Here are a couple of more tips that have worked for me:
1) I clean my boards with Comet (the blue-green kitchen/bath cleaning
powered) using hot water and a gray 3M scrubbing pad. Before, I used
regular dish soap and the scrubbing pad, but I had issues with lifting
as well. Since I started using Comet as my initial cleaning method, I
have not had a single lifted piece of toner. It works very well.
2) Just prior to positioning the toner, I wipe the board down one last
time with denatured alcohol and a CLEAN rag.
3) Get your board assembled (if two sided on separate boards) and drill
those holes BEFORE you etch. That leaves a much larger piece of copper
to stabilize the bit you are drilling. It makes a big difference.
4) 1800 rpm is not NEARLY fast enough for bits this small. It's not
fun, but I have had success with a Dremel in the Dremel drill press.
Turned all the way up to 30,000 rpm! Any way to mount a Dremel motor to
your spindle?
Don't give up. Once you have the kinks worked out, it is a pretty neat
process.
Summary of my system:
1) Clean boards -> Comet -> denatured alcohol.
2) Apply toner to board(s). I currently use a laminator, but I did
plenty of boards with an iron.
3) Remove paper or plastic film from the board.
4) Drill two alignment holes in each layer of a double sided board,
diagonals and as far apart as possible
5) Glue boards together with gap filling CA. I use a pair of pins that
are just small enough to go into the holes as alignment pins, then weigh
down with a 5kg weight and let cure for 30 minutes or so.
6) Drill all the holes using my Dremel drill press.
7) Touch up any problem areas with industrial strength Sharpie.
8) Etch.
9) Clean toner off
10) Enjoy!
Clint
On 10/3/2009 4:09 PM, Lee wrote:
>
> Thanks for the hints.
>
> Alignment hasn't really been that big of an issue - I use more/less
> the same method you describe. The biggest issues I continue to have
> are in getting consistent & solid transfer off of the paper onto the
> board. More often than not its just some small part of a board that
> doesn't seem to transfer well - I use the same pressure and
> temperature on the iron and so haven't been able to come up with good
> answer as to why one area doesn't transfer as well as another. When
> doing a double sided its just that much more area for something to go
> wrong. I've also had challenges in drilling the vias where the drill
> bit will lift and then destroy the trace as it comes through on the
> bottom side even if I drill into a sacrificial piece - what seems to
> happen is that the fiberglass will chip and then come lose on the back
> taking the trace with it. I think the major issue is that the motor on
> my mill (which I use for drilling) tops out at 1800 rpm when run
> manually which I think is too slow.
>
>
[Non-text portions of this message have been removed]