Ex Parte Clovesko et al

Board of Patent Appeals and Interferences

Jan 6, 2012

11590061 (B.P.A.I. Jan. 6, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte TIMOTHY CLOVESKO, JULIAN NORLEY,
MARTIN DAVID SMALC, and JOSEPH PAUL CAPP
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Appeal 2011-001666
Application 11/590,061
Technology Center 1700
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Before EDWARD C. KIMLIN, BRADLEY R. GARRIS, and
CATHERINE Q. TIMM, Administrative Patent Judges.

KIMLIN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal from the final rejection of claims 1, 2, 5, 6, and 11-
15. We have jurisdiction under 35 U.S.C. § 6(b).
Claim 1 is illustrative:
1. A display device, comprising a display panel, a plurality of heat
sources, and a heat spreader dimensioned so as to be at least about 270
millimeters x 500 millimeters, and which comprises at least one sheet of
compressed particles of exfoliated graphite having two major surfaces, the
heat spreader having a thickness of no greater than about 2 mm, wherein the
at least one sheet of compressed particles of exfoliated graphite is
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anisotropic and has a surface area larger than the surface area of one of the
heat sources, and wherein one of the major surfaces of the heat spreader has
an adhesive thereon to permit substantially all of such major surface to be in
thermal contact with the plurality of heat sources in the display device, and
further wherein the heat spreader has a density of from about 1.6 g/cc to
about 1.9 g/cc and comprises a backing layer to improve handling and/or
reduce damage during shipment or application to the panel, without
compromising the thermal spreading capabilities of the heat spreader.

The Examiner relies upon the following references as evidence of
obviousness (Ans. 3):
Harris 5,748,269 May 05, 1998
Morita 5,831,374 Nov. 03, 1998
Tzeng ‘400 6,245,400 B1 Jun. 12, 2001
Tzeng ‘520 6,482,520 B1 Nov. 19, 2002
Khatri 6,610,635 B2 Aug. 26, 2003

Appellants’ claimed invention is directed to a display device
comprising, inter alia, a heat spreader comprising at least one sheet of
compressed particles of exfoliated graphite having the recited dimensions.
The appealed claims stand rejected under 35 U.S.C. § 103(a) as
follows:
(a) claims 1, 2, 5, and 6 over Morita in view of Tzeng ‘520, and
(b) claims 11-15 over Morita in view of Tzeng ‘520 further in view of
Khatri, Harris and Tzeng ‘400.
We have thoroughly reviewed each of Appellants’ arguments for
patentability as well as the declaration evidence relied upon in support
thereof. However, we are in complete agreement with the Examiner that the
claimed subject matter would have been obvious to one of ordinary skill in
the art within the meaning of § 103 in view of the applied prior art.
Accordingly, we will sustain the Examiner’s rejections for essentially those
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reasons expressed in the Answer, and we add the following primarily for
emphasis.
There is no dispute that Morita, like Appellants, teaches a plasma
display device comprising an anisotropic graphite heat equalizing layer for
transferring heat to a heat sinking unit. As recognized by the Examiner,
Morita does not disclose that the graphite layer comprises exfoliated
graphite, as presently claimed. However, Tzeng ‘520 discloses an
anisotropic exfoliated graphite material that is used as a heat spreader to
manage the heat from a heat source of an electronic component.
Accordingly, we agree with the Examiner that it would have been obvious
for one of ordinary skill in the art to use the exfoliated graphite of Tzeng
‘520 as the graphite heat spreader of Morita due to its anisotropic properties
and conformability, properties desired by Morita.
Appellants contend, with the support of the Reis Declaration, that the
pyrolytic graphite material of Morita cannot function as a heat spreader in
the Morita display panel “since the material cannot be made in dimensions
and having characteristics needed for effective plasma display panel heat
spreading applications” (App. Br. 13, first para.). This argument, however,
misses the thrust of the Examiner’s rejection which cites Tzeng ‘520 for
evidence that it would have been obvious for one of ordinary skill in the art
to use exfoliated graphite material as the heat equalizing layer 6 of Morita.
Appellants have not refuted the Examiner’s statement that Tzeng ‘520
“teaches expanded or exfoliated natural graphite identical to the material
used in the instant invention” which would function like Appellants’
material (Ans. 11, first para.). We note that the Reis Declaration offers no
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opinion regarding the obviousness of using the exfoliated carbon material of
Tzeng ‘520 in the display device of Morita.
We are also not persuaded by Appellants’ argument that the skilled
artisan would recognize that the Morita pyrolytic graphite “functions as a
thermal interface, passing heat directly through its thickness, rather than a
heat spreader” (App. Br. 14, first para.). Indeed, Morita expressly discloses
that “[i]n the third embodiment, since the graphite film 6 is formed on the
panel unit back surface 11, heat locally generated in the panel unit 1 is
quickly transferred in lateral directions along the plane to raise the
temperature of non-activated portions of the panel unit 1” (col. 10, ll. 48-52,
emphasis added). Hence, it can be seen that the heat equalizing layer 6 of
Morita transfers heat in all directions and, therefore, we find no merit in
Appellants’ argument that Morita’s “material is a thermal interface, used to
pass heat through its thickness, and would be singularly unavailing as a heat
spreader for an emissive display device” (App. Br. 16, second para.). Also,
we observe that Appellants’ exfoliated graphite also provides a thermal
interface (see Tzeng ‘520, abstract). In addition, by Appellants’ own
argument that “[a] heat spreader seeks to spread heat laterally, along its
surface” (App. Br. 19, last para.), Morita’s graphite film 6, which transfers
heat in lateral directions, qualifies as a heat spreader. As pointed out by the
Examiner, Appellants’ Specification has not defined the claimed “heat
spreader” in any way which would distinguish it over the graphite film of
Morita, especially upon substitution of the exfoliated graphite of Tzeng
‘520.
Concerning separately rejected claims 11-15, which are directed to
properties of the adhesive on the heat spreader, we agree with the Examiner
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that, based on Tzeng ‘400 and Khatri, it would have been obvious to one of
ordinary skill in the art to provide a pressure sensitive adhesive on the heat
spreader of Morita in a manner that provides low thermal resistance, and to
resort to routine experimentation to determine the appropriate values of the
adhesive properties, such as lap shear adhesion strength and thickness.
Appellants have proffered no evidence of criticality with respect to the
claimed adhesive properties.
In conclusion, based on the foregoing and the reasons well stated by
the Examiner, the Examiner’s decision rejecting the appealed claims is
affirmed.

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. §1.136(a)(1)(v).
AFFIRMED

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