I appreciate your response. I did notice that the default size of
vias in Eagle is kind of small and leaves no room for error. I
bumped them up to 15mil pads. Most of my lines are 10 mil and space
between is 8 mil. The single sided boards that I've done came out
99% good, except a minor line being broken but fixable. When you do
a dbl sided board do you use defaults in the routing parameters or
do you change them and favor 1 side to give less traces on the top?
What is the smallest drill bit you use? Do you "tin" the board when
finished etching?
Thanks!
--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
>
> Its not hard at all to get good registration with double sided
boards.
> I dont even bother making single sided anymore. You need to take
> care when ironing to ensure that the paper doesn't move. When I
was
> using an iron, I would tack in the middle and work outward.
>
> In terms of line width, I can do 10 mil pretty easily though I
prefer
> 12 mil. You can get 12 mil through 100 mil pitch parts and it
stands
> up to the vagaries of the etch tank a little better.
>
> Yes, I use wire in the vias and solder both sides. I'll use what
ever
> wire I have that's scrap. Since I got a couple hundred feet of
scrap
> cat5, I've been using that. 28 ga, I believe. I thread the wire
> through all the vias and solder them in one pass on each side of
the
> board. I then use the wire loops for continuity testing and clip
them
> off as I determine the via is good. Its a good, cheap and fast
technique.
>
> I know that others use eyelets but my one experiment with them was
a
> mess and I wound up chucking the board. You need to make your vias
> pretty big (much larger than the eagle default).
>
> The biggest issue I have is via placement. Since I use a wire to
> complete the via, one can't be put under parts that are flush with
the
> PCB. Also, you want to be careful not to place a via too close to
a
> pad as the heat of soldering the pad can cause the via wire to drop
> out. I suppose if you use eyelets, some of this can be overcome.
I
> generally dont put vias under things as it allows me access to go
back
> and touch it up if I muffed the soldering.
>
> Have fun!
>
> Phil
>
> --- In Homebrew_PCBs@yahoogroups.com, "Bob Weiss" <BWeiss@p...>
wrote:
> >
> > Using the "Staples Paper/Ironing" method, what are the best
> > achievable results you have gotten for a double sided board? I
mean
> > what are the thinest lines (in mm or mils) and space between
them.
> > The reason I am asking is because I just designed a double sided
> > board that is pretty complicated (I use Eagle Pro) and I don't
want
> > to waste my time if it can't be done at home. I have done single
> > sided boards before with this method and have gotten great
results.
> > The best I can get this particular board to route 100% is if I
use
> > alot of via's. If I go with a 4 layer and send it out ($$$) then
its
> > not that hard to route. Just trying to get some your prior
> > experiences and see if I should proceed. Thanks for taking the
time
> > to reply.
> >
> > Also when dealing with vias how do you solder them? I was
thinking
> > of using thin (30 guage), bare wire and solder it on both sides
of
> > the board. Does anyone have any better ideas?