Ex Parte Yamamoto

Board of Patent Appeals and Interferences

Sep 21, 2010

10603729 (B.P.A.I. Sep. 21, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
_____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________

Ex parte KATSUMI YAMAMOTO
_____________

Appeal 2009-006967
Application 10/603,729
Technology Center 2600
______________

Before ROBERT E. NAPPI, JOHN C. MARTIN,
and ELENI MANTIS MERCADER, Administrative Patent Judges.

MARTIN, Administrative Patent Judge.

DECISION ON APPEAL1

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, or for filing a request for rehearing,
as recited in 37 C.F.R. § 41.52, begins to run from the “MAIL DATE”
(paper delivery mode) or the “NOTIFICATION DATE” (electronic delivery
mode) shown on the PTOL-90A cover letter attached to this decision.
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STATEMENT OF THE CASE
This is an appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1-19, which are all of the pending claims.
We have jurisdiction under 35 U.S.C. § 6(b). We affirm.

A. Appellant’s invention
Appellant’s invention is an image sensor having a micro-lens array in
which the lenses are separated by ridges. Specification [0001].2
Figures 4 and 6 are reproduced below.

2 Citations herein to Appellant’s Specification are to the Application as filed
rather than to corresponding Patent Application Publication 2004/0263665
A1.
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Figures 4 and 6 (and also Figures 5, 7, and 8, reproduced infra) are
cross-sectional views of a semiconductor substrate illustrating different steps
of a method for forming Appellant’s image sensor (id. at [0008]). As shown
in Figure 4, a photoresist layer deposited over the top planarizing layer 403
has been patterned to leave photoresist ridges 405 (id. at [0020]). Figure 6
shows that using isotropic etching to remove photoresist ridges leaves
triangular ridges 601 in planarizing layer (id. at [0024]).
Figure 5 is reproduced below.
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Figure 5 is a top view of circular triangular ridges formed over pixels
of an image sensor (id. at [0009]).
Figures 7 and 8 are reproduced below.

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Figure 7 shows the structure after a layer of micro-lens material has
been deposited and after portions 703 have been removed to leave micro-
lens portions 701 (id. at [0027]-[0028]). Figure 8 shows the structure after
micro-lens portions have been heated to a reflow temperature (id. at [0029]).

B. The claims
The independent claims before us are claims 1, 8, and 15, of which
claim 1 reads as follows:
1. An image sensor comprising:
a plurality of pixels formed in a semiconductor substrate,
each pixel including a light sensitive element;
a micro-lens over each of said light sensitive elements;
and
a raised ridge structure surrounding each of said micro-
lenses, wherein said raised ridge structure has a triangular
cross-section and at least partially supports said micro-lens,
wherein the micro-lens overlays a base portion of the raised
ridge structure.
Claims App. (Br. 12).
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C. The references
The Examiner’s rejections are based on the following references:
Nakai US 5,396,090 Mar. 7, 1995
Tan US 6,043,481 Mar. 28, 2000
Assadi US 6,166,369 Dec. 26, 2000

D. The rejections
Claims 1-3, 6, 8-10, 13, and 15-18 stand rejected under 35 U.S.C.
§ 103(a) for obviousness over Tan in view of Assadi. Final Action 5, para.
3.
Claims 4 and 11 stand rejected under 35 U.S.C. § 103(a) for
obviousness over Tan in view of Assadi and Applicant’s Admitted Prior Art.
Id. at 10.
Claims 5, 7, 12, 14, and 19 stand rejected under 35 U.S.C. § 103(a) for
obviousness over Tan in view of Assadi and Nakai. Id. at 11.

THE ISSUE
Appellant’s principal argument is that the references teach away from
combining their teachings in the manner proposed by the Examiner.3

3 See Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential)
(“If an appellant fails to present arguments on a particular issue — or, more
broadly, on a particular rejection — the Board will not, as a general matter,
unilaterally review those uncontested aspects of the rejection.”). Designated
as precedential at
(Continued on next page.)
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ANALYSIS
Appellant argues independent claims 1, 8, and 15 as a group (Br. 9,
para. D). We select claim 1 as representative of these claims. 37 C.F.R.
§ 41.37(c)(1)(vii) (2008).
Tan discloses an optoelectronic device that collects, transmits, and
detects light such that light collection is maximized and light loss minimized
(col. 2, ll. 25-27). The device employs lateral spacing guides that facilitate
maximum packing of lens elements, commonly referred to as a “maximum
fill factor” (col. 2, ll. 44-47).
Figure 4 of Tan is reproduced below.

Figure 4 illustrates a cross section of an assembly in accordance with
an embodiment of Tan’s invention (col. 3, ll. 17-18). A substrate 12
contains optoelectronic elements 14, which can be, for example, receptive
elements (col. 3, ll. 34-37). A light-transmissive layer member 16 or spacer

http://www.uspto.gov/ip/boards/bpai/decisions/prec/index.jsp.

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member of transmissive polymer or dielectric material has a contoured
surface 10 defining a ridged pattern “exhibiting raised portions 19 and
depressed portions 20 of the contoured surface” (col. 3, ll. 37-45). Although
neither of numerals 19 and 20 appears in Figure 4, numeral 21 (not
mentioned in Tan’s description) appears to designate the width of the raised
portions or ridges (19).
Figure 9B is reproduced in part below.
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Figure 9, which consist of Figures 9A and 9B, show the steps used to
make the assemblies depicted in Figures 4 and 5 (col. 5, ll. 20-21, 30-31).
The blocks in the left path in Figure 9B correspond to the Figure 4
embodiment. As shown in the last two blocks in that path, after lens
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material 18A has been deposited between the ridge elements in the light
transmissive material 16, heating causes the lens material to form convex
lens elements bounded by the ridge elements. The Examiner finds that “the
raised ridge structure (19) at least partially supports the micro-lens (as
shown in Fig. 9b).” Final Action 5-6.
For a teaching of forming Tan’s ridge elements with a triangular
rather than rectangular cross section, the Examiner relies on Assadi, which
discloses a microelectronic photosensitive device having reflective surfaces
for reflecting incident light towards the photosensitive element. Assadi,
col. 1, ll. 42-46.
Figure 3 of Assadi is reproduced below.

Figure 3 is a partial, enlarged side elevational view of an embodiment
of Assadi’s invention (col. 1, ll. 53-55). Light reflected from the reflective
surfaces of reflective elements 12, which are depicted in this figure as being
triangular or wedge-shaped, is diffracted by the microlens 24 towards the
photosensitive device 20 (col. 2, ll. 5-8, 46-49). In this way, reflective
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elements 12 and microlens 24 work together to improve the fill factor of the
photosensitive device 20 (col. 2, 49-51). Although elements 12 form an
orthogonal pattern in Figure 2, they “could also be curved so that a relatively
circular arrangement may be provided around each photosensitive device
20” (col. 2, ll. 30-34). Assadi further discloses that the microlenses can be
formed before or after the formation of reflective elements 12. See col. 3, ll.
55-57 (“In some embodiments using reflective surfaces and microlenses, it
may be desirable to form the microlenses first, for example using
conventional microlens material.”). Assadi also explains that the
microlenses take the form of conventional microlenses, which “may be
formed by depositing a suitable material at 90º C. for thirty seconds, and
postbaking and reflow at 140º C. for ninety seconds, as examples” (col. 3, ll.
58-60).
The Examiner concluded that “[i]t would have been obvious . . . to
have included the raised ridge structure having a triangular cross-section, as
taught by Assadi, with the image sensor of Tan” because “Assadi teaches . . .
[that] having a raised ridge structure with a reflective triangular cross-
section allows more light to be reflected to the micro-lens for diffraction
towards the photosensitive device, thereby improving the fill factor of the
photosensitive device.” Final Action 6. The Examiner responded to
Appellant’s “teaching away” argument by explaining that the references are
properly combinable because they are both concerned with improving the
fill factor (i.e., light collecting efficiency) of microlenses:
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Assadi teaches the reflective surfaces (12) and the microlens (24)
work together to improve the fill factor of the photosensitive
device (20) (Col. 2, lines 42 – 53) and Tan teaches the lateral
spacing guides facilitate maximum packing of lens elements, such
optimized packing is commonly referred to as “maximum fill
factor” (Col. 2, lines 42 – 47).
(Answer 12.)
Appellant argues that the references teach away from the proposed
combination because combining Tan with Assadi “makes Assadi
unsatisfactory for its intended purpose” (Br. 7). See KSR Int’l Co. v. Teleflex
Inc., 550 U.S. 398, 416 (2007) (when the prior art teaches away from a
combination, that combination is more likely to be nonobvious); In re ICON
Health & Fitness, Inc., 496 F.3d 1374, 1382 (Fed. Cir. 2007) (“a reference
teaches away from a combination when using it in that combination would
produce an inoperative result”). Specifically, after correctly noting that the
apparent purpose of the ridges 19 in Tan is to separate the microlenses 18
from each other and that the apparent purpose of the reflective surfaces 12 in
Assadi is to more efficiently diffract incoming light into the pixel 20,
Appellant agues that
[t]he fact that the surfaces 12 are reflective is the operative factor.
Any modification that diminishes the purpose of the reflective
surfaces 12 in Assadi would not be appropriate. That is, if a
person of ordinary skill were to combine the ridges in Tan with
the reflective surfaces in Assadi more light would not be reflected
to the microlens 24 of Tan. To the contrary, during the reflow
process the microlens would take up space on the reflective
surface 12. As a result, less light would be reflected to the
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microlens. This would defeat the purpose of Tan [sic: Assadi],
which is to increase the amount of light reflected to the microlens.
(Br. 7.) We are not persuaded by this argument. Although the ordinarily
skilled artisan would have recognized that covering the lower surface
portions of Assadi’s reflective elements 12 with microlens material will
reduce the amount of reflected light, we are of the opinion that the artisan, in
view of Tan, would have accepted such a reduction in reflected light in
exchange for being able to use the lower surface regions of the triangular
elements 12 to define the outer edges of the microlenses (formed using a
conventional reflow process) and thereby increase the size and light-
collecting ability of the microlenses, as taught by Tan. Alternatively, the
artisan would have recognized, in view of Assadi, that the size and thus the
light-collecting ability of the microlenses in Tan’s Figure 4 assembly can be
increased by forming the ridge elements with a triangular (rather than
rectangular) cross section and causing at least the lower surface regions of
the triangular ridge elements to be covered by the microlenses. Furthermore,
the artisan would have recognized that this modification will result in an
increase in the light-collecting efficiency whether or not the ridge elements
are reflective but that reflective ridge elements will yield a greater increase
in light-collecting efficiency because their uncovered surface portions will
reflect light to the microlenses.
For the foregoing reasons, we are of the opinion that the Examiner’s
rejection comports with the KSR principles that “when a patent claims a
structure already known in the prior art that is altered by the mere
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substitution of one element for another known in the field, the combination
must do more than yield a predictable result,” 550 U.S. at 416, and
[c]ommon sense teaches . . . that familiar items may have obvious
uses beyond their primary purposes, and in many cases a person of
ordinary skill will be able to fit the teachings of multiple patents
together like pieces of a puzzle. . . . A person of ordinary skill is
also a person of ordinary creativity, not an automaton.”
Id. at 420-21. Appellant’s arguments (Br. 8) that the results of combining
the reference teachings would not have been predictable and that the artisan
would have had no reasonable expectation of success in combining the
teachings are unpersuasive.
For the foregoing reasons, we will sustain the rejection of independent
claims 1, 8, and 15 for obviousness over Tan in view of Assadi. For the
same reasons, we will sustain the rejection on same ground of dependent
claims 2, 3, 6, 9, 10, 13, and 16-18, which are not separately argued. In re
Nielson, 816 F.2d 1567, 1572 (Fed. Cir. 1987).
We will also sustain the rejection of dependent claims 4 and 11 for
obviousness over Tan in view of Assadi and the Admitted Prior Art because
Appellant has not separately argued the merits of those claims. Id. We will
likewise sustain the rejection of dependent claims 5, 7, 12, 14, and 19, which
are not separately argued, for obviousness over Tan in view of Assadi and
Nakai. Id.
In summary, all of the Examiner’s rejections under 35 U.S.C. § 103(a)
are sustained.

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DECISION
The Examiner’s decision that claims 1-19 are unpatentable is
affirmed. 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). See 37
C.F.R. § 1.136(a)(1)(v) (2009).

AFFIRMED

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