More LED's - Again

wrote in message oups.com...
RST Engineering wrote:



But the paper
HAS to come apart if we want to leave ONLY the thermo-plastic material
bonded to our circuit board. So use the cheap stuff. And soak it in
warm soapy water. Then scrub it with a tooth brush or whatever -- get
ALL of the paper off of the thermo-plastic.

One of those green kitchen pot scrubbers does a pretty fair job getting the
paper off while leaving the toner on the board.

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Agree.

Initially, I went at the paper in a very tentative way, worried that
any amount of scrubbing would remove the toner. Which is something of
a joke. If you've used enough heat, the toner STAYS, despite scrubbing
with everything that came to hand.

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Not only does this method allow you to make near-perfect reproductions
of data plates and the like, it allows you to etch logos, names and so
forth onto aluminum tool boxes, prepare 'engraved' plates for
presentations, and so on. The tricky bit here is that you are
typically etching in the positive sense rather than the negative. I
found the best way to do this was to make individual masks -- OIL
PRESSURE -- 10 A -- TACHOMETER ...or whatever. The characters
themselves are left clear and the mask is cut to leave a border of
toner. These masks are then ironed on to the panel, plate or whatever
in the usual manner. (Large pieces, such as a tool box or instrument
panel, will benefit from being pre-heated.) Once the masks have been
transferred to the work-piece all of the open areas are sealed with
something that will resist the etchant; regular enamel paint works
okay.

This is a case where acid has a definite advantage, since the object is
to remove a signficant amount of metal.

Once the piece is finished, the etched areas may be filled with a
contrasting paint.

The joke here is that I spent a couple of years making instrument
faces, 'antique' compases and the like before I realized the method
could also be used to make circuit boards :-)

-R.S.Hoover



Would a color copy (negative) transfer the same way? This way you could make labels and placards and then iron them on,
color and all...

..Blueskies. wrote:
snipped
wrote in message oups.com...

RST Engineering wrote:

One of those green kitchen pot scrubbers does a pretty fair job getting the
paper off while leaving the toner on the board.

--------------------------------------------------------------------

Would a color copy (negative) transfer the same way? This way you could make labels and placards and then iron them on,
color and all...



White would be tough on most printers


Sounds like somma you guys have actually tried this technique and
had good results with it. I'm surprised. But it's good news.

I tried it many years ago using a copy machine copy.
Hey, That's all we had!

The results were luke warm at best.
The traces were porous and often had to be "jumped" with wire.
Large ground planes would fade out in the center.
As would any traces running nearby.

No way they were good enough for microprocessor based boards.
That still required a photo shoot to make masks.


Is this trick working better now with a laser printer?



Richard

Richard Lamb wrote:

.Blueskies. wrote:

Would a color copy (negative) transfer the same way? This way you could
make labels and placards and then iron them on, color and all...



White would be tough on most printers



Richard
snip snip etc

How bout high temp (engine/exhaust) paint? Make a mask to paint only where
your transfer will be and pain it white the color copy will handle the
rest. The high temp paint would need to handle the temp of the iron without
discoloring. I haven't tried it but it's an idea! Anyone want to give it a
go and report back? ;-)
John

UltraJohn wrote:
Richard Lamb wrote:


.Blueskies. wrote:

Would a color copy (negative) transfer the same way? This way you could
make labels and placards and then iron them on, color and all...



White would be tough on most printers



Richard

snip snip etc

How bout high temp (engine/exhaust) paint? Make a mask to paint only where
your transfer will be and pain it white the color copy will handle the
rest. The high temp paint would need to handle the temp of the iron without
discoloring. I haven't tried it but it's an idea! Anyone want to give it a
go and report back? ;-)
John


How about a simple step directly to silk screen process?