Ex Parte Wochner et al

Patent Trial and Appeal Board

Apr 28, 2017

13229098 (P.T.A.B. Apr. 28, 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.
13/229,098 09/09/2011 Hanns WOCHNER W1154/20027 8871
3000 7590
CAESAR RIVISE, PC
7 Penn Center, 12th Floor
1635 Market Street
Philadelphia, PA 19103-2212
05/02/2017 EXAMINER
BRATLAND JR, KENNETH A
ART UNIT PAPER NUMBER
1714
NOTIFICATION DATE DELIVERY MODE
05/02/2017 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):
patents @ crbcp .com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte HANNS WOCHNER and WALTER HAECKL1
Appeal 2015-007933
Application 13/229,098
Technology Center 1700
Before TERRY J. OWENS, CATHERINE Q. TIMM, and
JEFFREY R. SNAY, Administrative Patent Judges.
TIMM, Administrative Patent Judge.
DECISION ON APPEAL2
STATEMENT OF CASE
Pursuant to 35 U.S.C. § 134(a), Appellants appeal from the
Examiner’s decision to reject claims 1, 3—6, 10-13, and 15—19. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM-IN-PART.
1 The real party in interest is Wacker Chemie AG. Appeal Br. 2.
2 In explaining our Decision, we cite to the Specification dated September 9,
2011 (Spec.), Final Office Action dated January 26, 2015 (Final), the Appeal
Brief dated May 19, 2015 (Appeal Br.), and the Examiner’s Answer dated
August 6, 2015 (Ans.).
Appeal 2015-007933
Application 13/229,098
The claims are directed to a method for producing thin silicon rods.
See, e.g., claims 1 and 10. These thin silicon rods are used in a process of
forming polycrystalline silicon, from which are cut silicon wafers for use in
fabricating electronic components (semiconductor chips). Spec. 1:10—18.
To begin the process of producing the thin silicon rods, Appellants cut
a rod of polycrystalline silicon (polysilicon) into thin rods by, for instance,
mechanical sawing. Spec. 6:15—23. Because cutting results in surface
contamination, the surface of the thin rod is cleaned by conventional means
such as chemical etching. Spec. 2:23—3:2; 6:24—7:2.
To increase yield in the process of depositing silicon onto the thin rod,
it is desirable to be able to use longer thin rods. Spec. 3:32—33. In principle,
longer thin rods can be produced by welding together shorter thin rods.
Spec. 4:1—2. Appellants disclose an induction welding process for welding
several shorter thin rods to form a longer thin rod. Spec. 7:4—10; 8:7—10:5.
Ultimately, Appellants package the welded thin rods in tubular bags.
Spec. 10:7—8. During the welding process, the silicon surface is easily
contaminated with metal impurities that must be removed by another
cleaning step before packaging. Spec. 10:15—11:18. However, cleaning the
long thin rods poses a problem: the size of the conventional plastic etching
tanks is limited and steel strut reinforcements are prone to corrosion by the
acid etchant. Spec. 5:15—27.
Appellants’ invention is directed to the welding method and to the
step of cleaning the welded thin rods using an etching tank and trough
arrangement that can accommodate the long thin rods through openings in
the end faces of the tank. The etchant is allowed to flow out through the
openings along the rod and is collected in the trough below.
2
Appeal 2015-007933
Application 13/229,098
Claim 1 illustrates the inventive method and contains limitations
directed to the etching tank and trough used in the second cleaning step. We
reproduce claim 1 from the Claims Appendix of the Appeal Brief with
limitations particularly relevant to the issue on appeal highlighted:
1 A method for producing thin silicon rods,
comprising:
a) providing a rod of polycrystalline silicon, from
which are separated at least two thin rods with a reduced cross
section in comparison with the polycrystalline silicon rod;
b) cleaning the at least two separated thin rods by
treatment with a material-eroding liquid medium to provide
cleaned thin rods;
c) welding at least two of the cleaned thin rods to
form a longer thin rod;
d) cleaning the longer thin rod by treatment with an
additional material eroding liquid medium as a second cleaning
step, the second cleaning step of the longer thin rod including
reducing the concentration of metals on the polycrystalline
silicon longer thin rod via chemical etching in a tank containing
the additional material-eroding liquid medium, which on both
end faces has an opening, respectively, through which the
longer thin rod is passed gradually in order to reduce the
concentration of metals thereon, the additional material­
eroding liquid medium which flows out along the longer thin
rod through the openings being collected in a trough arranged
below the tank and pumped back into the tank,
e) drying the longer thin rod; and
f) in an automated continuous process including step
d) through step f), packaging the longer thin rod in a tubular
film,
wherein, after passing the longer thin rod through the
tank and drying the longer thin rod, the longer thin rod is
immediately introduced into the tubular film and packaged.
Appeal Br. 12 (emphasis added).
3
Appeal 2015-007933
Application 13/229,098
Claim 10, the other independent claim, does not include the
limitations highlighted above, but is further limited with regard to the
welding apparatus.
The Examiner maintains the following rejections under 35 U.S.C.
§ 103(a):
A. Claims 1,3,4, 11, and 19 as obvious over Oyoshi3 in view of AAPA,4
Wochner I,5 and Angelini;6
B. Claims 5, 6, 12, 13, 15, and 16 as obvious over Oyoshi in view of
AAPA, Wochner I, and Angelini and further in view of Wochner II7;
C. Claim 17 as obvious over Oyoshi in view of AAPA, Wochner I,
Angelini, Wochner II, and further in view of Merkel8;
D. Claim 18 as obvious over Oyoshi in view of AAPA, Wochner I, and
Angelini, and further in view of Schellenberger9; and
E. Claim 10 as obvious Oyoshi in view of AAPA, Wochner I, and
Merkel
3 Oyoshi et al., JP 63-242339, published Oct. 7, 1988 (as translated in the
English Abstract (Patent Abstracts of Japan) and by McElroy Translation
Co. in Feb. 2014).
4 Applicants’ Admitted Prior Art, Spec. 2:14-3:30.
5 Wochner et al., US 2010/0154357 Al, published June 24, 2010.
6 Angelini, US 3,751,344, issued Aug. 7, 1973.
7 Wochner et al., US 6,309,467 Bl, issued Oct. 30, 2001.
8 Merkel et al, US 3,200,001, issued Aug. 10, 1965.
9 Schellenberger et al., US 5,714,203, issued Feb. 3, 1998.
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Appeal 2015-007933
Application 13/229,098
OPINION
Rejections A—D
For the rejections of claims 1, 3—6, 11—13, and 15—19 (Rejections A—
D), the issue is: Have Appellants identified a reversible error in the
Examiner’s findings regarding the combination of the teachings of Angelini
with those of Oyoshi and AAPA to support the obviousness of chemical
etching a welded thin silicon rod in a tank and trough arrangement as
required by claim 1 ?
Appellants have identified such an error. Specifically, we agree with
Appellants that the combination is based on improper hindsight
reconstruction.
The Examiner acknowledges that Oyoshi does not teach cleaning by
passing the welded rod through openings in a tank with the etchant flowing
out of the openings and collecting in a trough as required by claim 1, step
(d). Angelini is concerned with surface roughening a bar, wire, or tube
before continuously chrome plating the bar, wire, or tube. Angelini,
Abstract; col. 4,11. 27—30. The suggestion of using the tank and trough
arrangement of Angelini for etching long welded silicon rods comes from
Appellants’ own disclosure, not from knowledge within the prior art.
The Examiner’s reliance on additional prior art does not cure the
deficiency. Thus, we do not sustain the rejection of claim 1 or the rejection
of the claims depending from claim 1.
Rejection E
The Examiner rejects claim 10 under 35 U.S.C. § 103(a) as obvious
over Oyoshi in view of AAPA, Wochner I, and Merkel.
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Appeal 2015-007933
Application 13/229,098
Claim 10 reads:
10. A method for producing thin silicon rods,
comprising:
a) providing a rod of polycrystalline silicon, from
which are separated at least two thin rods with a reduced cross
section in comparison with the polycrystalline silicon rod;
b) cleaning the at least two separated thin rods by
treatment with a material-eroding liquid medium to provide
cleaned thin rods;
c) welding at least two of the cleaned thin rods within
a quartz tube to form a longer thin rod, the welding including
creating a convective flow of an inert gas through the quartz
tube from a lower opening in the quartz tube to an upper
opening thereof, and heating one end of the thin rods within the
quartz tube with an induction coil arranged within the quartz
tube and over a carbon tube encapsulated in the quartz tube to
above a melting temperature of silicon and forming a drop of
liquid silicon therefrom, the convective flow of inert gas
shielding the heated silicon from ambient air, wherein
subsequently the induction coil is switched off and the rods fuse
to form the longer thin rod; and
d) packaging the longer thin rod in a tubular film.
Appeal Br. 13—14.
There is no dispute that Oyoshi teaches welding two thin rods (5, 5’)
within a tube 4 to form a longer thin rod. Compare Final 16, with Appeal
Br. 8—9; Oyoshi p. 6. Nor is there any dispute that Oyoshi creates a
convective flow of an inert gas (argon inlet 10 to exhaust 11) and heats the
ends of the thin rods (5, 5’) with an induction coil 13 arranged within tube 4.
Compare Final 14, 16, and Ans. 6, with Appeal Br. 8—9; see also Oyoshi pp.
6—7; Fig. 1. Or that tube 4 is lowered over heating ring 12 provided on the
top end of guide tube 6. Compare Final 14, 16, and Ans. 6, with Appeal Br.
8—9; see also Oyoshi pp. 6—7; Fig. 1.
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Appeal 2015-007933
Application 13/229,098
The Examiner acknowledges that Oyoshi does not disclose forming
tube 4 of quartz and forming ring 12 of carbon, but turns to Merkel to
support the conclusion that it would have been obvious to form Oyoshi’s
tube 4 of quartz and form Oyoshi ring 12 of graphite “to facilitate rapid
heating.” Final 17.
Appellants do not dispute the Examiner’s finding of a suggestion to
use a quartz tube and a ring of graphite to facilitate rapid heating in the
welding apparatus of Oyoshi. Instead, Appellants contend that the
Examiner’s rejection fails to be supported because Merkel’s high frequency
coil 21 is situated outside quartz tube 11 (Merkel Fig. 1), whereas
Appellants’ claim 10 requires the coil be inside the quartz tube. Appeal Br.
8. But Appellants’ contention does not properly consider the findings and
conclusion of the Examiner. The Examiner finds that Oyoshi teaches coil 13
inside a tube 4. The Examiner is not relying upon Merkel’s arrangement of
the coil and tube, but on Oyoshi’s coil and tube arrangement. Final 17—18;
Ans. 5—6. Appellants’ have not identified a reversible error in the
Examiner’s reliance on Oyoshi for the coil and tube arrangement.
Because Appellants have not identified a reversible error in the
rejection of claim 10, we sustain that rejection.
CONCLUSION
We sustain the Examiner’s rejection of claim 10, but do not sustain
the Examiner’s rejection of claims 1, 3—6, 11—13, and 15—19.
DECISION
The Examiner’s decision is affirmed-in-part.
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Appeal 2015-007933
Application 13/229,098
TIME PERIOD FOR RESPONSE
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).
AFFIRMED-IN-PART
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