3 Replies Latest reply on Apr 9, 2015 10:42 AM by brucen

    Geometry Heights


      Hello All,


      What determines what PADS Layout uses as an attribute to form a 3D Geometry Height view?  Our library decals are built with a shape on "Assembly Drawing Top" which is the actual size of the component.  We also have a shape on Layer 20 that encloses the entire outer most feature of the component, be it SMD pads/PTH or the body outline.  This is used as a placement guide when placing parts.  This is given a slight margin of clearance to the actual shape.  PADS Layout uses this shape on Layer 20 to make the 3D view.  The problem is that it's larger than the actual part and it may show parts overlapping.  How can I change what is used for 3D to the Assembly Drawing shape, which is more representative of the actual size?





        • 1. Re: Geometry Heights

          Hi Bruce


          In the IDF Export dialog you can select which layer to use for IDF Export.



          • 2. Re: Geometry Heights

            You can also define the preferred layer in powerpcb.ini


            From MG518767 (it loosk like this is from the old Mentor site)

            Component outline is searched on layers in following order:

            1. layer defined in ini in 3D_Shape_Layer entry, section Graphics (only if value provided there is a valid layer number)
            2. layer 25 (125)
            3. top associated assembly layer
            4. top layer
            5. <All Layers>
            6. layer 20 (120)

            To specify silkscreen as a 3D-Shape_Layer in ini-file

            Open powerpcb.ini file and add 3D_shape_Layer under [Graphics] section.

            3D_Shape_Layer  = <layer_number>



            Here are my notes on the subject (a summary of thread 16213 on this site):


            Notes from Mentor blog (modified) about body to body clearance


            On Layer 26, build your silkscreen outline.  Use 8 mils, 10 mils, whatever you like, don't worry about part size, make it pretty.


            On Layer 19 ("3D Outlines") , build an actual size (maximum for all alternate parts) part outline.  Use a 1 mil line width.  This one is for assembly drawings, output to IDF.  It must be a single closed polygon.


            On Layer 20 ("Placement Courtyard"), copy the Layer 19 shape (1 mil), and if you need additional clearance around the part for pick and place or ICT considerations, add it here.


            Set the Body to Body clearance rule to whatever you need, run your Verify Design with all outline layers except Layer 20 turned off.  Now here's the trick: set up your Clearance Checking to check Placement Outline, not Body to Body (that's right, it doesn't really make sense).

            • 3. Re: Geometry Heights

              Thanks Klaus-  This looks good when I do the 3D preview.  I've sent check files off to the mech designer, waiting to hear what he says.