Hi Vic
     
     One problem you will encounter is "boiling" the flux out of the solder 
     paste and launching solderballs everywhere. A controlled preheat ramp 
     prevents this from happening.
     
     
     Dave Hillman
     Rockwell Collins
     [log in to unmask]
     


______________________________ Reply Separator _________________________________
Subject: Changing of reflow profile.
Author:  [log in to unmask] at ccmgw1
Date:    7/1/96 10:20 AM


     
Hi, 
I am a student doing research at the temperature issue during the IR 
reflow process.  As I know that there is a well-defined temperature 
profile for the PCB when passing through the oven.   I just wonder if it 
is possible to forget all the preheat, ramp up periods and go straight 
into the spike zone where solder paste will melt at that temperature?
     
What are the potential problems I have to face in this context, excluding 
the thermal mass issue?
     
Any input is appreciated.  Thanks in advance.
     
Vic.
[log in to unmask]