We tend to use simple solutions here.  Try shearing small rectangles of
copper clad fiberglass (0.062 double-sided PWB stock) with a slight overhang
(+ 0.1"). The fiberglass insulates and the copper acts as a heatsink.  Our
oven is not a latest "high convection design" so please check out its
sheilding capability for your process.  I'm sure some clever type out their
is trying to figure out how to place these with his Fuji.   If more shielding
on the sides is needed, use aluminum or stainless sheet stock bent into
covers that free stand on the PWB.  Two or four sides may be covered.  If
there is no room for the footprint, consider combining the two ideas.  Use
the clad fiberglass to support a shield on top of the part. 
 Good luck and report back.

Steve Mikell, Process Engineer @ SCI Systems, Plant 13, Huntsville, AL
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