Ex Parte Mulligan et al

Patent Trial and Appeal Board

Sep 29, 2016

12119063 (P.T.A.B. Sep. 29, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
12/119,063 05/12/2008 William P. Mulligan
74254 7590 09/30/2016
Okamoto & Benedicto LLP
P.O. Box 641330
San Jose, CA 95164-1330
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.
10031.003010 2313
EXAMINER
GARDNER, SHANNON M
ART UNIT PAPER NUMBER
1757
MAILDATE DELIVERY MODE
09/30/2016 PAPER
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.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte WILLIAM P. MULLIGAN,
MICHAEL J. CUDZINOVIC, THOMAS PASS,
DAVID SMITH, and RICHARD M. SW ANSON
Appeal2015-003621
Application 12/119,063
Technology Center 1700
Before GEORGE C. BEST, N. WHITNEY WILSON, and
JENNIFER R. GUPTA, Administrative Patent Judges.
BEST, Administrative Patent Judge.
DECISION ON APPEAL
The Examiner finally rejected claims 1, 2, 4, 6, 7, 15, 16, and 18-24
of Application 12/119,063 under 35 U.S.C. § 103(a) as obvious. Final Act.
(January 27, 2014). Appellants 1 appeal these rejections pursuant to
35 U.S.C. § 134(a). We have jurisdiction under 35 U.S.C. § 6.
For the reasons set forth below, we AFFIRM.
1 SunPower Corporation is identified as the real party in interest. Appeal
Br. 1
Appeal2015-003621
Application 12/119,063
BACKGROUND
The '063 Application describes metal contact structures for use in
photovoltaic cells. Spec. 1. In particular, the interdigitated metal contacts
are formed on the backside of a silicon photovoltaic cell comprising P-doped
and N-doped regions formed in a spaced parallel arrangement. Id. at 2.
Claim 1 is representative of the '063 Application's claims and is
reproduced below:
1. A solar cell comprising:
a plurality of P+ and N+ doped regions, wherein the P+
and N+ doped regions are abutting;
a silicon dioxide layer formed over the plurality of P+
and N+ doped regions;
a plurality of openings in the silicon dioxide layer, the
plurality of openings exposing the plurality of P+ and N+ doped
regions, the plurality of openings having a size that provides a
total contact area to the plurality of P+ and N+ doped regions
as a fraction of an entire backside of the solar cell of less than
5%; and
a plurality of metal contacts on a backside of the solar
cell, each of the plurality of metal contacts comprising
aluminum forming an infrared reflecting layer with the silicon
dioxide layer, a barrier layer over the aluminum, a plating seed
layer over the barrier layer, and a metal layer of a same material
as the plating seed layer and electroplated on the plating seed
layer to form an interdigitated gridline on the backside of the
solar cell, each of the plurality of metal contacts making an
electrical connection to a corresponding region in the plurality
of P+ and N+ doped regions through a corresponding opening
in the plurality of openings.
Appeal Br. 8 (Claims App.) (emphasis added).
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Application 12/119,063
REJECTIONS
On appeal, the Examiner maintains the following rejections:
1. Claims 1, 2, 6, 7, 15, 16, 19, and 20 are rejected under 35 U.S.C.
§ 103 (a) as unpatentable over the combination of Sinton, 2
Owyang, 3 and Borden. 4 Final Act. 3.
2. Claims 4 and 18 are rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Sinton, Owyang, Borden,
and Jao.5 Final Act. 7.
3. Claim 21 is rejected under 35 U.S.C. § 103(a) as unpatentable over
the combination of Sinton, Owyang, Borden, and Mitchell. 6 Final
Act. 8.
4. Claims 22-24 are rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Sinton, Owyang, Mitchell,
and Borden. Final Act. 9.
DISCUSSION
Appellants rely on the same arguments for the reversal of the rejection
of each of the '063 Application's independent claims. See Appeal Br. 3-7.
Accordingly, we limit our discussion to independent claim 1 with the
2 US 5,053,083, issued October 1, 1991.
3 US 4,505,029, issued March 19, 1985.
4 US 4,379,944, issued April 12, 1983.
5 US 6,415,974 B2, issued July 9, 2002.
6 US 5,773,359, issued June 30, 1998.
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Application 12/119,063
understanding that our analysis applies with equal force to independent
claims 15 and 22.
Appellants argue that the rejection of claim 1 should be reversed
because the combination of Sinton, Owyang, and Borden does not describe
or suggest a solar cell in which the plurality of openings used to connect the
metal contacts to the plurality of P+ and N+ doped regions is less than 5% of
the area of the entire backside of the solar cell. 7 Appeal Br. 3. In particular,
Appellants argue that the Examiner erred for any of three reasons: (1) the
combination of asserted references does not contain any teaching regarding
the total contact area on the backside of the solar cell, id. at 3--4; (2) Borden
does not teach or suggest a metal contact coverage range that overlaps with
the recited range of less than 5%, id. at 4--5; and (3) Borden teaches away
from the claimed range of less than 5% total contact area as a fraction of the
backside area of the solar cell, id. at 5---6.
For the reasons set forth below, we are not persuaded by any of these
arguments. Thus, we affirm the rejection of each of the appealed claims.
First, Appellants argue that the asserted combination of references
does not contain any teaching regarding the backside total contact area.
Appeal Br. 3--4. As explained below, Appellants' argument is based upon a
7 In relevant part, claim 1 recites: "A solar cell comprising: ... a plurality of
openings ... , the plurality of openings having a size that provides a total
contact area to the plurality of P+ and N+ doped regions as a fraction of the
entire backside of the solar cell of less than 5% .... " Claims 15 and 22
each recite: "A solar cell comprising: ... a plurality of metal contacts ...
wherein the plurality of metal contacts connects to the plurality of doped
regions with a total contact area of less than 5% as a fraction of an entire
backside of the solar cell."
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Application 12/119,063
misinterpretation of the Examiner's reasoning and findings of fact. Thus,
this argument is not persuasive of Examiner error.
In rejecting claim 1, the Examiner found that Sinton describes a
backside contact solar cell having a silicon dioxide layer formed over a
plurality of P+ and N+ doped regions. Final Act. 3. The Examiner further
found that Sinton also discloses a plurality of openings in the silicon dioxide
layer and a plurality of metal contacts that make electrical connections
through each of these openings. Id. (citing Sinton Figure 5h - 5j and
corresponding text). The Examiner relies upon Borden for its description of
the size of the openings in the silicon dioxide layer relative to the total area
of the backside of the solar cell. Id. at 6. Thus, contrary to Appellants;
argument the asserted combination of references does contain teachings
regarding the backside total contact area.
Second, Appellants argue:
The final office action suggests that Borden's 50% metal
contact coverage overlaps with the recited less than 5%.
Appellants respectfully disagree with this conclusion because
Borden does not disclose the lower limit of the up to 50% metal
contact coverage. As can be appreciated, the front side metal
contact coverage range cannot start at zero percent because
there must be some metal that contacts the front side doped
region. That is, "up to 50%" cannot mean from zero percent to
50% as suggested in the final office action.
Appeal Br. 5; see also Reply Br. 3.
We are not persuaded by this argument. As the Examiner explains:
The Borden reference clearly teaches a range of coverage up to
50% (column 3, lines 40 - 50) with an explicit result effective
variable result (a trade-off between lowering series resistance
and raising surface recombination). The Examiner agrees that
the front side metal contact coverage range cannot be zero
percent (as Appellant has stated) in a functioning cell.
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Application 12/119,063
However, the rejection does not assert a range of 0-50% but a
range of "up to 50%" which includes above zero to 50%.
Further, the Examiner notes that Appellant's claim to "less than
5%" also does not include 0% as 0% contact area would equate
to no metal contact to the solar cell semiconductor. Borden's
teaching of up to 50% overlaps the instantly claimed range of
less than 5%.
Answer 16-17. Appellants have not persuasively refuted this reasoning.
Third, Appellants argue that Borden teaches away from the claimed
range of less than about 5%. Appeal Br. 5---6. In particular, Appellants
argue:
Id.
While Borden discloses the tradeoff between series resistance
and surface recombination (Borden, lines 45-49), it is clear to
one of ordinary skill in the art reading Borden that the metal
contact area takes priority in the tradeoff, suggesting metal
contact coverage as high as 50%, which implies even higher
metal contact coverage if there is enough surface area for metal
deposition. Indeed, Borden discloses 100% metal contact
coverage on the backside surface because that much area is
available for metal deposition (Borden, FIG. 1, metal layer 13
on N+ region I 5).
We are not persuaded by this argument. Borden's use of 100% metal
contact coverage on the backside surface of its solar cell does not suggest
that Borden favors metal contact area in the trade-off between series
resistance and surface recombination. Rather, Borden teaches that it is able
to use 100% metal contact coverage on the backside of its solar cell only
because the solar cell is manufactured in a manner that creates a surface field
adjacent to the backside surface. This surface field reduces surface
recombination. See Borden col. 4, 11. 56-59; see also Figs. 1 and 2; col. 4, 11.
40-42.
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Application 12/119,063
CONCLUSION
For the reasons set forth above, we affirm the rejections of claims 1, 2,
4, 6, 7, 15, 16, and 18-24 of the '063 Application.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED
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