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Component Clearance rule and mechanical layers

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  • Component Clearance rule and mechanical layers

    Hi all!

    In my company when designing footprints, we use dedicated mechanical layers describing some of footprint design details: footprint designer, checker, date of design, copyrights etc... So I in every footprint I have such group of additional mechanical layers.

    When I'm working on placement in Altium, I often have Component Clearance DRCs showing up. It occurs, that in many cases text in those layers is bigger than etch or assembly layer in footprint (e.g. in small resistors - size of text is bigger than resistor itself) and is overlapping on other components. I need to move these texts or decrease their size, but it's so big waste of time.

    How can I just adjust Component Clearance rule, so it won't be activated when one of mentioned mechanical layers appears in area of other footprint? For example text on layer "M13 - Design date" of component MH3 is overlapping J6 footprint (see screenshot).

    I tried to change this rule for:

    First object:
    All AND ( NOT ( OnLayer('M11 - Designed by') OR OnLayer('M12 - Approved by') OR OnLayer('M13 - Design Date') OR OnLayer('M14 - Copyrights') ) )

    Second object: the same as first object

    Or other:
    First object:
    All AND ( NOT ( OnLayer('M11 - Designed by') OR OnLayer('M12 - Approved by') OR OnLayer('M13 - Design Date') OR OnLayer('M14 - Copyrights') ) )

    Second object: All

    But none of them seem to be working.
    Attached Files

  • #2
    Either add 3D model to the components or
    'ignore' the components (fiducials, mounting holes, etc.)
    Use a component class for instance.

    By the way, I put such parameters in the footprint description. Add semicolon ; to separate, <ParameterName>=<Value>.
    Also made a marco that extracts the parameters and 'adds' them to the schematic symbol. DfM post update.


    • #3
      Probably not the answer you're looking for, but if you convert the meta data from text strings on mechanical layers to component parameters, then for each parameter, you can select whether it appears or not (parameters have the eye icon, text strings do not). When it doesn't appear, it doesn't interfere, like a designator.

      Meanwhile, there should be a rule syntax that lets you exclude the meta data from checking.🤔


      • #4
        The problem is that I have such texts in all footprints. I can ignore fiducials, MHs, TPs, but what about the other components?

        Interesting thing is that there are 3D bodies in every footprint. Even in mounting holes but the rule checks mechanical layers too.

        You described nice tricks with parameters. It would be useful if I could turn on and off such texts as parameters, but I don't see this eye icon in PCB editor. I know it is working for schematic symbols, but for PCB - I don't see it (looking in properties -> parameters).

        I'm afraid that the solution with parameters won't work for me in the long run. In my company the footprints are originally created in Cadence and then transferred to Altium (many years working in Cadence only and now starting using Altium for other customers). In Cadence we have such additional layers describing footprints and it is expected to have them in Altium too. I probably have more problems than use from it, but I can do nothing about it. In the end I need to figure out a workaround of these mechanical layers.


        • #5
          Now I see I was wrong! I deleted 3D Body from mounting hole and probably that was the reason why the violation was created.


          • #6
            Oh, yeah. If you were tuning the query language of electrical clearance rules when the rule being violated was component clearance, that would explain why rule changes weren't helping.


            • #7
              No, I did change component clearance rule, not electrical clearance. What I mean is that I had removed 3D Bodies from violating components. Then I moved on to some other works and suddenly noticed that I have component clearance DRCs. No wonder - if there are no 3D Bodies (and silkscreen btw), then component clearance rule doesn't work as I would expect.


              • #8
                Yes, you will get different results if your footprints have 3D models and without them.