Jim,
I found the same problem with residue in the space between the traces
as you did, using clay-coated inkjet paper and glossy photo inkjet
paper. (Good tip on the laundry detergent; I'll have to try that, as
glossy paper's fast pull-off is easier than rag-content paper's
rub-off process). I switched to catalog paper, non-glossy, from the
Harbor Freight mailed catalog, in fact. I have to tape it to regular
printer paper to get it to travel through the machine unwrinkled.
Some examples are in the Ted-KX4OM photo folder. I'm using a
high-heat Brother HL-2040 (213 degrees C, 415.4 F) that does not do
well with Press and Peel Blue, so I've done experimentation with
various other methods. The last photo, of the simple flash AVR
programmer, gives a good idea of the resolution achievable. Check out
the text on that one.
I start ironing at about 325 degrees F, with the temperature
increasing, and iron with moderate pressure for about 2 minutes on an
EAGLE Cad 3 x 4" board. I put a paper towel, the blue industrial
kind, between the iron and the PC board/paper transfer medium. It
seems to spread out the heat and offsets the steam holes on the iron
problem. By the way, my thermometer is a digital one with an armored
cable to the probe, which is designed for sticking into meat. I lay
the probe tip and shaft under the iron to check the temperature. I
bought it for $16 at Harry's Market here in the Atlanta area.
The problem I still have is fibers from the paper remaining in the
space between the tracks. It amazes me that loose single fibers can
act as a resist, leaving copper wisps on the board after ferric
chloride etching. I usually either scan the board at 600 DPI, or go
over it with a loupe after etching to check for shorts.
I have a better description of the P n P Blue issue and my current
methods, along with board photos, on my site at www.kx4om.com.
Good luck with your efforts with with your toner transfer efforts.
It's well worth it.
Ted KX4OM
--- In Homebrew_PCBs@yahoogroups.com, Jim Hutchinson <jhutch17@...> wrote:
>
--snip---
the common thread in the
> TT process is difficultly in cleaning the paper residue from the bare
> copper after soaking and prior to etching ... the traces I make are
> usually 0.015 or larger and spacing is 0.015 or larger and the residue
> removal has been the most difficult step ... recently I was talking
to a
> chemist friend about this problem and he suggested using some enzyme
> boosted washing powder (either automatic dishwasher powder or cloths
> washing powder) they have enzymes that convert oil to sugar, dirt to
> sugar and cellulose to sugar ... the clay coating on the paper I think
> is close to dirt and the paper fiber is cellulose ... I used Tide
> clothes washing powder (1 tsp to 1 and one half cup of water) at room
> temp ... after the initial soaking (in warm water) to remove the bulk
> paper and the rubbing of the residue with my thumb to remove as much of
> the residue as possible I now soak the PCB in the Tide solution and
> after about 5 minutes, almost all the residue in holes and between
> traces can be easily scrubbed off with a tooth brush ... an additional
> soak may be required for some real stubborn areas ... I now can be
> etching 30 minutes after image transfer ... I found the dish washing
> powder was too aggressive and would cause small pin holes if the soak
> was too long (it works but the timing in more critical ) I would
like to
> hear from someone that has tried this ... it really seems to work for
> me . the toner I use is the toner that comes with my HP1022 laser
> printer ... it softens at about 230 degrees F and melts at 310
degrees F
---snip---
47
> lb ... it is coated on both sides (I buy it at Frys Electronics) ... I
> have had good results with the TT process on small boards and with the
> enzyme soak to remove the residual paper/clay it is also a fast
process ...
> Jim KI6MZ
--snip---