Slightly OT?: CuCl PCB heater & bubbler

[Mark Jones]

I was wondering, if one were using a typical aquarium-style heater in
a cupric-chloride etching tank, could the bubbler be placed underneath
the heater during operation? (Would the "cool" bubbles cause any
problem with the "hot" heater?)

Furthermore, did I read somewhere that PCB's should not be bubbled in
CuCl etchant?

Thanks.

 

[Nico Coesel]

Mark Jones <abuse@127.0.0.1> wrote:

I was wondering, if one were using a typical aquarium-style heater in
a cupric-chloride etching tank, could the bubbler be placed underneath
the heater during operation? (Would the "cool" bubbles cause any
problem with the "hot" heater?)

Furthermore, did I read somewhere that PCB's should not be bubbled in
CuCl etchant?

AFAIK:
Etching with CuCl is not something to be done at home. The process
requires constant balancing of the chemicals. It is a very good
production process and environmentally friendly (the etchant is
constantly recycled).

Aren't you referring to ferric chloride (FeCl)?

Anyway, I don't think placing the bubbler underneatch the heaters is a
problem. Depending on the size of you tank you may need quite big
heaters though. My tank needed 2 300W heaters to get 12 liters (small
miscalculation) of etchant warm in 20 minutes.

--
Reply to nico@nctdevpuntnl (punt=.)
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[Dmitri(Cabling-Design.com]

Mark Jones wrote:

I was wondering, if one were using a typical aquarium-style heater in
a cupric-chloride etching tank, could the bubbler be placed underneath
the heater during operation? (Would the "cool" bubbles cause
any
problem with the "hot" heater?)

Furthermore, did I read somewhere that PCB's should not be bubbled in
CuCl etchant?

Thanks.

I would assume you are talking about FeCl (Radio Shack stuff ;-) )

The aquarium bubble stone will work for awhile, but is not reliable (at
least to me). Just make sure you cover the container: the bubbles produce
VERY nasty mist. You don't want it to get on anything around the tank.

There is a newsgroup that's more narrowly focuses on PCBs and related
stuff: sci.electronics.cad We keep its Web interface here:
http://www.cabling-design.com/forums/newsgroup45-.htm
You may want to try your question there as well.

--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
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[xray]

On Mon, 10 Jan 2005 22:26:29 -0500, Mark Jones <abuse@127.0.0.1> wrote:

For the bubbler I was thinking of a length of polypropylene tubing
with many fine holes drilled in it.

In the one I built, I went to the aquarium supply store and found some
stuff designed for bubbling. Its some kind of porous plastic tubing
about .25 in dia. I think it is meant for burying under gravel in a fish
tank. In the bubbler, I ran several rows of it in parallel about 1 in
apart. Needs a strong pump to feed it all.

It seems to survive in the etchant ok.

 

[Mark Jones]

xray wrote:

On Mon, 10 Jan 2005 23:18:13 -0500, Mark Jones <abuse@127.0.0.1> wrote:


I saw a design on the web where someone converted a plastic cooler
(ice chest) into a CuCl etching tank. (Heaven forbid anyone thinking
there were party punch in there!) The website is gone, but you can
still see thumbnails if you google for images called "CuCl etching".


Yes, that was probably my web page. I copied that stuff from a book
published in 1983, but I did get permission from the author.

I have used it to etch with a bubbler. It worked but seemed slower than
FeCl. I still have all the stuff, but haven't found the reason to use it
lately. In theory, you can rejuvenate the solution just by bubbling air
through it (to add O2) but in emails with the author, he says he now
uses strong hydrogen peroxide. You also need to add HCl and water either
way.

Oh cool. From what I've found, it looks like the optimum temperature
for Cu++Cl2 etchant is 130 degrees F. Were you using a heater? (Could
an ice chest withstand a heater?)

H2O2 would be an ideal rejuvinator. That extra oxygen atom would
really do the trick. It seems like nearly all reactions involving CuCl
produce H20 - with the addition of H2O2 doesn't the solution end up
being "watered down?"

This fall I etched a board outside using FeCl... it took nearly 50
minutes with no heater. I even put a lamp over it, but it still
undercut noticably. I used a ziplock baggie so no yellow finger
syndrome and poured the used etchant back into the bottle. Eventually
it will have to be disposed of. I've learned that if you neutralize
FeCl etchant with sodium hydroxide, it produces NaCl and Fe3(OH)2,
which can be burned (reduced) to rust and hydrogen gas. This is still
a big hassle, and one reason CuCl is looking so interesting.

I got myself a web domain and a place to resurrect my pages, but after
dumping my old ISP, I have been lazy about putting up pages. I want to
redo them using CSS but I haven't found a style I like yet. When I get
it finished, I'll post a message here with CuCl in the subject, and give
a link.

Great, thanks. Eventually I'll put my design up on the web also. It's
gonna take awhile though.

Oh, and for CSS perhaps you'd like
http://www.westciv.com/style_master/ - they have a demo, very handy
for rapid CSS design.

Regards,
Mark Jones


-- "If necessity is the mother of invention, then is experimentation
the father?" MCJ 20041116

 

[Nico Coesel]

Mark Jones <abuse@127.0.0.1> wrote:

xray wrote:
On Mon, 10 Jan 2005 23:18:13 -0500, Mark Jones <abuse@127.0.0.1> wrote:


I saw a design on the web where someone converted a plastic cooler
(ice chest) into a CuCl etching tank. (Heaven forbid anyone thinking
there were party punch in there!) The website is gone, but you can
still see thumbnails if you google for images called "CuCl etching".


Yes, that was probably my web page. I copied that stuff from a book
published in 1983, but I did get permission from the author.

I have used it to etch with a bubbler. It worked but seemed slower than
FeCl. I still have all the stuff, but haven't found the reason to use it
lately. In theory, you can rejuvenate the solution just by bubbling air
through it (to add O2) but in emails with the author, he says he now
uses strong hydrogen peroxide. You also need to add HCl and water either
way.


Oh cool. From what I've found, it looks like the optimum temperature
for Cu++Cl2 etchant is 130 degrees F. Were you using a heater? (Could
an ice chest withstand a heater?)

H2O2 would be an ideal rejuvinator. That extra oxygen atom would
really do the trick. It seems like nearly all reactions involving CuCl
produce H20 - with the addition of H2O2 doesn't the solution end up
being "watered down?"

This fall I etched a board outside using FeCl... it took nearly 50
minutes with no heater. I even put a lamp over it, but it still

You'll need at least a heater and a pump. The best way to use FeCl is
in a spray etching machine though. Etching times of 5 minutes or less
are achievable.

undercut noticably. I used a ziplock baggie so no yellow finger
syndrome and poured the used etchant back into the bottle. Eventually
it will have to be disposed of. I've learned that if you neutralize
FeCl etchant with sodium hydroxide, it produces NaCl and Fe3(OH)2,
which can be burned (reduced) to rust and hydrogen gas. This is still
a big hassle, and one reason CuCl is looking so interesting.

You don't need to dispose FeCl. It can be regenerated with
Hydrochloric acid (HCl). 10% HCl is available in a lot of stores.
Don't worry about the extra water, you'll need it to compensate for
loss of fluid due to evaporation.

I have been using the same FeCl for about 12 years (or more) now.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl

 

[Nico Coesel]

John Woodgate <jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Nico Coesel <nico@puntnl.niks
wrote (in <41e44a53.1933829730@news.planet.nl&gt about 'Slightly OT?:
CuCl PCB heater & bubbler', on Tue, 11 Jan 2005:
You don't need to dispose FeCl. It can be regenerated with Hydrochloric
acid (HCl). 10% HCl is available in a lot of stores. Don't worry about
the extra water, you'll need it to compensate for loss of fluid due to
evaporation.

I have been using the same FeCl for about 12 years (or more) now.

How do you get rid of the dissolved copper? If you don't, you may
actually be using CuCl2 as the etchant without knowing it!

I know, but it is not quite the same. When the solution is
regenerated, a mix from FeCl and CuCl is doing the etching (if I
remember correctly from my etching bible).

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl

 

[xray]

On Tue, 11 Jan 2005 16:05:57 -0500, Mark Jones <abuse@127.0.0.1> wrote:

Oh cool. From what I've found, it looks like the optimum temperature
for Cu++Cl2 etchant is 130 degrees F. Were you using a heater? (Could
an ice chest withstand a heater?)

H2O2 would be an ideal rejuvinator. That extra oxygen atom would
really do the trick. It seems like nearly all reactions involving CuCl
produce H20 - with the addition of H2O2 doesn't the solution end up
being "watered down?"

I took a fish tank heater -- adjusted to some hottish temp (I can't
remember the details) and replanted it in a large test tube with
chemistry rubber stopper and tight sealing enforced for wires and all
junctions with some kind of "glue" - might have been silicone. I think I
sealed it hot to minimize expansion pressure.

With the tight sealing, I got the whole heater horizontal at the bottom
of the tank. The cooler container has survived so far - only a few
attempts really, but I don't see problems from the heat.

On the rejuvenating -- the original article (none of it my work-I just
provided what I found interesting) has the details. It is not simple.
You need to monitor both specific gravity and the acid level, by
titration.

I accumulated enough chemical supplies and kludgy apparatus to get it
done. It is not simple. I doubt if a dash of this or that each time
would suffice very long.

On the FeCl side, the original author of my method offered one of the
best sounding suggestions I ever heard for disposing of spent FeCl
solution -- Use it to mix with cement (concrete). Send the resulting
brick to the dump. Any bad stuff should be tied pretty tightly inside
this brick. Way better than pouring down the drain or somewhere else.

All these methods have potential negatives. It was mentioned earlier
that either solution in a bubbler creates corrosive or staining spray if
not carefully contained or cleaned. The HCl in in the CuCl will creap
out and attack nearby metals if not tightly sealed, even just sitting
there.

I'm no real expert on any of this, but I have tried it.