In Re: Cree, Inc. , 818 F.3d 694 ( 2016 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    IN RE: CREE, INC.,
    Appellant
    ______________________
    2015-1365
    ______________________
    Appeal from the United States Patent and Trademark
    Office, Patent Trial and Appeal Board in No. 90/010,940.
    ______________________
    Decided: March 21, 2016
    ______________________
    WILLIAM F. LEE, Wilmer Cutler Pickering Hale and
    Dorr LLP, Boston, MA, argued for appellant. Also repre-
    sented by SYDENHAM B. ALEXANDER, III, PETER M.
    DICHIARA, MARK CHRISTOPHER FLEMING, CYNTHIA D.
    VREELAND; BRITTANY BLUEITT AMADI, HEATHER M.
    PETRUZZI, Washington, DC.
    PHILIP J. WARRICK, Office of the Solicitor, United
    States Patent and Trademark Office, Alexandria, VA,
    argued for appellee Michelle K. Lee. Also represented by
    THOMAS W. KRAUSE, STACY BETH MARGOLIES, ROBERT J.
    MCMANUS.
    ______________________
    Before CHEN, CLEVENGER, and BRYSON, Circuit Judges.
    BRYSON, Circuit Judge.
    2                                           IN RE: CREE, INC.
    This is an appeal from a decision of the Patent Trial
    and Appeal Board in an ex parte reexamination proceed-
    ing. The Board held various claims of a patent owned by
    Cree, Inc., to be unpatentable as obvious. We affirm.
    I
    The patent in suit, Cree’s 
    U.S. Patent No. 6,600,175
    (“the ’175 patent”), filed in 1996, is entitled “Solid State
    White Light Emitter and Display Using Same.” The
    claims at issue in this appeal are directed to the produc-
    tion of white light through the “down-conversion” of blue
    light from light-emitting diodes (“LEDs”).            Down-
    conversion is the process in which high-energy (shorter
    wavelength) light is absorbed by a material and then re-
    emitted as lower energy (longer wavelength) light. By
    choosing the particular absorbing material, light at a
    desired wavelength (and thus a desired color) can be
    produced.
    The examiner rejected six claims added during reex-
    amination of the ’175 patent as obvious under multiple
    combinations of prior art references, including the combi-
    nation of 
    U.S. Patent No. 3,691,482
     (“Pinnow”), 
    U.S. Patent No. 3,819,974
     (“Stevenson”), and 
    U.S. Patent No. 5,578,839
     (“Nakamura”). The Board upheld the rejection
    based on that combination of references, among others.
    Claim 118, added during reexamination of the ’175
    patent, is representative of the six rejected claims. It
    recites:
    A light-emission device, comprising a single-die,
    two-lead gallium nitride based semiconductor blue
    light-emitting diode emitting radiation; and a re-
    cipient down-converting luminophoric medium for
    down-converting the radiation emitted by the
    light-emitting diode, to a polychromatic white
    light, wherein the luminophoric medium is dis-
    persed in a polymer that is on or about the single-
    IN RE: CREE, INC.                                         3
    die, two lead gallium nitride based semiconductor
    blue light-emitting diode.
    The patent defines the term “luminophoric medium”
    to mean “a material which in response to radiation emit-
    ted by the solid state device emits light in the white
    visible light spectrum by fluorescence and/or phosphores-
    cence.” In the context of lamps and other lighting appli-
    cations, luminophoric materials are called phosphors;
    such phosphors emit light through either fluorescence or
    phosphorescence. 1 Fluorescence and phosphorescence are
    examples of down-conversion. In both cases, the essential
    principle is that light of short wavelength, such as blue or
    ultraviolet light, is absorbed by a phosphor and later re-
    emitted in the form of light with a longer wavelength.
    Different phosphors emit light of different colors, and
    phosphors can be combined to produce a range of colors.
    Down-conversion has a long history as a source of
    light of various colors, including white light. For example,
    fluorescent lamps create white light by down-converting
    the ultraviolet light emitted by excited mercury gas.
    Fluorescent lamps are well known in the art and have
    been commercially available since the 1930s.
    1   In both phosphorescence and fluorescence, the
    luminescent material absorbs a photon that excites an
    electron. In fluorescence, the electron quickly (on the
    order of 10-9 seconds) returns to the ground state and
    emits a photon having a wavelength equal to or longer
    than that of the absorbed photon. Peter Pringsheim,
    Fluorescence and Phosphorescence 2-5 (1949). In phos-
    phorescence the process is much slower, and the light
    emission can occur long after absorption. That property
    accounts for glowing wristwatch hands and glow-in-the-
    dark toys that can emit light in a dark room.
    4                                          IN RE: CREE, INC.
    The ’175 patent recites the use of down-conversion to
    create white light with an LED. In one embodiment
    described in the ’175 patent, a blue LED commercially
    available from Nichia Chemical Industries, Ltd., is used
    with three commercially available phosphors—a blue
    phosphor (Lumogen® F Violet 570), a green-yellow phos-
    phor (Lumogen® F Yellow 083), and a red phosphor
    (Lumogen® F Red 300). The combination of those colors
    results in the production of light that is perceived as
    white.
    The Pinnow patent, published in 1972, discloses a
    display system that creates black and white images using
    a combination of a blue laser and appropriate phosphors.
    It also provides a detailed disclosure of the necessary
    conditions to create white light through the process of
    down-conversion.
    In particular, Pinnow teaches that a blue argon-ion
    laser can produce white light by down-conversion of short
    wavelength laser light to combinations of longer wave-
    length light emitted by various phosphors. Pinnow ex-
    plains that “a necessary condition for achieving a true
    white is that the illuminating laser beam have a wave-
    length of approximately 4,950 Å or shorter,” which is in
    the blue to violet range of the visible spectrum.
    The Stevenson patent, published in 1974, discloses a
    type of gallium nitride LED. Stevenson’s LED emits light
    in the violet region of the spectrum and “may be converted
    to lower frequencies (lower energy) with good conversion
    efficiency using organic and inorganic phosphors.” Ste-
    venson notes that with the “use of different phosphors, all
    the primary colors may be developed from this same basic
    device.”
    Finally, the Nakamura patent, which was published
    in Japan in 1993, discloses a gallium nitride LED that
    emits blue light. The Nakamura LED was much brighter
    than other similar LEDs previously developed, and it was
    IN RE: CREE, INC.                                         5
    widely recognized as a major breakthrough, earning Dr.
    Nakamura the 2014 Nobel Prize in Physics.
    Based on those references, the examiner found that
    “[i]t would have been obvious to one of ordinary skill in
    the art, at the time of the invention to substitute Steven-
    son’s GaN-based LED with either the known UV light
    emitting or blue light emitting GaN-based LED disclosed
    in Nakamura.” The examiner further found that the
    combination was a “simple substitution of one known
    element (Nakamura’s GaN-based LED) for another
    known element (Stevenson’s GaN-based LED) to obtain
    predictable results.” The examiner explained that the
    reason to combine the references was the “advantage or
    expected beneficial result” that would result from replac-
    ing Stevenson’s LED with the more powerful Nakamura
    LED. The examiner concluded that, because Nakamura’s
    LED “would provide more photons to be down-converted
    by the phosphors and thereby provide brighter overall
    light emission from the device,” the advantage of brighter
    emission by the phosphors would be readily apparent to a
    person of ordinary skill in the art.
    The Board upheld the examiner’s rejection in view of
    the combination of Pinnow, Stevenson, and Nakamura.
    The Board agreed with the examiner’s reasoning, incorpo-
    rating 109 pages of the examiner’s answer into its own
    opinion. 2 In summarizing the grounds for its decision, the
    Board stated:
    2   Cree suggests that it was improper under the
    Administrative Procedure Act for the Board to incorporate
    substantial portions of the Examiner’s Answer into its
    opinion. There is no force to that argument. It is com-
    monplace in administrative law for a reviewing body
    within an agency to adopt a fact-finding body’s findings.
    On judicial review, the adopted material is treated as if it
    6                                          IN RE: CREE, INC.
    (1) Stevenson and Nakamura teach a two-lead,
    GaN-based blue LED on a single die, (2) Steven-
    son and Pinnow teach a “down-conversion” via
    phosphors from LED light, including phosphors
    dispersed in a polymer located “about” the LED
    (Ans. 117-121) and, given the presumed
    knowledge by an artisan of ordinary skill regard-
    ing the relevant prior art at the time of Appel-
    lant’s invention, (3) the combined teachings of
    Stevenson, Pinnow, and Nakamura would have
    were part of the reviewing body’s opinion. See, e.g., DHL
    Express, Inc. v. NLRB, Nos. 12-1072, -1143, 
    2016 WL 278075
    , at *8 (D.C. Cir. Jan. 21, 2016); Sanchez-Robles v.
    Lynch, 
    808 F.3d 688
    , 692 (6th Cir. 2015); Mike-Sell’s
    Potato Chip Co. v. NLRB, 
    807 F.3d 318
    , 321 (D.C. Cir.
    2015).
    This court does the same in the case of Board opinions
    adopting patent examiners’ findings. See In re Brana, 
    51 F.3d 1560
    , 1564 n.13 (Fed. Cir. 1995) (“The Board’s deci-
    sion did not expressly make any independent factual
    determinations or legal conclusions. Rather, the Board
    stated that it ‘agree[d] with the examiner’s well reasoned,
    well stated and fully supported by citation of relevant
    precedent position in every particular, and any further
    comment which we might add would be redundant.’
    Therefore, reference in this opinion to Board findings are
    actually arguments made by the examiner which have
    been expressly adopted by the Board.”) (internal citations
    omitted).
    Contrary to Cree’s suggestion, this court in In re Lee,
    
    277 F.3d 1338
     (Fed. Cir. 2002), did not vacate the Board’s
    decision on the ground that the Board adopted some
    portions of the examiner’s answer as its own opinion.
    Instead, we vacated the Board’s decision because “neither
    the examiner nor the Board adequately supported” the
    rejection.
    IN RE: CREE, INC.                                         7
    suggested to an artisan of ordinary skill to use a
    blue LED on a single die to create white light via
    “down-conversion” because Nakamura’s blue LED
    is more powerful than Stevenson’s older, less-
    efficient LED in terms of power and brightness
    and, as such, is more suitable with a “down-
    conversion” process to produce white light.
    In the Board’s view the invention was “nothing more
    than a new application of a high-power, high-brightness
    blue LED developed by Dr. Nakamura in late 1993.” The
    Board found that the new application was predictable in
    view of the state of the art in LEDs, the market demand
    for white light devices, the finite number of identified
    means to convert light from LEDs into white light, and
    the advantages of using the down-conversion approach.
    II
    A
    On appeal, Cree first argues that the Board erred by
    assuming that it was known in the prior art to make
    white light from a monochromatic LED through down-
    conversion. In Cree’s view, “[t]he Board ruled that it was
    obvious to use down-conversion to create white light from
    LEDs because it was (according to the Board) not merely
    obvious, but actually already known.” Cree bases this
    argument on a passage from the Board’s opinion in which
    the Board stated the following:
    Appellant’s experts, Drs. Stringfellow, Redwing,
    and Wetzel, acknowledge: (1) Stevenson’s seminal
    work on a violet/blue LED in early 1974, and (2)
    at the time of Appellant’s invention in early 1996,
    there were two known approaches to produce
    white light from LEDs. One was a direct-emission
    “triplet” approach in which individual LEDs that
    emit three primary colors—red, green, and blue
    (RGB)—are packaged together and then all the
    8                                            IN RE: CREE, INC.
    primary (RGB) colors are mixed together to form
    white light. The other was a “down-conversion”
    approach in which a phosphor material is used to
    convert monochromatic light from a blue or ultra-
    violet (UV) LED to create white light, much in the
    same way a fluorescent light bulb works.
    Cree infers that the Board’s use of the word “known”
    in that passage indicates that the Board erroneously
    concluded that a single reference disclosed down-
    conversion from blue LED light to white light. We do not
    read the Board’s use of the term “known” in that fashion.
    The Board’s opinion makes clear that the Board fo-
    cused on the general disclosure of the process of down-
    conversion, rather than any disclosure of down-conversion
    limited to a particular source, i.e., an LED. The Board
    explained that Pinnow discloses “a ‘down-conversion’
    approach to create white light,” and that nothing in
    Pinnow suggests that the particular source of primary
    radiation is important to the down-conversion process.
    The examiner noted that Pinnow discusses down-
    conversion generally, not the specific down-conversion of
    blue LED light to white light. The examiner character-
    ized the source of the primary radiation as unimportant
    “because it is the wavelength of the source that matters
    not the source itself.” In the portion of his answer that
    the Board adopted, the examiner stated that a person of
    ordinary skill in the art “is not going to fail to appreciate
    the other teachings in Pinnow simply because a laser is
    used as the primary light source, because the phosphors
    cannot tell from what light source a wavelength of light
    comes. Rather, they can only absorb or not absorb a given
    wavelength.” The examiner also stated that “it does not
    matter that Pinnow uses a laser, it only enhances the
    point that a [person having ordinary skill in the art] is
    aware of a variety of UV to blue radiation sources that are
    capable of being used to produce light of various colors,
    IN RE: CREE, INC.                                           9
    including white, by down-converting the primary radia-
    tion to longer-wavelength visible light using a mixture of
    phosphors in a single medium.”
    In context, it is clear that the Board was not using the
    word “known” to mean “disclosed in a single reference.”
    Instead, the Board’s statement that down-conversion was
    a known approach for creating white light from an LED is
    best understood to mean that persons of skill in the art
    were aware that down-conversion could be used to make
    white light out of blue light, regardless of the source of the
    light.
    The Board found that Pinnow teaches a down-
    conversion process for creating white light that would
    work with blue light of any source, including the blue
    LEDs disclosed in Nakamura. That was an entirely
    reasonable conclusion to draw from Pinnow. Therefore
    the Board was correct when it said that it was “known” to
    create white light from LEDs using down-conversion, as
    Pinnow teaches a down-conversion process that was
    understood to be equally applicable when used with an
    LED light source as with the laser source specifically used
    in Pinnow.
    B
    Cree next argues that the Board reached its conclu-
    sion that down-conversion was “known” by misreading the
    declarations of Cree’s experts, Drs. Stringfellow, Redwing,
    and Wetzel. We agree with the Board that Cree’s experts
    testified that down-conversion from blue LED to white
    light was a known, but disfavored, option prior to the
    availability of high intensity blue LEDs such as Nakamu-
    ra’s. Dr. Wetzel stated that “[d]own conversion of LED
    light had been considered, but was discredited due to the
    loss of energy and light brightness during the down-
    conversion process.” He then went on to explain why
    persons in the art would prefer to generate white light by
    mixing the output of three primary colored LEDs in a
    10                                          IN RE: CREE, INC.
    triplet format. In saying that down-conversion was a
    discredited solution to the problem of generating white
    light from LEDs, Dr. Wetzel in effect acknowledged that
    down-conversion of LED light was at least known to those
    in the art. Thus, Dr. Wetzel’s testimony cuts against
    Cree’s contention that generating white light from blue
    LEDs was unknown.
    Dr. Redwing stated in her declaration that “down
    conversion of LED light was known and had been used in
    very select and rare occasions.” She added, however, that
    down-conversion would not be used as a practical source
    of white light, because white light applications would
    have “required a significant amount of power and bright-
    ness,” and “[l]ow illumination, as might be the case for an
    indicator light or a calculator, would clearly be insuffi-
    cient for white light in these applications.”
    Dr. Redwing’s statement addressed the question
    whether, before the Nakamura LED, a person of skill in
    the art would reject the down-conversion approach for
    practical applications. As in the case of Dr. Wetzel,
    however, her discussion of the competing technologies
    clearly reveals that down-conversion was a known method
    of creating white light prior to the ’175 patent. We there-
    fore reject Cree’s suggestion that it was error for the
    Board to cite Dr. Redwing’s testimony as support for its
    finding that down-conversion to create white light from
    LEDs was a known option prior to the ’175 patent.
    Finally, Dr. Stringfellow stated that at the time of the
    ’175 patent, “the industry was focused on LEDs that
    directly emitted the color of interest and there was no
    focus on the use of down-conversion because (a) it would
    waste energy; (b) it was no longer needed to create prima-
    ry colors; and (c) it entailed increased cost and complexi-
    ty.” Again, his testimony simply establishes that the use
    of down-conversion was not a preferred option for practi-
    cal reasons. It does not show that down-conversion from
    IN RE: CREE, INC.                                       11
    LEDs was unknown or could not have practical applica-
    tions if a sufficiently powerful LED were available (such
    as the one invented by Nakamura). Because it was rea-
    sonable for the Board to draw the conclusion from Dr.
    Stringfellow’s testimony that down-conversion was a
    known solution for generating white light from a blue
    LED, the Board’s decision is supported by substantial
    evidence. See In re Jolley, 
    308 F.3d 1317
    , 1329 (Fed. Cir.
    2002) (“[W]here two different, inconsistent conclusions
    may reasonably be drawn from the evidence in record, an
    agency’s decision to favor one conclusion over the other is
    the epitome of a decision that must be sustained upon
    review for substantial evidence.”).
    C
    Cree next takes issue with the Board’s analysis of the
    motivation to combine. In particular, Cree argues that
    “neither the Examiner nor the Board articulated any
    rational motivation for why a skilled artisan would have
    combined the teachings of Pinnow—which discloses the
    projection of a large, high-powered, gas laser beam
    through a modulator and a deflector and onto a phosphor
    screen to display a white image—with the teachings of
    Stevenson and Nakamura, which disclose violet and blue
    LEDs.”
    Contrary to Cree’s contention, the Board provided a
    sufficient, non-hindsight reason to combine the refer-
    ences. The Board found that a person of ordinary skill in
    the art would realize that Nakamura (a brighter LED)
    would be an upgrade over the LED of Stevenson for use
    with down-conversion and that the Nakamura LED would
    therefore be suitable to produce white light based on the
    teachings of Pinnow. The availability of the high-powered
    Nakamura LED thus provided the motivation to combine
    Stevenson’s use of LEDs to create primary colors with
    Pinnow’s use of a short-wavelength light source to create
    white light.
    12                                          IN RE: CREE, INC.
    Cree’s quarrels with the Board’s analysis of the moti-
    vation to combine are without merit. Cree argues that
    because a laser generates more output power than an
    LED, a person of ordinary skill would fail to appreciate
    that Pinnow’s teachings on down-conversion would be
    applicable to LEDs as well. However, the examiner
    pointed to ample evidence that Pinnow’s teachings are
    applicable to LEDs. In a portion of the examiner’s answer
    adopted by the Board, the examiner explained that “the
    phosphors’ ability to convert the UV-to-blue light is predi-
    cated only on whether or not it can absorb a given wave-
    length of light, not on which kind of light source a
    particular wavelength of light is emitted, laser, LED, or
    otherwise, as a [person of ordinary skill in the art] would
    readily appreciate.” In other words, a phosphor does not
    care how an incident photon of light at a particular wave-
    length was generated.
    Cree also argues that color mixing and phosphor se-
    lection are more difficult when using a source with a
    broader emission spectrum, such as an LED, than one
    with a narrower emission spectrum, such as a laser. The
    examiner (in a portion of his answer adopted by the
    Board) also addressed that issue: He stated that “the
    issue of phosphor selection for UV-to-blue radiation was
    successfully addressed in the 1930’s. While the exact
    same phosphor mixture as used in fluorescent bulbs
    might not be used with a GaN-based LED of Stevenson or
    Nakamura, it certainly is factual evidence that those of
    skill in the art have sufficient understanding of the scien-
    tific and engineering principles to choose phosphors for a
    broadband, UV-to-blue primary radiation source.” The
    examiner and the Board thus based the rejection on
    IN RE: CREE, INC.                                        13
    sufficient evidence that a person of ordinary skill in the
    art would have had a reason to combine the references. 3
    III
    Cree’s final argument is that the Board improperly re-
    jected Cree’s proffered secondary evidence of non-
    obviousness. Cree points to three categories of secondary
    evidence that, according to Cree, the Board improperly
    discounted: evidence of industry praise; evidence of licens-
    ing; and evidence of the commercial success of white LED
    3   Cree argues that the Board’s rejection was based
    on “impermissible hindsight.” That argument, however,
    is essentially a repackaging of the argument that there
    was insufficient evidence of a motivation to combine the
    references. It is fully answered by the Board’s observa-
    tion that “the weight of the evidence shows that the
    proffered combination is merely a predictable use of prior
    art elements according to their established functions.”
    Cree also asserts that the Board improperly shifted
    the burden to Cree to show that the claims at issue would
    not have been obvious. That argument, too, lacks merit.
    The Board stated that the examiner had provided “a
    reason showing motivation by a person of ordinary skill in
    the art to achieve the claimed subject matter.” Immedi-
    ately thereafter, in the passage quoted by Cree, the Board
    stated that Cree “has not demonstrated why that reason
    is erroneous or why a person of ordinary skill in the art
    would not have reached the conclusions reached by the
    Examiner” (emphasis in original). In context, it is clear
    that the sentence quoted by Cree simply states that Cree
    failed to show why the examiner’s finding was incorrect.
    In short, the Board held that the examiner carried his
    burden on the issue of obviousness, and Cree failed to
    offer any convincing reason to find otherwise. That is not
    burden-shifting. See Belden, Inc. v. Berk-Tek LLC, 610 F.
    App’x 997, 1004-05 (Fed. Cir. 2015).
    14                                          IN RE: CREE, INC.
    products. The Board analyzed each of the claimed sec-
    ondary considerations and concluded that the evidence of
    secondary considerations “does not outweigh the strong
    evidence of obviousness.”
    A
    Cree first points to two press releases from the
    Fraunhoffer Institute and contends that those press
    releases support the inference of non-obviousness. The
    press releases describe the down-conversion of blue LED
    light to produce white light as a “breakthrough” and an
    “innovative idea.” The Board, however, found the press
    releases unpersuasive as secondary evidence, because the
    praise was directed to the Fraunhoffer Institute’s own
    work, not the work of the inventors of the ’175 patent.
    Cree faults the Board for discounting that evidence.
    In Cree’s view, even though the press releases were
    directed to the work of others, the praise for the concept
    still had the requisite nexus to the claimed invention.
    We agree with the Board’s treatment of this evidence.
    While “praise in the industry for a patented invention,
    and specifically praise from a competitor tends to ‘indicate
    that the invention was not obvious,’” self-serving state-
    ments from researchers about their own work do not have
    the same reliability. Power-One v. Artesyn Techs., Inc.,
    
    599 F.3d 1343
    , 1352 (Fed. Cir. 2010) (quoting Allen Ar-
    chery, Inc. v. Browning Mfg. Co., 
    819 F.2d 1087
    , 1092
    (Fed. Cir. 1987)). The Board thus permissibly concluded
    that the press releases were unpersuasive and, if any-
    thing, showed that down-conversion was the logical next
    step after the development of the Nakamura LED.
    B
    Cree next points to evidence of licensing. During the
    reexamination proceedings, Cree put forward declaration
    testimony and press releases describing certain licensing
    transactions. The Board found the evidence of licensing
    IN RE: CREE, INC.                                            15
    unpersuasive for failing to show a sufficient nexus to the
    ’175 patent.
    Our cases “specifically require affirmative evidence of
    nexus where the evidence of commercial success present-
    ed is a license, because it is often ‘cheaper to take licenses
    than to defend infringement suits.’” Iron Grip Barbell Co.
    v. USA Sports, Inc., 
    392 F.3d 1317
    , 1324 (Fed. Cir. 2004)
    (quoting EWP Corp. v. Reliance Universal Inc., 
    755 F.2d 898
    , 908 (Fed. Cir. 1985)). When the specific licenses are
    not in the record, it is difficult for the court to determine if
    “the licensing program was successful either because of
    the merits of the claimed invention or because they were
    entered into as business decisions to avoid litigation,
    because of prior business relationships, or for other eco-
    nomic reasons.” In re Antor Media Corp., 
    689 F.3d 1282
    ,
    1294 (Fed. Cir. 2012). That is the situation here. Cree
    has provided press releases evidencing that it has entered
    into licensing transactions, but has not shown that the
    licenses were based on the merits of the ’175 patent.
    Additionally, the press releases indicate that some of
    the licenses were broad cross-licenses (such as the licens-
    es to Nichia, Toyoda Gosei, Osram, and Phillips) or were
    intended to resolve litigation (such as the license to
    Nichia). Some of the press releases on which Cree relies
    define the scope of the licensing transactions as “broad
    and substantial,” “comprehensive [and] worldwide,” and
    “cover[ing] patents from both parties in the fields of blue
    LED chip technology, white LEDs and phosphors (includ-
    ing remote phosphors), control systems, LED luminaries
    and lamps as well as LED backlighting of liquid crystal
    displays (LCDs) and patents in Phillips LED Luminaire
    Licensing Program.” In light of the lack of specificity in
    that evidence, it was reasonable for the Board to find that
    the licenses were not shown to have a sufficient nexus to
    the ’175 patent to require a finding of non-obviousness.
    16                                         IN RE: CREE, INC.
    C
    The final piece of secondary evidence on which Cree
    relies is evidence of commercial success. Cree put forward
    evidence in the form of a declaration by Dr. Brandes, who
    presented sales figures showing the growth of the white
    LED market and stated that in his opinion there is a
    nexus between the sales figures and the ’175 patent. The
    Board found that “Dr. Brandes’ declaration [did] not show
    a correlation between the claimed invention and the sales
    numbers,” and that his characterization of a nexus “is
    nothing more than an allegation or a conclusory state-
    ment.”
    When commercial success is cited as a basis for infer-
    ring non-obviousness, a nexus must be shown between the
    commercial success and the claimed features of the pa-
    tent. In re Huang, 
    100 F.3d 135
    , 139-40 (Fed. Cir. 1996).
    We agree with the Board that Dr. Brandes’ declara-
    tion merely repeats, in conclusory fashion, that there is a
    nexus between the success of white LEDs and the claimed
    invention. The Board found that the evidence showed
    sales of white light products using LEDs with lumino-
    phoric substances, such as consumer products incorporat-
    ing white LED backlit LCD displays, but that there was
    no sufficient showing of a nexus between those sales and
    the invention.
    In a portion of the examiner’s answer that was adopt-
    ed by the Board, the examiner found that the commercial
    success of white LEDs “cannot be due to simply making a
    single-die semiconductor LED that emits white light,”
    because if that were so, “then the commercialization could
    have started back in 1973.” Instead, the examiner found,
    “it appears that Wetzel, Redwing, and Stringfellow all
    acknowledge the invention of a GaN LED with sufficiently
    high light output, somewhere in the UV to blue region of
    the spectrum was the thing that made the down-
    IN RE: CREE, INC.                                        17
    converting device of Stevenson . . . commercial[ly] success-
    ful.”
    Cree has failed to rebut the Board’s finding of a lack
    of nexus between the invention and the commercial
    success of white light LEDs. As the Board found, “the
    record is completely silent on whether the commercial
    success was caused by the subject matter of the ’175
    patent as distinct from the prior art.” For that reason, we
    sustain the Board’s conclusion that the evidence of com-
    mercial success did not outweigh the strong prima facie
    showing of obviousness.
    We therefore uphold the Board’s decision rejecting the
    disputed claims of the ’175 patent.
    AFFIRMED