Ex Parte Donofrio et al

Patent Trial and Appeal Board

Nov 9, 2016

13018013 (P.T.A.B. Nov. 9, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/018,013 0113112011
65106 7590
MYERS BIGEL, PA
P.O. BOX 37428
RALEIGH, NC 27627
11/14/2016
FIRST NAMED INVENTOR
Matthew Donofrio
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.
5308-1381 7782
EXAMINER
NADAV,ORI
ART UNIT PAPER NUMBER
2811
NOTIFICATION DATE DELIVERY MODE
11/14/2016 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):
uspto@myersbigel.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE
THE PATENT TRIAL AND APPEAL BOARD
Ex parte MATTHEW DONOFRIO, 1
John Adam Edmond, James Ibbetson, David Todd Emerson,
Michael John Bergmann, Kevin Haberern, Raymond Rosado,
and Jeffrey Carl Britt
Appeal2015-003587
Application 13/018,013
Technology Center 2800
Before MARK NAGUMO, CHRISTOPHER L. OGDEN, and
JEFFREY R. SNAY, Administrative Patent Judges.
NAGUMO, Administrative Patent Judge.
DECISION ON APPEAL
Matthew Donofrio, John Adam Edmond, James Ibbetson,
David Todd Emerson, Michael John Bergmann, Kevin Haberern,
Raymond Rosado, and Jeffrey Carl Britt ("Cree") timely appeal
1 The real party in interest is identified as Cree, Inc. ("Cree"). (Appeal
Brief, filed 31 October 2014 ("Br."), 2.)
Appeal2015-003587
Application 13/018,013
under 35 U.S.C. § 134(a) from the Final Rejection2 of claims 1, 3-10, 16,
18-28, 62, and 64. 3 We have jurisdiction. 35 U.S.C. § 6. We reverse.
OPINION
A. Introduction4
The subject matter on appeal relates to "horizontal" white light
emitting diodes ("LEDs") having oblique substrate sidewalls coated with a
conformal phosphor layer comprising a phosphor having a specified average
equivalent particle diameter, d50. The '013 Specification reveals that such
LEDs provide relatively high brightness with relatively low angular
variation. Moreover, a relatively high ratio of yellow phosphor to (more
expensive) red phosphor may be used, resulting in a cost savings.
(Spec. 12 [0051].)
As Slater5 explains, white light may be produced from an ultraviolet
light em1ttmg LED by combining red, green, and blue light emitted by
phosphors placed on or near the ultraviolet light emitting LED. (Slater,
col. 3, 11. 28--44.) In particular, as shown in Slater Figure lB (next page),
2 Office action mailed 30 May 2014 ("Final Rejection"; cited as "FR").
3 Remaining copending claims 11-15, 29-33, 35-39, 63, and 65 have been
withdrawn from consideration (FR 1, § 5a), and are not before us.
4 Application 13/018,013, Horizontal light emitting diodes including
phosphor particles, filed 31 January 2011. We refer to the
'"013 Specification," which we cite as "Spec."
5 Seen. 13, infra, for the complete citation. Slater is incorporated into
the '013 Specification by reference. (Spec. 9 [0038].)
2
Appeal2015-003587
Application 13/018,013
conventional white LED devices have a diode region 1106 on first face lOOa
of a substrate 100. Blue or ultraviolet light emitted from diode region 1107
is conducted out of the device through transparent substrate 100 and then
through phosphor layer 120 on second face lOOb as well as vertical side
faces lOOc and oblique side faces lOOd.
{Slater Figures lB (left) and 2B (right) are shown below}
120}
{Fig. lB shows a prior art LED with
diode layer 110 and vertical side
walls 1 OOc coated with
nonconformal phosphor layer 120}
220_\ /~uuuuu t'::::::==~~~:::.:.:.~:.:~\
1'X./ 200b \\
~
\
·. . . \
200d
200
200d.J 1
OOe 2ooa1 200e-,: ~---------- """"4
••••••w""""""""w<-y«««« ....... ~
\..210
{Fig. 2B shows an LED with diode
layer 210 and oblique
sidewalls 200d coated with
conformal phosphor layer 220}
According to Slater, it may be difficult to obtain sufficient coverage of
phosphor coating 120 on vertical walls 1 OOc without excessive coating on
6 Throughout this Opinion, for clarity, labels to elements are presented in
bold font, regardless of their presentation in the original document.
7 The nature of the diode region, i.e., whether "horizontal" (the anode and
cathode ohmic contacts to the p-type layer and then-type layer, respectively,
extend along the first face of the diode region) (Spec. 1 [0004], 11 [0044]) or
"vertical" (the anode and cathode ohmic contacts are on opposite faces of
the diode region) (id. at 11 [0044]) does not appear to be critical to the
operation of white light LEDs of the invention.
3
Appeal2015-003587
Application 13/018,013
oblique portions lOOd; and still poor coverage on second face lOOb may be
obtained. (Slater, col. 5, 11. 51-62.) As a result, too much blue emission
from diode region 110 may be emitted through second face 100, while too
little yellow secondary emission may be transmitted through the excessively
thick coating on face lOOd. (Id. at col. 5, 1. 62, through col. 6, 1. 6.) The
practical effect is said to be reduced conversion efficiency and a large
angular dependence of Color Correlated Temperature ("CCT").
(Id. at col. 6, 11. 6-9.) In contrast, the oblique sidewalls shown in Slater
Figure 2B are said to permit a conformal coating, which is said to "produce a
desired spectrum of light, while also allowing more radiant flux to be
emitted from the phosphor-coated LED." (Id. at 11. 14--16.)
According to the '013 Specification, "[i]t is well known that larger
phosphor particles are generally more efficient in light conversion than small
sized phosphor particles." (Spec. 9 [0039].) However, the Specification
explains; large phosphor particles may also have a lower light scattering
efficiency than smaller phosphor particles which "may produce a high
angular variation in Correlated Color Temperature (CCT), which is typical
in white LEDs using large particulate size phosphor particles for brightness
boost." (Id.) The variability of maximum change in CCT is referred to as
"max delta CCT," or "max dCCt." (Id. at 20 [0076].)
Cree reports that, contrary to expectations, a conformal phosphor
layer having phosphor particles limited to an average equivalent particle
4
Appeal2015-003587
Application 13/018,013
diameter d50 8 of between about 10 µm and about 20 µm "provide[ s]
relatively high brightness with relatively low angular variation."
(Spec. 10 [0040].)
Figure 1, reproduced below, illustrates an embodiment of the claimed
light emitting diode 100.
"'-- 1' 2n va 114
120
112 n ,.>120c '
""'t'-
-11o'b\
HOa 100
180
"182.a I )
!~:::::::-::::::::-::;:::-:::]-! --~18-)2~~--lB_;2b~1-36-=~:-::::~~~~I~
170
1J2 FIG. l 1J4
{Fig. 1 shows packaged white LED 200 in cross section}
Active diode region 110 comprises first face llOa and second
face llOb, between which are located n-type region 112 and p-type
region 114, which are connected by conductive vias 172 and 162,
respectively, to cathode ohmic contact 170 and anode contact 160,
8 The symbol "d50," denoting the "average equivalent particle diameter,"
indicates that 50 mass% of the particles have a smaller diameter. (Spec. 10,
[0041].)
5
Appeal2015-003587
Application 13/018,013
respectively, which lie in the plane of first face llOa. Light emitted from
diode region 110 travels through substrate 120 and excites, e.g., blue,
yellow, and red phosphor particles 142 in conformal phosphor layer 140 on
oblique faces 120a and on outer face 120b of substrate 120. The mixed
colors of the emitted light combine to form white light, which is gathered
and transmitted to the external world by lens 190.
Sole independent Claim 1 reads:
A light emitting diode [100] comprising:
a diode region [110] having first [llOa] and
second [llOb] opposing faces and including therein an
n-type layer [112] and a p-type layer [114];
an anode contact [160] that ohmically contacts the p-type
layer [114] and extends on the first face [llOa];
a cathode contact [170] that ohmically contacts the n-type
layer [112] and that also extends on the first face [llOa];
a transparent substrate [120] on the second face [llOb ],
the transparent substrate including
an inner face [120c] adjacent the second face [llOb],
an outer face [120b] remote from the second
face [llOb] and
a sidewall [120a] that extends from the outer
face [120b] to the inner face [120c]; and
a conformal layer [140]
that comprises phosphor [142] having an average
equivalent particle diameter d50 of between
about JOµm and about 20µm,
on the outer face [120b] and extending on the
sidewall [120a] oblique to the inner face [120c].
(Claims App., Br. 15; some indentation, paragraphing, bracketed labels to
Fig. 1, and emphasis added.)
6
Appeal2015-003587
Application 13/018,013
The Examiner maintains the following ground of rejection9:
Claims 1, 3-10, 16, 18-28, 62, and 64 stand rejected under
35 U.S.C. § 103(a) in view of the combined teachings of
Donofrio, 10 Ishii, 11 Sakane, 12 and Slater. 13
B. Discussion
Findings of fact throughout this Opinion are supported by a
preponderance of the evidence of record.
As will be seen, we need focus only on the limitations recited in
claim 1.
Cree contends first that the Examiner erred harmfully in concluding
that it would have been prima facie obvious to combine the teachings of
Donofrio regarding LED structures that "may incorporate wavelength
conversion material such as a phosphor" (Donofrio 1 [0004], last sentence)
9 Examiner's Answer mailed 28 November 2014 ("Ans.").
10 Matthew Donofrio et al., Semiconductor light emitting diodes having
reflective structures and methods of fabricating same, U.S. Patent
Application Publication 2009/0283787 Al (2009), now U.S. Patent
No. 8,368,100 (5 February 2013), assigned to Cree, Inc., the real party in
interest in this Appeal.
11 Tsutomu Ishii et al., White LED lamp, backlight, light emitting device,
display device and illumination device, U.S. Patent Application Publication
2011/0006334 Al (2011), based on an application filed 19 February 2009,
now U.S. Patent No. 8,471,283 (25 June 2013).
12 Kenji Sakane et al., Phosphor and manufacturing method for the same,
and light source, U.S. Patent No. 7,476,337 B2 (2009).
13 David B. Slater, Jr., and Gerald H. Negley, Phosphor-coated light emitting
diodes including tapered sidewalls, andfabrication methods therefore, U.S.
Patent No. 6,853,010 B2 (2005) (assigned to Cree, Inc., the real-party-in-
interest).
7
Appeal2015-003587
Application 13/018,013
with the teachings of Slater regarding a conformal layer of phosphor on the
outer face and oblique sidewalls of a substrate, wherein phosphor particles
have an average equivalent particle diameter d50 of between about 10 µm
and about 20 µmas disclosed by Ishii or Sakane. (Br. 3---6.)
Although the Examiner does overstate the teachings of Donofrio to
the extent that Donofrio is found to teach that "a conformal phosphor layer
can be incorporated into the LED structure" (FR 3, 11. 7-8), this error is
harmless in context. Donofrio teaches an LED assembly with transparent
substrate 120 having outer face 120b and oblique side walls 120a that
extend from outer face 120b to the inner face 120c, as shown in Donofrio
Figure 12, reproduced below.
{Donofrio Fig. 12 shows a cross section of an LED mounted on a substrate}
The similarity between the shape of Donofrio' s substrate 120 and the
substrate 200 illustrated by Slater in Fig. 2B, supra, together with the similar
disclosed optical function, would have suggested the application of a
conformal coating even in the absence of Donofrio' s express invitation to
incorporate a wavelength conversion material into the LED.
8
Appeal2015-003587
Application 13/018,013
As for the selection of phosphor particles having a d50 between
about 10 µm and about 20 µm, the teachings of Ishii that the average grain
size of phosphor powders should be greater than 10 µm to avoid lowered
light extracting efficiency (Ishii 5 [O 104]-[O106]) provides a sufficient
reasonable expectation of successfully using particles in the range required
by the claims. Similarly, the teachings of Sakane that d50 for phosphor
particles should be 20 µm or less (Sakane, col. 9, 1. 65, through col. 10, 1. 10,
cited by the Examiner in the Examiner's Answer (Ans., para. bridging 10-
11) would have provided further reason to select particles within the
required range. 14 The silence of Ishii and Sakane regarding oblique
sidewalls (Br. 5) is of no moment, given that both Donofrio-and, more
critically, Slater-teach oblique sidewalls, the latter emphasizing the
improved spectral and radiant flux obtained by being able to coat oblique
sidewalls with a conformal phosphor-containing layer.
Cree argues further that the Examiner erred in not giving sufficient
weight to the evidence of unexpected results. (Br. 7-11.)
First, as shown in Figure 8, reproduced on the following page, when
applied to substrates having vertical walls, the larger d50 = 15 µm phosphor
particles provide a mean max dCCT of about 7 500, compared to smaller
d50 = 5.5 µm phosphor particles, which provide a mean max dCCT of
about 3000. (Spec. 20 [0077].) This is consistent with the effect of larger
scattering particles discussed in the '013 Specification and summarized
supra.
14 It has not escaped our notice that Sakane recommends a most preferred
range of "3.0 µm or more and 15 µm or less" (Sakane, col. 10, 11. 17-18.)
9
Appeal2015-003587
Application 13/018,013
{Figure 8 is shown below}
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