Appeal No. 95-2500
Application No. 07/984,147
amounts of the two materials making up the
composite. The references do not, however, discuss
edge effects. Since the low coefficient of thermal
expansion semiconductor material and ceramic are
both mounted to a surface in the references, the
references would not be concerned with edge effects.
[Emphasis added.]
There is nothing in any of the references of
record, or in Appellants' description of the prior
art, to teach or suggest that at the edges of a
composite material, where multiple metals are in
contact with a molding resin, the composite heat
spreader will not fracture the molding resin of a
molded plastic package.
We note that the examiner has chosen not to respond to this
cogent argument of appellants.
Consequently, in the absence of any teaching or
suggestion in the prior art that the composite heat spreaders
of Gernitis, Hascoe and Alvarez could be successfully employed
while embedded in the plastic housing of an electronic
package, we must agree with appellants that the examiner's
rejection is based upon impermissible hindsight.
Kato, Butt, Yerman and Hynes, applied by the examiner to
establish the obviousness of using composite leadframes, as
recited in claims 75 and 76, do not remedy the deficiency of
the combination of references discussed above.
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