Toner transfer smudges

Discussion in 'General Electronics Chat' started by Shagas, Jul 24, 2013.

  1. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    Hello,

    I've tried using the toner transfer method at least 6 times for simple PCB's but I keep getting crappy results . I've seen over 6 tutorials including on youtube and also Bill-Marsden's post but none mention my following problem :

    I keep getting my traces smudged when ironing the design on the board .
    I use thin (I think 125g glossy paper for laser printers) .
    I don't own a laser printer myself so I print it at my friends house who has some xerox workstation for 250 bucks.
    At first I thought that the iron was the problem so I got myself a completely FLAT bottom iron and still I get smudged results .
    Here are some pictures :

    tonertransfer1.jpg
    tonertransfer2.jpg


    You can see how the trace width is very inconsistent and wavy like in some places.
    What am I doing wrong? Am I pressing too hard (I don't)
    I've tried using a lower temperature , that doesn't help either.

    Should I use thicker paper maybe??

    The pictures were taken through a magnifying glass with my phone ( I just realised that I can actually do that )
    The traces are coated with silver.

    The thing is that it's not sooo much of an issue for simple stuff with wide spacings , but I cannot make smaller pitch and finer pcbs because i'll be getting shorts everywhere.

    Any advice or help is welcome.
     
  2. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    Likely you are getting a miniscule shift in layers when you slide the iron over them. Try lifting and lowering the iron in a pattern to cover your transfer...
     
  3. Wendy

    Moderator

    Mar 24, 2008
    20,764
    2,534
    Put a towel or cloth over the transfer, your iron is sticking to the paper and moving it. It could also be varying temperature too much. This is why I went to a laminator instead.

    You may also need to play with temperature and duration. If you melt the toner too much it will smear.
     
  4. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    It's likely . But I try to follow tutorials where they say that I should Drop the iron on for a minute or so until it sticks and then I can ride around all I want .


    @ BILL_M

    Will putting something as thick as cloth still transfer the heat to the transfer?
    I was thinking of putting a metal plate or a thick piece of paper at least between the iron and the transfer .

    In tutorials they always advise to go to max temp . I tried using half temp and 75% temp and still get same crappy results .

    I ride around on the transfer for quite a while because if I stop to early then the tracks don't always transfer.


    There is one combination that I haven't tried yet and that is very high temperature and low Riding time. Maybe that would work
     
  5. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    Yes in your tutorials You use a laminator .
    So if I get some cheap second hand laminator you think it would work good?

    Also i'm thinking of trying thicker glossy paper and higher Iron heat . What do you think?
     
  6. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    Likely not... I "acquire " used / castoff technology, for a hobby / mad money... Hence my Nom de Plume :D

    I had 6 laminators discarded by a local school system, and was only able to cobble one working unit out of all 6.

    If you could find a used unit that was not beat to hell, or allowed to idle hot for weeks on end, you may get lucky.
     
  7. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    I meant If i got a working second hand laminator :)
     
  8. GopherT

    AAC Fanatic!

    Nov 23, 2012
    5,981
    3,712
    I use a paper towel folded in half as a cushion to distribute pressure and distribute heat across the laser printed paper.

    If you are still seeing the issue, try lowering the iron temperature. Don't expect to get traces under 10 mil (0.010 inches).

    Finally, don't expect to get to quality boards from some cheap PCB material from eBay. Some material is on there because it is off-spec. The material that smells like sh!t will give off a bunch of gases when you iron it and blister the board and the traces.
     
  9. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    Hmm , yes paper tower might work .

    Can't expect to get traces under 10 mil? That's 2,5 millimeters in metric .
    I've seen people on youtube get less than 1 millimeter without using any special equipment :/


    Nah my pcb's come from a reliable source (at least I think)
     
  10. bance

    Member

    Aug 11, 2012
    315
    34
    You got the decimals wrong 10 mil =0.254mm:D
     
  11. BobTPH

    Active Member

    Jun 5, 2013
    782
    114
    The traces will bleed out a little bit. If they do too much, you are using too high a temp. I put my iron at about 4.5 where 6 is the highest setting.

    Bob
     
  12. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    hmmm... I guess 0.25mm is acceptable :)
     
  13. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    Ok thx i'll play around with the temp .

    ********************

    Has anyone compared Toner transfer method to Photoresist exposure in terms of quality and precision?
    I'm guessing the photoresist gives a higher quality . Can anyone confirm this?
     
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