DETAILED ACTION
This is an Office action based on application number 18/015,864 filed 12 January 2023, which is a national stage entry of PCT/JP2021/026273 filed 13 July 2021, which claims priority to JP2020-122560 filed 17 July 2020. Claims 1-5, 7, 9-15, and 17-22 are pending.
Amendments to the claims, filed 10 March 2026, have been entered into the above-identified application.
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 .
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-5, 7, 9-15, and 17-21 are rejected under 35 U.S.C. 103 as being unpatentable over Nakazumi et al. (WIPO International Publication No. WO 2019/208129 A1, citations taken from English language equivalent US Patent Application US 2021/0238381 A1) (Nakazumi) in view of Becker et al. (EP 1 637 571 A2, citations taken from the provided machine translation) (Becker).
Regarding instant claims 1-2, 4, and 21-22:
Nakazumi discloses a thermosetting composition comprising boron nitride and a thermosetting compound, wherein the thermosetting compound contains a maleimide compound and a polyphenylene ether (Claim 1).
Said maleimide compound is construed to have a maleimide group in a molecule. Further, absent further limitations required by the limitation of “a curing agent reactable with the ether compound”, said maleimide is construed to meet said limitation because it is the same composition required by the limitations of Applicant’s Claim 4.
Nakazumi teaches that the content of boron nitride contributes to thermal conductivity (paragraph [0103]).
Nakazumi further discloses that the content of boron nitride is 0.1 to 25 parts by mass based on 100 parts by mass of the compound (paragraph [0103]), which overlaps the claimed range. However, “in the case where claimed ranges ‘overlap or lie inside ranges disclosed by prior art’ a prima facie case of obviousness exists.” See MPEP § 2144.05.
Nakazumi further discloses that the average particle size of the boron nitride is between 0.1 to 20 μm to optimize, at least, the thermal conductivity and dielectric constants (paragraph [0107]).
Nakazumi further discloses that the composition further comprises an inorganic filler (E) other than boron nitride, wherein said inorganic filler (E) is inclusive of silica (Claim 2).
Nakazumi further discloses that the inorganic filler (E) has an average particle size of 0.1 to 10 μm to improve both dielectric constants and thermal conductivity (paragraph [0110]).
Nakazumi does not explicitly disclose the particle size distribution of the boron nitride and silica.
However, Becker discloses an adhesive composition having improved thermal conductivity and the use of such compositions to produce composite components having improved thermal conductivity (paragraph [0001]).
Becker further discloses that the adhesive compositions comprise thermally conductive filers (paragraph [0014]).
Becker further disclose that the fillers are inclusive of boron nitride and quartz having an average particle size of less than 50 μm; furthermore, Beker teaches that the use of a trimodal particle size distribution brings about the most dense possible packing of the filler in the binder matrix (paragraph [0020]). One of ordinary skill in the art would readily recognize that quartz is a type of silica.
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art, having the teachings of the prior art before him or her, to use filler particles having a trimodal particle size distribution, as prescribed by Becker, in the composition of Nakazumi. The motivation for doing so would have been that both Nakazumi and Becker use boron nitride and silica particles as thermally conductive fillers, and Becker teaches that a trimodal distribution ensures the densest possible packing of said particles, wherein one of ordinary skill in the art would conclude that a dense packing contributes to thermal conductivity.
Given the particle size range disclosed by both Nakazumi and Becker, as well as the positive the disclosure of a trimodal particle size distribution, the prior art combination is construed to encompass, within its scope, the particle size distributions recited by the claims; however, “in the case where claimed ranges ‘overlap or lie inside ranges disclosed by prior art’ a prima facie case of obviousness exists.” See MPEP § 2144.05.
Alternatively, since the instant specification is silent to unexpected results, the specific particle size distribution of the boron nitride and silica fillers are not considered to confer patentability to the claims. As the packing density is a variable that can be modified, among others, by adjusting the trimodal particle size distribution of the particles, the precise distributions would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed amount cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the trimodal particle size distribution of the filler particles in the prior art combination to obtain the desired packing density (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
The prior art combination does not explicitly disclose that the particle size distribution is measured by a laser diffraction-based particle size distribution measuring method. Absent evidence of criticality regarding how the particle size distribution is measured and given that the particle size distribution is obviated by the prior art combination, it is the Examiner's position that the prior art combination meets the requirements of the instant claims.
The disclosure of a bimodal distribution of boron nitride particles (i.e., two groups of boron nitride particles having a different average particle size) is construed to meet the recited “two types of boron nitride filler”.
The prior art combination does not explicitly disclose that the particle size distribution is measured by a laser diffraction-based particle size distribution measuring method. Absent evidence of criticality regarding how the particle size distribution is measured and given that the particle size distribution is obviated by the prior art combination, it is the Examiner's position that the prior art combination meets the requirements of the instant claims.
Therefore, it would have been obvious to combine Becker with Nakazumi to obtain the invention as specified by the instant claims.
Regarding instant claim 3:
Nakazumi further discloses that the polyphenylene ether contains a compound represented by formula (4):
PNG
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111
611
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Greyscale
wherein formula (4) meets the claimed [Chemical formula 1], reproduced below, when R1, R2, and R3 are hydrogen, z is a phenylene group, and s is 1:
PNG
media_image2.png
121
352
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Greyscale
Regarding instant claim 5:
Nakazumi further discloses that the composition further comprises an inorganic filler (E) other than boron nitride, wherein said inorganic filler (E) is inclusive of aluminum oxide (Claim 2) (i.e., alumina).
Regarding instant claims 7 and 9-10:
Nakazumi further discloses that the content of boron nitride is 0.1 to 25 parts by mass based on 100 parts by mass of the compound (paragraph [0103]).
Nakazumi further discloses that the content of the inorganic filler (E) inclusive of silica is 1 to 1600 parts by mass based on 100 parts by mass of the thermosetting compound (paragraph [0111]).
The total of the boron nitride and the inorganic filler (E) is construed to meet the claimed total content of the inorganic filler. Further, given then ranges disclosed, Nakazumi is construed to overlap or include the individually claimed boron nitride content, the silica content, and the relative volume of boron nitride to total volume of inorganic filler. However, ; however, “in the case where claimed ranges ‘overlap or lie inside ranges disclosed by prior art’ a prima facie case of obviousness exists.” See MPEP § 2144.05.
Regarding instant claim 11:
Nakazumi further discloses that the thermosetting compound contains other thermosetting compounds having at least one or more functional groups capable of undergoing a polymerization reaction or a cross-linking reaction inclusive of polymerizable unsaturated groups (paragraph [0094]).
Nakazumi further discloses that the compounds having polymerizable unsaturated groups are inclusive of styrene (paragraph [0101]).
Regarding instant claim 12:
Nakazumi teaches that the optimization of the particle sizes of the fillers selected from boron nitride and silica improves thermal conductivity and decreases dielectric constants (paragraphs [0107; 0110]).
Since the instant specification is silent to unexpected results, the specific thermal conductivity and relative dielectric loss constant are not considered to confer patentability to the claims. As the such properties are variables that can be modified, among others, by adjusting the filler particle sizes, the precise amounts would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed amount cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, at least the filler particle sizes in the prior art combination to obtain the desired thermal conductivity and dielectric constant (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
Regarding instant claim 13:
Nakazumi further discloses a prepreg obtained by impregnating a base material with the thermosetting composition, and then semi-curing the thermosetting composition (paragraph [0123]).
Nakazumi further discloses that said base material includes fibers (paragraph [0124]).
Regarding instant claim 14:
Nakazumi further discloses a resin composite sheet produced by coating a support with a solution of the thermosetting resin composition and then drying (paragraph [0128]).
Regarding instant claims 15 and 20:
Nakazumi further discloses a resin composite sheet produced by coating a support with a solution of the thermosetting resin composition and then drying (paragraph [0128]).
Nakazumi further discloses that examples of the support are inclusive of copper foil and aluminum foil (paragraph [0129]).
Regarding instant claim 17:
Nakazumi further discloses a wiring board comprising an insulating layer comprising the thermosetting composition and an etched conductor layer formed on the surface of the insulating layer (paragraph [0126]). Said etched conductor layer reads on the claimed “wiring”.
Nakazumi further discloses that layers of the thermosetting composition are subsequently cured (paragraph [0131]).
Regarding instant claims 18-19:
Nakazumi further discloses metal foil-clad laminates comprising at least one of the prepregs having metal foil disposed on one or both surfaces of the prepreg. Nakazumi further discloses that an inner layer circuit board is also disposed on the prepreg (paragraph [0125]). Said circuit board reads on the claimed “wiring”.
While Nakazumi does not explicitly disclose that the prepreg is an “insulating layer”, said prepreg is construed capable of acting as the claimed “insulating layer” because it is the same structure and composition.
Answers to Applicant’s Arguments
Applicant’s arguments regarding the prior art rejections of record are fully considered, but are unpersuasive.
Applicant alleges that the claimed recitations are neither fully taught or reasonably suggested by the cited prior art, alone or in combination.
Applicant cites that Nakazumi discloses the content of boron nitride is 0.1 to 25 parts by mass based on 100 parts by mass based on the thermosetting compound, whereas the claimed invention includes a content of boron nitride being 15 to 30 parts by weight relative to 100 parts by volume, which Applicant alleges is an indication that the content of boron nitride of their invention is higher than that of Nakazumi.
Applicant’s argument is unpersuasive. As cited above, the range disclosed by Nakazumi overlaps the claimed range. “[I]n the case where claimed ranges ‘overlap or lie inside ranges disclosed by prior art’ a prima facie case of obviousness exists.” See MPEP § 2144.05. Applicant has not presented evidence and persuasive arguments to overcome the prima facie case of obviousness.
Applicant further argues that Nakazumi relates to a thermosetting resin exhibiting, at least thermal conductivity. On the other hand, Applicant argues that Becker relates to a hot-melt adhesive, wherein boron nitride is listed as one of many possible inorganic fillers suitable for increasing thermal conductivity.
Applicant’s argument is unpersuasive. Although Nakazumi and Becker are drawn to different types of resin compositions, both suggest the use of boron nitride to achieve thermal conductivity. Applicant merely pointing out that Nakazumi and Becker are drawn to different compositions does not persuasively traverse why one of ordinary skill in the art would not combine the cited teachings of the references.
Further, Applicant argues that Becker merely states that it may be advantageous to use bimodal or trimodal particle size distribution to achieve the densest possible packing of the filler in the binder matrix. Applicant argues that such a general disclosure of the prior art combination does not render obvious the specific and deliberate selection of boron nitride fillers having controlled particle size peaks within the ranges, nor does it suggest that this would lead to the simultaneous improvement of dielectric properties, thermal conductivity, and peel strength. Applicant further argues that their examples demonstrate that the claimed effect is not achieved when boron nitride is replaced with other fillers.
Applicant’s argument is unpersuasive. The fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
In the instant case, one of ordinary skill in the art would readily modify the boron nitride and silica fillers of Nakazumi by using the trimodal distribution of Becker to obtain an optimal packing density of the sake of thermal conductivity. Any other benefits related to the modification (e.g., the increased peel strength touted by Applicant) would flow naturally from following the suggestion of the prior art, absent evidence to the contrary. Applicant has not shown by way of persuasive evidence that the particle size distribution encompassed by the prior art combination would not achieve the same results. Further, if Applicant believes that unexpected results are attributable to the claimed particle size distribution(s), then the claims must be commensurate in scope with the evidentiary support.
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.
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/TAM/Examiner, Art Unit 1788 03/24/2026
/Alicia Chevalier/Supervisory Patent Examiner, Art Unit 1788
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