We just began a project requiring insertion of Harting brand 
     connectors into boards with OPC over bare copper. 
     pitfall 1: board thru-holes (drill) were too small and some pins did 
     not seat. Insertion force was 2X the expected level
     pitfall 2: boards with enlarged thru-holes, but barrel copper plating 
     thickness was less than specified by Harting. Some barrels were torn 
     by the inserted pin, and nodules of copper were stuck to the pin tip.
     pitfall 3: to reduce the possibility of barrel damage, we are 
     lubricating pins before insertion with socket lubricant. Lubricant 
     reduced the pullout force very slightly, but not a problem. Very low 
     occurrence of barrel damage.
     In the future, we plan to use thicker barrel plating. Hopefully this 
     will prevent the barrel tearing without greatly increasing the 
     press-in force.
     Harting said they had little experience with non-tinned boards. 
     They've been helpful.
     
     Allen Ahlert
     Hitachi Computer Products
     [log in to unmask]


______________________________ Reply Separator _________________________________
Subject: Press fit technology on ENTEK boards...
Author:  [log in to unmask] at halsic_ccsmtp
Date:    6/7/95 3:44 PM


Hi 
all,
     
I just joined the forum as a result of "surfing the web" into the 
IPC home page and reading all of your interesting mail.  I was 
particulary intrigued by the discussion on ENTEK materials as we 
are in process here at Teradyne of implementing ENTEK on all
our SMT/Mixed technology boards.  We are also faced with having to 
use ENTEK on some boards employing press fit connectors.
     
Question: HAVE ANY OF YOU WHO ARE USING BARE COPPER/ENTEK USED
 PRESS FIT ALSO?  IF SO, I WOULD BE GRATEFUL FOR ANY ADVICE 
 AND/OR PITFALLS.
     
     
Thanks,
     
Dean Barham
Mgr. Mfg. Eng.
DFM Technology
Teradyne, Inc.
Boston