DETAILED ACTION
Response to Amendment
Amendment filed on 15 July 2026 has been entered. Claims 1-10 are now pending in the application.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-4 and 6-8 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claim(s) 1-2, 6 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Gottwald (US 20180226315) in view of Mills (US 20140185194).
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Annotated Fig. 9, Gottwald.
Regarding claim 1, Gottwald teaches, a system for a busbar, comprising:
a body of the busbar (bus bars 120.1, 120.2, annotated Fig. 9) including a coating (isolating layer 210) of a thermally conducting dielectric material (isolating layer or layer sequence 210 made of prepreg and/or prepreg plus internal-layer material…As an alternative to prepreg, glass-fiber-free dielectric materials with sufficient thermal conductivity can also be used, para. [0058]), the body in face sharing contact with a heat sink (heat sinks K1, K2, Fig. 9) via a thermal interface material (thermal interface material 214, Fig. 9, layers 214 made of a thermally conductive material (TIM: thermal interface material) para. [0063]), wherein the thermal interface material directly contacts both the coating of the body and the heat sink (see Fig. 9).
Gottwald does not tech, coating a powder material. However, Mills teaches, a busbar (electrical buss members 132,134,136,138,140,142, Fig. 10) including a coating of thermally conducting dielectric powder material (electrical buss members 132,134,136,138,140,142…and dielectric powder coating, para. [0041]).
Gottwald teaches in para [0058], alternative to the isolating layer coating 210, dielectric materials having sufficient thermal conductivity can be used. Mills teaches in para. [0041], a coating of thermally conducting dielectric powder material. Therefore, in view of the teachings of Mills, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify busbar of Gottwald and to replace the prepreg isolating layer 210 with a dielectric powder coating as Mills disclosed in para. [0041] so that it enables providing the busbars with a desired dielectric breakdown voltage as Mills disclosed in para. [0041].
Regarding claim 2, Gottwald in view of Mills teaches the recited limitations with respect to claim 1. Gottwald further teaches, the system of claim 1, wherein the busbar includes one or more uncoated external connection portions originating from the body (two first busbars 120.1, 120.2 and to the two second busbars 122.1, 122.2…thus ensure an electrical connection between the two switching elements, para. [0059]), and wherein the thermal interface material is the only material disposed between the coating of the body and the heat sink (see Fig. 9).
Regarding claim 6, Gottwald teaches, a system, comprising:
a metallic busbar (bus bars 120.1, 120.2, annotated Fig. 9) with a surface area at least partially laminated with an electrically insulating, thermally conductive material (isolating layer or layer sequence 210 made of prepreg and/or prepreg plus internal-layer material…As an alternative to prepreg, glass-fiber-free dielectric materials with sufficient thermal conductivity can also be used, para. [0058]); and
a thermal interface material (thermal interface material 214, Fig. 9, para. [0063]) compressed in an interface of the busbar and a heat sink (heat sinks K1, K2, Fig. 9), wherein the thermal interface material directly contacts both the electrically insulating, thermally conductive powder material of the body and the heat sink (see Fig. 9).
Gottwald does not tech, coating a powder material. However, Mills teaches, a busbar (electrical buss members 132,134,136,138,140,142, Fig. 10) including a coating of thermally conducting dielectric powder material (electrical buss members 132,134,136,138,140,142…and dielectric powder coating, para. [0041]). Gottwald teaches in para [0058], alternative to the isolating layer coating 210, dielectric materials having sufficient thermal conductivity can be used. Mills teaches a coating of thermally conducting dielectric powder material. Therefore, in view of the teachings of Mills, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify busbar of Gottwald and to replace the prepreg isolating layer 210 with a dielectric powder coating as Mills disclosed in para. [0041] so that it enables providing the busbars with a desired dielectric breakdown voltage as Mills disclosed in para. [0041].
Regarding claim 8, Gottwald in view of Mills teaches the recited limitations with respect to claim 6. Gottwald further teaches, the system of claim 6, wherein the powder material is a dielectric material including an epoxy resin (isolation layer coating 210 made of prepreg, para. [0058], prepreg comprises epoxy resin, see Sun et.al., Thermal analysis of curing process of epoxy prepreg. J. Appl. Polym. Sci., 83: 2002, 1074-1083).
Claim(s) 5 is rejected under 35 U.S.C. 103 as being unpatentable over Gottwald in view of Mills as applied to claim 1 above, and further in view of McPherson (US 20180206359).
Regarding claim 5, modified Gottwald does not teach, a thickness of the coating. However, McPherson teaches, a power module 100 comprising busbar system 900 in Fig. 21 including conformal dielectric coating 914, in which, a thickness of the coating on the body is in a range of 0.2 mm and 0.5 mm (thickness of one of the conductors 910, 912 along with the dielectric film 914 may be 0.5 mm to 10 mm, para. [0163]). Therefore, in view of the teachings of McPherson, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify the busbar as taught by Gottwald and replace the coating with the dielectric film 914 as taught by McPherson so that the coating enables minimizing the inductance between the conducting busbars.
Claim(s) 9 is rejected under 35 U.S.C. 103 as being unpatentable over Gottwald in view of Mills as applied to claim 1 above, and further in view of Esseghir (US 20140125439).
Regarding claim 9, modified Gottwald does not teach, a dielectric strength. However, Esseghir teaches, a thermally conducting and electrically insulating coating, in which, the system of claim 1, wherein the coating has a dielectric strength in a range of 3000 and 4000 V/mm (dielectric breakdown strength of generally from about 10 kV/mm to about 45 kV/mm, para. [0083]). One skilled in the art would have expected the claimed dielectric strength range of 3 to 4 kV/mm from the prior art dielectric strength ranges. Therefore, in view of the teachings of Esseghir, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify the busbar as taught by Gottwald and replace the coating with a coating having dielectric breakdown strength from 10 kV/mm to 45 kV/mm, as taught by Esseghir so that it enables the busbars to operate at a continuous operating temperature as Esseghir disclosed in para. [0007].
Allowable Subject Matter
Claims 3-4 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Claims 7 and 10 would be allowable.
The following is an examiner’s statement of reasons for indicating allowable subject matter:
Claim 3 would be allowable for disclosing a system for a busbar, further comprising a pressure plate in face sharing contact with a first side of the body of the busbar, the pressure plate compressing the body of the busbar to the thermal interface material, the thermal interface material directly contacting a second side of the body of the busbar, opposite the first side.
Claim 4 would be allowable for disclosing a system for a busbar, wherein each of the busbar and the heat sink are in contact with power devices, the body of the busbar dissipating heat to a cooling fluid flowing through the heat sink via the thermally conducting dielectric powder material and the thermal interface material.
Prior art of record Gottwald does not teach, a pressure plate in face sharing contact with a first side of the body of the busbar, the pressure plate compressing the body of the busbar to the thermal interface material, the thermal interface material directly contacting a second side of the body of the busbar, opposite the first side; or each of the busbar and the heat sink are in contact with power devices, the body of the busbar dissipating heat to a cooling fluid flowing through the heat sink via the thermally conducting dielectric powder material and the thermal interface material.
Prior arts McPherson and Esseghir fail to teach, a pressure plate in face sharing contact with a first side of the body of the busbar, the pressure plate compressing the body of the busbar to the thermal interface material, the thermal interface material directly contacting a second side of the body of the busbar, opposite the first side; or each of the busbar and the heat sink are in contact with power devices, the body of the busbar dissipating heat to a cooling fluid flowing through the heat sink via the thermally conducting dielectric powder material and the thermal interface material.
Therefore, claims 3-4, 7 and 10 would be allowable.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 JOSE K. ABRAHAM whose telephone number is (571)270-1087. The examiner can normally be reached Monday-Friday 8:30-4:30 EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, THOMAS J. HONG can be reached at (571) 272-0993. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JOSE K ABRAHAM/Examiner, Art Unit 3729
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