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Guest timofer

Hey,

      I found this article quite usefull,  the method described in it is pretty much like the press-n-peel but a lot cheaper  ;)

http://www.pablin.com.ar/electron/trucos/placaci/index.htm

Also some good tips for the non experienced are:

* Never use steam when you are ironing the board

* Don't move the iron just let it sit firmly and do not  apply too much pressure.

* Laser prints work best but a regular photocopy does the job.

Regards,

Emanuel

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Emanuel,

I use that technique here with good results, but I was afraid to do my MB64 board, so I sent it off. The text I learned most of it from was here:

http://www.fullnet.com/u/tomg/gooteepc.htm

It may have a bit more detail to it, if you're interested. The JetPrint paper they mention wasn't hard to find. There's probably a bunch that will work. One catch I did find, was the toner. On my first try, I ran my copies and some of the paper up to a local Kinkos (print shop) to be printed onto the photo paper. They looked fine, but the image barely came off the paper when I heated it. I ended up with this fuzzy, useless transfer, which wasn't dark enough to block the etchant. Just out of curiosity, I took my next one to my father's work, and had them print it from a standard copy machine, onto my photo paper, and it was perfect! The image peeled neatly off of the paper after just a minute or two in the water. With practice, I was able to get nice clean lines and readable text labels. It may be worth checking a different machine, if your results are discouraging.

The ironing and etching procedures were the ones which required the practice. I've done a couple small amps, and am going to try to start on a board for an EPROM/Atmel/PIC programmer tomorrow (the board layout is frightening).

                          - take care,

George

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  • 3 months later...

If you want some real shiny paper then get some self adhesive paper and remove the sticky sheet.

Print onto the shiny side of the backing paper.

I got best results by using masking tape over the whole paper when ironing. The softness of the masking tape makes for a nice pressure all over. makes up for any undulations.

I let my board cool naturally. When using the self adhesive backing the paper seperates itself from the board. I have never tried to cool the board and paper in water.

Laser worked best. try to get one with least amount of turns in ejecting as the toner really comes off the backing easy.

I must pay homage to LO for the details he passed to me regarding this process. ;) ;)

Regards

Ian

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  • 3 months later...

Using this method it's really hard to do boards as fine as the MBHP boards, which often have traces running between IC pins.

What happens is that the toner tends to spread a bit when you apply pressure from the iron.  It makes the tracks just a little bit wider -- enough to cause problems.

Also watch for little pinholes, you really do need to dab with a permanent marker prior to etching.

I use this method a lot, however, and have generally had very good results, but I'm re-laying out some boards so that I can continue to use this method to make some MBHP stuff.

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  • 1 month later...
Guest psytron
Using this method it's really hard to do boards as fine as the MBHP boards, which often have traces running between IC pins.

listen to ian hurlock and use masking tape over the side you are going to iron.

i have used this method a few times without the masking tape and the images can blur with only a little too much pressure.

i have not used the backing paper from stickers but the masking tape is a [glow=red,2,300]BIG[/glow] advantage and makes for a board that does not need tidying up b4 you etch.

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  • 2 weeks later...
Guest psytron

the tapeused is "maskin tape" and is called the same in all eng speaking countries i think. it is a sort of paper tape light yellow in colour (usualy) check in harware stores and esp painting places (will be more e4xpencive here tho)...

goodluck

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  • 1 month later...

Hey, I got all excited to try the method using the adhesived-back paper backing, but as I went to peel the paper to free the backing, I realized the backing was slit diagonally and I wasn't left with a sheet I could feed into the printer.

So what type or brand or whatever of adhesive paper are you using??

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  • 2 weeks later...

Well, I found some of the right stuff. Avery adrress labels, actually :)

And I am VERY pleased with the results!

So very much faster!

I just designed, printed, ironed and etched a small board in about an hour and a half, and the first hour was wrestling with Eagle!

Woohoo!

The adhesive-backing method just trimmed several hours off of my boardmaking time!

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What my previous post didn't mention is that I cheched the "mirror" box in Eagle's print dialogue when I shouldn't have, and didn't discover it until I had already drilled all the holes. So I had to start over :)

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  • 5 months later...

You can use a sharpie.... but i wouldn't try it on theese designs. IC pins need to be perfectly aligned.

I had minimal succes with the above methods, though it got better everytime, i think it takes a lot of practice.

I read somewhere recently about sending the board and toner transfer paper through a laminator instead of using an iron, supposed to be more even pressure. Apparently there are laminators made specifically for this purpose. i may try one day, with a cheap laminator, but i'm not shelling out a bunch of money.( if it doesnt work well, i can always have luggage tags...)

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hi guys

i wonder what princip does it use?

toner in not resistant to echant? or is?

The best way to think about toner is that it's -like- powdered plastic while still in the printer, and it's melted (fused) to the paper.  The toner transfer process is simply re-melting the toner again so that it sticks to the copper.   ;)

The Ferric Chloride only attacks metal (but will stain anything, including porcelain under water!), so the transferred pattern is relatively safe when in the etchant.

When I do single boards, or don't have enough etching to do to justify filling an etch tank, I do the normal transfer, then use toner reactive foil (usually used to make certificates w/laser printer) fused on to the resist, to make the resist a lot stronger.  That allows me to pour a tiny amount of etchant into a tray, then use a sponge to "rub etch".  This is the most messy method, you MUST use gloves to do this.  But I can etch a board this way in half the time it takes to run it in the tank, use almost no etchant, etc.

See more about this method at: http://www.pulsar.gs/1_tts/c_pcb/new_tricks/all_writeups_support/technique_contact_etch.html

Pulsar also sells large rolls of toner reactive foil here:

http://www.pulsar.gs/5_online_store_no_frames/1_tts_store/c_pcb/master_PCB_listing.html#Anchor-21683 (this is the cheapest way I know of to buy this stuff!, it's a large roll)

Have fun!

SmashTV

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  • 4 weeks later...

I use the "Laser" transparency sheets in my laser printer all the time without heat problems. I have tried the "iron on" technique a few times with fair results on simple boards. However, I invested a few bucks in equipment and now used photographic techniques and get excellant repeatable results. The method is quite simple. You print a positive image of the PCB layout on the transparency and place it on a pre-sensitised blank PCB and hold it tight to the board using a piece of glass. Then the board is exposed with an ultra-violet fluorescent light for 5 minutes. Once exposed the board is placed in the developer and in seconds the exposed portion of the resist dissolves away leaving the unexposed portion on the board. The board can then be etched in the normal fashion. I use MG Chemicals products found here http://www.mgchemicals.com

Using this technique I can easily produce board with 15 mil (0.38 mm) traces on a 25 mil (0.64 mm) grid and can run traces between IC pads spaced 100 mil (2.54 mm) apart.

Although this method is a bit more expensive than others it reliably produces extremely high quality boards.

Hope this info is useful.... :)

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I am about to make the switch to this method, have been planning to since my first not so great attempts with the transfer method.( I did get some usable boards, but even they could be better). Will this work with Inkjet transperencies? or shou;d i just get a cheap laser at an auction or something. the main reason i havent got one so far is that the toner would cost me more than the printer it seems. not so bad if i use it only for pcb's i guess.... how many sheets do you get from a toner cart before it dies?

I have read that the photographic process is the way to go, if you can afford the equiptment, have the space to do it, and can stand some more chemicals.

Thanks for the link.

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Guest psytron

i have a laserjet from hp.

toner will last you for ever if you only use it for pcbs.

i will give the LASER tranceparencies a go. perhaps these are reusable (for a while).

i have a laminator as well so i will give this method a go as well.

keep you posted

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