DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Group I, Claims 1-10 in the reply filed on 1/23/26 is acknowledged.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-10 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
With respect to claim 1, limitations “heating the whole” (line 6) and “the AuNbTi system” (line 10) lack sufficient antecedent basis since “whole” and “AuNbTi system” have not been previously defined. For purpose of examination and in accordance with broadest reasonable interpretation, the claim is taken to mean: heating to a temperature higher than the melting temperature of the braze… and intermetallic of AuNbTi compound.
As to claim 9, limitation “step d)” is ambiguous because no such step is defined in claim 1. Moreover, feature “secondary vacuum” is confusing since vacuum has not been previously mentioned. The recited vague language fails to clearly set forth the scope, rendering the claim indefinite. The vacuum appears to refer to the brazing/heating step in claim 1. For purpose of examination and in accordance with broadest reasonable interpretation consistent with the specification, the claim is taken to mean: heating is carried out under vacuum or under reducing atmosphere or under neutral gas.
Appropriate corrections are requested.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-2 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Koop et al. (US 4225262, hereafter “Koop”).
Regarding claim 1, Koop discloses a method for assembling a ceramic part (made of alumina, zirconia) to a titanium element with braze material (figure; col. 2, lines 10-21), the method comprising the following steps: coating a surface of the titanium element with a niobium layer (claim 7), positioning a braze between the zirconia part 12 and the titanium element 16 (figure), the braze being of gold (claim 8), heating to a temperature higher than the melting temperature of the braze, whereby an assembly comprising the zirconia part and the titanium element assembled by a brazing joint, which intrinsically comprises a first portion of gold or a gold alloy, a second portion formed by a reaction layer and a third portion formed by an oxide reaction layer (claim 12).
Although Koop is silent with respect to the brazing joint portion comprising a reaction layer of intermetallic of AuNbTi compound, all three elements Au, Nb & Ti are present at the joining interface. Notably, Koop teaches brazing temperature of about 1000-1100 °C (col. 2, line 56-58; claim 9), which is substantially similar to brazing temperature in applicant’s invention. In fact, example 1 of applicant’s specification discloses brazing temperature of 1080 °C [0131], which falls within temperature range taught by Koop. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), MPEP 2144.05. Accordingly, the brazing temperature in Koop necessarily results in a brazing joint comprising recited portions including a reaction layer of intermetallic AuNbTi compound as well as an oxide reaction layer. Concerning cooling, it would have been obvious to one of ordinary skill in the art to let the assembly cool down after brazing as part of conventional finishing operation in the method of Koop. Examiner notes any cooling meets the claim since particular cooling conditions are not recited.
As to claim 2, Koop discloses that the braze is made of gold (claim 8).
As to claim 9, Koop discloses that heating/brazing is carried out under vacuum (claim 10).
Claims 3 and 5-8 are rejected under 35 U.S.C. 103 as being unpatentable over Koop as applied to claim 1 above, and in view of Mizuhara (US 4486386).
As to claims 3 and 5, Koop does not disclose the braze being alloy comprising gold and titanium, or gold and zirconium. However, such braze alloy is known in the art. Mizuhara (drawn to reactive brazing alloys) discloses that when brazing a ceramic material to a metal member, the reliability of joint is good when the brazing alloy is reactive & ductile, as ductility compensates for the thermal expansion mismatch between the ceramic and metal members (col. 1, lines 27-31). Consequently, Mizuhara teaches reactive, ductile gold-based alloys, comprising gold, palladium and titanium, vanadium, zirconium & mixtures thereof; the amount of reactive metals (titanium, vanadium, zirconium) ranges from about 0.5-2% by weight (col. 1, lines 51-59; claim 1). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to utilize gold alloy(s) similar to Mizuhara in the brazing method of Koop because doing so would compensate for the thermal expansion mismatch between the ceramic and metal members and improve braze joint reliability.
As to claims 6-7, Mizuhara teaches that the amount of reactive metals (titanium, vanadium, zirconium) ranges from about 0.5-2% by weight in the gold-based alloys (col. 1, lines 51-59; col. 2- exemplary tables; claim 1), which overlaps with the claimed range of 0.5-4% by weight of titanium or zirconium. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.
As to claim 8, Mizuhara teaches 2 mil foil of gold-based alloy (Example 1- col. 2, line 35), which is equivalent to about 50 µm thickness, falling within claimed range of 25-200 µm. Thus, it would have been obvious to one of ordinary skill in the art to employ a braze foil having a suitable micron thickness in the brazing method of Koop & Mizuhara.
Claims 4 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Koop as applied to claim 3 above, and in view of Mizuhara (US 4486386) & Pimenta et al. (“Brazing of Zirconia to Titanium using Ag-Cu and Au-Ni filler alloys, 2013, pg. 349-357, see NPL of record).
As to claim 4, Koop as modified by Mizuhara above discloses the gold alloy including titanium, but lacks nickel. However, such constituent is known in the brazing art. Analogous to Koop, Pimenta (NPL) discloses brazing of zirconia to titanium using Ag-Cu or Au-Ni filler alloys (see title and abstract). Specifically, Pimenta teaches that Au-Ni filler provides excellent thermal conductivity and resistance to oxidation, with high ductility, which is also beneficial to accommodate thermal stresses via interfacial plastic flow (pg. 350- right column- Experimental procedures). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to incorporate nickel into the gold-alloy braze in Koop & Mizuhara because doing so would provide excellent thermal conductivity, resistance to oxidation and high ductility, leading to beneficial accommodation of thermal stresses, as suggested by Pimenta. Thus, combination of Koop, Mizuhara & Pimenta discloses gold braze alloy comprising gold, titanium and nickel.
As to claim 10, Pimenta teaches that before positioning the braze, the method comprises a step of cleaning the titanium & zirconia specimens by ultrasonic cleaning in bath for removing residues (pg. 350- right column- Experimental procedures). Consequently, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to clean the titanium & zirconia parts in the method of Koop & Mizuhara with a motivation to remove residues, thereby preparing the surfaces for reliable braze joint.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 12/21/22 complies with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Inquiry
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DEVANG R PATEL whose telephone number is (571) 270-3636. The examiner can normally be reached on Monday-Friday 8am-5pm, EST.
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/DEVANG R PATEL/
Primary Examiner, AU 1735
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