I actually found my unopened bottle of Ferric Chloride from Radio Shack yesterday. So if I am unhappy with my other method I am using I can try the sponge trick.

Thanks

On 3/5/2019 3:49 AM, Fast Eddie wrote:

It's been awhile, but what I learned from using the acid-H2O2 mix is that time is of the essence...the longer the board sits in the etchant, the more the etchant starts eating away at the unprotected sides of the copper traces that you are trying to preserve, so if you have very narrow traces closely spaced they can end up being thinner than desired. Eventually I changed my technique from using the acid-H2O2 bath to using about a teaspoon or two of ferric chloride and a small piece of a car wash sponge and scrubbing the board to etch it. I found that I could etch a board in less time with less circuit trace erosion as well as focus the etching on those slower to etch areas. I used very little ferric chloride in the process so i had next to nothing to dispose of as well. Of course, there are pluses and minuses in every method you use, but this one worked the best for me. I used to get the FeCl3 from Radio Shack it was that long ago. If you aren't happy with your results you might think about giving that method a try...like I say, it worked well for me.

i do warm the etchant to 80deg Celsius in a boil water under tank. It makes my work faster.

On Tue, Mar 5, 2019 at 4:56 PM MVS Sarma via Groups.Io <mvssarma=[email protected]> wrote:

Ferric chloride disposal is a a cumber some affair.

?Most Indian PCB makers appear to be using HCL and h2o2.

Ammonium per oxide, i bought a bottle, but never used.

Till now only Ferric chloride . Working OK? for me for my hobby use.

On Tue, Mar 5, 2019 at 3:19 PM Fast Eddie <epinnell@...> wrote:

It's been awhile, but what I learned from using the acid-H2O2 mix is that time is of the essence...the longer the board sits in the etchant, the more the etchant starts eating away at the unprotected sides of the copper traces that you are trying to preserve, so if you have very narrow traces closely spaced they can end up being thinner than desired. Eventually I changed my technique from using the acid-H2O2 bath to using about a teaspoon or two of ferric chloride and a small piece of a car wash sponge and scrubbing the board to etch it. I found that I could etch a board in less time with less circuit trace erosion as well as focus the etching on those slower to etch areas. I used very little ferric chloride in the process so i had next to nothing to dispose of as well. Of course, there are pluses and minuses in every method you use, but this one worked the best for me. I used to get the FeCl3 from Radio Shack it was that long ago. If you aren't happy with your results you might think about giving that method a try...like I say, it worked well for me.

_._,_._,_

On 05/03/19 22:26, MVS Sarma wrote:

Ferric chloride disposal is a a cumber some affair.
??Most Indian PCB makers appear to be using HCL and h2o2.

Ammonium per oxide, i bought a bottle, but never used.
Till now only Ferric chloride . Working OK? for me for my hobby use.

There is no need to *ever* dispose of Ferric chloride.

Start with it diluted 1:1 with water, and just add some HCl every time you use it. Keep the Ferric chloride covered when not in use.

Use air bubble agitation, because the dissolved oxygen regenerates it.

Ferric chloride disposal is a a cumber some affair.

?Most Indian PCB makers appear to be using HCL and h2o2.

Ammonium per oxide, i bought a bottle, but never used.

Till now only Ferric chloride . Working OK? for me for my hobby use.

On Tue, Mar 5, 2019 at 3:19 PM Fast Eddie <epinnell@...> wrote:

It's been awhile, but what I learned from using the acid-H2O2 mix is that time is of the essence...the longer the board sits in the etchant, the more the etchant starts eating away at the unprotected sides of the copper traces that you are trying to preserve, so if you have very narrow traces closely spaced they can end up being thinner than desired. Eventually I changed my technique from using the acid-H2O2 bath to using about a teaspoon or two of ferric chloride and a small piece of a car wash sponge and scrubbing the board to etch it. I found that I could etch a board in less time with less circuit trace erosion as well as focus the etching on those slower to etch areas. I used very little ferric chloride in the process so i had next to nothing to dispose of as well. Of course, there are pluses and minuses in every method you use, but this one worked the best for me. I used to get the FeCl3 from Radio Shack it was that long ago. If you aren't happy with your results you might think about giving that method a try...like I say, it worked well for me.

_._,_._,_

---

On Mon, 4 Mar 2019 17:39:37 -0600, you wrote:

Harvey,

? Yes, all good info. My Proxxon just arrived so I will been opening
the little box and see what I bought. :)? I figure 8500 rpms will be
fine and being it's a hobby I will be ok. I have a large milling machine
and learned a lot from using it. Too bad it isn't CNC. :)

One of these days, I'll complete the CNC conversion on my X1...

Harvey

On Mon, 4 Mar 2019 16:46:21 -0600, you wrote:

Harvey,

? I am a very careful person but I do appreciate the warnings
nonetheless. How thick is the correct amount of plating?

Not very, I think it works out to (and check the MG chemicals website)
5 microinches/minute. I remember leaving the boards in for about 5-6
minutes, which is what they recommend.

I used old photo trays, 5x7 or 8x10 were fine, and the plastic was not
attacked by the chemicals. You'll want a dedicated funnel for the
bottle, too.

While the solution has "brighteners" in it, that remove airborne
induced oxidation, the cleaner you get often the better.

When I did double sided boards, I could not have any vias under a part
(except a dip socket), but had to place them outside of any part.

I used #26 wire to "lace" the top to the bottom at the vias, soldered
both sides, then carefully clipped the excess off.

I also made the top and bottom separate, and aligned them (it can get
tricky) and used 30 minute (not 5, think about it....) epoxy to put
the boards together, and fairly stiff pins to align them. I had
masking tape on both copper sides (keeps epoxy fingerprints off...),
used gloves, and used tape to hold the boards in alignment before I
put the sides together. Putting it between two slabs of marble (home
discount store cheap stuff), made the whole board turn out flat.

Once done, remove the tape, trim to size (I use a shear), and then
drill.

Better to use a vacuum cleaner sucking in the debris than blowing
fiberglass dust into the air.

If you can find someone with a CPAP unit, the old hoses can be useful.

Harvey

On 3/4/2019 3:25 PM, Harvey White wrote:

On Mon, 4 Mar 2019 13:38:34 -0600, you wrote:

Please read the warning labels, do this outside, and do not breathe
the fumes.

Time in bath equates to thickness of plating.

Solution can be reused many times until it fails.

Harvey

It's been awhile, but what I learned from using the acid-H2O2 mix is that time is of the essence...the longer the board sits in the etchant, the more the etchant starts eating away at the unprotected sides of the copper traces that you are trying to preserve, so if you have very narrow traces closely spaced they can end up being thinner than desired. Eventually I changed my technique from using the acid-H2O2 bath to using about a teaspoon or two of ferric chloride and a small piece of a car wash sponge and scrubbing the board to etch it. I found that I could etch a board in less time with less circuit trace erosion as well as focus the etching on those slower to etch areas. I used very little ferric chloride in the process so i had next to nothing to dispose of as well. Of course, there are pluses and minuses in every method you use, but this one worked the best for me. I used to get the FeCl3 from Radio Shack it was that long ago. If you aren't happy with your results you might think about giving that method a try...like I say, it worked well for me.

_._,_._,_

---

Received from Harvey White at 3/5/2019 01:13 AM UTC:

When you do the etching, you'll want a bubbler of some sort.? The HCL/H2O2 etchant works very well until you run out of H2O2, perhaps 30 days.

Use the same bubbler you use to agitate the solution when etching to rejuvenate the solution when it gets to the point that it is no longer a nice emerald green. It will turn emerald green after a number of etchings due to dissolved copper. It's starting to become spent when it starts turning brownish. That's the time to bubble air thru it 24/7 until it's emerald green again. When you find you can't rejuvenate it by bubbling air thru it, add a bit of HCl. No need to add H2O2 if you rejuvenate by bubbling air thru it... which has the advantage of not diluting the solution since drugstore H2O2 is about 94 - 97% water. Rejuvenating by bubbling isn't a fast process, but you'll have to etch a heck of a lot of boards to fall behind.

Make note of the liquid level before an extended bubbling session and dilute it back up to replace evaporated water if you see that the level has dropped.

Jim H

On Mon, 4 Mar 2019 16:43:20 -0600, you wrote:

Ok on the top/bottom posting. Nobody is complaining yet. :)

My default trace setting was 15 and I had bumped it up to 20 so that
sounds good to me. I have seen those "islands" you speak of and figured
it was either a ground plane or a way to save etching time. I may
experiment with that.

The island approach really didn't require etching, it needed an xacto
knife and a ruler.

Etching time will be the same, as long as you have enough etchant.
Think about that one, you have to go through the same amount of copper
regardless. When you do the etching, you'll want a bubbler of some
sort. The HCL/H2O2 etchant works very well until you run out of H2O2,
perhaps 30 days. The etchant then changes (slowly) into CuCl etchant,
which etchs when oxygen is added, literally, your first time look at
the copper and you'll see it turning reddish and going away, that's
the copper oxidizing in solution.

Once the etchant changes color, then you're likely in CuCl etching.
I'm not the expert, but an internet search may give you accurate (and
better than mine) details.

For the mechanical approach, you could also use CNC and some sort of
router bit (usually PCB and carbide). It works very well on discrete
transistors/resistors/capacitors but has a limited utility when
dealing with ICs... Has more to do with pin spacing than not.

Main thing is that you make boards that work for you. As you decide
to go from through hole to surface mount, and then to TFQP flatpacks,
and then plated through holes, your techniques will change until you
likely need to use a board house to make the designs. Mine did.

However, there's a lot you can learn in the process.

Harvey

I am using DesignSparkPCB for now.

I ordered the 16oz bottle of MG Liquid Tin. That should last me forever.
Good reasoning on why a lot of people don't use Tinit or Liquid Tin
because they finish soldering all the components right away. Now I can
plan ahead and etch, tin, and save for later finishing if need be.

Thanks


On 3/4/2019 1:45 PM, Harvey White wrote:

On Mon, 4 Mar 2019 11:31:38 -0600, you wrote:

Quick question. Is top posting preferred here. That is the way I like to
do it but on some other forums people complain and like it the other way.

I prefer to interleave where reasonable. For this post, I will. For
the previous post, it was so long that without seriously trimming it,
my reply would be at the very bottom.

You get your choice, I think.

Now back to the subject at hand...All good info but, if I am just
starting out and am not worried about trace widths, my job should be
easier if I use wide traces at first, right? I remember taking apart old
electronics and the traces and solder were absolutely thick. And for
starters my projects will be very simple, like a breakout board.

Generally about 16 mils is what I normally use. However, as long as
the traces work for you, and you can build the board, it doesn't
matter.

There's a method that makes the pads as large as possible, so you're
wiring parts between very large pads, islands, even. The 1/16 inch or
so is the space around the pads. Saves etchant and can be done with
an xacto knife in some cases.

I think I seen where Rob found that Krylon enamel paint was a great
resist that could be thinned with lacquer thinner and used in a pen.

Depends on how you do the board. I generally did a program (like
EAGLE), toner transfer, and then I tinned the board.

Does Tinit help any or is that just a corrosion preventative and does
anyone use it anymore?

It's a bit of a corrosion inhibitor, and is effectively solder, so it
makes soldering easier.

I've done boards both ways, and if you build the board all at once,
then you likely can get away without the tin/lead. What happens if
you don't is that you get tarnish from normal oxidation and soldering
becomes difficult.

If you could mask the pads somehow, you could do a solder mask with
paing, and that would allow you to have a neater board. That, with a
silk screen layer would be a good look.

What they do in the factory is use a solder mask chemical that's UV
cureable... The stencil has holes where the pads are, you coat the
entire board with the mask, let it dry, and then the UV through the
stencil destroys the polymer so that the exposed areas wash off,
uncovering the pads.

Hence the tinning that tends to make the board look good and reduces
corrosion.

Harvey

On 06/03/19 01:09, Dave wrote:

So I want to build a bubble tank. Anybody have any best methods or DIY plans? I am pretty sure my boards will remain small for the foreseeable future so I don't think I need an aquarium. :) I assume plastic is the best after glass and likely no metal parts touching the solution. An aquarium pump should work, proven designs are what I am after.