Groove man,
          
          I would first ask: Does the customer want controlled 
          impedences on the board?  (I'm assuming they do...)
          
          Doug


______________________________ Reply Separator _________________________________
Subject: FAB: RFI/EMI Vias
Author:  [log in to unmask] at internet-mail
Date:    5/23/96 5:46 PM


          
        I have a customer who has asked me if I know about shielding vias.
     I don't know much about these. All I know is that the size of the PTH 
     and the distance apart are based, somehow, on what frequency the 
     logic (PCB) is operating at. (Yessss?)
          
        Now I don't have IEEE text books anywhere near this facility. 
     I'm a simple fabricator. Can someone who's savvy with RF <or even 
     Microwave> design give me some pointers to what kind of formulas are 
     used to determine this shield via barrier technique.
          
          
     Thanks in advance for any and all replies.
          
     Groovy