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 How does the Shape's Clearance work for PTH and Nn-PTH? 

Last post Thu, Jan 18 2007 12:31 AM by archive. 2 replies.
Started by archive 18 Jan 2007 12:31 AM. Topic has 2 replies and 646 views
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  • Thu, Jan 18 2007 12:31 AM

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    How does the Shape's Clearance work for PTH and Nn-PTH? Reply

    How does the Shape's Clearance work for PTH and Non-PTH?

    For example, I have two though hole, one is plated, the other is non-plated:

    Unit:mm
                     Plating:           Drill:     Top Pad:                    Top Anti Pad:
    Pad1:        Plated            1           circle1.5                      1.9
    Pad2:        Non-Plated     1           circle 1  (unuseful)      3.0 

    Now, there is a Net Shape arround them, the shape has a Net Spacing Type property with 0.15mm(6mil) for Shape to Pin.
    If the Clearance setting sets Thru pin: DRC and Oversize value:0. The radius of Void around Pad1 is equal to 0.9mm(0.5+0.25+0.15), that means the spacing between Shape and drill edge is 0.4mm. The spacing to pad edge is 0.15mm. For Pad2. the radius of Void is 0.65mm and spacing to drill is 0.15mm.
    If use the setting:
    Thru pin: Thermal/anti and Oversize value:0. The Void radius arround Pad1 is 0.95mm. The spacing to drill is 0.45mm,  And spacing to pad edge is 0.2mm. For Pad2 void radius is 1.5mm. The spacing is and 1mm.

    Now, my problem is:
    When I use DRC clearance, the spacing for  Non-Plated pad is not correct. and use Thermal/anti, the spacing for Plated pad is larger than my constraint.
     
    I am not sure that my descreption is clear enough. I think it is a problem to deal with the clearance between Shape and PTH/NPTH.
    BTW, I use SPB15.5.1.


    Originally posted in cdnusers.org by leonlee
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  • Thu, Jan 18 2007 8:14 AM

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    RE: How does the Shape's Clearance work for PTH and Nn-PTH? Reply

    You can do a couple different things to correct this issue.

    Update your padstacks anti-pads so you get the clearance from edge of hole to edge of copper on both the PTH and NPTH holes that you are looking for and set the Shape Parameters for Thru Pin to Thermal/Anti pad.
    This could have mixed results if you Net Spacing clearance is greater that the anti-pad provides which will lead to many DRCs.

    It appears that if you set your Shape Parameters for Thru Pin to DRC that your PTH has the correct clearance but the NPTH
    does not. One easy to meet your NPTH requirement is to add the Dyn_Clearance_Oversize Pin Property to the NPTH with a value that meets the spacing requirements.

    I believe the overall fix would be to have the ability to define different Spacing Rule for PTH and NPTH which is not available in the current release of software but I have heard rumors that it is a possible in a future release.

    Hope this helps,
    Mike Catrambone
    UTStarcom, Inc.


    Originally posted in cdnusers.org by mcatramb91
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  • Thu, Jan 18 2007 5:56 PM

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    RE: How does the Shape's Clearance work for PTH and Nn-PTH? Reply

    Thanks, Mike, I understand your description and solution
    Now my solution is familiar with you said.
    Add a property: Dyn_Clearance_Type=ANTI_THERMAL for all NPTH pads.
    Then set the shape parameters with Thru pin=DRC

    But all of these settings are controlled manually. And we should confirm that all the NPTH pads had been selected. 
    I hope all these actions could be easy in the future release.


    Originally posted in cdnusers.org by leonlee
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Started by archive at 18 Jan 2007 12:31 AM. Topic has 2 replies.