AVR-Chat

I'll need to be laying out some boards for signal conditioning and I/O (optos,
relays, etc.) and I'd like them to have a professional look.  One offs for my
own consumption not for sale.

I've downloaded AutoTrax.  Nice program, but I don't think I can justify the
cost (after the free period) for the few boards I'd be doing.

Does anyone know of any layout tools available on the net that might be
suitable.  Possibly limited to x layers or y parts count?  I think I can live
with limiting it to double-sided possibly w/jumpers/cross connects.

For the few I'll be doing initially I'd expect to etch them myself and use my
(home conversion) CNC mill to drill them (I can use Ecelon <sp?> drilling
files).

I would like to also have the ability to send off drawing files, etc. to a
prototyping house if board complexity/quantity warrants.

For future use:  If you needed one or two boards made (possibly double sided at
most) what web resource would you use?

I can see how I would expose the boards using overheads printed on a laser
printer and photo-etch but how would one do the equivalent of silk-screening for
a home etched board?

Cheers,

Chuck Hackett
"Good judgment comes from experience, experience comes from bad judgment"
7.5" gauge Union Pacific Northern (4-8-4) 844
http://www.whitetrout.net/Chuck

----- Original Message ----- 

From: Chuck Hackett
To: AVR-Chat@yahoogroups.com
Sent: Sunday, October 24, 2004 10:29 PM
Subject: [AVR-Chat] PCB Routing/Layout software


I'll need to be laying out some boards for signal conditioning and I/O 
(optos,
relays, etc.) and I'd like them to have a professional look.  One offs for 
my
own consumption not for sale.

I've downloaded AutoTrax.  Nice program, but I don't think I can justify the
cost (after the free period) for the few boards I'd be doing.

Does anyone know of any layout tools available on the net that might be
suitable.  Possibly limited to x layers or y parts count?  I think I can 
live
with limiting it to double-sided possibly w/jumpers/cross connects.

For the few I'll be doing initially I'd expect to etch them myself and use 
my
(home conversion) CNC mill to drill them (I can use Ecelon <sp?> drilling
files).

I would like to also have the ability to send off drawing files, etc. to a
prototyping house if board complexity/quantity warrants.

For future use:  If you needed one or two boards made (possibly double sided 
at
most) what web resource would you use?

I can see how I would expose the boards using overheads printed on a laser
printer and photo-etch but how would one do the equivalent of silk-screening 
for
a home etched board?

I use Pulsonix for board design, it's excellent but rather expensive: 
http://www.pulsonix.com

The free demo (100 pins max.) might do what you want.#

Easy-PC (same company) is more suitable for hobbyists: 
http://www.numberone.com

I make single-sided PCBs at home by printing the artwork onto tracing paper 
and using that to expose resist-coated boards using a home-made UV exposure 
unit. Development is in sodium hydroxide solution and they are etched in 
warm ferric chloride solution.

You don't really need silk-screen, I assemble my home-made PCBs by referring 
to the layout on the screen.

Leon

Eagle is quite popular.

Thanks for the replies.  I'm checking out Eagle (http://www.cadsoft.de) now ...

Cheers,

Chuck Hackett
"Good judgment comes from experience, experience comes from bad judgment"
7.5" gauge Union Pacific Northern (4-8-4) 844
http://www.whitetrout.net/Chuck

If you want fast and easy,  google WinQCAD.

It outputs gerbers and CNC files.

Probably the fastest to learn, espically as compared to Eagle.


But, it will not win any Olympic medals.   There are many programs 
that will out-do it, but it offers all the basics.

Another one to look at is TARGET.

The toner transfer is the easy way to do it at home, but be careful 
about the learing curve.  you will waste some boards.

Double sided is easy if you align the marks on the papers and then 
slide the board between.

Drilling is best done with CNC, and if you have not done some, 
considder two approaches.

#1, use only 0.1" pin spaceing.  Then buy a perf board and use that 
as an alignment for drill holes.

Or, buy a machine tool socket and drill out all the pins.  then drill 
Pin #1 on your IC, then insert a blank drill and the drilled out 
socket and presto ! instant alignment.

For more on home brew PCB's vist the yahoo group
http://groups.yahoo.com/group/Homebrew_PCBs

Dave

--- "Chuck Hackett" <egroupscdh@W...> wrote:
> Does anyone know of any layout tools available on the net that
> might be suitable.

I use Sprint-Layout, it's very quick:

http://www.abacom-online.de/uk/html/sprint-layout.html

Jeremy,

--- In AVR-Chat@yahoogroups.com, "Chuck Hackett" <egroupscdh@W...> 
wrote:

> I'll need to be laying
> out some boards ...

If you can keep the size down to half-eurocard, the free version of 
Eagle is worth a look. It is a professional quality tool and though 
it won't be as easy to learn as some you're very unlikely to run into 
a defect or missing feature. All ECROS Technology products are made 
using Eagle (not the free one, of course).

Unless you are on the tightest budget, I suggest having proper double 
sided plated through PCBs made. If you do without solder mask and 
silkscreen, you can get the price down.  I use Bare-Bones PCB 
(www.barebonespcb.com), which is a division of Advanced Circuits, for 
my prototypes. The quality is excellent and you get a free packet of 
microwave popcorn. The only downside is that they pester you a little 
bit for production work but you can just ignore that.

Graham.

> 
> --- "Chuck Hackett" <egroupscdh@W...> wrote:
> > Does anyone know of any layout tools available on the net that
> > might be suitable.
> 

Another one is CirCad.  It's at http://www.holophase.com/

The free program demo won't produce Gerber or Postscript files but it will 
allow you to print your pattern.  I've used a screen capture program to 
take the pattern displayed on the screen and convert it to a graphics file 
which I can turn into a negative with a graphics program.

By the way, I've described this on several ham radio groups I'm on, but I 
have a routine for making pc boards that has been successful for me for 
years.  I started out making negative pc board patterns with Kodalith in 
the darkroom, but lately I've been designing the patterns with Coreldraw 
or making a negative from an image file and printing on a transparency 
sheet on a laser printer.  Depending on the printer and the transparency 
film used, you may have to touch up the dark areas with a marker. I 
prepare a board for coating with Datak ER-71 photoresist (this is a 
negative-acting resist similar if not identical to the old Kodak KPR) and 
coat it according to the instructions. I let it dry at least overnight.  
Then I put the negative over the pc board in a contact printer and expose 
to bright sunlight for about 2 - 2 1/2 minutes.  I develop in Datak ER-8 
developer for about a minute and inspect the board.  Sometimes a bit of 
touch-up needs to be done on the photoresisit with a fine-tipped marker. I 
then etch the board.

If you have a very detailed pc board pattern with fine lines, make the 
transparency "flipped" so it is correct when the side that actually has 
toner is in contact with the pc board when you expose it.  I've been 
making boards for microwave circuits up to 10 GHz with this method with 
excellent results.  I'm about to try it with some 24 GHz circuits.

Zack

> I use Bare-Bones PCB
> (www.barebonespcb.com), which is a division of Advanced Circuits, for
> my prototypes. The quality is excellent and you get a free packet of
> microwave popcorn. The only downside is that they pester you a little
> bit for production work but you can just ignore that.


I can say that I have used Advanced Circuits also. They do quality work 
and have a good student discount program. Never got the popcorn though. :-/

-jr

Thanks to all for the replies to my search for layout software.  I'm in the
process of becoming familiar with Eagle.  I like the fact that I can start with
the freeware version and upgrade later if my needs grow without having to learn
a new program.

Cheers,

Chuck Hackett
"Good judgment comes from experience, experience comes from bad judgment"
7.5" gauge Union Pacific Northern (4-8-4) 844
http://www.whitetrout.net/Chuck