Prosecution Insights
Last updated: April 19, 2026
Application No. 18/859,168

SPHERICAL SILVER POWDER, METHOD OF PRODUCING SPHERICAL SILVER POWDER, SPHERICAL SILVER POWDER PRODUCTION APPARATUS, AND CONDUCTIVE PASTE

Final Rejection §103
Filed
Oct 23, 2024
Examiner
NGUYEN, TRI V
Art Unit
1764
Tech Center
1700 — Chemical & Materials Engineering
Assignee
DOWA ELECTRONICS MATERIALS CO., LTD.
OA Round
2 (Final)
67%
Grant Probability
Favorable
3-4
OA Rounds
3y 1m
To Grant
99%
With Interview

Examiner Intelligence

Grants 67% — above average
67%
Career Allow Rate
633 granted / 941 resolved
+2.3% vs TC avg
Strong +58% interview lift
Without
With
+57.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
47 currently pending
Career history
988
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
49.2%
+9.2% vs TC avg
§102
21.2%
-18.8% vs TC avg
§112
18.2%
-21.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 941 resolved cases

Office Action

§103
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 . Response to Amendment Upon entry of the amendment filed on 05 January 2026, Claim(s) 1, 7 and 11 is/are amended; Claim(s) 7-11 is/are withdrawn; and Claim(s) 6 is/are cancelled. The currently pending claims are Claims 1-5 and 7-13. Based on applicants’ remarks and amendments (e.g. the specific C/O relative ratio), the 102 rejections based on Yoon, the 103 rejections based solely on Osako and the 103 rejections based on Yoon/Osako and Dowa 873 are withdrawn. However, they are not found persuasive regarding the combination of Yoon/Osako and Dowa 863 and the rejections are updated and maintained. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claim(s) 1-4 and 12-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoon in view of Dowa 763 (JP2017-206763A, cited in the IDS). Claims 1-4: Yoon discloses spherical silver powders having a D50 range of 0.5-2.5 microns, a BET range of 0.1-2 m2/g and a true density of 9.8-10.2 – thus teaching at the claimed D50 / DBET ratio as calculated from applicant’s specification (abs, ¶16, 31, 41-46 and Tables 1 and 2 with accompanying text). The Yoon reference discloses the claimed invention but does not explicitly disclose the feature of the ratio of oxygen to carbon is 1.5 or more. In an analogous art, the Dowa 763 reference discloses that spherical silver powder having a ratio of oxygen to carbon is 1.5 or more is well known in the art (abs, ¶31-37 and examples). In particular, Dowa 763 discloses the benefit of enhanced thermal workability/sinterability (abs, ¶31-37 and examples). One of ordinary skill in the art would have recognized that applying the known technique and component of Dowa 763 to the teachings of Yoon would have yielded predictable results because the level of ordinary skill in the art demonstrated by the cited references shows the ability to apply such features into similar systems, methods and compositions. See MPEP 2143. Further, it is noted that obviousness only requires a reasonable expectation of success and there is no evidence nor teaching that the substitution would be repugnant to a skilled artisan. Claims 12 and 13: Yoon and Dowa 763 disclose the conductive paste with the binder and the organic solvent and the solar cell implementation (Yoon: ¶169-172, Tables 1 and 2 with accompanying text). Claim(s) 1, 3-4 and 12-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Osako in view of Dowa 763 (JP2017-206763A, cited in the IDS). Claims 1, 3-4: Osako discloses a spherical silver powder having a D50 range of 0.5-4 microns, a DBET range of 0.-3 microns and a BET range of 0.1-1.5 m2/g (abs, ¶16 and Tables 1 and 2 with accompanying text). The Osako reference(s) disclose(s) the claimed invention but do(es) not explicitly disclose the claimed D50 / DBET ratio range. Given that the Osako reference discloses a similar silver spherical powder, it would have been obvious to one of ordinary skill in the art at the time of the invention to choose the instantly claimed ranges through process optimization, since Osako discloses overlapping ranges and arriving at the claimed range only involves routine skills in the art. See MPEP 2144.05. Thus, it would have been obvious to one of ordinary skill in the art at the time of the invention to optimize known variables, i.e. the D50 / DBET ratio, since the reference also discloses a similar end-product. Further, obviousness only requires a reasonable expectation of success and there is no evidence nor teaching that the selection or optimization of the claimed variables would be repugnant to a skilled artisan. The Osako reference discloses the claimed invention but does not explicitly disclose the feature of the ratio of oxygen to carbon is 1.5 or more. In an analogous art, the Dowa 763 reference discloses that spherical silver powder having a ratio of oxygen to carbon is 1.5 or more is well known in the art (abs, ¶31-37 and examples). In particular, Dowa 763 discloses the benefit of enhanced thermal workability/sinterability (abs, ¶31-37 and examples). One of ordinary skill in the art would have recognized that applying the known technique and component of Dowa 763 to the teachings of Osako would have yielded predictable results because the level of ordinary skill in the art demonstrated by the cited references shows the ability to apply such features into similar systems, methods and compositions. See MPEP 2143. Further, it is noted that obviousness only requires a reasonable expectation of success and there is no evidence nor teaching that the substitution would be repugnant to a skilled artisan. Claims 12 and 13: Osako and Dowa 763 disclose the conductive paste with the binder and the organic solvent and the solar cell implementation (Osako: ¶1-3, 10, 11, 99 and Tables 1 and 2 with accompanying text). Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoon/Osako and Dowa 763 as applied to claim 1 above, and further in view of Dowa 873 (JP2012-214873A, cited in the IDS). The Yoon/Osako and Dowa 763 references disclose the claimed invention but do not explicitly disclose the feature of the ignition loss of less than 0.1 mass %. In an analogous art, the Dowa 873 reference discloses that spherical silver powder having an ignition loss of less than 0.1 mass % is well known in the art (¶11, 23-27 and claims 1-6 and examples). In particular, Dowa 873 discloses the benefit of enhanced electrical resistance and short circuit prevention (abs, ¶23-27 and examples). One of ordinary skill in the art would have recognized that applying the known technique and component of Dowa 873 to the teachings of Yoon/Osako and Dowa 763 would have yielded predictable results because the level of ordinary skill in the art demonstrated by the cited references shows the ability to apply such features into similar systems, methods and compositions. See MPEP 2143. Further, it is noted that obviousness only requires a reasonable expectation of success and there is no evidence nor teaching that the substitution and application would be repugnant to a skilled artisan. Response to Arguments Applicant’s arguments, see pg. 5-8, filed 05 January 2026, with respect to the 102 rejections based on Yoon, the 103 rejections based on Osako and the combination of Yoon/Osako and Dowa 873 have been fully considered and are persuasive. The respective rejections have been withdrawn. Applicant's arguments filed 05 January 2026 regarding the combination of Yoon/Osako and Dowa 763 have been fully considered but they are not persuasive. Applicant argues that Dowa 763 does not suggest the specific ratio of oxygen to carbon being 1.5 or more and the unexpected results of an improvement in the heating treatment (pg. 8 and 9). The examiner respectfully disagrees. At the onset, it is noted that a ratio of 1.5 or more is merely met by the carbon being absent and the amount of oxygen. Further, it is noted that Dowa 763 discloses measuring the amount of oxygen (see oxygen content section starting on ¶32), carbon (“measured amount of carbon” in ¶34) and optimizing the experimental conditions – thus, it would have been well within the purview of a skilled artisan to arrive at the claimed ratio via routine experimentation and there is no evidence nor teaching that the substitution and application would be repugnant to a skilled artisan. Regarding the unexpected results, applicant has merely provided a statement without any conclusive and/or substantive showing to indicate the criticality of the claimed values. Applicant is welcome to provide any declaration and/or showing indicating the criticality of the claimed C/O ratio being greater than 1.5. Conclusion THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to TRI V NGUYEN whose telephone number is (571)272-6965. The examiner can normally be reached M-F 9-5. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Arrie Lanee Reuthers can be reached at 571.272.7026. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /TRI V NGUYEN/Primary Examiner, Art Unit 1764
Read full office action

Prosecution Timeline

Oct 23, 2024
Application Filed
Oct 16, 2025
Non-Final Rejection — §103
Jan 05, 2026
Response Filed
Mar 13, 2026
Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
67%
Grant Probability
99%
With Interview (+57.9%)
3y 1m
Median Time to Grant
Moderate
PTA Risk
Based on 941 resolved cases by this examiner. Grant probability derived from career allow rate.

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