Which is the best hobby do-it-yourself method for making PCB's?

[ludo]

On Tue, 22 Nov 2005 12:30:00 +0100, Deefoo wrote:

[snip]

When I was a kid I used to use an etch-resistant ink pen (and a nail and
hamer for the holes, in fact I did the holes first) but fine-pitched
boards are not easy this way. I remember routing traces in between ic
pins (I then had a small electric drill). The pen was rather annoying
since you had to press the tip to get the ink out and often this
resulted is large blobs on the board.

--DF

Something worth trying as alternative to photoresist pens that leave blobs
like this: Staedtler Lumocolor.
Nice to touch up the bits where the positive resist or the toner transfer
didn't stick.
In my experience the black one is more resistant to FeCl than the
(somewhat) ancient Dalo photoresist pen I have here (with the blob habit.)
The red one is apparently even better. They are available in 4 tip sizes
too. (Google is good) I've tried some other overhead marker/permanent
marker type pens that didn't work well at all.

When drilling/cutting the board, use a respirator, like when
spraypainting. Saves you from waking up with an evil splitting head the
next day. One more reason to go with SMT as far as possible. Less
drilling.

L

 

[Hal Murray]

Yup. I found that the laser I'm using (NEC Superscript 1400, retired
from office use due to feed problems) is 0.8% off horizontal, and I
haven't calibrated it for vertical yet. Makes a row of 20 pins across
not quite fit, though you can cheat by snapping them in a few places and
filing down period gaps.

If you are working with postscript, it's reasonably easy to put
a wrapper around your print file that fixes up the scale. I'll fish
out the hack I've used if anybody needs it.

 

[Jasen Betts]

["Followup-To:" header set to sci.electronics.cad.]

On Tue, 22 Nov 2005 12:30:00 +0100, Deefoo wrote:

[snip]

When I was a kid I used to use an etch-resistant ink pen (and a nail and
hamer for the holes, in fact I did the holes first) but fine-pitched
boards are not easy this way. I remember routing traces in between ic
pins (I then had a small electric drill). The pen was rather annoying
since you had to press the tip to get the ink out and often this
resulted is large blobs on the board.

--DF

Something worth trying as alternative to photoresist pens that leave blobs
like this: Staedtler Lumocolor.
Nice to touch up the bits where the positive resist or the toner transfer
didn't stick.
In my experience the black one is more resistant to FeCl than the
(somewhat) ancient Dalo photoresist pen I have here (with the blob habit.)
The red one is apparently even better. They are available in 4 tip sizes
too. (Google is good) I've tried some other overhead marker/permanent
marker type pens that didn't work well at all.

Lumocolor (I assume you mean the permanent type not the dry erase)
are sometimes sold as "cdrom pens". OHP pens are hard to find, there's
not much market for them any more.

Bye.
Jasen

 

[JeffM]

...hazardous material depot in my county. I am going

But please tell them honestly what it is that you bring.
Else it can cause accidents and contamination.
Joerg

Early on, I was written up for
dispensing chemicals into smaller containers and not labeling them.
Since then, I've become a bit of a fanatic about labels.

I like to get an almost-used-up roll
of the 2" transparent tape they use in the shipping dept
and put that over the label so solvents, bleaching agents, or stains
won't have such an easy time making them unreadable.

 

[Erik Walthinsen]

If you are working with postscript, it's reasonably easy to put
a wrapper around your print file that fixes up the scale. I'll fish
out the hack I've used if anybody needs it.

Eagle has the X and Y scale in the print dialog, I just have to do some
larger-scale test prints and measurements. Wonder if I can print out a
reference rectangle bigger than the 100x80mm limit of the free version,
as long as it's e.g. the tDocu layer and not top or bottom...

 

[Robert Baer]

Early on, I was written up for
dispensing chemicals into smaller containers and not labeling them.
Since then, I've become a bit of a fanatic about labels.

I like to get an almost-used-up roll
of the 2" transparent tape they use in the shipping dept
and put that over the label so solvents, bleaching agents, or stains
won't have such an easy time making them unreadable.

"uneradable" means worse than obscene - not fit even for adults!

 

[roma]

In the past I have been using the toner transfer iron on technique.
The best I have gotten is 75-80% of the board done ... the remaining
20 - 30% is rework for missing/broken traces etc.

I am just wondering what is the best hobby do-it-yourself method?

Someone hinted at photo transfer

What has worked for you guys in the past?
What gives the best results on a fairly consistent basis?
How about double sided boards?
Thanks

I still get 99% success with the transfer method .
I have a HP 1210 laser that I set at 1200 for printing .
The secret is in the paper to use and the copper clad cleaning method .
A ) Get the following photo paper from "STAPLES" Staples brand of photo
paper , 30 sheets for $14 Canadian , stock # 18103 02238 , red package "for
inkjet printers" NO SUBSTITUTE .

B )Get a small bottle of cream cleaner used for glass- ceramic cooktop
"cerama Bryte " , "Cook Top " or similar , a bit pricy but worth it.
USE a few drops and do a good cleaning of the copper board a paper towell
then rinse under the hot water tap then dry with paper tower . DO NOT TOUCH
THE SURFACE WITH FINGERS .
Then proceed with the iron transfer take all the time needed .
Soak copper plate in soapy water in sink and after a few minutes scrub
first paper layer with fingers and thum soak some more then test for
further paper scrubbing and ensure no paper residue is visible .

Works good for me .
Roma
Home of " Handy Dandy Little Circuits "
http://members.shaw.ca/roma

 

[Chuck Harris]

"uneradable" means worse than obscene - not fit even for adults!

No it doesn't, and nor does unreadable.

You need to become familiar with a dictionary.

-Chuck

 

[samIam]

Actually I didnt need to take this step at all. The car repair shop
(where they offer 15 minute oil changes)was more than happy to
add the ferric cl to his contamination/waste disposal
binge/bottle/whatever.

I stopped by for an oil change and transmission flush and noticed the
sign "waste disposal fee - $1.20" and I asked the guy what it was for.
He replied ... that they charge to dispose the contimated engine oil
(I thought that was PART of the oil change cost) .. in any case I
casually asked if I could bring in a FeCl I have accumulated in a large
snapple plastic bottle and he said sure

I brough it in and mentioned "hey be careful that stuff will eat through
flesh and metal" and he replied "calm down, I know exactly what this
stuff is"

So I will be taking it to him after ever 6 or 7 boards I make and its
just $1.20 to add it to his waste disposal ...

case closed

 

[Chuck Harris]

Actually I didnt need to take this step at all. The car repair shop
(where they offer 15 minute oil changes)was more than happy to
add the ferric cl to his contamination/waste disposal
binge/bottle/whatever.

I stopped by for an oil change and transmission flush and noticed the
sign "waste disposal fee - $1.20" and I asked the guy what it was for.
He replied ... that they charge to dispose the contimated engine oil
(I thought that was PART of the oil change cost) .. in any case I
casually asked if I could bring in a FeCl I have accumulated in a large
snapple plastic bottle and he said sure

I brough it in and mentioned "hey be careful that stuff will eat through
flesh and metal" and he replied "calm down, I know exactly what this
stuff is"

So I will be taking it to him after ever 6 or 7 boards I make and its
just $1.20 to add it to his waste disposal ...

Wow! That really is a bad idea! FeCl is basically harmless to nature,
in small quantities, but put it in with oil, antifreeze, and other gork,
and you now have real toxic waste.

The folks that pick up this guy's waste are expecting certain contaminants
to be in the oil, but not FeCl. If they find out about the FeCl,
they will not be able to recycle the oil. They will have to send it, at
great cost, to a toxic waste disposal processor.

The FeCl will go directly to the bottom of his waste oil tank, and stay
there regardless of how many times the tank is emptied and refilled. It
will surely etch a hole in the bottom of the tank.

-Chuck

 

[John Popelish]

Wow! That really is a bad idea! FeCl is basically harmless to nature,
in small quantities, but put it in with oil, antifreeze, and other gork,
and you now have real toxic waste.

The folks that pick up this guy's waste are expecting certain contaminants
to be in the oil, but not FeCl. If they find out about the FeCl,
they will not be able to recycle the oil. They will have to send it, at
great cost, to a toxic waste disposal processor.

The FeCl will go directly to the bottom of his waste oil tank, and stay
there regardless of how many times the tank is emptied and refilled. It
will surely etch a hole in the bottom of the tank.

However, ferric chloride is very easy to chemically alter, so it is
almost completely inert in the environment. Just neutralize it with
washing soda (sodium carbonate) till it quits fizzing. Then all iron
and copper chloride will have been converted to almost insoluble iron
and copper carbonate mud. Then you can flush it down the toilet.

 

[John Larkin]

However, ferric chloride is very easy to chemically alter, so it is
almost completely inert in the environment. Just neutralize it with
washing soda (sodium carbonate) till it quits fizzing. Then all iron
and copper chloride will have been converted to almost insoluble iron
and copper carbonate mud. Then you can flush it down the toilet.

The RatShack FeCl jugs used to (still do?) advise you to flush it down
the toilet after it's used. Sounds reasonable to me... a little iron,
a little copper.

John

 

[Spehro Pefhany]

The RatShack FeCl jugs used to (still do?) advise you to flush it down
the toilet after it's used. Sounds reasonable to me... a little iron,
a little copper.

John

I think the copper compound in spent etchant can kill the 'good'
bacteria in a septic tank system, for those out of reach of municipal
water-treatment systems.


Best regards,
Spehro Pefhany

 

[Chuck Harris]

However, ferric chloride is very easy to chemically alter, so it is
almost completely inert in the environment. Just neutralize it with
washing soda (sodium carbonate) till it quits fizzing. Then all iron
and copper chloride will have been converted to almost insoluble iron
and copper carbonate mud. Then you can flush it down the toilet.

At that point, the proper thing to do would be to filter through some
paper towels, and throw the solids into the trash. Copper compounds are
extremely poisonous to fish and plants.

My whole point was that dumping the FeCl into a tank of used oil, just
because the stupid mechanic says you can is well... stupid. You, and
the environment would be better off if you dumped the waste onto the
ground, and let it kill some weeds, or trees, that you don't like.

Flushing it down the toilet isn't a real good idea either, the FeCl does
a number on the cast iron pipe that lives in many plumbing systems. Many
moons ago, I worked for a PCB manufacturing house. They wouldn't allow
me to recycle their spent FeCl (the supplier would give me about $1/gallon
for spent FeCl, two carboys was worth more than I made in a day's wages)
They dumped the waste FeCl down the floor drain in the building, and then
had to bust up the floor every other year to replace the sewer pipe.

If you dump the FeCl into a sink, it will eat out the brass traps, without
regard for how much water you flush down the sink... ask me how I know ;-)

-Chuck

 

[John Popelish]

If you dump the FeCl into a sink, it will eat out the brass traps, without
regard for how much water you flush down the sink... ask me how I know ;-)

Hence the need for pre-neutralization with washing soda. It will do
nothing to pipes after that, except, possibly line them with a bit of mud.

 

[Jim Thompson]

Hence the need for pre-neutralization with washing soda. It will do
nothing to pipes after that, except, possibly line them with a bit of mud.

I can't remember the details now, but I vaguely recall some method to
rejuvenate used FeCl.

...Jim Thompson

 

[John Popelish]

I can't remember the details now, but I vaguely recall some method to
rejuvenate used FeCl.

Add hydrochloric acid and oxygenate with air bubbles. But it
eventually becomes cupric chloride (green instead of golden brown).

 

[Rich Grise]

However, ferric chloride is very easy to chemically alter, so it is
almost completely inert in the environment. Just neutralize it with
washing soda (sodium carbonate) till it quits fizzing. Then all iron
and copper chloride will have been converted to almost insoluble iron
and copper carbonate mud. Then you can flush it down the toilet.

OK, dumb question time - does this work with sodium bicarbonate
as well? Or is it maybe not recommended because of the H in NaHCO3?

I have a confession to make - I had enough of the RS stuff to be about
an inch deep in a 9" x 12" cake pan, and I just dumped it down the storm
drain, which leads to the ocean, so I feel so guilty I should probably
turn Liberal or something[1]. ;-P I had done one double-sided board, if
that makes any difference. And the only heat I used was to set the pan in
the driveway in the sun.

Cheers!
Rich
[1] I'm a smoker, and when I'm, say, walking down the street and finish a
cigarette, if there isn't an ashtray or trash can handy I'll put the butt
in my pocket until I get to one.

 

[Rich Grise]

Hence the need for pre-neutralization with washing soda. It will do
nothing to pipes after that, except, possibly line them with a bit of mud.

Which sounds kinda like it'd be the same color as the bit of mud they
get lined with already. ;-P (ever disconnected the dump hose of a trailer
that's been sitting in a lot for 3 years? Eww!)

Cheers!
Rich

 

[Andrew Tweddle]

I can't remember the details now, but I vaguely recall some method to
rejuvenate used FeCl.

...Jim Thompson

Add a little HCl to the mix and reuse!

Andrew