Richard,
          
          I understand that well.  But, I'm more concerned about 
          dielectric material and frequencies up to about 30 GHz.  FR4 
          is crap for our purposes beyond 800 MHz.  We've seen a 1.5 dB 
          difference in signal from one side of the board to the other 
          in addition to variances from board to board.
          
          I can't cost justify the ADDITION of "new materials" for 
          buried capacitance techniques against the REMOVAL of 
          decoupling capacitors achieving the same effect.
          
          Your response is exactly in line with the way I am thinking 
          at this moment -
          
            "keep the components, but, change the pcb stacking"
          
            versus
          
            "throw out the components, but, change to new material and 
            pcb stacking"?
          
          The stacking may have to change in either case, so it's a 
          wash.  Thus, it's a "components" versus "new material" issue 
          now.
          
          This is actually the third part of the my other questions 
          concerning: 1. Humidity testing of printed circuit board 
          materials that was so vague, and, 2. Modeling frequency 
          response for a trace on a board that's getting it's share of 
          responses.
          
          I'm looking for as much information as I can get.
          
          And, again, I thank everyone for their input.
          
          Doug McKean, [log in to unmask]
          
          ____________________ Reply Separator _______________________ 
          Subject: Re: DES:  New Material?
          Author:  "Richard Davidowsky" 
          <[log in to unmask]> at internet-mail 
          Date:    5/10/96 6:14 PM
          
          Buried capacitance is achieved by the power and ground planes 
          being so close together they form a large plate capacitance. 
          The dielectric spacing between planes is very small, less 
          than 3 mils. 
          
          From:          [log in to unmask]
          Date:          Fri, 10 May 96 14:19:25 CST
          To:            [log in to unmask], [log in to unmask] 
          Subject:       DES:  New Material?
          
          
          Does anyone have any experience with "Buried Capacitance" 
          materials for p.c. boards?
          
          Since I do alot of EMI/EMC control on products at the p.c. 
          board construction level.  I'd like any input about this 
          stuff from the FIELD.
          
                     The Zycon Corp. calls it ZBC-2000.
                     I am NOT advertising this product.           
                     Assume my frequency ranges out to 30 GHz.         
          
                     Doug McKean,  [log in to unmask]