  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.
