Making your own prototype
PCBs
See also the Easy_PCB site for making
prototypes
and/or larger quantities PCBs
at LOW! Prices!!!
From it I ordering all my PCBs
(prototypes & production)
Interesting for radio broadcasting???
Interesting on access control systems???
Interesting on other systems???
What this is all about
With this page I try to
show you one method for creating your own professional-looking PCBs. They
say a picture's worth a thousand words, so I used enough pictures and let them
do most of the talking.
Having a 20-year experience
in making my own prototype PCBs, and having tried dozens of different methods,
I recommend the method described on this page as the best, both in terms of
cost and overall effort. Although the use of a specific unique product is
required, this should not be viewed as an advertisement. I have no
connection whatsoever with the company mentioned. However, I don't see
why a good product should not be talked about for what its worth. I have
photographed all the stages of the process for you to look at.
Required Equipment
- PC with a PCB layout program.
- Laser Printer.
- Press-N-Peel (PnP)
sheets. You can get this from Techniks, Inc. P.O. Box 463, Ringoes, NJ 08551
- Your wife's iron and her full
support. If you don't have an iron, get married.
- Pure industrial-grade Aceton.
- Copper remover.
- A pair of scissors.
- A rasor-sharp cutter or knife.
- Whatever else I might be forgetting :)
The
whole process for making a double-sided PCB is described next. Click on
title link(s) for photo(s).
Step 1 - Printing your PCB from your favorite CAD program
Any CAD program is good enough
for printing your PCB. I happen to use EasyPC for Windows by Number One
Systems (SightMagic). I have used most of the available CAD programs and
for me this seems to be the easiest to work with.
You must use a Laser
Printer. It's also preferrable to use one that doesn't curb the sheet too
much.
IMPORTANT: You must
prepare your PCB so that it also includes a border line at least three
centimeters farther out from the regular board line.
This is how things look
when the Press-N-Peel comes out the printer. You should allow for a
minute or so until the sheet reaches room temperature before touching it.
This prevents the toner to peel off the sheet.
Step 3 - Cutting the Copper Board
Cut the copper board at the
dimensions of the printed layout leaving an extra centimeter on each side.
Step 4 - Cleaning Copper from Oxides
Scrub the copper surfaces
with a wire brush or steel wool to remove the oxides. The copper should
be shining almost like new. This makes it easier for Press-N-Peel to
properly stick on the copper surface.
Cut the PnP just a little
larger than the PCB board you prepared in Step 3.
Use adhesive tape (scotch
tape) to glue the PnP on one side of the board.
Note that I've used an iron
with as flat a surface as I could find. The fewer steam holes it has, the
better. Most importantly, however, it should be flat.
See things from your wife's
perspective. Learn how to iron. It's a little different from
ironing clothes because here you have to be very careful not to make any mistakes
and crease the PnP sheet.
Same as Step 5 but for the
other side.
Step 10 - Line up
Step 11
Step 12
Step 13
As shown in the photographs
above, use a relatively bright light as a background against which to see
through the PnP so that you can line up the two sides using the ouside border
line of your PCB layout.
After alignment, carefully
iron the other side of your PCB.
Step 15 - Are we done yet?
Step 16
Here you see how things
should look when you've ironed enough. You should be able to see the PCB layout
underneath as shown in the photograph. If not, you need to iron some
more. If you can't seem to handle this, beg your wife to do it the right
way for you.
When you believe you have
finished ironing, flush the board with water. This cools it and
stabilizes the toner on the board.
Carefully cut the PnP where
the scotch tape is to release the sheets from the board.
Step 19 - Start peeling
Step 20
Step 21
Step 22
Step 23
Peeling must be done very
carefully. See how many pictures I took? That's to show you how
slowly and carefully you have to remove the PnP sheets so as to avoid destroying
any tracks or pads. (If you do, don't panic, there's always a way to fix
things later, but it's better if you get it right in this phase.)
Now you have a board
without the PnP.
Prepare to remove any
possible imperfections from the board.
Carefully look at the board,
perhaps consulting your PCB layout program. PnP has the tendency to
spread out due to pressure during ironing. The toner underneath does
not. This may make it look as if there are overlapped tracks. With
the knife softly etch the blue where you know (you can actually see it, if you
look closely) there are no tracks underneath.
When doing this, don't
worry too much about destroying the tracks because the Blue peels off only from
where there is no toner. The toner is where your tracks and pads are.
If you happen to destroy a
track, you can use a permanent-ink pen to manually add any missing track
segments.
You can see how clear your
PCB tracks look. In the picture you'll see some very fine tracks (0.4mm).
Use a plastic cable tie
(fastener) through a hole on one corner of the board so that you hold it while
shaking it in the chemicals.
Put the board in a
tupperware-type container.
In this picture we use
FerroChloride but you can use any other copper removing chemical. PnP will
stand against any such chemicals.
You can see the cable ties
when the board is submerged in the chemical.
It takes a while to remove
the copper. Depending on your board size and chemical temperature (the
warmer the better, but not hot), this could take from 5 to 20 minutes or so.
The copper's gone, but
you've got the blues.
Feeling happy about your
work so far won't remove your PCB's blues! You need to use some
industrial-grade aceton. Nail-dye remover, alcohol, detergents, or
cleaning solvents just won't cut it. You need something much
stronger. I have tried pretty much everything else without luck.
When done, and after the
board has dried, look closely for any damage.
This is a necessary step to
help you gain the courage to do this all over again for your next PCB.
After the first two or
three times, you'll start getting the knack. Practice makes perfect,
right? You should probably first experiment with single-sided PCB
creation and when you feel you have mastered the art of ironing, start playing
with double-sided PCBs which require an extra step of very carefully lining up
the two sides.
Now, wasn't that simple?
Have fun.
S.
Pdmtr
http://www.aspisys.com
Don’t want to do it your self? Then you can order your professional made
PCBs at Easy_PCB at LOW
PRICES!!!
Since December 30, 1999
Last modified November 25, 2004