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New file uploaded to Homebrew_PCBs

 

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New file uploaded to Homebrew_PCBs

 

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Mechanical Etching PCBs

 

This is a copy of an E-Mail I sent to CAD_CAM_EDM_DRO a while back. I
thought It might be usefull to someone so I am reposting here.

Chris


Much like others are describing. After a week or so of using Protel for
board layout, use the Protel CAM processor and export the gerbers then
convert them to eagle scripts to import into eagle then converting to
outlines and outputing G-codes and then post processing them. Also I
was taking the drill files and seperately processing them. And finally
taking a board outline and processing that.

And after all that I could not work with oval pads.

The whole process was very manual and a PAIN!

Thanks to some help from this list I can now generate outlines in
Protel. I also do all the CAD work for the board outline. Then I run
the Protel CAM processor to get gerbers for top layer outline, bottom
layer outline, board outline (including tool dimensions) and NC drill
file for the holes.

I then have a post processor (Basically a scripting program and script)
that takes the files and converts them to G-Code along with tool changes
and clearance heights.

Finally I just load the G-Code files into my MaxNC and run them in
order, getting a completed board out at the end.

This new version uses far less programs works with oval pads and is a
lot more automated. Plus I have more control in Protel as to what
happens.

Chris Coley.


Re: PICBASIC-L direct PCB board printing

 

I wonder if toner would make a good solder mask, used
this way? Obviously you can't coat the whole board,
but just leaving it on the traces and cleaning it off
the pads could be a great idea.

Hmm... another use for toner. Toner is carbon and
plastic, and therefore maybe at least somewhat
conductive. Perhaps some laid down across some traces
could act as a humidity detector. With a reference one
sealed in a box for temperature compensation.

Steve Greenfield

--- Raymond Choat <rc@...> wrote:
And after printing directly to board and doing the
acid thing, leave the
printing on the board for surface protection.

----- Original Message -----
From: "jessey Montgomery"
<jessey_montgomery@...>
To: <picbasic-l@...>
Sent: Thursday, December 06, 2001 3:47 PM
Subject: Re: PICBASIC-L direct PCB board printing


Hello Victor, I am presently shoping for a laser
printer and before I read

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Re: Print on top of the pcb

thor918
 

Hi,
Don't you now any links to sites that explain this with pictures?
and do you know where to buy equipment to do this?

Thanks for the many replies :)
--- In Homebrew_PCBs@y..., JanRwl@A... wrote:
In a message dated 06-Dec-01 10:10:12 Central Standard Time,
thor918@o... writes:


Does anybody know how to print on top of the pcb.
Thor: This is done by "silk-screening". A photographically-
made "screen"
(once made only of silk, but I think, nowadays, some tougher
polyester is
used?) is used as a stencil, and PAINT is "squeegied" onto the
board. The
screen is liquid-tight in areas where you do NOT want the paint,
and only the
"screen" (open weave of the "silk" cloth) is clear, allowing paint
to squeeze
through. This is an "art" which is used in more than just PCB
work! All
kinds of posters, signs, labels, etc., are made by the
familiar "silk-screen"
method.

HOWEVER! If you just MUST have some labelling on the "top" of a
PCB, but
wanna make only ONE, and NOT spend all that for the frame, silk-
screen stock,
developer, squeegie-tool, paint, etc., you can use IMPRESSION
lettering
and/or patterns. Good art-supply stores will have more than just
letters in
that stuff! You want white or maybe yellow, but NOT black, etc.,
as those
colors hardly show on a FR-4 board. Once you have "rubbed off"
your entire
pattern, words, labels, etc., then SPRAY the top with clear enamel
or
lacquer. AFTER you have etched! And be careful not to get any of
that on the
"copper side"! It will look as nice as your steady hand can do
that! I have
done this countless times! Also, for making "professional looking"
panels!
Dial-numbers, ON/OFF, etc. Just SPRAY it after all the rubbing-
off/on is
done!

Jan Rowland


Re: Mechanical PCB etching

Bob Bozarth
 

I'm familiar with "DXF" files...Autocad right? I've been using auto cad
for years. This is my first time using it for PCB layout. I've been trying
to get a menu set up within the program to add components a little quicker
than inserting blocks. Another problem I have is getting it from the DWG
file to something I can transfer to a board. I'm new to electronics, and
find PCB design very interesting. Any Ideas?

Bob Bozarth

----- Original Message -----
From: "Alan Marconett KM6VV" <KM6VV@...>
To: <Homebrew_PCBs@...>
Sent: Friday, December 07, 2001 6:19 PM
Subject: Re: [Homebrew_PCBs] Mechanical PCB etching


Hi Tony!

Yes, surprise, surprise! To do the outlines from a Gerber file, I build
a table of nodes (typically the pads), and add connection data to each
entry. the connection data is the number of the pad to connect to, and
the trace width to use. Other data in the node is the location of the
node, size/type of pad, an the parent pad.

I then "transverse" the "nets" of the list, and output (for now) PLC
code (point, line, circle for Vector) for each arc or line segment
needed to draw a net. Each net must go completely around all pads and
traces that are connected together in a net.

Well, it's working, at least for SIMPLE layouts. No funny "stacks" of
multiple traces on top on one another. Just the simple stuff.

PLC's for now, which quickly allows me to "see" the completed nets,
later it's an easy step to generate gcode instead. It's just as if you
"traced" all around a net. It's been a challenging program to write!

I started off thinking I could generate the outlines of the pads and
traces in Vector CAD/CAM, but anything more then a couple of pads and
traces was either too much for it, or required too much manual selection
to make it work. I have wanted to do this kind of program since I got
my first IBM PC.

Sounds like you're doing a "flood fill" approach. That would remove ALL
the unwanted copper. It could work, however the work I've seen has been
outlines. Eagle can do the outlines, but as I said, I've always wanted
to do this program!

Dolphin sounds interesting, but I'd hate to spend the time (and money)
to learn it, since I'm already using Vector. The free 4-th axis does
sound interesting!

Alan KM6VV

Tony Jeffree wrote:

Hi Alan -

We meet again ;-)

I will be interested to hear how you get on - strikes me that generating
an
outline from Gerber is potentially non-trivial. Would love to make use
of
any results you generate though!

Am also looking at the possibility of using DXF track layout output &
importing that into Dolphin, then treating the tracks as a series of
"islands" for an area clear. Might just work, depending on how smart
Dolphin proves to be, but doing it that way may prove rather (mill) time
consuming compared with the outline approach. Waiting for the CD to
arrive... <sound of drumming fingers...>

Regards,
Tony


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Homebrew_PCBs-unsubscribe@...



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How I make Pcbs

High Tech
 

Hi everyone
I thought I might share how I have been making circuit boards for years.
I have made 1000's of boards using a method that some do not like but I have
had excellent results with. First I design the board on my computer using an
old program that runs in dos but is very easy to use.
I then print this out on my HP970 ink jet and make multiple copies of the
board.
Then I use the blue sheets from Techniks Inc. using a copier to lay the
final trace to the blue sheet.
Iron on the copper board using a setting on my iron of 3 yours might very,
for 1min. till the traces can be seen through the back of the blue sheet.
Use little pressure let the iron do the work if traces are smearing or
spreading then the heat is too high or your applying too much pressure.
You then peel the blue sheet off when it barely warm not yet cold. If you
have a bad trace such as a cross over this can be corrected very easily by
using a dental tool to scrape off the connected traces.

After that I just put it in the tank that has a heater and aquarium pump
3min. and you have a board.
I dip my finished boards in a solder tank to coat the traces never had a bad
board.
My boards are used on lots of equipment you don't need fancy lettering or
green coating, my boards are put in a box and never seen. They have been
working for 7years on equipment so I must be doing it right.
There are other things I do to protect the trace such as electrical coating
etc.
Hope this helps some out there get started.
Derek B.
High-Tech Systems


Re: Mechanical PCB etching

Alan Marconett KM6VV
 

Hi Tony!

Yes, surprise, surprise! To do the outlines from a Gerber file, I build
a table of nodes (typically the pads), and add connection data to each
entry. the connection data is the number of the pad to connect to, and
the trace width to use. Other data in the node is the location of the
node, size/type of pad, an the parent pad.

I then "transverse" the "nets" of the list, and output (for now) PLC
code (point, line, circle for Vector) for each arc or line segment
needed to draw a net. Each net must go completely around all pads and
traces that are connected together in a net.

Well, it's working, at least for SIMPLE layouts. No funny "stacks" of
multiple traces on top on one another. Just the simple stuff.

PLC's for now, which quickly allows me to "see" the completed nets,
later it's an easy step to generate gcode instead. It's just as if you
"traced" all around a net. It's been a challenging program to write!

I started off thinking I could generate the outlines of the pads and
traces in Vector CAD/CAM, but anything more then a couple of pads and
traces was either too much for it, or required too much manual selection
to make it work. I have wanted to do this kind of program since I got
my first IBM PC.

Sounds like you're doing a "flood fill" approach. That would remove ALL
the unwanted copper. It could work, however the work I've seen has been
outlines. Eagle can do the outlines, but as I said, I've always wanted
to do this program!

Dolphin sounds interesting, but I'd hate to spend the time (and money)
to learn it, since I'm already using Vector. The free 4-th axis does
sound interesting!

Alan KM6VV

Tony Jeffree wrote:


Hi Alan -

We meet again ;-)

I will be interested to hear how you get on - strikes me that generating an
outline from Gerber is potentially non-trivial. Would love to make use of
any results you generate though!

Am also looking at the possibility of using DXF track layout output &
importing that into Dolphin, then treating the tracks as a series of
"islands" for an area clear. Might just work, depending on how smart
Dolphin proves to be, but doing it that way may prove rather (mill) time
consuming compared with the outline approach. Waiting for the CD to
arrive... <sound of drumming fingers...>

Regards,
Tony


Re: PICBASIC-L direct PCB board printing

 

Maybe some thin heat resistant tape over the edges to
protect the drum. Is that 1/4 Oz board from Digikey?

Look for printers that say something like "true
straight-through paper path".

Or dig through the piles of laser printers showing up
now in thrift stores and just start hacking.

Steve

PS I'm hijacking this discussion to the Homebrew PCBs
list!



--- Rick Talbert <rixtalbert@...> wrote:
Dear List

I made a post about a board that is 1/4 OZ. copper a
while back . It is .031
inches thick. To thick to go thru the Laser though!
But , for some reason
,,,, like protecting the copper on the FR-104 grade
board ,there is a super
thin layer of copper that ya peel off before using.
This is the stuff you
might like. The sheets come in 8-1/2 by 11".
hate to see one of these hang up though!
And ironing it on the fiberglass is a great idea,,
but would the toner stay
on the printed copper?

Who Knows,,

RIX


-----Original Message-----
From: owner-picbasic-l@...
[mailto:owner-picbasic-l@...]On Behalf Of
victor Faria
Sent: Thursday, December 06, 2001 7:06 PM
To: picbasic-l@...
Subject: Re: PICBASIC-L direct PCB board printing


HI,Jessey
I don't think that there is anything to modify!
because I'm sure you can run card stock through a
laser printer so I think
that a thin sheet of copper would also run
through.(I think)
the only problem that I see is would the copper
being a conductor do damage
to the laser?
but now I'm thinking are there not fancy stationary
out there with gold and
silver colors,(shinny) and wouldn't this have the
same effect on the laser?
I'm just thinking out aloud.
any thoughts????
regards
victor
----- Original Message -----
From: "jessey Montgomery"
<jessey_montgomery@...>
To: <picbasic-l@...>
Sent: Thursday, December 06, 2001 7:47 PM
Subject: Re: PICBASIC-L direct PCB board printing


Hello Victor, I am presently shoping for a laser
printer and before I read
about the comments made to the picbasic group on the
subject I was concerned
about the dots per square inch of the printer (dpi)
or resolution. I've
always printed out on regular paper (using a desk
jet printer) then taken
the page to a printing shop to copy the art work on
to a transparency and
have had varying results with different shops, I
always ask to have it
copied with a laser photo copier or printer. I've
never asked the shops what
dpi their copiers were. I've always used Avery Laser
Transparencies as I
heard they were the best for circuit boards, any
comments from others as to
which ones are the best? The laser printers on the
market are 600 dpi for
the cheapest ones and 1200 dpi for the more
expensive ones. Does anyone here
know what dpi is best and will a 600 dpi do the job
ok?

Now you've sparked my interest about modifying a
laser printer to print
directly on to a circuit board or to use a thin
copper sheet as you would
the paper. Are there any more people here that know
anything more about this
subject? I would like to try something a little
innovated even if I have to
modify the new printer I buy. Thanks.......Jessey
----- Original Message -----
From: "victor Faria" <victorf@...>
To: <picbasic-l@...>
Sent: Thursday, December 06, 2001 1:51 PM
Subject: Re: PICBASIC-L direct PCB board printing


Rudie,were almost on the same page here!!!
what I mean is copper sheet.
print the sheet in the laser printer like you would
a sheet of paper.
then laminate the copper to the fiberglass board.
after lamination is complete go ahead and etch.
am I making any sense???
I would try it But I don't have a laser printer.
now does anyone know if the printer would print on
the copper sheet???
people talk about 1oz copper how many mil would
this be?
thanks
regards
Victor Faria
----- Original Message -----
From: "Rudie" <rudie@...>
To: <picbasic-l@...>
Sent: Thursday, December 06, 2001 10:41 AM
Subject: Re: PICBASIC-L direct PCB board printing


Have been toying with the same idea. I found "Copper
foil" at an art shop -
10x10cm very thin foil sheets. Haven't tried it on
the printer yet.

1Once through the printer, I was contemplating
electroplating it - which
will increase the track thickness. The tracks should
build up between the
toner. A quick brush with some etch resist on the
track side and a couple of
seconds in the etch bath should then theoretically
etch the thin copper foil
and leave the tracks alone - or actually the board
should be taken out
before the etchant starts to eat into the tracks. It
can then be stuck to
some base with those spray glue picture framers use.
I'm mainly looking at
SMD boards, but is should also work for
through-hole.

No idea if this will work.

Rudie
----- Original Message -----
From: "victor Faria" <victorf@...>
To: <picbasic-l@...>
Sent: 06 December 2001 12:48
Subject: Re: PICBASIC-L direct PCB board printing


HEY,PEOPLE I just got an idea!!!
if I"m off base here please take it easy on the
heat!!!:-).
for pc boards rather than buying pcboards say .062.
suppose you just buy the copper I don't know the
thickness I'm assuming it
will be about 5mil then rather then transfer to
copper with paper how about
you run the copper in the laser printer?????
or will this ruin the laser???
so you would print on the copper then just affix the
copper to the board .
again I don't know the procedure for this.
but I'm sure some one will.
regards
Victor Faria
----- Original Message -----
From: "Gilberto Almazan"
<gilbertofelipe@...>
To: <picbasic-l@...>
Sent: Wednesday, December 05, 2001 5:17 PM
Subject: RE: PICBASIC-L direct PCB board printing


hi, i make my own PCB?s with the tonner of a laser
printer, its easy and
cheaper (but you need practice). You only need a
photo paper (like the hp
paper), an iron and a good soap and a laser printer,
thats all.



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Re: Mechanical PCB etching

Tony Jeffree
 

Hi Alan -

We meet again ;-)

I will be interested to hear how you get on - strikes me that generating an outline from Gerber is potentially non-trivial. Would love to make use of any results you generate though!

Am also looking at the possibility of using DXF track layout output & importing that into Dolphin, then treating the tracks as a series of "islands" for an area clear. Might just work, depending on how smart Dolphin proves to be, but doing it that way may prove rather (mill) time consuming compared with the outline approach. Waiting for the CD to arrive... <sound of drumming fingers...>

Regards,
Tony

At 10:05 07/12/2001 -0800, you wrote:
Hi to the list!

I usually hang out at the CAD_CAM_EDM_DRO list, but as I have been
working towards using a CNC to "etch" a board, I thought I'd post a few
comments here!

Not that I'm anti-chemical (I've etched a few boards before), but I'm
quite taken up with the CNC approach.

I'd like to mention Eagle, which has a PCB layout program, it can
generate the outline traces with an available script.



I'm even working on generating outlines myself from Gerber files.

Alan KM6VV



To unsubscribe from this group, send an email to:
Homebrew_PCBs-unsubscribe@...



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Mechanical PCB etching

Alan Marconett KM6VV
 

Hi to the list!

I usually hang out at the CAD_CAM_EDM_DRO list, but as I have been
working towards using a CNC to "etch" a board, I thought I'd post a few
comments here!

Not that I'm anti-chemical (I've etched a few boards before), but I'm
quite taken up with the CNC approach.

I'd like to mention Eagle, which has a PCB layout program, it can
generate the outline traces with an available script.



I'm even working on generating outlines myself from Gerber files.

Alan KM6VV


Re: print on copper

 

--- Brian Pitt <bfp@...> wrote:
instead of transfers from laser printer to copper.
how about just buying a thin copper sheet say 3mil
or so.
then run the copper through the laser printer and
print your art work.

just tested this and it dosent work so well

I used 'Slug & Snail' tape its an adhesive backed
copper foil
sold in the garden dept at some stores (Seattle
area)
placed a small strip on a sheet of regular paper and
ran a
test page on an HP laserjet 1200 (nice printer for
toner transfers BTW)

got some of the letters,but many dropouts and the
toner lifted off onto
the rolls and re-deposited itself further down the
page (smear)
a second test page without the tape came
out clean and sharp ,so no damage done :-)
Very brave, foolish, or got an old cheap laser
printer. ;')

Foreseeable, I suppose, as the fuser roller is only
sized to heat up at most a thick sheet of paper, and
paper has very little heat capacity so it doesn't take
much to heat it to 400F. Copper, on the other hand,
takes a lot to heat up. Think about how long you have
to hold the iron or heat press on the board, and some
recommend preheating the board. I can only send thin
boards through my non-modified laminator.

I suspect my friend's laser printer directly on PCB
worked because it was very old and likely overpowered.

Steve Greenfield

__________________________________________________
Do You Yahoo!?
Send your FREE holiday greetings online!


Re: print on copper

 

instead of transfers from laser printer to copper.
how about just buying a thin copper sheet say 3mil or so.
then run the copper through the laser printer and print your art work.
just tested this and it dosent work so well

I used 'Slug & Snail' tape its an adhesive backed copper foil
sold in the garden dept at some stores (Seattle area)
placed a small strip on a sheet of regular paper and ran a
test page on an HP laserjet 1200 (nice printer for toner transfers BTW)

got some of the letters,but many dropouts and the toner lifted off onto
the rolls and re-deposited itself further down the page (smear)
a second test page without the tape came
out clean and sharp ,so no damage done :-)

Brian


New file uploaded to Homebrew_PCBs

 

Hello,

This email message is a notification to let you know that
a file has been uploaded to the Files area of the Homebrew_PCBs
group.

File : /Dscn0329.jpg
Uploaded by : janrwl <JanRwl@...>
Description : Home-Brew PET-ctrl. PCB-drill

You can access this file at the URL



To learn more about file sharing for your group, please visit



Regards,

janrwl <JanRwl@...>


Re: Print on top of the pcb

victor Faria
 

开云体育

I have had success doing this.
use transfer paper print your art work?using laser printer.
don't forget to mirror your image.
then iron on to the pcb.
if its a single sided pcb what I have done is give it a quick spray of clear lacquer paint makes it look pretty.
try not to let paint go over onto the solder side.
I also read 1 article where you would print to a transfer paper with an ink jet in color then transfer to the pub.
hope this helps
victor Faria

----- Original Message -----
From: JanRwl@...
Sent: Thursday, December 06, 2001 8:37 PM
Subject: Re: [Homebrew_PCBs] Print on top of the pcb

In a message dated 06-Dec-01 10:10:12 Central Standard Time, thor918@... writes:


Does anybody know how to print on top of the pcb.


Thor:? This is done by "silk-screening".? A photographically-made "screen" (once made only of silk, but I think, nowadays, some tougher polyester is used?) is used as a stencil, and PAINT is "squeegied" onto the board.? The screen is liquid-tight in areas where you do NOT want the paint, and only the "screen" (open weave of the "silk" cloth) is clear, allowing paint to squeeze through.? This is an "art" which is used in more than just PCB work!? All kinds of posters, signs, labels, etc., are made by the familiar "silk-screen" method.

HOWEVER!? If you just MUST have some labelling on the "top" of a PCB, but wanna make only ONE, and NOT spend all that for the frame, silk-screen stock, developer, squeegie-tool, paint, etc., you can use IMPRESSION lettering and/or patterns.? Good art-supply stores will have more than just letters in that stuff!? You want white or maybe yellow, but NOT black, etc., as those colors hardly show on a FR-4 board.? Once you have "rubbed off" your entire pattern, words, labels, etc., then SPRAY the top with clear enamel or lacquer. AFTER you have etched!? And be careful not to get any of that on the "copper side"!? It will look as nice as your steady hand can do that!? I have done this countless times!? Also, for making "professional looking" panels!? Dial-numbers, ON/OFF, etc.? Just SPRAY it after all the rubbing-off/on is done!

Jan Rowland

To unsubscribe from this group, send an email to:
Homebrew_PCBs-unsubscribe@...



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Re: print on copper

 

I would worry a lot about the drum getting scratched.
The copper would just have to get bent up very
slightly on an edge and you'd ruin the expensive drum.

A friend of mine used to use a laser printer to print
directly on PCB. It was some huge old thing that had a
board straight paper path. He very thoroughly deburred
the edges first.

How about those wax thermal/resin printers that print
right onto CDs? You'd only need a single color. You'd
have to either make your PCB the size and shape of a
CD or make a carrier.

Or maybe there is a market for a modified CD printer
like this. Make sure you get one that is not inkjet
and does not require special coatings. I found one for
about $2500 that is wax thermal ribbon and does not
require coated CDs. It is called the Primera Inscripta
and it is 610x305 dpi and does a CD in 5 to 10
seconds. I know, not 600dpi which is what common
wisdom says your laser printer should be for toner
transfer, but this way you don't have the transfer
step that causes lines to mush out.

It is only two colors (at once) but who cares? You
only need one color, and you can flip it over and
print the component layout.

Docs say you can take it out of the case and fit it in
a drive bay, so you could do PCB printing with zero
desktop space!

OK, who's gonna by me one to try this out? ;')







Here it is for only $2075!



Y'know, you all missed my birthday, but Christmas is
coming up soon... :'>

Steve Greenfield

--- victor Faria <victorf@...> wrote:
Hello to all!!!
I have asked this question on the picbasic list but
no answers.
a couple of thought but !!!!
now I ask all of you on the homebrew board.
instead of transfers from laser printer to copper.
how about just buying a thin copper sheet say 3mil
or so.
then run the copper through the laser printer and
print your art work.
once that's done laminate the copper to a fiberglass
board.
then etch as normal.
would this work????
does anyone see any problems with this?
or the question should be will the laser printer
print to copper sheeting??
thank you
regards
Victor Faria

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Send your FREE holiday greetings online!


print on copper

victor Faria
 

Hello to all!!!
I have asked this question on the picbasic list but no answers.
a couple of thought but !!!!
now I ask all of you on the homebrew board.
instead of transfers from laser printer to copper.
how about just buying a thin copper sheet say 3mil or so.
then run the copper through the laser printer and print your art work.
once that's done laminate the copper to a fiberglass board.
then etch as normal.
would this work????
does anyone see any problems with this?
or the question should be will the laser printer print to copper sheeting??
thank you
regards
Victor Faria


The way I do it

Paul Waller
 

开云体育

Hi all,
I have just joined this group and thought I'd share the method that I use to make PCB's. I have used a variety of methods over the years beginning with Plastic tape of 2 different colours on drafting film being double size and photographed using filters to separate the two colours and creating 2 negatives, then coating blank pcb with photoresist and drying then exposing and developing. It used to take ages to get a pcb from a design. Then when?the design didn't work.....?(Boy, did I really do all that!)
Now I use Protel Autotrax and simply print to a laser printer which I use as the positive phototool and I spray CRC onto this (as recommended by a screen printer) which makes the paper more translucent. I allow this to dry under a heat lamp, line up the two sides on a light box and tape them together. I then use KINSTEN positive acting PCB material which has a green coating and is very cheap (about $3.00 U.S. for a 100mm x 150mm sheet) I made a light box with a double fluro batten top and bottom using 4 x Philips TL20W/05 tubes and a central shelf with the centre cut out with a jigsaw. A couple of sheets of window glass which I place the pcb/artwork between. Expose for 12mins and develop in Sodium Metasilicate or KINSTEN DP50 developer (also very cheap) and etch in an Amonium Persulphate Solution in a KINSTEN tank with air bubbles from an aquarium pump. Voila! A very quick and amazingly accurate way to make prototype pcb's. I use 15 thou tracks min but could probably go thinner.
I have never tried the direct toner to pcb method but after reading from this group might give it a go.
Regards,
Paul Waller
University of Tasmania
Australia.
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Re: print on copper

 

In a message dated 06-Dec-01 17:55:59 Central Standard Time, victorf@... writes:


how about just buying a thin copper sheet say 3mil or so.
then run the copper through the laser printer and print your art work.
once that's done laminate the copper to a fiberglass board.
then etch as normal.
would this work????
does anyone see any problems with this?


Vic:? First question:? NO.? Second question:? YES!? This would be akin to training dolfins to fly.? Even if you could get the toner to stick to the copper, it ROLLS in there, and would crumble.? And, laminating it to FR-4 requires HEAT and PRESSURE, and there wouldn't even be consecutive CRUMBS of toner left on the Cu!? If this was a "good idea", it'd be "perfected" and DONE, by now!?

There are TWO ways to do homebrew PCB's:? Use "rub-off" ("impression") patterns (Radio Shack sells NICE ones that work very well, if you keep your nasty fingers away from the "good side"!).? Etch.? Drill.? OR, if you have a "CNC method" to drill on a 0.05" grid, drill the holes first, sand (deburr), and THEN do the "rub-off thing".?

Second method, OK for really-simple little PCB's:? Use FINGERNAIL polish, and PAINT the pattern on.? Use an Xacto-knife to scrape-off or shape the sloppy work, etc.? OR, press-on 3/4" wide Scotch "Magic Mending Tape" (the "frosty" Scotch-tape stuff), and then CUT the pattern with that knife, peeling-off the unwanted part.? Then etch.? If you worked neatly, and didn't get greasy fingers all over the stickum-side of the tape, this will make a FINE etch!?

Also, for "one-off" double-sided boards, DRILLING first is necessary!?

See my PCB drill in FILES.

I do this so infrequently that I just use warmed Ferric Chloride (the nasty yellow-brown stuff).? I once got some Ammonium Persulfate from one of those mail-order places in the back of the magazines, but I could never get that to work right, and it left a ruined cabinet and carpet, where it "came through" the factory-container after a year!?

If you need more than three of "same board", get 'em done? PROFESSIONALLY!? Unless you are very, very poor, and on house-arrest, so "have the time".? NOTHING beats a plated-through board for soldering leads in place!? Wicking!? Strong!? Excellent!? Lotsa luck!?? Jan Rowland


Re: Print on top of the pcb

 

In a message dated 06-Dec-01 10:10:12 Central Standard Time, thor918@... writes:


Does anybody know how to print on top of the pcb.


Thor:? This is done by "silk-screening".? A photographically-made "screen" (once made only of silk, but I think, nowadays, some tougher polyester is used?) is used as a stencil, and PAINT is "squeegied" onto the board.? The screen is liquid-tight in areas where you do NOT want the paint, and only the "screen" (open weave of the "silk" cloth) is clear, allowing paint to squeeze through.? This is an "art" which is used in more than just PCB work!? All kinds of posters, signs, labels, etc., are made by the familiar "silk-screen" method.

HOWEVER!? If you just MUST have some labelling on the "top" of a PCB, but wanna make only ONE, and NOT spend all that for the frame, silk-screen stock, developer, squeegie-tool, paint, etc., you can use IMPRESSION lettering and/or patterns.? Good art-supply stores will have more than just letters in that stuff!? You want white or maybe yellow, but NOT black, etc., as those colors hardly show on a FR-4 board.? Once you have "rubbed off" your entire pattern, words, labels, etc., then SPRAY the top with clear enamel or lacquer. AFTER you have etched!? And be careful not to get any of that on the "copper side"!? It will look as nice as your steady hand can do that!? I have done this countless times!? Also, for making "professional looking" panels!? Dial-numbers, ON/OFF, etc.? Just SPRAY it after all the rubbing-off/on is done!

Jan Rowland