A buried resistor is an extremely thin coating of nickel 
     phosphorous deposited onto copper foil. The copper foil is 
     laminated onto B-staged laminate to form a copper clad core.
     The core is processed (etched) to define circuitry/plane images.
     (through copper and NI/P) The same layer is then re-imaged to expose
     only resistor areas. They are then selectively etched of only surface
     copper to expose Ni/P below. The Ni/P values work on the same 
     principal to ohms per square. The square size depends on the desired
     watts. Once completed, the whole multilayer composite is laminated
     together to form a MLB PCB.

                Hadco Printed Circuits
                Tech Center Two / Watsonville                


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                Dave Hoover              
                Senior Process Engineer  
                [log in to unmask]
   

______________________________ Reply Separator _________________________________
Subject: What is a buried resistor ?
Author:  [log in to unmask] at SMTPLINK-HADCO
Date:    8/15/95 4:13 PM


I am unfamiliar with this term, can someone explain ?
Mitra Geeban
PCB Designer