JOHNSON MATTHEY PUBLIC LIMITED COMPANY

Patent Trials and Appeals Board

Mar 4, 2022

2021005356 (P.T.A.B. Mar. 4, 2022)

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. 15/568,854 10/24/2017 Jonathan Charles Shepley BOOTH 032891.000148 1050 148994 7590 03/04/2022 BakerHostetler / Johnson Matthey 1735 Market Street Suite 3300 Philadelphia, PA 19103-7501 EXAMINER SUN, MICHAEL Y ART UNIT PAPER NUMBER 1726 NOTIFICATION DATE DELIVERY MODE 03/04/2022 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): eofficemonitor@bakerlaw.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte JONATHAN CHARLES SHEPLEY BOOTH, TOBIAS DROSTE, BEATRIZ CELA GREVEN, and NICOLAS NOWAK1 ____________ Appeal 2021-005356 Application 15/568,854 Technology Center 1700 ____________ Before GEORGE C. BEST, CHRISTOPHER C. KENNEDY, and MERRELL C. CASHION, JR., Administrative Patent Judges. KENNEDY, Administrative Patent Judge. DECISION ON APPEAL This is an appeal under 35 U.S.C. § 134(a) from the Examiner’s decision rejecting claims 1, 7, 9, 11, 12, 15-19, and 26-29. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. The Appellant identifies the real party in interest as Johnson Matthey Public Limited Company. Appeal Br. 1. Appeal 2021-005356 Application 15/568,854 2 BACKGROUND The subject matter on appeal relates to conductive pastes for solar cells. E.g., Spec. 1:4-6; Claim 1. Claim 1 is reproduced below from page 11 (Claims Appendix) of the Appeal Brief: 1. A conductive paste for a solar cell, the paste comprising a solids portion dispersed in an organic medium, the solids portion comprising an electrically conductive metal and a mixed oxide, wherein the mixed oxide is a tellurium-bismuth-cerium mixed oxide that is substantially lead-free and substantially silicon-free and comprises: 35 to 65 wt% of TeO2; 25 to 50 wt% of Bi2O3; 0.1 to 5 wt% of Li2O; 0 to 5 wt% of Na2O; 0.1 to 5 wt% of ZnO; 0 to 3 wt% of MoO3; 0.5 to 15 wt% of CeO2; 0 to 3 wt% of WO3; 0 to 5 wt% of BaO; 0 to 10 wt% of P2O5; and 0 to 10 wt% of a further component that is of GeO2, CaO, ZrO2, CuO, AgO or Al2O3. ANALYSIS Claims 1, 7, 9, 11, 12, 15-19, and 26-29 stand rejected under 35 U.S.C. § 103 as unpatentable over Park (US 2016/0013331 A1, published Jan. 14, 2016) and Kim (US 2014/0042375 A1, published Feb. 13, 2014). After review of the cited evidence in the appeal record and the opposing positions of the Appellant and the Examiner, we determine that the Appeal 2021-005356 Application 15/568,854 3 Appellant has not identified reversible error in the Examiner’s rejection. Accordingly, we affirm the rejection for reasons set forth below, in the Final Action dated Nov. 13, 2020, and in the Examiner’s Answer. The Examiner finds that Park teaches a conductive paste for a solar cell that includes each element of claim 1 except that Park discloses a Bi2O3 concentration of 5-20 wt% which does not fall within the scope of the claimed range of 25-50 wt%. Ans. 4. The Examiner finds that Kim teaches a conductive paste for solar cells comprising 5-55 wt% Bi2O3. Id. The Examiner finds that Kim teaches that including at least 5 wt% Bi2O3 reduces or avoids deterioration of contact resistance, and that including a maximum of 55 wt% Bi2O3 results in reduced or avoided damage to a junction by the paste. Id. The Examiner finds that it would have been obvious “to increase the Bi2O3 wt% of Park et al. to the Bi2O3 wt% of Kim et al. in order to provide a glass frit with lower resistance and lower damage to a junction by the electrode paste.” Id. at 4-5. The sole issue on appeal is whether it would have been obvious to increase the Bi2O3 concentration of Park’s paste to a range that falls within the scope of claim 1, e.g., 25 wt%, in view of Kim. As an initial matter, we observe that Park, Kim, and the application on appeal each concern the same subject matter: conductive pastes suitable for use in solar cells. See, e.g., Park at Title; Kim at Title; Spec. (Title). Park, Kim, and the application on appeal each desire pastes with good adhesion, contact resistance, and efficiency. Compare Park at Abstr.; with Kim ¶¶ 24, 26; with Spec. 1:19-26, 2:6-8. The upper end of Park’s Bi2O3 range (20 wt%) falls squarely within Kim’s range (5-55 wt%) and differs from the lower end of the claimed range (25 wt%) by only 5 wt%. The range taught Appeal 2021-005356 Application 15/568,854 4 by Kim, 5-55 wt%, essentially spans the ranges of Park (5-20 wt%) and claim 1 (25-50 wt%). The prior art makes clear that the concentration of Bi2O3 in a conductive paste for solar cells is a result-effective variable that affects contact resistance and junction integrity. E.g., Kim ¶ 28. The Examiner’s proposal involves a modest increase (5 wt%) in the concentration of Park’s Bi2O3 (a known result-effective variable) to a level (25 wt%) that is a known suitable level for conductive pastes used in solar cells, such as Park’s. “Normally, it is to be expected that a change . . . in concentration . . . would be an unpatentable modification.” In re Aller, 220 F.2d 454, 456 (CCPA 1955); see also In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990) (“The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims . . . . [and] in such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range.” (citations omitted)). The Examiner’s combination could also be described as the use of a known element (Kim’s 25 wt% Bi2O3) according to its established function (ingredient in a conductive solar paste) with predictable results. The use of known elements according to their established functions typically does not result in nonobvious subject matter. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416-21 (2007) (“The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results.”); see also id. at 416 (“[W]hen a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.”). Appeal 2021-005356 Application 15/568,854 5 The Appellant first argues that the Examiner has not adequately established a reason to combine Park and Kim. Appeal Br. 4-6. In particular, the Appellant points out that Park’s range (5-20 wt%) is completely encompassed by Kim’s range (5-55 wt%) such that the contact resistance and junction integrity benefits discussed by Kim would already be present in Park without modification. Id. That argument is not persuasive for reasons discussed above. Namely, the Examiner is proposing the use of a known suitable concentration for use in the same application (conductive paste for solar cells). Such combinations typically do not result in nonobvious subject matter. See KSR, 550 U.S. at 416-21. Additionally, a person of ordinary skill in the art reasonably would have optimized Bi2O3 concentration from 20 wt% to 25 wt% according to desired contact resistance and joint damage resistance. See Aller, 220 F.2d at 456; see also Woodruff, 919 F.2d at 1578. The Appellant next argues that Kim’s teachings apply only to conductive pastes comprising lead, and, therefore, that Kim’s Bi2O3 concentrations above 20 wt% were not known or expected to be suitable in the substantially lead-free embodiment of Park relied upon by the Examiner. Appeal Br. 6-8. That argument is not persuasive for two reasons. First, Kim specifically contemplates “lead-free glass frit.” Kim ¶ 34. Although we acknowledge some ambiguity as to whether Kim’s paste compositions do or do not require the presence of PbO, we observe that Kim ¶ 27 states that the glass frit “may be” a three-component glass frit (PbO, Bi2O3, TeO2). Kim’s paragraphs 33 and 34 refer to “the” glass frit, and expressly refer to a “lead glass frit, lead-free glass frit, or a mixture thereof” (emphasis added). The Appeal 2021-005356 Application 15/568,854 6 Appellant argues that paragraph 34’s reference to a “lead-free glass frit” is an “addition[al]” glass frit that may be added to Kim’s glass frit that allegedly requires PbO. However, Kim describes its glass frit in the singular, and specifically states that the glass frit may be a “mixture” of lead and lead-free glass frit, or may be a “lead-free glass frit” alone. We agree with the Examiner that paragraph 34 suggests a lead-free glass frit, and the Appellant has not identified any disclosure in Kim that the disclosed Bi2O3 concentration range of 5-55 wt% would be incompatible with a lead-free grass frit. Other art of record, i.e., Park, discloses that at least Bi2O3 concentrations in the lower portions of Kim’s range would indeed be compatible with lead-free grass frit. E.g., Park ¶ 36 (discussing leaded and lead-free glass frits). Second, even were we to agree with the Appellant that Kim’s particular glass frit require the presence of some PbO, the Appellant does not adequately explain why an absence of PbO would somehow make, e.g., 25 wt% an unsuitable concentration of Bi2O3. Kim describes certain properties affected by the concentration of Bi2O3 without reference to PbO. E.g., Kim ¶ 28. Kim describes embodiments having, e.g., 5 wt% PbO, id. ¶ 27, and also suggests lead-free embodiments, id. ¶ 34. The Appellant provides no persuasive reason to believe that a person of ordinary skill in the art familiar with Kim would believe that Kim’s disclosures concerning Bi2O3 concentration would apply only to glass frits including lead. Relatedly, as noted above, Park ¶ 36 also contemplates both leaded and lead- free glass frits, and the Appellant identifies nothing in Park that suggests that the Bi2O3 concentration depends on the presence of lead. The Appellant asserts that a different reference-Takeda Appeal 2021-005356 Application 15/568,854 7 (US 2010/0126565 A1, published May 27, 2010)-“stands for the proposition that in glass frit systems containing Bi2O3 and PbO, there is an interdependency between these components that militates against the omission of one or the other, especially at higher levels of Bi2O3.” Appeal Br. 8. The Appellant, however, provides no explanation of this alleged interdependency and fails to identify whether the “higher levels of Bi2O3,” id., at which the interdependency is allegedly present, would include levels as low as 25 wt%. The entirety of the Appellant’s explanation consists of a parenthetical reference to a previous filing in the prosecution history of the application on appeal. Id. That parenthetical reference, however, is inadequate because incorporation by reference is not permitted in Appeal Briefs. See, e.g., MPEP § 1205.02 (“[T]he brief should not incorporate or reference previous responses.”). Accordingly, the Appellant’s references to Takeda fail to establish that a person of ordinary skill in the art familiar with Kim would have believed that Kim’s disclosures concerning Bi2O3 concentration would apply only to glass frits including lead, particularly in view of the fact that the Appellant has not identified anything in either Park or Kim that suggests such an interdependency. The Appellant’s final argument is that Park teaches away from increasing its Bi2O3 concentration beyond 20 wt%. Appeal Br. 9-10. In particular, the Appellant refers to Table 1 of Park, which includes a single example of a composition with more than 20 wt% Bi2O3. See Park ¶ 54 (Table 1). The Appellant argues that, because the single example with more than 20 wt% Bi2O3 had certain properties that were worse than examples with 20 wt% or less Bi2O3, a person of ordinary skill in the art would have Appeal 2021-005356 Application 15/568,854 8 understood that amounts of Bi2O3 in excess of 20 wt% are undesirable. Appeal Br. 9-10. That argument is unpersuasive for reasons set forth by the Examiner in the Answer. See Ans. 9. Namely, from the single example relied on by the Appellant (Comparative Example 3), “it is unclear if the changes in efficiency, Voc, Rs, and adhesive strength are affected specifically by Bi2O3 or at least one of TeO2, ZnO, Li2O, or WO3.” Id. In that regard, we note that Table 1 also provides comparable examples with 20 wt% Bi2O3 or less that also yield undesirable results. We are not persuaded that Table 1 teaches away from concentrations of Bi2O3 in excess of 20 wt%. Park indicates a preference for Bi2O3 concentrations within the specifically disclosed range of 5-20 wt%, but the Appellant has not persuasively shown that Park teaches away from concentrations higher than that. See In re Fulton, 391 F.3d 1195, 1201 (Fed. Cir. 2004) (“The prior art’s mere disclosure of more than one alternative does not constitute a teaching away from any of the[] [disclosed] alternatives . . . .”); see also DePuy Spine, Inc. v. Medtronic Sofamor Danek, Inc., 567 F.3d 1314, 1327 (Fed. Cir. 2009) (“A reference does not teach away . . . if it merely expresses a general preference for an alternative . . . .” (internal quotation marks omitted)). CONCLUSION Appeal 2021-005356 Application 15/568,854 9 In summary: Claims Rejected 35 U.S.C. § References Affirmed Reversed 1, 7, 9, 11, 12, 15-19, 26-29 103 Park, Kim 1, 7, 9, 11, 12, 15-19, 26-29 No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). AFFIRMED