Ex Parte Speit et al

Patent Trial and Appeal Board

Aug 12, 2016

12775912 (P.T.A.B. Aug. 12, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
121775,912 05/07/2010
278 7590 08/16/2016
MICHAEL J, STRIKER
103 EAST NECK ROAD
HUNTINGTON, NY 11743
FIRST NAMED INVENTOR
Burkhard Speit
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
4876 1117
EXAMINER
PILLAY, DEVINA
ART UNIT PAPER NUMBER
1755
NOTIFICATION DATE DELIVERY MODE
08/16/2016 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
striker@strikerlaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte BURKHARD SPEIT, EVELINE RUDIGIER-VOIGT,
WOLFGANG MANNSTADT, and SILKE WOLFF
Appeal 2016-006428
Application 12/775,912
Technology Center 1700
Before PETER F. KRATZ, LINDA M. GAUDETTE, and DEBRA L. DENNETT,
Administrative Patent Judges.
GAUDETTE, Administrative Patent Judge.
DECISION ON APPEAL
Appeal 2016-006428
Application 12/775,912
Appellants 1 appeal under 35 U.S.C. § 134(a) from the Examiner's decision2
finally rejecting claims 30, 33-36, 38, 39, 41, and 42 rejected under pre-AIA 35
U.S.C. § 103(a) as unpatentable over Buller (US 2007/0215197 Al, published
Sept. 20, 2007) in view of Speit (US 5,895,768, issued Apr. 20, 1999), Kurachi et
al., (US 2005/0003136 Al, published Jan. 6, 2005), Lu (US 2008/0308147 Al,
published Dec. 18, 2008), and Dhere (US 2007 /0257255 Al, published Nov. 8,
2007). We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
The invention relates to a thin-film solar cell with improved efficiency.
Specification filed May 7, 2010 ("Spec."), 1, The Field of the Invention; 4:3-5. At
the time of the invention, soda-lime float glasses, as well as other glass types, were
considered suitable for thin-film photovoltaic applications. Id. at 2: 18-21.
According to the Specification, the inventive thin-film solar cell, which utilizes an
aluminosilicate glass substrate having a specific composition and properties, was
found to have more than 15% higher efficiency as compared to a solar cell on a
conventional soda-lime glass substrate. Spec. 15:21-16:4, 17:5-8. Claim 30, the
sole independent claim on appeal, is representative of the invention and is
reproduced below:
30. A thin-film solar cell having an improved efficiency, said thin-film
solar cell comprising
a Na20-containing multi-component substrate glass,
1 Appellants identify the real party in interest as Schott AG. Appeal Brief filed
November 9, 2015 ("App. Br."), 3.
2 Final Office Action mailed July 29, 2015 ("Final Act.").
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Appeal 2016-006428
Application 12/775,912
a molybdenum layer on said Na20-containing multicomponent
substrate glass, said molybdenum layer having a thickness from 0.25 to 3.0
µm, and
a CIGS semiconductor layer on a side of said molybdenum layer
opposite from said substrate glass, so that said molybdenum layer is between
said at least one semiconductor layer and said substrate glass;
so that sodium ions from the substrate glass are incorporated as
dopants in said at least one semiconductor layer by diffusion through the
molybdenum layer and/or vaporization and thus solar cell efficiency for
conversion of solar energy into electric power is improved as a result of said
incorporation of said sodium ions into said semiconductor layer;
wherein said substrate glass has a glass transition temperature
Tg of greater than 550°C, and a coefficient of thermal expansion a201300 from
7.5 x 10-6 /K to 9.5 x 10-6 /Kin a temperature range from 20°C to
300°C·
'
wherein said substrate glass is free of B203, is free of BaO, and
has a composition, in Mol %, comprising:
Si02
Ab03
Na20
K20
MgO
CaO+SrO+ZnO
Ti02+Zr02
Ce02
As203+Sb203
3
63---67 .5
10-12.5
8.5-15.82
2.5--4.0
3.0-9.0
0-2
0.5-1.5
0.02---0.5
0---0.4
Appeal 2016-006428
Application 12/775,912
F
0-1.5
0.05-2.6;
wherein components of the substrate glass are present in the glass in
the following molar ratios:
Si02/Ah03
Na20/K20
AhOiK20
A1203/Na20
(Na20+K20)/(MgO+CaO+SrO)
5.0 - 6.8
2.1 - 6.2
2.5 - 5.0
0.6 - 1.5
0.95- 6.5.
The Examiner finds "Buller discloses a thin film solar cell comprising an
aluminosilicate glass substrate, ... a molybdenum layer on the aluminosilicate
glass substrate, and a semiconductor layer comprising CIGS on the molybdenum
layer." Ans. 2 (internal citations omitted). The Examiner acknowledges Buller
does not disclose the claimed thickness of the molybdenum layer, but finds it
would have been obvious to have used a thickness in the claimed range based on
Dhere' s disclosure of using a back electrode layer of molybdenum having a
thickness of 0.02-1 micron. Id. at 7; Dhere i-f 26. The Examiner also
acknowledges Buller does not disclose an aluminosilicate glass having the
composition recited in claim 30, but finds Speit discloses an "aluminosilicate glass
used as a substrate for a semiconductor device which has high flexural strength and
high quality" and includes the same components as the aluminosilicate glass
recited in claim 30, in amounts that overlap those recited in claim 30. Ans. 2-5.
The Examiner finds one of ordinary skill in the art would have been motivated "to
modify the aluminosilicate glass substrate of Buller by using the aluminosilicate
glass of Speit because it has high flexural strength and high quality." Id. at 4. The
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Appeal 2016-006428
Application 12/775,912
Examiner relies on Lu for a teaching that migration of Na from a glass substrate
into a CIS or CIGS photovoltaic layer improves the performance of the device, and
that Na has been found to migrate through a molybdenum electrode. Id. at 5
(citing Lu ,-r 52). The Examiner relies on Kurachi for a teaching that BaO inhibits
an alkali from migrating in the glass, and that barium raw material is a poisonous
substance making it difficult to handle. Id.; see Kurachi i-f 79. The Examiner finds
one of ordinary skill in the art would have been motivated to eliminate BaO in the
glass substrate of Buller as modified by Speit based on Lu's and Kurachi's
teachings because the ordinary artisan would understand from Lu that Na
migration into the semiconductor layer is desirable and would be inhibited by BaO,
as taught by Kurachi. Ans. 5. The Examiner further finds one of ordinary skill in
the art would have been motivated to make this modification to eliminate the need
to handle barium (a poisonous material as taught by Kurachi), thereby easing the
manufacturing process. Id.
The Examiner's fact finding and reasoning, as set forth in the Final Office
Action, Advisory Action (mailed October 8, 2015), and Answer, support the
Examiner's conclusion of obviousness as to appealed claims 30, 33-36, 38, 39, 41
and 42 by a preponderance of the evidence. See Final Act. 3-9; Advisory Action
1-2; Ans. 2-8. We have considered the arguments advanced by Appellants in the
Appeal Brief, including those arguments asserting evidence of unexpected results
(see App. Br. 27-30), and determine these arguments have been fully addressed by
the Examiner in the Response to Argument section of the Answer, and are
unpersuasive of reversible error in the Examiner's conclusion of obviousness for
the reasons stated therein. See Ans. 8-13. We add the following comments for
emphasis.
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Appeal 2016-006428
Application 12/775,912
Appellants argue the ordinary artisan would not have had a reason to select
Speit's almninosilicate glass for use as Buller's solar cell substrate rather than one
of Buller' s substrate materials (such as plastics or metals or other classes of glass),
many of which also have high flexural strengths. App. Br. 17.
An obviousness rejection predicated on selection of one or more components
may be appropriate if the prior art provides direction as to which choice is likely to
be successful. See PharmaStem Therapeutics, Inc. v. ViaCell, Inc., 491 F.3d
1342, 1364 (Fed. Cir. 2007); In re O'Farrell, 853 F.2d 894, 903 (Fed. Cir. 1988);
see also Merck & Co., Inc. v. Biocraft Labs., Inc., 874 F.2d 804, 807 (Fed. Cir.
1989) ("That the '813 patent discloses a multitude of effective combinations does
not render any particular formulation less obvious.").
Buller discloses, very generally, that the substrate may be made of a plastic,
metal, metal alloy, or glass. See, e.g., Buller i-fi-124, 103. Buller also provides
specific direction that aluminosilicate glass is a material likely to be used
successfully as a substrate in Buller's solar cell. See, e.g., id. i-fi-124, 36, and 109;
claim 9. Appellants' arguments fail to identify reversible error in the Examiner's
findings (see Ans. 8-9) that the ordinary artisan, when selecting an aluminosilicate
glass as the substrate for Buller' s solar cell, would have understood the importance
of a defect free, high flexural strength substrate, and been motivated to select
Speit's aluminosilicate glass which Speit describes as having these properties (see
Speit2:53-57). See In re Fox, 471F.2d1405, 1407 (CCPA 1973) andin re
Kunzmann, 326 F.2d 424, 425 n.3 (CCPA 1964) (noting that an Examiner's
statement is accepted as true when an appellant fails to question its accuracy or to
present contradicting evidence).
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Application 12/775,912
Appellants argue "[t]he glass compositions of Kurachi do not exclude BaO
from all embodiments of their glass product. Their glass compositions can have up
to 1 % BaO." App. Br. 22.
Appellants' argument ignores Kurachi's statement clearly expressing a
preference for a BaO-free glass composition. Kurachi ,-r 79 ("BaO ... more
preferably is substantially an impurity amount."); cf Spec. 7:3-5 (defining "free of
... BaO" as allowing for the presence of "unavoidable traces"). Moreover,
Appellants' Specification does not support their assertions that "1 % BaO is not
'small' or 'negligible"' and "smaller amounts of about 0.1 % or even less ... [can]
significantly affect the properties of the glass" (App. Br. 23). See Spec. 4:6-10
("The Na20-containing multicomponent substrate glass ... must have at least all of
the following features: ... less than 1 % by weight of BaO ... ").
Many of the other arguments raised by Appellants are directed to
deficiencies in the teaching of the references individually, and fail to explain why
the Examiner erred in determining the claims would have been obvious over the
combined teachings of the references. See, e.g., Ans. 10 (addressing Appellants'
arguments regarding alleged deficiencies in Lu). Appellants rely in large part on
attorney arguments, rather than persuasive evidence. For example, Appellants
assert criticality in the specifically claimed amounts of components (see App. Br.
26-27), but have not provided persuasive evidence of such criticality (see Ans. 11-
13 (explaining the deficiencies in Appellants' evidence)). See In re Peterson, 315
F.3d 1325, 1330 (Fed. Cir. 2003) ("[T]he existence of overlapping or
encompassing ranges shifts the burden to the applicant to show that his invention
would not have been obvious."); Sud-Chemie, Inc. v. Multisorb Techs., Inc., 554
F.3d 1001, 1009 (Fed. Cir. 2009) ("[E]vidence of unexpected results and other
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Appeal 2016-006428
Application 12/775,912
secondary considerations will not necessarily overcome a strong prima facie
showing of obviousness").
In sum, for the reasons stated in the Answer and above, Appellants have not
convinced us of reversible error in the Examiner's conclusion of obviousness.
Accordingly, we sustain the rejection of 30, 33-36, 38, 39, 41, and 42 under pre-
AIA 35 U.S.C. § 103(a) as unpatentable over Buller in view of Speit, Kurachi, Lu,
and Dhere.
No time period for taking any subsequent action in connection with this
appeal may be extended under 37 C.F.R. § 1.136(a)(l )(iv).
AFFIRMED
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