Teflon requires as many different Feeds and Speeds as there are 
     types of teflon. Each type has different composites/fillers/layers
     that are utilized to achieve their electrical performance 
     requirements. Some can easily use the same feeds and speeds. The trick
     that I've had success with is to sandwich the materials with something 
     relatively hard. Keep the feeds and speeds low. (Almost
     like milling) Utilize a mild glass etch (frost) in your desmear 
     process and this should knock off your fibers. (Yes...desmear for 
     doublesided)
     
     Groovy


______________________________ Reply Separator _________________________________
Subject: PTFE drilling
Author:  [log in to unmask] at SMTPLINK-HADCO
Date:    10/5/95 6:58 PM


An IPC member in Sweden has asked:
     
I am seeking a good source of information on how to properly drill woven 
glass reinforced teflon material, more specificly Arlon 527.
     
Our basic problem is a formation of tiny teflon threads, firmly anchored 
in the holewall and protruding several up to 1/10 of a mm into the hole.  
During the subsequent plating steps, these tiny and hard to detect fibers 
are plated with copper causing formation of copper nodules and holesize 
below minimum.
     
     
Can anyone provide advice?
     
Thanks
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David W. Bergman, Technical Director
IPC
2215 Sanders Road
Northbrook, IL  60062-6135
708-509-9700 x340 Phone
708-509-9798 Fax
email  [log in to unmask]
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