Presidio Components, Inc. v. American Technical Ceramics Corp. ( 2017 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    PRESIDIO COMPONENTS, INC.,
    Plaintiff-Cross-Appellant
    v.
    AMERICAN TECHNICAL CERAMICS CORP.,
    Defendant-Appellant
    ______________________
    2016-2607, 2016-2650
    ______________________
    Appeals from the United States District Court for the
    Southern District of California in No. 3:14-cv-02061-H-
    BGS, Judge Marilyn L. Huff.
    ______________________
    Decided: November 21, 2017
    ______________________
    BRETT A. SCHATZ, Wood, Herron & Evans, LLP, Cin-
    cinnati, OH, argued for plaintiff-cross-appellant. Also
    represented by GREGORY F. AHRENS.
    RONALD E. CAHILL, Nutter McClennen & Fish LLP,
    Boston, MA, argued for defendant-appellant. Also repre-
    sented by HEATHER BURNADETTE REPICKY; PETER F.
    SNELL, Mintz, Levin, Cohn, Ferris, Glovsky and Popeo,
    P.C., New York, NY.
    ______________________
    2          PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    Before DYK, MOORE, and TARANTO, Circuit Judges.
    DYK, Circuit Judge.
    Presidio filed suit against American Technical Ceram-
    ics Corp. (“ATC”) for patent infringement in the District
    Court for the Southern District of California. After sepa-
    rate jury and bench trials, the district court held the
    asserted claims were infringed and not invalid, and
    granted a permanent injunction. The district court limited
    damages due to intervening rights.
    We affirm the district court’s holdings that the claims
    are not indefinite and that ATC is entitled to absolute
    intervening rights because a substantive amendment was
    made during reexamination. We conclude that the evi-
    dence does not support an award of lost profits and,
    therefore, reverse the award of lost profits and remand for
    determination of a reasonable royalty. We conclude that
    the district court did not abuse its discretion in declining
    to award enhanced damages. We vacate the permanent
    injunction, and remand for further proceedings with
    respect to the injunction.
    BACKGROUND
    Presidio’s suit against ATC, filed on September 2,
    2014, alleged infringement of 
    U.S. Patent No. 6,816,356
    (“the ’356 patent”). The ’356 patent claims a multilayer
    capacitor design and teaches a multilayer integrated
    network of capacitors electrically connected in series and
    in parallel.
    A capacitor is a passive electrical component that
    stores and releases energy. Generally, a capacitor com-
    prises two parallel metal plates separated by a non-
    conductive material, known as a dielectric. When a capac-
    itor is connected to a power source, electricity passes
    through the metal plates, but not through the dielectric
    material. This causes a positive charge to accumulate on
    one plate and a negative charge to accumulate on the
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS        3
    other plate. The capacitor will then release the stored
    energy when the two plates are connected to a conductive
    path that closes the circuit. The amount of energy that a
    capacitor can store is called its “capacitance.”
    Multiple capacitors can be combined to form a multi-
    layer capacitor. The claimed multilayer capacitor creates
    capacitance in the dielectric material between the parallel
    plate combinations. Moreover, when the electrodes of a
    multilayer capacitor are positioned in an edge-to-edge
    relationship, they form “fringe-effect” capacitance be-
    tween the external contacts. “Fringe-effect” capacitance is
    the energy stored in between external contacts of the
    multilayer capacitor.
    While the district court infringement suit was pend-
    ing, in 2015, ATC sought an ex parte reexamination of the
    claims of the ’356 patent in light of new prior art. The
    examiner rejected the claims as anticipated and obvious.
    Presidio amended the claims. The Patent and Trademark
    Office issued a reexamination certificate for the ’356
    patent. 1 Amended claim 1 of the ’356 patent, the only
    independent claim asserted by Presidio in this action, is
    as follows, with the language added during reexamination
    underscored:
    1. A capacitor comprising:
    a substantially monolithic dielectric body;
    a conductive first plate disposed within
    the dielectric body;
    1   The PTO previously issued a reexamination certificate
    for the ’356 patent on September 13, 2011. This reexami-
    nation certificate did not alter any of the claims at issue
    in this case.
    4          PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    a conductive second plate disposed within
    the dielectric body and forming a capacitor
    with the first plate;
    a conductive first contact disposed exter-
    nally on the dielectric body and electrical-
    ly connected to the first plate; and
    a conductive second contact disposed ex-
    ternally on the dielectric body and electri-
    cally connected to the second plate, and
    the second contact being located sufficient-
    ly close to the first contact in an edge to
    edge relationship in such proximity as to
    form a first fringe-effect capacitance with
    the first contact that is capable of being
    determined by measurement in terms of a
    standard unit.
    
    U.S. Patent No. 6,816,356 C2
    , col. 1, ll. 23–36 (Reex-
    amination Certificate filed Dec. 8, 2015).
    On December 22, 2015, Presidio amended its district
    court complaint, alleging infringement of the ’356 patent
    claims 1, 3, 5, 16, 18, and 19 as amended by the reexami-
    nation certificate. Presidio alleged that ATC’s 550 line of
    capacitors infringed the asserted claims.
    ATC defended, as is relevant for present purposes,
    that the claims were indefinite; that the reexamination
    amendment entitled it to intervening rights, limiting
    damages; and that Presidio was not entitled to lost profits
    or enhanced damages. The district court granted ATC’s
    motion for summary judgment on the affirmative defense
    of absolute intervening rights. The district court then held
    a jury trial. The jury returned a verdict finding direct
    infringement and induced infringement of claims 1, 3, 5,
    16, 18, and 19 of the ’356 patent by all of the accused
    products—ATC’s 550 line of capacitors. In addition, the
    jury found that Presidio had proven by clear and convinc-
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS          5
    ing evidence that ATC’s infringement of the asserted
    claims was willful. The jury awarded Presidio $2,166,654
    in lost profit damages. It did not reach Presidio’s claim for
    a reasonable royalty. The jury also issued an advisory
    verdict as to indefiniteness, finding that ATC failed to
    prove by clear and convincing evidence that claim 1 of the
    ’356 patent is indefinite. 2
    The district court thereafter rejected ATC’s contention
    that the asserted claims of the ‘356 patent are invalid due
    to indefiniteness and denied ATC’s motion that Presidio
    had failed as a matter of law to prove lost profits. The
    district court also denied Presidio’s motion for enhanced
    damages, determining that enhanced damages were not
    warranted despite a jury finding of willful infringement.
    The district court then entered a permanent injunction
    against ATC.
    ATC appealed, challenging the district court’s deter-
    mination that the claims were not indefinite, the award of
    lost profits, and the award of a permanent injunction.
    Presidio cross-appealed, challenging the district court’s
    determination as to absolute intervening rights and the
    denial of enhanced damages. We have jurisdiction under
    
    28 U.S.C. § 1295
    (a)(1).
    On October 21, 2016, we granted a partial stay of the
    injunction until March 17, 2017 with respect to ATC’s
    customers that purchased infringing capacitors before
    June 17, 2016.
    2   Claims 3, 5, 16, 18, and 19 of the ’356 patent all
    depend from claim 1. Thus, all claims in this suit contain
    the limitation from claim 1 at issue.
    6           PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    DISCUSSION
    I
    We first address whether the claims are indefinite. 
    35 U.S.C. § 112
     provides that “[t]he specification shall con-
    clude with one or more claims particularly pointing out
    and distinctly claiming the subject matter which the
    applicant regards as his invention.” Indefiniteness is a
    question of law that this court reviews de novo. Teva
    Pharm. USA, Inc. v. Sandoz, Inc., 
    789 F.3d 1335
    , 1341
    (Fed. Cir. 2015). Underlying factual findings are reviewed
    for clear error. UltimatePointer, LLC v. Nintendo Co., 
    816 F.3d 816
    , 826 (Fed. Cir. 2016). A patent is indefinite “if its
    claims, read in light of the specification delineating the
    patent, and the prosecution history, fail to inform, with
    reasonable certainty, those skilled in the art about the
    scope of the invention.” Nautilus, Inc v. Biosig Instru-
    ments, Inc., 
    134 S. Ct. 2120
    , 2124 (2014). The definiteness
    requirement “mandates clarity, while recognizing that
    absolute precision is unattainable.” 
    Id. at 2129
    .
    As noted earlier, the claims here cover multilayer ca-
    pacitors with a fringe-effect capacitance between external
    contacts that is “capable of being determined by meas-
    urement in terms of a standard unit.” 
    U.S. Patent No. 6,816,356 C2
    , col. 1, ll. 35–36 (Reexamination Certificate
    filed Dec. 8, 2015).
    Here, the patent discloses a method of measuring ca-
    pacitance called insertion loss testing. The patent specifi-
    cation references insertion loss testing as a method to
    measure the performance of capacitors. Figures 21A and
    21B display insertion loss diagrams, which identify inser-
    tion loss testing as a method that may be used to measure
    performance of capacitors. ’356 patent, col. 6, ll. 10–15,
    col. 7, ll. 3–18. Moreover, in the prosecution history dur-
    ing the reexamination, Presidio amended the claims to
    require fringe effect capacitance capable of being deter-
    mined “by measurement” and explained that the effects of
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS         7
    a capacitance according to the invention “can be shown by
    measurement, such as is done in the measurements of
    insertion loss referenced in the patent in Figs. 21A and
    21B.” J.A. 2654, 2656. The method of insertion loss test-
    ing was well-known in the art, and there is no dispute
    that insertion loss testing can measure the overall per-
    formance of a capacitor. Indeed, ATC uses insertion loss
    testing itself to measure the performance of capacitors
    when comparing its products to Presidio’s products for
    purposes of determining whether Presidio lost sales to
    ATC. See infra Part III.
    Insertion loss measures how much of a signal is lost
    when a capacitor is inserted into a circuit. To determine
    insertion loss, a network analyzer measures the ratio of
    the input power to the output power of the capacitor in a
    circuit, which indicates the efficiency with which the
    signal passes through the capacitor in the circuit. The
    measurement unit for insertion loss is decibels, and this
    measurement is a function of all of the capacitances,
    resistances, and inductances within the capacitor. Thus,
    the insertion loss value correlates to the overall capaci-
    tance of the capacitor. Although industry standards for
    insertion loss testing had not been published at the time
    the patent was filed, Presidio’s expert, Dr. Huebner,
    testified that insertion loss testing had been “well known
    for many decades” and that a person of ordinary skill
    could use insertion loss measurements to measure capaci-
    tance in terms of Farads, the standard unit of measure-
    ment for capacitance. J.A. 1513, 1376-80.
    While it was established that insertion loss testing
    could be used to measure overall performance of capaci-
    tors, it was not well known as a method to measure the
    comparative contributions from different capacitances
    within the multilayer capacitor. Nor does the patent
    specification describe how to apply the insertion loss
    method to determine the portion of the overall capaci-
    tance that is attributable to the fringe-effect capacitance.
    8          PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    However, at trial, Presidio presented expert testimony
    by Dr. Huebner that a person of skill in the art would
    know how to measure fringe-effect capacitance by using
    insertion loss measurements to measure the overall
    capacitance, by then removing the dielectric material
    between the multilayer plates, and by then taking inser-
    tion loss measurements to determine the remaining
    capacitance. Without the dielectric material, the remain-
    ing capacitance would necessarily be attributable to the
    fringe-effect capacitance. Thus, Dr. Huebner testified that
    a person skilled in the art could measure the impact of
    fringe-effect capacitance on performance of the capacitor.
    He also testified that a person skilled in the art would
    then be able to determine the capacitance in terms of the
    standard unit of Farads.
    Under our post-Nautilus cases, a claim is not indefi-
    nite if a person of skill in the art would know how to
    utilize a standard measurement method, such as insertion
    loss, to make the necessary measurement. A patent need
    not explicitly include information that is already well
    known in the art. Nautilus, 
    134 S. Ct. at 2127
    ; see also
    Dow Chem. Co. v. Nova Chem. Corp., 
    809 F.3d 1223
    , 1225
    (Fed. Cir. 2015) (Moore, J., concurring in the denial of the
    petition for rehearing en banc) (citing Wellman, Inc. v.
    Eastman Chem. Co., 
    642 F.3d 1355
    , 1367 (Fed. Cir.
    2011)). “[I]f a skilled person would choose an established
    method of measurement, that may be sufficient to defeat
    a claim of indefiniteness, even if that method is not set
    forth in haec verba in the patent itself.” Dow, 809 F.3d at
    1224 (Prost, C.J., Dyk & Wallach, JJ., concurring in the
    denial of the petition for rehearing en banc). For example,
    in Ethicon Endo-Surgery, Inc. v. Covidien, Inc., 
    796 F.3d 1312
    , 1316 (Fed. Cir. 2015), claims covered surgical
    shears for cutting and sealing blood vessels that required
    a clamping pressure within a specified range. The specifi-
    cation provided guidance about how to measure the
    clamping pressure, even though there was no industry
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS         9
    standard measurement method and the details of the
    method utilized were not disclosed in the specification. 
    Id.
    at 1317–19. Based on the guidance in the specification, we
    concluded the disclosure was sufficient to inform skilled
    artisans as to how clamping pressure should be meas-
    ured. 
    Id.
     And this is not a situation similar to Teva
    Pharmaceuticals USA, Inc. v. Sandoz, Inc., 
    789 F.3d 1335
    (Fed. Cir. 2015) and Dow Chemical Co. v. Nova Chemicals
    Corp., 
    803 F.3d 620
     (Fed. Cir. 2015), in which the chal-
    lenger has shown that there were competing existing
    methodologies that reached different results, and the
    patent failed to describe which of the multiple methods to
    use.
    Nonetheless, ATC argues that Dr. Huebner’s method-
    ology is not an established methodology because insertion
    loss testing had not previously been applied to measure
    fringe-effect capacitance, the patent itself provided no
    guidance as to how to make the measurement, and Dr.
    Huebner made subjective judgments in developing the
    test methodology for that purpose. In other words, ATC
    contends that Dr. Huebner developed a new test method-
    ology rather than using an established test methodology
    or one for which the patent provided necessary guidance,
    and that the claims are therefore indefinite.
    Even assuming that ATC is correct that an entirely
    new method could in some circumstances render the
    claims indefinite, this is not such a situation. Here, as we
    earlier noted, the insertion loss testing method was well
    established and referenced in the patent. Although the
    specific steps performed by Dr. Huebner had not been
    published in any industry publications or peer-reviewed
    articles, the general approach of making modifications to
    a capacitor to isolate the impact of discrete capacitances
    was within the knowledge of someone skilled in the art.
    Based on this record, the district court could properly
    conclude that such measurement was within the skill of a
    skilled artisan based on an established method.
    10         PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    Here, the claims do not require that fringe-effect ca-
    pacitance exist at any particular level; they only require
    that it be capable of measurement in terms of a standard
    unit. To be sure, even where the claims require a particu-
    lar test result, there may be (and often are) disputes
    between the parties as to the proper application of the
    test methodology in the circumstances of an individual
    case. But those disputes are disputes about whether there
    is infringement, not disputes about whether the patent
    claims are indefinite. Here, the general approach was
    sufficiently well established in the art and referenced in
    the patent to render the claims not indefinite. The claims
    do not rely on the “unpredictable vagaries of any one
    person’s opinion.” Interval Licensing LLC v. AOL, Inc.,
    
    766 F.3d 1364
    , 1371 (Fed. Cir. 2014) (quoting Datamize,
    LLC v. Plumtree Software, Inc., 
    417 F.3d 1342
    , 1350 (Fed.
    Cir. 2003)). We affirm the district court’s entry of judg-
    ment rejecting ATC’s indefiniteness challenge.
    II
    Next, we address the issue of intervening rights. Pre-
    sidio cross-appeals the district court’s grant of summary
    judgment of absolute intervening rights to ATC, which
    barred damages for the period before December 8, 2015,
    the date that the reexamination certificate issued. 3
    An owner of a patent that survives reexamination is
    not entitled to infringement damages for the time period
    between the date of issuance of the original claims and
    the date of issuance of the reexamined claims if the origi-
    nal and amended claims are not “substantially identical.”
    
    35 U.S.C. §§ 252
    , 307(b). In other words, if an amendment
    during reexamination makes a substantive change to an
    original claim, the patentee is only entitled to infringe-
    3   The district court denied ATC’s motion for equitable
    intervening rights, which has not been appealed.
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS         11
    ment damages for the changed claim for the period follow-
    ing issuance of the reexamination certificate. R+L Carri-
    ers, Inc. v. Qualcomm, Inc., 
    801 F.3d 1346
    , 1349 (Fed. Cir.
    2015); Bloom Eng’g Co. v. N. Am. Mfg. Co., 
    129 F.3d 1247
    ,
    1250 (Fed. Cir. 1997). The district court’s assessment of
    the scope of the original and reexamined claims is re-
    viewed de novo, and any subsidiary factual findings are
    reviewed for clear error. R+L Carriers, 801 F.3d at 1349–
    50.
    Presidio amended claims of the ’356 patent during an
    ex parte reexamination. As noted earlier, Presidio added
    the following underlined language to claim 1:
    the second contact being located sufficiently close
    to the first contact in an edge to edge relationship
    in such proximity as to form a first fringe-effect
    capacitance with the first contact that is capable
    of being determined by measurement in terms of a
    standard unit.
    The district court found that these amendments sub-
    stantially changed the claim scope and, therefore, ATC
    was entitled to the defense of absolute intervening rights.
    In making this determination, the district court compared
    the scope of the original claims as construed by the dis-
    trict court in a prior lawsuit between the parties, Presidio
    I, with the interpretation of the claims as amended in the
    reexamination. Presidio Components, Inc. v. Am. Tech.
    Ceramics Corp., 
    723 F. Supp. 2d 1284
     (S.D. Cal. 2010).
    Presidio argues that the scope of its claims did not
    change during reexamination because its stated goal in
    amending the claims was to adopt the district court’s
    construction in Presidio I. During reexamination, Presidio
    stated it was making the amendment “to incorporate and
    make explicit the interpretation of the independent claims
    that was established in [the Presidio I] litigation.” J.A.
    128. However, the patentee’s intent in making the
    amendment is not determinative or controlling in deter-
    12         PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    mining claim scope. Slimfold Mfg. Co. v. Kinkead Indus.,
    Inc., 
    810 F.2d 1113
    , 1116 (Fed. Cir. 1987). As we have
    explained, “[u]nder the statute and our prior case law, it
    is irrelevant why an amended claim is narrowed during
    reexamination, or even whether the patentee intended to
    narrow the claim in a particular way.” R+L Carriers, 801
    F.3d at 1350 (emphasis in original).
    Instead, the relevant inquiry is whether the scope of
    the amended claims is actually identical to the scope of
    the original claims based on normal claim construction
    analysis, articulated in our en banc Phillips decision. See
    Phillips v. AWH Corp., 
    415 F.3d 1303
     (Fed. Cir. 2005) (en
    banc). To determine whether an amended claim is nar-
    rower in scope, “we determine whether there is any prod-
    uct or process that would infringe the original claim, but
    not infringe the amended claim.” R+L Carriers, 801 F.3d
    at 1350. Typically, we need to determine de novo the
    scope of the original and amended claims. Both parties
    here appear to agree that the scope of the original claims
    is determined by the construction of the claims in Presidio
    I, apparently as a matter of collateral estoppel. See Hy-
    dranautics v. FilmTec Corp., 
    204 F.3d 880
    , 885 (9th Cir.
    2000) (explaining that collateral estoppel applies when an
    issue is identical to one necessarily decided in a previous
    proceeding, the first proceeding ended in a final judgment
    on the merits, and the party against whom collateral
    estoppel is asserted was a party in the first proceeding);
    see also Aspex Eyewear, Inc. v. Zenni Optical Inc., 
    713 F.3d 1377
    , 1380 (Fed. Cir. 2013) (explaining that the
    Federal Circuit applies the law of the circuit in which the
    district court sits for collateral estoppel). Thus, necessary
    to a determination of the scope of the original claims is an
    understanding of the district court’s claim construction in
    Presidio I.
    Presidio I was an infringement suit against ATC for
    the ’356 patent, filed on February 21, 2008. In Presidio I,
    Chief Judge Gonzalez construed the claims to require
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS         13
    fringe-effect capacitance “that is capable of being deter-
    mined in terms of a standard unit.” J.A. 5243. In this
    respect, the original and amended claims are the same, as
    both require fringe-effect capacitance that is capable of
    being determined in terms of a standard unit. But in
    other respects, the Presidio I construction and the amend-
    ed claims are materially different. This is so because
    under the claim construction of the original claims, fringe-
    effect capacitance could be determined by theoretical
    calculations that are insufficient under the amended
    claims.
    During the Presidio I trial, Dr. Huebner’s testimony
    that ATC’s products infringed used a purely theoretical
    calculation of fringe-effect capacitance. Dr. Huebner took
    measurements of dimensions and used a formula,
    C=kA/d, 4 to determine capacitance rather than measuring
    capacitance with actual instruments, as done in insertion
    loss testing. Chief Judge Gonzalez affirmed the jury
    finding of infringement based on this purely theoretical
    measurement, noting that Dr. Huebner:
    measured a determinable fringe-effect capacitance
    in the 545L capacitor by using the C=kA/d formu-
    la and inputting the actual thickness of the exter-
    nal contact, the actual separation distance, and a
    lower and upper boundary for what the dielectric
    constant might be. Accordingly, there was suffi-
    cient evidence for the jury to credit Dr. Huebner’s
    opinion and to find that the 545L capacitor had a
    ‘fringe-effect capacitance’ between the external
    contacts.
    4   In the formula C=kA/d, C is the capacitance in farads,
    k is the dielectric constant of the insulating material
    between the plates, A is the area of each of the opposed
    plates in square meters, and d is the separation distance
    between the plates.
    14         PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    J.A. 5303. Therefore, the district court concluded that the
    scope of the original claims included fringe-effect capaci-
    tance measured through purely theoretical measure-
    ments. 5
    The amended claims have a different scope. During
    the reexamination, the examiner rejected the original
    claims in light of a prior art reference that disclosed a
    capacitor arrangement where the fringe-effect capacitance
    of the arrangement could be determined using C=kA/d—
    the same theoretical calculation method used by Presid-
    io’s expert in Presidio I to opine on infringement. Presidio
    then amended the claims to overcome this rejection. The
    amendment added the words “by measurement.” When
    Presidio submitted the proposed amendments, it stated
    that the amended claim language excludes determina-
    tions of fringe-effect capacitance that “rel[y] entirely upon
    theoretical calculation” and argued that the rejections
    should be withdrawn because the prior art disclosed only
    an arrangement where fringe-effect capacitance could be
    determined “by way of theoretical computations” and not
    actual measurement. J.A. 128, 137. The patentee ex-
    plained that “determinable” includes “only what is practi-
    cally measurable, not merely what is theoretical or
    simulated.” J.A. 2659. Based on this explanation, the
    amended claims were allowed. Whether viewed as a
    disclaimer or as evidence relevant to the proper claim
    construction, it is clear that the amended claims exclude
    5   Presidio repeatedly and inaccurately states that Chief
    Judge Gonzalez held that the original claims did not
    include “theoretically calculated fringe-effect capaci-
    tance.” Presidio Br. 29, 37, 66, 70, 72; Presidio Reply Br.
    1, 3, 7, 12. In fact, Chief Judge Gonzalez only held that
    the claims exclude fringe-effect capacitance that is merely
    “negligible.” J.A. 5334.
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS         15
    capacitors with fringe-effect capacitance that could be
    determined purely through theoretical calculation.
    Therefore, there was a substantive change in claim
    scope. Under the scope of the original claims, theoretical
    calculations are sufficient to satisfy the claim limitations.
    Under the amendment claims, they are not. Based on this
    substantive change in claim scope, the district court
    properly granted the affirmative defense of absolute
    intervening rights.
    III
    The third issue is whether the district court correctly
    awarded lost profits. The district court held that the jury
    verdict awarding lost profits was supported by substantial
    evidence and denied judgment as a matter of law. The
    question is whether Presidio established its right to
    recover lost profits for its sales of the BB capacitors,
    which Presidio claimed were adversely affected by the
    sale of ATC’s infringing 550 line of capacitors.
    To recover lost profits, the patentee bears the burden
    of proof to show a “reasonable probability that, ‘but for’
    infringement, it would have made the sales that were
    made by the infringer.” Crystal Seminconductor Corp. v.
    TriTech Microelecs. Int’l, Inc., 
    246 F.3d 1336
    , 1353 (Fed.
    Cir. 2001); BIC Leisure Prods, Inc. v. Windsurfing, Int’l,
    Inc., 
    1 F.3d 1214
    , 1218 (Fed. Cir. 1993). “But-for” causa-
    tion can be proven using the test given in Panduit Corp. v.
    Stahlin Bros. Fibre Works, Inc., 
    575 F.2d 1156
     (6th Cir.
    1978). See Versata Software, Inc. v. SAP Am., Inc., 
    717 F.3d 1255
    , 1264 (Fed. Cir. 2013). The four-factor Panduit
    test requires the patentee to show: (1) demand for the
    patented product; (2) an absence of acceptable, non-
    infringing substitutes; (3) manufacturing and marketing
    capability to exploit the demand; and (4) the amount of
    profit that would have been made. Panduit, 575 F.2d at
    1156. Presidio did not and does not seek to establish an
    16         PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    entitlement to lost profits other than through the Panduit
    framework.
    We review the denial of judgment as a matter of law
    de novo, and we uphold the jury verdict if supported by
    substantial evidence. Callicrate v. Wadsworth Mfg., Inc.,
    
    427 F.3d 1361
    , 1366 (Fed. Cir. 2005). A patentee can
    recover lost profits even if its product does not practice
    the claimed invention, where the product directly com-
    petes with the infringing device. Presidio Components v.
    Am. Tech. Ceramics, 
    702 F.3d 1351
    , 1360 (Fed. Cir. 2012).
    Although the BB capacitor does not practice the ’356
    patent, Presidio could still recover lost profits because the
    BB capacitor competes directly with the infringing 550
    capacitors.
    ATC argues that the district court erred by finding
    that substantial evidence supported that Presidio had
    satisfied the second prong of Panduit analysis—the
    absence of an acceptable, non-infringing alternative. To
    prove the absence of acceptable, non-infringing alterna-
    tives, the patentee may prove either that the potential
    alternative was not acceptable to potential customers or
    was not available at the time. Grain-Processing Corp. v.
    Am. Maize-Prod. Co., 
    185 F.3d 1341
    , 1353–55 (Fed. Cir.
    1999).
    At the time of infringement, ATC sold two types of ca-
    pacitors: the 550 series capacitors, which were found to
    infringe, and the 560L capacitor, which was never accused
    of infringement. The district court found that sufficient
    evidence supported the jury’s finding that the 560L capac-
    itor was not an acceptable and available substitute.
    As to the “acceptable substitute” question, the district
    court stated that “ATC’s own witness testified that the
    560 capacitors are not as good as the 550 capacitors,” and
    concluded that “the 560L [capacitor] was not an accepta-
    ble, noninfringing alternative.” J.A. 82. On appeal, Presid-
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS         17
    io argues that “the 560L product did not perform as well
    as the infringing 550 capacitor.” Presidio Br. 56-57.
    The district court’s analysis and Presidio’s argument
    were flawed. The correct inquiry under Panduit is wheth-
    er a non-infringing alternative would be acceptable com-
    pared to the patent owner’s product, not whether it is a
    substitute for the infringing product. “The ‘but for’ inquiry
    therefore requires a reconstruction of the market, as it
    would have developed absent the infringing product, to
    determine what [sales] the patentee ‘would . . . have
    made.’” Grain Processing, 
    185 F.3d at 1350
    . The district
    court erred by relying on evidence about sales of the 560L
    capacitor in competition with the currently infringing
    product, rather than comparing the 560L capacitor to
    Presidio’s BB capacitor in a hypothetical market without
    the infringing 550 capacitor. There was not substantial
    evidence in the record upon which a jury could conclude
    that the 560L was not an acceptable, noninfringing alter-
    native for Presidio’s BB capacitors. Undisputed evidence
    showed that the 560L capacitor was less expensive than
    Presidio’s BB capacitor and also had lower insertion loss
    for at least some frequencies, which indicates better
    performance.
    On the question of availability, the district court de-
    termined that sufficient evidence supported the finding
    that the 560L capacitor was not an available substitute
    because unlike the infringing 550 capacitors, ATC sold
    the 560L capacitor only to a single customer and did not
    list it on its website. An alternative does not need to be on
    the market to be available. Grain Processing, 
    185 F.3d at 1356
    . But here, the alternative was on the market. The
    undisputed evidence shows ATC sold 88,000 560L capaci-
    tors to the customer. The fact that ATC only sold the 560L
    capacitor to a single customer does not establish that it
    was unavailable. Moreover, the fact that the 560L capaci-
    tor was not widely advertised when sold in a market with
    the 550 capacitor does not show a lack of availability. In a
    18          PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    hypothetical market including the 550 capacitors, ATC
    may have chosen not to advertise the 560L capacitor.
    However,
    [w]ithout the infringing product, a rational would-
    be infringer is likely to offer an acceptable, nonin-
    fringing alternative, if available, to compete with
    the patent owner rather than leave the market al-
    together. The competitor in the “but for” market-
    place is hardly likely to surrender its complete
    market share when faced with a patent, if it can
    compete in some other lawful manner.
    
    Id. at 1351
    . The patentee failed to establish the 560L
    capacitor was not an available substitute.
    In summary, Presidio failed to provide evidence that
    the 560L capacitor was either not an acceptable or availa-
    ble substitute to Presidio’s BB capacitor. We reverse the
    denial of judgment as a matter of law. The jury’s award of
    lost profits is set aside; Presidio is only entitled to receive
    a reasonable royalty award. Because the jury instructions
    and verdict form only directed the jury to consider a
    reasonable royalty award if Presidio had not proven it
    was entitled to lost profits, the jury did not return a
    finding about a reasonable royalty rate. Under these
    circumstances, a new trial is needed to determine the
    reasonable royalty award. 6
    IV
    Next, we address the issue of enhanced damages. The
    jury found that ATC willfully infringed the ’356 patent,
    and the district court denied judgment as a matter of law
    of no willful infringement. Despite the jury finding of
    6   It may be that the parties agree that 25 cents per unit
    is the appropriate reasonable royalty rate, rendering a
    new trial unnecessary. J.A. 1094, 1116, 1477–78.
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS          19
    willfulness, the district court declined to award enhanced
    damages. We review the determination not to award
    enhanced damages for abuse of discretion. WBIP, LLC v.
    Kohler, Co., 
    829 F.3d 1317
    , 1339 (Fed. Cir. 2016) (citing
    Halo Elecs., Inc. v. Pulse Elecs., Inc., 
    136 S. Ct. 1923
    , 1934
    (2016)).
    In patent infringement cases, district courts have dis-
    cretion to “increase damages up to three times the
    amount found or assessed.” 
    35 U.S.C. § 284
    ; Halo, 136 S.
    Ct. at 1931. Enhanced damages are generally only appro-
    priate in egregious cases of misconduct, such as willful,
    wanton, or malicious behavior. Halo, 136 S. Ct. at 1932.
    But an award of enhanced damages does not necessarily
    flow from a willfulness finding. Id.; WBIP, 829 F.3d at
    1341 n.13. Discretion remains with the court to determine
    whether the conduct is sufficiently egregious to warrant
    enhanced damages. WBIP, 829 F.3d at 1341 n.13. In
    determining whether enhanced damages are appropriate,
    courts should consider the overall circumstances of the
    case. Halo, 136 S. Ct. at 1933.
    The district court here appropriately analyzed ATC’s
    culpability only during the period beginning when the
    reexamination certificate issued on December 8, 2015.
    The district court noted that at that point, ATC and
    Presidio were already involved in the present litigation,
    and ATC had been selling the 550 capacitors for almost
    six years without a finding of infringement. At that point,
    ATC had received the district court’s claim construction
    order and developed defense theories. Additionally, ATC
    had just succeeded in causing Presidio to narrow the
    scope of its claims during reexamination proceedings
    instituted by ATC. The district court further noted that
    ATC’s invalidity defense at trial was not meritless,
    though ultimately rejected by the jury. Therefore, the
    district court concluded that the present case was a
    “garden-variety” hard-fought patent case, rather than an
    20         PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    egregious case of misconduct, and declined to award
    enhanced damages. J.A. 98-99.
    Presidio argues that the district court erred as a mat-
    ter of law by failing to explicitly address each of the Read
    factors set forth in our decision in Read as relevant to an
    award of enhanced damages. See Read Corp. v. Portec,
    Inc., 
    970 F.2d 816
     (Fed. Cir. 1992), abrogated in part on
    other grounds by Markman v. Westview Instruments, Inc.,
    
    116 S. Ct. 1384
     (1996). However, the district court is not
    required to discuss the Read factors. When the Supreme
    Court articulated the current controlling test for decisions
    to award enhanced damages, it did not require the Read
    factors as part of the analysis. Halo, 136 S. Ct. at 1935;
    see Georgetown Rail Equip. v. Holland L.P., 
    867 F.3d 1229
    , 1244 (Fed. Cir. 2017) (describing the Read factors
    as “non-exclusive”). 7 The Halo test merely requires the
    district court to consider the particular circumstances of
    the case to determine whether it is egregious. Here, the
    district court considered the particular circumstances of
    the case and determined the situation was not sufficiently
    egregious to warrant enhanced damages. The district
    court did not abuse its discretion in declining to award
    enhanced damages.
    V
    Lastly, the district court issued a permanent injunc-
    tion, which enjoined ATC from selling any 550 capacitors.
    We review the district court’s grant of an injunction for
    abuse of discretion. eBay Inc. v. MercExchange, LLC, 547
    7  Moreover, even before the Halo decision, explicit
    discussion of the Read factors was not mandatory. See,
    e.g., Metabolite Labs., Inc. v. Lab. Corp. of Am. Holdings,
    
    370 F.3d 1354
    , 1371 (Fed. Cir. 2004) (affirming a district
    court award of enhanced damages where the district court
    did not discuss the Read factors for enhanced damages).
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS        
    21 U.S. 388
    , 391 (2006). A district court abuses its discretion
    when it makes “a clear error of judgment in weighing
    relevant factors or exercise[s] its discretion based upon an
    error of law or clearly erroneous factual findings.” In-
    nogenetics, N.V. v. Abbott Labs., 
    512 F.3d 1363
    , 1379
    (Fed. Cir. 2008).
    A permanent injunction may be entered against an in-
    fringer where the patentee can prove: (1) it has suffered
    an irreparable injury; (2) legal remedies, such as money
    damages, are inadequate to compensate for that injury;
    (3) the balance of hardships between the plaintiff and
    defendant warrants an injunction; and (4) the public
    interest would not be disserved by an injunction. eBay,
    547 U.S. at 391. We review the district court’s conclusion
    as to each eBay factor for abuse of discretion and its
    underlying factual findings for clear error. i4i Ltd. P’ship
    v. Microsoft Corp., 
    598 F.3d 831
    , 861 (Fed. Cir. 2010).
    Here, the focus is whether Presidio has established irrep-
    arable injury.
    To prove irreparable injury, a patentee must show “1)
    that absent an injunction, it will suffer irreparable harm,
    and 2) that a sufficiently strong casual nexus relates the
    alleged harm to the alleged infringement.” Apple Inc. v.
    Samsung Elecs. Co., 
    695 F.3d 1370
    , 1374 (Fed. Cir. 2012).
    To determine whether the patentee will suffer irreparable
    harm absent an injunction, the court may consider factors
    such as the nature of competition between the patentee
    and the infringer, the willingness of a patentee to license,
    and any lost sales the patentee has proven. Douglas
    Dynamics, LLC v. Buyers Prods. Co., 
    717 F.3d 1336
    ,
    1344–45 (Fed. Cir. 2013); Presidio, 702 F.3d at 1363–64;
    Robert Bosch LLC v. Pylon Mf’g Corp., 
    659 F.3d 1142
    ,
    1152–55 (Fed. Cir. 2011).
    Where irreparable injury is based on lost sales, “a
    likelihood of irreparable harm cannot be shown if sales
    would be lost regardless of the infringing conduct.” Apple
    22          PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS
    Inc. v. Samsung Elecs. Co., 
    678 F.3d 1314
    , 1324 (Fed. Cir.
    2012). Here, the district court correctly pointed out that a
    jury award of lost profits may support a finding of irrepa-
    rable harm because it necessarily results in a finding that
    the patentee lost sales and would continue to lose sales in
    the future. Presidio, 702 F.3d at 1363. The district court
    then based its conclusion as to irreparable injury on the
    jury’s lost profits award. The district court reasoned that
    “[t]he jury’s lost profits award also supports a finding of
    irreparable injury” because “the jury necessarily found
    ATC’s [550] capacitor sales caused Presidio to lose BB
    capacitor sales.” J.A. 87. In light of our reversal of the lost
    profits award for lack of proof of past lost sales, we must
    vacate the injunction.
    However, we do not decide whether this should be the
    end of the matter. The district court has discretion to
    determine whether other evidence could support a finding
    of irreparable injury. In this respect, on remand, the
    district court should reopen the record and consider
    current evidence of irreparable harm. Since March 17,
    2017, the injunction against ATC from selling 550 capaci-
    tors has been in effect. Based on the arguments and
    evidence presented to this court, it appears that this
    injunction may have created the hypothetical market
    necessary to determine whether consumers would pur-
    chase Presidio’s BB capacitors in the absence of ATC’s 550
    series capacitors. On remand, the district court should
    consider whether consumers have turned to non-
    infringing alternatives to the BB capacitor, such as the
    560L capacitor, after the 550 series capacitors became
    unavailable or whether Presidio’s sales of the BB capaci-
    tor have increased because the 550 series is no longer on
    the market. Based on this further evidence and other
    relevant evidence, the district court should determine
    whether Presidio has established irreparable injury and
    the appropriateness of an injunction.
    PRESIDIO COMPONENTS, INC.   v. AM. TECH. CERAMICS       23
    CONCLUSION
    We affirm the district court’s finding of definiteness,
    grant of absolute intervening rights, and denial of en-
    hanced damages. We reverse the award of lost profits
    because Presidio failed to show the absence of an accepta-
    ble, non-infringing substitute. On remand, the damages
    award should be limited to a reasonable royalty, and a
    new trial should be conducted as necessary to determine
    the reasonable royalty rate. We vacate the permanent
    injunction, and remand with instructions to consider the
    relevant evidence and to determine whether Presidio has
    established irreparable injury.
    AFFIRMED IN PART, REVERSED IN PART,
    VACATED IN PART, AND REMANDED
    COSTS
    No costs.