Ex parte Eckhard Wolfgang et al.

Board of Patent Appeals and Interferences

Jul 31, 1997

08008734 (B.P.A.I. Jul. 31, 1997)

Application for patent filed January 25, 1993.1
1
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today (1)
was not written for publication in a law journal and (2) is not
binding precedent of the Board.
Paper No. 19
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte ECKHARD WOLFGANG
and REINHOLD KUHNERT

_____________
Appeal No. 95-0543
Application 08/008,7341
______________
HEARD: July 14, 1997
_______________
Before JERRY SMITH, LEE and CARMICHAEL, Administrative Patent
Judges.
JERRY SMITH, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on the appeal under 35 U.S.C. § 134
from the examiner's rejection of claims 1, 3, 8-10, 16 and 17.
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Application 08/008,734
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Claims 2, 6, 7 and 11 have been cancelled. Claims 4, 5 and 12-15
have been allowed by the examiner.
The claimed invention pertains to a structure for
eliminating heat from a semiconductor chip in a semiconductor
module.
Representative claim 1 is reproduced as follows:
1. A semiconductor module, comprising:
a semiconductor chip;
means affixed to said semiconductor chip for
eliminating heat from said semiconductor chip;
an electrically insulating and thermally conducting
layer of crystalline carbon between said semicon-
ductor chip and said means for eliminating heat;
at least one intermediate layer between said semicon-
ductor chip and said means for eliminating heat;
and
connecting layers of silver between said semiconductor
chip and said means for eliminating heat, wherein
only one of said connecting layers is between said
means for eliminating heat and said electrically
insulating and thermally conducting layer.
The examiner relies on the following reference:
Potter 3,872,496 Mar. 18, 1975

Claims 1 and 8 stand rejected under 35 U.S.C. § 102(b) as
being anticipated by the disclosure of Potter. Claim 3 stands
rejected alternatively under 35 U.S.C. § 102(b) or § 103 as being
anticipated by or unpatentable over Potter. Claims 9, 10, 16 and
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17 stand rejected under 35 U.S.C. § 103 as being unpatentable
over the teachings of Potter.
Rather than repeat the arguments of appellants or the
examiner, we make reference to the brief and the answer for the
respective details thereof.
OPINION
We have carefully considered the subject matter on
appeal, the rejections advanced by the examiner and the evidence
of anticipation and obviousness relied upon by the examiner as
support for the rejections. We have, likewise, reviewed and
taken into consideration, in reaching our decision, the
appellants' arguments set forth in the brief along with the
examiner's rationale in support of the rejections and arguments
in rebuttal set forth in the examiner's answer.
It is our view, after consideration of the record before
us, that the disclosure of Potter fully meets the invention as
recited in claims 1 and 3. We reach the opposite conclusion with
respect to claim 8. We are also of the view that the teachings
of Potter and the level of skill in the particular art would have
suggested to one of ordinary skill in the art the obviousness of
the invention as set forth in claims 9 and 10. We reach the
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Application 08/008,734
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opposite conclusion with respect to claims 16 and 17.
Accordingly, we affirm-in-part.
We consider first the rejection of claim 1 under 35
U.S.C. § 102(b) as being anticipated by the disclosure of Potter.
Anticipation is established only when a single prior art
reference discloses, expressly or under the principles of
inherency, each and every element of a claimed invention as well
as disclosing structure which is capable of performing the
recited functional limitations. RCA Corp. v. Applied Digital
Data Systems, Inc., 730 F.2d 1440, 1444, 221 USPQ 385, 388 (Fed.
Cir.); cert. dismissed, 468 U.S. 1228 (1984); W.L. Gore and
Associates, Inc. v. Garlock, Inc., 721 F.2d 1540, 1554, 220 USPQ
303, 313 (Fed. Cir. 1983), cert. denied, 469 U.S. 851 (1984).
The examiner has supported this rejection by reading
claim 1 on the Potter disclosure [answer, pages 3-4]. Appellants
argue that Potter teaches that there are four layers between the
heat sink and the diamond layer. According to appellants, this
teaching of Potter cannot meet the claim 1 recitation of “wherein
only one of said connecting layers is between said means for
eliminating heat and said electrically insulating and thermally
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conducting layer” [brief, page 6]. The examiner has responded
that appellants are not giving claim 1 the appropriate scope
based on the recitations of claim 1.
It would be appropriate to first review the teachings of
Potter as applied by the examiner. Potter teaches a crystalline
carbon (4) connected between a chip (diode 11) and a means for
eliminating heat from the chip (copper base 1). There are four
metal layers between the carbon and the chip and between the
carbon and the base which serve to bond the three components
together. Each of the bonds is made up of a chromium-gold-gold-
chromium arrangement. Potter discloses that the gold-gold bond
could also be a silver-silver bond or a bond of silver-gold
[column 3, lines 43-45]. The examiner has taken the position
that the bond between the crystalline carbon and the copper base
could be a chromium-gold-silver-chromium bond within the
teachings of Potter. Likewise, the bond between the crystalline
carbon and the chip could have one or two silver layers.
When the Potter structure is viewed in this manner, there
is one silver layer between the copper base and the carbon (layer
16 or 2) and one or more silver layers between the carbon and the
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chip (layer 7 and/or 8). In this arrangement there are two or
three silver layers, and only one of these layers is between the
carbon and the copper base. Claim 1 only refers to the
connecting layers of silver so that the presence or absence of
other
layers is not relevant to the claimed invention. The “connecting
layers of silver” would be met by the two or three silver layers
of Potter noted above, and the “only one of said connecting
layers” [of silver] would be met by the single silver layer 2 or
16.
Thus, when claim 1 is given its literal interpretation as
required by law, it is seen that the claim does in fact read on
the Potter device when appropriate ones of the gold layers are
replaced by silver layers as suggested within Potter. It is
emphasized that for purposes of reading the claim on Potter, the
chromium and gold layers of Potter are ignored. Only the silver
layers are looked at to meet the recitations of claim 1. We
agree with the examiner that Potter does disclose at least one
relationship of silver layers which would fully meet the
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invention as recited in claim 1. Therefore, we sustain the
rejection of claim 1 as anticipated by the disclosure of Potter.
Claims 9 and 10 depend from claim 1 and recite that the
insulating and conducting layer of claim 1 is polycrystalline
carbon and monocrystalline carbon, respectively. The examiner
has rejected these claims under 35 U.S.C. § 103 as unpatentable
over the teachings of Potter. According to the examiner, the
diamond disclosed in Potter is either monocrystalline or
polycrystalline carbon. The examiner provides a reasoned
analysis as to why the artisan would have found it obvious to use
either form of crystalline carbon [answer, pages 5-6].
Appellants argue that the type IIa diamond of Potter is believed
to be a monocrystalline carbon, and there is no suggestion in
Potter to use a polycrystalline carbon [brief, page 8].
Although we would have preferred that the examiner cite a
reference in support of the position that a polycrystalline
carbon would have been obvious to the artisan in view of Potter,
we nevertheless find that the record supports the examiner’s
finding of this fact. Every crystalline carbon is presumably
either monocrystalline or polycrystalline carbon. The scope of
claim 9 includes any polycrystalline carbon. Given that a
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crystalline carbon is either monocrystalline or polycrystalline,
the examiner’s position that it would have been obvious to the
artisan in 1992 to select at least one polycrystalline carbon as
a substitute for the carbon of Potter is persuasive. We note
that appellants have offered no rebuttal arguments as to the
alleged errors in the examiner’s analysis. Appellants only argue
that the carbon in Potter is not polycrystalline. This argument,
however, does not rebut the examiner’s persuasive reasoning as to
why polycrystalline carbon would have been suggested to the
artisan in 1992. Therefore, on the record before us, we agree
with the examiner that the invention of claims 9 and 10 would
have been obvious to the artisan in view of the teachings of
Potter and the state of knowledge in the art at the time this
application was filed. The rejection of claims 9 and 10 is
sustained.
We now consider the rejection of claim 3 under 35 U.S.C.
§ 102(b)/103 alternatively as being anticipated by the disclosure
of Potter or as being unpatentable over the teachings of Potter.
The examiner notes that Potter shows the features of claim 3 in
the same manner as noted for claim 1 except that Potter fails to
explicitly show the claimed “sinterable connections” [answer,
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page 5]. The examiner takes the position that the term
“sinterable” or “pressure-sintered connection” adds no additional
structure to the claimed device. Appellants argue that the
claimed pressure sintered connection of claim 3 is structurally
different than other connections and is not taught by Potter
[brief, page 7]. The examiner responds that appellants have
offered no evidence in support of this contention [answer, pages
9-10].
Claim 3 broadly recites that there is a pressure sintered
connection between each of the layers. No unusual significance
is attached to this phrase. Appellants state that “[t]he
mechanical connection between the semiconductor chip CHIP2 and
the heat elimination means W2 is subsequently effected through
the use of a method of low-temperature joining technology
referred to as pressure sintering, that is already known”
[specification, page 5]. Thus, conventional pressure sintering
is implied. To sinter something is defined as “to cause [it] to
become a coherent mass by heating without melting” [see for
example, Webster’s Ninth New Collegiate Dictionary, 1985]. When
the term “pressure sintered connection” is given this common and
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ordinary interpretation, it is clear that Potter fully meets the
literal recitations of claim 3.
There is no question that the components of Potter are
bonded to each other by way of a chromium-gold(silver)-
gold(silver)-chromium bond as discussed above. Potter describes
a process of applying pressure and heat to effect a thermal
compression bond. More specifically, Potter discloses that
“thermal compression bonding is taken to mean a process for
fabricating a robust permanent bond between two metal surfaces,
simultaneously using heat and pressure without melting either
metal surface” [column 3, lines 35-39, emphasis added]. The
application of pressure and heat to bond two metal surfaces
together without melting either metal surface as described by
Potter would appear to be the very definition of a “pressure
sintered connection.” Therefore, in our view, Potter clearly
discloses such a connection.
With respect to appellants’ argument that their pressure
sintered connection is different from Potter’s connection, we
agree with the examiner that there is no evidence in support of
this contention. We note that claim 3 recites no ranges of
pressure or temperature by which any unusual properties can be
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defined. At the scope defined by the recitation of claim 3, any
pressure sintered connection of Potter would meet the language of
the claim. We also agree with the examiner that even if
appellants had set forth specific values of pressure and
temperature in the claim, the burden would still be on appellants
to demonstrate that such values of pressure and temperature do,
in fact, result in a connection which is structurally different
from the connection of Potter. The claim is directed to an
article of manufacture, and the method by which the article is
made cannot, per se, be used to assert novelty of the article.
Thus, the invention of claim 3 is fully met by the
disclosure of Potter. Since Potter anticipates the invention of
claim 3, it must necessarily also render the invention of claim 3
obvious. Therefore, we sustain the rejection of claim 3 under 35
U.S.C. § 102(b) or under § 103.
We now consider the rejection of claim 8 under 35 U.S.C.
§ 102(b) as being anticipated by the disclosure of Potter. The
examiner notes that the diamond layer of Potter is mounted
directly on the copper heat sink through a possible intervening
layer as in appellants’ first and second embodiments, or that the
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layers 3, 2, 16, 17 and 1 of Potter are considered to be a
structural equivalent to the claimed means for eliminating heat
[answer, page 4]. Appellants argue that Potter does not
anticipate the claimed invention because there are four layers
between the Potter heat sink and the Potter diamond [brief, page
6]. The examiner responds that when the means for eliminating
heat is considered to include all of elements 3, 2, 16, 17 and 1
of Potter, then the carbon layer 4 of Potter is directly
connected to layer 3 which meets the claim recitation [answer,
pages 8-9].
We observe first that the examiner’s initial theory of
anticipation cannot be sustained. The direct mounting of claim 8
does not permit an intervening layer as suggested by the
examiner. The first and second embodiments of appellants’
invention (figures 2 and 3) show intervening layers, but are not
described
as being directly mounted. Appellants do not suggest that
mounting is direct until Figure 4 is described. Appellants note
that “[t]he embodiment shown in Figure 4 differs from the
embodiment shown in Figure 3 only in that the insulator layer
ISO4 is grown directly on the cooling member W4 and no connecting
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layer is provided between the insulating layer ISO4 and the heat
elimination means W4" [specification, page 7]. Appellants
proceed to describe the advantages of a direct connection and the
elimination of the connecting layers. Therefore, we interpret
the phrase “mounted directly” to require a connection such as
shown in appellants’ Figure 4 and which permits no intervening
layers.
The examiner’s second theory of anticipation requires
that layers 3, 2, 16, 17 and 1 of Potter all be considered as
part of the heat elimination means so that this combination is
directly connected to the carbon layer. The examiner indicates
that the five layers of Potter are structurally equivalent to the
heat sink W4 of the invention within the meaning of the last
paragraph of 35 U.S.C. § 112. We do not agree.
As we noted above, appellants disclose that the very
difference between a direct connection as shown in their Figure 4
and the connections of Figures 2 and 3 is that there are no
intervening layers in the direct connection of Figure 4.
Appellants disclose how this direct connection provides better
heat transmission resistance characteristics than any of the
embodiments which use intervening layers. In order to find
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structural equivalence, the examiner has ignored the specific
disclosure of being “mounted directly,” and has done precisely
the opposite thing from that disclosed. That is, we do not see
how the presence of layers 3, 2, 16 and 17 can be said to be
structurally equivalent to a connection which forbids the
presence of these intervening layers. In other words, the
presence of certain structure is not structurally equivalent to
the required absence of that structure.
Since we find the examiner’s interpretation of claim 8
under 35 U.S.C. § 112 to be unsupported by the record in this
case, we conclude that claim 8 is not anticipated by the
disclosure of Potter in the manner indicated by the examiner.
Therefore, we do not sustain the rejection of claim 8.
Claims 16 and 17 depend from claim 8 and recite that the
insulating and conducting layer of claim 8 is polycrystalline
carbon and monocrystalline carbon, respectively. The examiner
has rejected these claims under 35 U.S.C. § 103 as unpatentable
over the teachings of Potter for reasons discussed above. Even
though these claims depend from claim 8 and the rejection of
claim 8 as anticipated by Potter has not been sustained, we must
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still consider whether the invention of claims 16 and 17 would
have been obvious within the meaning of 35 U.S.C. § 103.
The examiner’s prima facie case of obviousness depends
upon his interpretation that layers 3, 2, 16, 17 and 1 of Potter
can be considered equivalent to the heat eliminator W4 of
appellants’ invention. As we noted above, we cannot agree with
this interpretation of claim 8. Absent this structural
equivalence as asserted by the examiner, there is no evidence on
the record in this case as to why it would have been obvious to
eliminate the intervening layers of Potter and to mount the
carbon component directly onto the heat sink 1. Thus, there is a
difference between claim 8 and the teachings of Potter which has
not been addressed by the examiner. The failure to address this
difference between claim 8 and Potter results in a failure to
establish a prima facie case of obviousness. Therefore, we do
not sustain the rejection of claims 16 and 17 under 35 U.S.C. §
103.
In summary, we have sustained the rejection of claims 1,
3, 9 and 10, but we have not sustained the rejection of claims 8,
16 and 17. Accordingly, the decision of the examiner rejecting
claims 1, 3, 8-10, 16 and 17 is affirmed-in-part.
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No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
§ 1.136(a).
AFFIRMED-IN-PART
)
JERRY SMITH )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
JAMESON LEE )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
JAMES T. CARMICHAEL )
Administrative Patent Judge )
Appeal No. 95-0543
Application 08/008,734
17
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