---------- Forwarded message ----------
Date: Thu, 29 Feb 96 10:16:00 CST
From: Thorson, Kevin J @EAG <[log in to unmask]>
To: 'IPC Technical Forum' <[log in to unmask]>
Subject: Surface Mount Considerations


I am working with a design that requires CTE management for solderjoint 
fatigue of a leadless ceramic component, and I am considering random fiber 
aramid pwb construction.  The problem I have is that the solder side copper 
heat sink modulus is almost 10X that of the pwb and the results of the 
composite heat sink assembly is of little benefit of CTE the component sees.

Can anyone recommend a heat sink/pwb adhesive that is forgiving enough to 
allow the expansion differences while still having good properties of 
shear/peel strength and thermally conductive?

Thank You in Advance,
Kevin Thorson