More time and more pressure are what you need. If the toner falls off,
it did not get hot enough or there was not enough pressure to 'fuse' it
to the copper. I press an iron set at 'cotton' on the board for 1
minute. It does seem to work best if the iron is heating the board which
heats the paper. If you press too hard, the toner will spread. I have
had at least a 70% success rate on small boards 100mm^2 or less. I have
also made a couple of double-sided boards as well. I have never dried
the paper prior to useing it.

It sounds to me that the best results could be obtained with a modified
plotter (If you don't mind wider traces). There is a web site somewhere
out there on which a claim is made as to the best ink to use.

Now I have to find out where I can by some copper to test. How does this
affect the corona wire and power supply? I would imagine you might be
able to nearly short the corona to a ground.


Joel A. Kunze


Sean Breheny wrote:
>
> Hello all,
>
> I have a question regarding this whole thread: I have tried using the
> special paper that you print onto using a laser printer and then "iron" on
> to the board, and I have had very little luck (this is NOT the copper foil
> paper, which I have never seen). What I did was to print my patter using a
> laser printer. I baked the paper slightly in an oven (I also tried not
> doing this). Then I thorouly cleaned and even lightly sanded the board,
> placed the paper on it, and then applied heat and pressure. To apply the
> heat and pressure I tried both an iron and a commercial t-shirt press on
> max. heat and on medium heat. I then within 20 seconds placed the
> board/paper combination into  water until the paper separated. I ALWAYS got
> an unsatisfactory result, some of the toner would fall off in the water and
> I would be left with a spotty board. I even called the manufacturer and
> tried his suggestions. Nothing worked. I even tried several different
> batches of paper. To no avail. Any idea what I was doing wrong?
>
> Thanks,
>
> Sean
>
> At 11:04 AM 1/28/98 +0000, you wrote:
> >Is there a web site where I can purchase necessary components to try
> >the copper foil technique on my own?
> >TIA
> >AY
> >
> >> Actually, the copper foil technique was developed precisely because it
> >> is easier than the heat transfer method, and produces vastly superior
> >> results.  It is very dificult for most people to get consistent
> >> results with the TEC sheets (and similar products), and the very fact
> >> that the toner is transferred twice limits the minimum reliable trace
> >> width.  This new method promises high quality prototype PCB's with a
> >> minimum of fuss.
> >>
> >>
> >> CIAO - Martin.
> >
> +--------------------------------+
> | Sean Breheny                   |
> | Amateur Radio Callsign: KA3YXM |
> | Electrical Engineering Student |
> +--------------------------------+
> http://www.people.cornell.edu/pages/shb7
> mailto:shb7@cornell.edu
> Phone(USA): (607) 253-0315