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how to define non-signal (ground) layer in v7.2

Former Member

Using the standard version, with a top/bottom and 3 other routing inner layers, a very split power plane layer, how do I define a non-signal inner ground layer that can be polygon poured and get anti-pads around non-ground signal vias during ratsnest?

Stackup will be with only 6 signal layers (if you count the power plane):

1) Top with SMT, low frequency traces, and some high speed routing traces

2) desired inner ground layer

3) inner low frequency routing layer

4) Power plane

5) a 2nd copy of the inner ground layer

6) inner high frequency routing layer

7) inner high frequency routing layer

8) Bottom with SMT components...

Note that I'm going to be using TH vias rather than buried or blind vias, as well as some TH connectors

  • 0 in reply to Former Member

    On 30/04/15 03:39, Bruce Mellen wrote:

    I'm already using all 6 signal layers for

    routing and need a separate dedicated ground/supply plane that just

    accepts polygons and has clearance around the vias when doing a

    ratsnest.

     

    So in other words, you have a license for doing six-layer boards and

    you're hoping for a cheat that will allow you to do a seven layer board

    with it. Sorry, Eagle won't do that.

     

  • 0 in reply to autodeskguest

    Then why do they advertise it will do 6 signal layers rather than board layers?  I thought ordinary Gnd/power planes would not count in the 6.  Hmmmmmm.......

    I'm disappointed that It has taken since April 10th to get this question answered, some answers taking me down blind alleys in the meantime and apparently not reading the original question.

    Thank you for now making it clearer from a technical perspective. 

    Marketing needs to do some better work in their product description and helps, though.

  • 0 in reply to autodeskguest

    Warren,

    Unfortunately I am not looking for a duplication of one of the 6 layers I want for routing traces and multiple voltages.  I'm aware I can duplicate a layer when putting together a set of Gerbers.

    It appears Cadsoft has promulgated the concept of Ground and constant voltages as signals just because it is entered into a field called Signal Name.  That does not make anything on a dedicated ground plane, a signal.  I go by the definition of signal as something that conveys information....  there are several online references to the term as used in EE.

    I would suggest Cadsoft change it advertising to list 6 layer boards rather than 6 signal layers.  If a person can get away with duplicating a layer, maybe they can get a 7th for free.

     

    Thanks for listening to my view.

  • 0 in reply to Former Member

    On 30/04/15 20:25, Bruce Mellen wrote:

    It appears Cadsoft has promulgated the concept of Ground and constant

    voltages as signals just because it is entered into a field called

    Signal Name.

     

    No, they haven't, it's a universally accepted industry norm. You're the

    one who's being disingenuous for nefarious purposes.

     

  • 0 in reply to Former Member

    Bruce Mellen wrote on Thu, 30 April 2015 12:25

    It appears Cadsoft has promulgated the concept of Ground and constant

    voltages as signals just because it is entered into a field called Signal

    Name.  That does not make anything on a dedicated ground plane, a

    signal.

     

    You poor kid, you've put a lot of effort into something that didn't turn

    out the way you had hoped.  I feel bad for you...

    --

    Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

     

  • 0 in reply to autodeskguest

    Whomever you are as a Cadsoft Guest, don't accuse me of either.  It is untrue.  You need to be polite.

    I disagree it (a ground layer or even another supply layer) is considered a signal by the industry in that it does not carry information.

    If Cadsoft wants to be as specific as saying 6 signal layers, and I understand they used to separately offer supply layers, then there should be some accommodation to continue to handle supply layers - which is what I'm asking for.

     

    Signal (electrical engineering)

     

    From Wikipedia, the free encyclopedia

     

    http://en.wikipedia.org/wiki/Signal_(electrical_engineering)#mw-headhttp://en.wikipedia.org/wiki/Signal_(electrical_engineering)#p-search

     

    This article is about signals in electrical engineering.

     

    A signal as referred to in communication systems, signal processing, and electrical engineering "is a function that conveys information about the behavior or attributes of some phenomenon".[1] In the physical world, any quantity exhibiting variation in time or variation in space (such as an image) is potentially a signal that might provide information on the status of a physical system, or convey a message between observers

    All About Circuits: "A signal is any kind of physical quantity that conveys information."

    Sparkfun:

    "Define: Signals

    Before going too much further, we should talk a bit about what a signal actually is, electronic signals specifically (as opposed to traffic signals, albums by the ultimate power-trio, or a general means for communication). The signals we’re talking about are time-varying “quantities” which convey some sort of information. In electrical engineering thequantity that’s time-varying is usually voltage (if not that, then usually current). So when we talk about signals, just think of them as a voltage that’s changing over time."

  • 0 in reply to Former Member

    Hi,

    I think two, four and 6-layer PCB layout bundles are pretty standard. In electronic engineering the word 'signal' has a meaning, but in the PCB layout engineering world it is already (for decades?) very clear that software is offered typically licensed in two, four, six and unlimited number of copper layers. Where they are licensed in such a manner (as opposed to pin count for example) I don't think unlimited power planes are available for the 2, 4 and 6 layer offerings. I could be wrong.

    Here is a Cadstar page which offers the same number of layers, as does EasyPC for their routing product. These are just two random examples.

  • 0 in reply to shabaz

    Thank you for the further perspective.

    I have only been in the PCB Layout engineering world for a couple years and now getting into more than a couple board layers and BGA. 

    I obtained the "6 signal layer" license with the expectation of additional "supply layer"s that I saw referenced, since it used the term signal layer rather than copper or board layers.

  • 0 in reply to Former Member

    Bruce Mellen wrote on Thu, 30 April 2015 17:43

    I obtained the "6 signal layer" license with the expectation of

    additional "supply layer"s that I saw referenced, since it used the term

    signal layer rather than copper or board layers.

     

    In all your pedantry, I think you're forgetting one thing.  Just because

    you know whether there is a signal on a copper layer doesn't mean that

    any CAD software "knows" whether there is a signal or not.  You can add a

    signal to something labeled "ground" as well as something labeled "+5V" if

    you want.  I don't see how you came up with the assumption that you could

    have as many copper layers as you wished as long as you knew there was no

    signal on them...

     

    My personal interpretation  of the literature is that CADSOFT provides 6

    signal layers as opposed to x number of graphic layers or dimension layers,

    etc.  IANAL

    --

    Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

     

  • 0 in reply to autodeskguest

    Reason: because supply layers have been described out here in addition to the signal layers.  Supply layers, which I understood would accept polygons but not traces.  I apparently misinterpreted, but Eagle could have been (or be) implemented as such:  Not allowing routing of signals on layers other than 6 chosen would effectively limit the software to 6 signal layers and additional desired supply layers (poured power and ground planes) that one can afford to have manufactured.