Western Digital Technologies, Inc.

Patent Trials and Appeals Board

Jul 13, 2021

2020004252 (P.T.A.B. Jul. 13, 2021)

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.
14/505,440 10/02/2014 Olav Hellwig SAND-03276US0 3580
64948 7590 07/13/2021
VIERRA MAGEN/WESTERN DIGITAL
2001 Junipero Serra Blvd., Suite 515
Daly City, CA 94014
EXAMINER
CHAU, LISA N
ART UNIT PAPER NUMBER
1785
NOTIFICATION DATE DELIVERY MODE
07/13/2021 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):
patents@vierramagen.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte OLAV HELLWIG, OLEKSANDR MOSENDZ, and
DIETER K. WELLER
Appeal 2020-004252
Application 14/505,440
Technology Center 1700
Before CATHERINE Q. TIMM, N. WHITNEY WILSON and
CHRISTOPHER C. KENNEDY, Administrative Patent Judges.
TIMM, 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 1–3, 5–8, 10, 11, 13–20, and 25–29.
See Final Act. 1. We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. Appellant
identifies the real party in interest as Western Digital Technologies, Inc.
Appeal Br. 2.
Appeal 2020-004252
Application 14/505,440
2
CLAIMED SUBJECT MATTER
The claims are directed to a magnetic recording medium. See, e.g.,
claims 1 and 26. The magnetic recording medium includes a magnetic
recording structure having three magnetic recording layers. Id. Extending
through the three magnetic recording layers are composite grains of
magnetic material. Id. Segregants separate and surround the grains and these
segregants influence the size and shape of the grains. Spec. ¶ 6.
Of particular issue in this appeal are the claim limitations requiring
(a) that the total thickness of the three magnetic recording layers be between
10 nm and 20 nm and (b) that the average aspect ratio of the composite
grains be at least 1.5. Claims 1 and 26. Appellant’s Specification defines the
aspect ratio as the total thickness to average grain diameter. Spec. ¶ 116.
Claim 26, reproduced below with the key limitations italicized, is illustrative
of the claimed subject matter:
26. A magnetic recording medium, comprising:
a substrate; and
a magnetic recording layer structure positioned above the
substrate, the magnetic recording layer structure comprising:
a first magnetic recording layer comprising a first
plurality of magnetic grains surrounded by a first
segregant;
a second magnetic recording layer positioned
above the first magnetic recording layer, the second
magnetic recording layer comprising a second plurality
of magnetic grains surrounded by a second segregant;
and
a third magnetic recording layer positioned above
the second magnetic recording layer, the third magnetic
Appeal 2020-004252
Application 14/505,440
3
recording layer comprising a third plurality of magnetic
grains surrounded by a third segregant,
wherein:
the first segregant comprises carbon and a first
component,
the third segregant comprises carbon and a third
component, and
the second segregant consists of carbon and,
wherein the magnetic grains of the first, second and third
magnetic recording layers form composite magnetic grains
extending through the magnetic recording layer structure,
wherein a total thickness of the first, second and third magnetic
recording layers is between 10 nm and 20 nm and wherein an
average aspect ratio of the composite magnetic grains is at
least 1.5.
Appeal Br. 19–20 (Claims Appendix)(emphasis added).
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Peng US 8,268,462 B2 Sept. 18, 2012
Mukai US 2006/0222902 A1 Oct. 5, 2006
Takekuma US 2012/0052330 A1 Mar. 1, 2012

REJECTIONS
Claims 26, 27, and 29 are rejected under 35 U.S.C. § 103 as being
unpatentable over Takekuma in view of Mukai. Final Act. 2.
Appeal 2020-004252
Application 14/505,440
4
Claims 1–3, 5–8, 10, 11, 13–20, 25, and 28 are rejected under
35 U.S.C. § 103 as being unpatentable over Takekuma in view of Mukai and
Peng. Final Act. 4.2

OPINION
Appellant does not argue any claim apart from the others, and the
issues raised are the same for all the claims under rejection. Appeal Br. 10–
15. Thus, it will suffice for us to select claim 26 as representative for
resolving the issues on appeal.
As we stated above, the total thickness and aspect ratio requirements of
the claims are at issue in this appeal. There is no dispute on this appeal record
that Takekuma teaches a magnetic recording medium with a substrate and a
multilayer magnetic recording layer structure that includes three magnetic
recording layers, each layer including magnetic grains surrounded by
segregants as required by claim 26. Compare Final Act. 2–3, and Ans. 4–6,
with Appeal Br. 11–13, and Reply Br. 3–7. Nor is there any dispute that
Takekuma does not teach a total thickness of between 10 nm and 20 nm for
the combined three recording layers, but instead discloses examples with a 6
nm total thickness. Final Act. 3; Reply Br. 5. The Examiner relies on Mukai
as providing evidence that total thicknesses in the range of 9–16 nm was
known in the art and that with Takekuma disclosing a grain diameter of 7 nm
or less (Takekuma ¶ 60), the prior art teaches or suggests aspect ratios within
the range of the claim. Final Act. 3–4.

2 Although the Examiner lists the rejection of claim 28 separately, the
evidence relied on is the same. Thus, we include claim 28 in our listing of
the rejection over the combination of Takekuma, Mukai, and Peng.
Appeal 2020-004252
Application 14/505,440
5
Appellant contends that one of ordinary skill in the art would not have
been able to predict (or have any expectation of success) that a system
having composite grains of Takekuma’s grain size and layer thickness of
Mukai could be produced and questions the Examiner’s various subsidiary
findings regarding aspect ratio overlap and layer thickness. Appeal Br. 12–
13; Reply Br. 3–7.
Appellant has not persuaded us of a reversible error.
Although we agree with Appellant that Takekuma does not teach any
grain sizes below 6 nm (Reply Br. 3–4), we agree with the Examiner that
Takekuma does not impose any limit on the total thickness of the recording
layer structure and, thus, other known thicknesses for such structures, such
as those suggested by Mukai would have been obvious to those of ordinary
skill in the art. The lack of criticality for the thickness means that the burden
was shifted to Appellant to show that their ranges of total thickness and
aspect ratio are critical for obtaining unexpected results. See In re Aller, 220
F.2d 454, 456 (CCPA 1955) (explaining that where the general conditions of
the claimed subject matter are disclosed in the prior art, and the evidence
supports a determination that discovery of the optimum or workable ranges
would result from routine experimentation, the burden shifts to the applicant
to show that the particular range values recited in the claim produce an
unexpected result).
The goals of the prior art and Appellant are substantially the same.
Takekuma and Mukai, like Appellant, seek to form a magnetic recording
media with composite grains surrounded by non-magnetic material with the
ultimate purpose of optimizing magnetic storage capability. Spec. ¶ 3;
Takekuma ¶¶ 2, 4, 11; Mukai ¶¶ 3, 5, 12. Takekuma and Mukai, like
Appeal 2020-004252
Application 14/505,440
6
Appellant, are concerned with using non-magnetic segregants to control
grain size and shape. Spec. ¶ 1; Takekuma ¶ 11; Mukai ¶ 24.
Takekuma forms magnetic recording layer 4 from an alloy mainly
composed of FePt, but also containing a segregant, i.e., a non-magnetic
material such as carbon or silicon oxide. Takekuma ¶ 39. Recording layer 4
is formed by stacking two or more magnetic layers, each successive layer
having a decreasing concentration of the non-magnetic segregant. Id.
Although, in the preferred embodiments, Takekuma sets the film
thickness of each layer at a thickness in the range of 0.5 to 2 nm (Takekuma
¶ 39) and discloses specific embodiments where the total thickness is 6 nm
(Takekuma ¶¶ 47, 53, 54), Takekuma states no range, nor expresses any
criticality, for the total thickness. Yet Takekuma specifically discusses the
criticality of depositing a 0.5 to 2 nm thick first magnetic recording layer.
Takekuma ¶ 60. This evinces that total thickness was not viewed as
Takekuma as critical. It is the first recording layer that must be kept at a
thickness of 0.5 nm to 2 nm. Takekuma ¶¶ 13–14. This is because the
amount of non-magnetic material in this first recording layer controls the
grain diameter to a diameter of 7 nm or less throughout the successively
applied recording layers even though those follow-up layers have less
segregant. Takekuma ¶ 13.
Although Takekuma teaches specific working examples with a total
thickness of 6 nm, “a reference is not limited to the disclosure of specific
working examples.” In re Mills, 470 F.2d 649, 651 (CCPA 1972) (citation
omitted). Mukai provides evidence that forming a first recording that is
thinner than the second layer was known in the art. Mukai ¶ 89. Given the
shared goals of Appellant, Takekuma, and Mukai along with Takekuma’s
focus on the thickness of the first recording layer, and the range of
Appeal 2020-004252
Application 14/505,440
7
thicknesses suggested by Mukai, a preponderance of the evidence supports
the Examiner’s conclusion that it would have been obvious to use total
thicknesses and, by extension, aspect ratios within the range of claim 26.
This is because the ranges of claim 26 are presumed to be within the
workable and optimal ranges that the ordinary artisan would arrive at
through routine experimentation. As such, the burden has shifted to
Appellant to show criticality for their ranges for achieving unexpected
results. Aller, 220 F.2d at 456. Appellant does not rely on such evidence
here.
CONCLUSION
The Examiner’s decision to reject claims 1–3, 5–8, 10, 11, 13–20, and
25–29 is AFFIRMED.
DECISION SUMMARY
In summary:
Claim(s)
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
26, 27, 29 103 Takekuma, Mukai 26, 27, 29
1–3, 5–8,
10, 11, 13–
20, 25, 28
103 Takekuma, Peng,
Mukai
1–3, 5–8,
10, 11, 13–
20, 25, 28

Overall
Outcome
1–3, 5–8,
10, 11, 13–
20, 25–29

Appeal 2020-004252
Application 14/505,440
8
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