MITSUBISHI ELECTRIC CORPORATION

Patent Trials and Appeals Board

Jul 30, 2021

2020006239 (P.T.A.B. Jul. 30, 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.
14/766,414 08/06/2015 Kazuo YOSHIDA 004700-ME0094 3987
78198 7590 07/30/2021
Studebaker & Brackett PC
8255 Greensboro Drive
Suite 300
Tysons, VA 22102
EXAMINER
NGUYEN, DILINH P
ART UNIT PAPER NUMBER
2894
NOTIFICATION DATE DELIVERY MODE
07/30/2021 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):
info@sbpatentlaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte KAZUO YOSHIDA and MASATO NEGISHI
Appeal 2020-006239
Application 14/766,414
Technology Center 2800
Before CHRISTA P. ZADO, DAVID J. CUTITTA II, and
PHILLIP A. BENNETT, Administrative Patent Judges.
ZADO, 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, 2, and 6–8. We have jurisdiction
under 35 U.S.C. § 6(b).
We REVERSE.

1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R.
§ 1.42(a). Appellant identifies the real party in interest as Mitsubishi
Electric Corp. Appeal Br. 2.
Appeal 2020-006239
Application 14/766,414
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CLAIMED SUBJECT MATTER
The Specification relates to a semiconductor device having a diced
device fixed on a mount substrate with an adhesive and a method of
manufacturing the semiconductor device. Spec. ¶ 1. Claim 1, reproduced
below, is illustrative of the claimed subject matter:
1. A semiconductor device comprising:
a mount substrate;
an adhesive applied to the mount substrate; and
a device having its lower surface bonded to the mount substrate
with the adhesive,
wherein a surface roughness of a side surface upper portion of a
side surface of the device is lower than that of a side surface
lower portion of the side surface of the device,
wherein, on the side surface of the device, the adhesive contacts
only the side surface lower portion,
wherein the side surface lower portion is porous, and
wherein a total width of the device at the side surface lower
portion where the adhesive is in contact is greater than a total
width of the device at the side surface upper portion.
Appeal Br. 17 (Claims App’x).
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Application 14/766,414
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REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Kang US 2009/0321953 A1 Dec. 31, 2009
Chen US 2012/0261693 A1 Oct. 18, 2012
Moulzolf US 2013/0000098 A1 Jan. 3, 2013
Engelhardt US 2013/0115755 A1 May 9, 2013
REJECTIONS
Claims 1, 2, and 6 are rejected under 35 U.S.C. § 103 as unpatentable
over the combination of Moulzolf, Chen, and Engelhardt. Final Act. 2–6.
Claims 7 and 8 are rejected under 35 U.S.C. § 103 as unpatentable
over the combination of Moulzolf, Chen, Engelhardt, and Kang. Final
Act. 6–7.
OPINION
Background
The Specification explains that the operation to cut a semiconductor
wafer longitudinally and laterally to separate the wafer into individual
devices (or chips) is called dicing. Spec. 2. Two well-known dicing
techniques include blade dicing and laser dicing. Id. Blade dicing uses an
extremely thin circular blade called a diamond blade rotated at a high speed
to cut a wafer. Id. Laser dicing cuts the wafer using laser light, wherein
concentrated laser energy sublimates, melts, or ionizes a portion of the wafer
material in order to separate the wafer. Id. ¶ 3. According to the
Specification, laser dicing has the advantage of having a higher throughput
and yield than blade dicing, but has the disadvantage that molten material
forms on the device side surfaces. Id. ¶ 7. Specifically, subsequent to
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Application 14/766,414
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dicing, the device is bonded to the surface of a substrate mount using
adhesive, wherein the adhesive—while curing—climbs up the molten
material on the side surfaces of the device. Id. When the adhesive climbs
the upper side surface of the device, it contaminates electrode pads on the
device’s top surface. Id. Therefore, it would be desirable to have an
improved technique in which adhesive does not climb the upper side
surfaces of the device, according to the Specification. Id. ¶ 9. Figure 1 of
the Specification, reproduced below, is illustrative.

Figure 1 of the Specification depicts a sectional view of
semiconductor device 10 comprising device 16 mounted on mount
substrate 12. Spec. ¶¶ 13, 15; Fig. 1. The top surface of device 16 includes
electrodes 18. Id. ¶ 15; Fig. 1. The lower portion of device 16’s side
surface—i.e., 16B—comprises molten material 20. Id. ¶ 16; Fig. 1. The
upper portion of device 16’s side surface—i.e., 16A—does not include
molten material. Id. Fig. 1. Device 16 is bonded to substrate 12 using
adhesive 14. Id. ¶¶ 21–22; Fig. 1. As shown in Figure 1, part 14A of
adhesive 14 climbs up lower side surface 16B, but does not reach upper side
surface 16A. Id. ¶ 17; Fig. 1. According to the Specification, upper side
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surface 16A has roughness Rz equal to or less than 1.0 µm and lower side
surface 16B has roughness Rz equal to or greater than 4.0 µm. Id. ¶¶ 15–16.
The Specification states that because roughness Rz of upper side surface is
reduced, it is possible to prevent adhesive 14 from reaching this surface. Id.
¶ 27.
The Specification describes a technique for producing device 16 as
shown in Figure 1 in which molten material 20 covers lower side
surface 16B but does not cover upper side surface 16A. Spec. ¶¶ 14–
22, Figs. 1–4. We do not reproduce that description here.
Discussion
We agree with Appellant’s arguments that: 1) Moulzolf neither
teaches nor suggests a device having its lower surface bonded to the mount
substrate with adhesive, as required by independent claims 1 and 6; and
2) the Examiner has not provided sufficient rationale for combining Chen’s
side surface roughness features with Moulzolf to arrive at claims 1 and 6.
We, therefore, reverse the Examiner’s rejections of independent claims 1
and 6, and claims 7 and 8 (which depend from claims 1 and 6, respectively).
1. A Device Having its Lower Surface Bonded to the Mount Substrate
with Adhesive
Moulzolf relates to systems and methods for attaching a device to a
substrate in a manner so that the device does not become dislodged from the
substrate in variable, potentially harsh conditions. Moulzolf ¶ 3.
Specifically, Moulzolf explains that the device and substrate may each have
a different coefficient of thermal expansion, which can cause thermal
expansion stresses leading to device performance degradation or failure in
an environment with large temperature variations. Id. ¶¶ 10, 24, 29.
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Moulzolf therefore proposes attaching the device to the substrate using
retainers in which there is a gap between the device and at least one retainer,
the gap allowing the device to freely expand relative to the retainers in
response to changes in temperature. Id. ¶¶ 10, 29. Figure 11 of Moulzolf,
reproduced below, is illustrative.

Figure 11 is a side elevation view of device 10 movably attached to
substrate 20. Moulzolf ¶ 23, Fig. 11. As shown in Figure 11, device 10 is
disposed on the bottom of substrate 20, moveably held by retainers 33 and
44. Id. at Fig. 11. Figure 11 shows gap 850 between device 10 and
substrate 20. Id.
As argued by Appellant, it is clear from Figure 11 that the claimed
device—i.e., device 10 in Moulzolf—is not bonded to the mount substrate—
i.e., substrate 20 in Moulzolf—with adhesive. Appeal Br. 8–11. Rather than
a bond formed with adhesive, there is a gap between device 10 and
substrate 20. Moulzolf, Fig. 11 (gap 850). Id. at 8–9 (Appellant explaining
that “the gap allows the device to move freely relative to the retainer and
substrate” and, therefore, “the device in Moulzolf is explicitly intended to
NOT be bonded to [] the substrate”). The Examiner finds, nonetheless, that
Figure 11 of Moulzolf teaches the claimed limitation. In so doing, the
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Examiner treats retainers 33 and 44 as the claimed “adhesive” because these
retainers can be made of adhesive material or thermoset, such as epoxy.
Ans. 3. We do not find this reasoning persuasive because, as Appellant
points out, the retainers (even if made with epoxy) are cured before coming
into contact with device 10 and, therefore, are not used to bond device 10 to
substrate 20. Reply Br. 3. The Examiner’s finding that the term “bonded”
does not preclude movement between two surfaces, even if we were to
agree, does not alter our decision. Ans. 3–4. We agree with Appellant that
because the retainers in Moulzolf, when formed of adhesive material, are
cured, they are not used to bond device 10 to substrate 20. Reply Br. 3.
We note that even if we were to adopt the Examiner’s view that
retainers 33 and 44 bond device 10 to substrate 20, Moulzolf at best would
show bonding the side surfaces of the device to the mount substrate, because
it is the device’s sides that contact retainers 33 and 44. Moulzolf, Fig. 11;
see also Ans. 4 (Fig. 11, as marked-up by the Examiner, identifies the side
surfaces of device 10 as being in contact with “adhesive”). This would not
satisfy claims 1 and 6, which require bonding the lower surface of the device
to the mount substrate with adhesive.
For the foregoing reasons, we disagree with the Examiner’s finding
that Moulzolf teaches or suggests a device having its lower surface bonded
to the mount substrate with adhesive, as recited in independent claims 1
and 6.
2. Rationale to Combine Surface Roughness Characteristics of Chen
with Moulzolf
The Examiner acknowledges that Moulzolf does not teach or suggest
the limitation “wherein a surface roughness of a side surface upper portion
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of a side surface of the device is lower than that of a side surface lower
portion of the side surface of the device,” as recited in claim 1, and the
similarly recited limitation in claim 6. Final Act. 3, 5. For this limitation,
the Examiner relies on Chen. Id. Chen discloses a semiconductor device,
namely a light emitting diode (LED) chip, wherein the lower portion of the
side surface is rougher than the upper portion of the side surface. Chen
Fig. 4. Specifically, with regard to substrate 230 of LED chip 200, lower
region 204 and middle region 206 have a non-smooth side surface (i.e., non-
smooth surface 224), and upper region 208 has a smooth side surface. Id.
¶¶ 8, 34, 38. Chen explains that the benefit of variable surface roughness is
to improve overall luminance of the LED, stating that “making the non-
smooth surface at a side surface of the substrate at least partially exposed
from the heat dissipation base, the light extraction efficiency of the LED
chip may be increased.” Id. ¶ 24; see also ¶ 40 (describing the different light
paths of light emitted by active layer 214 of the LED chip as the light hits
side surface regions 204, 206, and 208).
Appellant argues that the Examiner has not provided a motivation to
combine Chen’s use of different surface roughness for upper and lower side
portions of a device with Moulzolf. Appeal Br. 12–14. We agree. In
rejecting claims under 35 U.S.C. § 103, the Examiner’s obviousness
rejection must be based on:
“some articulated reasoning with some rational underpinning to
support the legal conclusion of obviousness” . . . . [H]owever,
the analysis need not seek out precise teachings directed to the
specific subject matter of the challenged claim, for a court can
take account of the inferences and creative steps that a person
of ordinary skill in the art would employ.

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KSR Int’l. Co. v. Teleflex, Inc., 550 U.S. 398, 418 (2007) (quoting In re
Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006)). Here, the Examiner has not
provided articulated reasoning with some rational underpinning to support
the conclusion of obviousness.
The Examiner identifies features taught in Chen, then concludes it
would have been obvious to modify Moulzolf’s device to include these
features “for forming the roughness side surface of the device in order to
provide a different application of the device.” Final Act. 3. The Examiner’s
reasoning, i.e., to provide a different application, is insufficient because the
Examiner does not provide a rational underpinning for providing the
different application. As argued by Appellant, the rationale of “‘providing a
different application of a device’ is not a sufficient motivation to modify a
reference” and “[i]f the Examiner’s ‘rationale’ . . . were accepted as a
sufficient rationale for combining two references, then virtually any two
references would be permissible.” Appeal Br. 13.
As Appellant further points out, the rationale in Chen of providing a
smoother upper side surface and rougher lower side surface is to provide
improved light emission from an LED device that is partially embedded in a
substrate. Id. (citing Chen ¶¶ 5–8). The Examiner identifies nothing in
Moulzolf suggesting an LED chip embedded in a substrate. Id. at 13.
Indeed, as we discussed above in the previous section, Moulzolf is not even
bonded to the substrate. Accordingly, we fail to discern, and the Examiner
has not provided, a reason to use Chen’s variable side surface roughness in
Moulzolf.
The Examiner’s Answer responds that Appellant has improperly
argued bodily incorporation, but we disagree with this characterization of
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Appellant’s argument. Ans. 5. Appellant’s argument is not that Chen’s
variable side roughness cannot be incorporated into Moulzolf, but that the
Examiner has not provided sufficient motivation to do so. Appeal Br. 12–
14.
The Examiner also provides the following statement:
Regarding the motivation of “different application”, the
Examiner meant the device instead of smooth side surface can
replace by the surface roughness of the side surface disclosed by
Chen. The amount of adhesive on the roughness surface is more
comparing to the amount of adhesive on the smooth surface;
therefore, increasing the reliability and contact surface between
the device and the mounting structure.
Ans. 6. This statement is not clear as to how Moulzolf is being
modified, and therefore fails to support the Examiner’s conclusion of
obviousness.
The Examiner also asserts, without explanation, that modifying the
device in Moulzolf to include rougher lower side surface portions would not
change the operation of the device or its intended purpose. Ans. 7.
However, the Examiner does not provide underlying supporting evidence
and/or reasoning to support this assertion. Moreover, even if we were to
assume arguendo, without deciding, that modifying Moulzolf would not
change the device’s operation or intended purpose, this would not amount to
a rationale or motivation to combine. Still lacking is a reason to make the
modification.
For the foregoing reasons, the Examiner has not provided sufficient
articulated reasoning with some rational underpinning to support the legal
conclusion of obviousness.
Appeal 2020-006239
Application 14/766,414
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CONCLUSION
The Examiner’s rejections are reversed.
More specifically, we do not sustain the rejections of:
Claims 1, 2, and 6 under 35 U.S.C. § 103 as unpatentable over the
combination Moulzolf, Chen, and Engelhardt; and
Claims 7 and 8 under 35 U.S.C. § 103 as unpatentable over the
combination of Moulzolf, Chen, Engelhardt, and Kang.
DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
References/Basis Affirmed Reversed
1, 2, 6 103 Moulzolf, Chen,
Engelhardt
1, 2, 6
7, 8 103 Moulzolf, Chen,
Engelhardt, Kang
7, 8
Overall
Outcome
1, 2, 6–8
REVERSED