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1 and 3 mil lines

1 and 3 mil lines

2009-03-07 by Derward Myrick

Stefan, Phill KAoHJBG, Leon and others that were intrested.

On Monday, February 23, 2009 1:21 PM I sent the below message
Show quoted textHide quoted text
  ----- Original Message ----- 
  From: Stefan Trethan 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Monday, February 23, 2009 1:21 PM
  Subject: Re: [Homebrew_PCBs] Re: Surface Mount


  I am using one mil copper.
  Will etch  a test board in a couple days and
  put it up for you to see.

  Derward

  I have been busy and just got around to doing it.
  Go to this site and see it.  Note that there are 4
  boards shown.  I did more but if I show more boards
  it is hard to se the traces.  Also the one labeld five mil
  is the three mill and the one labeled 3 mill is the 5 mill.
  http://www.denhamsprings.com/pcb_1mil.jpg

  Derward Myrick  KD5WWI



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

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-07 by Stefan Trethan

Thanks for making the photo.

Even allowing for the blurry image, the 1 mil line does not look one
fifth of the width of the 5 mil line?

I believe when you draw 1 mil in your PCB software, the printer
driver, printer resolution, transfer process, and etching process make
something significantly wider out of it.

Of course, lacking actual measurements on the PCB, or a way to make
those measurements, i can only make assumptions. However, given the
thickness of the copper it should be impossible to make traces
narrower than they are thick, lacking sophisticated directional
etching equipment like used for ICs.

ST
Show quoted textHide quoted text
On Sat, Mar 7, 2009 at 7:42 PM, Derward Myrick <wdmyrick@...> wrote:
> Stefan, Phill KAoHJBG, Leon and others that were intrested.
>
> On Monday, February 23, 2009 1:21 PM I sent the below message
>
>  ----- Original Message -----
>  From: Stefan Trethan
>  To: Homebrew_PCBs@yahoogroups.com
>  Sent: Monday, February 23, 2009 1:21 PM
>  Subject: Re: [Homebrew_PCBs] Re: Surface Mount
>
>
>  I am using one mil copper.
>  Will etch  a test board in a couple days and
>  put it up for you to see.
>
>  Derward
>
>  I have been busy and just got around to doing it.
>  Go to this site and see it.  Note that there are 4
>  boards shown.  I did more but if I show more boards
>  it is hard to se the traces.  Also the one labeld five mil
>  is the three mill and the one labeled 3 mill is the 5 mill.
>  http://www.denhamsprings.com/pcb_1mil.jpg
>
>  Derward Myrick  KD5WWI
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>

Re: 1 and 3 mil lines

2009-03-07 by Leon Heller

--- In Homebrew_PCBs@yahoogroups.com, "Derward Myrick" <wdmyrick@...> wrote:
>
> Stefan, Phill KAoHJBG, Leon and others that were intrested.
> 
> On Monday, February 23, 2009 1:21 PM I sent the below message
> 
>   ----- Original Message ----- 
>   From: Stefan Trethan 
>   To: Homebrew_PCBs@yahoogroups.com 
>   Sent: Monday, February 23, 2009 1:21 PM
>   Subject: Re: [Homebrew_PCBs] Re: Surface Mount
> 
> 
>   I am using one mil copper.
>   Will etch  a test board in a couple days and
>   put it up for you to see.
> 
>   Derward
> 
>   I have been busy and just got around to doing it.
>   Go to this site and see it.  Note that there are 4
>   boards shown.  I did more but if I show more boards
>   it is hard to se the traces.  Also the one labeld five mil
>   is the three mill and the one labeled 3 mill is the 5 mill.
>   http://www.denhamsprings.com/pcb_1mil.jpg
> 
>   Derward Myrick  KD5WWI

The 3 mil and 5 mil tracks look about the same, and the 1 mil track looks about 2/3 the width of the others.

Leon

Re: 1 and 3 mil lines

2009-03-07 by warrenbrayshaw

"Derward Myrick" ..> wrote:
> 
  Also the one labeld five mil
>   is the three mill and the one labeled 3 mill is the 5 mill.
>   http://www.denhamsprings.com/pcb_1mil.jpg

Assuming the IC is a soic package with 0.050 pin spacing I measure the larger traces to be around 12 mil. This is the same number I get if I assume the three square pads below the ic and slightly left mount a preset with 0.2" x 0.4" spacing.  All guesses.

Could you let us know the pin spacing of the ic used so that we have a scale. 

Thanks 
Warren

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-07 by Adam Seychell

Derward Myrick wrote:
> 
>   I have been busy and just got around to doing it.
>   Go to this site and see it.  Note that there are 4
>   boards shown.  I did more but if I show more boards
>   it is hard to se the traces.  Also the one labeld five mil
>   is the three mill and the one labeled 3 mill is the 5 mill.
>   http://www.denhamsprings.com/pcb_1mil.jpg
> 
>   Derward Myrick  KD5WWI

When PCB manufacture specifies a track/space width capability of X, then 
it should mean one can reliably create a PCB with any arbitrary pattern 
over a very large area, having trace width of X and space of X.

Come back with photos of a 100mm x 100mm PCB with 2000 parallel lines 
(i.e 1mil width/space).

Maybe we should start the 2009 Homebrew_PCB annual competition, on who 
can make finest lines. Here is a a good test pattern. A dual spiral 
covering an area 100 x 100mm.

To qualify:
continuity of trace A  and
continuity of trace B  and
insulation between A and B


  A ---------.
  B -------. |
    .----. | |
    | B  | | |
    | | A' | |
    | '----' |
    '--------'

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-07 by DJ Delorie

Stefan Trethan <stefan_trethan@...> writes:
> I believe when you draw 1 mil in your PCB software, the printer
> driver, printer resolution, transfer process, and etching process make
> something significantly wider out of it.

I know with my HP laserjet and PS, when I print a line N thou across,
I end up with a line N+1.67 thou across - the printer draws a row of
dots intersecting the edge, as well as a fill.  So a 1,3,5 mil line
would be 2.7, 4.7, and 6.7 mil.  Then you have to round up to printer
pixels - it ends up being 3.3, 5, and 6.7 mil.

I have to tell pcb to "bloat" all edges by -0.83 mil to get the print
to come out accurate, but I still choose (or chose, since I do photo
mask now) line sizes that were multiples of the printer resolution for
consistency.

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by DJ Delorie

Adam Seychell <a_seychell@...> writes:
> Maybe we should start the 2009 Homebrew_PCB annual competition, on who 
> can make finest lines. Here is a a good test pattern. A dual spiral 
> covering an area 100 x 100mm.

Here's a bunch of spiral design files:

        http://www.delorie.com/pcb/spirals/

Let the one-upping begin!

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by Derward Myrick

----- Original Message ----- 
Show quoted textHide quoted text
  From: Adam Seychell 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Saturday, March 07, 2009 2:46 PM
  Subject: Re: [Homebrew_PCBs] 1 and 3 mil lines


  . 

Adam this email was in reply to this message below.

(NOTE,  All I said was I would run under 
smd parts to save using a jumper.  This 
was to Phil and I do it all the time.  I do 
not claim to make whole boards using
1 Mil traces.  As a mater of fact I always 
use largest traces I can.  As the packages
get smaller you reach a point that you can't 
go between them.)

This was the message to which I was replying.

PHIL,

I make my regular run up to the smd and then I go with a 1 to 3 mil
line through the smd and then go back to the regular trace.
This will eliminate nost jumpers.

Derward myerick  KD5WWI 

----- Original Message ----- 
  From: Myc Holmes 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Monday, February 23, 2009 9:45 AM
  Subject: Re: [Homebrew_PCBs] Re: Surface Mount


  Hi Phil,
  I agree with you on all points. There is one "gotcha" with surface mount --
  it is more difficult to layout the pcb since placing tracks between the pins
  is near impossible. You end up with many more vias or jumpers.

  Myc

  On Mon, Feb 23, 2009 at 10:29 AM, pgdion1 <pgdion1@...> wrote:

  > Hi Jerry,
  > Once you get used to SMD, you'll never want to do through hole again!
  > I try to minimize all holes just to save drilling (which for me is the
  > biggest pain). Once you get used to them, the SMD parts are actually
  > pretty nice to work with. 0805's are the nicest and still have the
  > values marked on the package, but the 0603 size is good too if you
  > need to save space.
  >
  > As for traces, beating 15/15 is no problem with TT. 10/10 is easily
  > obtained and I do it regularly (usually 12/12 rules with 10/10 where I
  > need it like the TQFP's). In a pinch, I can do 8/8 although consistent
  > traces and spaces at this level can be difficult as I still apply my
  > toner with a hand iron ... to little pressure and the trace gets
  > sparse, to much and ... where's the space? It's very doable though and
  > many boards have a few 8/8's on them.
  >
  > My printer is an HP (both my 1200 and the 8000 series at work do an
  > excellent job ... the 1200 with reman cartridges is actually slightly
  > better).
  >
  > Hey, cool microscope for this ... the Dino Lite PC scopes. Just got
  > one at work and it is excellent! A little pricey at $320 but really a
  > nice little scope. There are many off brands for under $100 at Amazon
  > (some around 50 to 60, not as nice as the Dino Lite though). I'm going
  > to try one of those for home and hope it's not too cheesy.
  >
  > Phil (KA0HBG)
  >
  > --- In Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>, "
  > jerrytr2.com" <jerry@...> wrote:
  > >
  > > Hello,
  > >
  > > Since encountering this group a month or so ago, I have refined my
  > > toner transfer process to the point that I am able to reliably do 15-
  > > mil traces. Maybe smaller. Hope so.
  > >
  > > I'm doing a home project and have settled on PIC24F
  > > microcontrollers. The latest version needs USB, and all the PICs
  > > that support USB are surface mount. So I have been dragged kicking
  > > and screaming into the 21st century.
  > >
  > > I bought an Aoyue 968 hot-air SMD rework station and some fine
  > > tweezers and have been having a good time scrounging parts off some
  > > defunct computer boards - just to get used to the tool. I'm going to
  > > need a microscope - half of these parts just look like bits of dirt!
  > >
  > > One part I scrounged is the same package as the 24FJ256GB106
  > > processor I'm planning to use - a 64-pin TQFP. Good LORD those pins
  > > are small. Can Toner Transfer make boards this tight? According to
  > > the spec sheet, the pin pitch is .5mm, or about 20 thousandths of an
  > > inch. So the traces need to be 10 thousandths of an inch, and will
  > > only have 10 thousandths of separation. Ouch.
  > >
  > > - Jerry Kaidor
  > >
  >
  > 
  >

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


  
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  Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe NOTE,  All I said was I would run under 
  smd parts to save using a jumper.  This 
  was to Phil and I do it all the time.  I do 
  not claim to make whole boards using
  1 Mil traces.  As a mater of fact I always 
  use largest traces I can.
  .


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

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by Stefan Trethan

Yes i know, you already wrote at some point it's only reliable for short tracks.
But even that i doubt, since the mechanics of etching shouldn't allow
a track narrower than it's height without lots of trouble.
I think you just end up with slightly wider tracks than you think.

Not that it matters, you can still use them to run through IC pads. I
just would have been curious if there was a way to make seriously
narrow traces.

ST
Show quoted textHide quoted text
On Sun, Mar 8, 2009 at 1:36 AM, Derward Myrick <wdmyrick@...> wrote:

> Adam this email was in reply to this message below.
>
> (NOTE,  All I said was I would run under
> smd parts to save using a jumper.  This
> was to Phil and I do it all the time.  I do
> not claim to make whole boards using
> 1 Mil traces.  As a mater of fact I always
> use largest traces I can.  As the packages
> get smaller you reach a point that you can't
> go between them.)
>

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by Adam Seychell

DJ Delorie wrote:
> Here's a bunch of spiral design files:
> 
>         http://www.delorie.com/pcb/spirals/
> 
> Let the one-upping begin!
> 

That is an impressive sample of PCB testing artwork you created.
I'll definitely try some of those one day.

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by Jim

Stefan Trethan wrote:
> Yes i know, you already wrote at some point it's only reliable for short tracks.
> But even that i doubt, since the mechanics of etching shouldn't allow
> a track narrower than it's height without lots of trouble.
> I think you just end up with slightly wider tracks than you think.
>
> Not that it matters, you can still use them to run through IC pads. I
> just would have been curious if there was a way to make seriously
> narrow traces.
>
> ST
>   
If you start out with VERY thin copper (say 1/10 the thickness of 1 oz 
copper) ... lay down a 1.5 mil resist and etch it ... drill holes ... 
activate holes ... then plate the copper up to the thickness of 1 oz 
copper ... would this result in narrow traces? ...  or is the limit in 
the photo/printer part of the process? ... some how the professional 
houses get very narrow traces and the edges look very good under 
magnification!
Jim
Show quoted textHide quoted text
> On Sun, Mar 8, 2009 at 1:36 AM, Derward Myrick <wdmyrick@...> wrote:
>
>   
>> Adam this email was in reply to this message below.
>>
>> (NOTE,  All I said was I would run under
>> smd parts to save using a jumper.  This
>> was to Phil and I do it all the time.  I do
>> not claim to make whole boards using
>> 1 Mil traces.  As a mater of fact I always
>> use largest traces I can.  As the packages
>> get smaller you reach a point that you can't
>> go between them.)
>>
>>     
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>
>
>

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by DJ Delorie

Adam Seychell <a_seychell@...> writes:
> That is an impressive sample of PCB testing artwork you created.

Thanks!  That's one of the advantages of text-based file formats.  I
wrote a perl script to generate the *.pcb files from the given
spacing, then used pcb's command line options to export those files in
various formats.  Once I had the perl script and a shell script
wrapper, I just run the wrapper and everything gets generated.

The only one that was manual was the sample picture, where I moved one
of the traces to a different layer to change the color.

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by Adam Seychell

DJ Delorie wrote:
> 
> Thanks!  That's one of the advantages of text-based file formats.  I
> wrote a perl script to generate the *.pcb files from the given
> spacing, then used pcb's command line options to export those files in
> various formats.  Once I had the perl script and a shell script
> wrapper, I just run the wrapper and everything gets generated.
>
> 
What that a separate command line tool you used to generate the .grb, 
.drl and .pdf files from the .pcb file ?

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by Stefan Trethan

I think if you plate it up afterwards it will widen again. Besides,
you need to contact all traces for plating so it is impractical for
real boards.
Thinner copper would definitely reduce the problems with underetching.

Professional board houses have a number of factors working in their
favour. They have high resolution imaging/plotting equipment so they
can actually draw fine lines. Their photoprocess supports transferring
those fine lines to resist using well collimated light and a number of
other factors i probably never even considered.
Then they have spray etchers which assure an even etch over the whole
area, so they don't have to over-etch so much. Also, spray etching
shows much greater directionality than immersion etching.  The etching
process is carefully controlled (chemistry, temperature, etc..).
All in all, i think they can reduce the tolerances in just about every
step compared to our homebrew work.

I'm not saying fine lines are something to work towards. 8mil or
6.66mil is more than small enough, even for the boards i design for
production. I would not want to make any smaller traces simply for
electrical reasons. So i have no desire to push towards finer lines in
my homebrew setup, merely a curiosity about how it would be possible.

ST
Show quoted textHide quoted text
On Sun, Mar 8, 2009 at 7:54 AM, Jim <jhutch17@...> wrote:

> If you start out with VERY thin copper (say 1/10 the thickness of 1 oz
> copper) ... lay down a 1.5 mil resist and etch it ... drill holes ...
> activate holes ... then plate the copper up to the thickness of 1 oz
> copper ... would this result in narrow traces? ...  or is the limit in
> the photo/printer part of the process? ... some how the professional
> houses get very narrow traces and the edges look very good under
> magnification!
> Jim

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by Simao Cardoso

Professional board houses (but not small ones) use pattern plating after
negative print. They start with thin layer plain copper, leave the dry
film where is to etch copper, and copper plate up to desired copper
thick. Then they tin plate above the copper tracks. And they they remove
all the dry film before etch. This way they end with plain thin copper
where is to etch copper away and tracks that are higher levels of copper
and which are tin plated above and incredibly also on sides. After they
etch in alkaline spray baths (complex mixture of ammonia and
sulfuric/hydrochloride/nitric acids with phosphoric acid to don't etch
the tin) but the etchant only removes the really thin copper, the tracks
are already much higher. If over etch occurs you always see the correct
width from above. 
Metallic resist is the only way to do plated holes bellow 0.5mm and thin
tracks bellow 0.3mm. But if is used tin it has to be removed because of
tin whiskers. This is done in simple hight concentrated NaOH bath (tin
can be removed and reused again over and over).

All this can be done at home with toner transfer and Peroxy-sulfuric
with phosphoric acid for tin resist, ammonia/sodium persulfate for
nickel resist or cupric chloride for gold resist.

The still remaining problem is hole activation for plating...

Regards,
Simao
Show quoted textHide quoted text
On Sun, 2009-03-08 at 10:55 +0100, Stefan Trethan wrote:
> I think if you plate it up afterwards it will widen again. Besides,
> you need to contact all traces for plating so it is impractical for
> real boards.
> Thinner copper would definitely reduce the problems with underetching.
> 
> Professional board houses have a number of factors working in their
> favour. They have high resolution imaging/plotting equipment so they
> can actually draw fine lines. Their photoprocess supports transferring
> those fine lines to resist using well collimated light and a number of
> other factors i probably never even considered.
> Then they have spray etchers which assure an even etch over the whole
> area, so they don't have to over-etch so much. Also, spray etching
> shows much greater directionality than immersion etching. The etching
> process is carefully controlled (chemistry, temperature, etc..).
> All in all, i think they can reduce the tolerances in just about every
> step compared to our homebrew work.
> 
> I'm not saying fine lines are something to work towards. 8mil or
> 6.66mil is more than small enough, even for the boards i design for
> production. I would not want to make any smaller traces simply for
> electrical reasons. So i have no desire to push towards finer lines in
> my homebrew setup, merely a curiosity about how it would be possible.
> 
> ST
> 
> On Sun, Mar 8, 2009 at 7:54 AM, Jim <jhutch17@...> wrote:
> 
> > If you start out with VERY thin copper (say 1/10 the thickness of 1
> oz
> > copper) ... lay down a 1.5 mil resist and etch it ... drill
> holes ...
> > activate holes ... then plate the copper up to the thickness of 1 oz
> > copper ... would this result in narrow traces? ...  or is the limit
> in
> > the photo/printer part of the process? ... some how the professional
> > houses get very narrow traces and the edges look very good under
> > magnification!
> > Jim
> 
> 
> 
>

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by DJ Delorie

Adam Seychell <a_seychell@...> writes:
> What that a separate command line tool you used to generate the .grb, 
> .drl and .pdf files from the .pcb file ?

PCB itself has command line options, which we use extensively in
Makefiles to automate things like web pages, etch prints, and fab
submissions.  For example, I added a "photo mode" sample export from
the tool to the web page, an export we use for all our documentation.
The same PNG export I used for the red/blue image, in inverted
monochrome at 2880 DPI, produces my photo masks:

%-f.png : %.pcb
	pcb -x png --dpi 2880 --outfile $*-f.tmp --monochrome --as-shown --layer-stack 0,pins,vias $<
	pngtopnm $*-f.tmp | ppmtopgm | pgmtopbm | pnminvert | pamflip -lr | pnmtopng > $*-f.pnm.tmp
	mv $*-f.pnm.tmp $*-f.pnm
	rm $*-f.tmp

The wrapper script looks like this ("pcb" is the board layout tool):

-----------------------------------------------------------------------------
#!/bin/bash

echo > index.html

sp()
{
  ./make-spiral $1 $2
  pcb -x gerber spiral-$1$2.pcb
  pcb -x ps --xcalib 1 --ycalib 1 --ps-bloat 0 --multi-file spiral-$1$2.pcb
  ps2pdf spiral-$1$2.front.ps

  echo "<tr><td>$1 $2</td>" >> index.html
  echo "<td><a href=spiral-$1$2.pcb>pcb</a></td>" >> index.html
  echo "<td><a href=spiral-$1$2.gbr>gbr</a></td>" >> index.html
  echo "<td><a href=spiral-$1$2.drl>drl</a></td>" >> index.html
  echo "<td><a href=spiral-$1$2.pdf>pdf</a></td>" >> index.html
  echo "</tr>" >> index.html
}

echo "<tr><td colspan=5><h2>Imperial</h2></td></tr>" >> index.html
for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
do
  sp $i mil
done

echo "<tr><td colspan=5><h2>Metric</h2></td></tr>" >> index.html
for i in 0.05 0.10 0.15 0.20 0.25 0.30 0.35
do
  sp $i mm
done

echo "<tr><td colspan=5><h2>600 dpi</h2></td></tr>" >> index.html
for i in 1.66 3.33 6.67 8.33
do
  sp $i mil
done

-----------------------------------------------------------------------------

And the script which picks out the files I want for the web page
looks like this:

-----------------------------------------------------------------------------

#!/bin/bash
# -*- sh -*-

web=/home/web/pcb/spirals/
test -d $web || mkdir $web

for i in spiral-*.pcb
do
  base=`echo $i | sed s/.pcb//`;
  cp $i $web
  cp $base.front.gbr $web/$base.gbr
  cp $base.plated-drill.cnc $web/$base.drl
  cp $base.front.pdf $web/$base.pdf
done

cp index.html $web/options.html

-----------------------------------------------------------------------------

And, for the really hard core, here's the perl script which generates
the spiral layouts:

-----------------------------------------------------------------------------

#!/usr/bin/perl
# -*- perl -*-

$mil = 100;
$in = 1000 * $mil;
$cm = $in / 2.54;
$mm = $cm / 10;

$max = 10 * $cm;

$w = shift;
$wu = shift;
$wname = "$w$wu";
$wu = ($wu eq "mm") ? $mm : $mil;
$w = int ($w * $wu + 0.5);
$pw = 80 * $mil;
$pd = 30 * $mil;

#$pw = 240 * $mil;
#$pd = 90 * $mil;

$cx = $max * 1.1 / 2;
$cx = int($cx/$w)*$w;
$cy = $cx;
$pcb = int($cx * 2);

$loops = ($max/2 - $pw) / ($w*2);
$loops = int ($loops/2) * 2;

$w2 = $w * 2;

#-----------------------------------------------------------------------------

&pcb_start();

&pin(-$w/2-$pw/2, -$w);
&pin( $w/2+$pw/2,  $w);

&pin(-$pw/2-$w2-$w/2-$w2*($loops-1), -$pw-$w2*$loops);
&pin($pw/2+$w/2+$w2*$loops, -$pw-$w2*($loops-1));

&pcb_layer();

for ($i=0; $i<$loops; $i++) {

    &hline (-$pw-$w2-$w2*$i, $pw+$w2*$i, $pw/2+$w/2+$w2*$i);
    &vline (-$pw-$w2-$w2*$i, $pw/2+$w/2+$w2*$i, -$pw/2-$w/2-$w2*($i+1));

    &hline (-$pw-$w2*$i, $pw+$w2+$w2*$i, -$pw/2-$w/2-$w2*$i);
    &vline ($pw+$w2*$i, $pw/2+$w/2+$w2*$i, -$pw/2-$w/2-$w2*($i-1));
}

$w = 100 * $mil;
$cx = $cy = 0;

&vline ($w/2, $pcb-$w/2, $w/2);
&vline ($pcb-$w/2, $pcb-$w/2, $w/2);
&hline ($w/2, $pcb-$w/2, $w/2);
&hline ($w/2, $pcb-$w/2, $pcb-$w/2);

&pcb_end();

#-----------------------------------------------------------------------------

sub pcb_start {
    open(PCB, "> spiral-$wname.pcb");
    select PCB;
    print <<EOF;
FileVersion[20070407]

PCB["" $pcb $pcb]

Grid[500.000000 0 0 1]
Cursor[0 0 0.000000]
PolyArea[200000000.000000]
Thermal[0.500000]
DRC[1000 1000 1000 1000 1500 1000]
Flags("rubberband,nameonpcb,uniquename,clearnew,snappin")
Groups("1,c:2,s:3:4:5:6:7:8")
Styles["Signal,1000,8000,2800,1000:Power,2500,6000,3500,1000:Fat,4000,6000,3500,1000:Skinny,600,2402,1181,600"]

Element["" "" "" "" 0 0 0 0 0 100 ""]
(
EOF
}

sub pcb_layer {
    print <<EOF;
	)
Layer(1 "component")
(
EOF
}

sub pcb_end {
    print <<EOF;
)
Layer(2 "solder")
(
)
Layer(3 "silk")
(
)
Layer(4 "silk")
(
)
EOF
    select STDOUT;
    close PCB;
}

sub pin {
    my ($x, $y) = @_;
    printf("\tPin[%d %d %d %d %d %d \"\" \"\" \"square\"]\n",
	   $x+$cx, $y+$cy, $pw, $w, $pw, $pd);
}

sub hline {
    my ($x1, $x2, $y) = @_;
    &line($x1, $y, $x2, $y);
}
sub vline {
    my ($x, $y1, $y2) = @_;
    &line($x, $y1, $x, $y2);
}

sub line {
    my ($x1, $y1, $x2, $y2) = @_;
    printf("  Line[%d %d %d %d %d %d \"\"]\n",
	   $x1+$cx, $y1+$cy, $x2+$cx, $y2+$cy, $w, $w);
}

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by DJ Delorie

Simao Cardoso <simaocardoso@...> writes:
> cupric chloride for gold resist.

Has anyone tried gold-plating at home?  I think that would be impressive :-)

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by leon Heller

----- Original Message ----- 
Show quoted textHide quoted text
From: "DJ Delorie" <dj@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, March 08, 2009 6:19 PM
Subject: Re: [Homebrew_PCBs] 1 and 3 mil lines


>
> Simao Cardoso <simaocardoso@...> writes:
>> cupric chloride for gold resist.
>
> Has anyone tried gold-plating at home?  I think that would be impressive 
> :-)

Some processes involve cyanide, it might not be a good idea.

Leon
--
Leon Heller
Amateur radio call-sign  G1HSM
Yaesu FT-817ND transceiver
Suzuki SV1000S motorcycle
leon355@...
http://www.geocities.com/leon_heller

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by DJ Delorie

"leon Heller" <leon355@...> writes:
> Some processes involve cyanide, it might not be a good idea.

A bit of googling says there's non-cyanide (i.e. high acid) processes
available.

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-08 by Simao Cardoso

> 
> Has anyone tried gold-plating at home? I think that would be
> impressive :-)
> 
> 

The gold plating (electroplating) isn't that hard. Today it's used non
hazard alkaline solutions of gold alloy in sodium thiosulfate. 
You can buy these solutions cheap (15eur) for home gold electroplating
of bathroom water taps. It has very low gold in it but they show with a
simple 12V 500mA wall transformer you can electro plate things with a
cotton terminal with the solution on it. 
So if you do negative print of the pcb artwork in your board you can use
this simple method to electro plate the entire tracks before etch. 
And because gold is resistant to cupric chloride you can start just now.
If you intent to do a lot boards, instead of buy a lot of liquid i think
you can buy a 1g bullion gold per 25eur and use it as electrode inside
the cotton.

But all that seems easy to me, still hard is a away to activate holes at
home. And soldermask...


Regards,
Simao
>

terminology question:

2009-03-09 by Piers Goodhew

Hi All,

What is the term for the process where your traces are simply  
"outlined" by etching, and as a result, most of the copper is left on  
the board, and you presumably use a lot less etchant (and maybe get  
some 2D RF shielding as well).

What I'm talking about is used by SparkFun a lot, as in: http://www.sparkfun.com/commerce/images/products/00718-02-L.jpg

I suppose I have two questions really:

1 - what do you call this?
2 - is there a handy one-click way to do it in major CAD packages?

PG

Re: [Homebrew_PCBs] terminology question:

2009-03-09 by DJ Delorie

What you're looking for is most likely called a "ground plane flood"
and most EDA packages support it.  In the sparkfun link, note that the
GND pin in the lower left is electrically connected to the plane, as
are a few other pins.

In PCB, to get this, draw a rectangle over the board, and use the
thermal tool to connect pins to it, or the 'j' key to join lines to
it.

Re: terminology question:

2009-03-09 by Viper62

--- In Homebrew_PCBs@yahoogroups.com, Piers Goodhew <piers@...> wrote:
I use Eagle 4.16, to do this, I use the Polygon button, I select the layer I want to use then I draw around the the board's edge to cover the whole board, when done I right click to stop the polygon then I click ratsnest, If you want to use it as a ground or another signal, click on the name button and rename it to the signal you want, ex. gnd or ground.
Show quoted textHide quoted text
>
> Hi All,
> 
> What is the term for the process where your traces are simply  
> "outlined" by etching, and as a result, most of the copper is left on  
> the board, and you presumably use a lot less etchant (and maybe get  
> some 2D RF shielding as well).
> 
> What I'm talking about is used by SparkFun a lot, as in: http://www.sparkfun.com/commerce/images/products/00718-02-L.jpg
> 
> I suppose I have two questions really:
> 
> 1 - what do you call this?
> 2 - is there a handy one-click way to do it in major CAD packages?
> 
> PG
>

Re: [Homebrew_PCBs] terminology question:

2009-03-09 by leon Heller

----- Original Message ----- 
Show quoted textHide quoted text
From: "Piers Goodhew" <piers@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, March 09, 2009 12:43 PM
Subject: [Homebrew_PCBs] terminology question:


> Hi All,
>
> What is the term for the process where your traces are simply
> "outlined" by etching, and as a result, most of the copper is left on
> the board, and you presumably use a lot less etchant (and maybe get
> some 2D RF shielding as well).
>
> What I'm talking about is used by SparkFun a lot, as in: 
> http://www.sparkfun.com/commerce/images/products/00718-02-L.jpg
>
> I suppose I have two questions really:
>
> 1 - what do you call this?
> 2 - is there a handy one-click way to do it in major CAD packages?

It's called "isolation milling" when done with CNC. There isn't an easy way 
to do it with most PCB packages.

Leon

Re: terminology question:

2009-03-09 by pgdion1

--- In Homebrew_PCBs@yahoogroups.com, Piers Goodhew <piers@...> wrote:
>
> Hi All,
> 
> What is the term for the process where your traces are simply  
> "outlined" by etching, and as a result, most of the copper is left on  
> the board, and you presumably use a lot less etchant (and maybe get  
> some 2D RF shielding as well).
> 


It's called a flood or a copper pour.  Both OrCAD and DipTrace refer to it as a pour (I highly recommend DipTrace).  You can select which net to connect it too or you can leave it isolated to just save on etching. I always connect mine to ground to create a ground plane on the top surface. It's good for both analog and RF circuitry.  Select the pour function and draw the area you want to fill. Usually this would just be the outline of the whole board.  From the Pour settings, you can specify the keep-away (the gaps from the traces and objects) and also the size and number of the connections at each node connected to the selected net (say ground). The nice thing about pours (as opposed to planes) is you can make them any shape and you can have more than one on a layer. They're a great way to do split power planes. In this way you can have only a 2 layer board and still have a Vdd and a Ground plane. A copper pour on top with a few vias to the bottom helps give good ground coverage all over the board. I have one picture of a flood posted here ... 
http://groups.yahoo.com/group/Homebrew_PCBs/photos/album/1406912540/pic/list

Note, I usually use a cross-hatch pattern as this keeps the laser's drum from loading up. I'll try to remember to upload some more images soon.
Phil (KA0HBG)

Re: [Homebrew_PCBs] terminology question:

2009-03-09 by Paul Playford

Flooding.  There is a CAD package that does this, maybe ORCAD.

de Paul, W8AEF

ZF2JI/ZF2TA  FO8DX/FO8PLA  8Q7AA  XZ0A  VU7RG  TX5C


----- Original Message ----- 
Show quoted textHide quoted text
From: "Piers Goodhew" <piers@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, March 09, 2009 5:43 AM
Subject: [Homebrew_PCBs] terminology question:


> Hi All,
>
> What is the term for the process where your traces are simply
> "outlined" by etching, and as a result, most of the copper is left on
> the board, and you presumably use a lot less etchant (and maybe get
> some 2D RF shielding as well).
>
> What I'm talking about is used by SparkFun a lot, as in: 
> http://www.sparkfun.com/commerce/images/products/00718-02-L.jpg
>
> I suppose I have two questions really:
>
> 1 - what do you call this?
> 2 - is there a handy one-click way to do it in major CAD packages?
>
> PG
>

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-09 by Mike Schoenborn

At 07:29 PM 3/7/2009 -0500, you wrote:

>Here's a bunch of spiral design files:
>
>        http://www.delorie.com/pcb/spirals/

From the web page...

"...(outer pad to corresponding inner pad = 0 ohms)..."

Come on now, you're dealing with engineers here! :-)

Can the Perl code be twiddled to report the length of the
resulting tracks?  I'm sure someone here (with better memory
than me) could use that information to compute what the
actual resistance should really be.

I'm guessing that the length of the smaller tracks would result
in a non-zero resistance measurable with a better DVM.  Such a
measurement might be a clue to the quality of the resulting board,
as opposed to simply "open/short = pass/fail".

(Actually, measuring the capacitance would probably be a better
metric... hmmm.)

I'd really like to etch a few versions of those spirals, but I have to
wait patiently for Old Man Winter to leave before I can start to
work out in the garage again.

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-09 by DJ Delorie

Mike Schoenborn <rtfm@...> writes:

> Come on now, you're dealing with engineers here! :-)

Well, yeah.

> Can the Perl code be twiddled to report the length of the
> resulting tracks?  I'm sure someone here (with better memory
> than me) could use that information to compute what the
> actual resistance should really be.

PCB can report that, it's on the order of 60 feet each for the 5 mil
board - about 140 ohms at 0.5oz!

The 1 mil board at 0.5oz is 315 feet, and about 3.7k ohms.

Ok, maybe I'll add the math to the perl script ;-)

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-09 by Stefan Trethan

I think 0 Ohm was a good guess for the 1 mil board.
After all it displays as a black square on my screen (without zoom)
and will probably print just about the same ;-)

If i can win by least resistance it's in the bag already ;-)

ST
Show quoted textHide quoted text
On Mon, Mar 9, 2009 at 6:15 PM, DJ Delorie <dj@...> wrote:

>
> The 1 mil board at 0.5oz is 315 feet, and about 3.7k ohms.
>
> Ok, maybe I'll add the math to the perl script ;-)
>
>

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-09 by DJ Delorie

DJ Delorie <dj@...> writes:
> Ok, maybe I'll add the math to the perl script ;-)

Added.

http://www.delorie.com/pcb/spirals/

Re: [Homebrew_PCBs] 1 and 3 mil lines

2009-03-09 by Piers Goodhew

I'm not sure how many late model MacBook Pro users are on here, but if  
you view the PDF (all nice an anti-aliased) and do the "pinch-to-zoom"  
thing, the results are just about mind-altering (you get the spirals  
moving out and moire patterns moving in/out and if you were standing  
up you'd fall down)

PG
Show quoted textHide quoted text
On 10/03/2009, at 4:31 AM, Stefan Trethan wrote:

> I think 0 Ohm was a good guess for the 1 mil board.
> After all it displays as a black square on my screen (without zoom)
> and will probably print just about the same ;-)
>
> If i can win by least resistance it's in the bag already ;-)
>
> ST
>
> On Mon, Mar 9, 2009 at 6:15 PM, DJ Delorie <dj@...> wrote:
>
> >
> > The 1 mil board at 0.5oz is 315 feet, and about 3.7k ohms.
> >
> > Ok, maybe I'll add the math to the perl script ;-)
> >
> >

Re: [Homebrew_PCBs] Re: terminology question:

2009-03-09 by Piers Goodhew

Works in Eagle 5.1x free and officially rocks! Thankyou!

PG
Show quoted textHide quoted text
On 10/03/2009, at 1:35 AM, Viper62 wrote:

> --- In Homebrew_PCBs@yahoogroups.com, Piers Goodhew <piers@...> wrote:
> I use Eagle 4.16, to do this, I use the Polygon button, I select the  
> layer I want to use then I draw around the the board's edge to cover  
> the whole board, when done I right click to stop the polygon then I  
> click ratsnest, If you want to use it as a ground or another signal,  
> click on the name button and rename it to the signal you want, ex.  
> gnd or ground.

Re: [Homebrew_PCBs] Re: terminology question:

2009-03-09 by Piers Goodhew

Next question:

If I flood my current design, I get quite a few "Islands" which cannot  
be grounded. Is it a bad idea to flood them as you'll induce all kinds  
of voodoo, or is it perfectly safe?

PG
Show quoted textHide quoted text
On 10/03/2009, at 1:35 AM, Viper62 wrote:

> --- In Homebrew_PCBs@yahoogroups.com, Piers Goodhew <piers@...> wrote:
> I use Eagle 4.16, to do this, I use the Polygon button, I select the  
> layer I want to use then I draw around the the board's edge to cover  
> the whole board, when done I right click to stop the polygon then I  
> click ratsnest, If you want to use it as a ground or another signal,  
> click on the name button and rename it to the signal you want, ex.  
> gnd or ground.

Re: [Homebrew_PCBs] Re: terminology question:

2009-03-09 by DJ Delorie

Piers Goodhew <piers@...> writes:
> If I flood my current design, I get quite a few "Islands" which cannot  
> be grounded. Is it a bad idea to flood them as you'll induce all kinds  
> of voodoo, or is it perfectly safe?

It depends on what your circuit is.  IMHO in general grounding is
better than not grounding, but I've done plenty of slow-clock boards
with unconnected copper just to keep the etching happy.

Usually, by the time you need to worry about these issues, you know
the answer ;-)

BTW in PCB, such islands are automatically removed unless you
explicitly mark them to be kept.

Re: terminology question:

2009-03-10 by warrenbrayshaw

Piers Goodhew  wrote:
>
> Next question:
> 
> If I flood my current design, I get quite a few "Islands" which cannot  
> be grounded. Is it a bad idea to flood them as you'll induce all kinds  
> of voodoo, or is it perfectly safe?


In Eagle if you flood-fill a polygon without first specifying the net the flooded polygon should connect to (like GND ) it will create these "islands".

Have a practice with the Eagle Tutorial (page 56 in Version4), and you will see it won't create the islands if you relate the polygon to GND or any other net before flooding it. 

i.e. If an island cannot attach to a net with the same name as that of the polygon then the island isn't created. Just what you wanted.

Additionally if you 'do not' name the polygon then the flood fill will not connect to any points inside the polygon. So what appears as a good flood fill is really a super island not connected to any point. Looks pretty and saves etchchant but not likely what you were after. 

Hope this helps
Warren

Re: terminology question:

2009-03-10 by Viper62

--- In Homebrew_PCBs@yahoogroups.com, Piers Goodhew <piers@...> wrote:
>
> Next question:
> 
> If I flood my current design, I get quite a few "Islands" which cannot  
> be grounded. Is it a bad idea to flood them as you'll induce all kinds  
> of voodoo, or is it perfectly safe?
> 
> PG
I personally have not had any problems using this method, some of my earlier designs were done without using this technique and I had problems with poor ground so I started using ground planes(copper pour), some of my newer designs use RF tranceivers and I haven't had any problems. If you need to, I think you can leave the "islands" isolated from ground without any problems.
Show quoted textHide quoted text
> On 10/03/2009, at 1:35 AM, Viper62 wrote:
> 
> > --- In Homebrew_PCBs@yahoogroups.com, Piers Goodhew <piers@> wrote:
> > I use Eagle 4.16, to do this, I use the Polygon button, I select the  
> > layer I want to use then I draw around the the board's edge to cover  
> > the whole board, when done I right click to stop the polygon then I  
> > click ratsnest, If you want to use it as a ground or another signal,  
> > click on the name button and rename it to the signal you want, ex.  
> > gnd or ground.
>

Re: terminology question:

2009-03-10 by Viper62

--- In Homebrew_PCBs@yahoogroups.com, "warrenbrayshaw" <warrenbrayshaw@...> wrote:
>
> Piers Goodhew  wrote:
> >
> > Next question:
> > 
> > If I flood my current design, I get quite a few "Islands" which cannot  
> > be grounded. Is it a bad idea to flood them as you'll induce all kinds  
> > of voodoo, or is it perfectly safe?
> 
> 
> In Eagle if you flood-fill a polygon without first specifying the net the flooded polygon should connect to (like GND ) it will create these "islands".
> 
> Have a practice with the Eagle Tutorial (page 56 in Version4), and you will see it won't create the islands if you relate the polygon to GND or any other net before flooding it. 
> 
> i.e. If an island cannot attach to a net with the same name as that of the polygon then the island isn't created. Just what you wanted.
> 
> Additionally if you 'do not' name the polygon then the flood fill will not connect to any points inside the polygon. So what appears as a good flood fill is really a super island not connected to any point. Looks pretty and saves etchchant but not likely what you were after. 
> 
> Hope this helps
> Warren

I agree, what he said :)

Re: [Homebrew_PCBs] Re: terminology question:

2009-03-10 by Harvey White

On Tue, 10 Mar 2009 04:45:25 -0000, you wrote:

Click on the unnamed polygon with the name tool and rename it.  It
will redraw and hook to what needs to be connected by the name of the
signal.  Make sure that you set the isolate to control the minimum
spacing to  other traces to allow yourself a space for soldering.
I use 0.024 as a good compromise.

Harvey
Show quoted textHide quoted text
>--- In Homebrew_PCBs@yahoogroups.com, "warrenbrayshaw" <warrenbrayshaw@...> wrote:
>>
>> Piers Goodhew  wrote:
>> >
>> > Next question:
>> > 
>> > If I flood my current design, I get quite a few "Islands" which cannot  
>> > be grounded. Is it a bad idea to flood them as you'll induce all kinds  
>> > of voodoo, or is it perfectly safe?
>> 
>> 
>> In Eagle if you flood-fill a polygon without first specifying the net the flooded polygon should connect to (like GND ) it will create these "islands".
>> 
>> Have a practice with the Eagle Tutorial (page 56 in Version4), and you will see it won't create the islands if you relate the polygon to GND or any other net before flooding it. 
>> 
>> i.e. If an island cannot attach to a net with the same name as that of the polygon then the island isn't created. Just what you wanted.
>> 
>> Additionally if you 'do not' name the polygon then the flood fill will not connect to any points inside the polygon. So what appears as a good flood fill is really a super island not connected to any point. Looks pretty and saves etchchant but not likely what you were after. 
>> 
>> Hope this helps
>> Warren
>
>I agree, what he said :)
>

Re: [Homebrew_PCBs] Re: terminology question:

2009-03-10 by leon Heller

----- Original Message ----- 
Show quoted textHide quoted text
From: "Piers Goodhew" <piers@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, March 09, 2009 10:56 PM
Subject: Re: [Homebrew_PCBs] Re: terminology question:


> Next question:
> 
> If I flood my current design, I get quite a few "Islands" which cannot  
> be grounded. Is it a bad idea to flood them as you'll induce all kinds  
> of voodoo, or is it perfectly safe?

It's best to avoid them, as they can pick up emissions and re-radiate them.

Leon

Re: [Homebrew_PCBs] Re: terminology question:

2009-03-10 by Piers Goodhew

Thanks everyone, these tips are *gold*.

Now that I'm laying out with flooding in mind, I'm rapidly getting rid  
of the islands with judicious nudging anyway.

I might even do the eagle tutorial!

PG
Show quoted textHide quoted text
On 10/03/2009, at 5:56 PM, leon Heller wrote:

> ----- Original Message -----
> From: "Piers Goodhew" <piers@...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Monday, March 09, 2009 10:56 PM
> Subject: Re: [Homebrew_PCBs] Re: terminology question:
>
> > Next question:
> >
> > If I flood my current design, I get quite a few "Islands" which  
> cannot
> > be grounded. Is it a bad idea to flood them as you'll induce all  
> kinds
> > of voodoo, or is it perfectly safe?
>
> It's best to avoid them, as they can pick up emissions and re- 
> radiate them.
>
> Leon
>
>

Re: terminology question:

2009-03-10 by awakephd

--- In Homebrew_PCBs@yahoogroups.com, Piers Goodhew <piers@...> wrote:
>
> Hi All,
> 
> What is the term for the process where your traces are simply  
> "outlined" by etching, and as a result, most of the copper is left on  
> the board, and you presumably use a lot less etchant (and maybe get  
> some 2D RF shielding as well).
> 
> What I'm talking about is used by SparkFun a lot, as in: http://www.sparkfun.com/commerce/images/products/00718-02-L.jpg
> 
> I suppose I have two questions really:
> 
> 1 - what do you call this?
> 2 - is there a handy one-click way to do it in major CAD packages?
> 
> PG
>

For those who use Kicad, this is called "Zones." You can draw one or more zone outlines and use them to put the zone in, OR to exclude the zone. One thing that was not clear in the help files or tutorial is that the zone will connect to the currently highlighted net. If you do not have a net highlighted, it will be an "island." Once I figured that part out, the function works very nicely.

A followup question: For double-sided boards, is it recommended to put a ground flood/zone/fill/whatever on both sides, or just one side? If part of the goal is to save etchant, then it seems that a flood on both sides would be good; if not connected to ground on both sides, what should it be connected to? Would making one side ground and one side Vcc be good practice??

Move to quarantaine

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