling on the soon to be component side. After a few seconds the copper side is nice and hot and the roller is pretty warm.
I turn the board over and start rolling the transfer side. The iron keeps the board nice and hot from underneath. The roller is malliable enough to press down on and make a nice clean transfer along the edges.
The pressure from the roller is evenly distributed so as not cause any bleeding with thin traces.
Works great with enclosures too.
The heated roller will stink of paint when heated but dissapears after a few transfers.
Good luck.
I'm passing this along from a similar thread where I saw it just a few days ago... (http://www.diystompboxes.com/smfforum/index.php?topic=77758.msg639256#msg639256 (http://www.diystompboxes.com/smfforum/index.php?topic=77758.msg639256#msg639256))
In that thread, Daniel Schwartz recommended the backing paper from stickers (like Avery labels after all the labels are gone).
I tried it, and couldn't believe how well it worked. There's very little ironing required for the transfer. After it cools down, the paper almost floats off leaving the entire pattern on the PCB, and nothing on the paper. It's also translucent, so you can see through it to align it easily.
Until now, I thought I had a pretty good system (hp ink jet transparency paper through my samsung color laser), but this method blows it away!!!
So Thanks! Thanks! Thanks! to Daniel. And to anyone else - TRY IT! You'll never miss the long hard ironing/soaking/peeling/cursing process again.
Thanks for all of your replies. I knew I was doing something wrong.
Regards, BM.
Thanks "axg20202" for explaining why I was getting different results with press-n-peel blue.
I was using 0000 steel wool for a mirror like finish & getting partial transfers (75% to 95%.)
A couple of weeks ago I just grabbed an SOS pad & got a scratchy (but clean) looking surface & voila - transfer was 100% - no touch up - looked like it was silk screened. Used the darkest setting for my laser printer (Samsung el-cheapo) & just below cotton setting on the Iron. 4 minutes pre-heat & 4 minutes transfer.
When I start to pre-heat the iron - I also throw some ice cubes in a large bowl of water & throw the ironed transferred PCB in there before I separate.
- Jimbeaux
I updated this a bit just now...
http://www.basicaudio.net/How-to-make-PCBs.htm
john
Hi John, the link seems to be broken.
Has anyone had any luck using parchment paper or wax paper for toner transfers? The sticker back paper brought that to mind. I might try experimenting.
Forgot the L at the end :icon_redface:
http://www.basicaudio.net/How-to-make-PCBs.html
john
Thanks John. Great tutorial by the way.
John,
I checked out your tutorial... nicely done!
Just a couple observations/comments:
Somewhere in the middle it says you can't really reuse the acid, then at the bottom it says you can. I have always reused mine. In fact, disposal of the used solution is a real environmental hazard (which is why I never put it down the drain). Even small amounts of dissolved cupric chloride will kill the bacteria used in waste treatment plants. I'm no chemist (or waste expert), but there's a boatload of information about using/reusing this etchant here: http://members.optusnet.com.au/~eseychell/PCB/etching_CuCl/ (http://members.optusnet.com.au/~eseychell/PCB/etching_CuCl/).
You also mentioned using 40% Hydrogen Peroxide. I haven't been able to find any that concentrated, and I'm not sure I'd want to. The stuff I usually get is "ClairOxide 40", which is a 12% hydrogen peroxide solution. I think I'd be scared to try an actual 40% solution.
Finally, my jaw just dropped wide open when I tried the "label backing" media and saw how well it worked. Imagine skipping the whole soaking/scrubbing step... worth a try don't you think?
I re use the solution. Initially I did not. I just updated the article and it seems a little inconsistent.
I do save the used solution. I ought to look into where to take it some time soon :icon_eek:
With peroxide the 40% is the best for your money. Why pay for water which is the other 60%...
If you wanted a lesser percentage you can just add water. Most beauty supply places sell it.
I'll have to try label backing again. The first time I used it I did not get good results.
John