Single Side with wire link top layer ?

On Wed, 06 Aug 2008 19:26:52 +0200, Anton Schoultz

<AntonSchoultz@gmail.com> wrote:

Is there a way to get Eagle to auto route as a single sided pcb (one

layer) with straight wire links as the "top layer" ?

I can get single sided board easily enough by setting top layer to "N/A"

I have tried fiddling with the routing parameters to try and get the top

layer as straights only, but need to minimize no of "track" on the top

layer.

 

 

The closest that I can come at this point is to auto route single layer,

then manually go and add tracks and vias for the wire links - a painful

process.

 

I am no expert but how about a zero-ohm resistor.  Eagle is happy and

you put anything in the resulting board, including a hunk of wire.

John

Anton Schoultz wrote:

Is there a way to get Eagle to auto route as a single sided pcb (one

layer) with straight wire links as the "top layer" ?

I can get single sided board easily enough by setting top layer to "N/A"

I have tried fiddling with the routing parameters to try and get the top

layer as straights only, but need to minimize no of "track" on the top

layer.

 

 

The closest that I can come at this point is to auto route single layer,

then manually go and add tracks and vias for the wire links - a painful

process.

 

Using 4.16r2.

 

Thanks in advance

Anton Schoultz

Generally, on all but the simplest circuits, to produce a board with good

immunity and emissions specs on a single sided layout requires very careful

routing, and I would never let an autorouter near a single (or double sided)

layout.  Routing of gnd/current return traces is always critical for single

and double sided layouts.

Every time I see someone looking to autoroute single and double sided PCB's

I really feel they are missing out on actually learning anything or showing

any understanding about good PCB layout.

Having said that I'd recommend your first approach. Route as a double sided

board with a high cost factor for the top (wire link) layer.

Just because the autorouter puts a bend in the wire doesn't mean you have

to.  There is always a straight line between the start and end points- or do

you only want wires in the vertical and horizontal planes?  What is you

criteria for only having straight lines on the top layer and why is it so

important?

cheers

David

David Moodie wrote:

Anton Schoultz wrote:

Is there a way to get Eagle to auto route as a single sided pcb (one

layer) with straight wire links as the "top layer" ?

I can get single sided board easily enough by setting top layer to "N/A"

I have tried fiddling with the routing parameters to try and get the

top layer as straights only, but need to minimize no of "track" on the

top layer.

 

 

The closest that I can come at this point is to auto route single

layer, then manually go and add tracks and vias for the wire links - a

painful process.

 

Using 4.16r2.

 

Thanks in advance

Anton Schoultz

 

Generally, on all but the simplest circuits, to produce a board with

good immunity and emissions specs on a single sided layout requires very

careful routing, and I would never let an autorouter near a single (or

double sided) layout.  Routing of gnd/current return traces is always

critical for single and double sided layouts.

 

Every time I see someone looking to autoroute single and double sided

PCB's I really feel they are missing out on actually learning anything

or showing any understanding about good PCB layout.

 

Having said that I'd recommend your first approach. Route as a double

sided board with a high cost factor for the top (wire link) layer.

 

Just because the autorouter puts a bend in the wire doesn't mean you

have to.  There is always a straight line between the start and end

points- or do you only want wires in the vertical and horizontal

planes?  What is you criteria for only having straight lines on the top

layer and why is it so important?

 

cheers

 

David

Hi David

I thought Id like to pop in to this topic even though you have said it all.

But to clearify why some people wants to make single sided boards is the

simple fact that many hobbyist starts right here either by using

euroboards or by etching ones own single sided board. Then one can not

always ensure that one is able to route everything on one single side,

but one would be required to do some strapping. If the auto router can

give you the least amount of strapping possible (with straight lines

which looks most pretty on the component side) then why not.

For hobyist and some prototype makers and "small budget indeed" hobyist

the best gift would actually be an autorouter and grid setup feature

which simulates an euroboard. Like it or not. For companies or advance

hobyist it might look like a vast but the need is still there for

someone. Thats was where I started my self before gradually the

knowledge and selftrust grown to be able to make professional looking

products/layouts.

I do not think they are "missing out" on the learning process, but

sometimes one need to learn to walk (i.e. make some electronics that

works) before one can climb the mountains (i.e. making perfect PCB

layouts with perfect electronics). And sometimes the first steps takes

longer time to learn than learning to run when you already knows how to

walk.

I am sure Anton know aboute these facts that for a good comercial

product every inch of your schematics and PCB must have been

investigated several times to ensure the best possible product but

sometimes "quick and dirty" is more than you ask for.

breg

Vidar(Z)

Vidar (Z) wrote:

David Moodie wrote:

Anton Schoultz wrote:

Is there a way to get Eagle to auto route as a single sided pcb (one

layer) with straight wire links as the "top layer" ?

I can get single sided board easily enough by setting top layer to "N/A"

I have tried fiddling with the routing parameters to try and get the

top layer as straights only, but need to minimize no of "track" on

the top layer.

 

 

The closest that I can come at this point is to auto route single

layer, then manually go and add tracks and vias for the wire links -

a painful process.

 

Using 4.16r2.

 

Thanks in advance

Anton Schoultz

 

Generally, on all but the simplest circuits, to produce a board with

good immunity and emissions specs on a single sided layout requires

very careful routing, and I would never let an autorouter near a

single (or double sided) layout.  Routing of gnd/current return traces

is always critical for single and double sided layouts.

 

Every time I see someone looking to autoroute single and double sided

PCB's I really feel they are missing out on actually learning anything

or showing any understanding about good PCB layout.

 

Having said that I'd recommend your first approach. Route as a double

sided board with a high cost factor for the top (wire link) layer.

 

Just because the autorouter puts a bend in the wire doesn't mean you

have to.  There is always a straight line between the start and end

points- or do you only want wires in the vertical and horizontal

planes?  What is you criteria for only having straight lines on the

top layer and why is it so important?

 

cheers

 

David

 

Hi David

 

I thought Id like to pop in to this topic even though you have said it all.

 

But to clearify why some people wants to make single sided boards is the

simple fact that many hobbyist starts right here either by using

euroboards or by etching ones own single sided board. Then one can not

always ensure that one is able to route everything on one single side,

but one would be required to do some strapping. If the auto router can

give you the least amount of strapping possible (with straight lines

which looks most pretty on the component side) then why not.

 

For hobyist and some prototype makers and "small budget indeed" hobyist

the best gift would actually be an autorouter and grid setup feature

which simulates an euroboard. Like it or not. For companies or advance

hobyist it might look like a vast but the need is still there for

someone. Thats was where I started my self before gradually the

knowledge and selftrust grown to be able to make professional looking

products/layouts.

 

I do not think they are "missing out" on the learning process, but

sometimes one need to learn to walk (i.e. make some electronics that

works) before one can climb the mountains (i.e. making perfect PCB

layouts with perfect electronics). And sometimes the first steps takes

longer time to learn than learning to run when you already knows how to

walk.

 

I am sure Anton know aboute these facts that for a good comercial

product every inch of your schematics and PCB must have been

investigated several times to ensure the best possible product but

sometimes "quick and dirty" is more than you ask for.

 

breg

Vidar(Z)

Vidar hit the nail on the head. I am decidedly in the "budget hobbyist"

category. The board that I want to put together is a prototyping

board for a PIC processor - with some additional circuitry such as shift

register, bcd->7seg, and 1-of-10 low so that I can experiment with

driving LCD module using two or three I/O lines (and shift register) to

play with driving an 8 digit mux'd numeric led  display etc. later I'd

like to set up some proto-pcb for experiments with I2C etc. I have had

PCB made which are laid out like a breadboard - a little better than

using veroboard. I DO appreciate that some PCBs need a lot more care

and attention, to the extend of ensuring that all data paths are the

same length to prevent jitter at high clock frequencies etc - but I'm

not building a motherboard for a ?GHz cpu. While the insides of the pic

run at 6Mhz, the outside/real world signals will be in the order of KHz.

An auto-router that can do a half way decent routing job which minimizes

the wire straps (both length and number of wires) would be great for me,

and I dare say, many other hobbyists. The direction of the top wires is

not critical, but ideally they should be simple straight links, without

junctions iow point-to-point only, and not using component leads as vias.

I have got reasonable (but not great) results using direct transfer of

laser print-out. Have to use wide tracks and large spacings - but at

least I can then do it myself. My next step up (better PCB) is to print

the negative on overhead transparency using my ink-jet (sometimes

over-print to thicken the ink) - then have a board done photographically

from my 'negative'

The cost of having a real negative made from a print out is actually

more than having the board done from the negative! In in many cases this

is even more expensive than the cost of the parts that go on the pcb!

I have made a perfectly good pcb for a binary alarm clock using a pic -

has been working sweetly for over four years now.

On Thu, 7 Aug 2008, Anton Schoultz wrote to us saying :

I have got reasonable (but not great) results using direct transfer of

laser print-out. Have to use wide tracks and large spacings - but at

least I can then do it myself.

I do home etch from a laser printer using transparency paper (not the

plastic clear stuff but some slightly cloudy paper designed specially

for photo etching). Just print to the paper then expose the board

against that in my UV box. I can get track widths down to .016" and gaps

to 0.012" without any difficulty.

If I want to go finer than that (or double sided or anything) I'll

generate Gerbers and order a board from my friendly not-so-local PCB

house - the cost is really quite reasonable and you get proper PTH with

solder mask and silk screen.

--

Rob Pearce                       http://www.bdt-home.demon.co.uk

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