SHARP KABUSHIKI KAISHA

Patent Trials and Appeals Board

Apr 28, 2021

2020003427 (P.T.A.B. Apr. 28, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
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
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
15/178,939 06/10/2016 Satoshi TANAKA HWB-914-434 4831
23117 7590 04/28/2021
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON, VA 22203
EXAMINER
MCCLAIN, WILLIAM E
ART UNIT PAPER NUMBER
1721
NOTIFICATION DATE DELIVERY MODE
04/28/2021 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):
PTOMAIL@nixonvan.com
pair_nixon@firsttofile.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte SATOSHI TANAKA and YOSHIHIRO OHISHI
Appeal 2020-003427
Application 15/178,939
Technology Center 1700
Before ADRIENE LEPIANE HANLON, SHELDON M. MCGEE,
JANE E. INGLESE, Administrative Patent Judges.
MCGEE, Administrative Patent Judge.
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 2–13 and 15–18. We have jurisdiction.
35 U.S.C. § 6(b).
We affirm.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies the real party in interest as Sharp
Kabushiki Kaisha. Appeal Br. 3.
Appeal 2020-003427
Application 15/178,939
2
CLAIMED SUBJECT MATTER
The claims are directed to a solar cell having a main grid electrode
and a sub grid electrode, each of which comprise silver particles. An
average thickness in a center portion of the main grid electrode is no greater
than 10.5 microns, and is thinner than an average thickness in a center
portion of the sub grid electrode. See independent claim 2. The claims also
cover methods of producing such a solar cell. See independent claim 11.2
Independent claim 2, reproduced below, is illustrative of the claimed
subject matter:

2. A solar cell comprising:
a substrate;
a sub grid electrode and a main grid electrode directly
contacting the substrate;
wherein the main grid electrode and the sub grid electrode
comprise silver particles, and
wherein a particle size of the silver particles comprised in
the main grid electrode is smaller than a particle size of the silver
particles comprised in the sub grid electrode;
wherein an average thickness in a center portion of the
main grid electrode is thinner than an average thickness in a
center portion of the sub grid electrode; and
wherein the average thickness in the center portion of the
main grid electrode is less than or equal to 10.5 μm.

2 In the event of further prosecution, Appellant is directed to an apparent
typographical error in claim 11––i.e., “wherein a particular [sic, particle]
size of the silver particles comprised in the main grid electrode is smaller
than a particle size of the silver particles comprised in the sub grid
electrode.” Appeal Br. 21 (emphasis added).
Appeal 2020-003427
Application 15/178,939
3
STATEMENT OF THE CASE
The Rejections
The Examiner rejects claims 2–13 and 15–18 under 35 U.S.C.
§ 103(a) as unpatentable over the combined disclosures of Borenstein3 and
Tanaka,4 with or without additional prior art.5 Final Act. 4–24.
Specifically, the Examiner finds that Borenstein discloses all the
limitations recited in claim 2 except for the requirement that an average
thickness in a center portion of the main grid electrode is less than or equal
to 10.5 μm, and is thinner than the average thickness in a center portion of
the sub grid electrode. Id. at 5–6. To address these differences between
Borenstein and claim 2, the Examiner turns to Tanaka, which the Examiner
finds discloses a solar cell with a sub grid that is thicker than the central
portion of the main grid electrode. Id. at 6. The Examiner also finds that
Tanaka discloses that silver paste is one of the most expensive materials
used in solar cells and that “by having a thinner . . . main grid/busbar
electrode, and a thicker sub grid/finger electrode, it is possible to reduce
resistance of the sub grid/finger electrodes . . . while reducing material usage
in the main grid.” Id.
Based on these combined teachings, the Examiner determines that it
would have been obvious to construct Borenstein’s electrodes in the manner
taught by Tanaka in order to reduce resistance in the sub grid electrodes and
to lower the overall cost of constructing Borenstein’s device. Id. The

3 US 5,178,685, issued January 12, 1993.
4 JP 2004/014566 A, published January 15, 2004 (as translated).
5 Wald, US 5,279,682, issued January 18, 1994; Naito, US 2009/0199897
A1, published August 13, 2009; Kawaguchi, US 2008/0314444 A1,
published December 25, 2008.
Appeal 2020-003427
Application 15/178,939
4
Examiner also determines that the skilled artisan would have been motivated
to further reduce the size of Borenstein’s main grid electrode from its
thickness––which is exemplified to be as low as 11 μm while still exhibiting
“good peel strength and bond yield”––to the claimed range of “less than or
equal to 10.5 μm” because doing so would “further reduce cost.” Id. at 7.
Appellant’s Arguments
Appellant advances three main contentions. Appeal Br. 12–18. First,
Appellant asserts that the rejection fails to establish that Borenstein teaches
or suggests the claimed differences in the particle sizes used in the main grid
electrode and sub grid electrode––i.e., that the particle size of the silver
particles in the main grid electrode are smaller than those used in the sub
grid electrode. Id. at 13–15. Next, Appellant asserts that Borenstein does
not teach the limitation requiring the main grid electrode to have an average
thickness that is less than 10.5 μm. Id. at 16–17. Finally, Appellant
contends that Tanaka does not provide a motivation for further reducing the
thickness of the main grid electrode relative to the sub-grid electrode,
particularly with respect to Borenstein’s teaching to have “silver-rich thick
film electrical contacts.” Id. at 17–18.
OPINION
We review the appealed rejections for reversible error based on the
arguments and evidence presented by Appellant. 37 C.F.R.
§ 41.37(c)(1)(iv); Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010)
(precedential), cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed.
Cir. 2011) (explaining that even if the Examiner had failed to make a prima
facie case, “it has long been the Board’s practice to require an applicant to
identify the alleged error in the examiner’s rejections”).
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Application 15/178,939
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Appellant argues all claims subject to the rejection of Borenstein and
Tanaka as a group. Appeal Br. 12–18. Therefore, we select claim 2 as
representative and decide the appeal of rejected claims 2–5, 9–13, and 18 on
the basis of claim 2 alone. 37 C.F.R. §41.37(c)(1)(iv). Furthermore, based
on Appellant’s lack of separate, substantive argument directed to the
subsidiary rejections of claims 6–8 and 15–17, these claims will likewise
stand or fall with claim 2.
We affirm the Examiner’s rejection of claim 2 for the reasons
expressed in the Final Office Action and the Answer. Final Act. 4–24; Ans.
3–16. We add the following only for emphasis.
Borenstein teaches, inter alia, two silver ink pastes––Ferro
Conductrox 3349 which contains “predominantly relatively large, oddly
shaped flakes” of silver, and Ferro FX 33-069, which “contain[s]
predominantly spherical particles” of silver. Borenstein, 8:63–64, 9:15–19.
Borenstein teaches that each of these types of silver particles are sintered,
and that Ferro Conductrox 3349 particles “sinter slowly because the large,
oddly shaped flakes do not fit well together,” resulting in an “incomplete
sintering.” Id. at 8:63–68. “In contrast, silver spheres in a silver/glass frit
paste sinter more rapidly . . . with the rate increasing as the particle size
decreases.” Id. at 9:4–7 (emphasis added); see also id. at 9:44 (disclosing
that “smaller particles are more rapidly sintered”). One such ink with
spherical particles is Ferro FX 33-069. Id. at 9:18–19.
Based on these teachings regarding sintering speed vis-à-vis particle
size, the skilled artisan would have recognized that the Ferro Conductrox
3349 particles––which sinter slowly and incompletely, and make up
Borenstein’s “fingers” 28 mapped to the claimed sub grid electrode––are
larger than the spherical particles of Ferro FX 33-069 used to “write two bus
Appeal 2020-003427
Application 15/178,939
6
bars as shown at 24 and 26” mapped to the claimed main grid electrode. Id.
at 10:52–53, 61–62.
Moreover, Appellant’s argument that Borenstein does not teach or
suggest the claimed particle size differences between the sub grid electrode
and the main grid electrode is contradicted by Appellant’s own
acknowledgement that the Ferro FX 33-069 silver ink particles are “smaller”
than the “larger” Conductrox 3349 particles. Appeal Br. 13, 14.6 Thus,
Appellant’s argument does not reveal reversible error in the Examiner’s
finding that Borenstein discloses “a particle size of the silver particles
comprised in the main grid electrode [FX 33-069] is smaller than a particle
size of the silver particles comprised in the sub grid electrode [Conductrox
3349].” Final Act. 5.
Appellant’s next argument is unpersuasive because it does not
squarely address the underlying rejection. Appeal Br. 16–17. Namely, the
Examiner does not rely on Borenstein to evince the claimed main grid
electrode average center portion thickness of less than or equal to 10.5 μm.
Final Act. 6. In fact, the Examiner expressly acknowledges that Borenstein
does not teach this limitation. Id. Moreover, we are unpersuaded by
Appellant’s assertions regarding Borenstein’s disclosure of “silver-rich thick
film electrical contacts” for reasons well-explained by the Examiner in the
Answer. Appeal Br. 17; Ans. 13. We also note that the Examiner does not
have the burden to demonstrate that Borenstein’s thick films are “the same

6 We do not consider Appellant’s untimely argument bridging pages 1 and 2
of the Reply Brief that in Borenstein’s Figures 9 and 10, Ferro Conductrox
3349 “appears to contain some smaller particles than FX 33-069.”
Appellant has not demonstrated good cause as to why this argument could
not have been raised in the Appeal Brief. 37 C.F.R. § 41.41(b)(2).
Appeal 2020-003427
Application 15/178,939
7
as” those discussed in the evidentiary reference to Zhang as Appellant’s
argument suggests. Reply Br. 3. The Examiner here was merely responding
to Appellant’s arguments (Appeal Br. 17, 18), noting that “thick film” is a
term of art, and that Borenstein’s reference to the film being “thick” was
mistakenly emphasized by Appellant. Ans. 13.
Finally, we reject Appellant’s argument that the skilled artisan would
not have been motivated to further reduce the average thickness in the center
portion of Borenstein’s main grid electrode. Appeal Br. 17–18. Tanaka
teaches that “silver paste is one of the most expensive materials” used in
solar cell manufacture and expresses a desire to reduce manufacturing costs.
Tanaka, 4. Borenstein’s electrodes undisputedly contain silver paste. See
Borenstein, Abstract, cols. 8–13. Borenstein need not teach a desire to
reduce solar cell manufacturing costs because this is already taught by
Tanaka. Indeed, Tanaka’s expressed desire to reduce manufacturing costs of
the solar cell is more than adequate to support––and is arguably unnecessary
to––the prima facie case. In re Thompson, 545 F.2d 1290, 1294 (CCPA
1976) (economic factors alone may provide motivation for proposed
modification). Moreover, our reviewing court has
repeatedly held that an implicit motivation to combine exists not
only when a suggestion may be gleaned from the prior art as a
whole, but when the “improvement” is technology-independent
and the combination of references results in a product or process
that is more desirable, for example because it is stronger,
cheaper, cleaner, faster, lighter, smaller, more durable, or more
efficient. Because the desire to enhance commercial
opportunities by improving a product or process is universal—
and even common-sensical— . . . there exists in these situations
a motivation to combine prior art references even absent any hint
of suggestion in the references themselves.
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Application 15/178,939
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DyStar Textilfarben GmbH & Co. Deutschland KG v. C.H. Patrick Co., 464
F.3d 1356, 1368 (Fed. Cir. 2006) (emphasis added).
For these reasons, and those provided by the Examiner, we sustain all
rejections on appeal.
CONCLUSION
The Examiner’s rejections are affirmed.
DECISION SUMMARY
Claim(s)
Rejected
35 U.S.C. § Reference(s) / Basis Affirmed Reversed
2–5, 9–13,
18
103(a) Borenstein, Tanaka 2–5, 9–13,
18

6, 7, 15, 16 103(a) Borenstein, Tanaka,
Wald, Naito
6, 7, 15, 16
8, 17 103(a) Borenstein, Tanaka,
Kawaguchi
8, 17
Overall
Outcome
2–13,
15–18

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