How to make a PCB for my minature Robot - etchant
Archiver
Posts: 46,084
Hi,
By now you've got at least two methods. UV and Ink Resist.
Here's more on the resist method.
The Ink resist is the simple first time user method.
Radio Shack sells a kit of two boards, 3" x 4" and the
solutions for etching and resist pen and a drill bit too!.
The resist method is that you put on some type of film
that resists the etching solution. Most permanent markers
work. If you can't see copper it's probably thick enough to
resist the etchant solution.
The Laser Printer as resist method works because laser toner
is really just plastic. You print an exact size layout on
a piece of paper then iron it onto the copper (after a good prep)
then what you are left with is a layout on the copper that
resembles your circuit.
Then, with a lot of patience, a magnifying glass and a
really juicy marker, you fill in all the pads, lines and
any area that is not really black. Dabbing is better than
drawing.
One note is that when you print, you are making either a positive or
a negative. This means that you must pay close attention to
the layout on the printed sheet.
Place your chips on the printed sheet. If they fit properly, you're
good to go.
Tape the image to board then with your iron on Cotton/Linnen,
heat it up for about a minute. Let it cool down. IF you mess
up, you can remove the plastic with solvent and try again.
A note here is that if you get 80% of you lines you can either
try for 100, or use the pen to fill in the blanks.
The iron transfer will reverse the image, then when
you drill and solder, your image is on the bottom of the board.
Be careful about drills, a 1/16 (0.0625 inches) drill is
small, but IC's are spaced at 0.1" so there is little room for
mistakes, and none for traces between holes.
I don't have my web site up, but I sell drills in sets of 5
in metric sizes starting at 0.5mm (0.0197") in increments of
1/2 mm. And fractional in roughly 0.005" increments.
Be careful about how to hold these little pins. Some
drills chucks will not grab them. A bad idea is to use an
exacto knife holder with a cross cut (as opposed to a singe
blade opening)to hold the drill, then put the larger diameter
handle in your drill press. This will work for a small
period of time, but will wear out if the drill spins.
I also sell a small drill chuck for these drills.
(end of shameless self promotion)
Another tip is that after your set and before you etch,
any traces that are close together, you can gouge with
a carbide scribe. This is a small pointed device like a pen
to scratch glass or steel. When you gouge the copper,
you make it easier for the etchant to work and are
insured of good separation.
I'm working on a full write-up of this for my web page,
but these are the basics. If you want more details let me know.
Dave
--- In basicstamps@egroups.com, nags <nags@c...> wrote:
> Hello,
>
> I'm at a point where I'd like to make PCB for my minature robot.
Presently,
> it has three 1" x 1" Radio Shack general purpose PCBs stacked one
above the
> other using some spacers. I have 30 day trial version of the
Protel's s/w. I
> guess my question is many fold:
>
> 1. How to tell Protel the dimensions of my board
> 2. After done drawing, how do I go about making the pcb -
with
> steps involved.
>
> I know most of you guys have a lot of experience doing PCB stuff -
if you
> can throw some light and point me to some text (or web site)
explaining the
> process, that'll be really great!!!
>
> Thanks in advance
> nagi
By now you've got at least two methods. UV and Ink Resist.
Here's more on the resist method.
The Ink resist is the simple first time user method.
Radio Shack sells a kit of two boards, 3" x 4" and the
solutions for etching and resist pen and a drill bit too!.
The resist method is that you put on some type of film
that resists the etching solution. Most permanent markers
work. If you can't see copper it's probably thick enough to
resist the etchant solution.
The Laser Printer as resist method works because laser toner
is really just plastic. You print an exact size layout on
a piece of paper then iron it onto the copper (after a good prep)
then what you are left with is a layout on the copper that
resembles your circuit.
Then, with a lot of patience, a magnifying glass and a
really juicy marker, you fill in all the pads, lines and
any area that is not really black. Dabbing is better than
drawing.
One note is that when you print, you are making either a positive or
a negative. This means that you must pay close attention to
the layout on the printed sheet.
Place your chips on the printed sheet. If they fit properly, you're
good to go.
Tape the image to board then with your iron on Cotton/Linnen,
heat it up for about a minute. Let it cool down. IF you mess
up, you can remove the plastic with solvent and try again.
A note here is that if you get 80% of you lines you can either
try for 100, or use the pen to fill in the blanks.
The iron transfer will reverse the image, then when
you drill and solder, your image is on the bottom of the board.
Be careful about drills, a 1/16 (0.0625 inches) drill is
small, but IC's are spaced at 0.1" so there is little room for
mistakes, and none for traces between holes.
I don't have my web site up, but I sell drills in sets of 5
in metric sizes starting at 0.5mm (0.0197") in increments of
1/2 mm. And fractional in roughly 0.005" increments.
Be careful about how to hold these little pins. Some
drills chucks will not grab them. A bad idea is to use an
exacto knife holder with a cross cut (as opposed to a singe
blade opening)to hold the drill, then put the larger diameter
handle in your drill press. This will work for a small
period of time, but will wear out if the drill spins.
I also sell a small drill chuck for these drills.
(end of shameless self promotion)
Another tip is that after your set and before you etch,
any traces that are close together, you can gouge with
a carbide scribe. This is a small pointed device like a pen
to scratch glass or steel. When you gouge the copper,
you make it easier for the etchant to work and are
insured of good separation.
I'm working on a full write-up of this for my web page,
but these are the basics. If you want more details let me know.
Dave
--- In basicstamps@egroups.com, nags <nags@c...> wrote:
> Hello,
>
> I'm at a point where I'd like to make PCB for my minature robot.
Presently,
> it has three 1" x 1" Radio Shack general purpose PCBs stacked one
above the
> other using some spacers. I have 30 day trial version of the
Protel's s/w. I
> guess my question is many fold:
>
> 1. How to tell Protel the dimensions of my board
> 2. After done drawing, how do I go about making the pcb -
with
> steps involved.
>
> I know most of you guys have a lot of experience doing PCB stuff -
if you
> can throw some light and point me to some text (or web site)
explaining the
> process, that'll be really great!!!
>
> Thanks in advance
> nagi