Appeal No. 2001-2200
Application No. 09/286,328
way to decrease the dynamic stress migration was to avoid the consequential increase
in grain size associated with the heat treatment.
The problem with foregoing heat treatment at 400° C, however, was that the
alloy between Al and the transition metal was not formed between the layers. There
was no structure to function as a "stopper" for inhibiting cracks occurring in the film (i.e.,
the growth of voids). '917 patent at col. 5, ll. 5-15.
Appellants' solution was to alternately laminate "a film of aluminum containing at
least copper added thereto or an alloy of such aluminum and a copper film." Id. at ll.
27-32. For reducing stress migration of the aluminum, the sum of the internal stresses
of the Al alloy and the copper (Cu) film was to be zero or compressive. Id. at ll. 34-41.
Appellants broadly described embodying the invention using two or three-layered
laminate structures, requiring temperatures no greater than 200° C in forming the
laminates. Id. at col. 5, l. 42 - col. 6, l. 39.
Appellants disclosed, in more detail, two and three-layered laminates consistent
with their summary description of the invention. Appellants' description of the preferred
embodiments underscored the conviction that stress migration was reduced by mutual
bonding between the copper in the Al-Cu films and the Cu film in contact within the
structure. See, e.g., id. at col. 8, ll. 1-54.
-4-
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007