Ex Parte Sueoka

Patent Trial and Appeal Board

Mar 30, 2016

13423552 (P.T.A.B. Mar. 30, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/423,552 03/19/2012
48915 7590 04/01/2016
CANTOR COLBURN LLP-IBM YORKTOWN
20 Church Street
22nd Floor
Hartford, CT 06103
FIRST NAMED INVENTOR
Kuniaki Sueoka
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.
JP920110020US 1 1004
EXAMINER
STONER, KILEY SHAWN
ART UNIT PAPER NUMBER
1735
NOTIFICATION DATE DELIVERY MODE
04/01/2016 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):
usptopatentmail@cantorcolbum.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte KUNIAKI SUEOKA 1
Appeal 2014-0061172
Application 13/423,552
Technology Center 1700
Before CHUNG K. PAK, GEORGE C. BEST, and JULIA HEANEY,
Administrative Patent Judges.
PAK, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on an appeal under 35 U.S.C. § 134(a) from the
Examiner's decision3 rejecting claims 1-3, 6, 8, and 9, which are all of the claims
1 The real party in interest is said to be International Business Machines
Corporation. Appeal Brief filed December 27, 2013 ("App. Br.") at 1.
2 Although Appellant states that "[t]here are no related appeals ... known at this
time to the Appellant[] ... that will directly affect, or be directly affected by, or
have a bearing upon the Board's Decision in this appeal," App. Br. 2, we note that
the claims of Appeal 2014-004751 (Application 13/561,460, assigned to the same
real party in interest) recite using the same pyrolytic graphite sheet as the high
thermal conductive material of a tool head for bonding silicon chips, with the same
thickness range, as the claims in this appeal. We also note that the Appeal Brief in
that proceeding raises the same substantive issues presented in this appeal.
Appeal2014-006117
Application 13/423,552
pending in the above-identified application. Claims 4, 5, and 7 have been
canceled. We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
STATEMENT OF THE CASE
The subject matter on appeal "relates to bonding of semiconductor silicon
(Si) chips[.]" Spec. 1, ,-i 3. Details of the appealed subject matter are recited in
illustrative claim 1, 4 which is reproduced below from the Claims Appendix of the
Appeal Brief:
1. An apparatus, comprising:
a tool head configured for bonding to establish 100 or more electrical
and mechanical connections between a silicon chip having a thickness of
about 50 microns (µm) or smaller and a substrate, wherein 100 or more
solder bumps set on a plurality of contacts on the silicon chip or a plurality
of contacts on the substrate are melted by heating between the plurality of
contacts of the silicon chip and the substrate, and wherein the melted solder
bumps are solidified by cooling using forced convection of air flowing from
around the silicon chip;
the tool head comprising a pulse heater and a pyrolytic graphite sheet
configured to be used in direct contact with the silicon chip, and having a
thickness between about 75 µm and 125 µm so as to have a conformal
property that achieves a high thermal conductivity and minimizes
mechanical stress between the tool head and the silicon chip.
App. Br. 14 (emphasis added).
3 Final Action mailed August 1, 2013 ("Final Act.") at 1-11; the Examiner's
Answer mailed February 26, 2014 ("Ans.") at 2-3; and App. Br. 3.
4 Appellant only relies upon the limitations of claim 1 for the patentability of the
subject matter recited in the claims on appeal, namely claims 1-3, 6, 8, and 9.
App. Br. 6-13. Therefore, for purposes of this Appeal, we limit our discussion to
claim 1. 37 C.F.R. § 41.37(c)(l)(iv) (2012).
2
Appeal2014-006117
Application 13/423,552
The Examiner has maintained the following grounds of rejection:
1. Claims 1-3, 6, 8, and 9 under 35 U.S.C. § l 12(b) or 35 U.S.C. § 112,
second paragraph (pre-AIA), as being indefinite for failing to particularly
point out and distinctly claim the subject matter which the applicants regard
as their invention;
2. Claims 1, 2, and 9 under 35 U.S.C. § 103(a) as unpatentable over the
combined teachings of the admitted prior art, 5 Heat Sinking Material, 6 and
Kubota· 7
'
3. Claim 3 under 35 U.S.C. § 103(a) as unpatentable over the combined
teachings of the admitted prior art, Heat Sinking Material, Kubota, and
Silicon Adhesives; 8 and
4. Claims 6 and 8 under 35 U.S.C. § 103(a) as unpatentable over the combined
teachings of the admitted prior art, Heat Sinking Material, Kubota, and
Morita.9 Final Act. 1-11; Ans. 2-3.
5 Appellant's admission at paragraphs 7, 34, 35, 36, 37, and 58-62 of the
Specification ("the admitted prior art").
6 Pyrolytic Graphite Sheet (PGS) Heat Sinking Material-Panasonic, http://www.
panasonic. com/industrial/ electronic-components/protection/heat-sinking-
material. aspx, Feb. 3, 2010 ("Heat Sinking Material").
7 US 2002/0140094 A 1 published in the name of Kubota et al. on October 3, 2002
("Kubota").
8 Silicone Adhesive and Sealants-Dow Coming,
h11Q_~LL:'!Y~YW:_d_myf_m:ning,_9-_mnf~QJJJ_~_n1Hm:nLim:n_§~_9:li!nt§f, June 2 009 ("Silicone
Adhesive").
9 US 5,667,129 issued in the name of Morita et al. on September 16, 1997
("Morita").
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Application 13/423,552
DISCUSSION
Upon consideration of the evidence on this appeal record in light of the
respective positions advanced by the Examiner and Appellant, we find no
reversible error in the Examiner's rejections of claims 1-3, 6, 8, and 9 under
35 U.S.C. §§ 112 and 103(a). Accordingly, we sustain the Examiner's§§ 112 and
103(a) rejections of the above claims for the reasons set forth in the Final Action
and the Answer. We add the following primarily for emphasis.
35 U.S.C. § 112
We initially note that Appellant does not contest the Examiner's
determination that the term "high" recited in independent claims 1 and 6 is
indefinite. Compare Final Act. 2 and Ans. 3 with App. Br. 6-13 and Reply Brief
filed April 22, 2014 ("Reply Br.") at 2-4. Accordingly, we summarily affirm the
Examiner's rejection of claims 1-3, 6, 8, and 9 under 35 U.S.C. § l 12(b) or 35
U.S.C. § 112, second paragraph (pre-AIA), as being indefinite.
35 U.S.C. § 103(a)
Appellant does not dispute the Examiner's finding that the admitted prior art
reveals that:
[A Jn apparatus (figure 1 C), comprising: a tool head ( 104) configured
for bonding to establish 100 or more electrical and mechanical
connections between a silicon chip having a thickness of about 50
microns (µm) or smaller and a substrate, wherein 100 or more solder
bumps set on a plurality of contacts on the silicon chip ... are melted
by heating between the plurality of contacts of the silicon chip and the
substrate, and wherein the melted solder bumps are solidified by
cooling using forced convection of air flowing from around the silicon
chip; [and] the tool head ( 104) [comprising a heating means and a
high thermal conductive material] configured to be used in direct
contact with the silicon chip (figure IC; and paragraphs 34-37 of [the
Specification] ... ). ([Emphasis original)].
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Application 13/423,552
Compare Final Act. 4 with App. Br. 6-13 and Reply Br. 2--4. Nor does Appellant
dispute the Examiner's determination that one of ordinary skill in the art would
have been led to use the pulse heater of Kubota's tool head as the heating means
for the tool head taught by the admitted prior art. Compare Final Act. 5 with App.
Br. 6-13 and Reply Br. 2--4.
Rather, Appellant contends that the Examiner has erred in determining that
one of ordinary skill in the art would have been led to employ the pyrolytic
graphite sheet having an excellent thermal conductivity taught by Heat Sinking
Material as the high thermal conductive material of the tool head suggested by the
admitted prior art and Kubota. App. Br. 6-13 and Reply Br. 2--4. In support of
this contention, Appellant argues that "in addition to having good thermal
conductivity properties, one skilled in the art at the time of the invention would
[have] also look[ ed] to the use of a tool head material having a CTE [ (a coefficient
of thermal expansion)] that is very close to that of silicon" because "[a]s is known
in the art the greater the mismatch between the CTE of different layers, the greater
the mechanical stress generated therebetween under elevated temperature
conditions such as during bonding for example." App. Br. 11. According to
Appellant, the pyrolytic graphite sheet taught by Heat Sinking Material has a CTE
of 9.3 x 10-7 /Kin plane direction, which is a mismatch with respect to that of
silicon ( 4.2 x 1 o-6 /°C), unlike a conventional aluminum nitride tool head material
(AIN) having a CTE of 5.0 xl0-6, /°C, which is very close to that of silicon
(4.2 x 10-6 /°C). App. Br. 11-12 referring to Spec. ,-i,-i 37 and 59-62; Reply Br. 2-
3.
However, we find Appellant's arguments unpersuasive for the reasons set
forth by the Examiner in the Final Action and the Answer. First, as pointed out by
the Examiner, Appellant does not identify any objective evidence of record to
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Application 13/423,552
support the argument that a CTE match (or mismatch) would have been important
to a person of ordinary skill in the art seeking to select a high thermal conductive
material as the high thermal conductive material of a tool head used for bonding
silicon chips. Ans. 6. Appellant's mere attorney argument cannot take the place of
objective evidence. See In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984).
Secondly, the Examiner has found, and Appellant does not dispute, that the
admitted prior art describes using high thermal conductive materials other than
AIN as a tool head material. Compare also Ans. 4-5 with App. Br. 6-13 and
Reply Br. 2--4; see also Spec. iii! 7 and 35. Appellant also does not argue that the
other conventional high thermal conductive tool head materials taught by the
admitted prior art are also required to have CTEs which are close to that of silicon.
App. Br. 6-13 and Reply Br. 2--4. In fact, the Specification states that the use of
graphite, diamond coated films, and the like as high thermal conductive materials
for a chip bonding or mounting tool was known at the time of the invention. Spec.
iJ 7. Thus, we find that Appellant has not identified reversible error in the
Examiner's determination that "it would have been obvious to one of ordinary skill
in the art to substitute the high thermal conductivity pyrolytic graphite sheet of
Heat Sinking Material for the high thermal conductive material of AAP A [ (the
admitted prior art),]" with a reasonable expectation of successfully imparting a
predictable result, i.e., a desired high thermal conductivity. 10
10 Consistent with the above teachings of the admitted prior art, Kubota also
implies that high conductive tool head materials need not have CTEs near that of
silicon. Kubota iJ 10. Specifically, Kubota discloses that an epoxy under-fill
normally applied between the active surface of the chip and the top surface of the
substrate "helps to more evenly distribute stress caused by thermally induced
strains due to the differences in coefficients of thermal expansion (CTE) between
the chip and substrate across the entire surface of the chip and substrate." Id.
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Application 13/423,552
Appellant also contends that Heat Sinking Material does not mention that its
pyrolytic graphite sheet has a thickness of about 75 µm to 125 µm so as to have a
conformal property that achieves a desired high thermal conductivity and reduced
mechanical stress between the tool head and the silicon chip as required by claim
1. App. Br. 12. However, we are not persuaded by this contention.
The Examiner has found, and Appellant does not dispute, that "[ s ]ince the
amount of heat passed by a pyrolytic graphite sheet in unit time depends on its
thickness, the thickness of the pyrolytic graphite sheet is a [known] result effective
variable." Compare Final Act. 5 with App. Br. 6-13. Consequently, we find no
reversible error in the Examiner's determination that one of ordinary skill in the art
would have been led to optimize the thickness of the pyrolytic graphite sheet
taught by Heat Sinking Material to provide a desired high thermal conductivity,
i.e., a conformal property, useful for the head tool suggested by the admitted prior
art and Kubota. In re Boesch, 617 F.2d 272, 276 (CCPA 1980)("[D]iscovery of an
optimum value of a result effective variable ... is ordinarily within the skill of the
art.").
In any event, we note that Appellant's Specification recognizes the pyrolytic
graphite sheet disclosed in Heat Sinking Material has a thickness of 50 µm to 150
µm. See Spec. Spec. ,-i,-i 58- 62 (Heat Sinking Material's pyrolytic graphite sheet
commercially sold by Panasonic has a thickness of0.10± 0.05 mm (50 µm to 150
µm)). This range overlaps Appellant's recited thickness range of between about 75
µm and 125 µm and, therefore, renders it prima facie obvious. In re Peterson, 315
F.3d 1325, 1329-30 (Fed. Cir. 2003) ("In cases involving overlapping ranges, we
and our predecessor court have consistently held that even a slight overlap in range
establishes a primafacie case of obviousness."). Nevertheless, Appellant has not
shown that the particular claimed thickness of the pyrolytic graphite sheet of a tool
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Appeal2014-006117
Application 13/423,552
head for bonding silicon chips is critical, e.g., achieves unexpected results relative
to the prior art range. Id. at 1330.
Appellant argues that utilizing the pyrolytic graphite sheet as the heat
transfer layer provides an additional advantage over AlN: its confonnability
allows for minimizing mechanical stress between the tool head and the silicon
chip. App. Br. 12. However, this argument is not well taken.
As indicated supra, the collective teachings of the admitted prior art, Heat
Sinking Material, and Kubota provide at least one reason contemplated by
Appellant (the need for an enhanced high thermal conductivity, one of the asserted
conformability properties) for employing a pyrolytic graphite sheet having an
optimum thickness as the high thermal conductive material of the tool head
suggested by the admitted prior art and Kubota. Moreover, Heat Sinking Material,
like Appellant, describes its pyrolytic graphite sheet as a "sheet with high thermal
conductivity and the ability to flex." Heat Sinking Material 1; Spec. ,-i 49. Thus,
an additional conformability property, i.e., reduced mechanical stress between the
tool head and the silicon chip recited in claim 1 would have naturally flowed from
following the suggestion of using Heat Sinking Material's pyrolytic graphite sheet
having a desired high thermal conductivity as the high thermal conductive material
of a tool head, 11 or would have been reasonably expected by one of ordinary skill
in the art due to the enhanced thermal transfer properties associated with using
11 Ans. 9; Ex parte Obiaya, 227 USPQ 58, 60 (BPAI 1985)("The fact that appellant
has recognized another advantage which would flow naturally from following the
suggestion of the prior art cannot be the basis for patentability when the differences
would otherwise be obvious."
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Application 13/423,552
Heat Sinking Material's pyrolytic graphite sheet having a desired high thermal
conductivity. 12
Further, Appellant contends that the inventor discovered the source of a
problem, i.e., recognizing a temperature decrease starting from a peripheral portion
of a silicon chip subjected to cooling air so that the solidification of the solder
bumps starts and advances from the peripheral portion of the silicon chip, and this
discovery had led the inventor to the solution of using a highly thermally
conductive pyrolytic graphite sheet to address this non-uniform cooling. App. Br.
12- 13 referring to Spec. ,-i,-i 40- 44 and citing In re Sponnoble, 405 F.2d 578
(CCPA 1969). 13 However, we do not find Appellant's contention persuasive.
First, the Supreme Court of the United States stated that it was error to hold
"that courts and patent examiners should look only to the problem the [applicants
were] trying to solve." KSR Int'! Co. v. Teleflex Inc., 550 U.S. 398, 420 (2007).
The Supreme Court emphasized that "[t]he question is not whether the
combination was obvious to the [the applicants] but whether the combination was
obvious to a person with ordinary skill in the art." Id. As indicated supra, the
collective teachings of the admitted prior art, Heat Sinking Material, and Kubota
would have led one of ordinary skill in the art to employ Heat Sinking Material's
pyrolytic graphite sheet having an optimum thickness as the high thermal
conductive material of the tool head suggested by the admitted prior art and
Kubota, with a reasonable expectation of successfully improving high thermal
conductivity. In re Beattie, 974 F.2d 1309, 1312 (Fed. Cir. 1992) ("As long as
12 In re Langi, 759 F.2d 887, 897 (Fed. Cir. 1985) "[A] reasonable expectation of
success, not absolute predictability" supports a conclusion of obviousness.
13 "[A] patentable invention may lie in the discovery of the source of a problem."
Sponnoble, 405 F.2d at 585 (emphasis added).
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Application 13/423,552
some [reason,] motivation or suggestion to combine the references is provided by
the prior art taken as a whole, the law does not require that the references be
combined for the reasons contemplated by the inventor.").
Secondly, Appellant's "discovery of the source of a problem" relating to a
temperature decrease starting from a peripheral portion of a silicon chip subjected
to cooling air, thus, causing the solidification of the solder bumps starting and
advancing from the peripheral portion of the silicon chip would have been readily
noticeable to one of ordinary skill in the art by simple observation of the melting
rate of solder bumps and/or would have been expected by one of ordinary skill in
the art based on the location of cooling means. See, e.g., In re Ludwig, 353 F.2d
241, 244 ( CCP A 1965) (explaining that discovery of a problem readily noticeable
by one skilled in the art does not impart patentability). Thus, using a commercially
available pyrolytic graphite sheet having a thickness that provides a desired high
thermal conductivity as the high thermal conductive material of a tool head as
suggested by the collective teachings of the admitted prior art, Heat Sinking
Material, and Kubota would have also been reasonably expected to address this
uneven or non-uniform cooling due the enhanced thermal transfer properties
associated with Heat Sinking Material's commercially available pyrolytic graphite
sheet having a desired high thermal conductivity.
Accordingly, we find no reversible error in the Examiner's decision rejecting
claims 1-3, 6, 8, and 9 under 35 U.S.C. § 103.
ORDER
In view of the foregoing, the decision of the Examiner to reject claims 1-3,
6, 8, and 9 under 35 U.S.C. §§ 112 and 103(a) is AFFIRMED.
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Application 13/423,552
No time period for taking any subsequent action in connection with this
appeal may be extended under 37 C.F.R. § l.136(a)(l )(iv).
AFFIRMED
11