Homebrew_PCBs

For some reason this didn't get posted last week, my apologies if it shows
up twice, but I'm making boards on Wednesday, and would like some input.

In my Kepro datasheet, it says I can shock the solution by adding some spent
Sodium Persulfate so I don't have to wait for it to stabilize.

I had some used solution which was 3 months old that I used to shock the
bath. I know the shelf life for etching is 3 weeks, but can it still be used
to add in adjusting the pH? The experience as shown below seemed to indicate
its not possible, but I want to know if I need to look at some other reason
for the slow etch rate.

I went ahead and etched, but it took forever. I was successful at 12/12, but
the etching seem to take 15 - 20 minutes. When I had my techs making proto
boards, it seemed we could etch in 2-4 minutes. The solution was at 105-110
deg F. The board was quite small, and as I use huge ground planes and leave
dead copper on the board to reduce waste, It seems it should have etched
close to the 2 minute time frame rather than 20 minutes.

I doing tray etching with manual agitation.

Thanks
Ron

I use ammonium persulfate which I think behaves almost identical to
sodium persulfate, I have read there are some subtle differences with
etching between the two. I have never heard of needing to "shock" the
solution. What is the purpose of "shocking" ?

I've read that iron ions and some other metal contaminants can
accelerate the decomposition of persulfate. The pH of persulfate
etchants are always acidic (very low pH) because of the decomposition
products ,

2H20 + S208(2-) -> 2H(+) + 2S04(2-) + H2O2

You basically get sulfuric acid and peroxide which then further
decomposes to release oxygen. Heat also speeds decomposition. I've got
some solution for 2 years that I occasionally use for very light
etching. The fact I've never heating the solution could be why its
still showing some strength.
A common method of completely destroy persulfate is to boil them in
solution for ten minutes or so.
You can switch to ferric chloride if you want an indefinite shelf
life. Just put it in a etching tank so you never have to let the stuff
touch anything else but the PCB.
Recommended startup concentration for persulfate is 200g/liter of the
salt.

Ron Amundson wrote:

> For some reason this didn't get posted last week, my apologies if it shows
> up twice, but I'm making boards on Wednesday, and would like some input.
>
> In my Kepro datasheet, it says I can shock the solution by adding some spent
> Sodium Persulfate so I don't have to wait for it to stabilize.
>
> I had some used solution which was 3 months old that I used to shock the
> bath. I know the shelf life for etching is 3 weeks, but can it still be used
> to add in adjusting the pH? The experience as shown below seemed to indicate
> its not possible, but I want to know if I need to look at some other reason
> for the slow etch rate.
>
> I went ahead and etched, but it took forever. I was successful at 12/12, but
> the etching seem to take 15 - 20 minutes. When I had my techs making proto
> boards, it seemed we could etch in 2-4 minutes. The solution was at 105-110
> deg F. The board was quite small, and as I use huge ground planes and leave
> dead copper on the board to reduce waste, It seems it should have etched
> close to the 2 minute time frame rather than 20 minutes.
>
> I doing tray etching with manual agitation.
>
> Thanks
> Ron
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

I need to dig up the data sheet for a better explanation, and I'll post it
later.

I am howver interested in your findings with ferric chloride. I've got some
around here as well, and as you stated its shelf life is a real advantage. I
however have never been able to acheive decent etching with it. I've tried
room temperature, 50 deg C (122 deg F), agitation and aeration, and have
always had problems with non-uniform etching. Part of the board gets over
etched, and yet another section 10mm away will be under etched.

A typical board for me is about 50mm x 50mm (2.5inX2.5in) with around 40-150
SMD components with 0.012 to 0.025 traces.

Thanks
Ron

----- Original Message -----
From: "Adam Seychell" <adam_seychell@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, January 20, 2003 11:12 PM
Subject: Re: [Homebrew_PCBs] sodium persulfate PH stabilization


> I use ammonium persulfate which I think behaves almost identical to
> sodium persulfate, I have read there are some subtle differences with
> etching between the two. I have never heard of needing to "shock" the
> solution. What is the purpose of "shocking" ?
>
> I've read that iron ions and some other metal contaminants can
> accelerate the decomposition of persulfate. The pH of persulfate
> etchants are always acidic (very low pH) because of the decomposition
> products ,
>
> 2H20 + S208(2-) -> 2H(+) + 2S04(2-) + H2O2
>
> You basically get sulfuric acid and peroxide which then further
> decomposes to release oxygen. Heat also speeds decomposition. I've got
> some solution for 2 years that I occasionally use for very light
> etching. The fact I've never heating the solution could be why its
> still showing some strength.
> A common method of completely destroy persulfate is to boil them in
> solution for ten minutes or so.
> You can switch to ferric chloride if you want an indefinite shelf
> life. Just put it in a etching tank so you never have to let the stuff
> touch anything else but the PCB.
> Recommended startup concentration for persulfate is 200g/liter of the
> salt.
>
> Ron Amundson wrote:
> > For some reason this didn't get posted last week, my apologies if it
shows
> > up twice, but I'm making boards on Wednesday, and would like some input.
> >
> > In my Kepro datasheet, it says I can shock the solution by adding some
spent
> > Sodium Persulfate so I don't have to wait for it to stabilize.
> >
> > I had some used solution which was 3 months old that I used to shock the
> > bath. I know the shelf life for etching is 3 weeks, but can it still be
used
> > to add in adjusting the pH? The experience as shown below seemed to
indicate
> > its not possible, but I want to know if I need to look at some other
reason
> > for the slow etch rate.
> >
> > I went ahead and etched, but it took forever. I was successful at 12/12,
but
> > the etching seem to take 15 - 20 minutes. When I had my techs making
proto
> > boards, it seemed we could etch in 2-4 minutes. The solution was at
105-110
> > deg F. The board was quite small, and as I use huge ground planes and
leave
> > dead copper on the board to reduce waste, It seems it should have etched
> > close to the 2 minute time frame rather than 20 minutes.
> >
> > I doing tray etching with manual agitation.
> >
> > Thanks
> > Ron
> >
> >
> > Be sure to visit the group home and check for new Bookmarks and files:
> > http://groups.yahoo.com/group/Homebrew_PCBs
> >
> > To unsubscribe from this group, send an email to:
> > Homebrew_PCBs-unsubscribe@yahoogroups.com
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
>
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>

Segue anexo tela do prg, pra quem quiser testar mando por email , 1.2 mb

Hello Ron,

21. January 2003, 06:27:25, you wrote:

RA> I need to dig up the data sheet for a better explanation, and I'll post it
RA> later.

RA> I am howver interested in your findings with ferric chloride. I've got some
RA> around here as well, and as you stated its shelf life is a real advantage. I
RA> however have never been able to acheive decent etching with it. I've tried
RA> room temperature, 50 deg C (122 deg F), agitation and aeration, and have
RA> always had problems with non-uniform etching. Part of the board gets over
RA> etched, and yet another section 10mm away will be under etched.

RA> A typical board for me is about 50mm x 50mm (2.5inX2.5in) with around 40-150
RA> SMD components with 0.012 to 0.025 traces.

RA> Thanks
RA> Ron


And I replied:

You better use copper chloride! Much safer for enviroment and you will never
throw it away! I do use the Fe3Cl only in emergencies, when boards are to be
made in less than an hour.

--
Best Regards,
Zoran
mailto:zasto@...

Ron Amundson wrote:

> I need to dig up the data sheet for a better explanation, and I'll post it
> later.
>
> I am howver interested in your findings with ferric chloride. I've got some
> around here as well, and as you stated its shelf life is a real advantage. I
> however have never been able to acheive decent etching with it. I've tried
> room temperature, 50 deg C (122 deg F), agitation and aeration, and have
> always had problems with non-uniform etching. Part of the board gets over
> etched, and yet another section 10mm away will be under etched.
>
> A typical board for me is about 50mm x 50mm (2.5inX2.5in) with around 40-150
> SMD components with 0.012 to 0.025 traces.

I only use ferric chloride. Normal double-sided 1oz Cu pcb etches between 5mins
for new solution, and 12+mins for old solution when i ditch it. I dilute it 1:1
with water, add a bit of hudrochloric acid every few months, and use it at room
temperature with some bubbles (small air pump). It is important to clean and
degrease the copper before putting any artwork on it. That's likely your
problem.

The list language is english.

Steve

--- Eduardo Perdomo <pancary@...> wrote:

>
>
> Segue anexo tela do prg, pra quem quiser testar mando por email ,
> 1.2 mb
>

__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com

In a message dated 1/21/2003 2:00:28 PM Central Standard Time,
alienrelics@... writes:

> The list language is english.
>

Touche and kudos, Steve! I.e., RIGHT ON !!!


[Non-text portions of this message have been removed]

Sorry, get translation:
I send the screen of my cnc program, if you want test it , i can send to
you by email , about 1.2 MB

http://www.geocities.com/pancary
Home Build Plotter Driver

> The list language is english.
> >
>
>Touche and kudos, Steve! I.e., RIGHT ON !!!
>
>
>[Non-text portions of this message have been removed]
>
>
>Be sure to visit the group home and check for new Bookmarks and files:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

http:\\www.geocities.com\pancary
Home Build Plotter Driver

--- Eduardo Perdomo <pancary@...> wrote:

> Sorry, get translation:
> I send the screen of my cnc program, if you want test it , i can
> send to
> you by email , about 1.2 MB
>
> http://www.geocities.com/pancary
> Home Build Plotter Driver

Can you post it to the Files section of the list?

BTW, your link is incorrect in your signature. Your slashes are
backwards.

> http:\\www.geocities.com\pancary

__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com

I'm interested, too.
Cristian

> I send the screen of my cnc program, if you want test it , i can send to
> you by email , about 1.2 MB
>
> http://www.geocities.com/pancary
> Home Build Plotter Driver

You can just go to his website and download it.

Steve

--- Cristian <bip@...> wrote:

> I'm interested, too.
> Cristian
>
>
> > I send the screen of my cnc program, if you want test it , i
> can send to
> > you by email , about 1.2 MB
> >
> > http://www.geocities.com/pancary
> > Home Build Plotter Driver
>

__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com

http://www.geocities.com/pancary/cnc.zip



At 12:48 24/01/03 -0800, you wrote:

>You can just go to his website and download it.
>
>Steve
>
>--- Cristian <bip@...> wrote:
> > I'm interested, too.
> > Cristian
> >
> >
> > > I send the screen of my cnc program, if you want test it , i
> > can send to
> > > you by email , about 1.2 MB
> > >
> > > http://www.geocities.com/pancary
> > > Home Build Plotter Driver
> >
>
>__________________________________________________
>Do you Yahoo!?
>Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
>http://mailplus.yahoo.com
>
>Be sure to visit the group home and check for new Bookmarks and files:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

http:\\www.geocities.com\pancary
Home Build Plotter Driver

http://www.geocities.com/pancary/win95io.zip
i forgot this dll , put it in windows system directory


At 17:55 25/01/03 -0200, you wrote:

>http://www.geocities.com/pancary/cnc.zip
>
>
>
>At 12:48 24/01/03 -0800, you wrote:
> >You can just go to his website and download it.
> >
> >Steve
> >
> >--- Cristian <bip@...> wrote:
> > > I'm interested, too.
> > > Cristian
> > >
> > >
> > > > I send the screen of my cnc program, if you want test it , i
> > > can send to
> > > > you by email , about 1.2 MB
> > > >
> > > > http://www.geocities.com/pancary
> > > > Home Build Plotter Driver
> > >
> >
> >__________________________________________________
> >Do you Yahoo!?
> >Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
> >http://mailplus.yahoo.com
> >
> >Be sure to visit the group home and check for new Bookmarks and files:
> >http://groups.yahoo.com/group/Homebrew_PCBs
> >
> >To unsubscribe from this group, send an email to:
> >Homebrew_PCBs-unsubscribe@yahoogroups.com
> >
> >
> >
> >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>http:\\www.geocities.com\pancary
>Home Build Plotter Driver
>
>
>Be sure to visit the group home and check for new Bookmarks and files:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

http:\\www.geocities.com\pancary
Home Build Plotter Driver