Eagle: How to convert a 2 layer board to 4 layer?

On 10/21/2016 10:11 AM, Dave Chambers wrote:

I have a 2 layer design in Eagle 7.7.0

I want to convert it to 4 layer - basically insert 2 inner layers (power, ground).

Can this be done, and if so, how is it done?

 

Thanks,

-Dave

 

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Hi Dave,

I hope you're doing well. The short answer is:

1. Click on DRC

2. Go to the layers tab

3. Change the setup equation from (1*16) to:

(12+1516)

4. Click Apply

5. Click Cancel

The long answer:

Above I have given you one of the simplest 4 layer setups. It does not

enable blind or buried vias, so if you need those the above

configuration won't help.

For more information, please see section 6.5 of the EAGLE manual.

hth,

Jorge Garcia

OK, that helps a bit.

played with the layer setup editor, and I understand what "*" and "+" mean, but the ascending rule is a bit odd.

I want to be able to connect 1 and 2, 1 and 3, 1 and 4. No need to connect 2 or 3 or 4 to each other.

How do I specify that?

On 10/21/2016 12:28 PM, Dave Chambers wrote:

OK, that helps a bit.

played with the layer setup editor, and I understand what "*" and "+" mean, but the ascending rule is a bit odd.

I want to be able to connect 1 and 2, 1 and 3, 1 and 4. No need to connect 2 or 3 or 4 to each other.

How do I specify that?

 

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Hi Dave,

It is important to understand that you likely don't need to have to many

different via configurations. The default through hole via, can reach

all the layers. EAGLE will automatically isolate the via from any layers

it is not supposed to connect to.

Using blind and buried vias increases the cost of the board

substantially. So unless you have a super tight layout I would

discourage their use.

hth,

Jorge Garcia

Excellent info - thanks.

So then which setup is the "standard" 4-layer rule:

(1*2)+(15*16)     (2 cores with prepreg in between)

or

(1+2)+(15+16)  (3 cores)

-Dave

On 10/21/2016 03:25 PM, Dave Chambers wrote:

Excellent info - thanks.

 

So then which setup is the "standard" 4-layer rule:

(12)+(1516)     (2 cores with prepreg in between)

or

(12)(15+16)  (3 cores)

The stack-up depends entirely on who is making the boards, and whether

you're looking for a quick-turn prototype or making a large production run.

Advanced Circuits advertises their quick-turn 0.062" 4-layer board as

being two cores with prepreg between them. Without blind/buried vias

this is properly entered as "(12+1516)".

However, AP Circuits, Sunstone, PCB-Pool, and OshPark stack-ups are one

core with prepreg layers added to either side. Without blind/buried

vias, this is properly entered as "(12*1516)".

If you're not doing blind or buried vias it doesn't make much difference

which way you enter the stack-up into Eagle. If you ARE doing

blind/buried, the pluses, asterisks, and extra parentheses tell Eagle

where you can and can't place vias between the various layers.

On 10/21/2016 03:25 PM, Dave Chambers wrote:

Excellent info - thanks.

 

So then which setup is the "standard" 4-layer rule:

(12)+(1516)     (2 cores with prepreg in between)

or

(12)(15+16)  (3 cores)

The stack-up depends entirely on who is making the boards, and whether

you're looking for a quick-turn prototype or making a large production run.

Advanced Circuits advertises their quick-turn 0.062" 4-layer board as

being two cores with prepreg between them. Without blind/buried vias

this is properly entered as "(12+1516)".

However, AP Circuits, Sunstone, PCB-Pool, and OshPark stack-ups are one

core with prepreg layers added to either side. Without blind/buried

vias, this is properly entered as "(12*1516)".

If you're not doing blind or buried vias it doesn't make much difference

which way you enter the stack-up into Eagle. If you ARE doing

blind/buried, the pluses, asterisks, and extra parentheses tell Eagle

where you can and can't place vias between the various layers.

"(12*1516)"  (w/o quotes) is not a valid setup string.

Eagle complains that layer 1516 is an invalid layer. Need some sort of separator between each number.

I'm using Sunstone, which has core between 2 and 15, then prepreg between 1&2 and 15&16

So, for the simplest stack-up, that would be (1+2*15+16)

That isn't really what I initially was looking for, but as @JorgeGarcia said, Eagle will automatically connect the layers, so take that as an answer.

Thanks to all for their input & patience.

Am 22.10.2016 um 20:32 schrieb Dave Chambers:

"(12*1516)"  (w/o quotes) is not a valid setup string.

Eagle complains that layer 1516 is an invalid layer. Need some sort of separator between each number.

 

I'm using Sunstone, which has core between 2 and 15, then prepreg between 1&2 and 15&16

So, for the simplest stack-up, that would be (12*1516)

That isn't really what I initially was looking for, but as @JorgeGarcia said, Eagle will automatically connect the layers, so take that as an answer.

 

Thanks to all for their input & patience.

 

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Hi Dave,

what do you think about this? ((12)*(1516))

Freundliche Grüße / Kind regards

Friedrich

-

... use NNTP://news.cadsoft.de and a

functional news reader like Thunderbird!

On 10/22/2016 02:32 PM, Dave Chambers wrote:

"(12*1516)"  (w/o quotes) is not a valid setup string. Eagle

complains that layer 1516 is an invalid layer. Need some sort of

separator between each number.

 

I'm using Sunstone, which has core between 2 and 15, then prepreg

between 1&2 and 15&16 So, for the simplest stack-up, that would be

(12*1516) That isn't really what I initially was looking for, but

as @JorgeGarcia said, Eagle will automatically connect the layers, so

take that as an answer.

I'm confused. I don't see any difference between what I wrote and what

you say works. Both read "(12*1516)" on my screen and is exactly what

I've used with Eagle versions 6 and 7 (w/o the quotes, of course) for

production by PCB Pool.

If you want through vias that connect to all layers, this works just

fine. It's when you get into blind and buried vias that only connect

certain layers that things get interesting and the Eagle layer setup

really becomes critical.

On 10/22/2016 10:50 PM, Reece R. Pollack wrote:

On 10/22/2016 02:32 PM, Dave Chambers wrote:

"(12*1516)"  (w/o quotes) is not a valid setup string. Eagle

complains that layer 1516 is an invalid layer. Need some sort of

separator between each number.

 

I'm using Sunstone, which has core between 2 and 15, then prepreg

between 1&2 and 15&16 So, for the simplest stack-up, that would be

(12*1516) That isn't really what I initially was looking for, but

as @JorgeGarcia said, Eagle will automatically connect the layers, so

take that as an answer.

 

I'm confused. I don't see any difference between what I wrote and what

you say works. Both read "(12*1516)" on my screen and is exactly what

I've used with Eagle versions 6 and 7 (w/o the quotes, of course) for

production by PCB Pool.

 

If you want through vias that connect to all layers, this works just

fine. It's when you get into blind and buried vias that only connect

certain layers that things get interesting and the Eagle layer setup

really becomes critical.

 

I suspect the problem is the Element14 web interface. It interprets the

asterisks in newsgroup postings as "change to bold" indicators and

doesn't show them. The EagleCentral.ca web interface shows the posts

properly.

Is the Element14 web interface going to go away now that Farnell sold

CadSoft to Autodesk? Please?

> the Element14 web interface interprets the asterisks in newsgroup postings as "change to bold"

Yes, that would explain it - I've noticed the bold/italics and was puzzled by them.

So all along you've been saying "1 star 1 star 15 star 16" ?

On 10/23/2016 10:57 AM, Dave Chambers wrote:

the Element14 web interface interprets the asterisks in newsgroup

postings as "change to bold"

Yes, that would explain it - I've noticed the bold/italics and was

puzzled by them. So all along you've been saying "1 star 1 star 15

star 16" ?

For Sunstone (prepreg - core - prepreg), I'd use "1 plus 2 star 15 plus

16", which is exactly what

you surmised.

For Advanced circuits (core - prepreg - core), "1 star 2 plus 15 star

16" is correct.

As Jorge pointed out, if you're using through vias it's mostly

irrelevant. And unless you have real need to use blind or buried vias,

through vias are what you want to use.