Panasonic Intellectual Property Management Co., Ltd.

Patent Trials and Appeals Board

Sep 1, 2020

2019005638 (P.T.A.B. Sep. 1, 2020)

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.
14/695,670 04/24/2015 Hirotada INOUE YKI0489US 1037
23413 7590 09/01/2020
CANTOR COLBURN LLP
20 Church Street
22nd Floor
Hartford, CT 06103
EXAMINER
MALLEY JR., DANIEL PATRICK
ART UNIT PAPER NUMBER
1726
NOTIFICATION DATE DELIVERY MODE
09/01/2020 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):
usptopatentmail@cantorcolburn.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte HIROTADA INOUE, KAZUNORI FUJITA, and
YASUKO HIRAYAMA
Appeal 2019-005638
Application 14/695,670
Technology Center 1700
Before LINDA M. GAUDETTE, JAMES C. HOUSEL, and
BRIAN D. RANGE, Administrative Patent Judges.
HOUSEL, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1, 4–7, and 9–11 under 35 U.S.C.
§ 103(a) as unpatentable over Geerligs (US 2012/0181667 A1, pub. July 19,
2012) in view of Nakai (US 6,207,890 B1, iss. Mar. 27, 2001). We have
jurisdiction under 35 U.S.C. § 6(b).

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 Panasonic
Intellectual Property Management Co., Ltd. Appeal Brief (“Appeal Br.”)
filed July 27, 2018, 2.
Appeal 2019-005638
Application 14/695,670

2
We AFFIRM.2
CLAIMED SUBJECT MATTER
The invention relates to a solar cell having plurality of texture
elements comprising square pyramids. Spec. ¶ 5. Appellant discloses that
such texture elements reduce the reflection of light incident on the solar cell,
but are easily broken, risking power generation efficiency. Id. ¶¶ 2, 5. The
claimed invention is said to solve this problem by providing texture elements
with a curvature radius at their vertices larger than a curvature radius of the
valleys between adjacent pyramids. Id. ¶ 5.
Claim 1, reproduced below from the Claims Appendix to the Appeal
Brief, is illustrative of the claimed subject matter:
1. A solar cell comprising:
a crystalline semiconductor substrate;
an amorphous semiconductor layer formed on a first
principal face on the crystalline semiconductor substrate; and
an electrode formed on the amorphous semiconductor
layer;
wherein the first principal face of the amorphous
semiconductor layer comprises a plurality of texture elements
formed adjacent to each other,
the plurality of texture elements comprises a plurality of
first texture elements;

2 This Decision also cites to the Specification (“Spec.”) filed April 24, 2015,
the Final Office Action (“Final Act.”) dated January 30, 2018, the
Examiner’s Answer (“Ans.”) dated May 16, 2019, and the Reply Brief
(“Reply Br.”) filed July 15, 2019.
Appeal 2019-005638
Application 14/695,670

3
each of the plurality of first texture elements is an
approximate rectangular pyramid having a vertex P,
rectangular pyramids of adjacent first texture elements
share a base edge;
a valley having a lowest point V is formed between
inclined planes of adjacent first texture elements;
wherein the approximate rectangular pyramid forming
each of the plurality of first texture elements comprises a
plurality of inclined planes;
wherein a cross section of each inclined plane comprises
a first point proximate to the vertex P where a slope of the
inclined plane changes and a second point proximate to the
lowest point V between the inclined plane and an adjacent
inclined plane where a slope of the inclined plane changes;
wherein a curvature radius of a first arc including a
vertex P and the first points of inclined planes facing each other
across the vertex P is larger than a curvature radius of a second
arc including lowest point V and the second points of adjacent
inclined planes facing each other across the lowest point V;
wherein a number of vertexes of the plurality of the first
texture elements is 50% or more of a total number of vertexes
of the plurality of texture elements.
Independent claim 7 recites a solar cell having pyramidal
texture elements, at least 50% of which have a cross section of an
inclined plane with a first point proximate the vertex where a slope of
the plane changes.
OPINION
We review the appealed rejection for error based upon the issues
Appellant identifies, and in light of the arguments and evidence produced
thereon. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential)
Appeal 2019-005638
Application 14/695,670

4
(cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011)
(“[I]t has long been the Board’s practice to require an applicant to identify
the alleged error in the examiner’s rejections.”). After considering the
argued claims and each of Appellant’s arguments, we are not persuaded of
reversible error in the pending rejection. We offer the following for
emphasis only.
Appellant argues the rejected claims as a group. For purposes of this
appeal, claims 1 and 7 will be treated separately as explained below. In
accordance with 37 C.F.R. § 41.37(c)(1)(vi), claims 4–6 and 9–11 stand or
fall with claim 1.
Claim 1
The Examiner finds that Geerligs teaches a solar cell substantially as
recited in claim 1, but fails to expressly disclose that the textured
semiconductor layer is an amorphous silicon layer with electrodes formed
thereon. Ans. 4–7. However, the Examiner finds Geerligs teaches the use of
electrodes with an amorphous silicon layer. Id. at 4. In addition, the
Examiner finds that Geerligs teaches that at least 50% of the pyramidal
peaks and the valleys between adjacent pyramids are rounded such that the
curvature of the peaks is larger than the curvature of the valleys. Id. at 5–6.
The Examiner finds that Nakai also applies certain rounding to a random
pyramid texture, particularly a slight rounding of the valleys between the
pyramids, which enhances passivation. Id. at 7. The Examiner further finds
that Nakai teaches an amorphous silicon layer between a crystalline silicon
substrate and a transparent conductive layer, wherein the amorphous layer
can reduce defects at the interface with the crystalline substrate. Id. The
Examiner concludes that it would have been obvious to provide Geerligs’
Appeal 2019-005638
Application 14/695,670

5
solar cell with an amorphous silicon layer over the crystalline semiconductor
substrate in order to reduce defects at the interface with the crystalline
substrate as Nakai teaches. Id.
Appellant argues that Geerligs and Nakai fail to teach or suggest that
the number of vertices of the plurality of first texture elements is at least
50% of the total number of vertices of the plurality of texture elements.
Appeal Br. 4–5. Appellant asserts that “Figures 21c–d of Geerligs
respectfully provide no information whatsoever regarding the total number
of vertexes of the plurality of texture elements, or what percentage of these
vertexes are vertexes of the specifically claimed first texture elements.” Id.
at 4 (emphasis omitted). Appellant contends that the Examiner relies on
personal knowledge in interpreting Geerligs because this reference fails to
teach or suggest this feature. Id. Appellant also contends that the Examiner
misinterprets Geerligs, Figure 19a, in that the valleys and vertices
correspond to the portions labeled as P and V respectively, wherein the
valleys are rounded. Id. at 4–5. Appellant asserts that Geerligs actually
appears to show that the vertices in most of the texture elements are sharp.
Id. at 5.
Appellant further argues that Geerligs and Nakai also fail to teach or
suggest that the first arc curvature at the vertices is larger than the second arc
curvature at the valleys. Appeal Br. 6–8. Appellant asserts that “Figures [21c
and 21d] of Geerligs merely show perspective views and therefore it is
respectfully not possible to determine a relationship between curvatures of
the vertices and valleys.” Id. at 6 (emphasis omitted). Appellant also
contends that because Geerligs, Figure 21c, merely shows an intermediate
step, an ordinary artisan would not have combined Geerligs and Nakai as the
Appeal 2019-005638
Application 14/695,670

6
Examiner proposes. Id. at 6–7. In this regard, Appellant asserts that Figure 7
shows a BSF layer stacked on surface 30 which has the same shape as those
shown in Figures 21c and 21d. Id.
Appellant’s arguments are not persuasive of reversible error. To
begin, we note that claim 1 does not recite that the vertices and valleys are
rounded and, therefore, have a radius of curvature. Rather, claim 1 recites
that the first texture elements are approximate rectangular pyramids having a
plurality of inclined planes,
wherein a cross section of each inclined plane comprises a first
point proximate to the vertex P where a slope of the inclined
plane changes and a second point proximate to the lowest point
V between the inclined plane and an adjacent inclined plane
where a slope of the inclined plane changes.
Claim 1. In other words, the slope of the pyramid changes at two points—a
first point proximate the vertex and a second point proximate the lowest
point in the valley. This limitation does not require that the pyramid be
rounded, but instead that the slope changes to be either steeper or shallower.3
There is no dispute that Geerligs teaches a solar cell whose surface
includes a plurality of adjacent, approximately pyramidal texture elements.
Nor is there any dispute that Geerligs teaches etching these texture elements
so as to partially smooth them which, at least, imparts rounded valleys

3 Although we agree with Appellant that the Examiner misinterprets
Geerligs, Figure 19a, by labeling the valleys and vertices incorrectly
(Geerligs teaches that this figure “may equally display the textured front
surface 2a after partly smoothening” thus indicating that there is no
difference between the front and back surfaces (Geerligs ¶ 204)), we need
not rely on this erroneous interpretation in order to sustain the Examiner’s
rejection. Accordingly, we hold the Examiner’s misinterpretation of Figure
19a to be harmless error.

Appeal 2019-005638
Application 14/695,670

7
between the texture elements. Instead, Appellant contests the Examiner’s
findings that Geerligs teaches that the vertices of the texture elements are
also rounded, that any rounding of the vertices yields a larger arc of
curvature than at the valleys, and that such rounded texture elements number
50% or more of the total number of texture elements.
Appellant discloses that isotropic etching, i.e., the etchant is in a high
temperature state such as 85°C, produces “texture elements 10a and 10b
formed on the substrate 10 [that] assume the shape of a substantially square
pyramid whose vertexes and valleys are sharp.” Spec. ¶ 25. Conversely,
Appellant teaches that the etching of the texture elements is performed using
anisotropic etching, i.e., the etchant is in a low temperature state such as
40°C, such that “the etching proceeds more at the vertexes of the texture
elements 10a and 10b that have been formed on the substrate 10 than at the
valleys.” Id. Appellant further discloses that this anisotropic etching results
in “the curvature radius of the vertexes may be made larger than the
curvature radius of the valleys.” Id. Appellant does not disclose any further
details with regard to how this anisotropic etching is performed so as to
produce this relationship between the arc curvatures at the vertices and the
arc curvatures at the valleys.
Geerligs likewise discloses that pyramidal texture elements, which
may be isotropic, may be formed by etching, such as a wet-chemical alkaline
etch or a masked alkaline etch. Geerligs ¶¶ 11, 62. Geerligs also discloses
that it was known to apply a certain rounding to a random pyramid texture,
particularly a slight rounding of the valleys between the pyramids, to
enhance passivation. Id. ¶¶ 14–16. Geerligs further teaches that the textured
surface may be partly smoothened by wet-chemical or dry etching, which is
Appeal 2019-005638
Application 14/695,670

8
preferably very light to avoid increasing reflectance by an unacceptable
amount. Id. ¶¶ 27, 31, 32, 56, 59.
A skilled artisan would reasonably have expected that Geerligs’
etching process for forming the texture elements is different from Geerligs’
etching process for partly smoothening these elements, because Geerligs
teaches that the pyramidal texture elements are formed by etching and that
these elements then may be rounded, particularly in the valleys, by partly
smoothening via etching. Moreover, as the Examiner finds, Geerligs shows
the pyramidal texture elements after partly smoothening have rounded
vertices and broadened valleys (Figures 21c, 21d). Also, although Geerligs
does not teach what percentage of the texture elements are partly
smoothened, Geerligs teaches that the entire textured surface is partly
smoothened. Thus, those skilled in the art would have reasonably concluded
that a substantial portion, if not all, of the texture elements have been etched
to provide rounded vertices and valleys.
With regard to the requirement that the arc of curvature at the vertices
is larger than the arc of curvature at the valleys, both Appellant’s anisotropic
etching and Geerligs’ partial smoothening process are etching processes
designed to retain the overall surface texture, i.e., preserve the pyramidal
texture elements, but “round” the texture elements. Although Geerligs
focuses on ensuring that the valleys are “rounded,” Geerligs suggests that
other features of the surface texture are also “rounded.” Geerligs ¶ 14
(“applying a certain rounding to a random pyramid texture, particularly a
slight rounding (increasing the radius of curvature) of the valleys between
pyramids”). Thus, those skilled in the art would have reasonably expected
that both processes would have produced the same “rounding” of the
Appeal 2019-005638
Application 14/695,670

9
pyramidal texture elements, including the same or similar amount of
“rounding” of both the vertices and valleys. Further, although Appellant
urges that the Examiner has misinterpreted Geerligs, Figures 21c and 21d, as
showing “rounded” vertices, we disagree. In particular, Appellant fails to
show any difference between Geerligs’ scanning electron micrographs
(“SEMs”) of Figures 21c and 21d and Appellant’s SEMs of Figures 4 and 5,
nor do we perceive any.
Therefore, a preponderance of the record evidence supports the
Examiner’s position that Geerligs’ partly smoothening process performed on
the pyramidal texture elements produces at least 50% of the texture elements
having the same “rounded” vertices with arc curvatures that are larger than
the arc curvatures of the “rounded” valleys as recited in claim 1.
Furthermore, we note that Nakai teaches a similar solar cell having an
amorphous silicon layer 2 formed over a plurality of pyramidal texture
elements on the surface of a crystalline semiconductor substrate 1. Nakai,
Figs. 1, 4. As shown in Nakai, the amorphous silicon layer formed over the
substrate’s pyramidal texture elements produces pyramidal texture elements
that have both rounded vertices and valleys, wherein the arc of curvature of
at the vertices is larger than the arc of curvature at the valleys. Id. Therefore,
modifying Geerligs’ panel to include an amorphous silicon layer in view of
Nakai as the Examiner proposes would result in a solar panel having
approximately rectangular pyramids with vertices whose curvature radius is
greater than that of the valleys between the pyramids as recited in claim 1.
Accordingly, we sustain the Examiner’s obviousness rejection of
claim 1, and dependent claims 4–6 and 9–11 over the combination of
Geerligs and Nakai.
Appeal 2019-005638
Application 14/695,670

10
Claim 7
Appellant’s arguments are also not persuasive of reversible error with
regard to the Examiner’s obviousness rejection of claim 7. Initially, we note
that claim 7 does not recite the limitation that the first texture elements each
have a first arc curvature at the vertex that is larger than a second arc
curvature at the valleys of adjacent texture elements. As such, Appellant’s
second argument is inapplicable to the Examiner’s rejection of claim 7. See
In re Van Geuns, 988 F.2d 1181, 1184 (Fed. Cir. 1993) (rejecting appellants’
nonobviousness argument as based on limitation not recited in claim); In re
Self, 671 F.2d 1344, 1348 (CCPA 1982) (“Many of appellant’s arguments
fail from the outset because, as the solicitor has pointed out, they are not
based on limitations appearing in the claims.”).
Appellant’s remaining argument relevant to claim 7 is that Geerligs
fails to teach or suggest that the number of vertices of the plurality of first
texture elements, i.e., those having pyramidal shapes with changes in slope
near their vertices, is 50% or more of the total number of vertices of the
plurality of texture elements.4 For the same reasons given above with regard

4 Like claim 1, claim 7 does not require that the vertices of the first texture
elements be rounded so as to have a radius of curvature. Also, claim 7 does
not include any recitation with respect to the valleys between adjacent
texture elements. Instead, claim 7 requires that each first texture element is
an approximate rectangular pyramid having a plurality of inclined planes,
“[wherein] a cross section of each inclined plane comprises a first point
proximate to a vertex P of the rectangular pyramid where a slope of the
inclined plane changes.” Claim 7. This limitation merely requires that the
slope of each of the pyramid’s inclined planes or faces changes at a point
proximate the vertex, which encompasses both the possibility that the
inclined plane has a steeper slope at the vertex (i.e., pointier tip), and the
Appeal 2019-005638
Application 14/695,670

11
to this argument against the rejection applied to claim 1, a preponderance of
the evidence supports the Examiner’s position that at least 50% of Geerligs’
pyramidal texture elements as modified in view of Nakai would have
vertices that have changes in slope, either directly due to Geerligs’ partly
smoothening process or upon formation of the amorphous silicon layer as
shown in Nakai.
Accordingly, we sustain the Examiner’s obviousness rejection of
claim 7 over the combination of Geerligs and Nakai.
CONCLUSION
Upon consideration of the record and for the reasons set forth above
and in the Examiner’s Answer, the Examiner’s decision to reject claims 1,
4–7, and 9–11 under 35 U.S.C. § 103(a) as unpatentable over Geerligs in
view of Nakai is affirmed.
DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1, 4–7, 9–11 103(a) Geerligs, Nakai 1, 4–7, 9–11
TIME PERIOD FOR RESPONSE
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

possibility that the inclined plane has a shallower slope at the vertex (i.e., a
blunted tip).