Court Opinion

ID: 4199980
Source: CourtListenerOpinion
Date Created: 2017-08-30 15:01:29.57084+00
Date Added: 2024-06-11T09:24:04.333919
License: Public Domain

United States Court of Appeals
      for the Federal Circuit
                ______________________

              VICOR CORPORATION,
                    Appellant

                           v.

                   SYNQOR, INC.,
                       Appellee
                ______________________

                      2016-2283
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 95/001,861.

       -----------------------------------

                   SYNQOR, INC.,
                     Appellant

                           v.

              VICOR CORPORATION,
                      Appellee
               ______________________

                      2016-2288
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 95/001,637.
2                                VICOR CORP.   v. SYNQOR, INC.

                 ______________________

                Decided: August 30, 2017
                 ______________________

   MATTHEW A. SMITH, Smith Baluch LLP, Washington,
DC, argued for Vicor Corporation. Also represented by
ANDREW T. D’AMICO, JR., Vicor Corporation, Andover, MA;
LAWRENCE K. KOLODNEY, Fish & Richardson, PC, Boston,
MA.

    THOMAS D. REIN, Sidley Austin LLP, Chicago, IL, ar-
gued for SynQor, Inc. Also represented by CONSTANTINE
L. TRELA, JR., BRYAN C. MULDER.
                 ______________________

     Before LOURIE, TARANTO, and CHEN, Circuit Judges.
CHEN, Circuit Judge.
    SynQor, Inc. (SynQor) owns several patents directed
to a particular architecture for direct current-to-direct
current (DC-DC) power converters, including U.S. Patent
Nos. 8,023,290 (the ’290 patent) and 7,272,021 (the ’021
patent) (hereinafter, we refer to the ’290 and ’021 patents
collectively as the SynQor Patents). Vicor Corporation
(Vicor) requested, and the Patent and Trademark Office
(PTO) granted, inter partes reexaminations of the SynQor
Patents. The reexaminations were ultimately decided by
the Patent Trial and Appeal Board (Board), which was
confronted with many proposed rejections and highly
technical competing arguments.          Vicor appeals the
Board’s decision in the ’290 patent’s reexamination hold-
ing that certain claims are patentable over prior art
combinations proposed by Vicor. SynQor, for its part,
appeals the Board’s decision in the ’021 patent’s reexami-
nation holding that certain claims in that patent are
unpatentable as anticipated or obvious.
VICOR CORP.   v. SYNQOR, INC.                              3

     We address these two appeals in a single opinion be-
cause the two patents claim very similar inventions, and
their respective reexaminations share common patenta-
bility issues. Both reexaminations were decided by the
same panel of administrative patent judges. The panel’s
decision in the ’290’s reexamination issued on the same
date as the panel’s decision on rehearing in the ’021’s
reexamination. Despite sharing a common panel and
having opinions issued on the same date, the decisions in
the respective reexaminations contain inconsistent find-
ings on identical issues and on essentially the same
record. We affirm in part, vacate in part, and remand the
Board’s decisions in both reexaminations. 1
                         BACKGROUND
                 I. DC-DC Power Converters
    The SynQor Patents claim systems and methods for
DC-DC power conversion. See generally ’290 patent col.
17 l. 9–col. 18 l. 35; ’021 patent col. 6 l. 21–col. 8 l. 60.
Direct current (DC) flows in only one direction, whereas
alternating current (AC) periodically reverses direction.
AC power supplied from a utility is converted to DC by a
“front end converter.” A DC-DC converter receives the
DC output of a front end converter and transforms it into
one or more lower DC voltages.
    The DC-DC converters at issue in this appeal are de-
signed to drive logic circuitry in large computer and
telecommunications systems that typically require a
number of different power voltages. The claimed convert-
ers perform two general operations in sequence: “isola-
tion” and “regulation.” Isolation converts a DC input into

    1   Related appeal no. 2016-2282, which involves the
reexamination of another SynQor patent (U.S. Patent No.
7,564,702), presents unique issues addressed in a sepa-
rate opinion issued today.
4                                VICOR CORP.   v. SYNQOR, INC.

AC, reduces the AC voltage using a transformer, and
converts AC back to DC at a voltage level lower than the
DC input. Regulation then restricts that isolated output
down to a DC voltage appropriate for driving logic circui-
ty.
                        A. Isolation
    Isolation enhances safety and prevents unwanted
noise by using a transformer to lower voltage without
using wires connecting inputs and outputs. A transform-
er comprises “primary” and “secondary” windings, such as
coiled wires. The transformer’s input is connected to the
primary winding, which transfers electrical energy to the
secondary winding via magnetic fields. The transformer’s
output from the secondary winding is a fraction, or multi-
ple, of the transformer’s input determined by the ratio of
turns in the respective primary and secondary windings.
For example, a transformer with a primary winding that
has twice as many turns as the secondary winding will
have an output voltage that is half of its input.
    Isolation circuitry converts the secondary winding’s
AC output to DC using rectifiers. The SynQor Patents’
claims all require use of “controlled” rectifiers, which use
control signals and circuitry to reverse or prevent the flow
of current in one direction. Embodiments of the SynQor
Patents’ inventions use a particular type of pre-existing
controlled rectifier known as a “synchronous” rectifier,
which uses a waveform of current flow across one of the
transformer’s windings to control switching circuitry that
generates a DC output.
                      B. Regulation
    Regulation circuitry receives an isolated DC output
and regulates it down to appropriate voltage(s) to drive
logic circuitry. Regulation was known to be implemented
using at least two types of regulators: “switching” regula-
tors and “linear” regulators. Switching regulators include
VICOR CORP.   v. SYNQOR, INC.                              5

a transistor-implemented switch, which turns on and off
in response to one or more parameters sensed in the
circuit to maintain output voltage at a predefined value.
Linear regulators regulate an output by varying the
resistance of the regulator.
          C. Prior Art DC-DC Power Converters
    Prior art power architectures for large computer and
telecommunications systems used DC-DC power convert-
ers that integrated isolation and regulation circuitry in
each individual converter. The presence of isolation
circuitry in every converter took up valuable space on
circuit boards where the converters were located, which
could have been used for additional microprocessors,
memory, or logic circuitry.
                     II. SynQor’s Patents
  A. SynQor’s Asserted Improvement over the Prior Art
     The SynQor Patents claim to improve prior art sys-
tems by separating the isolation and regulation function-
ality of DC-DC converters into two steps and using a
single isolation stage to drive multiple regulation stages.
See ’290 patent Fig. 1, col. 4 ll. 40–54; ’021 patent Fig. 5,
col. 5 ll. 6–12. The single isolation stage drives an “in-
termediate bus” that is fed to multiple on-board regulator
components. See -2288 J.A. 1117–19. 2 The regulators can
be smaller, less expensive, and more efficient compared to
regulators used in on-board, integrated isolat-
ing/regulating converters. SynQor portrays this separa-
tion of isolation and regulation stages as the key
invention of the SynQor Patents and “a revolutionary new
power architecture” developed by SynQor’s CEO—Dr.
Martin Schlecht—who is the sole named inventor on the

    2   Filings from the respective appeals are identified
by “-2283” and “-2288.”
6                                  VICOR CORP.   v. SYNQOR, INC.

SynQor Patents. -2288 Open. Br. at 2. According to
SynQor, the new two-stage architecture, which became
known as “Intermediate Bus Architecture” (IBA), was
“hailed in the field, copied by SynQor’s competitors, and
widely adopted by the industry.” Id.
        B. Disputed Claims of the SynQor Patents
     The SynQor Patents’ claims tailor their coverage of
IBA’s general schema by including limitations that re-
quire specific circuit features. First, all of the claims
require separate isolation and regulation stages compris-
ing (1) a “non-regulating” isolation stage and (2) a plurali-
ty of “non-isolating” regulation stages. See generally ’290
patent col. 17 l. 9–col. 18 l. 35; ’021 patent col. 6 l. 21–col.
8 l. 60.
    Second, all claims of the ’290 patent and claims 49–50
of the ’021 patent require the regulation to be done by
switching regulators. See generally ’290 patent col. 17 l.
9–col. 18 l. 35; -2288 J.A. 115 (reciting claims 49–50 of the
’021 patent, added during reexamination). SynQor argues
that switching regulators provide more efficient regula-
tion than linear regulators used in prior art converters.
     Third, for the non-regulating isolation stage, all
claims of the ’021 patent require “substantially uninter-
rupted flow of power” through a transformer’s “primary
and secondary winding circuits.” See generally ’021
patent col. 6 l. 21–col. 8 l. 60. The ’021 patent’s specifica-
tion describes circuitry that regulates the flow of power
across the primary and secondary windings by setting a
“duty cycle” for periodically reversing the directional flow
of current across the primary winding. See id. col. 3 l. 62–
col. 4 l. 18. The ’021 patent explains that power is always
flowing through the isolation stage, except during “brief
switch transitions.” ’021 patent col. 4 ll. 8–11.
    Finally, both patents include dependent claims that
limit input and output voltages to ranges appropriate for
VICOR CORP.   v. SYNQOR, INC.                                7

converters that receive DC power from a front end con-
verter and output DC power to drive logic circuitry. See,
e.g., ’290 patent col. 18 ll. 7–9 (claim 7); ’021 patent col. 7
ll. 40–42 (claim 25). SynQor argues that restricting
circuit operation to these voltage ranges distinguishes
prior art power systems that were not designed for power-
ing telecommunications or computer systems.
    The sole independent claim of the ’290 patent, claim 1,
covers an IBA converter implemented with switching
regulators:
        A DC-DC power converter system providing
    plural regulated DC outputs, each having a regu-
    lated voltage, comprising:
        a DC input;
        a non-regulating isolating converter com-
        prising:
              a primary transformer winding
              circuit having at least one primary
              winding that receives power from
              the DC input; and
              a secondary transformer winding
              circuit having at least one second-
              ary winding coupled to the at least
              one primary winding and having
              plural controlled rectifiers, each
              having a parallel uncontrolled rec-
              tifier and each in circuit with a
              secondary winding, each controlled
              rectifier being turned on and off in
              synchronization with a voltage
              waveform of the at least one pri-
              mary winding to provide a non-
              regulated, isolated DC output; and
8                                VICOR CORP.    v. SYNQOR, INC.

        plural non-isolating switching regula-
        tors, each receiving power from the non-
        regulated, isolated DC output of the non-
        regulating isolating converter and each
        providing one of the regulated DC outputs
        having a regulated voltage.
’290 patent col. 17 ll. 9–30 (emphasis added).
    Claim 7 of the ’290 patent is exemplary of the depend-
ent claims in the SynQor Patents that specify in-
put/output voltage ranges for telecommunications or
computer systems:
        A power converter system as claimed in claim
    1 wherein each regulated voltage of each of
    the regulated DC outputs is of a voltage level
    to drive logic circuitry.
’290 patent col. 18 ll. 7–9 (emphasis added).
    Claim 1 of the ’021 patent is very similar to claim 1 of
the ’290 patent, but includes the “substantially uninter-
rupted flow of power” limitation present in all claims of
the ’021 patent:
        A power converter system comprising:
        a normally non-regulating isolation stage
        comprising:
            a primary winding circuit;
            a secondary winding circuit cou-
            pled to the primary winding cir-
            cuit, the secondary winding circuit
            comprising a secondary trans-
            former winding in series with a
            controlled rectifier having a paral-
            lel uncontrolled rectifier, the sec-
            ondary winding circuit providing a
VICOR CORP.   v. SYNQOR, INC.                             9

              normally non-regulated output of
              the isolation stage; and
              a control circuit which controls du-
              ty cycle of the primary winding
              circuit, the duty cycle causing sub-
              stantially uninterrupted flow of
              power through the primary and
              secondary winding circuits during
              normal operation; and
          a plurality of non-isolating regulation
          stages, each receiving the non-regulated
          output of the isolation stage and regulat-
          ing a regulation stage output.
’021 patent col. 6 ll. 22–39 (emphasis added).
    III. Prior Proceedings Involving SynQor’s Patents
                  A. SynQor’s 2007 Lawsuit
    In 2007, SynQor sued certain of its major competi-
tors—but not Vicor—for infringing five of its patents,
including the ’021 patent and a related patent, U.S.
Patent No. 7,072,190 (the ’190 patent). 3 All of the assert-
ed patents involved IBA, with its separate isolation and
regulation stages. In 2010, a jury found all asserted
claims not invalid and infringed. The defendants ap-
pealed, arguing that, inter alia, there was no substantial
evidence to support the jury’s nonobviousness verdict.
SynQor, Inc. v. Artesyn Techs., Inc., 709 F.3d 1365, 1372,
1374 (Fed. Cir. 2013) (SynQor I). We rejected defendants’
arguments and affirmed because, inter alia, SynQor had
“introduced extensive objective evidence of nonobvious-
ness at trial, including commercial success, industry
recognition, initial (pre-invention) skepticism of experts,

   3      The SynQor Patents trace priority back to the ’190
patent.
10                                 VICOR CORP.   v. SYNQOR, INC.

unexpected results, and copying by competitors.” Id. at
1377. 4 In so holding, we linked this evidence to the IBA
two-stage architecture as claimed in the patents:
      The record links this convincing evidence to the
      claimed invention thus supplying a nexus to the
      claimed intermediate bus architecture. For ex-
      ample, the record shows that even Defendants’
      engineers were highly skeptical of the claimed in-
      vention, at one point describing it as a “whopper
      in terms of technical challenge.” Another engi-
      neer stated “that separating isolation from regula-
      tion . . . almost surely would cost more in dollars,
      efficiency, and board space.” Further, Defendants’
      expert McAlexander admitted that “there is cer-
      tainly an element of commercial success [to
      SynQor’s] architecture,” and SynQor’s expert, Dr.
      Leeb, testified that “there were significant efforts
      [by Defendants] to copy . . . SynQor’s products.”
Id.
          B. Murata’s Reexamination of the ’190 Patent
    In August 2009, one of the defendants in SynQor I,
Murata Manufacturing Co., Ltd., requested inter partes
reexamination of SynQor’s ’190 patent. See Murata Mfg.

      4 Our discussion of the objective evidence appeared
in connection with analysis of U.S. Patent No. 7,269,034
(the ’034 patent). The ’034 patent is a grandparent of the
’290 patent and, like the ’021 patent, claims priority to the
’190 patent. While the claims of the ’034 patent cover a
semi-regulated isolation stage, they still cover IBA’s
general design of separating isolation and final regulation
stages. ’034 patent col. 17 l. 21–col. 20 l. 17. Indeed, all of
SynQor’s patents discussed in this opinion cover IBA,
which was the focus of our objective evidence analysis in
SynQor I.
VICOR CORP.   v. SYNQOR, INC.                             11

Co. v. SynQor, Inc., Reexamination Control No.
95/001,207, 2013 WL 4427009, at *1 (P.T.A.B. Aug. 16,
2013) (Murata). The PTO granted the request and initi-
ated reexamination.      The examiner rejected certain
claims, and SynQor appealed to the Board. SynQor
presented the same objective evidence of secondary con-
siderations discussed in SynQor I to the Board in support
of its nonobviousness arguments. The Board found a
nexus between SynQor’s evidence and the disputed claims
and reversed all examiner rejections, holding that the
challenged claims were patentable over the prior art
combinations proposed by Murata.
        C. Vicor’s Reexamination of the ’190 Patent
     In September 2011, Vicor requested inter partes reex-
amination of the ’190 patent. The PTO granted the
reexamination request and chose to keep Vicor’s reexami-
nation of the ’190 patent separate from Murata’s reexam-
ination. Vicor cited four prior art references in its request
for reexamination: Steigerwald ’090, 5 Steigerwald ’539 6
(collectively, Steigerwald), Cobos, 7 and Pressman. 8 Stei-
gerwald ’090 incorporates Steigerwald ’539 by reference.
The examiner rejected certain claims as anticipated by
Steigerwald. The examiner also rejected claims as obvi-
ous over combinations of the four references. SynQor
appealed to the Board, and the Board sided with SynQor,
reversing all rejections. Vicor appealed.

    5   U.S. Patent No. 5,377,090.
    6   U.S. Patent No. 5,274,539.
    7   J.A. Cobos & J. Uceda, Low Output Voltage
DC/DC Conversion, IEEE 20th Int’l Conf. on Indus.
Elecs., Control and Instrumentation, at 1676–81 (Sep-
tember 5–9, 1994).
    8   Abraham I. Pressman, Switching and Linear
Power Supply, Power Converter Design (1977).
12                                VICOR CORP.   v. SYNQOR, INC.

    We reversed in part, vacated in part, and remanded.
Vicor Corp. v. SynQor, Inc., 603 F. App’x 969, 970 (Fed.
Cir. 2015) (SynQor II). Steigerwald ’090, we held, incor-
porates Steigerwald ’539 by reference, and the combined
reference discloses an alternative embodiment of a power
converting system having a non-regulating isolation stage
and a plurality of non-isolating regulation stages, in
which the uncontrolled rectifiers in Steigerwald ’090 are
replaced with controlled rectifiers from Steigerwald ’539. 9
Id. at 974–75. We concluded that “[t]he combined refer-
ence teaches a single embodiment that anticipates all
elements of representative claim 20” of the ’190 patent,
that is, a two-stage DC-DC power converter system hav-
ing a non-regulating isolation stage and a plurality of
non-isolating regulation stages. Id. We also vacated the
Board’s nonobviousness determinations of the remaining
claims, which relied in part on the same objective evi-
dence of nonobviousness discussed in SynQor I and sub-
mitted to the Board in Murata, and remanded for further
consideration in light of our anticipation decision. Id.
Regarding the objective evidence of nonobviousness, we
instructed the Board to reconsider whether a nexus exists
between the proffered secondary considerations evidence
and the merits of the claimed invention in light of our
conclusion that representative claim 20 is anticipated:
     [T]he teachings of the combined Steigerwald ref-
     erence may be relevant to any objective evidence
     of nonobviousness. For example, commercial suc-
     cess is evidence of obviousness only when there is
     a “nexus . . . between the merits of the claimed in-
     vention and evidence of commercial success.” Iron

     9  We refer to “Steigerwald” hereinafter as this al-
ternative embodiment incorporating Steigerwald ’539’s
controlled rectifiers into Steigerwald ’090’s DC-DC power
converter circuit.
VICOR CORP.   v. SYNQOR, INC.                           13

   Grip Barbell Co. v. USA Sports, Inc., 392 F.3d
   1317, 1324 (Fed. Cir. 2004). Vicor should have the
   opportunity to argue that SynQor’s evidence of
   commercial success is attributable not to the
   claimed invention, but to the prior art converter
   taught by the combined Steigerwald references.
SynQor II, 603 F. App’x at 975–76. 10
    Representative claim 20 of the ’190 patent, which we
held was anticipated in SynQor II, covers a very similar
invention to those of the currently disputed claims of the
SynQor Patents in the present appeals. Claim 20 recites:
        A power converter system comprising:
        a DC power source;
        a non-regulating isolation stage compris-
        ing:
              a primary transformer winding
              circuit having at least one primary
              winding connected to the source;
              and
              a secondary transformer winding
              circuit having at least one second-
              ary winding coupled to the at least

   10    On remand from our decision in SynQor II, the
Board issued a decision—on the same date that it issued a
decision in the ’290’s reexamination and a decision on
rehearing in the ’021’s reexamination—holding that all
challenged claims of the ’190 patent were unpatentable.
The Board held that the objective indicia evidence was
insufficient to overcome the examiner’s other cited evi-
dence of obviousness, despite finding a nexus between the
objective indicia evidence and the claims of the ’190
patent.
14                               VICOR CORP.   v. SYNQOR, INC.

           one primary winding and having
           plural controlled rectifiers, each
           having a parallel uncontrolled rec-
           tifier and each connected to a sec-
           ondary winding, each controlled
           rectifier being turned on and off in
           synchronization with the voltage
           waveform across a primary wind-
           ing to provide an output; and
       a plurality of non-isolating regulation
       stages, each receiving the output of the
       isolation stage and regulating a regulation
       stage output.
’190 patent col. 18 ll. 29–44. The disputed claims of the
SynQor Patents cover the same two-stage power converter
system, with the addition of limitations directed to, for
example, (1) switching regulators in all claims of the ’290
patent and claims 49–50 of the ’021 patent, (2) substan-
tially continuous power flow across transformer windings
in all claims of the ’021 patent (which replaces language
in claim 20 of the ’190 patent reciting “being turned on
and off in synchronization with the voltage waveform
across a primary winding”), and (3) input/output voltage
range limitations in various dependent claims of both
patents.
 IV. Vicor’s Reexaminations of the ’290 and ’021 Patents
                  (the Present Appeals)
           A. Reexamination of the ’290 Patent
    Vicor requested reexamination of the ’290 patent in
December 2011. The PTO granted the request and adopt-
ed Vicor’s proposed grounds for rejection. Rejections I–II
held that claims 1–15 were obvious over Steigerwald ’090,
Cobos, and Pressman. Rejections III–IV held that the
VICOR CORP.   v. SYNQOR, INC.                             15

same claims were obvious over JP ’446, 11 Steigerwald
’539, and Kassakian. 12 Rejections V–VI held that the
same claims were obvious over Steigerwald and Press-
man. After the Board issued its Murata decision on the
’190 patent, the examiner withdrew all rejections and
adopted the Murata Board’s positions that (1) Steigerwald
’090 and Cobos could not be combined for rejections I–II
because of frequency incompatibility between the refer-
ences’ circuits, (2) a person of ordinary skill in the art
would not have been motivated to combine Steigerwald
and Pressman for rejections V–VI because Steigerwald
taught away from incorporating Pressman’s switching
regulators, and (3) all challenged claims were “not obvious
based on objective indicia of non-obviousness.” See -2283
J.A. 417-18 (citing Murata, -2283 J.A. 1709-45). With
respect to rejections III–IV, the examiner relied exclusive-
ly on evidence of secondary considerations in withdrawing
the rejections involving Vicor’s proposed combination of
JP ’446, Steigerwald ’539, and Kassakian, without ad-
dressing the remaining three factors set forth in Graham
v. John Deere Co. of Kansas City: (1) “the scope and
content of the prior art,” (2) “differences between the prior
art and the claims at issue,” and (3) “the level of ordinary
skill in the pertinent art.” 383 U.S. 1, 17 (1966). Vicor
appealed to the Board.
    The Board affirmed the examiner. Regarding pro-
posed rejections I–II, the Board held that a person skilled
in the art would not have been motivated to combine
Cobos’s controlled rectifiers with Steigerwald ’090’s circuit
because of frequency incompatibilities between the refer-
ences’ circuits, crediting Dr. Schlecht’s testimony on this

    11 Japanese Patent App. Pub. No. H05-64446.
    12 John G. Kassakian & Martin F. Schlecht, High-
Frequency High-Density Converters for Distributed Power
Supply Systems, 76 Proc. IEEE 362 (Apr. 1988).
16                               VICOR CORP.   v. SYNQOR, INC.

issue. 13 As to proposed rejections III–IV, the Board
affirmed the examiner’s decision to withdraw the rejec-
tions based solely on the objective evidence. For proposed
rejections V and VI, the Board adopted the Murata
Board’s determination that there was no motivation to
combine Steigerwald and Pressman because Pressman’s
switching regulators would introduce inductance into the
conductive path of Steigerwald’s output, in contravention
of statements in the Steigerwald patents’ prosecution
history discouraging inclusion of inductance in the out-
put’s path.
    During Vicor’s reexamination of the ’290 patent,
SynQor presented much of the same objective evidence of
nonobviousness that it had presented in SynQor I, in the
Murata reexamination, and in SynQor II. The Board
found SynQor’s arguments regarding the objective evi-
dence to be persuasive and adopted the analysis of sec-
ondary considerations set out in Murata. Although the
Board acknowledged our decision in SynQor II, the Board
did not address SynQor II’s finding that the basic IBA
architecture recited in the claims was already known in
the art. The Board concluded that all disputed claims of
the ’290 patent were patentable over the prior art pre-
sented by Vicor.
           B. Reexamination of the ’021 Patent
    Vicor requested reexamination of the ’021 patent in
May 2011. The PTO granted the request and adopted
Vicor’s proposed rejections. SynQor added new claims
49–50 during the reexamination, which required use of
switching regulators. Rejection I held that claims 1, 9, 15,
21, 24, 26, 31, 39, 45, and 47 were anticipated by Stei-
gerwald. Rejection II held that claims 22, 23, 25, and 27–

     13Proposed rejections I–II did not rely on Stei-
gerwald or Pressman for disclosure of controlled rectifiers.
VICOR CORP.   v. SYNQOR, INC.                            17

30 were obvious over Steigerwald in view of the
knowledge of a person skilled in the art. Rejection III
held that claim 49 was obvious over Steigerwald and
Pressman. Rejection IV held that claim 50 was obvious
over Steigerwald, Pressman, and admitted prior art. The
examiner maintained all rejections and issued a right of
appeal notice. SynQor appealed.
    In this reexamination, the Board affirmed all rejec-
tions. Regarding rejection I, the Board affirmed anticipa-
tion by Steigerwald, finding, inter alia, that substantially
uninterrupted power flowed through the windings of
Steigerwald ’090’s transformer. For rejection II, the
Board affirmed the examiner’s finding that the claimed
input and output voltage ranges would have been obvious
design choices for a person skilled in the art. The Board
also considered SynQor’s objective evidence of nonobvi-
ousness in connection with rejection II and held that,
although “substantial evidence” of secondary considera-
tions existed in the record, the evidence “principally”
related to “features of the independent claims” that were
held to be anticipated in SynQor II and therefore did not
outweigh evidence of obviousness. -2288 J.A. 31–32.
Although that ruling is not consistent with the Board’s
evaluation of the same secondary consideration evidence
in the ’290’s reexamination (see § IV.A., supra), the Board
did not explain in either decision why it weighed the same
evidence differently and reached different outcomes in its
decisions for the two related patents. Regarding rejec-
tions III–IV, the Board held that a person skilled in the
art would have been motivated to combine Steigerwald
and Pressman, ruling oppositely on the same issue pre-
sented in the ’290’s reexamination. Specifically, the
Board held that it would have been obvious to insert
Pressman’s switching regulators into Steigerwald ’090’s
circuit, despite statements discouraging this combination
in the prosecution history of Steigerwald ’090.
18                               VICOR CORP.   v. SYNQOR, INC.

     SynQor requested rehearing of the Board’s decision.
On rehearing, the Board confirmed its prior holdings.
Regarding rejection I, the Board stated that Steigerwald’s
input is “always connected to the output of the secondary
winding circuit” and, therefore, that there is “continuous
power flow” through Steigerwald’s windings. Id. at 9. On
rejections III–IV, the Board more specifically identified a
motivation to combine Steigerwald and Pressman by
citing Pressman’s teaching that switching regulators
could improve the efficiency of circuit regulation. The
Board also reconsidered the objective evidence and held
that, while the evidence did “tend to somewhat support a
case of nonobviousness,” there was nevertheless strong
evidence of obviousness that outweighed such evidence.
Id. at 18. Thus, the Board appeared to arrive at different
conclusions in the ’290 and ’021’s respective reexamina-
tions as to the persuasiveness of the objective evidence
presented in both reexaminations. The Board concluded
that all disputed claims of the ’021 patent were unpatent-
able.
    Vicor and SynQor timely appealed the Board’s respec-
tive decisions. We have jurisdiction under 28 U.S.C.
§ 1295(a)(4)(A).
                       DISCUSSION
    We review decisions by the Board under the stand-
ards set forth in the Administrative Procedure Act (APA),
5 U.S.C. § 706. Pride Mobility Prods. Corp. v. Permobil,
Inc., 818 F.3d 1307, 1313 (Fed. Cir. 2016). We set aside
the Board’s actions if they are “arbitrary, capricious, an
abuse of discretion, or otherwise not in accordance with
law” or “unsupported by substantial evidence.” 5 U.S.C.
§ 706(2). The Board’s legal determinations are reviewed
de novo and its factual findings for substantial evidence.
ACCO Brands Corp. v. Fellowes, Inc., 813 F.3d 1361, 1365
(Fed. Cir. 2016). “A finding is supported by substantial
evidence if a reasonable mind might accept the evidence
VICOR CORP.   v. SYNQOR, INC.                            19

to support the finding.” K/S Himpp v. Hear–Wear Techs.,
LLC, 751 F.3d 1362, 1364 (Fed. Cir. 2014) (citation omit-
ted).
    Obviousness “is a question of law based on underlying
findings of fact.” In re Gartside, 203 F.3d 1305, 1316
(Fed. Cir. 2000) (citation omitted). The factual analysis of
an obviousness determination is framed by the factors set
out in Graham: (1) “the scope and content of the prior
art,” (2) “differences between the prior art and the claims
at issue,” (3) “the level of ordinary skill in the pertinent
art,” and (4) “secondary considerations” such as “commer-
cial success, long felt but unsolved needs,” and “failure of
others.” 383 U.S. at 17.
    Anticipation is a question of fact reviewed for sub-
stantial evidence. Eli Lilly & Co. v. Bd. of Regents of
Univ. of Wash., 334 F.3d 1264, 1267 (Fed. Cir. 2003).
              I. The ’290 Patent’s Reexamination
A. Proposed Rejections I–II: Obviousness over Steigerwald
               ’090, Cobos, and Pressman
     The Board found that a person skilled in the art
would not have been motivated to combine Steigerwald
’090 and Cobos because of operating frequency incompati-
bilities between the references’ circuits. Cobos states that
its circuit must operate at frequencies lower than 1 MHz.
Steigerwald ’090 does not explicitly recite an operating
frequency range. However, the Board relied on testimony
by SynQor’s expert, Dr. Schlecht, in finding that Stei-
gerwald ’090’s circuit would be functionally constrained to
operate at frequencies above 3.6 MHz. Dr. Schlecht’s
testimony was based in part on teachings in publications
that antedated the ’290’s priority date.
    Vicor argues Dr. Schlecht’s testimony is biased and
that substantial evidence does not support the Board’s
decision on these proposed rejections. We disagree. The
Board relied on testimony from Dr. Schlecht that refers to
20                               VICOR CORP.   v. SYNQOR, INC.

and is supported by teachings in an article and paper
published before the priority date of the ’290 patent,
which indicate that the particular circuit topology used in
Steigerwald ’090 was designed to operate at frequencies of
3.6 MHz and higher. In this instance, Dr. Schlecht’s
testimony and the references referred to therein are
substantial evidence that a skilled artisan would not have
been motivated to combine Cobos with Steigerwald ’090,
despite Dr. Schlecht’s interest in the outcome of this
litigation.
    Because Cobos is the only reference relied on in these
proposed rejections to supply the controlled rectifiers
required in all claims of the ’290 patent, 14 and in view of
the foregoing, we affirm the Board’s decision not to adopt
proposed rejections I–II.
B. Proposed Rejections III–IV: Obviousness over JP ’446,
           Steigerwald ’539, and Kassakian
    The Board affirmed the examiner’s decision to with-
draw proposed rejections III–IV based solely on SynQor’s
proffered objective evidence of nonobviousness.         The
objective evidence consisted of evidence submitted to the
jury in SynQor I, including evidence of commercial suc-
cess of infringing products, long-felt need for an improved
power architecture for large computer and telecommuni-
cations systems, failure of others to create an improved
power architecture, and praise of SynQor’s IBA solution.
The Board held that the ’290 patent’s claims covered the
same IBA design covered by the patents asserted in
SynQor I and that there was a nexus between the objec-
tive evidence and the disputed claims of the ’290 patent.
The Board and the examiner made no assessment of

     14Pressman was relied on solely for its disclosure of
switching regulators in this combination.
VICOR CORP.   v. SYNQOR, INC.                            21

Vicor’s proposed combination of JP ’446, Steigerwald ’539,
and Kassakian under the first three Graham factors.
    The Board’s decision on these proposed rejections was
erroneous and must be vacated for two reasons. First, the
Board improperly analyzed Vicor’s obviousness argu-
ments under only one of the four Graham factors when it
looked exclusively at the objective evidence, without
considering the remaining factors and the relative
strength of the factors. Second, the Board reached incon-
sistent conclusions as to the evidentiary weight to be
given to the secondary considerations evidence presented
in the respective reexaminations of the ’290 and ’021
patents, without any explanation to justify such incon-
sistency.
     The Board’s legal error is underscored by its opinion
issued on the same day in the related reexamination of
the ’021 patent. In that decision, the Board applied all
four Graham factors in the ’021’s reexamination and
stated that “[t]he Federal Circuit has determined that
only after considering the four Graham criteria together
can the decision maker make the legal determination of
whether the invention is nonobvious.” -2288 J.A. 14
(citing Panduit v. Dennison Mfg. Co., 810 F.2d 1561, 1570
(Fed. Cir. 1987)). The Supreme Court instructed that, in
performing an obviousness inquiry, “the scope and content
of the prior art are to be determined; differences between
the prior art and the claims at issue are to be ascertained;
and the level of ordinary skill in the pertinent art re-
solved. Against this background, the obviousness or
nonobviousness of the subject matter is determined.”
Graham, 383 U.S. at 17. We have interpreted this man-
date to require that “evidence relating to all four Graham
factors—including objective evidence of secondary consid-
erations—must be considered before determining
whether the claimed invention would have been obvious
to one of skill in the art at the time of invention.” Apple
Inc. v. Int’l Trade Comm’n, 725 F.3d 1356, 1365 (Fed. Cir.
22                               VICOR CORP.   v. SYNQOR, INC.

2013) (emphasis added). The Board was clearly aware of
these requirements but nevertheless chose to affirm the
examiner rather than send the issue back with instruc-
tions to consider Vicor’s obviousness arguments. This was
error.
     The Board’s decision is also erroneous because the
Board reached inconsistent conclusions regarding the
weight to be accorded the objective indicia evidence pre-
sented in both reexaminations of the SynQor Patents. In
the ’290’s reexamination, the Board found the objective
evidence to be so persuasive that it approved of the exam-
iner’s decision to withdraw rejections without analyzing
the remaining Graham factors and without considering
our holding in SynQor II that claims covering IBA’s basic
concept were anticipated by Steigerwald. In the ’021’s
reexamination, however, the Board determined that the
objective evidence principally related to features of the
claims that were found to be anticipated in SynQor II and,
therefore, found that there was no nexus between the
objective evidence and the claims of the ’021 patent. The
Board’s decisions do not evince any explanation or justifi-
cation for these inconsistent findings, given the similarity
between the claims at issue in the respective reexamina-
tions. While not every instance of an agency reaching
inconsistent outcomes in similar, related cases will neces-
sarily be erroneous, under the circumstances here, where
a panel simultaneously issues opinions on the same
technical issue between the same parties on the same
record, and reaches opposite results without explanation,
we think the best course is to vacate and remand these
findings for further consideration. See Local 814, Int’l
Bhd. of Teamsters v. N.L.R.B., 512 F.2d 564, 567 (D.C.
Cir. 1975) (remanding two decisions of the National Labor
Relations Board that were “factually similar and ostensi-
bly inconsistent” because the Board “ha[d] not explained
its reasons for reaching different results”).
VICOR CORP.   v. SYNQOR, INC.                           23

    In SynQor II, we vacated the Board’s nonobviousness
determinations for certain claims in light of our finding
that Steigerwald anticipated other claims of the ’190
patent that covered IBA’s basic arrangement. SynQor II,
603 F. App’x at 975. As already discussed above, repre-
sentative claim 20 of the ’190 patent, which we held was
anticipated in SynQor II, is substantively identical to the
claims of the SynQor Patents, with the exception of limi-
tations relating to, for example, switching regulators,
continuous power flow through transformer windings, and
input/output voltage ranges.      Moreover, SynQor has
admitted in statements to the Board that the claims of the
’290 patent cover IBA in the same way as the claims of
the ’190 patent. The parties were not given an opportuni-
ty to submit briefing on the impact of our SynQor II
opinion before the Board, because the SynQor II decision
issued after briefing had been completed in both reexami-
nations. 15   Although the obviousness arguments in
SynQor II related to different, but anticipating, prior art
references than those at issue here, the parties should be
given an opportunity on remand to present argument on
whether SynQor’s objective evidence is attributable to
IBA—as anticipated in SynQor II—or to other features in
the SynQor Patents’ claims. Our holding in SynQor II
may be particularly relevant for the proposed rejections at
issue here, given SynQor’s almost singular focus on IBA
as a general concept in its prior arguments before the
Board on the objective evidence.

   15    The parties raise arguments in their briefing in
the instant appeals as to the import of SynQor II and
whether a nexus may be found between the objective
evidence and features of the claims that were not found to
be anticipated in SynQor II. These arguments were not
raised before the Board, and we decline to consider them
in the first instance.
24                               VICOR CORP.   v. SYNQOR, INC.

    For the foregoing reasons, we vacate the Board’s deci-
sion on these proposed rejections and remand for further
proceedings consistent with this opinion. 16
     C. Proposed Rejections V–VI: Obviousness over Stei-
                   gerwald and Pressman
    In the ’290’s reexamination, the Board held that it
would not have been obvious to use Pressman’s switching
regulators for Steigerwald’s regulation stage. Yet on the
same day, the Board reached the opposite conclusion on
this issue in the ’021’s reexamination on essentially the
same record. 17 Because the Board did not provide any
reasoned explanation for the inconsistent result across
the two reexaminations, we vacate and remand the
Board’s decision on proposed rejections V–VI in the ’290’s
reexamination and rejections III–IV in the ’021’s reexam-
ination. See Local 814, 512 F.2d at 567.
    In declining to adopt proposed rejections V–VI in the
’290’s reexamination, the Board relied on disclosures in
Steigerwald and testimony by Dr. Robert Steigerwald,

     16  In SynQor I, we discussed the objective evidence
as part of the substantial evidence that supported the
jury’s nonobviousness verdict. 709 F.3d at 1377. These
observations were made on a different record with respect
to different prior art references and were made before we
found that at least one implementation of IBA was antici-
pated in SynQor II. Given these circumstances, the Board
should not give our discussion in SynQor I undue weight
on the secondary considerations issue.
    17   The parties acknowledged that, although there
were “minor differences” between the records in the
reexaminations, the Board made inconsistent holdings on
essentially the same record. See -2283 Oral Argument at
3:17–3:26, 13:54–14:18, available at http://oralarguments.
cafc.uscourts.gov/default.aspx?fl=2016-2283.mp3.
VICOR CORP.   v. SYNQOR, INC.                           25

sole inventor of the Steigerwald patents, to hold that a
skilled artisan would not have been motivated to combine
Pressman’s switching regulators with Steigerwald be-
cause Steigerwald was “principally directed to pulsed
loads.” -2283 J.A. 21–22. A “load” is a circuit component
that consumes power supplied by a DC-DC power con-
verter. A “pulsed” load is simply a load that requires
intermittent pulses of power rather than a constant level
of power. The Board adopted SynQor’s position that a
skilled artisan would not have been motivated to alter
Steigerwald to include switching regulators because a
switching regulator on Steigerwald’s pulsed load wire
would have introduced inductance on the wire and, as a
result, would have inhibited delivery of pulsed power.
    In the ’021’s reexamination, however, the Board held
that a skilled artisan would have been motivated to
incorporate Pressman’s switching regulators into Stei-
gerwald because “[t]he express teaching in Pressman of
enhanced efficiency, in [the Board’s] view, outweigh[ed]
the undesirability of additional inductance, when consid-
ered in view of the Steigerwald alternative embodiment.”
-2288 J.A. 11–12.
    We find that the direct conflict between the Board’s
fact findings in the reexaminations before us is unsup-
ported by any rational explanation in either of the Board’s
decisions. See Gartside, 203 F.3d at 1312 (citing Hyundai
Elecs. Indus. Co. v. ITC, 899 F.2d 1204, 1209 (Fed. Cir.
1990), which noted that the “touchstone” of the “arbitrary,
capricious” standard is “rationality”)). “[A]n agency’s
[fact] finding may be supported by substantial evidence,”
yet “nonetheless reflect arbitrary and capricious action.”
Bowman Transp., Inc. v. Arkansas–Best Freight Sys., Inc.,
419 U.S. 281, 284 (1974). Moreover, “this is not a case
where a more reasoned explanation than that provided by
the Board can be gleaned from the record.” Arendi
S.A.R.L. v. Apple Inc., 832 F.3d 1355, 1366 (Fed. Cir.
2016). As explained above in § I.B., our opinion today
26                               VICOR CORP.   v. SYNQOR, INC.

should not be read to suggest agency error whenever an
agency reaches inconsistent outcomes in similar, related
cases. But given the circumstances here, we think the
best course is to vacate and remand for further considera-
tion. On remand, the Board must at least provide some
reasoned basis for its opposite holdings, if it chooses to
maintain those same, opposing results.
     Vicor presents an additional basis for vacating the
Board’s decision declining to adopt Vicor’s proposed
rejections (in the ’290’s reexamination). Vicor argues that
the Board’s decision is contrary to law because the Board
failed to consider two of Vicor’s arguments raised in its
request for reexamination. The two allegedly overlooked
arguments are: (1) it would have been obvious to use
Pressman’s switching regulators exclusively on Stei-
gerwald’s non-pulsed loads because a skilled artisan
would have looked to Steigerwald for all that it teaches
and not just focus on pulsed loads, and (2) it would have
been obvious to convert all of Steigerwald’s loads into non-
pulsed loads and add switching regulators.
    While the Board may have indirectly acknowledged
these arguments in part by finding that Steigerwald was
“principally directed to pulsed loads,” we cannot conclude
with any confidence that it met its requirement to address
all grounds for proposed rejection under the APA. See
SEC v. Chenery Corp., 318 U.S. 80, 88 (1943) (“The
grounds upon which an administrative order must be
judged are those upon which the record discloses that its
action was based.”). On remand, the Board must address
Vicor’s two arguments regarding Steigerwald’s non-pulsed
loads. If the Board finds that there would have been no
motivation to combine Steigerwald and Pressman because
of what Steigerwald is principally directed to, it must
expressly say so with an adequate explanation. See
WBIP, LLC v. Kohler Co., 829 F.3d 1317, 1337 (Fed. Cir.
2016) (“Whether a skilled artisan would be motivated to
make a combination includes whether he would select
VICOR CORP.   v. SYNQOR, INC.                           27

particular references in order to combine their elements.
This is part of the fact question . . . .”).
    As discussed in § I.B., supra, the Board must recon-
sider the weight to be accorded SynQor’s proffered sec-
ondary considerations evidence in the SynQor Patents’
respective reexaminations. This reconsideration should
include analysis of whether there is a nexus between the
secondary considerations evidence and the switching
regulators at issue here for proposed rejections V–VI.
              II. The ’021 Patent’s Reexamination
    Having addressed Vicor’s appeal of the Board’s deci-
sion in the ’290’s reexamination, we next turn to SynQor’s
appeal of the Board’s decision in the ’021’s reexamination,
in which the Board affirmed all of the rejections.
       A. Rejection I: Anticipation by Steigerwald
    SynQor raises two arguments challenging the Board’s
decision that Steigerwald anticipates certain claims of the
’021 patent. First, SynQor argues that the Board improp-
erly relied on a new—and erroneous—ground of rejection
on rehearing. -2288 Open. Br. at 26 (citing -2288 J.A. 7).
Second, SynQor argues that the Board erred by “failing to
consider SynQor’s argument that Steigerwald does not
teach ‘substantially uninterrupted’ power flow in the
alternative synchronous rectifier embodiment” due to
timing of the synchronous rectifiers. Id. Both arguments
are unpersuasive, and we therefore affirm the Board’s
holding of anticipation by Steigerwald.
    First, SynQor argues that the Board erred by finding,
for the first time on rehearing as a new ground for rejec-
tion, that average current in Figure 2a of Steigerwald ’539
“showed that power was constantly flowing in the second-
ary winding circuit of the Steigerwald converters.” Id. at
27. In SynQor’s view, the Board relied on this finding to
conclude that Steigerwald ’539 discloses the “substantial-
ly uninterrupted flow of power” limitation in the claims.
28                                VICOR CORP.   v. SYNQOR, INC.

SynQor also contends that this finding is erroneous and
unsupported by substantial evidence. Id. at 35. Vicor
responds that the “thrust of the rejection” on this issue
“has not changed since the initial request for reexamina-
tion” and that the Board was merely responding to an
argument raised by SynQor for the first time in its re-
quest for rehearing. -2288 Resp. Br. at 9. In addition,
Vicor argues that the Board’s average-current finding on
rehearing was irrelevant because the Board’s initial
decision fully and independently addressed the rejection
as initially presented, and the Board did not alter its
original decision on rehearing. -2288 Oral Argument at
20:42–21:16,                  available                 at
http://oralarguments.cafc.uscourts.gov/default.aspx?fl=20
16-2288.mp3. We agree with Vicor on this latter point.
     In this case, it was not enough for SynQor to “show
the existence of error.” In re Watts, 354 F.3d 1362, 1369
(Fed. Cir. 2004). SynQor was also required to “show that
the error was in fact harmful because it affected the
decision below.” Id.; 5 U.S.C. § 706 (“[In reviewing the
Agency decision] the court shall review the whole record
or those parts of it cited by a party, and due account shall
be taken of the rule of prejudicial error.”); see also Munoz
v. Strahm Farms, Inc., 69 F.3d 501, 504 (Fed. Cir. 1995)
(“The correction of an error must yield a different result in
order for that error to have been harmful and thus preju-
dice a substantial right of a party.”); Palmer v. Hoffman,
318 U.S. 109, 116 (1943) (“He who seeks to have a judg-
ment set aside because of an erroneous ruling carries the
burden of showing that prejudice resulted.”). SynQor
failed to show prejudicial error in this instance because,
as explained below, the Board also adopted the Examin-
er’s original findings, which are supported by substantial
evidence as an independent basis to support the conclu-
sion that Steigerwald discloses substantially uninterrupt-
ed power flow through its windings. See -2288 J.A. 25.
VICOR CORP.   v. SYNQOR, INC.                           29

     Second, SynQor argues that the Board erred by failing
to consider its argument that Steigerwald lacks substan-
tially uninterrupted power flow due to switching delays of
Steigerwald’s synchronous rectifiers.       The allegedly
overlooked argument posits that, even if power flow is
uninterrupted in the uncontrolled-rectifier embodiment of
Steigerwald ’090, incorporating Steigerwald ’539’s syn-
chronous rectifiers into the circuit would create interrup-
tions in power flow due to short delays in activating
transistor gate terminals of the synchronous rectifiers.
SynQor identifies Figure 10e from Steigerwald ’539 as
depicting these short “off periods.” Vicor responds that,
“even if interruptions were to occur because of the wave-
form in Fig. 10e, the claims do not require absence of any
interruption. Rather, the claims require the duty cycle to
cause ‘substantially uninterrupted’ power flow in normal
operation.” -2288 Resp. Br. at 31 (emphasis omitted). We
agree with Vicor.
    The Board expressly acknowledged SynQor’s allegedly
overlooked argument in its opinion. See -2288 J.A. 5.
While the Board’s opinion is not crystal clear in explain-
ing the bases for its decision, the Board’s opinion suffi-
ciently addressed SynQor’s argument by adopting the
examiner’s observation that Steigerwald meets the unin-
terrupted power flow limitation because “[t]he [Stei-
gerwald] isolation stage includes two transformers that
operate in opposite phase, each at a complementary 50%
duty cycle. ‘As a consequence, the energy storage capaci-
tor Ce is always transformer coupled to the dc out-
put.’” -2288 J.A. 25 (quoting Steigerwald ’539, J.A. 626,
3:33–38). This finding is supported by the disclosures of
Steigerwald ’539 and is, therefore, supported by substan-
tial evidence. The ’021 patent expressly contemplates
interruptions in power flow like those depicted in Stei-
gerwald ’539’s Figure 10e. ’021 patent col. 4 ll. 8–11
(“[D]uring normal operation[,] the isolation stage is oper-
ated at a fixed duty cycle in which power is always flow-
30                               VICOR CORP.   v. SYNQOR, INC.

ing from input to output (except during the brief
switch transitions).” (emphasis added)).
 B. Rejection II: Obviousness over Steigerwald in View of
           Person of Ordinary Skill’s Knowledge
    The Board held that claims 23, 25, and 27–30 of the
’021 patent, which include voltage-range limitations,
would have been obvious because a skilled artisan “would
have implemented those voltages as the result of routine
design choice for a circuit for use in particular operating
environments.” -2288 J.A. 30. SynQor argues that this
decision was erroneous because Steigerwald teaches away
from implementing its circuit in computer or telecommu-
nications applications by requiring use of relatively small
capacitors and larger voltages than those recited in the
claims. Vicor counters that the Board’s decision is sup-
ported by substantial evidence in the form of expert
testimony, which averred that a person skilled in the art
would have understood Steigerwald’s circuit to be imple-
mentable in computer and telecommunications applica-
tions using the claimed voltages. We agree with Vicor
that the Board’s decision on these claims is supported by
the substantial evidence cited by Vicor. See -2288 J.A. 30
(Board discussing expert testimony). In addition, regard-
ing the secondary considerations evidence that SynQor
presented in connection with these claims, the Board’s
finding that such evidence was “principally” directed to
“features of the [anticipated] independent claims,” and is
therefore of lesser probative value, is supported by sub-
stantial evidence. See, e.g., J.A. 13–18, 30–32 (Board
discussing secondary considerations evidence). Therefore,
we affirm the Board’s decision on rejection II.
     C. Rejection III: Obviousness over Steigerwald and
                          Pressman
    For the reasons already discussed, we vacate and re-
mand the Board’s decision on this rejection for reconsid-
eration of whether it would have been obvious to
VICOR CORP.   v. SYNQOR, INC.                           31

incorporate Pressman’s switching regulators into Stei-
gerwald’s circuit. As discussed in § I.B., supra, the Board
must reconsider the weight to be accorded SynQor’s
proffered secondary considerations evidence in the
SynQor Patents’ respective reexaminations. This recon-
sideration should include analysis of whether there is a
nexus between the secondary considerations evidence and
the switching regulators at issue here for rejection III.
D. Rejection IV: Obviousness over Steigerwald, Pressman,
                  and Admitted Prior Art
    Rejection IV addressed claim 50 of the ’021 patent,
which combines the switching regulator limitation in
claim 49 with voltage range limitations addressed above
with respect to rejection II. For the reasons above, we
vacate and remand the Board’s decision on this rejection
for reconsideration of whether it would have been obvious
to incorporate Pressman’s switching regulators into
Steigerwald’s circuit. The Board’s findings related to the
voltage range limitations of claim 50 are supported by
substantial evidence, for the reasons given above in
connection with rejection II. Again, as noted above, we
vacate and remand the Board’s secondary considerations
decision for this rejection. See § I.B., supra.
                         CONCLUSION
    The decisions of the Board are affirmed in part, vacat-
ed in part, and remanded for further proceedings con-
sistent with this opinion.
  AFFIRMED-IN-PART, VACATED-IN-PART, AND
                REMANDED
                                COSTS
   No costs.