Appeal No. 2003-1246
Application 08/393,617
0-25% of a metal oxide, which can be zinc oxide, lead oxide, or a
mixture of the two, with zinc oxide being preferred (col. 3, ll.
1-10). Even more desirable compositions are ternary systems
containing 50-75% of V205, 15-40% of P2O5, and 5-20% of metal
oxide, which is zinc oxide, lead oxide, or a mixture of the two
(col. 3, ll. 11-19). Weaver further explains that the glass
compositions may additionally contain other metal oxides, such as
antimony oxide and boron oxide (the two main components in
Snell's glass compositions), in an amount up to about 15% by
weight (col. 3, ll. 31-37). Antimony oxide adjusts the
electrical resistivity of the glass and boron oxide improves the
flow properties of the fused glass (col. 3, ll. 38-43).
The examiner contends it would have been obvious in view of
Weaver to replace the PbO in Snell's solder glass with ZnO:
Weaver shows that ZnO is equivalent to PbO for use in
solder glass (see abstract line[s] 7 and 8; column 2
lines 31 and 32; column 2 lines 57-58 and column 3
line[s] 9 and 10). Therefore, because these two
components were recognized equivalent[s] at the time
the invention was made, on[e] of ordinary skill in the
art would have found it obvious to substitute ZnO for
PbO in the solder glass (22) of Snell et al. For
example, one reason for substituting ZnO for PbO might
be the known safety hazards associated with lead use.
Final Office action (Paper No. 20), at 2-3; Answer at 2-3.
In response to Appellants' argument that "Weaver teaches the
equivalence of PbO and ZnO in a vanadium-phosphorous solder glass
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