Homebrew PCBs

Hi Mikey

I also recently started using toner transfer, but unlike you, I bought
  a laminator from the beginning (a massive russian laminator), and I
do think it does some, if not all, the difference. From reading a lot
of messages here in the group I expected to have some problems in my
first attempts. 
I bought a case of verbatim photopapers and printed a schematics,
using a HP laserjet 4m. I cleaned a copper clad board with steel wool
and alcohol and ran it through the laminator three times. I then
poured some dish washer soap on the paper and rubbed it with my thumb
under water until the paper came off. To my supprise the result was
perfect, even the fine lines were perfect. 

I think that if the paper you have used works great in some parts on
the copper clad board and bad in others, then it's not likely that the
paper is the problem. Either it is the cleaning of the copper that
went wrong or it is the heating process of the paper that is causing
the problem. Since the cleaning is really easy, I guess it is the
uneven heating (ironing) process you should focus on. With a laminator
(with a motor to feed the paper at a constant rate) you will be able
to fine tune the process, leaving out the stochastic nature of the
iron/sister combination  :-)

I will try to make some experiments to see how fine lines I can make
and also provide much greater details of my settings (feed rate,
temperature, paper type, ...) and post them here - if this could be of
interest.

One thing is for sure, I will stop doing photo pcb's, since toner
transfer is so easy (don't hope it is beginners luck).

\martin

--- In Homebrew_PCBs@yahoogroups.com, "milkgonefunky" <mikey@m...>
wrote:
> Howdy,
> I have recently just started trying the toner transfer method with
> very odd results. I started trying a variety of papers (I am in
> Australia) and found that HP Premium Glossy Photo blah blah paper
> worked. The first thing I did was a power supply for uni project.
Yeah
> it worked okay. Fair few pinholes, but I put this down to
inexperience.
> 
> My next project was a whole heap of gainclones (amps, check
> diyaudio.com). Every single one came out perfect, well all except
the
> super thin traces which I had for a keepout layer. Not important at
> all. I was printing with a HP Laserjet with HP toner cartridges.
> 
> Just the other day I was making some bodgey circuit and I did the
same
> process, except the toner wouldn't stick to the board at all.
Usually
> I would get the paper sticking to the copper, but that wasn't even
> happening. I thought it might be my iron, cause my sister constantly
> leaves it on when she leaves for work in the morning and it stays on
> all day pretty much every day, so I figured it might be stuffed and
> not getting hot enough. Tried a few different irons and still the
same
> result. I eventually got enough toner to etch but still the paper
> wasn't sticking like the time when I got the great results. I
figured
> perhaps the paper might've been exposed to the air too long? I
noticed
> some other photo paper I got with my printer (can't print on it with
> laser though, goes all weird) comes in a foil sealed bag. Maybe all
> photo paper has this problem? My other thoughts were that the copper
> has to be hot too, and perhaps we weren't getting the copper hot
> enough. I was thinking if this is the case, that heating it first
with
> a heat gun, then pressing the paper onto it, then ironing it would
help.
> 
> Anyone able to help me explain what is happening here or if anyone
> else has had these problems?
> 
> Can anyone else in AU suggest paper that works great? Even
printers? I
> am lookign at a laminator soon from Officeworks. Do they make a big
> difference in the results over an iron?
> 
> -Mikey