Ex Parte Veeramma

Patent Trial and Appeal Board

Dec 15, 2017

13892237 (P.T.A.B. Dec. 15, 2017)

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.
IXYS-01328 7775
EXAMINER
YECHURI, S IT ARAM AR AO S
ART UNIT PAPER NUMBER
2818
MAIL DATE DELIVERY MODE
13/892,237 05/10/2013 Subhas Chandra Bose Jayappa Veeramma
47713 7590 12/15/2017
IMPERIUM PATENT WORKS
P.O. BOX 607
Pleasanton, CA 94566
12/15/2017 PAPER
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.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte SUBHAS CHANDRA BOSE JAYAPPA VEERAMMA1
Appeal 2017-001762
Application 13/892, Til2
Technology Center 2800
Before JEFFREY T. SMITH, MARKNAGUMO, and
MERRELL C. CASHION, JR., Administrative Patent Judges.
SMITH, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
This is an appeal under 35 U.S.C. § 134 from the final rejection of
claims 1 and 3—19.3 We have jurisdiction under 35 U.S.C. § 6.
We reverse.
Appellant’s invention relates generally to a packaged overvoltage
protection circuit comprising a Break Over Diode device (BOD). The BOD
1 This is the named inventor of the present application.
2 According to Appellant, the real party in interest is IXYS Corporation. See
App. Br. 1.
3 The Examiner has indicated the subject matter of claims 20—23 is
allowable. (Final Act. 2).
Appeal 2017-001762
Application 13/892,237
device undergoes breakover and turns on if an excessive forward voltage
develops across a power thyristor, coupled in parallel with the BOD. (Spec.
110). Independent claims 1, 9, and 12 are representative of the appealed
subject matter. Representative claims 1 and 12 are reproduced below:
1. A packaged overvoltage protection circuit comprising:
a first semiconductor die, wherein the first semiconductor die
comprises a breakover diode having a reverse breakdown
voltage of at least four hundred volts;
a second semiconductor die, wherein the second semiconductor
die comprises a breakover diode having a reverse breakdown
voltage of at least four hundred volts;
a package housing that encloses the first and second
semiconductor dice;
a first package terminal; and
a second package terminal, wherein the first and second
semiconductor dice are coupled such that if a positive voltage
of adequate magnitude is present between the second package
terminal and the first package terminal then breakover of the
breakover diodes in the first and second semiconductor dice
occurs and a current flows in a current path from the second
package terminal, through the breakover diode of the first
semiconductor die, through the breakover diode of the second
semiconductor die, and to the first package terminal, and such
that if a negative voltage of nine hundred volts or less is present
between the second package terminal and the first package
terminal then neither of the breakover diodes of the first and
second semiconductor dice suffers reverse breakdown, and
wherein the packaged overvoltage protection circuit has no
package terminal other than the first and second package
terminals.
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Application 13/892,237
12. An apparatus comprising:
a first package terminal;
a second package terminal, wherein the apparatus has no more
than two package terminals; and
means for blocking substantially all current flow from the
second package terminal to the first package terminal for
positive voltages less than a first voltage between the second
and first package terminals, for initiating conduction of a
breakover current from the second package terminal to the first
package terminal if a positive voltage equal to the first voltage
becomes present between the second and first package
terminals, and for blocking substantially all current flow from
the first package terminal to the second package terminal for
negative voltages less than a second voltage between the second
package terminal and the first package terminal, wherein the
absolute magnitude of the second voltage exceeds the first
voltage, wherein the first voltage is at least nine hundred volts,
wherein the means comprises no semiconductor die other than a
plurality of semiconductor dice, and wherein each die of the
plurality of semiconductor dice comprises a breakover diode.
Claims Appendix to App. Br.
Appellant (see generally App. Br.) requests review of the following
rejections:
I. Claims 1, 3—5, and 8 rejected under 35 U.S.C. § 103(a) as
unpatentable over Vogel (US 5,710,463 A, iss. Jan. 20,
1998) in view of Shombert (US 3,231,796 A, iss. Jan. 25,
1966). (Final Act. 3 — 5).
II. Claim 6 and 7 rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Vogel, Shombert, and
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Application 13/892,237
Thiele (US 4,651,251, iss. Mar. 17, 1987). (Final Act. 5 -
6).
III. Claims 9—11 rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Vogel, Shombert, and
Thiele. (Final Act. 6 — 9).
IV. Claims 12 and 13 rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Vogel and Shombert.
(Final Act. 9—11).
V. Claims 14—18 rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Vogel, Shombert, and
Thiele.4 (Final Act. 11-12).
VI. Claim 19 rejected under 35 U.S.C. § 103(a) as unpatentable
over the combination of Vogel, Shombert, and Thiele as
combined and further in view of Faust et al. (US 4,367,418
A, iss. Jan. 4, 1983). (Final Act. 12—13).
The complete statement of the rejections on appeal appears in
the Final Office Action. (Final Act. 3—13).
OPINION5
After consideration of the evidence in this appeal record in light of the
respective positions advanced by the Examiner and Appellant, we determine
the Examiner erred in the determination that the combination of Vogel and
4 The Examiner has included a discussion of claims 16—18 in the body of the
rejection. However, the Examiner has inadvertently excluded claims 16—18
from the statement of the rejection.
5 Our discussion applies to independent claims 1, 9, and 12.
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Application 13/892,237
Shombert teaches (i) a packaged overvoltage protection circuit with
breakover diodes having a reverse breakdown voltage of at least four
hundred volts as required by independent claims 1 and 9, and (ii) a two-
terminal apparatus with breakover diodes that block current flow between
the terminals for negative voltages greater than nine hundred volts in
magnitude as required by independent claim 12. Accordingly, we reverse
Rejections I—VI.6 7
Independent Claims 1, 9 and 12.1
Appellant argues neither Vogel nor Shombert teaches a breakover
diode having a reverse breakdown voltage that exceeds 400 V as required by
independent claim 1. (App. Br. 9-10). Appellant argues Vogel fails to
disclose a PNPN structure having a reverse breakdown voltage that exceeds
four hundred volts. Appellant argues the Examiner is relying on hindsight to
modify the breakover diode of Vogel in accordance with the teachings of
Shombert so that the breakover diode of Vogel would have a reverse
breakdown voltage. (App. Br. 10). Thus, Appellant argues the combination
of Vogel and Shombert would not have resulted in the claimed invention.
(App. Br. 13). Appellant further argues Shombert does not teach how to
modify a breakover diode to achieve a reverse breakdown voltage and the
Examiner fails to explain how the teachings of Shombert are utilized to
modify the breakover diode of Vogel. (App. Br. 13—14).
6 The additional references relied upon by the Examiner in the obviousness
rejections were cited to address limitations of the dependent claims that are
not related to our discussion of the independent claims.
7 Appellant relies on substantially the same arguments when addressing the
limitations of independent claims 1 and 9. (App. Br. 9-14, 16—18). We will
limit our discussion to claim 1.
5
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Application 13/892,237
Addressing independent claim 12, Appellant argues neither Vogel nor
Shombert teaches breakover diodes that block current flow for negative
voltages greater than nine hundred volts. (App. Br. 19). Appellant argues
Shombert fails to disclose a two terminal apparatus with breakover diodes
that block current flow for negative voltage between terminals. (App. Br.
19). Thus, Appellant argues the Examiner’s rejection is premised on
hindsight because no rationale has been provided to modify Vogel’s
breakover diodes to impart a reverse breakdown voltage. (App. Br. 20).
The Examiner found Vogel teaches a packaged overvoltage protection
circuit as required by the claimed invention. (Final Act. 3^4 (citing Fig. 3,
col. 3)). The Examiner found Vogel does not teach:
“having a reverse breakdown voltage of at least four hundred
volts” nor “such that if a negative voltage of nine hundred volts
or less is present between the second package terminal and the
first package terminal then neither of the breakover diodes of
the first and second semiconductor dice suffers reverse
breakdown.”
(Final Act. 4).
The Examiner found Shombert teaches how to adjust the forward
breakover and reverse breakdown voltages. The Examiner specifically
states:
Shombert [teaches] “Pnpn semiconductor switch with
predetermined forward breakover and reverse breakdown
voltages” where he teaches how to adjust the forward breakover
and reverse breakdown voltages. See column 2, 3 and 4[,] see
Fig. 1 . . . reverse breakdown.
(Final Act. 4).
The Examiner concluded it would be obvious to modify the Pnpn of
Vogel to meet the claimed invention. The Examiner specifically states:
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Application 13/892,237
it would be obvious to modify the Pnpn of Vogel to have
reverse breakdown voltage of for example 500 volts such that
“having a reverse breakdown voltage of at least four hundred
volts” and “such that if a negative voltage of nine hundred volts
or less is present between the second package terminal and the
first package terminal then neither of the breakover diodes of
the first and second semiconductor dice suffers reverse
breakdown.”
(Final Act. 5).
The Examiner cites Godse8 and McKay9 to explain electric
breakdown is inherent to semiconductor junctions and Vogel’s structure.
(Ans. 3—8). The Examiner points to Fig. 3 of McKay and states that the
breakdown voltage is “approaching 400 V and note that that is all that was
tested” (Ans. 5). The Examiner further states:
a person of ordinary skill in the art understands that the PNPN of
Vogel Fig. 3 relies upon reverse biased PN junctions to block
current from flowing in both directions, but the phenomenon of
Avalanche breakdown will also occur in both directions, thus the
Examiner states for the record that inherently the PNPN of Vogel
Fig. 3 has a reverse breakdown voltage and when that voltage is
exceeded current will flow in the direction from Cathode K to Anode
A and this is due to Avalanche breakdown of the reverse biased
junctions.
(Ans. 7—8).
In response to the Examiner’s newly presented inherency argument,
Appellant argues McKay clearly fails to show a reverse breakdown voltage
of at least 400V and FIG. 3 of McKay shows the breakdown voltage is well
8 Atul P. Godse & Deepali A. Godse, Electronics and Microprocessors, 58—
64 (2008).
9 K. G. McKay, Avalanche Breakdown in Silicon, 94/4 Physical Review
877-84 (1954).
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Application 13/892,237
below 400V. (Reply Br. 5). Appellant further argues nowhere does the
cited art teach the claimed breakover diode having a reverse breakdown
voltage of at least 400V. (Reply Br. 5).
We agree with Appellant that the Examiner’s rejections of the
independent claims 1, 9, and 12 are not well-founded. An inherent
characteristic must be inevitable, and not merely a possibility or probability.
See In re Oelrich, 666 F.2d 578, 581 (CCPA 1981). The Examiner has not
pointed to a specific embodiment in Vogel that teaches the disputed subject
matter. Nor has the Examiner provided an explanation as to how the
teachings of Shombert would have been combined with the teachings of
Vogel to necessarily result in (i) a packaged overvoltage protection circuit
with breakover diodes having a reverse breakdown voltage of at least four
hundred volts as required by independent claims 1 and 9, and (ii) a two-
terminal apparatus with breakover diodes that block current flow between
the terminals for negative voltages greater than nine hundred volts in
magnitude as required by independent claim 12. The Examiner’s reliance on
Godse and McKay does not establish that the structure of Vogel alone or in
combination with the teachings of Shombert inherently encompasses a
reverse breakdown voltage of at least four hundred volts or a two-terminal
apparatus with breakover diodes that block current flow between the
terminals for negative voltages greater than nine hundred volts in magnitude
as required by the claimed invention.
Accordingly, we reverse the Examiner’s decision to reject claims 1
and 3—19 for the reasons presented by Appellant and given above.
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ORDER
The obviousness rejections of claims 1 and 3—19 are reversed.
REVERSED
9