EPISTAR CORPORATION

Patent Trials and Appeals Board

May 15, 2020

2019004462 (P.T.A.B. May. 15, 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.
14/847,169 09/08/2015 Yu-Chen YANG P8418US00 7417
30671 7590 05/15/2020
DITTHAVONG & STEINER, P.C.
Keth Ditthavong
44 Canal Center Plaza
Suite 305
Alexandria, VA 22314
EXAMINER
GAUTHIER, STEVEN B
ART UNIT PAPER NUMBER
2893
NOTIFICATION DATE DELIVERY MODE
05/15/2020 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):
docket@dcpatent.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte YU-CHEN YANG

____________

Appeal 2019-004462
Application 14/847,169
Technology Center 2800
____________

Before N. WHITNEY WILSON, JEFFREY R. SNAY, and
JANE E. INGLESE, Administrative Patent Judges.

INGLESE, Administrative Patent Judge.

DECISION ON APPEAL
Appellant1 requests our review under 35 U.S.C. § 134(a) of the
Examiner’s decision to finally reject claims 8–13 and 21.2 We have
jurisdiction over this appeal under 35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word “Appellant” to refer to the “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies Epistar Corporation as the real party
in interest. Appeal Brief filed October 23, 2018 (“Appeal Br.”) at 1.
2 Final Office Action entered July 25, 2018 (“Final Act.”) at 1.
Appeal 2019-004462
Application 14/847,169

2
CLAIMED SUBJECT MATTER
Appellant claims a light-emitting die. Appeal Br. 1–2. Claim 8, the
sole pending independent claim, illustrates the subject matter on appeal, and
reads as follows:
8. A light-emitting die, comprising:
a transparent substrate; and
a light-emitting stack formed on a surface of the transparent
substrate,
wherein the transparent substrate has a substrate surface
area A (mil2) and a substrate thickness Tsub (μm)
that satisfy the following relationship:
Tsub ≥ 0.1048 x A + 115.82,
wherein Tsub represents a numerical part of the substrate
thickness by taking “μm” as unit of substrate
thickness, and A represents a numerical part of the
substrate surface area by taking “mil2” as unit of
substrate surface area.

Claims Appendix filed November 30, 2018, at 3 (emphasis added).
REJECTIONS
The Examiner maintains the following rejections in the Examiner’s
Answer entered March 20, 2019 (“Ans.”):
I. Claims 8, 9, 11–13, and 21 under 35 U.S.C. § 103 as
unpatentable over Gee3 in view of Wierer,4 Slocum,5 and Yang;6 and

3 Gee et al., US 6,969,874 B1, issued November 29, 2005.
4 Wierer, Jr. et al., US 6,514,782 B1, issued February 4, 2003.
5 Amanda Slocum, A Technology Assessment of Light Emitting Diode (LED)
Solid-State Lighting for General Illumination, Working Paper #05-04, U.S.
Environmental Protection Agency (2005).
6 Hua Yang et al., The Effects of Sapphire Substrates Processes to the LED
Efficiency, 6841 Proc. Of SPIE, 68410M (2007).
Appeal 2019-004462
Application 14/847,169

3
II. Claim 10 under 35 U.S.C. § 103 as unpatentable over Gee in
view of Wierer, Slocum, and Lin.7
FACTUAL FINDINGS AND ANALYSIS
Upon consideration of the evidence relied upon in this appeal and
each of Appellant’s contentions, we affirm the Examiner’s rejections of
claims 8–13 and 21 under 35 U.S.C. § 103, for the reasons set forth in the
Final Action, the Answer, and below.
We review appealed rejections for reversible error based on the
arguments and evidence Appellant provides for each issue Appellant
identifies. 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”)).
Appellant presents arguments directed to independent claim 8 only,
and “does not separately argue the patentability of any dependent claim.”
Appeal Br. 3. We, therefore, decide the present appeal based on
independent claim 8 alone, and the remaining claims stand or fall with claim
8. 37 C.F.R. § 41.37(c)(1)(iv).
The Examiner finds that Gee discloses a light-emitting die comprising
a transparent substrate and a light-emitting stack formed on a surface of the
substrate. Final Act. 3 (citing Gee col. 3, ll. 47–55; Fig. 3). The Examiner
finds that Gee discloses that the transparent substrate has a thickness of 100

7 Lin et al., US 2014/0124734 A1, published May 8, 2014.
Appeal 2019-004462
Application 14/847,169

4
to 1000 µm, but “is silent as to the substrate surface area of the light-
emitting die.” Final Act. 3 (citing Gee col. 4, ll. 19–20). The Examiner
finds, however, and it is apparent, that “every transparent substrate for a
light-emitting die has a non-zero substrate surface area.” Final Act. 3. The
Examiner finds that Gee fails to explicitly disclose that the transparent
substrate has a substrate thickness Tsub (μm) and a substrate surface area A
(mil2) that satisfy the following relationship recited in claim 8: Tsub ≥ 0.1048
x A + 115.82. Id.
The Examiner finds, however, that Wierer discloses a light-emitting
die having a substrate surface area greater than 160,000 μm2 (about 248
mil2), and Slocum teaches that typical LEDs are about 0.25 mm2 (about 387
mil2), while modern high-brightness LEDs are up to 1 mm2 (about 1,550
mil2). Final Act. 4 (citing Slocum p. 24); see also Wierer col. 3, ll. 6–8.
The Examiner determines that “it would have been an obvious matter
of design choice” to one of ordinary skill in the art before the effective filing
date of the present application to choose a substrate surface area of 248 mil2
as disclosed in Wierer, or a substrate surface area of 387 mil2 or 1,550 mil2
as disclosed in Slocum, for Gee’s light emitting die, depending on the
amount of light to be produced and the amount of power to be consumed for
a desired application. Final Act. 4. The Examiner determines that once such
a substrate surface area is chosen, Gee “teaches a device having a substrate
thickness within the scope of Applicant’s claimed relationship.” Id.
Specifically, the Examiner determines that according to the relationship
recited in claim 8, a substrate surface area of 248 mil2 corresponds to a
substrate thickness greater than or equal to about 142 μm, a substrate surface
area of 387 mil2 corresponds to a substrate thickness greater than or equal to
Appeal 2019-004462
Application 14/847,169

5
about 156 μm, and a substrate surface area of 1,550 mil2 corresponds to a
substrate thickness greater than or equal to about 278 μm, and each of these
thickness is within the substrate thickness range of 100 to 1000 µm taught
by Gee. Id.
The Examiner further relies on Yang’s disclosure of a light-emitting
diode comprising a conductive n-type later, an active layer, and a p-type
layer (light-emitting stack) formed on the surface of a sapphire substrate
(which is transparent). Yang p. 2. The Examiner finds that Yang discloses
that increasing the thickness of the substrate up to a certain point improves
the light extraction efficiency of the light-emitting diode, after which further
increases in substrate thickness yield negligible gains in light extraction
efficiency. Final Act. 4 (citing Yang Abst.; Fig. 2); see also Yang p. 3.
In view of this disclosure in Yang, the Examiner determines that it
would have been obvious to one of ordinary skill in the art before the
effective filing date of the present application “to form the substrate
thickness into Applicant’s claimed relationship, in order to maximize light
extraction efficiency, while simultaneously limiting cost.” Final Act. 4.
Appellant argues that none of the applied prior art references,
considered individually or in combination, disclose, or would have
suggested, that the relationship between the thickness and surface area of a
substrate for a light-emitting die is a result-effective variable that impacts the
light-extraction efficiency of the light-emitting die. Appeal Br. 4–8.
Appellant argues that the applied prior art references, therefore, would not
have led one of ordinary skill in the art “to optimize the thickness of the
substrate and its surface area motivated by a reasonable expectation of
achieving any recognizable objective, let alone to optimize the light-
Appeal 2019-004462
Application 14/847,169

6
extraction efficiency of the LED device.” Id. at 8.
Appellant’s arguments, however, do not persuasively address the
rejection as presented by the Examiner, and the arguments, therefore, do not
identify reversible error in the Examiner’s rejection. Specifically, Appellant
does not dispute the Examiner’s factual findings related to the disclosures of
any of Gee, Wierer, Slocum, or Yang. Compare Final Act. 3–4, with Appeal
Br. 4–8. Nor does Appellant dispute the Examiner’s determination that it
would have been obvious to one of ordinary skill in the art before the
effective filing date of the present application to design the substrate of
Gee’s light emitting die to have a surface area as disclosed in Wierer or
Slocum, which would result in Gee’s light emitting die having a substrate
thickness that satisfies the relationship recited in claim 8, and is within the
thickness range of 100 to 1000 µm as disclosed in Gee. Compare Final Act.
4, with Appeal Br. 4–8; see also PAR Pharm., Inc. v. TWI Pharm., Inc., 773
F.3d 1186, 1195 (Fed. Cir. 2014) (concept of inherency, when applied to
obviousness, is present “when the limitation at issue is the ‘natural result’ of
the combination of prior art elements”); In re Oelrich, 666 F.2d 578, 581
(CCPA 1981) (explaining that it has long been settled that in the context of
obviousness, the “mere recitation of a newly discovered function or
property, inherently possessed by things in the prior art, does not distinguish
a claim drawn to those things from the prior art.”).
Because Appellant does not challenge the Examiner’s factual
findings, reasoning, or legal determination of obviousness, Appellant’s
arguments, including Appellant’s assertion that the applied prior art
references do not disclose, and would not have suggested, that the
relationship between the thickness and surface area of a substrate for a light-
Appeal 2019-004462
Application 14/847,169

7
emitting die is a result-effective variable that impacts the light-extraction
efficiency of the light-emitting die, do not identify reversible error in the
Examiner’s rejection.
Appellant argues that the Examiner ignores the “representations and
objective evidence of non-obviousness” provided in Appellant’s
Specification. Appeal Br. 8–9 (citing Spec. ¶¶ 19–24; Figs. 2–5). Appellant
argues that the “Examiner never provides a cogent, factually supported
reason to contradict Appellant’s position that the claimed relationship yields
unexpected results.” Appeal Br. 9–10.
Contrary to Appellant’s arguments, however, the Examiner addresses
the relied-upon disclosures in Appellant’s Specification in the Final Action,
and provides a reasoned explanation as to why the disclosures are
insufficient to demonstrate unexpected results, which Appellant does not
challenge. Compare Final Act. 9, with Appeal Br. 3–10. More specifically,
the Examiner determines that the cited disclosures of Appellant’s
Specification “do[] not actually show any unexpected results,” but merely
disclose that when substrate thickness is increased to the saturated thickness,
the light extraction efficiency of a light-emitting die reaches its maximum
for all substrate surface areas, and increasing the substrate thickness beyond
the saturated thickness does not further increase the light extraction
efficiency. Final Act. 8–9. The Examiner determines that this effect is
illustrated in Appellant’s Figure 4, which shows “no change in the light
extraction for any area.” Final Act. 9. The Examiner determines that this
showing in the Specification does not “provide an unexpected improvement
to the device as required (MPEP 2145).” Id.
Furthermore, the Examiner provides objective evidence—explicit
Appeal 2019-004462
Application 14/847,169

8
disclosures in Yang—as to why the relationship recited in claim 8 yields
results that would have been expected by one of ordinary skill in the art,
which Appellant does not challenge. Compare Final Act. 8–9 with Appeal
Br. 3–11. As discussed above, the Examiner finds that Yang discloses that
increasing the thickness of a transparent substrate in a light-emitting diode
up to a certain point improves the light extraction efficiency of the light-
emitting diode, after which further increases in substrate thickness yield
negligible gains in light extraction efficiency. Final Act. 4 (citing Yang
Abst.; Fig. 2); see also Yang p. 3. Yang also discloses that increasing the
surface roughness of a transparent substrate for a light-emitting diode
increases the external quantum efficiency of the light-emitting diode, and as
the Examiner finds, increasing the surface roughness of the substrate
increases its surface area. Yang pp. 4–5; Fig. 6; Final Act. 9. The Examiner
finds that this disclosure in Yang would have suggested a relationship
between substrate surface area and light extraction efficiency. Final Act. 9.
The Examiner finds that Yang’s disclosure that increasing the
thickness of a substrate improves light extraction efficiency would have led
one of ordinary skill in the art to determine the thickness of a substrate
having a particular area that would maximize light extraction efficiency,
leading to identification of a substrate thickness satisfying the relationship
recited in claim 8. The Examiner determines that identifying such thickness,
therefore, would be the expected result of following the suggestions
stemming from Yang’s disclosures. Final Act. 8–9. Appellant does not
dispute this determination. Appeal Br. 4–11.
We further point out that the burden of analyzing and explaining
Specification disclosures to establish unexpected results rests with
Appeal 2019-004462
Application 14/847,169

9
Appellant. In re Klosak, 455 F.2d 1077, 1080 (CCPA 1972) (“the burden of
showing unexpected results rests on he who asserts them”). To meet this
burden, Appellant must provide objective evidence demonstrating that the
claimed subject matter imparts results that would have been unexpected by
one of ordinary skill in the art before the effective filing date of the present
application relative to the closest prior art, Yang.
On this appeal record, Appellant does not meet this burden because
Appellant does not direct us to any persuasive evidence or averment
evincing that the relied-upon disclosures provided in the Specification
actually would have been unexpected by one of ordinary skill in the art
before the effective filing date of the present application in view of Yang’s
disclosure that that increasing the thickness of a transparent substrate in a
light-emitting diode point improves the light-emitting diode’s light
extraction efficiency, and increasing the surface roughness of the transparent
substrate (substrate surface area) also increases the light-emitting diode’s
external quantum efficiency. In re Geisler, 116 F.3d 1465, 1471 (Fed. Cir.
1997) (“Geisler made no such assertion [that results were unexpected] in his
application. Nor did Geisler submit any such statement through other
evidentiary submissions, such as an affidavit or declaration under Rule 132 .
. . . Instead, the only reference to unexpected results was a statement by
Geisler’s counsel . . . that Geisler’s results were ‘surprising.’”).
Therefore, considering the totality of the evidence relied-upon in this
appeal, a preponderance of the evidence weighs in favor of the Examiner’s
conclusion of obviousness. We, accordingly, sustain the Examiner’s
rejections of claims 8–13 and 21 under 35 U.S.C. § 103.

Appeal 2019-004462
Application 14/847,169

10
CONCLUSION

Claims

35 U.S.C. § Reference(s)/Basis Affirmed Reversed
8, 9, 11–13,
21
103 Gee, Wierer,
Slocum, Yang
8, 9, 11–13,
21

10 103 Gee, Wierer,
Slocum, Lin
10
Overall
Outcome
8–13, 21

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)(iv).

AFFIRMED