3 Replies Latest reply on Aug 17, 2010 4:00 AM by Mentor_Per_Viklund

    Stacked or staggered microvias

    tenny_thomas

      Hi,

       

      Is it possible to create the stacked or staggered microvias in layers 1-2 and 2-3, when the layer stack up is foil-prepreg-core-prepreg-core-prepreg-foil (6 layers)?

       

      Thanks in advance.

        • 1. Re: Stacked or staggered microvias
          Mentor_Per_Viklund

          That is a question you need to direct to your board manufacturer.

           

          There are laser drillable pre-preg materials out there so the theoretical answer is: yes you can.

           

          The question becomes: Is that cost effective, reliable etc...

           

          Also, what is the reason for that very specific stack up? -The same "sandwich"-end result can be achieved through other manufacturing stacks also. -Some that better lend themselves to staggered and stacked micro vias.

          Best advice: Work out an optimal stack up with the board shop. They know what works. -Bring  your SI engineers into the discussion if needed

          .

           

          /Per Viklund

          • 2. Re: Stacked or staggered microvias
            tenny_thomas

            Thanks for the reply.

             

            I heard that one can create the stacked/staggered microvias in the layers 1-2 & 2-3 and skip microvia in the layer 1-3 of 6 layer stack up, when the prepreg is between layers 1 & 2 and the other prepreg is between the layers 2 & 3. I want to know whether there is a possibility to create the same, when the prepreg (laser) is between layers 1-2 and the core is between layers 2-3, even when the PCB manufacturing company can make it.

             

            Thanks in advance.

            • 3. Re: Stacked or staggered microvias
              Mentor_Per_Viklund

              Are you asking if you can set this up in the layout tool so that interactive and automatic routing will use such vias with the stack up you mention?

              You are not telling which layout tool you are using but if its Expedition the answer is yes.

              Set up the layer stackup in CES and the via spans in "Setup=>Parameters"

               

              /Per

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