Trials@uspto.gov
`Tel: 571-272-7822
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` Paper 49
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` Entered: March 25, 2015
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`_______________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`_______________
`
`LAIRD TECHNOLOGIES, INC.,
`Petitioner,
`
`v.
`
`GRAFTECH INTERNATIONAL HOLDINGS, INC.,
`Patent Owner.
`_______________
`
`Case IPR2014-00023
`Patent 6,482,520 B1
`_______________
`
`
`Before BRIAN J. McNAMARA, BARRY L. GROSSMAN, and
`J. JOHN LEE, Administrative Patent Judges.
`
`GROSSMAN, Administrative Patent Judge.
`
`
`
`FINAL WRITTEN DECISION
`35 U.S.C. § 318(a) and 37 C.F.R. § 42.73
`
`
`
`
`
`

`

`IPR2014-00023
`Patent 6,482,520 B1
`
`
`I. INTRODUCTION
`
`Laird Technologies, Inc. (“Petitioner”) filed a Corrected Petition
`
`requesting an inter partes review of claims 1, 2, 21–24, and 26–29 of U.S.
`
`Patent No. 6,482,520 B1 (“the ’520 patent”). Paper 7 (“Pet.”). On March
`
`26, 2014, we instituted an inter partes review of claims 1, 2, 22–24, and 27–
`
`29 under 35 U.S.C. § 103 for obviousness over Inoue (Ex. 1016) and the
`
`Grafoil Manual (Ex. 1008); and claims 21 and 26 under 35 U.S.C. § 103 for
`
`obviousness over Inoue, the Grafoil Manual, and the Thermagon Paper (Ex.
`
`1015). Decision on Institution of Inter Partes Review, Paper 11
`
`(“Decision”).
`
`GrafTech International Holdings, Inc. (“Patent Owner”) filed a
`
`Confidential Patent Owner Response (Paper 24, “Confidential PO. Resp.”)
`
`and a Redacted Patent Owner Response (Paper 23, “Redacted PO Resp.”).
`
`Petitioner filed a Reply (Paper 32, “Reply”).
`
`We granted Patent Owner’s motion to seal Exhibits 2034–2040, 2047,
`
`2053–2063, and 2074–2091 (collectively the “Sealed Exhibits”) and portions
`
`of the Patent Owner Response. Paper 30.
`
`Patent Owner did not file a motion to amend the claims. Claims 24
`
`and 26–29 of the ’520 Patent, however, have been statutorily disclaimed
`
`and, thus, are no longer considered in this inter partes review. See Paper
`
`No. 22; Redacted PO Resp. 3 (“Claims 24, 26, 27, 28, and 29 of the ‘520
`
`Patent . . . have been statutorily disclaimed.”). Accordingly, only claims 1,
`
`2, and 21–23 remain in this proceeding.1
`
`
`1 “[A] patent owner may file a statutory disclaimer of one or more
`challenged claims to streamline the proceedings. Where no challenged
`claims remain, the Board would terminate the proceeding. Where one or
`
`
`
`2
`
`

`

`IPR2014-00023
`Patent 6,482,520 B1
`
`
`Also before us is Patent Owner’s Motion to Exclude Evidence (Paper
`
`37), Petitioner’s Opposition to the Motion (Paper 42), and Patent Owner’s
`
`Reply (Paper 44); as well as Patent Owner’s Observations on the Cross
`
`Examination of Richard Feinberg (Paper 38), and Petitioner’s Response to
`
`Patent Owner’s Observations (Paper 41).
`
`An oral hearing was held on December 15, 2014. A transcript of the
`
`hearing is included in the record. Paper 48 (“Tr.”).
`
`We have jurisdiction under 35 U.S.C. § 6(c). This final written
`
`decision is issued pursuant to 35 U.S.C. § 318(a) and 37 C.F.R. § 42.73.
`
`For the reasons that follow, we determine Petitioner has shown, by a
`
`preponderance of the evidence, that claims 1, 2, 21, 22, and 23 are
`
`unpatentable.
`
`A. The ’520 Patent
`
`The ’520 patent has been through two ex parte reexaminations. The
`
`first reexamination resulted in Ex Parte Reexamination Certificate 6,482,520
`
`C1, issued November 13, 2007 (“’520 C1”) (generally referred to as the
`
`“first reexamination”). The second reexamination resulted in Ex Parte
`
`Reexamination Certificate 6,482,520 C2, issued February 3, 2009 (“’520
`
`C2”) (generally referred to as the “second reexamination”). Both ’520 C1
`
`and ’520 C2 are included as part of Exhibit 1001.
`
`The invention in the challenged claims of the ’520 patent relates,
`
`generally, to a thermal management system for dissipating the heat
`
`generated by electronic components, such as microprocessors and integrated
`
`
`more challenged claims remain, the Board’s decision on institution would be
`based solely on the remaining claims.” Office Patent Trial Practice Guide,
`77 Fed. Reg. 48,756, 48,764–65 (Aug. 14, 2012) (citing Sony Computer
`Entm’t Am. Inc. v. Dudas, 2006 WL 1472462 (E.D. Va. 2006)).
`
`
`
`3
`
`

`

`IPR2014-00023
`Patent 6,482,520 B1
`
`circuits. Ex. 1001, col. 5, ll. 23–34. The claimed invention uses a thermal
`
`management system that comprises two elements: (1) a heat source with an
`
`external surface; and (2) an anisotropic flexible graphite sheet. Anisotropy
`
`refers to a difference in properties in different directions. Redacted PO
`
`Resp. 8 (citing Ex. 2005 ¶ 47). Thermal anisotropy of a material is defined
`
`by the material’s in-plane and through-plane thermal conductivities. Id.
`
`(citing Ex. 2005 ¶ 81). In this context, “in-plane” refers to the “a” direction
`
`and runs along the length of the material; “through-plane” refers to the “c”
`
`direction and runs perpendicular to the “a” plane, as shown in the
`
`illustrations below. Ex. 2005 ¶ 81.
`
`Illustration from Ex. 2005 ¶ 81 showing
`“c-direction” through plane and
`“a-direction” in-plane thermal conductivity.
`
`
`
`To be anisotropic with regard to thermal conductivity, a material’s through-
`
`plane and in-plane thermal conductivities must be different. Id. ¶ 82. If they
`
`were the same, they would be thermally isotropic. Id.
`
`The graphite sheet in the challenged claims is formed of compressed
`
`particles of exfoliated natural graphite (“CPEG”) that has a “planar area
`
`greater than the area of the external surface of the heat source.” Ex. 1001,
`
`col. 3, ll. 9–15; Ex. 1001, ’520 C1, col. 1, ll. 26–40; see Redacted PO Resp.
`
`1. The CPEG sheet in all the challenged claims has two planar surfaces, and
`
`
`
`4
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`

`

`IPR2014-00023
`Patent 6,482,520 B1
`
`its thermal conductivity along one of those surfaces is at least about twenty
`
`times greater than along the other surface. Id.
`
`Graphite sheets made from CPEG are in the prior art, as is the process
`
`for making these sheets. Ex. 1001, col. 6, ll. 3–21 (citing U.S. Patent No.
`
`3,404,061 (“Shane”)). Shane is incorporated by reference into the ’520
`
`patent. Shane is Exhibit 1013 in this proceeding. Shane is not a reference
`
`applied by Petitioner against the claims to establish unpatentability. Shane,
`
`however, is an important and substantive piece of admitted prior art that
`
`establishes the basic characteristics of the CPEG material used in the
`
`claimed invention and known in the art. These basic characteristics are
`
`discussed below.
`
`Figure 1, shown below, illustrates the general components of the
`
`thermal management system disclosed and claimed in the ’520 patent.
`
`Figure 1 of the ’520 patent.
`
`
`
`As shown in Figure 1, thermal management system 10 includes
`
`thermal interface 20 that forms an operative connection with external surface
`
`100a of electronic component 100. Ex. 1001, col. 5, ll. 38–42. Thermal
`
`
`
`5
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`

`

`IPR2014-00023
`Patent 6,482,520 B1
`
`interface 20 is an anisotropic, flexible sheet made from CPEG. Id. at ll. 49–
`
`52.
`
`B. Exemplary Claim
`
`The sole independent claim, claim 1, is directed to a thermal
`
`management system. Claim 1 is reproduced below as printed in Ex. 1001,
`
`’520 C1 (brackets and emphases in original).
`
` 1. A thermal management system comprising a heat
`source having an external surface and [a thermal interface
`which comprises] an anisotropic flexible graphite sheet
`formed [by compressing exfoliated] of compressed
`particles of exfoliated natural graphite and having a planar
`area greater than the area of the external surface of the
`heat source, the flexible graphite sheet having first and
`second major planar surfaces and having axes of higher
`thermal conductivity parallel to said major planar surfaces
`such that the ratio of thermal conductivity of the flexible
`graphite sheet parallel to said major planar surfaces to
`the thermal conductivity of the flexible graphite sheet
`transverse to said major surfaces is at least about 20, one
`of said major planar surfaces being in direct operative
`contact with the heat source.
`
`C. Scope and Content of the Prior Art
`
`1. Shane (Exhibit 1013)
`
`Shane is incorporated by reference into the ’520 patent. Ex. 1001,
`
`col. 6, ll. 3–5. Shane issued on October 1, 1968, based on an application
`
`filed on April 15, 1963. Shane is prior art under 35 U.S.C. § 102(b).
`
`Shane discloses a flexible sheet material that consists essentially of
`
`graphite, which possesses anisotropic, or highly directional, properties.
`
`Ex. 1013, col. 1, ll. 10–19; see also Redacted PO Resp. 46 (“Shane does
`
`disclose a process for producing CPEG sheet material and does discuss the
`
`anisotropic thermal properties of a CPEG sheet.”). The graphite sheet in
`
`
`
`6
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`

`

`IPR2014-00023
`Patent 6,482,520 B1
`
`Shane has “excellent flexibility” and “good strength.” Id. at col. 4, l. 46.
`
`The graphite sheet can be “pure graphite free of any binders,” or,
`
`alternatively, “additives, suitable organic and inorganic materials, can be
`
`incorporated therein so as to modify the nature or properties thereof.” Id. at
`
`col. 13, ll. 56–59.
`
`Shane discloses “[t]he supple graphite sheet material can be provided
`
`with a uniform thickness . . . of . . . about 0.0001 inch (0.1 mil)” and can be
`
`used as an insulating barrier “in a very small space.” Ex. 1013, col. 13,
`
`ll. 16–21, 31–36. Shane also discloses that the degree of anisotropy
`
`increases with increasing density; the greater the density, the greater the
`
`degree of anisotropy possessed by the flexible graphite sheet material. Id. at
`
`col. 4, ll. 65–69. The graphite sheet disclosed in Shane “possesses either
`
`low or high thermal conductivity, dependent upon the orientation.” Id. at
`
`col. 13, ll. 10–11. It also has “excellent thermal insulating properties from
`
`the cryogenic range up to 6700 °F.” Id. at col. 13, ll. 18–19. Shane
`
`concludes that a “very effective insulating barrier is thus available in a very
`
`small space.” Id. at col. 13, ll. 19–21.
`
`Shane also discloses that the flexible CPEG sheet has “a wide range of
`
`uses,” such as “an insulating material and/or as a thermal conductive
`
`material,” as “chemically inert gaskets,” or as “very effective radiant heat
`
`barriers.” Ex. 1013, col. 13, ll. 43–46, 49–50, col. 14, l. 73. Shane’s flexible
`
`graphite sheet material can “provide structural shapes of any desired
`
`thickness, rigidity, and density.” Id. at col. 15, ll. 45–49.
`
`Patent Owner’s Declarant, Carl Zweben, Ph.D., acknowledges that
`
`Shane discloses a process for producing CPEG sheet material and discusses
`
`the anisotropic thermal properties of a CPEG sheet, but opines that the
`
`
`
`7
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`

`IPR2014-00023
`Patent 6,482,520 B1
`
`information in Shane is “no better than that of the Grafoil Manual.”
`
`Ex. 2005 ¶ 210.
`
`2. Inoue (Ex. 1016)
`
`Inoue discloses cooling semiconductor element 3 by bringing a
`
`“carbonaceous sheet [4] into contact” with the heat source (i.e.,
`
`semiconductor element 3). Ex. 1016 ¶ 6. The carbonaceous sheet has a
`
`planar area larger than the semiconductor element. Id. at Fig. 2 (shown
`
`below).
`
`Fig. 2 of Inoue (Ex. 1016) showing carbonaceous sheet 4
`and semiconductor (heat source) 3.
`
`
`
`Inoue also discloses the benefits of “using graphite with a high degree
`
`of orientation as the carbonaceous sheet.” Id. ¶ 7. Additionally, Inoue
`
`discloses “the carbonaceous sheet is a sheet with anisotropic thermal
`
`conductivity” and is “graphite with a high degree of orientation.” Id. ¶ 13.
`
`3. Grafoil Manual (Exhibit 1008)
`
`The Grafoil material described in the Grafoil Manual (Ex. 1008) is the
`
`same material, CPEG, that is disclosed in Shane (Ex. 1013). Redacted PO
`
`Resp. 35 (“Grafoil is CPEG.”). The Graphite Manual discloses that, at about
`
`70°F, the ratio of thermal conductivity of Grafoil along its length and width
`
`(about 960 BTU*in/hr*1°F) to its thermal conductivity through its thickness
`
`(about 36 BTU*in/hr*1°F) is about 28:1. See Ex. 1008, Figs. 5, 6; Pet. 27.
`
`
`
`8
`
`

`

`IPR2014-00023
`Patent 6,482,520 B1
`
`
`4. Thermagon Paper (Ex. 1015)
`
`The “Thermagon Paper” is a Technical Paper from the Thermagon,
`
`Inc. website. The Thermagon Paper is titled, “Thermal Resistance of
`
`Interface Materials as a Function of Pressure.” Ex. 1015. Patent Owner
`
`asserts that the thermal interface materials disclosed in the Thermagon Paper
`
`“are a wholly different type of thermal management solution tha[n] those of
`
`the challenged claims of the ‘520 Patent, i.e., heat spreaders.” Redacted PO
`
`Resp. 49. Patent Owner recognizes, however, that the Thermagon Paper
`
`relates to thermal management, as does the claimed invention. The
`
`Thermagon Paper states that a “very large factor in reducing thermal
`
`interface resistance is the application of pressure.” Ex. 1015, 1. The Paper
`
`states that the use of excessive pressure can create stresses detrimental to the
`
`function of an electronic system. Id. In some cases, 10 psi is all that can be
`
`tolerated, but in most cases any pressure over 50 psi would be considered
`
`detrimental. Id.
`
`D. Level of Ordinary Skill
`
`Petitioner relies on the Declaration of Mr. Bagot to assert that a
`
`person of ordinary skill in the art would have had a Bachelor of Science
`
`degree in materials science or an engineering discipline, and five or more
`
`years of experience in the field of the management of heat in electronic
`
`devices using flexible graphite sheets. Pet. 17 (citing Ex. 1012 ¶ 19).
`
`Dr. Zweben’s opinion regarding the level of ordinary skill opinion of
`
`a person of ordinary skill in the art “differs slightly” from that asserted by
`
`Petitioner. Ex. 2005 ¶ 135. In Dr. Zweben’s opinion, a person of ordinary
`
`skill in the art in the field of the ’520 patent would be one with at least a
`
`Bachelor’s degree in an engineering discipline (such as mechanical
`
`
`
`9
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`

`IPR2014-00023
`Patent 6,482,520 B1
`
`engineering or electrical engineering) or an applied physics discipline, and at
`
`least three to five years of experience with thermal management. Id. Dr.
`
`Zweben agrees that the patentability of the challenged claims does not
`
`depend on whether Petitioner’s or Patent Owner’s asserted definition is used.
`
`Id. ¶ 137. We agree with Dr. Zweben that the differences with the position
`
`asserted by Petitioner are slight, and, in our view, insignificant in resolving
`
`the issue of the patentability of the challenged claims.
`
`II. ANALYSIS
`
`A. Claim Construction
`
`In an inter partes review, claim terms in an unexpired patent are
`
`interpreted according to their broadest reasonable construction in light of the
`
`specification of the patent in which they appear. 37 C.F.R. § 42.100(b); In
`
`re Cuozzo Speed Technologies LLC, No. 2014-1301, 2015 WL 448667, at
`
`*5–*8 (Fed. Cir. Feb. 4, 2015) (“Congress implicitly adopted the broadest
`
`reasonable interpretation standard in enacting the AIA,” and “the standard
`
`was properly adopted by PTO regulation.”); Office Patent Trial Practice
`
`Guide, 77 Fed. Reg. 48,756, 48,766 (Aug. 14, 2012). Claim terms also are
`
`given their ordinary and customary meaning, as would be understood by one
`
`of ordinary skill in the art in the context of the entire disclosure. In re
`
`Translogic Tech., Inc., 504 F.3d 1249, 1257 (Fed. Cir. 2007). If an inventor
`
`acts as his or her own lexicographer, the definition must be set forth in the
`
`specification with reasonable clarity, deliberateness, and precision.
`
`Renishaw PLC v. Marposs Societa’ per Azioni, 158 F.3d 1243, 1249 (Fed.
`
`Cir. 1998). If a feature is not necessary to give meaning to what the inventor
`
`means by a claim term, it would be “extraneous” and should not be read into
`
`
`
`10
`
`

`

`IPR2014-00023
`Patent 6,482,520 B1
`
`the claim. Renishaw PLC, 158 F.3d at 1249; E.I. du Pont de Nemours & Co.
`
`v. Phillips Petroleum Co., 849 F.2d 1430, 1433 (Fed. Cir. 1988).
`
`Petitioner does not assert any specific claim construction. Pet. 17–18.
`
`Patent Owner submits that three phrases from the challenged claims of
`
`the ’520 Patent should be construed: (1) “thermal management system”;
`
`(2) “heat source”; and (3) “flexible graphite sheet formed of compressed
`
`particles of exfoliated natural graphite.” Redacted PO Resp. 21. Petitioner
`
`recommends that we “should not construe the terms, as doing so would be
`
`offering an advisory opinion regarding the scope of those terms.” Reply 10.
`
`We construe the proposed terms to avoid any ambiguity in their
`
`meaning, and to establish both what the claims mean and what they do not
`
`mean.
`
`1. Thermal Management System
`
`The phrase “thermal management system” is in the preamble of the
`
`challenged claims (“A thermal management system comprising . . .”).
`
`Patent Owner proposes that the broadest reasonable interpretation of the
`
`phrase “thermal management system” is “an apparatus that effectively
`
`facilitates the dissipation of heat from a heat source.” Redacted PO Resp.
`
`21–22. The Specification uses this same description in describing the
`
`“background of the art.” Ex. 1001, col. 2, ll. 32–38. The Specification also
`
`uses this description in referring to the intended use of the invention
`
`disclosed in the ’520 patent. Id. at col. 5, ll. 23–24.
`
`Patent Owner’s Declarant, Carl Zweben, Ph.D., opines that Patent
`
`Owner’s proposed construction is correct. Ex. 2005 ¶ 140. Dr. Zweben,
`
`however, also provides a detailed definition of thermal dissipation that
`
`
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`11
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`

`IPR2014-00023
`Patent 6,482,520 B1
`
`suggests that the term “dissipation” has meaning more specific than the
`
`claim construction proposed. According to Dr. Zweben,
`
`“[t]hermal dissipation is the process by which heat
`generated by a heat source is removed from the heat
`source by distributing the heat over an increased area or
`volume by conduction and then removing the heat by
`convection and/or
`radiation
`into
`the
`surrounding
`environment (e.g., air or liquid) using either active (e.g.,
`fan or pump) or passive fluid flow and/or radiation.”
`
`Ex. 2005 ¶ 90.
`
`When describing the invention in the Summary of the Invention, the
`
`Specification states that “an object of the present invention [is] to provide a
`
`thermal management system for a heat source,” without referring to
`
`“dissipation” of heat. Ex. 1001, col. 2, ll. 41–42. In light of Dr. Zweben’s
`
`specific description of thermal dissipation, which includes fans and pumps,
`
`the broadest reasonable construction in light of the Specification of the ’520
`
`patent of the phrase “thermal management system” is a system that manages
`
`heat.
`
`2. Heat Source
`
`Patent Owner proposes that the broadest reasonable interpretation of
`
`the phrase “heat source” is “an item that generates heat such that, if not
`
`dissipated, it will hinder the operation of the heat source and/or the unit of
`
`which the item is a part.” Redacted PO Resp. 22. Dr. Zweben opines that
`
`Patent Owner’s proposed construction is correct. Ex. 2005 ¶ 145.
`
`When describing the invention in the Summary of the Invention, the
`
`Specification states that “an object of the present invention [is] to provide a
`
`thermal management system for a heat source,” without referring to
`
`hindering the operation of the heat source. Ex. 1001, col. 2, ll. 41–42.
`
`
`
`12
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`

`IPR2014-00023
`Patent 6,482,520 B1
`
`Accordingly, the broadest reasonable construction in light of the
`
`Specification of the ’520 patent of the phrase “heat source” simply is a
`
`source of heat.2
`
`3. Flexible Graphite Sheet Formed of Compressed Particles of
`
`Exfoliated Natural Graphite
`
`Patent Owner proposes that the broadest reasonable interpretation of
`
`“flexible graphite sheet formed of compressed particles of exfoliated natural
`
`graphite” is a “flexible graphite sheet formed of compressed particles of
`
`exfoliated natural graphite that is coherent and has good handling strength.”
`
`Redacted PO Resp. 22. Dr. Zweben opines that Patent Owner’s proposed
`
`construction is correct. Ex. 2005 ¶ 147. He bases his opinion on a single
`
`passage in the Specification that “[f]lexible graphite sheet is coherent, with
`
`good handling strength, and is suitably compressed, such as by rollpressing.”
`
`Id. ¶ 148.
`
`The Specification states that thermal interface 20 “preferably
`
`comprises an anisotropic flexible graphite sheet.” Ex. 1001, col. 5, ll. 49–
`
`50. The Specification then states that “[b]y an anisotropic flexible graphite
`
`sheet is meant a sheet of compressed, exfoliated graphite, especially natural
`
`graphite.” Id. at col. 5, ll. 50–52. Based on the Specification, we determine
`
`that a construction incorporating the quality of being coherent with good
`
`handling strength is too limiting; it improperly reads limitations that are not
`
`required into the claims. See Specialty Composites v. Cabot Corp., 845 F.2d
`
`
`2 “These are ordinary, simple English words whose meaning is clear and
`unquestionable. There is no indication that their use in this particular
`conjunction changes their meaning. They mean exactly what they say.”
`Chef America, Inc. v. Lamb-Weston, Inc., 358 F. 3d 1371, 1373 (Fed. Cir.
`2004).
`
`
`
`13
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`

`IPR2014-00023
`Patent 6,482,520 B1
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`981, 987 (Fed. Cir.1988) (“Where a specification does not require a
`
`limitation, that limitation should not be read from the specification into the
`
`claims.”).
`
`Accordingly, we determine that the broadest reasonable interpretation
`
`of the phrase “flexible graphite sheet formed of compressed particles of
`
`exfoliated natural graphite” does not include the quality of the sheet being
`
`coherent with good handling strength. This phrase does not require
`
`additional specific construction for purposes of this decision.
`
`B. Asserted Grounds of Unpatentability
`
`The Supreme Court has made clear that we apply “an expansive and
`
`flexible approach” to the question of obviousness. KSR Int’l Co. v. Teleflex
`
`Inc., 550 U.S. 398, 415 (2007). Whether a patent claiming the combination
`
`of prior art elements would have been obvious is determined by whether the
`
`improvement is more than the predictable use of prior art elements according
`
`to their established functions. Id. at 417. To reach this conclusion, however,
`
`requires more than a mere showing that the prior art includes separate
`
`references covering each separate limitation in a claim under examination.
`
`Unigene Labs., Inc. v. Apotex, Inc., 655 F.3d 1352, 1360 (Fed. Cir. 2011).
`
`Rather, obviousness requires the additional showing that a person of
`
`ordinary skill at the time of the invention would have selected and combined
`
`those prior art elements in the normal course of research and development to
`
`yield the claimed invention. Id. As the Supreme Court recognized, in many
`
`cases a person of ordinary skill “will be able to fit the teachings of multiple
`
`patents together like pieces of a puzzle,” recognizing that a person of
`
`ordinary skill “is also a person of ordinary creativity, not an automaton.”
`
`
`
`14
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`

`IPR2014-00023
`Patent 6,482,520 B1
`
`KSR, 550 U.S. at 420–21. Against this general background, we consider the
`
`references, other evidence, and arguments on which Petitioner relies.
`
`1. Obviousness Based on Inoue and Grafoil Manual
`
`a. Claims 1, 2, 22, and 23
`
`Inoue was considered in both the first and second reexaminations.
`
`E.g., Ex. 1003, 214; Ex. 1004, 3. In the first reexamination, the Examiner
`
`found that “Inoue fails to teach that the disclosed graphite sheet comprises
`
`either ‘particles of exfoliated graphite’ or ‘high density graphite formed
`
`from finely divided carbonaceous particles.’” Ex. 1003, 214. In the second
`
`reexamination, the Examiner made a similar determination, finding that
`
`Inoue “fail[s] to teach or suggest the use of anisotropic graphite sheets
`
`formed of particles of exfoliated graphite or high density graphite formed
`
`from finely divided carbonaceous particles.” Ex. 1004, 167. Petitioner
`
`recognizes these prior considerations and findings. Pet. 35 (“In sum,
`
`therefore, the only difference between claim 1 and the Inoue Reference is the
`
`specific type of graphite sheet that is used.”); see also Tr. 9, l. 9 (“Inoue does
`
`not disclose CPEG at all.”). For claim 1, Petitioner relies on the Grafoil
`
`Manual (Ex. 1008) to compensate for the deficiencies in the Inoue disclosure
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`noted in the reexaminations (Pet. 35).
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`Petitioner asserts that Inoue discloses “the usefulness of placing a
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`‘carbonaceous sheet’ . . . in contact with an electronic heat source (e.g., a
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`semiconductor) to dissipate heat from the heat source.” Pet. 29. According
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`to Petitioner, Inoue discloses in Figure 2, shown above, carbonaceous sheet
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`4 having a larger surface area than semiconductor element (heat source) 3.
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`Id. Petitioner concludes that a person of ordinary skill in the art would have
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`been motivated to combine the teachings of Inoue with the disclosure of the
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`Patent 6,482,520 B1
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`Grafoil Manual3 because both taught graphite sheets for managing heat in
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`electronic devices. Pet. 30. According to Petitioner, substituting the
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`graphite sheets disclosed in the Grafoil® Manual for the sheets disclosed in
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`Inoue “would yield the merely predictable result of improved spreading of
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`heat from the heat source.” Id.
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`Claim 1 requires the ratio of thermal conductivity of the flexible
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`graphite sheet parallel to the major planar surfaces (in-plane)4 to the thermal
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`conductivity of the flexible graphite sheet transverse to the major surfaces
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`(through plane) is “at least about 20.” The Grafoil Manual discloses that, at
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`about 70°F, the ratio of thermal conductivity of Grafoil along its length and
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`width (about 960 BTU*in/hr*1°F) to its thermal conductivity through its
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`thickness (about 36 BTU*in/hr*1°F) is about 28:1. See Ex. 1008, Figs. 5, 6;
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`Pet. 27. The ratio of thermal conductivity in the in-plane and through-plane
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`directions of 28:1 in the Grafoil Manual meets the limitation of “at least
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`about 20,” required by claim 1.
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`Petitioner’s Declarant, William A. Bagot, opines that a person having
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`ordinary skill in the art “would have been motivated to combine” the
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`teachings of lnoue with the Grafoil® Manual because both references
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`
`3 As stated in our Decision to Institute, Petitioner used the phrase “Grafoil
`Prior Art” as a collective term for four separate and distinct references.
`Decision 18. Petitioner asserts that the claims challenged in Ground 4 of the
`Petition, on which we instituted this review, are unpatentable “in view of the
`Grafoil® Website and Specification and/or the Grafoil® Website and
`Manual” without stating any meaningful distinction between the separate
`disclosures of the four references comprising the Grafoil Prior Art. Pet. 29.
`In instituting this inter partes review, we relied on the Grafoil Manual,
`which appears to be the most comprehensive of the four “Grafoil Prior Art”
`references. Decision 18.
`
` See Redacted PO Resp. 8.
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`“concern compounds for use in systems for managing heat in electronic
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`devices.” Ex. 1012 ¶ 45. Mr. Bagot opines that it would have been obvious
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`to combine the references because Inoue, like the Grafoil® Manual,
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`concerns small and lightweight cooling structures with good heat dissipation
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`ability (including for use with semiconductors).” Id. Mr. Bagot also states
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`that a reason why a person of ordinary skill would have used the Grafoil
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`material in the Inoue device is that it would provide the predictable result of
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`a device with “slightly better heat spreading because Grafoil® is slightly
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`better than the graphite sheeting in Inoue at spreading heat. Further, there is
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`nothing in Inoue that would discourage a person having ordinary skill in the
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`art from using Grafoil® in the Inoue system.” Id. ¶ 53.
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`Patent Owner takes a different view of the disclosures in the
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`references and the rationale for combining them.
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`Patent Owner acknowledges that “CPEG was known for decades prior
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`to the filing of the application that matured as the ’520 Patent.” Redacted
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`PO Resp. 2–3; see also Decision 7 (“Shane [Ex. 1013] apprises the ordinary
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`artisan of CPEG’s benefits and provides a roadmap for how to make and use
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`CPEG.”). Shane (Ex. 1013) explains in detail all of the properties of CPEG,
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`and also spells out exactly how to manufacture the CPEG product that
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`became Grafoil. Decision 7.
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`Patent Owner does not dispute that the Grafoil material described in
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`the Grafoil Manual (Ex. 1008) is the same material, CPEG, that is disclosed
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`in Shane (Ex. 1013). Redacted PO Resp. 35 (“Grafoil is CPEG.”); see also
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`Tr. 39, ll. 22–24.5 Patent Owner argues that the patentability of the ’520
`
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`5 “Q: The Grafoil material, is that the same CPEG that you have described in
`the Shane patent? A. (by counsel for Patent Owner): Yes.”
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`patent’s invention arises from a new use for this old composition. Redacted
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`PO Resp. 3 (“The invention of the ’520 Patent is using [CPEG] in a system
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`in such a way that heat is spread effectively” (emphasis added)); see Tr. 40,
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`ll. 1–5.6
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`Thus, the issue before us is whether the preponderance of the evidence
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`establishes that it would have been obvious to a person of ordinary skill in
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`the relevant technology, aware of the teachings of Shane as background
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`knowledge, to substitute the anisotropic CPEG/Grafoil graphite sheet, with
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`its known characteristics and properties, as disclosed in the Grafoil Manual,
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`for the anisotropic graphite sheet disclosed in Inoue.
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`Patent Owner argues that the CPEG sheet in the Grafoil Manual is
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`incompatible as a replacement for the carbonaceous sheet in Inoue.
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`Redacted PO Resp. 33. Patent Owner also argues that Inoue “dissuades,” or
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`teaches away from, using a Grafoil/CPEG sheet. Id. at 34.
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`According to Patent Owner, Inoue specifies that the carbonaceous
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`sheet “must” have a thermal conductivity that is one and a half to two and
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`half times that of copper and two and a half to four times that of aluminum.
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`Id. Patent Owner concludes that “[f]rom this, one of ordinary skill in the art
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`would realize that the ‘carbonaceous sheet’ must have an in-plane thermal
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`conductivity of at least 500 W/m·K.” Id. According to Patent Owner, these
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`are not “permissive” limitations, they are “mandatory” limitations. Tr. 44,
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`ll. 2–8. Patent Owner acknowledged, however, that Inoue did not state that
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`the limitations proposed by Patent Owner are “mandatory.” Tr. 44, ll. 21–22
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`6 “Q: . . . the material is old and that what you're claiming is that the claims
`are directed to a new use of an old material? A. (by counsel for Patent
`Owner): Yes . . . .”
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`(“The words ‘must’ are not in either paragraph 6 or paragraph 8 [of
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`Inoue].”). Counsel explained, however, that in paragraph 14 [of Inoue] “we
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`do see that such carbonaceous sheets have thermal conductivity higher than
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`that of copper or aluminum and can provide for highly efficient cooling. So
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`at a minimum, they must be higher than that of copper and aluminum.” Id.
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`at ll. 22–25.
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`Patent Owner asserts that “Inoue actually recommends types of
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`graphite different from that claimed in the ’520 Patent/CPEG.” Redacted
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`PO Resp. 23. Inoue discloses “the carbonaceous sheet is a sheet with
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`anisotropic thermal conductivity” and is “graphite with a high degree of
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`orientation.” Ex. 1016 ¶ 0013. Anisotropic thermal conductivity and a high
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`degree of orientation are the same characteristics attributed to the graphite
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`material in the claimed invention. See Ex. 1001, col. 4, ll. 1–9 (“[T]he
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`graphite material, as noted above, has also been found to possess a high
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`degree of anisotropy with respect to thermal conductivity . . . due to
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`orientation of the expanded graphite particles.”).
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`Patent Owner states that the particular type of graphite set forth in the
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`Grafoil Manual and claimed in the ’520 patent/CPEG, with an in-plane
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`thermal conductivity of only 140 W/m·K, would violate Inoue’s overt
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`mandate regarding threshold thermal condu