Homebrew PCBs

Hi all,

I have a few sheets of 90 mil FR-4, (red imprint) that is double 
sided.

I need to do a lot of 1 sided boards and instead of ordering one 
sided, I think I'll just etch one side of these to use the boards.

Anyway, I mechanically etch boards so I need to remove the copper in 
wholesale fashion and have no chemicals to do so.

To make matters worse, the boards are 10 x 18.

What is the simplest, lowest cost method to remove one side of the 
copper ?

Also, I assume something like car or floor wax might make it easy to 
add to the good side as a resist, but suggestions are welcome.


Dave
(I'm in southern NJ if someone wants to trade for some SS 1/16 
material.)

The same here....

It's normally not coming off by peelig from FR4 you will have to etch.

Get yourself some muratic acid and H2O2 and then etch the boards.

I always do chemical etching so it is no problem.

try to heat the board with the heat gun and peel the copper of, maybe it 
works.

ST


On Mon, 22 Mar 2004 06:31:58 -0000, Dave Mucha <dave_mucha@...> 
wrote:

> Hi all,
>
> I have a few sheets of 90 mil FR-4, (red imprint) that is double
> sided.
>
> I need to do a lot of 1 sided boards and instead of ordering one
> sided, I think I'll just etch one side of these to use the boards.
>
> Anyway, I mechanically etch boards so I need to remove the copper in
> wholesale fashion and have no chemicals to do so.
>
> To make matters worse, the boards are 10 x 18.
>
> What is the simplest, lowest cost method to remove one side of the
> copper ?
>
> Also, I assume something like car or floor wax might make it easy to
> add to the good side as a resist, but suggestions are welcome.
>
>
> Dave
> (I'm in southern NJ if someone wants to trade for some SS 1/16
> material.)
>
>
>
>
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
> Yahoo! Groups Links
>
>
>
>
>

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan 
<stefan_trethan@g...> wrote:
> The same here....
> 
> It's normally not coming off by peelig from FR4 you will have to 
etch.
> 
> Get yourself some muratic acid and H2O2 and then etch the boards.
> 
> I always do chemical etching so it is no problem.
> 
> try to heat the board with the heat gun and peel the copper of, 
maybe it 
> works.
> 
> ST


I think I am spoiled,

The first batch of boards I had were of some other substrate and the 
copper pealed off easily.

I can get muriatic acid from the hardware store, so that is easy 
enough.

Hydrogen dioxide... I've seen that on the list before.  Seems I need 
to scan the list for quality and sources.

IIRC, it is not the diluted stuff one buys to put on cuts.

I just check the polls and there is only the poll about a minimum CNC 
machine.

I wonder if we should put together a poll on what method each of us 
use to make boards.


Dave

For the Hydrogen "PER"oxide.
You can get 29% at a local pool/hot tub supply store, It's referred to as
"Shock" and is cheap.
Also a source albeit more expensive, the Wood bleaching kit at Home Depot.
Part B is 30%. Or if you live near a chemical supply location, you might be
able to get some 50%, but this is really not needed for cupric chloride
etchant, 29~30 works just fine.

JT


----- Original Message ----- 

From: "Dave Mucha" <dave_mucha@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, March 22, 2004 7:08 AM
Subject: [Homebrew_PCBs] Re: making one sided boards


> --- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
> <stefan_trethan@g...> wrote:
> > The same here....
> >
> > It's normally not coming off by peelig from FR4 you will have to
> etch.
> >
> > Get yourself some muratic acid and H2O2 and then etch the boards.
> >
> > I always do chemical etching so it is no problem.
> >
> > try to heat the board with the heat gun and peel the copper of,
> maybe it
> > works.
> >
> > ST
>
>
> I think I am spoiled,
>
> The first batch of boards I had were of some other substrate and the
> copper pealed off easily.
>
> I can get muriatic acid from the hardware store, so that is easy
> enough.
>
> Hydrogen dioxide... I've seen that on the list before.  Seems I need
> to scan the list for quality and sources.
>
> IIRC, it is not the diluted stuff one buys to put on cuts.
>
> I just check the polls and there is only the poll about a minimum CNC
> machine.
>
> I wonder if we should put together a poll on what method each of us
> use to make boards.
>
>
> Dave
>
>
>
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
> Yahoo! Groups Links
>
>
>
>
>

Dave,

If you go through the trouble of chemical etching just one side then 
you should do the whole job that way. It wouldn't take much more 
effort to etch the desired image.

If you need dry film photoresist applied to your boards I can do that 
for you. I use a DuPont laminator to apply 1.5 mil photoresist to 
copper clad panels for etching. 

If you coated one side of your two sided material the unwanted side 
will etch clean and the coated side will have the image you want.
This is how we made single sided boards when I owned a commercial 
plant. We always used double sided laminate since it was actually 
cheaper than buying single sided material. One side was imaged and 
then etched to leave them desired image and to remove the unwanted 
side.

If anyone need dry film coated FR-4 or CEM-1 laminate contact me 
direct for more information. This is the same type of photoresist 
that Kepro used to supply.

Tom

--- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" <dave_mucha@y...> 
wrote:
> Hi all,
> 
> I have a few sheets of 90 mil FR-4, (red imprint) that is double 
> sided.
> 
> I need to do a lot of 1 sided boards and instead of ordering one 
> sided, I think I'll just etch one side of these to use the boards.
> 
> Anyway, I mechanically etch boards so I need to remove the copper 
in 
> wholesale fashion and have no chemicals to do so.
> 
> To make matters worse, the boards are 10 x 18.
> 
> What is the simplest, lowest cost method to remove one side of the 
> copper ?
> 
> Also, I assume something like car or floor wax might make it easy 
to 

> add to the good side as a resist, but suggestions are welcome.
> 
> 
> Dave
> (I'm in southern NJ if someone wants to trade for some SS 1/16 
> material.)

> I think I am spoiled,
>
> The first batch of boards I had were of some other substrate and the
> copper pealed off easily.
>
> I can get muriatic acid from the hardware store, so that is easy
> enough.
>
> Hydrogen dioxide... I've seen that on the list before.  Seems I need
> to scan the list for quality and sources.
>
> IIRC, it is not the diluted stuff one buys to put on cuts.
>
> I just check the polls and there is only the poll about a minimum CNC
> machine.
>
> I wonder if we should put together a poll on what method each of us
> use to make boards.
>
>
> Dave


Good idea the poll.

actually you need H2O2 which is dihydrogen dioxide i think, but everybody
calls it hydrogen peroxyde.

I get it from a chemicals shop, very cheap there.
other sources are pool supplys, wood bleaching.

You NEED to find stuff with 30% or 35% concentration.
The pool stuff is about 20% and is the lower limit.

The food/desinfection/hair bleaching stuff is mostly 3% or less,
meaning you need a huge amount.


There are other etchants too, like ferric cloride and such...


Mechanical removal:

I expect the following to work:
take a round rod of steel, heat it, apply solder, apply
solder on one edge of the PCB solder the rod to the copper.
let solidify, then rotate the rod, coiling up the copper like a fish tin 
lid.
Because of the heat from the soldering the glue will already be attacked, 
it will
lift off i think. once you have a piece lifted it should roll off without 
rupture.

I never tried this but from "accidents" when i didn't want it to lift at 
all i expext
it to work.
You can try it and maybe you can aoid the etching alltogether.

ST

> 
> I think I am spoiled,
> 
> The first batch of boards I had were of some other substrate and 
the 
> copper pealed off easily.
> 
> I can get muriatic acid from the hardware store, so that is easy 
> enough.
> 
> Hydrogen dioxide... I've seen that on the list before.  Seems I 
need 
> to scan the list for quality and sources.
> 
> IIRC, it is not the diluted stuff one buys to put on cuts.
> 


I DO use the 3% medical grade. It DOES work. Walmart sells it for 
less than $1 per quart so it's not expensive. Mix it 2 parts H2O2 to 
one part acid (32.25% acording to the bottle). 4 quarts of peroxide 
and 2 quarts of acid make up a gallon and a half and costs about $6. 
$4 per gallon is a LOT cheaper than I can buy Ferric.

For the most part I use a bubbler to rejuvinate it. I wanted a 
bubbler to help speed up the etch anyway, so I just run it for a few 
hours before I need to etch. (usualy I turn it on the night before) 

Works fine for me.
-Denny

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan 
<stefan_trethan@g...> wrote:
> 
> > I think I am spoiled,
> >
> > The first batch of boards I had were of some other substrate and 
the
> > copper pealed off easily.
> >
> > I can get muriatic acid from the hardware store, so that is easy
> > enough.
> >
> > Hydrogen dioxide... I've seen that on the list before.  Seems I 
need
> > to scan the list for quality and sources.
> >
> > IIRC, it is not the diluted stuff one buys to put on cuts.
> >
> > I just check the polls and there is only the poll about a minimum 
CNC
> > machine.
> >
> > I wonder if we should put together a poll on what method each of 
us
> > use to make boards.
> >
> >
> > Dave
> 
> 
> Good idea the poll.
> 
> actually you need H2O2 which is dihydrogen dioxide i think, but 
everybody
> calls it hydrogen peroxyde.
> 
> I get it from a chemicals shop, very cheap there.
> other sources are pool supplys, wood bleaching.
> 
> You NEED to find stuff with 30% or 35% concentration.
> The pool stuff is about 20% and is the lower limit.
> 
> The food/desinfection/hair bleaching stuff is mostly 3% or less,
> meaning you need a huge amount.
> 
> 
> There are other etchants too, like ferric cloride and such...
> 
> 
> Mechanical removal:
> 
> I expect the following to work:
> take a round rod of steel, heat it, apply solder, apply
> solder on one edge of the PCB solder the rod to the copper.
> let solidify, then rotate the rod, coiling up the copper like a 
fish tin 
> lid.
> Because of the heat from the soldering the glue will already be 
attacked, 
> it will
> lift off i think. once you have a piece lifted it should roll off 
without 
> rupture.
> 
> I never tried this but from "accidents" when i didn't want it to 
lift at 
> all i expext
> it to work.
> You can try it and maybe you can aoid the etching alltogether.
> 
> ST



Great idea !

I'l have to try that on a smaller board.

It's nice that this board is so darn thick that it will not bend 
easily.

Dave

Belt sander or equivalent?

Regards,
   JJ

On Tuesday, Mar 23, 2004, at 00:19 US/Eastern, Dave Mucha wrote:

> --- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
> <stefan_trethan@g...> wrote:
>>
>>> I think I am spoiled,
>>>
>>> The first batch of boards I had were of some other substrate and
> the
>>> copper pealed off easily.
>>>
>>> I can get muriatic acid from the hardware store, so that is easy
>>> enough.
>>>
>>> Hydrogen dioxide... I've seen that on the list before.  Seems I
> need
>>> to scan the list for quality and sources.
>>>
>>> IIRC, it is not the diluted stuff one buys to put on cuts.
>>>
>>> I just check the polls and there is only the poll about a minimum
> CNC
>>> machine.
>>>
>>> I wonder if we should put together a poll on what method each of
> us
>>> use to make boards.
>>>
>>>
>>> Dave
>>
>>
>> Good idea the poll.
>>
>> actually you need H2O2 which is dihydrogen dioxide i think, but
> everybody
>> calls it hydrogen peroxyde.
>>
>> I get it from a chemicals shop, very cheap there.
>> other sources are pool supplys, wood bleaching.
>>
>> You NEED to find stuff with 30% or 35% concentration.
>> The pool stuff is about 20% and is the lower limit.
>>
>> The food/desinfection/hair bleaching stuff is mostly 3% or less,
>> meaning you need a huge amount.
>>
>>
>> There are other etchants too, like ferric cloride and such...
>>
>>
>> Mechanical removal:
>>
>> I expect the following to work:
>> take a round rod of steel, heat it, apply solder, apply
>> solder on one edge of the PCB solder the rod to the copper.
>> let solidify, then rotate the rod, coiling up the copper like a
> fish tin
>> lid.
>> Because of the heat from the soldering the glue will already be
> attacked,
>> it will
>> lift off i think. once you have a piece lifted it should roll off
> without
>> rupture.
>>
>> I never tried this but from "accidents" when i didn't want it to
> lift at
>> all i expext
>> it to work.
>> You can try it and maybe you can aoid the etching alltogether.
>>
>> ST
>
>
>
> Great idea !
>
> I'l have to try that on a smaller board.
>
> It's nice that this board is so darn thick that it will not bend
> easily.
>
> Dave
>
>
>
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
> Yahoo! Groups Links
>
>
>
>
>

--- In Homebrew_PCBs@yahoogroups.com, John Johnson <johnatl@m...> 
wrote:
> Belt sander or equivalent?
> 
> Regards,
>    JJ


Could work.  Maybe just put a rope on it and a box and drage it down 
the street.

Since this is a really thick board, it could work !

But, I'm off to the store to buy some acid and hydrogen peroxide.


Dave

In Homebrew_PCBs, Stefan Trethan <stefan_trethan@g...> wrote:
> Get yourself some muratic acid and H2O2 and then etch the boards.


This is new to me. Is there a reason it doesn't get mentioned more 
often? We talk about FECL and the two persulphates... But not this.

What are it's good and bad points? Besides being really cheap and 
widely available<G>

Thank you in advance,

Ballendo

On Tue, 23 Mar 2004 17:29:29 -0000, ballendo <ballendo@...> wrote:

> In Homebrew_PCBs, Stefan Trethan <stefan_trethan@g...> wrote:
>> Get yourself some muratic acid and H2O2 and then etch the boards.
>
>
> This is new to me. Is there a reason it doesn't get mentioned more
> often? We talk about FECL and the two persulphates... But not this.
>
> What are it's good and bad points? Besides being really cheap and
> widely available<G>
>
> Thank you in advance,
>
> Ballendo
>

good points:
it doesn't get used up. you never throw it away.
it slowly grows over time, nothing else.
You only replenish HCl and H2O2 as needed and that's it.

I have no time now, there is a huge amount of information
(look in the links section).
also in the archives others and i have explained a dozen times.

Read, and if you have questions i will answer them tomorrow.

ST

This is actually cupric chloride etching. Once you have the etchant 
started you don't even need the H2O2. Just bubbling air though it for a 
couple of hours does the trick. Do a google search for cupric chloride 
etchant.

I use it and it works well. It does not stain like FeCl and doesn't 
smell as bad either. The down sides are that it takes slightly longer to 
etch and the etchant will only do a couple of boards before it needs 
regenerating by bubbling air through it or adding H2O2.

Les


ballendo wrote:

> In Homebrew_PCBs, Stefan Trethan <stefan_trethan@g...> wrote:
> 
>>Get yourself some muratic acid and H2O2 and then etch the boards.
> 
> 
> 
> This is new to me. Is there a reason it doesn't get mentioned more 
> often? We talk about FECL and the two persulphates... But not this.
> 
> What are it's good and bad points? Besides being really cheap and 
> widely available<G>
> 
> Thank you in advance,
> 
> Ballendo
> 
> 
> 
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs 
> Yahoo! Groups Links
> 
> 
> 
>  
> 
>

It's bad points,

Chlorine smell.
Chlorine Gas release if improperly cared for
Slower etching time
Etches nearly all metals, and concrete , fumes can corrode nearby metals.

But imo if properly cared for, and proper steps taken to setup your work
area, ventilation good, etc...
It's good points out weigh it's bad points.

JT
----- Original Message ----- 

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, March 23, 2004 12:47 PM
Subject: Re: [Homebrew_PCBs] muriatic and H2O2 -goods and bads ?


> On Tue, 23 Mar 2004 17:29:29 -0000, ballendo <ballendo@...> wrote:
>
> > In Homebrew_PCBs, Stefan Trethan <stefan_trethan@g...> wrote:
> >> Get yourself some muratic acid and H2O2 and then etch the boards.
> >
> >
> > This is new to me. Is there a reason it doesn't get mentioned more
> > often? We talk about FECL and the two persulphates... But not this.
> >
> > What are it's good and bad points? Besides being really cheap and
> > widely available<G>
> >
> > Thank you in advance,
> >
> > Ballendo
> >
>
> good points:
> it doesn't get used up. you never throw it away.
> it slowly grows over time, nothing else.
> You only replenish HCl and H2O2 as needed and that's it.
>
> I have no time now, there is a huge amount of information
> (look in the links section).
> also in the archives others and i have explained a dozen times.
>
> Read, and if you have questions i will answer them tomorrow.
>
> ST
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
> Yahoo! Groups Links
>
>
>
>
>

On Tue, 23 Mar 2004 13:50:16 -0500, Jeremy Taylor <jt@...> wrote:

> It's bad points,
>
> Chlorine smell.
> Chlorine Gas release if improperly cared for
> Slower etching time
> Etches nearly all metals, and concrete , fumes can corrode nearby metals.
>
> But imo if properly cared for, and proper steps taken to setup your work
> area, ventilation good, etc...
> It's good points out weigh it's bad points.
>
> JT


If you keep the lid on there are no corrosion problems.
Just don't let a jar of it standing around until all is vaporized near 
tools.


Etching time is a question of H2O2 concentration also. if it is OK it is 
much faster
than only with using bubbling. I do not know exactly why. Of course
clorine production will increase. But if you have some ventilation you can 
have a board in
11 seconds ;-).

 From my past experience with FeCl it is not slower, with a nearly zero 
level of clorine.
with some clorine it can be much faster. and the clorine smell is still
lower than what you get from any swimmingpool that uses clorine in it's 
filter.

(Meaning the smell around the filter unit, not the water itself)

ST

Les,

So the "cupric" part is coming from the 1st board being etched?

I looked at the links section as suggested. Had seen all that before. 
(I remember thinking too much work compared to just buying the 
persulphate, and it was dark like FeCl.)

What prompted my interest in this thread was the muriatic is clear, 
and the h202 is clear, (no mention of cupric at all) so I thought it 
was a clear process... Now I'm confused.

If I use mostly HCL and a bit of H202, and put my board in, will it 
etch well? Will it stay clear?

From what you've written above, I would think that the h202 is just a 
means to get oxygen into the HCL, so a bubbler/sparger and HCL is the 
ticket? (with the usual concerns about muriatic vapors)

Thank you in advance for any clarification,

Ballendo


--- In Homebrew_PCBs@yahoogroups.com, Les Newell <les@l...> wrote:
> This is actually cupric chloride etching. Once you have the etchant 
> started you don't even need the H2O2. Just bubbling air though it 
for a 
> couple of hours does the trick. Do a google search for cupric 
chloride 
> etchant.
> 
> I use it and it works well. It does not stain like FeCl and doesn't 
> smell as bad either. The down sides are that it takes slightly 
longer to 
> etch and the etchant will only do a couple of boards before it 
needs 
> regenerating by bubbling air through it or adding H2O2.
> 
> Les
> 
> 
> ballendo wrote:
> > In Homebrew_PCBs, Stefan Trethan <stefan_trethan@g...> wrote:
> > 
> >>Get yourself some muratic acid and H2O2 and then etch the boards.
> > 
> > 
> > 
> > This is new to me. Is there a reason it doesn't get mentioned 
more 
> > often? We talk about FECL and the two persulphates... But not 
this.
> > 
> > What are it's good and bad points? Besides being really cheap and 
> > widely available<G>
> > 
> > Thank you in advance,
> > 
> > Ballendo
> > 
> > 
> > 
> > Be sure to visit the group home and check for new Bookmarks and 
files:

> > http://groups.yahoo.com/group/Homebrew_PCBs 
> > Yahoo! Groups Links
> > 
> > 
> > 
> >  
> > 
> >

it turns green, and gets less transparent as it fills with copper. If it
gets saturated it actually will turn blue.


The first few board will be very slow. You can add more h202 to speed it up,
but this can cause some gassing.
my advice, get it nice and warm, and be patient. It does get faster as it
matures.

----- Original Message ----- 

From: "ballendo" <ballendo@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, March 23, 2004 5:43 PM
Subject: [Homebrew_PCBs] Re: muriatic and H2O2 -goods and bads ?


> Les,
>
> So the "cupric" part is coming from the 1st board being etched?
>
> I looked at the links section as suggested. Had seen all that before.
> (I remember thinking too much work compared to just buying the
> persulphate, and it was dark like FeCl.)
>
> What prompted my interest in this thread was the muriatic is clear,
> and the h202 is clear, (no mention of cupric at all) so I thought it
> was a clear process... Now I'm confused.
>
> If I use mostly HCL and a bit of H202, and put my board in, will it
> etch well? Will it stay clear?
>
> From what you've written above, I would think that the h202 is just a
> means to get oxygen into the HCL, so a bubbler/sparger and HCL is the
> ticket? (with the usual concerns about muriatic vapors)
>
> Thank you in advance for any clarification,
>
> Ballendo
>
>
> --- In Homebrew_PCBs@yahoogroups.com, Les Newell <les@l...> wrote:
> > This is actually cupric chloride etching. Once you have the etchant
> > started you don't even need the H2O2. Just bubbling air though it
> for a
> > couple of hours does the trick. Do a google search for cupric
> chloride
> > etchant.
> >
> > I use it and it works well. It does not stain like FeCl and doesn't
> > smell as bad either. The down sides are that it takes slightly
> longer to
> > etch and the etchant will only do a couple of boards before it
> needs
> > regenerating by bubbling air through it or adding H2O2.
> >
> > Les
> >
> >
> > ballendo wrote:
> > > In Homebrew_PCBs, Stefan Trethan <stefan_trethan@g...> wrote:
> > >
> > >>Get yourself some muratic acid and H2O2 and then etch the boards.
> > >
> > >
> > >
> > > This is new to me. Is there a reason it doesn't get mentioned
> more
> > > often? We talk about FECL and the two persulphates... But not
> this.
> > >
> > > What are it's good and bad points? Besides being really cheap and
> > > widely available<G>
> > >
> > > Thank you in advance,
> > >
> > > Ballendo
> > >
> > >
> > >
> > > Be sure to visit the group home and check for new Bookmarks and
> files:
> > > http://groups.yahoo.com/group/Homebrew_PCBs
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
>
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
> Yahoo! Groups Links
>
>
>
>
>

>
> From what you've written above, I would think that the h202 is just a
> means to get oxygen into the HCL, so a bubbler/sparger and HCL is the
> ticket? (with the usual concerns about muriatic vapors)
>
> Thank you in advance for any clarification,
>
> Ballendo
>

Yes it works with only a bubbler.
However it is much easier and faster to use H2O2. it is so cheap i do not 
really care.
Also i want no fumes from the bubbler because i store it in a room with 
loads of tools and i
do not want corrosion (the bubbler has to run long times to get enough air 
in).

It stays clear enough to see the board through it.

I also noticed that with a little bit of excess H2O2 the etching itself is 
faster (maybe
the Cu2Cl2 is instantly reduced back to CuCl2 by the excess H2O2, i do not 
know.)


H2O2 is a very easy, clean way to get the oxygen in. 100% H2O2 has about 
1,4kg that means
there is half a kg oxygen solved in there, or not?

O weighs 22g/mol, so .4 kg is 18 mol. (it is only 35% H2O2 so let us 
calculate with 6mol

Cu weighs ? 60g/mol, so with the above O you could theoretically convert 
360g copper.
it weighs 9g/ccm which means that are 40ccm and with 35u copper thickness 
that are 1,1 square
meter with one bottle H2O2 35%..

would be 62 100mmx160mm single sided.

Not sure if this calculation makes any sense at all..

ST