The body to lead correlation probably depends on what oven type you have.
We have generally seen a 5 - 15 deg. C reduction in temp when checking
inside body temp. on SOIC's and PLCC/small QFP.  We do believe (have limited
info) that the body temp. on much larger IC (QFP 160 and larger) runs hotter
than the lead temp.

                        Mark Spitnale
                        Hughes Defense Communications


At 11:20 AM 5/28/97 -0500, you wrote:

>>
>>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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>>
>----------------------------------
>Jeffery L. Hempton        phone: (219) 429-7335   Fax: (219) 429-4688
>Boardshop Manufacturing Engineer			Mail Stop: 25-31
>Hughes Defense Communications                           
>1010 Production Road, Fort Wayne, IN 46808-4106
>Email: [log in to unmask]
>
>"The man who rolls up his sleeves seldom loses his shirt."--Thomas Cowan
>
>
>
----------------------------------
Mark W. Spitnale                Phone: (219) 429-5992   Fax: (219) 429-
Hughes Defense Communications                           Mail Stop: 25-31
1010 Production Road, Fort Wayne, IN 46808-4106
Email: [log in to unmask]

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