Case: 19-1524    Document: 51     Page: 1   Filed: 06/30/2020




        NOTE: This disposition is nonprecedential.


   United States Court of Appeals
       for the Federal Circuit
                  ______________________

   PACIFIC COAST BUILDING PRODUCTS, INC.,
               Plaintiff-Appellant

                             v.

   CERTAINTEED GYPSUM, INC., SAINT GOBAIN
    PERFORMANCE PLASTICS CORPORATION,
             Defendants-Appellees
            ______________________

                        2019-1524
                  ______________________

    Appeal from the United States District Court for the
 Northern District of California in No. 5:18-cv-00346-LHK,
 Judge Lucy H. Koh.
                  ______________________

                  Decided: June 30, 2020
                  ______________________

    W. SCOTT HASTINGS, Locke Lord LLP, Dallas, TX, ar-
 gued for plaintiff-appellant. Also represented by JASON E.
 MUELLER, GALYN GAFFORD, Sheppard Mullin Richter &
 Hampton LLC, Dallas, TX; MATTHEW GUY HALGREN, San
 Diego, CA.

     MATTHEW J. MOORE, Latham & Watkins LLP, Wash-
 ington, DC, argued for defendants-appellees. Also repre-
 sented by GABRIEL BELL, DIANE GHRIST, ADAM MICHAEL
Case: 19-1524    Document: 51       Page: 2   Filed: 06/30/2020




 2       PACIFIC COAST BUILDING    v. CERTAINTEED GYPSUM, INC.



 GREENFIELD, REBECCA RABENSTEIN; RICHARD GREGORY
 FRENKEL, Menlo Park, CA.
                ______________________

     Before REYNA, CHEN, and HUGHES, Circuit Judges.
 CHEN, Circuit Judge.
     Pacific Coast Building Products, Inc. (Pacific Coast)
 sued CertainTeed Gypsum, Inc. and Saint-Gobain Perfor-
 mance Plastics Corp. (collectively, CertainTeed) for patent
 infringement of claim 21 of U.S. Patent No. 9,388,568 (the
 ’568 patent) in the United States District Court for the
 Northern District of California. Claim 21 is directed to a
 drywall structure having a “scored flexural strength” of
 “about 22 pounds per 1/2 inch thickness of the structure.”
 Pacific Coast appeals from the district court’s claim con-
 struction order, which found the claim term “scored flex-
 ural strength” indefinite.
     We agree with the district court that there are multiple
 ways to measure “scored flexural strength” and that the
 specification’s lack of guidance for choosing which meas-
 urement to use renders claim 21 indefinite. Accordingly,
 we affirm the district court’s invalidity finding.
                        BACKGROUND
                              I.
     Typical drywall consists of three layers: a paper layer,
 a core material, and another layer of paper. When manu-
 facturing drywall, manufacturers produce the drywall in
 standard sizes, but contractors often need the drywall in
 smaller sizes. As a result, contractors frequently break the
 drywall into the desired size. But breaking drywall by
 hand typically does not break the drywall in a straight line.
 To solve this problem, contractors routinely cut the paper
 layer on one side of the board so that the drywall can break
 along that line—a method known as scoring.
Case: 19-1524    Document: 51      Page: 3    Filed: 06/30/2020




 PACIFIC COAST BUILDING   v. CERTAINTEED GYPSUM, INC.       3



     Typical drywall, however, is not suitable for all appli-
 cations, such as soundproofing, for example. For sound-
 proofing, two layers of core material are used and an
 additional paper layer is included between the two core lay-
 ers. The additional paper layer significantly increases the
 flexural strength of the drywall and renders the typical
 scoring method ineffective. Thus, contractors were forced
 to use other methods, such as cutting the boards with
 power tools, driving up time and cost.
     The ’568 patent aimed to fix this problem by removing
 the middle paper layer and, instead, gluing the two core
 layers together. This allowed contractors to use the scoring
 method to break the boards into the desired size.
    Pacific Coast asserted claim 21 of the ’568 patent
 against CertainTeed. Claim 21 reads:
    21. A laminated, sound-attenuating structure
    which comprises:
        a first gypsum board having two surfaces,
        the first of said two surfaces comprising an
        outer, paper-clad surface and the second of
        said two surfaces comprising an inner sur-
        face, wherein the entire inner surface of the
        first gypsum board is unclad;
        a layer of viscoelastic glue on the second of
        said two surfaces; and
        a second gypsum board over said viscoelas-
        tic glue, said second gypsum board having
        two surfaces, the first of said two surfaces
        of said second gypsum board comprising an
        outer, paper-clad surface and the second of
        said two surfaces of said second gypsum
        board comprising an inner surface, wherein
        the entire inner surface of the second gyp-
        sum board is unclad;
Case: 19-1524     Document: 51     Page: 4    Filed: 06/30/2020




 4       PACIFIC COAST BUILDING   v. CERTAINTEED GYPSUM, INC.



         a scored flexural strength of the laminated
         structure is about 22 pounds per 1/2 inch
         thickness of the structure;
         the scored flexural strength being the flex-
         ural strength of the laminated structure af-
         ter the outer, paper-clad surface of one of
         the first and second gypsum boards has
         been scored.
 ’568 patent at claim 21.
      The claim includes the term “scored flexural strength”
 with a specified value of “about 22 pounds per 1/2 inch
 thickness.” But “scored flexural strength” is a term coined
 by the patent and is not an industry term. Claim 21 fur-
 ther recites that “scored flexural strength” is “the flexural
 strength of the laminated structure after the outer, paper-
 clad surface of one of the first and second gypsum boards
 has been scored.” Id. The specification instructs that “[t]he
 measurement technique used to establish the flexural
 strength of gypsum wallboard or similar construction pan-
 els is ASTM C 473-06a ‘Standard Test Methods for the
 Physical Testing of Gypsum Panel Products’ (publication
 date Nov. 1, 2006).” Id. at col. 2 ll. 50–54. ASTM 473-06a
 sets forth the test for flexural strength as measuring the
 flexural strength in four different orientations. ASTM 473-
 06a at § 11.6 [J.A. 700–01]. Specifically, the ASTM states
 that to report the results, the report should “calculate and
 report the average breaking load in pounds-force or newtons
 for each test condition, rounded to the nearest 1 lbf (N). The
 test conditions are: (1) parallel, face up; (2) parallel, face
 down; (3) perpendicular, face up; and, (4) perpendicular,
 face down.” ASTM 473-06a at § 11.7 (emphasis added)
 [J.A. 701]. The ASTM standard thus contemplates four
 different flexural strength measurements, each calculated
 under a different test condition corresponding to a different
 board orientation. And “for each test condition,” the stand-
 ard calls for calculating an “average breaking load.” Id.
Case: 19-1524     Document: 51     Page: 5    Filed: 06/30/2020




 PACIFIC COAST BUILDING   v. CERTAINTEED GYPSUM, INC.        5



 [J.A. 701]. In other words, the standard does not report a
 single flexural strength value; it instead reports and calcu-
 lates four, with each of the four values representing an av-
 erage of multiple measurements for a given test condition.
 Moreover, it does not suggest further averaging those four
 strength values.
      The specification describes Figure 3 as showing “flex-
 ural strength results for one sample embodiment of a lam-
 inar material constructed in accordance with the present
 invention,” and then later indicates the reported results
 are actually for scored flexural strength by saying that
 “[t]he present invention (represented by H1 to H4) has a
 scored flexural strength of 22 pounds force as shown in
 FIGS. 3 and 4.” ’568 patent at col. 3 ll. 47–49, col. 6 l. 66–
 col. 7 l. 4. Figure 3 is reproduced below.




 Id. at Fig. 3.
Case: 19-1524    Document: 51        Page: 6   Filed: 06/30/2020




 6       PACIFIC COAST BUILDING     v. CERTAINTEED GYPSUM, INC.



                              II.
     At claim construction, CertainTeed challenged that
 claim 21 was indefinite because the specification was un-
 clear as to how to derive a single value for the scored flex-
 ural strength, as required by the claim. CertainTeed also
 asserted that the specification failed to identify the depth
 of the scoring mark required for testing a drywall board’s
 scored flexural strength. Furthermore, the method for con-
 verting the scored flexural strength measurement from the
 claimed 1/2-inch thickness to different board thicknesses
 was unclear.
      In response, Pacific Coast contended that a skilled ar-
 tisan knew what scoring was and the scoring depth insig-
 nificantly impacted a drywall board’s scored flexural
 strength measurement. Pacific Coast also contended that
 a skilled artisan would choose the particular ASTM test
 condition where the pressure applied to the board was par-
 allel to the scoring and with the scoring facing outward.
 Pacific Coast alternatively argued that a skilled artisan
 would average measurements from all four ASTM testing
 conditions together because Figure 3 depicted four “meas-
 ured samples” and an average value. Pacific Coast inter-
 preted these “samples” as representing a measurement in
 each of the orientations identified by the ASTM standard.
 Finally, Pacific Coast contended that a skilled artisan
 would use linear extrapolation to convert the scored flex-
 ural strengths between different thicknesses of drywall
 such as between the 1/2-inch thickness recited in the pa-
 tent to the 5/8-inch thickness of CertainTeed’s allegedly in-
 fringing product.
      The district court determined that the plain language
 of the claim and specification did not specifically explain
 how to measure a drywall’s scored flexural strength. Pa-
 cific Coast Building Prods., Inc. v. CertainTeed Gypsum,
 Inc., No. 5:18-CV-00346-LHK, 2018 WL 6268880, at *8
 (N.D. Cal. Nov. 29, 2018) [J.A. 20–21]. Even assuming
Case: 19-1524     Document: 51     Page: 7    Filed: 06/30/2020




 PACIFIC COAST BUILDING   v. CERTAINTEED GYPSUM, INC.        7



 that “scored flexural strength” can be found through appli-
 cation of the ASTM standard to a drywall board that has
 been scored, the district court observed that the ASTM
 standard disclosed multiple tests, not a single test, to
 measure the scored flexural strength. Id. [J.A. 21]. Turn-
 ing to the prosecution history, the district court inter-
 preted the applicant’s statement that “the prior art is silent
 with respect to a ‘scored flexural strength’” as further sup-
 porting that a skilled artisan would not know how to meas-
 ure the newly coined scored flexural strength. Id. at *8–9
 [J.A. 22]. In addition, the district court turned to the ex-
 trinsic evidence and determined that CertainTeed’s expert,
 Dr. Paul Miller, provided three bases for indefiniteness,
 which Pacific Coast’s expert did not rebut. The district
 court found that it was unclear (1) how deep the scoring cut
 must be for the testing, (2) which of the ASTM measure-
 ments corresponded to the claimed scored flexural
 strength, and (3) which calculation methodology would be
 used to convert the scored flexural strength between differ-
 ent thicknesses of drywall. Id. at *7–8 [J.A. 19–20]. The
 district court found that Dr. Miller’s testing demonstrated
 that this lack of clarity created “major sources of impreci-
 sion” in the claim. Id. at *12–13.
     Pacific Coast appeals the district court’s finding of in-
 definiteness. We have jurisdiction pursuant to 28 U.S.C.
 § 1295(a)(1).
                          DISCUSSION
     We review a finding of indefiniteness de novo. BASF
 Corp. v. Johnson Matthey Inc., 875 F.3d 1360, 1365 (Fed.
 Cir. 2017). However, a district court’s finding of indefinite-
 ness may be subject to underlying factual findings regard-
 ing the extrinsic evidence, and we review those findings of
 fact for clear error. Teva Pharms. USA, Inc. v. Sandoz,
 Inc., 789 F.3d 1335, 1340 (Fed. Cir. 2015).
    A patent’s specification must “conclude with one or
 more claims particularly pointing out and distinctly
Case: 19-1524     Document: 51      Page: 8    Filed: 06/30/2020




 8        PACIFIC COAST BUILDING   v. CERTAINTEED GYPSUM, INC.



 claiming the subject matter which the inventor . . . regards
 as the invention.” 35 U.S.C. § 112(b). The Supreme Court
 in Nautilus, Inc. v. Biosig Instruments, Inc. held that a pa-
 tent claim is indefinite if, when “read in light of the speci-
 fication delineating the patent, and the prosecution
 history, [the claim] fail[s] to inform, with reasonable cer-
 tainty, those skilled in the art about the scope of the inven-
 tion.” 572 U.S. 898, 901 (2014). “Reasonable certainty”
 does not require “absolute or mathematical precision.” Bi-
 osig Instruments, Inc. v. Nautilus, Inc., 783 F.3d 1374, 1381
 (Fed. Cir. 2015) (internal quotation marks omitted). Cer-
 tainTeed had the burden of proving indefiniteness by clear
 and convincing evidence. Id. at 1377.
     We have previously found claims indefinite where the
 claim requires a specific measurement or calculation, more
 than one measurement method may be used and no guid-
 ance has been provided. See Teva, 789 F.3d at 1345; Hon-
 eywell Int’l, Inc. v. ITC, 341 F.3d 1332, 1339–40 (Fed. Cir.
 2003). Teva is representative in this instance. In Teva, we
 determined that where the claim included a specific meas-
 urement of a “molecular weight” of a claimed copolymer
 and the specification did not indicate which of three meas-
 urement methods used in the industry was used (Mp, Mw,
 or Mn), the claim was indefinite. Teva, 789 F.3d at 1345.
 Because it was unclear which measurement to use for the
 claimed molecular weight and those different measure-
 ments would yield different results, the claim “failed to in-
 form with reasonable certainty those skilled in the art
 about the scope of the invention.” Id.
     On the other hand, we have also refused to require that
 a patent disclose details as to every possible variable that
 may affect the calculation of a measured value or range of
 values recited in a patent claim. See Koninklijke Philips
 N.V. v. Zoll Med. Corp., 656 F. App’x 504 (Fed. Cir. 2016).
 In Zoll, for example, we did not find error in a jury’s verdict
 that a claim was definite even though the specification did
 not provide details about some parameters for the testing
Case: 19-1524     Document: 51      Page: 9     Filed: 06/30/2020




 PACIFIC COAST BUILDING   v. CERTAINTEED GYPSUM, INC.          9



 conditions and equipment, which allegedly introduced
 some imprecision into the measurement of an attribute re-
 cited in the claims. Id. at 526. We found that the jury could
 have reasonably “viewed the evidence on” those parame-
 ters as creating only a relatively minor, inconsequential
 source of imprecision in the claims. Id. Further, there was
 expert testimony to support the view that a skilled artisan
 would have understood how to handle those parameters
 when reading the claim. Id.
      We agree with the district court that the ’568 patent
 fails to provide guidance to a skilled artisan for how to
 measure the newly coined characteristic “scored flexural
 strength” with reasonable certainty. While the claims re-
 cite a particular value for “scored flexural strength,” i.e.,
 “about 22 pounds per 1/2 inch thickness,” the claims and
 specification fail to explain what the value represents or
 how to consistently and reproducibly measure this new
 characteristic.
     The specification’s reference to ASTM 473-06a does not
 adequately fill the void. First of all, this standard is for
 measuring multiple flexural strength values with a given
 board positioned at different orientations; it is not directed
 to “scored flexural strength.” Moreover, even assuming
 that the patent discloses using the ASTM standard for
 measuring scored flexural strength of a scored board, the
 ASTM provides four different test conditions of measuring
 flexural strength of a board. The ASTM describes the
 standard as four separate measurements and specifically
 instructs a tester to “calculate and report the average
 breaking load in pounds-force or newtons for each test con-
 dition, rounded to the nearest 1 lbf (N). The test conditions
 are: (1) parallel, face up; (2) parallel, face down; (3) perpen-
 dicular, face up; and, (4) perpendicular, face down.” ASTM
 473-06a at § 11.7 [J.A. 701]. Contrary to Pacific Coast’s
 contention, the ASTM does not suggest that flexural
 strength can be represented by any one of the measure-
 ments alone or that all four can be averaged together. The
Case: 19-1524    Document: 51      Page: 10     Filed: 06/30/2020




 10       PACIFIC COAST BUILDING   v. CERTAINTEED GYPSUM, INC.



 specification’s bare reference to the standard thus does not
 inform a skilled artisan how to arrive at a single scored
 flexural strength measurement.
      Figure 3 of the patent does not counsel otherwise. Even
 assuming Figure 3 presents data for the scored flexural
 strength, 1 the table is not clear as to what the different
 samples (H1–H4) represent. The specification does not in-
 dicate whether these samples are measurements in differ-
 ent board orientations, if the measurements are all in the
 same configuration, or if each sample is an average of sev-
 eral measurements in different orientations. See ’568 pa-
 tent col. 6 ll. 35–38, col. 6 l. 66–col. 7 l. 2. Such ambiguity
 fails to provide reasonable certainty to a skilled artisan as
 to how to assess whether a given drywall board has a
 scored flexural strength of about 22 pounds per 1/2-inch
 thickness.
     In addition to showing that a skilled artisan would not
 know by what means to measure the claimed “scored flex-
 ural strength,” the extrinsic evidence shows that this am-
 biguity in addition to others the district court found create
 significant problems for measuring scored flexural
 strength with any reasonable certainty. The extrinsic evi-
 dence in this case consists of detailed testing and analysis
 from CertainTeed’s expert, Dr. Miller, and a declaration
 from Pacific Coast’s expert, Mr. Matthew Risinger. But the
 record does not reflect that Mr. Risinger ever conducted
 any tests of his own, and his testimony, apart from two par-
 agraphs, is largely irrelevant to the question in this appeal.
     Dr. Miller testified that the score depth affects the re-
 sult of the scored flexural tests, that the configuration of



      1   The specification is inconsistent as to whether Fig-
 ure 3 reports the flexural strength or the scored flexural
 strength, thus compounding the lack of certainty. ’568 pa-
 tent col. 6 ll. 35–38, col. 6 l. 66–col. 7 l. 2.
Case: 19-1524    Document: 51      Page: 11   Filed: 06/30/2020




 PACIFIC COAST BUILDING   v. CERTAINTEED GYPSUM, INC.      11



 the test and whether the results were averaged together
 significantly affected the value of the measurement, and
 that there are at least two methods of converting the meas-
 urement between board thicknesses that produce signifi-
 cantly differing results. In addition, Dr. Miller provided
 thorough test results supporting his conclusions. We agree
 with the district court that “Dr. Miller’s testing demon-
 strates that there are major sources of imprecision result-
 ing from the lack of clarity about the score depth and the
 applicable testing methodology.” Pacific Coast, 2018 WL
 6268880 at *12–13 (citing Zoll, 656 F. App’x 504 (Fed. Cir.
 2016)) [J.A. 28–29].
     In comparison, Pacific Coast has not pointed to any ex-
 trinsic evidence that supports its claim that a skilled arti-
 san would either know which of the ASTM’s configurations
 to choose or to average the tests together. Nor does Pacific
 Coast identify any evidence, apart from Mr. Risinger’s con-
 clusory testimony, that the scoring depth does not matter.
      Regarding the conversion between board thicknesses,
 Dr. Miller explained that a skilled artisan could have used
 either a linear extrapolation or the pound per square inch
 (psi) calculation. As the district court properly found, “Dr.
 Miller’s results show that the psi method and the linear
 extrapolation method lead to different scored flexural
 strength results such that a panel might infringe under one
 conversion technique but not the other.” Id. at 20. Pacific
 Coast does not present any evidence that at the time of the
 invention, a skilled artisan would have known to use linear
 extrapolation rather than the psi calculation. At best, Pa-
 cific Coast asserts that a later version of the ASTM pub-
 lished in 2017, several years after the patent’s filing date,
 memorializes the understanding of a skilled artisan. Noth-
 ing in the ASTM or any evidence identified by Pacific Coast
 supports this conclusion. Even if the standard does memo-
 rialize the industry understanding in 2017, nothing sug-
 gests this was the understanding when the ’568 patent was
 filed in 2007.
Case: 19-1524    Document: 51     Page: 12    Filed: 06/30/2020




 12      PACIFIC COAST BUILDING   v. CERTAINTEED GYPSUM, INC.



     The evidence taken together clearly indicates that the
 various choices that could be made for determining the
 scored flexural strength of a board are material, contrary
 to Pacific Coast’s arguments. Pacific Coast has provided
 insufficient evidence of its own to rebut this evidence, and
 instead attempts to take Dr. Miller’s testimony out of con-
 text and cast it in a light that supposedly creates claim
 clarity. Pacific Coast’s recharacterizations are unpersua-
 sive. Accordingly, we agree with the district court that the
 facts of this case are similar to Teva and distinguishable
 from Zoll, and that a skilled artisan would have had no rea-
 sonable certainty in trying to figure out how to calculate a
 single value for the scored flexural strength of a drywall
 board.
                        CONCLUSION
     We have considered Pacific Coast’s remaining argu-
 ments and find them unpersuasive. We see no clear error
 in the district court’s factual findings, and based on this
 evidence affirm the district court’s finding that claim 21 of
 the ’568 patent is invalid as indefinite because it does not
 inform a skilled artisan how to measure or calculate the
 scored flexural strength.
                        AFFIRMED
