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Why not use Circuit Works conductive epoxy?

I don't know if you want this around if you have kids, but MG
Chemicals makes "Liquid Tin" -- which plates in 5 minutes. The
contents are nasty -- fluoroboric acid and stannous fluoroborate.
Allied Electronics sells it, but not that they will ship all
chemicals separately and you pay a UPS surcharge for Hazmat. It's
expensive at $27 for 17 ounces.

Hi all,

To make spray-on prp resist work well, the copper has to be cleaned
well. Some things that work: salt and vinegar, salt and lemon juice,
citric acid, and probably lots of others.

I like citric acid the best, as its ok to use in the kitchen.
Mix up 30-50% powdered citric acid (sold in supermarkets), with
hot water until disolved. Wiping it over the pcb blank with paper
towel is sufficient to degrease it, without any harsh scrubbing needed.

The BLACKHOLE processes is fast, cheaper and safer to run than conventional
electroless copper. This is expected since its aim is to replace the
electroless copper line in the PCB fabrication plant. The low toxicity is the
reason I choose to develop a carbon black processes myself at home. However
the chemistry of BLACKHOLE is a trade secret and your not going to replicate
the same results at home. BLACKHOLE SP is the latest process from MacDermid
and performs many times better than the process explained below. Of course
the hobbyist doesn't need the reliability of a multimillion dollar plant
producing a hundreds of panels a day. Its taken me about 6 months of fiddling
around with carbon black dispersions, conditioning solutions and circuit
board material to get a working process suitable for home use. Basically my
process can be written down as follows;

1) drill PCB
2) clean copper surface with week solution of detergent/NaOH and 600 emery
paper.
3) rinse well with tap water
4) immerse in a "hole wall conditioner" 1 min
5) rinse well with with tap water
6) immerse in "carbon dispersion" 1 min
7) sponge off excess dispersion with sponge, so all holes are fully empty.
8) hot air dry
9) repeat steps 4 to 8
10) immerse in "activator" for 1 minute
11) rinse well with with tap water
12) microetch in a conventional non-chloride etching solution
13) spray rinse with with tap water to remove all traces of carbon on copper
surface.
14) air dry (optional)


Bath compositions/conditions;

hole wall conditioner:
5 to 10 g/l gelatine
0.04 to 0.06 g/l CuSO4.5H20 (as a biocide)
temperature between 26???C and 32???C
agitation: unnecessary


carbon dispersion:
2 to 4% (w/w) of non-ionic surfactant based
conductive carbon black dispersion paste*
6 to 10 g/l acetic acid
room temperature
agitation: unnecessary


activator:
1 g/l of dye D&C Green No.5 , C.I 61570.
room temperature
agitation: not known

non-chloride etchant:
100 to 200 g/l ammonium persulfate
or
1% hydrogen peroxide
10% sulfuric acid.
both baths may be used at room temperature.


* The carbon black dispersion paste is FLEXOBRITE BLACK 258/86 manufactured
by Degussa Coatings & Colorants.

You will have to phone around and get a 500g sample for aqueous based
non-ionic surfactant conductive carbon black dispersion. Many of the colorant
manufactures will have these. 500g will last you forever. There is still a
whole range of information I left out, either because I haven't worked it out
yet or I missed it. The D&C Green No5 is available from food, drug & cosmetic
dye suppliers, either as a sample or in small volume (1 kg). Good luck

Adam





j_hallows wrote:

PTHs are possible to do at home but you should be aware that it
involves many chemical stages. Although these chemicals are not
necessary highly toxic they can be a difficult process to control
and get working properly. So unless you find chemistry fun and
don't mind getting your hands wet then I its a complete waste of
time and money trying to implement a PTH workshop at home. I
have setup the necessary plating and etching tanks to make a tin
finish pattern plated board and had taken me almost two years.
The holes are made conductive using a processes similar to
MacDermid's BLACKHOLE processes where by a conductive carbon
black layer deposited inside the holes prior to electroplating. If
you have any questions then feel free to ask.

Hey Adam maybe you should write a produre of your method of making
PTH. I would love to know the costs involved and chemistry. I am not
familar with the BLACKHOLE method. The hardest part is making the
holes conductive. I know the squeezee method were you squeeze
conductive ink into the holes. But the ink is very expensive. Also
the Gallum method but Gallum is hard to find. Is the BLACKHOLE the
same.

Thanks.

--
John Hallows

--- In Homebrew_PCBs@y..., "j_hallows" <j_hallows@h...> wrote:

--- In Homebrew_PCBs@y..., JanRwl@A... wrote:

each! Seems plating-through should be within the realm of us ol'
home-brewers who can make a double-sided board, if we just knew

the

steps,

and where to get the chemistry to plate the holes before etching.

Could not agree more. I know the thoery but the practice it's a

whole

different ball park.

You DO know, doncha, that the PTH is done FIRST, then "SOLDER-

plating" of the

desired pattern (including through the holes!), and etch LAST,
with chemistry that will etch copper, but NOT "solder".

Took me sometime to figure this one out. But it's not solder but
tinned. And the process is called pattern plating.

As a homebrewer it is too expensive for me to send boards out to
make. If I could only find out a simple way to make plated thru

holes

at home without killing myself. And eyelets and baluns are too time
consuming.

Hi there,

I just discovered this yahoo groups forum on making PCBs at
home. Its good to see people out there making boards
themselves. When I saw the post on trying to do PTH at home I
though this could be something I might able to answer.

Making plated boards involved many more processes than a
simple 'print and etch' method. I'm sure you know that first the
holes must be made conductive in order to electroplate with
copper. This is one of the major challenges, and the industry may
use one of several techniques. I will not go into the details
because much of this information in already explained on the
web. An excellent information source is;



PTHs are possible to do at home but you should be aware that it
involves many chemical stages. Although these chemicals are not
necessary highly toxic they can be a difficult process to control
and get working properly. So unless you find chemistry fun and
don't mind getting your hands wet then I its a complete waste of
time and money trying to implement a PTH workshop at home. I
have setup the necessary plating and etching tanks to make a tin
finish pattern plated board and had taken me almost two years.
The holes are made conductive using a processes similar to
MacDermid's BLACKHOLE processes where by a conductive carbon
black layer deposited inside the holes prior to electroplating. If
you have any questions then feel free to ask.

Adam

--- robasic <robasic@...> wrote:

Jon Bevar
Founder of RoBasic Research

"Robotic Interfacing via the Personal Computer"

And added this to the SumoRobot Bookmarks.

Steve

__________________________________________________
Do You Yahoo!?
Yahoo! Sports - sign up for Fantasy Baseball

Added to the Bookmarks page.

Steve

--- robasic <robasic@...> wrote:
-snip-

Here is a FREEWARE full version of SCORE - Schematic Capture for
Windows? which there are NO limitations at all. Here is there
website:

WinCircuit2002 and WinSchema98 are a good choice for doing
schematic
drawing with WinSchema98 and then trun around and do the PCB with

WinCircuit2002. Here is there website:

-snip-

__________________________________________________
Do You Yahoo!?
Yahoo! Sports - sign up for Fantasy Baseball

Check the Bookmarks area of Homebrew PCBs.

A reminder for everyone- although the list hasn't been here that
long, a lot of people have already asked and answered a lot of
questions. I've posted some (I think) very useful links in the
Bookmarks section.

So, ask questions, but look around a bit first and see if the
answer is already here.

BTW, I am using (still learning) the free Schematic and PCB
software from CADSoft, Eagle 4. It is free for personal use.



And we're up to 171 members!

Steve Greenfield

--- David Saum <dsaum@...> wrote:

I need to draw some schematics
of my circuits, but I do not have
any software.

Any recommendations on free
or inexpensive software for
this? The simpler the better.

TIA,

Dave
The Inexpensive Seismometer Project

Yukon Gold Prospecting




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Hello Dave,

YES! There are some schematic and PCB programs out there. Eagle
Express is a FREE download with ONLY a limitation of board size (4" x
3.2" size board) but it is FULLY functional schematic editor AND is
will then create the PCB for you even including a Autorouter. Here
is there website:

Here is a FREEWARE full version of SCORE - Schematic Capture for
Windows? which there are NO limitations at all. Here is there
website:

WinCircuit2002 and WinSchema98 are a good choice for doing schematic
drawing with WinSchema98 and then trun around and do the PCB with
WinCircuit2002. Here is there website:


I hope this helps

Jon Bevar
Founder of RoBasic Research

"Robotic Interfacing via the Personal Computer"

I need to draw some schematics
of my circuits, but I do not have
any software.

Any recommendations on free
or inexpensive software for
this? The simpler the better.

TIA,

Dave
The Inexpensive Seismometer Project

Yukon Gold Prospecting

I'm saving the file to Distiller from Ultiboard, not scanning it. I
like the suggestion of using an HP G/L translator. The main thing I
want to do is save the files so that I can upload them to the web
for others to use.


--- In Homebrew_PCBs@y..., "Dave Hylands" <dhylands@b...> wrote:

Maybe you are using incorrect settings for Distiller? IIRC there

was

something about resolution (DPI).
KPL

Distiller does have a resolution setting, but this may not help

you.

Distiller keeps vector objects in the PostScript as vector objects

in the

PDF. It has the ability to resample raster objects, so if the

underlying

image in the PostScript has more resolution, then you can improve

things by

turning off resampling. Turn it off for all image types (under the
Compression Tab in Job Options). I would set Compression to ZIP,

so that

you're using lossless compression.

Otherwise, the resolution setting is for PostScript that queries to
determine what raster resolution is being used. I would set it to

a number

like 1200 or 2400, and only set it smaller if you're experiencing

file

size/display speed issues.

In Acrobat, if you crank up the magnification and you see the

pixels getting

bigger, then you're looking at raster objects. If the pixels stay

at screen

resolution, then you're looking at vector objects.

Acrobat normally displays at around 75 dpi, so at the maximum zoom

setting

of 1600%, you're one screen pixel corresponds to approximately

1200 dpi.

Most newer laser printers are 600 or 1200 dpi.

Dave Hylands

--- In Homebrew_PCBs@y..., JanRwl@A... wrote:

each! Seems plating-through should be within the realm of us ol'
home-brewers who can make a double-sided board, if we just knew the

steps,

and where to get the chemistry to plate the holes before etching.

Could not agree more. I know the thoery but the practice it's a whole
different ball park.

You DO know, doncha, that the PTH is done FIRST, then "SOLDER-

plating" of the

desired pattern (including through the holes!), and etch LAST,
with chemistry that will etch copper, but NOT "solder".

Took me sometime to figure this one out. But it's not solder but
tinned. And the process is called pattern plating.

As a homebrewer it is too expensive for me to send boards out to
make. If I could only find out a simple way to make plated thru holes
at home without killing myself. And eyelets and baluns are too time
consuming.

Yes I read all these but does anyone have any experince?



--- In Homebrew_PCBs@y..., "electronic_workshop" <hans@c...> wrote:

This link has a good description using conductive ink to actiavte

the

holes and then plate on that.



I'm using eyelets.
Recently I got some eyelet samples form Mill-Max 0.037 OD and 0.024

ID

Any know of and smaller eyelets ?

This link has a good description using conductive ink to actiavte the
holes and then plate on that.



I'm using eyelets.
Recently I got some eyelet samples form Mill-Max 0.037 OD and 0.024 ID

Any know of and smaller eyelets ?

At 10:43 PM 2/28/02 -0500, JanRwl@... wrote:

In a message dated 27-Feb-02 10:42:43 Central Standard Time,
j_hallows@... writes:

Other than using eyelets has anyone made Plated Thru Hole at Home and
can give some tips?

I use 2 methods:

'Track Pins' made by Harwin (UK, I think). We used to get them from Arrow/Bell but I don't know if they still have them.

These are a stick of tapered pins that you push into the hole, then snap off. Nice tight fit into a #66 hole. Quick, fast, reliable. Only down side is that they are good for vias only - they fill the hole so you can't put a component lead through.


Multicore makes a system called Copperset <>

This is a little stick of solid solder which has copper and tin electroplated over it. It is then scored at intervals slightly more than the average PCB thickness. You drill the via holes to the correct diameter, then insert the stick and snap off the vias one at at time. You then use an impact punch to squash the via - doing so causes the solid solder rod to expand the copper / tin coating so as to grip the sides of the hole in the PCB. Solder both sides of the via, then vacuum out the solder if you need to put a component lead in.

I have one and use if occasionally - it works well but is actually more work than the Harwin Track pins I mentioned earlier.

It works best if you use it before the board is populated - place the board on a smooth steel surface, insert the feed-through pins, then set them with the impact punch.

dwayne


Dwayne Reid <dwayner@...>
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
(780) 489-3199 voice (780) 487-6397 fax

Celebrating 18 years of Engineering Innovation (1984 - 2002)
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In a message dated 27-Feb-02 10:42:43 Central Standard Time,
j_hallows@... writes:

Other than using eyelets has anyone made Plated Thru Hole at Home and
can give some tips?

DITTO! I have OFTEN needed "onesy-twosey" PCB's with PTH, and have had to
use "jumper wires", eyelets, or have 'em made by the local PCB house for $450
each! Seems plating-through should be within the realm of us ol'
home-brewers who can make a double-sided board, if we just knew the steps,
and where to get the chemistry to plate the holes before etching.

You DO know, doncha, that the PTH is done FIRST, then "SOLDER-plating" of the
desired pattern (including through the holes!), and etch LAST, with chemistry
that will etch copper, but NOT "solder".

Someone TELL us how! GOOD topic!

Maybe you are using incorrect settings for Distiller? IIRC there was
something about resolution (DPI).
KPL

Distiller does have a resolution setting, but this may not help you.

Distiller keeps vector objects in the PostScript as vector objects in the
PDF. It has the ability to resample raster objects, so if the underlying
image in the PostScript has more resolution, then you can improve things by
turning off resampling. Turn it off for all image types (under the
Compression Tab in Job Options). I would set Compression to ZIP, so that
you're using lossless compression.

Otherwise, the resolution setting is for PostScript that queries to
determine what raster resolution is being used. I would set it to a number
like 1200 or 2400, and only set it smaller if you're experiencing file
size/display speed issues.

In Acrobat, if you crank up the magnification and you see the pixels getting
bigger, then you're looking at raster objects. If the pixels stay at screen
resolution, then you're looking at vector objects.

Acrobat normally displays at around 75 dpi, so at the maximum zoom setting
of 1600%, you're one screen pixel corresponds to approximately 1200 dpi.

Most newer laser printers are 600 or 1200 dpi.

Dave Hylands

Maybe you are using incorrect settings for Distiller? IIRC there was
something about resolution (DPI).
KPL

Other than using eyelets has anyone made Plated Thru Hole at Home and
can give some tips?