Ironing blue P n´P observations / thoughts / ideas

[Morocotopo]

Hi, just finished ironing and etching 3 PCB´s, and I found a way of ironing that may be useful for getting good results consistently (for me the ironing process has been kind of hit or miss):
I believe that one critical thing in transferring sucessfully to the copper is that the P n´P has to lie COMPLETELY FLAT on the copper and NOT MOVE AT ALL WITH RESPECT TO THE COPPER when ironing. How do I do this?
- Cut the P n´P to size with lots of space on the outside of the image (e.g: 3 to 4 cm.)
- Cut the copper board BIGGER than the size of the P n´P, including the space mentioned before (e.g:2 or 3 cm. more). If you don´t, the P n´ P might curl over the board sides (see below)
- Secure the board underside to a sheet of paper (I used a loop of scotch tape, or you could use double sided tape)
- Tape with the scotch tape the P n´P to the board on all 4 sides so that it lies ABSOLUTELY FLAT, clearing the image by about 1 or 2 cm., and at the same time tape the whole thing to the sheet of paper mentioned before, with the same tape, by using longer stripes than necessary if you were only taping the P n´P to the board. Now the paper, board and P n´P are secured together and won´t move with respect to each other when ironing.
- Put another sheet of paper over the whole thing. Iron.
When ironing, the scotch tape melts and "glues" the whole sandwich together (Paper - board - P n´P - paper) but doesn´t "run" over the image, it glues itself to the papers mostly. I thought that the tape thickness might be a problem with the heat transfer, but in my experience, it´s not. After cooling, removing the papers/melted tape/P n´P is a bit messy but not impossible with some care. When ironing, don´t get melted tape on your iron if you use it for clothes!( ). With this method, I got clean images on the copper, and had to do no retouching at all on one board (nice, thick traces) and just one little touch up in one place in the other two boards (thinner traces)
- Cut the boards to final size, trying not to scratch traces. Scrap the tape residue on the underside of the board. clean, drill, populate, make noise.
Yes, you waste some P n´P and board, but if it gives you good results, I think it´s worth it.
This worked well for me, It might be of some use to other people. And I hope I was clear in my explanation!

Morocotopo

[RaceDriver205]

I find a few things need to be remembered to allow a perfect transfer.

• Have the iron at the perfect temperature - takes a few tries but you get it eventually
• Dont press the iron into the board too hard - can cause smearing of the toner
• Rub board first with a bit of iron wool until shiny, and then wash with a bit of hand soap
• Iron for the right amount of time - again you work this out eventually

If you get errors on the board, you can use a etch-resist pen to lay tracks, or something like a fine screw-driver to remove bridges. Its great stuff it really is - if you have a laser printer. I can churn boards out once I get into it.

Oh, and to stop the PnP slipping, hold it in position by pressing it into the board hard with your thumb - even when you laying it flat. The iron will cause the PnP to stick, and then your free to release it.

[Morocotopo]

Yes RaceDriver, all you say also applies, what I posted is to be considered IN ADITTION to all the usual instructions on various sites.

[markm]

I have found if you just rub it a tiny bit with a finger it becomes static charged and will stick anywhere.

[stumper1]

FWIW-
I have found that if you pre-heat the iron to the proper temp then pre-heat the board by resting the iron on it for ~5min - the PnP will "stick" to the board as soon as it touches it.  No chance of moving/smearing BUT you gotta get it right the first time.
It also seems to me that the single most important factor (IMO) is that everything is CLEAN.  That means the board, the PnP AND the iron.  To clean the board I've been using steel (iron?) wool to polish out any small scratches and then using Lysol Basin Tub and Tile cleaner and hot water.  The Lysol cleaner was suggested to me by someone to clean copper for a totally different purpose - since I still have some, I use it - seems to work great.

[Transmogrifox]

I used my flat electric skillet and a rolling pin with good results.  The skillet helps get better controlled heat uniformly across the entire board.  This is in addition to all mentioned above.   I also had good results cleaning copper with dish soap (in agreement with an above post).

[RaceDriver205]

Yes RaceDriver, all you say also applies, what I posted is to be considered IN ADITTION to all the usual instructions on various sites.

Ok Ok moro. Just checking.