Steve,
     
        You don't state what type of reflow process you are using.  If your 
     reflow oven is an IR unit, your body temperature could be exceeding 
     the stated maximum.  The organics, e.g. the IC body, will reach a 
     higher temperature than the leads in an IR unit.  Have you tried 
     profiling the body temperature?
     
     Gary Camac
     Dickey-john Corp.
     [log in to unmask]
       


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Subject: ASSY:  Profiling parts.
Author:  INTERNET:[log in to unmask] at CSERVE
Date:    5/28/97 11:15 AM


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Subject: ASSY:  Profiling parts.
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We have profiled an IC, which we are now seeing failures on.  The max temp 
on the leg of the part was 217 C.  We have been told by our supplier that 
the max temp for the part is 221 C.  They are saying we are reflowing solder 
internally, which causes a short, and the failure.  
        My question is, does anyone have a good idea of what the correlation
is from external temps on the leg of a part, to the internal temps of an IC.
     
Thanks for any ideas or data to prove us right or wrong.
     
     
Steve Quinn
Heurikon Corp
Madison, Wi
     
608/831-5500
     
[log in to unmask]
     
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