Appeal No. 1998-1374
Application No. 08/466,562
adhesion strength of the copper on the ceramic substrate,
Nakatani discloses at column 4, lines 32 through 47 that:
When the copper particles and the ceramic material
are to be adhered through the heat treatment in a
nitrogen gas atmosphere, the presence of CuO or Cu O
2
plays a great role on the adhesion. This is because
the copper particles and the ceramic do not become
wet in the nitrogen gas atmosphere and the adhesion
reaction takes place between them only when CuO
exists. For this reason, the conventional copper
paste has adopted such a method that the copper
particles have their surfaces partially oxidized, or
CuO is added to the copper paste in advance, or the
like. In this case, CuO or Cu O forms a CuAl O layer2 24
on an alumina substrate thereby to enhance the
adhesion strength. Therefore, the use of CuAl O as
2 4
the additive makes it possible to provide an
adequate effect on the adhesion properties when
added in a small amount. (underlining added).
Thus, Nakatani is directed to pastes comprising copper
particles. Appellants' arguments concerning the amount of
copper aluminate added to the pastes of claims 2 through 7 and
10 are unpersuasive. As appellants acknowledge, Nakatani
describes the use of from 0.5 to 20 weight percent copper
aluminate, an amount which completely includes the amounts
claimed in claims 2 through 7 and 10. While appellants argue
that they have demonstrated unexpected or surprising results
for grain size control and shrinkage at levels of addition of
less than 0.5 weight percent, the minimum amount disclosed by
9
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