Appeal No. 1998-0773 Page 6
Application No. 08/578,106
compositions described by Wu could have been successfully used in the resistance composition of
Hankey or that one of ordinary skill in the art would have reasonably expected that inclusion of the
mixed alkaline earth metal oxides of Wu would have resulted in stable copper compatible resistance
compositions in the environment of Hankey.
The Examiner points out that Wu describes alkaline earth metal oxides as generally having
resistivities of about 10 to 20 times those of copper. The Examiner concludes that it would have been
obvious for one skilled in the art at the time the invention was made to have substituted Wu’s resistive
material for Hankey’s resistive material because one skilled in the art would have wanted to obtain a
more resistive paste as evidenced by Wu (Answer, page 4). There is no evidence that the metal oxides
of Wu are more resistive than the metal oxides of Hankey. While we acknowledge that Wu teaches
that the alkaline earth metal oxides generally have resistivities of about 10 to 20 times those of copper,
this fact alone does not provide a reason, suggestion, or motivation to use the mixed alkaline earth metal
oxide in place of the other alkaline earth metal oxides which Hankey describes as being copper
compatible, stable, reproducible and less subject to processing sensitivity in thick film resistor paste
systems. At best, it might have been reasonable for one of ordinary skill in the art to experiment with
the mixed alkaline earth metal oxide. However, neither Hankey nor Wu provide any reason to believe
that the stability, reproducibility and sensitivity would be the same or better with the mixed alkaline earth
metal oxide.
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