  United States Court of Appeals
      for the Federal Circuit
                ______________________

          KNOWLES ELECTRONICS LLC,
                  Appellant

                           v.

       CIRRUS LOGIC, INC., CIRRUS LOGIC
          INTERNATIONAL (UK) LTD.,
                    Appellees
             ______________________

                      2016-2010
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in Nos. 95/000,509,
95/001,251, 95/001,363.
                 ______________________

                Decided: March 1, 2018
                ______________________

    RICHARD L. RAINEY, Covington & Burling LLP, Wash-
ington, DC, argued for appellant. Also represented by
CYRIL DJOUKENG, BRIAN GERARD BIELUCH, MICHAEL S.
SAWYER.

   NATHAN R. SPEED, Wolf, Greenfield & Sacks, PC,
Boston, MA, argued for appellees. Also represented by
JUSTIN COLANNINO, RICHARD GIUNTA, MARC S. JOHANNES.
               ______________________

  Before NEWMAN, WALLACH, and CHEN, Circuit Judges.
2                   KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.



    Opinion for the court filed by Circuit Judge WALLACH.
     Dissenting opinion filed by Circuit Judge NEWMAN.
WALLACH, Circuit Judge.
    Appellant Knowles Electronics, LLC (“Knowles”) ap-
peals the inter partes reexamination decision on appeal of
the U.S. Patent and Trademark Office’s (“USPTO”) Pa-
tent Trial and Appeal Board (“PTAB”) affirming an exam-
iner’s rejection of claims 1−4 of U.S. Patent No. 6,781,231
(“the ’231 patent”) for anticipation and proposed claims
23−27 for lack of an adequate written description. 1
Cirrus Logic, Inc. v. Knowles Elecs. LLC (Cirrus I), No.
2015-004342, 2015 WL 5272691, at *2−3 (P.T.A.B. Sept.
8, 2015); see Cirrus Logic, Inc. v. Knowles Elecs. LLC
(Cirrus II), No. 2015-004342, 2016 WL 1378707, at *1−2
(P.T.A.B. Apr. 5, 2016) (denying request for rehearing).
   Knowles appeals. We have subject matter jurisdiction
pursuant to 28 U.S.C. § 1295(a)(4)(A) (2012). We affirm.
                       BACKGROUND
    The ’231 patent, entitled “Microelectromechanical
System Package with Environmental and Interference
Shield,”    discloses    microelectromechanical   system
(“MEMS”) packages comprising a substrate, a micro-
phone, and a cover accommodating the microphone. ’231
patent, Abstract. The MEMS packages shield the micro-
phone from an interference signal or an environmental
condition, id. col. 1 ll. 38−41, and purportedly improve
over the prior art’s drawbacks “associated with manufac-



     1 Claims 23−27 were proposed as additions to the
’231 patent and repeatedly amended during the inter
partes reexamination. See, e.g., J.A. 614−15, 2800−01,
3886−87.
KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.               3



turing these housings, such as lead time, cost, and tool-
ing,” id. col. 1 ll. 30−32.
     The instant appeal concerns claims 1−4 and proposed
claims 23−27 of the ’231 patent. Independent claim 1 is
illustrative of the invention and recites:
   A microelectromechanical system package com-
   prising:
       a microelectromechanical system micro-
       phone;
       a substrate comprising a surface for sup-
       porting the microelectromechanical micro-
       phone;
       a cover comprising a conductive layer hav-
       ing a center portion bounded by a periph-
       eral edge portion; and
       a housing formed by connecting the pe-
       ripheral edge portion of the cover to the
       substrate, the center portion of the cover
       spaced from the surface of the substrate to
       accommodate the microelectromechanical
       system microphone, the housing including
       an acoustic port for allowing an acoustic
       signal to reach the microelectromechanical
       system microphone wherein the housing
       provides protection from an interference
       signal.
Id. col. 5 ll. 12−25 (emphasis added). Claims 2−4 also
recite a “package.” See id. col. 5 ll. 26, 39, 53. Proposed
claims 23−27 recite a package with a “lower surface
comprising a plurality of solder pads” that is “configured
to mechanically attach and electrically connect the
[MEMS] package” to a printed circuit board “using a
solder reflow process.” J.A. 3886 (emphasis added); see
J.A. 3886−87.
4                  KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.



                       DISCUSSION
    Knowles raises three primary arguments on appeal.
First, Knowles argues that “the [PTAB]’s rejection of the
potentially most commonly accepted definition of ‘pack-
age,’ and corresponding invalidity finding, requires rever-
sal” as to claims 1–4. Appellant’s Br. 45 (capitalization
and alterations omitted); see id. at 45−63. 2 Second,
Knowles argues that “the [PTAB]’s written description
analysis requires reversal” as to the PTAB’s rejection of
proposed claims 23–27. Id. at 63 (capitalization and
alterations omitted); see id. at 63−74. Finally, Knowles
contends that “the record does not establish that the
[Appellees] are proper parties.” Id. at 75 (capitalization
omitted); see id. at 75−79. After articulating the applica-
ble standard of review and legal standards, we address
Knowles’s arguments in turn.
           I. Claim Construction in Claims 1–4
        A. Standard of Review and Legal Standard
    “We review the [PTAB]’s ultimate claim construction
in a reexamination de novo.” In re CSB-Sys. Int’l, Inc.,
832 F.3d 1335, 1340 (Fed. Cir. 2016) (citing, inter alia,
Teva Pharm. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831,
840–41 (2015)). A patent’s specification, together with its
prosecution history, 3 constitutes intrinsic evidence to


    2   Knowles also argues that the PTAB erred in find-
ing claims 1–4 anticipated by the prior art. See Appel-
lant’s Br. 61–63.      However, Knowles’s anticipation
arguments are primarily premised on its proposed con-
struction of “package,” see id., which we decline to adopt.
We have considered the remaining arguments, but do not
find them persuasive.
    3   A patent’s prosecution history “consists of the
complete record of the proceedings before the [US]PTO,”
KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.                5



which the PTAB gives priority when it construes claims.
See Microsoft Corp. v. Proxyconn, Inc., 789 F.3d 1292,
1297–98 (Fed. Cir. 2015). We review the PTAB’s assess-
ment of intrinsic evidence de novo. See id. When the
PTAB “look[s] beyond the patent’s intrinsic evidence
and . . . consult[s] extrinsic evidence,” such as expert
testimony, dictionaries, and treatises, Teva, 135 S. Ct. at
841, those underlying findings amount to factual deter-
minations that we review for “substantial evidence,”
Microsoft Corp., 789 F.3d at 1297 (citation omitted).
Substantial evidence means such “relevant evidence
[that] a reasonable mind might accept as adequate to
support a conclusion.” Consol. Edison Co. v. NLRB, 305
U.S. 197, 229 (1938) (citations omitted). “If the evidence
in record will support several reasonable but contradicto-
ry conclusions,” we “will not find the [PTAB’s] decision
unsupported by substantial evidence simply because the
[PTAB] chose one conclusion over another plausible
alternative.” In re Jolley, 308 F.3d 1317, 1320 (Fed. Cir.
2002).
    “During reexamination proceedings of unexpired pa-
tents . . . the [PTAB] uses the broadest reasonable inter-
pretation [(‘BRI’)] consistent with the specification
standard . . . .” In re CSB-Sys., 832 F.3d at 1340 (internal
quotation marks and citation omitted); cf. Cuozzo Speed
Techs., LLC v. Lee, 136 S. Ct. 2131, 2144−45 (2016) (ac-
knowledging the PTAB’s use of BRI during reexamina-
tion). “Accordingly, this court reviews the reasonableness
of the [US]PTO’s disputed claim term interpretations.” In
re Bigio, 381 F.3d 1320, 1324 (Fed. Cir. 2004) (internal



which provides “evidence of how the [US]PTO and the
inventor understood the patent.” Phillips v. AWH Corp.,
415 F.3d 1303, 1317 (Fed. Cir. 2005) (en banc) (citations
omitted).
6                   KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.



quotation marks and citation omitted). However, “[e]ven
under the [BRI], the [PTAB’s] construction cannot be
divorced from the specification and the record evi-
dence . . . and must be consistent with the one that those
skilled in the art would reach.” Microsoft Corp., 789 F.3d
at 1298 (internal quotation marks and citations omitted).
B. The PTAB Properly Construed the Term “Package” in
                    Claims 1–4
    Knowles makes several arguments for why the
PTAB’s construction of “package” in the preamble of claim
1 of the ’231 patent is incorrect. 4 The PTAB found that,
under the BRI, a “package” “may refer to chip assemblies
that possess any type of second-level connection mecha-
nism.” Cirrus I, 2015 WL 5272691, at *11; see Cirrus II,
2016 WL 1378707, at *4 (“[T]he Panel explained why the
[BRI] of ‘package’ included, but was not limited to, pack-
ages produced from [Knowles’s] two [proposed] mounting
methods.” (citation omitted)). 5 On appeal, Knowles con-


    4   The PTAB correctly found the preamble term
“package” limiting. See Cirrus I, 2015 WL 5272691, at
*10. A preamble is limiting when it “recit[es] additional
structure or steps underscored as important by the speci-
fication.” Catalina Mktg. Int’l, Inc. v. Coolsavings.com,
Inc., 289 F.3d 801, 808 (Fed. Cir. 2002) (citations omit-
ted). The parties do not contest this finding.
    5   Knowles notes that the PTAB used conflicting
language on whether it construed the term “package” to
include assemblies without a second-level connection. See
Appellant’s Br. 45−46. Compare Cirrus I, 2015 WL
5272691, at *11 (“[T]his industry definition provides
evidence that a package need not even necessarily include
any second-level connection at all.”); id. (similar), with id.
at *12 n.7 (“[T]he extrinsic evidence additionally seems to
indicate that a chip package need not even possess any
KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.              7



tends that the term “package” should be construed to
mean an assembly that “requires a second-level connec-
tion with a mounting mechanism.” Appellant’s Br. 47.
Thus, Knowles disagrees with the PTAB’s construction,
which does not limit the “connection” to one that uses a
“mounting mechanism.” 6
    Claims 1−4 do not specify the type of connection re-
quired to form the MEMS package. See ’231 patent col. 5



second-level connection at all. However, we need not
reach this finding to resolve the present appeal.”). Be-
cause the PTAB’s final and most definitive statement is
that it “need not reach” the question of second-level
connectivity, id. at *12 n.7, we understand the PTAB not
to have decided whether the definition of “package” in-
cludes fewer than two levels of connectivity.
    6   Knowles argued before the PTAB that the term
“package” required a second-level connection “by either
through-hole mounting or surface mounting.” Cirrus I,
2015 WL 5272691, at *10. Knowles appears to make the
same arguments on appeal, though it at times uses the
general term “mountable.” See, e.g., Appellant’s Br. 50
(stating the submitted extrinsic evidence shows that
persons having ordinary skill in the art (“PHOSITA”)
“recognized two categories of mounting types for microe-
lectronics packages to form second-level connections,
through-hole and surface mount”), 53, 59, 63 (using the
term “mountable”); Reply Br. 10 (discussing evidence
showing all packages are classified as “through hole” or
“surface mount” (citations omitted)). We consider only the
construction Knowles presented to the PTAB because
“[a]bsent exceptional circumstances, we generally do not
consider arguments that the applicant failed to present to
the [PTAB].” In re Baxter Int’l, Inc., 678 F.3d 1357, 1362
(Fed. Cir. 2012) (internal citations omitted).
8                   KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.



ll. 12−67. The ’231 patent’s specification similarly does
not limit the type of connection to one that is mountable
or any specific form of mount. See, e.g., id. col. 3 ll. 4−7
(“The embodiment disclosed herein . . . would typically be
mounted . . . .” (emphasis added)), col. 3 ll. 19−20 (describ-
ing the package to include “surface mountable compo-
nents” without detailing the means of required connection
with an external mechanism), col. 4 ll. 3−4 (describing
general “electrical connection” of the substrate). Moreo-
ver, the parties do not identify any disclosures in the
prosecution history that would aid in the construction of
the term.
    Because intrinsic evidence is not definitive, we turn to
extrinsic evidence. See Phillips, 415 F.3d at 1319 (allow-
ing courts to look to extrinsic evidence after reviewing
intrinsic evidence to better understand the field of the
invention and the meaning of a term to a PHOSITA).
Knowles asks the court to look only at certain dictionary
and treatise references describing common categories for
mounting in MEMS to form second-level connections. See
Appellant’s Br. 50−52. However, as the PTAB correctly
noted, many references suggested by Knowles use qualify-
ing language, thereby implying second-level connections
in circuit boards may not be properly limited to the two
types of mounts proffered by Knowles. See Cirrus I, 2015
WL 5272691, at *11 (quoting Fundamentals of Microsys-
tems Packaging 67 (Rao R. Tummala ed., 2001)
(J.A. 2833) (“In general, . . . packages can be classified
into two categories: 1) through-hole, and 2) surface
mount.”) (emphasis added)); id. (quoting Microelectronics
Packaging Handbook 42 (Rao R. Tummala et al. eds.,
1989) (J.A. 2847) (“There are two basic types of connec-
tions . . . .”) (emphasis added)); id. (quoting Handbook of
Electronic Package Design 4 (Michael Pecht ed., 1991)
(J.A. 2842) (“The external connections of a chip carrier
serve to classify the component into one of the two major
technological categories . . . .”) (emphasis added)). Moreo-
KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.                 9



ver, Knowles provided additional extrinsic evidence that
supports the PTAB’s determination that a package need
not be confined to certain types of second-level connection
mounts. See Cirrus I, 2015 WL 5272691, at *11−12
(reviewing Electronic Industries Alliance JEDEC Stand-
ard defining package as “[a]n enclosure . . . that allows
electrical connection and provides mechanical and envi-
ronmental protection” (J.A. 637−38), and a technical
dictionary definition defining package as, inter alia, “an
enclosure . . . used to contain any level of electronic sys-
tem or subsystem” (J.A. 642−43)).
    Knowles does not contest that the references cited by
the PTAB allow for means of connectivity beyond surface
and through-hole mounts. Instead, Knowles argues that
the PTAB impermissibly “simply select[ed] the broadest
definition” cited by the parties to arrive at its claim
construction. Appellant’s Br. 55 (quoting PPC Broad-
band, Inc. v. Corning Optical Commc’ns RF, LLC, 815
F.3d 747, 752 (Fed. Cir. 2016)). That is incorrect. The
PTAB reviewed all extrinsic evidence, including evidence
proffered by Knowles, and found no evidence that the
definition was limited to surface or through-hole mount-
ing. Unlike PPC Broadband, where the PTAB failed to
consider evidence “in light of the specification” and
“claims themselves,” 815 F.3d at 752, Knowles admitted
that the claims and specification did not offer a definition
for package that would inform a PHOSITA as to its fa-
vored interpretation, see J.A. 4152 (“[The ’231 pa-
tent] . . . does not offer a concise dictionary definition of
the term.”), 6907 (similar). Therefore, the PTAB properly
considered extrinsic evidence, and we see no error in the
PTAB’s claim construction based on this extrinsic evi-
dence.
    Knowles additionally argues that “[t]he [PTAB]
should have read MEMS Technology and concluded that a
‘package’ requires a ‘self-contained unit[’] . . . and that
this unit must be ‘mountable.’” Appellant’s Br. 53 (citing
10                  KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.



MEMS Tech. Berhad v. Int’l Trade Comm’n, 447 F. App’x
142 (Fed. Cir. 2011)). This is so, Knowles avers, because
the PTAB has an obligation to “evaluate a previous judi-
cial interpretation of disputed claims ‘and to determine
whether it is consistent with the [BRI] of the term.’” Id.
at 59 (alteration omitted) (quoting Power Integrations,
Inc. v. Lee, 797 F.3d 1318, 1327 (Fed. Cir. 2015)). We
disagree with the premise of Knowles’s argument suggest-
ing that the PTAB’s claim construction conflicts with
MEMS Technology. In MEMS Technology, we upheld the
International Trade Commission’s construction of the
term “package” in the ’231 patent’s preamble to mean “a
self-contained unit that has two levels of connection, to
the device and to a circuit (or other system).” 447 F.
App’x at 159; see id. (affirming the ITC’s rejection of an
anticipation claim because the disputed prior art “does
not disclose first and second levels of electrical connec-
tion”). Thus, the claim construction in MEMS Technology
did not require that a package be mounted via surface or
through-hole mounts, such that even if we were to look to
MEMS Technology, we would find no inconsistency with
the PTAB’s construction of the claim term “package” here.
    Further, Knowles argues that this court’s construction
in MEMS Technology differed from the PTAB’s below
because in MEMS Technology we stated “[t]he require-
ment that the components listed in the claim body come
together to form a mountable package is . . . an important
characteristic of the claimed invention.” Id. at 154 (inter-
nal quotation marks and citation omitted); see Appellant’s
Br. 59−61. We made this statement in the context of
finding that the preamble was a claim limitation, see
Catalina Mktg., 289 F.3d at 808 (stating preambles may
be limiting if they “recit[e] additional structure or steps
underscored as important by the specification”), not in the
context of construing the term’s disputed meaning. Later
in the opinion, we applied the ITC’s construction that a
package “is a self-contained unit that has two levels of
KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.                11



connection, to the device and to a circuit (or other sys-
tem).” MEMS Tech., 447 F. App’x at 159. “We will not
find legal error based upon an isolated statement stripped
from its context.” VirnetX Inc. v. Apple Inc., 665 F. App’x
880, 886 (Fed. Cir. 2016). We fail to see how the defini-
tion of package adopted by the PTAB below does not
accord with the definition adopted in MEMS Technology.
Neither definition limited the two levels of connection to
surface or through-hole mounting. In sum, we find that
the PTAB properly construed the claim term “package.”
    II. Written Description in Proposed Claims 23–27
        A. Standard of Review and Legal Standard
    “The [PTAB]’s determination that a patent claim is
unpatentable for insufficient written description support
is a question of fact that we review for substantial evi-
dence.” Blue Calypso, LLC v. Groupon, Inc., 815 F.3d
1331, 1344 (Fed. Cir. 2016). According to 35 U.S.C. § 112
¶ 1 (2006), 7 “[t]he specification shall contain a written
description of the invention, and of the manner and
process of making and using it, in such full, clear, concise,
and exact terms as to enable any [PHOSITA] to which it
pertains . . . to make and use the same.” The written
description “must clearly allow [a PHOSITA] to recognize
that the inventor invented what is claimed.” Ariad
Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed.



    7   Congress amended § 112 when it enacted the
Leahy-Smith America Invents Act (“AIA”), Pub. L. No.
112-29, § 4(c), 125 Stat. 284, 296−97 (2011), and AIA
§ 4(e) made those changes applicable to “any patent
application that is filed on or after” September 16, 2012,
see 125 Stat. 296―97. Because the application that led to
the ’231 patent was filed before September 16, 2012, the
pre-AIA § 112 applies.
12                  KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.



Cir. 2010) (en banc) (internal quotation marks and brack-
ets omitted). “[A] description which renders obvious a
claimed invention is not sufficient to satisfy the written
description requirement of that invention.” Regents of the
Univ. of Cal. v. Eli Lilly & Co., 119 F.3d 1559, 1567 (Fed.
Cir. 1997). “[T]he hallmark of written description is
disclosure. . . . [T]he test requires an objective inquiry
into the four corners of the specification from the perspec-
tive of a [PHOSITA].” Ariad, 598 F.3d at 1351.
  B. Substantial Evidence Supports the PTAB’s Lack of
 Adequate Written Description Determination as to Pro-
                  posed Claims 23–27
     Proposed claims 23−27 of the ’231 patent recite a
MEMS package wherein the solder pads are “configured
to mechanically attach and electrically connect the pack-
age to a surface of an external printed circuit board using
a solder reflow process.” J.A. 3886; see J.A. 3886−87. The
PTAB determined that proposed claims 23–27 failed to
meet the written description requirement, because “the
present [s]pecification merely discloses a genus―solder
pads that are capable of being connected to a board. But
the [s]pecification fails completely to disclose the newly
claimed species of such pads―pads that are connectable to
a board specifically by using a reflow process.” Cirrus I,
2015 WL 5272691, at *8. Knowles argues that the PTAB
“fail[ed] to consider the extensive extrinsic and full intrin-
sic evidence” detailing how a PHOSITA would understand
that solder pads were capable of attachment via reflow,
Appellant’s Br. 72; see id. at 71, and that the PTAB im-
properly considered “other methods of soldering” in its
analysis, id. at 73. We disagree with Knowles.
    Substantial evidence supports the PTAB’s determina-
tion that the specification does not provide adequate
written description to allow a PHOSITA to recognize that
the inventor invented what is claimed. As an initial
matter, Knowles does not contend that the specification
KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.                 13



identifies the “solder reflow process” as a means of con-
necting solder pads to the circuit board. The ’231 patent’s
specification states that the “substrate . . . further com-
prises solder pads 31 for electrical connection to an end
user’s board.” ’231 patent col. 4 ll. 2−4. The specifica-
tion’s only other reference to solder pads states that “the
leads are formed by plating a through-hole in a circuit
board of which one half will eventually form the pathway
to the solder pad.” Id. col. 3 ll. 12−14. The specification
thus does not require solder pads to connect to the circuit
board by any particular process, including the solder
reflow process. Moreover, Knowles does not contest that
other processes for attaching solder pads were known in
the art at the time of the invention and submitted as
evidence before the PTAB, and those processes could have
been used to form the complete circuit board according to
the details in the specification. See Appellant’s Br. 71−73
(recognizing other methods of soldering); J.A. 656−86,
2534−42 (same); see also Cirrus I, 2015 WL 5272691, at *7
(“We instead find that solder reflow is but one of multiple
specific methods or species for connecting solder pads to a
printed circuit board.”). Substantial evidence thus sup-
ports the PTAB’s determination that the ’231 patent fails
to provide adequate written description for the reflow
process limitation.
     Knowles’s counterarguments are unpersuasive. First,
Knowles contends that the PTAB disregarded “the state of
the art at the time of filing” and “prior art knowledge”
that would have demonstrated that a PHOSITA knew
solder pads were “intended to be capable of reflow at-
tachment to a user’s board.” Appellant’s Br. 65, 66 (quot-
ing Ariad Pharm., 598 F.3d at 1358); see id. at 66−67
(listing prior art references that disclose solder reflow as a
well-known process of connecting mount devices).
Knowles misunderstands the PTAB’s analysis. The PTAB
acknowledged that solder reflow was a process of connect-
ing a board to a solder pad but found that other processes
14                 KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.



of connection existed in the prior art. Therefore, the ’231
patent’s specification, detailing only the broad idea of
solder pads connected to the circuit board, “fail[e]d com-
pletely to disclose the newly claimed species of such
pads―pads that are connectable to a board specifically by
using a reflow process.” Cirrus II, 2016 WL 1378707, at
*7; see Cirrus I, 2015 WL 5272691, at *8. The parties
presented conflicting views of the knowledge of a
PHOSITA and disputed whether such a person would
have understood solder reflow to be the only (or even the
primary) way to connect solder pads to a printed circuit
board. Given these uncertainties and at best a passing
reference to solder pads in the specification, the PTAB
reasonably found that a PHOSITA would not have recog-
nized that the inventor possessed solder pads “configured
to” connect to a printed circuit board through a reflow
process.
     Second, Knowles states that the specification’s de-
scription of the solder pads “on the bottom of the inven-
tor’s package” would make clear to a PHOSITA that the
pads would necessarily attach to a user’s board via solder
reflow. Appellant’s Br. 69; see id. at 68−70. The PTAB
reviewed Knowles’s arguments and found them unper-
suasive because Knowles did not contend that the specifi-
cation necessarily disclosed a solder reflow process.
Cirrus I, 2015 WL 5272691, at *7 (citing J.A. 5199−201);
see J.A. 5201 (stating, in Knowles’s brief to the PTAB,
only that solder pads located on the bottom of the sub-
strate “could use” the solder reflow process); see also
Cirrus II, 2016 WL 1378707, at *6−7 (finding Knowles’s
arguments that solder pads “on the bottom” of the pack-
age would be used to mount a device through solder
reflow “not persuasive” because, inter alia, the considera-
tion for adequate written description asks what the
applicant conveyed with reasonable clarity, and the ’231
patent “failed to even mention, much less spell out any
detail of, the claimed reflow process”).
KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.               15



    Knowles on appeal similarly fails to present evidence
on the location of the pads sufficient to render the PTAB’s
findings unsupported. Knowles cites the single line of the
specification disclosing solder pads generally, Appellant’s
Br. 69 (citing ’231 patent col. 4 ll. 2−4), Figure 3 of the
’231 patent showing the location of solder pads, id., and a
line from the specification that the inventor chose pack-
age elements to achieve “a better match of thermal coeffi-
cients,” id. (quoting ’231 patent col. 3 ll. 4−8). As we
stated above, the single line disclosure of solder pads in
the specification is insufficient to disclose the claimed
solder reflow process. Moreover, the line discussing
“thermal coefficients” relates to the material used for
connecting the package to a circuit board and, without
more, does not disclose any particular means of connec-
tion for the solder pads. Knowles cites to a line in the
specification that the disclosed package will produce a
“smaller” footprint than typical models that use a “gull
wing configuration” because the “leads are formed by
plating a through-hole in a circuit board of which one half
will eventually form the pathway to the solder pad.” ’231
patent col. 3 ll. 12−16; see Appellant’s Br. 69. Again, this
description does not mention solder reflow, and Knowles
has not presented evidence that through-hole plating is
commonly understood to include solder reflow. See Appel-
lant’s Br. 50−52, 66−67 (distinguishing through-hole
plating from surface mounting and arguing that solder
reflow is a type of surface mounting). See generally id.
For these reasons, we are not persuaded by Knowles’s
argument. See Lockwood v. Am. Airlines, Inc., 107 F.3d
1565, 1572 (Fed. Cir. 1997) (“It is not sufficient for pur-
poses of the written description requirement of § 112 that
the disclosure, when combined with the knowledge in the
art, would lead one to speculate as to the modifications
that the inventor might have envisioned, but failed to
disclose.”).
16                  KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.



     Finally, Knowles alleges that the PTAB incorrectly
required that the specification disclose a “process” of
solder reflow for “apparatus claims.” Appellant’s Br. 73,
74. Knowles cites Microprocessor Enhancement Corp. v.
Texas Instruments, to argue that the correct legal stand-
ard for finding an adequate written description of an
apparatus claim asks only whether the apparatus is
“capable of performing the recited functions.” Id. at 74
(citing 520 F.3d 1367, 1375 (Fed. Cir. 2008)). Knowles’s
cited portion of Microprocessor is not an analysis of the
written description requirement under § 112; rather, it
relates to whether a claim term used repeatedly in a
patent’s claims was “insolubly ambiguous,” rendering the
claims indefinite under the standard then applicable. 520
F.3d at 1374; see Nautilus, Inc. v. Biosig Instruments,
Inc., 134 S. Ct. 2120, 2124 (2014) (describing change in
the standard). These statements simply do not apply
here.
     Because the PTAB correctly identified and applied the
applicable legal standard for lack of written description as
recited by this court in Enzo Biochem, Inc. v. Gen-Probe
Inc., and its progeny, see Cirrus II, 2016 WL 1378707, at
*6 (citing 323 F.3d 956, 969 (Fed. Cir. 2002), and explain-
ing that “[t]he test for whether an applicant’s specification
contains adequate written description for the claimed
subject matter is whether applicant conveyed with rea-
sonable clarity to those skilled in the art that, as of the
filing date sought, applicant was in possession of the
invention”); Cirrus I, 2015 WL 5272691, at *6−8 (discuss-
ing Enzo and subsequent written description cases), we
see no reason to disturb the PTAB’s holding on this basis.
                III. Third-Party Requesters
    The original petitions for inter partes reexamination
in this case were filed by three third-party requesters.
See Cirrus I, 2015 WL 5272691, at *1. Two of the three
third-party requesters dropped out of the case on appeal.
KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.                17



See Non-Participation Letter from Analog Devices, Inc.,
ECF No. 3; Change of Caption to Remove BSE Co., Ltd.,
ECF No. 18. The third, Wolfson Microelectronics plc.
(“Wolfson”), was replaced by Cirrus Logic, Inc. and Cirrus
UK Ltd. (together, “the Cirrus entities”) as real parties-in-
interest. See J.A. 14374−76 (Notice of Change in Real
Party-in-Interest), 14418−20 (Supplemental Notice of
Change in Real Party-in-Interest). Before the PTAB, the
Cirrus entities were added as parties of record midway
through proceedings but denied their request to partici-
pate in the oral hearing for the request to rehear Cirrus I
based on untimely filing. J.A. 14434−41. The decision
denying participation at the oral hearing further stated
that, if the Cirrus entities chose to attend the hearing, the
panel would have discretion to “ask [the Cirrus entities]
any questions that they may have with regard to either
the appeal or the Notice of Change in real party-in-
interest.” J.A. 14440.
     In contesting the Cirrus entities’ tardy request to par-
ticipate in the oral hearing, Knowles, among other things,
questioned whether the Cirrus entities were a proper
party to the proceeding. J.A. 14409−14 (Opposition to
Cirrus[’s] Petition to Waive or Suspend Rules); see
J.A. 14411 (“[The Cirrus entities’] filing does not explain
how the Cirrus [e]ntities are entitled to take over for the
Requester, Wolfson . . . .”). Although the PTAB did not
allow the Cirrus entities to participate in the oral hearing
based on their untimely filing, see J.A. 14439, the PTAB
allowed the overall change in real party-in-interest for the
case to proceed without comment. 8 Before the PTAB,



    8  “Generally, the [USPTO] will not look beyond the
required statement identifying the real party in interest,”
but if the statement is ambiguous or inaccurate, “[a]
persuasive response . . . that asserts that the request
18                  KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.



Knowles only contested the Cirrus entities’ participation
at the oral hearing, not the decision to add the Cirrus
entities to the inter partes reexamination. See Oral Arg.
at 19:57−20:10, http://oralarguments.cafc.uscourts.gov/
default.aspx?fl=2016-2010.mp3 (“The best argument I
have on that . . . is I believe my client feels like it raised
the objection below and at the first instance here on
appeal we raised the objection.”); see also id. at
18:53−19:23 (“[The Cirrus entities were not] permitted to
participate at the oral argument. I guess our view was by
that time we had prevailed on the issue of whether or not
they could participate . . . . To us, it had been decided in
our favor . . . that seems like a decision on the mer-
its . . . that they weren’t the proper party in the case.”).
Although Knowles now argues that it was not allowed to
contest the entry of appearance below, id. at 18:23−52,
Knowles offers no evidence to support this statement.
Only after the PTAB issued its decision on appeal and
denial of a request for rehearing, and Knowles appealed
to this court, did Knowles challenge the entry of the
Cirrus entities as proper parties to the case. See Order,
ECF No. 32 (denying Knowles’s motion to remand the
case for additional proceedings on the question of real
parties-in-interest). As such, we find this argument
waived. 9 See Singleton v. Wulff, 428 U.S. 106, 120 (1976).




named the proper real party . . . would establish that as
filed, there was no facial inaccuracy or ambiguity in such
identification.” In re Guan, No. 95/001,045, 2008 WL
10682851, at *7 (P.T.A.B. May 26, 2008). The Cirrus
entities appear to have complied with these requirements,
as the USPTO never sought further clarification.
     9   Because we decline to review this argument, we
deny Knowles’s motion to strike, pursuant to Federal
Circuit Rule 27(e), all references to extra-record materials
KNOWLES ELECS. LLC   v. CIRRUS LOGIC, INC.             19



                        CONCLUSION
    We have considered Knowles’s remaining arguments
and find them unpersuasive. Accordingly, the Decision on
Appeal of the U.S. Patent and Trademark Office’s Patent
Trial and Appeal Board is
                        AFFIRMED
                            COSTS
   No costs.




in the Cirrus entities’ brief, argument, and appendix. See
Reply Br. 34.
  United States Court of Appeals
      for the Federal Circuit
                 ______________________

           KNOWLES ELECTRONICS LLC,
                   Appellant

                            v.

       CIRRUS LOGIC, INC., CIRRUS LOGIC
          INTERNATIONAL (UK) LTD.,
                    Appellees
             ______________________

                       2016-2010
                 ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in Nos. 95/000,509,
95/001,251, 95/001,363.
                 ______________________
NEWMAN, Circuit Judge, dissenting.
    I write in concern for perpetuation of the erroneous
position that the PTAB need not apply the prior final
judicial decision of the same issue of the same claims of
the same patent. 1 This error not only produces an incor-
rect result in this case, but will further impart uncertain-


   1   Cirrus Logic Inc. v. Knowles Elecs. LLC,
No. 15-4342, 2015 WL 5272691 (P.T.A.B. Sept. 8, 2015)
(“PTAB Op.”); Cirrus Logic Inc. v. Knowles Elecs. LLC,
No. 15-4342, 2016 WL 1378707 (P.T.A.B. Apr. 5, 2016)
(“PTAB Rehearing Op.”).
2            KNOWLES ELECTRONICS LLC    v. CIRRUS LOGIC, INC.



ty to proceedings under the America Invents Act. The
purpose whereby the PTAB was created as an agency
tribunal, in order to provide stable law and economical
determination of patent validity, is negated when final
adjudication in a court of last resort may be ignored, and
the issue litigated afresh in the agency tribunal.
    The Supreme Court has recognized, “courts may take
it as given that Congress has legislated with the expecta-
tion that the principle [of issue preclusion] will apply
except when a statutory purpose to the contrary is evi-
dent.” B & B Hardware, Inc. v. Hargis Indus., Inc., 135 S.
Ct. 1293, 1303, 1305–06 (2015) (alteration in original)
(quoting Astoria Fed. Sav. & Loan Ass’n v. Solimino, 501
U.S. 104, 108 (1991)). A prior judicial decision resolving
the same issue is accorded preclusive effect not only in
subsequent court proceedings but also before an adminis-
trative agency, subject only to the established equitable
and due process exceptions to preclusion.
    However, the PTAB stated that “precedent makes
clear that the USPTO is not bound in reexamination
proceedings by claim constructions produced by a court.”
PTAB Op. *12. While precedent has previously addressed
the effect of a prior district court claim construction on a
subsequent PTO proceeding, never before has a final
claim construction by this court been held not to be pre-
clusive.
    Here the claim construction was decided by the Fed-
eral Circuit, as a matter of law, in MEMS Technology
Berhad v. International Trade Commission, 447 F. App’x
142 (Fed. Cir. 2011). No equitable or due process excep-
tion to issue preclusion is here asserted; thus preclusion
should apply. The majority declines to discuss this ques-
tion, which is presented on this appeal. By this silence,
my colleagues are reinforcing this incorrect position. I
respectfully dissent.
KNOWLES ELECTRONICS LLC   v. CIRRUS LOGIC, INC.          3



Federal Circuit Decisions on the Same Patent
Should Apply in Subsequent PTAB Proceedings
    The PTAB states that “precedent makes clear that the
USPTO is not bound in reexamination proceedings by
claim constructions produced by a court.” PTAB Op. *12.
The Federal Circuit, through silence, endorses this irregu-
larity. However, judicial resolution of a question of law
cannot be ignored. The result, as here illustrated, is
duplicate proceedings in the courts and the PTO, inhibit-
ing finality of judicial determinations in areas subject to
the America Invents Act.
      In this case, the PTAB declined to apply the Federal
Circuit’s prior decision construing the same term of the
same claims of the same patent, citing precedent that had
previously been directed to district court decisions. PTAB
Op. *12 (citing In re Trans Tex. Holdings Corp., 498 F.3d
1290, 1301 (Fed. Cir. 2007) (“We conclude that the Board
was not bound by the district court’s claim construction
. . . .”)).
    The panel majority declines to consider whether the
PTAB is bound by the Federal Circuit’s decision on the
same patent in MEMS Technology Berhad v. Internation-
al Trade Commission, 447 F. App’x 142 (Fed. Cir. 2011).
Instead, the panel majority condones the PTAB’s conduct
of a full trial of the same issue, stating that this court
only “reviews the reasonableness of the [US]PTO’s dis-
puted claim term interpretations,” Maj. Op. 5, in disre-
gard of the Federal Circuit’s prior interpretation of the
same claim term in MEMS Technology.
    The purpose of the America Invents Act is to provide a
more efficient and less costly post-grant determination of
certain validity issues, compared with the time and cost of
court litigation. Such purpose is negated by duplicate
PTO litigation of the same question after prior final
judicial decision. Such duplicate proceeding is appropri-
ately governed by the principles of collateral estoppel, as
4            KNOWLES ELECTRONICS LLC    v. CIRRUS LOGIC, INC.



summarized in Sections 27–29 of the Restatement (Sec-
ond) of Judgments (Am. Law Inst. 1982). As discussed by
the Supreme Court in United States v. Mendoza, the
Court stated:
    Under the judicially-developed doctrine of collat-
    eral estoppel, once a court has decided an issue of
    fact or law necessary to its judgment, that deci-
    sion is conclusive in a subsequent suit based on a
    different cause of action involving a party to the
    prior litigation. Montana v. United States, 440
    U.S. 147, 153 (1979). Collateral estoppel, like the
    related doctrine of res judicata, serves to “relieve
    parties of the cost and vexation of multiple law-
    suits, conserve judicial resources, and, by prevent-
    ing inconsistent decisions, encourage reliance on
    adjudication.” Allen v. McCurry, 449 U.S. 90, 94
    (1980).
464 U.S. 154, 158 (1984) (footnote omitted). The Court
summarized the principles of non-mutual collateral
estoppel:
    In furtherance of those policies, this Court in re-
    cent years has broadened the scope of the doctrine
    of collateral estoppel beyond its common law lim-
    its. Ibid. [Allen v. McCurry, 449 U.S. at 94.] It
    has done so by abandoning the requirement of
    mutuality of parties, Blonder-Tongue Laborato-
    ries, Inc. v. University of Illinois Foundation, 402
    U.S. 313 (1971), and by conditionally approving
    the “offensive” use of collateral estoppel by a non-
    party to a prior lawsuit. Parklane Hosiery [Co. v.
    Shore, 439 U.S. 322 (1979)].
Mendoza, 464 U.S. at 158.
    In Trans Texas, on appeal from an ex parte PTO reex-
amination decision, this court declined to apply issue
preclusion, stating that the PTO was not a party to the
KNOWLES ELECTRONICS LLC   v. CIRRUS LOGIC, INC.            5



district court infringement litigation where the same term
was construed. 498 F.3d at 1296–98. Both Trans Texas
and the more recent Power Integrations case dealt with a
prior district court decision, not a prior final decision of
the Federal Circuit. See Power Integrations, Inc. v. Lee,
797 F.3d 1318, 1326–27 (Fed. Cir. 2015) (stating that the
PTAB should address but is not bound by the previous
judicial claim construction).
    This conflict between court decision and agency obli-
gation raises issues of litigation and patent policy, as well
as invoking the fundamentals of stare decisis and separa-
tion of powers. The adjudication of questions of patent
law takes on special significance in light of the purposes
of the America Invents Act. The purposes of efficiency,
economy, and finality of patent review are lost when
judicial determination of the same question of patentabil-
ity has been completed, including appeal to and decision
by the Federal Circuit—yet the decision is ignored and
the proceeding repeated by the administrative agency and
again appealed to the Federal Circuit; and where, as here,
the Federal Circuit reaches a contrary decision.
    In B & B Hardware, Inc. v. Hargis Industries, Inc.,
135 S. Ct. 1293 (2015), the Court approved of issue pre-
clusion arising from a decision of the Trademark Trial
and Appeal Board, in later proceedings on the same issue
in a court. The Court explained reciprocity of issue pre-
clusion, and that a court may be precluded by a prior
agency decision, just as an agency is precluded by a prior
court decision. The Court stated:
        Both this Court’s cases and the Restatement
    make clear that issue preclusion is not limited to
    those situations in which the same issue is before
    two courts. Rather, where a single issue is before
    a court and an administrative agency, preclusion
    also often applies. Indeed, this Court has ex-
    plained that because the principle of issue preclu-
6            KNOWLES ELECTRONICS LLC   v. CIRRUS LOGIC, INC.



    sion was so “well established” at common law, in
    those situations in which Congress has authorized
    agencies to resolve disputes, “courts may take it
    as given that Congress has legislated with the ex-
    pectation that the principle [of issue preclusion]
    will apply except when a statutory purpose to the
    contrary is evident.”
Id. at 1303 (alteration in original) (quoting Astoria, 501
U.S. at 108). These principles are recorded in the Re-
statement (Second) of Judgments § 83(1), stating that
with limits, “a valid and final adjudicative determination
by an administrative tribunal has the same effects under
the rules of res judicata, subject to the same exceptions
and qualifications, as a judgment of a court.” See also id.
§ 83 cmt. f (defining res judicata to include both the
doctrines of claim preclusion and issue preclusion).
    The Court in B & B Hardware further recited that a
district court’s prior determination is binding in TTAB
proceedings involving the same issue:
    Neither is issue preclusion a one-way street.
    When a district court, as part of its judgment, de-
    cides an issue that overlaps with part of the
    TTAB’s analysis, the TTAB gives preclusive effect
    to the court’s judgment.
135 S. Ct. at 1305–06; see also id. at 1309–10 (procedural
differences between TTAB proceedings and courts do not
negate issue preclusion).
    Nothing in the America Invents Act suggests a legis-
lative intent to depart from this precedent, and to take
the unusual step of excusing the PTO from the rules of
preclusion and the effect of prior judicial determination.
Here the PTAB, citing this court’s ruling in Trans Texas,
held that no preclusion arose from the Federal Circuit’s
decisions concerning the same patent in MEMS Technolo-
gy. PTAB Op. *12. My colleagues on this panel find “no
KNOWLES ELECTRONICS LLC   v. CIRRUS LOGIC, INC.             7



inconsistency with the PTAB’s construction of the claim
term ‘package’ here,” Maj. Op. 10, although the construc-
tions are dispositively inconsistent. And while Power
Integrations, 797 F.3d at 1326–27, related to the district
court’s claim construction, until today no precedent has
held that the Federal Circuit’s claim construction has no
preclusive effect.
    I suggest that the “consisten[cy]” mentioned in Power
Integrations is the wrong inquiry. The question is wheth-
er the PTAB decision is precluded by the prior judicial
decision, and whether any equitable or due process excep-
tion to preclusion may apply. See B & B Hardware, 135
S. Ct. at 1298, 1303. Material to this determination is the
purpose of the America Invents Act to provide “a quick
and cost effective alternative to litigation.” H.R. Rep. 112-
98, pt. 1 at 48 (2011). See also Patent Reform: The Future
of American Innovation: Hearing Before the Senate Comm.
on the Judiciary, 110th Cong. 7 (2007), where PTO Direc-
tor Jon W. Dudas explained the role of this proposed new
agency tribunal:
        The idea was that this could serve as a mean-
    ingful alternative to litigation, probably less cost-
    ly, certainly before experts at the Patent and
    Trademark Office. We also thought that it is very
    important if you are going to have a second win-
    dow, if you are going to have a post-grant review,
    that you have very real estoppel, that you have a
    choice between litigation and post-grant review,
    that we should not have a situation where we set
    up forum shopping or giving several bites at the
    apple, that there should be true estoppel.
To achieve this purpose, the AIA included the proposed
estoppel whereby an agency decision would finally re-
solve, between the parties, certain issues previously
subject only to litigation. However, when litigation has
already occurred and been appealed to finality, an ensu-
8            KNOWLES ELECTRONICS LLC    v. CIRRUS LOGIC, INC.



ing PTAB proceeding is not only redundant—it negates
the statutory purposes of efficiency, cost savings, and
finality.
    The issue of claim construction is a question of law.
See Teva Pharm. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831,
836–38, 841–42 (2015) (stating that “the ultimate ques-
tion of construction will remain a legal question”); Mark-
man v. Westview Instruments., Inc., 517 U.S. 370, 390–91
(1996) (stating the “importance of uniformity in the
treatment of a given patent” and “treating interpretive
issues as purely legal will promote (though it will not
guarantee) intrajurisdictional certainty”). Questions of
law must be correctly decided, whatever the tribunal.
    Collateral estoppel is naturally subject to equitable
principles, including exceptions and policy considerations.
See Restatement (Second) of Judgments §§ 28–29 (report-
ing “Exceptions to the General Rule of Issue Preclusion”
and discussing non-mutual “Issue Preclusion in Subse-
quent Litigation with Others”); see also Parklane Hosiery
Co. v. Shore, 439 U.S. 322, 329–31 (1979) (reasons of
policy and equity as limits on non-mutual collateral
estoppel).
     A primary purpose of collateral estoppel in the patent
context is the final and uniform resolution of validity
issues. In Miken Composites, L.L.C. v. Wilson Sporting
Goods Co., the court “note[d] that the claim construction
affirmed in this case is fully consistent with the interpre-
tation given to the same limitation” in prior litigation,
and that doing otherwise “would run counter to the Su-
preme Court’s guidance on stare decisis in Markman.”
515 F.3d 1331, 1338 n.* (Fed. Cir. 2008); see also Key
Pharm. v. Hercon Labs. Corp., 161 F.3d 709, 716 (Fed.
Cir. 1998) (“We do not take our task lightly in this regard,
as we recognize the national stare decisis effect that this
court’s decisions on claim construction have.”).
KNOWLES ELECTRONICS LLC   v. CIRRUS LOGIC, INC.          9



    A purpose of the AIA is to save time and cost, not to
double it. The judicial obligation is to implement the
statutory purpose. Guided by the Court, both mutual and
non-mutual collateral estoppel must be considered. Thus
I do not join my colleagues’ implicit holding that the
PTAB is not bound by the final Federal Circuit decision in
MEMS Technology, on the same term of the same claims
of the same patent. Where no cogent reason to reject the
prior construction of a claim term is presented, no devia-
tion should be permitted. See Markman, 517 U.S. at 390–
91 (recognizing the need for “uniformity in the treatment
of a given patent”).
    In MEMS Technology the Federal Circuit, on appeal
of an ITC determination, construed the term “package” in
the claimed microelectromechanical system as “a self-
contained unit that has two levels of connection, to the
device and to a circuit (or other system),” 447 F. App’x at
159, reasoning that “[t]he requirement that the compo-
nents listed in the claim body come together to form a
mountable package is [ ] an important characteristic of
the claimed invention.” Id. at 154 (internal quotation
marks omitted). The PTAB here adopted a somewhat
different construction of “package,” as “requir[ing] a
second-level mechanical and electrical connection,” but
“need not possess a second-level connection to a printed
circuit board that is made specifically by either through-
hole mounting or surface mounting. Rather, a package
may be connected to an external component such as a
wiring board or printed circuit board by any electro-
mechanical means.” PTAB Op. *9, *12. The difference
between these constructions may not appear to be large,
but the PTAB’s construction sufficed to hold claims 1–4
invalid on the ground of anticipation whereas the Federal
Circuit’s construction sustained validity on the ground of
anticipation.
    The panel majority holds that the PTAB “properly
construed the claim term ‘package,’” and does not discuss
10           KNOWLES ELECTRONICS LLC   v. CIRRUS LOGIC, INC.



whether the PTAB is required to follow the prior Federal
Circuit construction. Maj. Op. 10–11. Judicial finality is
not so easily cast aside. On the position that collateral
estoppel does not arise in patent cases, neither the pa-
tentee nor the public can rely on judicial determination of
an issue that might later be taken to the PTAB. This
court should recognize the significant legal and economic
consequences of conflict between judicial ruling and
agency decision, in which patent life and investment
resources are consumed in duplicate litigation, with no
reliable finality.
    The America Invents Act created a unique balance of
administrative process and judicial determination, in
service to the public benefit of technologic advance.
Achieving the optimum balance is critical. The issue of
preclusion flagged herein warrants resolution.
