Homebrew PCBs

Hello everyone!

I have recently discovered the toner-transfer method for making PCBs (I have previously used stripboard or dalo pen)

I tried my first board last week and I used the instructions from: http://www.riccibitti.com/pcb/pcb.htm 
For the most part everything seems to work OK but I'm having some issues it seems with the toner spreading out too much.

I am using a Lexmark T522 with original toner, and was using paper cut from the pages of an old "Next" magazine. I used an iron to do the .. ironing.

The printer prints very crisp and clear and the toner sticks very nicely to the copper. The paper is also easy to remove afterwards.

However, while still satisfactory and usable, some of the pads became a bit too big and some of the tracks did not have a well-defined straight edge.

I was able to scratch off excess toner with a knife to make the pads smaller and etched the board anyway. I was using normal components and thick traces with overall quite a lot of room for error but I need to get this issue resolved if I want to make anything with fine tracks or SMD parts.

But I am wondering what I did wrong? I tried twice to iron the board (first time I tried moving the iron around but also moved the paper and smudged the image and had to clean and re-do it). 

The second time I just held the iron on the paper, pressed down and waited about a minute.

Can anyone who has done this before give me some advice as to what might be the cause of my problem??

Thanks in advance.

Perhaps the thin paper is allowing too much heat to come through. Either reduce heat/time or use thicker paper. I have found excellent results with Kodak (CAT 191 2369) Gloss photo paper. The type of toner may be a factor as well.

--- In Homebrew_PCBs@yahoogroups.com, "tda7000" <Tda7000@...> wrote:

>
> Hello everyone!
> 
> I have recently discovered the toner-transfer method for making PCBs (I have previously used stripboard or dalo pen)
> 
> I tried my first board last week and I used the instructions from: http://www.riccibitti.com/pcb/pcb.htm 
> For the most part everything seems to work OK but I'm having some issues it seems with the toner spreading out too much.
> 
> I am using a Lexmark T522 with original toner, and was using paper cut from the pages of an old "Next" magazine. I used an iron to do the .. ironing.
> 
> The printer prints very crisp and clear and the toner sticks very nicely to the copper. The paper is also easy to remove afterwards.
> 
> However, while still satisfactory and usable, some of the pads became a bit too big and some of the tracks did not have a well-defined straight edge.
> 
> I was able to scratch off excess toner with a knife to make the pads smaller and etched the board anyway. I was using normal components and thick traces with overall quite a lot of room for error but I need to get this issue resolved if I want to make anything with fine tracks or SMD parts.
> 
> But I am wondering what I did wrong? I tried twice to iron the board (first time I tried moving the iron around but also moved the paper and smudged the image and had to clean and re-do it). 
> 
> The second time I just held the iron on the paper, pressed down and waited about a minute.
> 
> Can anyone who has done this before give me some advice as to what might be the cause of my problem??
> 
> Thanks in advance.
>

You want the toner hot enough to get "plastic" and sticky.  Too hot
and it just melts, which is probably what's happening in your case
(assuming the print itself is good).

You can experiment with iron heat using a laser transparency instead
of paper.  Print on it, set your iron at a lower heat, and see what
happens.  Keep increasing the iron heat a little at a time, and keep
notes about which settings stick or don't stick, and deform (melt) or
don't.  You want a setting halfway between "just hot enough to stick"
and "just hot enough to melt".

Me, I ended up getting a laminator.