from the United States Patent and Trademark Office, Patent
Trial and Appeal Board in No. IPR2015-00150.
Wade Vander Tuig, Senniger Powers LLP, St. Louis, MO, argued
for appellant. Also represented by Robert M. Evans, Jr., John
Maxwell James Petersen, Lewis Brisbois Bisgaard & Smith,
LLP, Chicago, IL, argued for appellee. Also represented by
THOMAS A. DOUGHERTY, Denver, CO.
WALLACH, Taranto, and Stoll, Circuit Judges.
TARANTO, Circuit Judge.
S.A. owns U.S. Patent No. 8, 557, 056, which describes and
claims methods for making steels with certain desired thermal
conductivities. In October 2014, Bbhler-Edelstahl GmbH &
Co. KG (Bohler) petitioned the Patent Trial and Appeal Board
for an inter partes review of claims 1-4 of the '056
patent. The Board instituted a review based on Bohler's
construction of the claims at issue. In its final written
decision, however, the Board rejected Bohler's
construction and adopted Rovalma's construction instead.
Bohler had not submitted arguments or evidence for
unpatentability based on Rovalma's construction.
Nevertheless, the Board determined that Rovalma's own
submissions demonstrated that the claims, construed as
Rovalma urged, would have been obvious to a relevant skilled
artisan over the same prior art that Bohler invoked.
appeals. It argues both that substantial evidence does not
support the Board's determination and that the Board
committed prejudicial procedural errors in relying on
Rovalma's own submissions when determining that the
claims would have been obvious under Rovalma's
construction. We conclude that the Board did not set forth
its reasoning in sufficient detail for us to determine what
inferences it drew from Rovalma's submissions. We
therefore cannot determine whether the Board's decision
was substantively supported and procedurally proper. We
vacate the Board's decision and remand for further
'056 patent addresses hot-work steels. It is undisputed
that hot-work steels are used at high temperatures and that
the ability to conduct and thereby remove heat-thermal
conductivity-is important for such steels. According to the
patent, hot-work steels disclosed in the prior art had
thermal conductivities of approximately 16- 37 W/mK (Watts
per meter-Kelvin), which were inade- quate for certain
applications. '056 patent, col. 1, lines 50-52; col. 4,
lines 11-14. The patent claims processes for
"setting" the thermal conductivity of a hot-work
steel at room temperature to more than 42 W/mK (higher in the
dependent claims). Id., col. 21, line 59 through
col. 22, line 64. The '056 patent discloses an allegedly
inventive process that, to achieve such higher thermal
conductivities, focuses on carbides (metal-carbon compounds)
in the steel's matrix, or lattice, structure.
Id., col. 4, lines 35-63.
summary of the invention states that "an internal
structure of the steel is metallurgically created in a
defined manner such that the carbidic constituents thereof
have a defined electron and phonon density and/or the crystal
structure thereof has a mean free length of the path for the
phonon and electron flow that is determined by specifically
created lattice defects." Id., col. 4, lines
37-43. Alternatively, the internal structure may have
"in its carbidic constituents an increased electron and
phonon density and/or which has as a result of a low defect
content in the crystal structure of the carbides and of the
metallic matrix surrounding them an increased mean free
length of the path for the phonon and electron flow."
Id., col. 4, lines 54-58.
The patent includes four claims. Claim 1 recites:
1. A process for setting a thermal conductivity of a hot-work
steel, which comprises the steps of:
providing a hot-work steel, including carbidic constituents
and, by weight, 2-10% Mo寥 [molybdenum tungsten
metallurgically creating an internal structure of the steel
in a defined manner such that carbidic constituents thereof
have at least one of a defined electron and phonon density
and a crystal structure thereof having a mean free length of
a path for a phonon and electron flow being determined by
specifically created lattice defects;
a) a surface fraction and thermal conductivity of the
carbidic constituents and a particular surface fraction and
thermal conductivity of a matrix material containing the
carbidic constituents; or
b) a volume fraction and thermal conductivity of the carbidic
constituents and thermal conductivity of the matrix material
containing the carbidic constituents; and
setting the thermal conductivity of the steel at room
temperature to ...