Atul,
    I would guess that the flux is causing a non conductive oxide to develop 
on your socket contact surfaces.  Multiple insertions are scuffing off the 
oxide layer allowing the Pentium pins to make contact, at least for now. 
 Check with your socket manufacturer to verify the quality of the contact 
plating and compatibility with your flux process.
     Norm Dill
 ----------
From: TechNet-request
To: TechNet
Subject: Flux contamination in Pentium Socket
Date: Tuesday, May 07, 1996 1:21AM

Date : 7/5/96 9:06
Msg From: ATUL RASTOGI
We are a contract manufacturer , doing mfg for a large PC
company.Recently we have been facing a problem of flux residue coming
on the contact area of ZIF socket used for Pentium.Due to this
residue when Pentium is inserted in the socket and the mother board
is powered on , it doesn't work.This happens due to the insulative
nature of the flux residue.After multiple insertions of the Pentium
it starts working.

Our process is a no clean process and our mother boards are Entek CU
106 coated.We are using spray as well as wave fluxer on our wave
soldering machines.

Does somebody has an answer or suggestions to this problem?

Thanks
Atul Rastogi
Atul Rastogi