2 Replies Latest reply on Aug 5, 2013 12:11 PM by Vern_Wnek

    general  clearance rule for all non plated holes of design ?

    mbruehl

      Hi all,

       

      Is there a general clearance rule for all non plated holes in a design ?

      Some pcb manufacture want to have at lease 3-4 mm non-copper area around non plated holes in all layers,

      and changed from manufacture to manufature, so a clearance in library is not really helpful.

       

      Thank in advance,

      Michael

        • 1. Re: general  clearance rule for all non plated holes of design ?
          Pete

          If you are trying to set rules for wach manufacturer, clearances in the design will not help, either.  What if Supply Chain changes manufacturers?

           

          If you do not have an approved list of fabricators, you need to set your clearance based on the least capable manufacturer.  And don't forget to add location and feature tolerances.  You should do that in the library, saves recalculation and errors.

          • 2. Re: general  clearance rule for all non plated holes of design ?
            Vern_Wnek

            I agree with Pete, and from my experience in the board industry over the years I have found that most houses ask for at least a minimum of 10mils per side (20mils oversize) for clearance on all non-plated holes. This is quite large for the dense designs most see today. But fab vendors have found that this is a good number for film tent adhesion prior to etch processes. In many cases you may not realize that the fab house edits your data to allow for this, if you do not provide enough clearance.

             

            I build 20 mil clearances into all Non-plated holes within my library components.

             

            Good Luck,

            Vern Wnek