Ex Parte Nagasawa et al

Board of Patent Appeals and Interferences

Jan 26, 2012

10484454 (B.P.A.I. Jan. 26, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte HIROSHI NAGASAWA, KAORI KAGOSHIMA,
NAOAKI OGURE, MASAYOSHI HIROSE, and YUSUKE CHIKAMORI
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Appeal 2009-014359
Application 10/484,454
Technology Center 2800
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Before MAHSHID D. SAADAT, JEFFREY S. SMITH, and
JASON V. MORGAN, Administrative Patent Judges.

MORGAN, Administrative Patent Judge.

DECISION ON APPEAL
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STATEMENT OF THE CASE
Introduction
This is an appeal under 35 U.S.C. § 134(a) from the Examiner’s final
rejection of claims 16 and 30 – 38. We have jurisdiction under 35 U.S.C.
§ 6(b).
We affirm.
Invention
The invention relates to a bonding material and a bonding method
which effect bonding between parts by using composite metallic nano-
particles (Spec. 1, ll. 5 – 10). Claim 16 is directed to a bonding method in
which (1) a bonding material containing composite metallic nano-particles is
heated to bond first and second parts together to obtain a bonded member
and (2) the same bonding material is heated to bond the bonded member and
a third part.
Exemplary Claim
16. A bonding method comprising:
allowing a bonding material to be present between and in
contact with a first part and a second part to be bonded,
the bonding material containing composite metallic nano-
particles each having such a structure that a metal core of
a metal particle having a diameter of 0.5 nm to 100 nm is
combined and coated with an organic material;
heating the bonding material at a temperature which is
equal to or higher than the decomposition initiating
temperature of the organic material, but lower than the
melting temperature of the metal in a bulk state, so as to
release the organic material from the metal core of the
bonding material present between the first part and the
second part and to sinter the metal core, thereby forming
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a bulk metal and bonding the first part and the second
part together to obtain a bonded member;
allowing the same bonding material to be present
between and in contact with the obtained bonded member
and a third part; and then
heating the same bonding material at a temperature
which is equal to or higher than the decomposition
initiating temperature of the organic material, but lower
than the melting temperature of the metal in a bulk state,
so as to release the organic material from the metal core
of the bonding material present between the bonded
member and the third part and to sinter the metal core
without melting the bulk metal, thereby bonding the
bonded member and the third part.
Evidence Examiner Relies Upon
Hiruta US 5,998,861 Dec. 7, 1999
Fukunaga US 2001/0006455 A1 Jul. 5, 2001
Aoki US 6,483,195 B1 Nov. 19, 2002
Chheang US 2003/0100654 A1 May 29, 2003
Examiner’s Rejections
The Examiner rejects claims 16, 30 – 32, 36, and 37 under 35 U.S.C.
§ 103(a) as being unpatentable over Hiruta and Fukunaga (Ans. 3 – 6).
The Examiner rejects claims 33 – 35 under 35 U.S.C. § 103(a) as
being unpatentable over Hiruta, Fukunaga, and Chheang (Ans. 6 – 7).
The Examiner rejects claim 38 under 35 U.S.C. § 103(a) as being
unpatentable over Hiruta, Fukunaga, and Aoki (Ans. 7).
ISSUE
Did the Examiner err in finding that the combination of Hiruta and
Fukunaga teaches the recitations of claim 16?
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ANALYSIS
Claim 16
Claim 16 recites a bonding method comprising (1) “allowing a
bonding material to be present between and in contact with a first part and a
second part to be bonded, the bonding material containing composite
metallic nano-particles each having . . . a metal core . . . coated with an
organic material”; (2) “heating the bonding material at a temperature which
is equal to or higher than the decomposition initiating temperature of the
organic material, but lower than the melting temperature of the metal in a
bulk state”; (3) “allowing the same bonding material to be present between
and in contact with the obtained bonded member and a third part”; and (4)
“heating the same bonding material at a temperature which is equal to or
higher than the decomposition initiating temperature of the organic material,
but lower than the melting temperature of the metal in a bulk state.”
The Examiner finds that Hiruta teaches the claimed steps, except that
Hiruta’s bonding material does not contain “composite metallic nano-
particles” (Ans. 3 – 4). The Examiner relies on Fukunaga as teaching a
bonding material containing “composite metallic nano-particles” and
bonding by heating the bonding material “at a temperature which is equal to
or higher than the decomposition initiating temperature of the organic
material, but lower than the melting temperature of the metal in a bulk state”
(Ans. 4 – 5). The Examiner concludes that it would have been obvious to an
artisan to combine the teachings of Hiruta and Fukunaga “to make an
improved low-cost and reliable connection” (Ans. 5).
Appellants contend that Hiruta does not teach a bonding material that
contains composite metallic nano-particles or a bonding method comprising
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heating bonding material at a temperature lower than the melting
temperature of the bonding material’s metal (Br. 5). Appellants also contend
that Fukunaga does not teach (1) bonding first and second parts together by
heating a bonding material located between the parts to create a bonded
member and (2) bonding the bonded member with a third part by heating the
same bonding material located between the bonded member and third part
(Br. 5 – 6).
Appellants cannot show error in the Examiner’s rejection by attacking
Hiruta and Fukunaga separately when the rejection is based on the combined
teachings of Hiruta and Fukunaga. See In re Keller, 642 F.2d 413, 426
(CCPA 1981). Hiruta, not Fukunaga, teaches bonding first and second parts,
large scale integrated circuit chip 10 and carrier chip 11, by heating a
bonding material, ball bumps 44, located between the two parts to form a
bonded member, semiconductor device 150 (Hiruta col. 3, ll. 45 – 57 and
col. 7, ll. 4 – 10; figs. 6 and 18). Hiruta further teaches bonding the
semiconductor device 150 with a third part, printed circuit board 200, by
heating a bonding material, ball electrodes 38, located between the
semiconductor device 150 and the third part (Hiruta col. 10, ll. 4 – 9; fig.
18). The bonding material in both bonding steps is the same, having the
same tin-lead alloy composition (Hiruta col. 7, ll. 11 – 14).
Fukunaga, not Hiruta, teaches a bonding material containing
composite metallic nano-particles: compound metallic ultra-fine particle 14
(Fukunaga ¶ [0037]; fig. 1A). Fukunaga also teaches bonding two parts,
semiconductor 20 and circuit board 40, with a material containing composite
metallic nano-particles, metallic paste balls 52 (Fukunaga ¶¶ [0052] and
[0059]; fig. 7E). This bonding takes effect with a low temperature heat
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treatment (Fukunaga ¶ [0059]), taking advantage of the low temperature
(“considerably lower . . . than the melting point of the metal”) needed to
bond the metallic core of the nano-particles (Fukunaga ¶ [0039]).
An artisan of ordinary skill would have appreciated that Fukunaga’s
bonding material containing composite metallic nano-particles could replace
Hiruta’s tin-lead alloy. Such an artisan would have further realized that
bonding would take effect at a low temperature, as taught by Fukunaga,
rather than at the high temperature used when bonding using Hiruta’s tin-
lead alloy. Thus, we agree with the Examiner that the combination of Hiruta
and Fukunaga teaches or suggests the claimed invention.
Appellants also contend that it would not have been obvious to an
artisan to combine Hiruta and Fukunaga because “it appears that the
Examiner is simply relying on impermissible hindsight to provide the
necessary motivation” (Br. 7). However, we are persuaded that the
Examiner’s prima facie case of obviousness does not rely on ex post
reasoning. See KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398, 421 (2007).
Fukunaga teaches that bonding with composite metallic nano-particles
results in “a highly stable, low-cost, high reliability electrical connection
with no risk of short-circuiting adjacent electrodes of even a narrow pitch”
(Fukunaga ¶ [0061]) (emphasis added). This teaching supports the
Examiner’s reasoning (Ans. 5). Thus, the Examiner’s reasoning has a
rational underpinning based on knowledge that would have been available to
an artisan of ordinary skill at the time of the invention.
Appellants further contend “a modification of the Hiruta reference as
suggested by the Examiner would significantly change the principle of
operation of the Hiruta reference, as the soldering of the Hiruta reference
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cannot be performed without heating the bonding material to a sufficiently
high temperature for melting and soldering” (Br. 7). However, we are not
convinced that high temperature melting and soldering is the principle of
operation in Hiruta. High temperature melting and soldering is merely an
aspect of tin-lead alloy bonding. Replacing Hiruta’s tin-lead alloy with a
bonding material comprising Fukunaga’s composite metallic nano-particles
would allow for bonding at the lower temperature taught by Fukunaga
without changing the operational principle of Hiruta related to miniaturizing
a semiconductor device having a ball grid array (see Hiruta col. 2, ll. 51 –
54).
For the above reasons, we agree with the Examiner that the claimed
invention would have been obvious in light of the teachings of Hiruta and
Fukunaga. Accordingly, we find that the Examiner did not err in rejecting
claim 16 under 35 U.S.C. § 103(a).
Claims 30 – 38
Appellants provide no additional arguments with respect to these
claims, except to contend that Chheang and Aoki do not cure the alleged
deficiencies of Hiruta and Fukunaga (Br. 7 – 8). Accordingly, for the reasons
discussed above, we find that the Examiner did not err in rejecting claims 30
– 38 under 35 U.S.C. § 103(a).
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DECISION
We affirm the Examiner’s decision rejecting claims 16 and 30 – 38.
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)(iv).

AFFIRMED

ELD