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 of Group 1 in the reply filed on 4/15/2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
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 1-8 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.
Regarding claim 1, the use of parentheses around “Si3N4” in the first line of claim 1 renders the claim indefinite because it is unclear if a product with the chemical formula is required. Claims 2-8 are rendered indefinite due to their dependence on claim 1.
Regarding claim 8, the claim requires heating to “a predetermined temperature”. However, claim 1, on which claim 8 depends, already recites “a predetermined temperature”. It is unclear if the predetermined temperature in claim 8 is the same predetermined temperature as claim 1 or if claim 8 is introducing a new predetermined temperature.
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.
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.
Claim(s) 1 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over KR20110050845A (KR’845).
Regarding claim 1, KR’845 teaches a method of producing silicon nitride (Si3N4) comprising preparing a mixed raw material powder comprising metallic silicon and sintering aids including yttria (Y2O3) and alkaline earth metal compounds such as MgO. See page 8 of the provided KR’845 machine translation. KR’845 teaches using CaO in the examples therein, KR’845 can be used as the alkaline earth component of the sintering aid. See page 8. The selection of a known material based on its suitability for its intended use supports a prima facie obviousness determination. See MPEP 2144.07.
KR’845 teaches granulating the mixture with an organic binder (PVA) using a spray dried to produce a specific granule size. See pages 8-9 of the KR’845 machine translation.
KR’845 teaches nitriding (exposing to nitrogen atmosphere) at 1300°C. See page 11 of the KR’845 machine translation.
KR’845 teaches granule separation by grinding (considered pulverizing). See top of page 12 of the machine translation.
Regarding claim 6, KR’845 teaches granules with sizes of 30-150 µm. See page 6 of the machine translation. Overlapping ranges are prima facie obviousness. See MPEP 2144.05.
Claim(s) 2-4 is/are rejected under 35 U.S.C. 103 as being unpatentable over KR20110050845A (KR’845) in view of JP2004-002122 (JP’122) (references are to the provided machine translation).
Regarding claims 2-3, KR’845 does not teach the raw metallic silicon powder is obtained from dry grinding a polycrystalline or single-crystal metallic silicon scrap. KR’845 is also silent regarding the resistivity of the silicon used therein. However, it was known in the art to utilize crystalline silicon scrap having a resistivity in the claimed range in the production of silicon nitride.
JP’122 teaches producing silicon nitride powder using at least single crystal silicon scrap with a resistivity of greater than 0.4 Ωcm, including 1 Ωcm. See [0005] and [0036]. JP’122 also teaches preparing the silicon scrap utilizing dry grinding methods such as methods using a jaw crusher and a vibration mill. See [0009] of JP’122.
One of ordinary skill in the art would have been motivated to use the dry ground single crystal silicon scrap material of JP’122 in as the silicon raw material in KR’845 with the motivation of reducing costs and utilizing waste material. See [0004] of JP’122.
Regarding claim 4, JP’122 teaches impurities are less than 10 µg/g, i.e. 99.999% purity [(1 –( 10 µg/1000000 µg)) *100%] or higher. See [0008].
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over KR20110050845A (KR’845) in view of KR20170135105 (KR’105) (references are to the provided machine translation).
Regarding claim 5, KR’845 is silent regarding the claimed particle sizes. However, it is known in the art to use silicon and sintering agents with particle sizes in the ranges claimed. KR’105 teaches in a method of producing silicon nitride, particle size of metallic silicon of 0.5-20 µm and particle size of the sintering aid (MgO and/or Y--2O3) of 0.5-20 µm. See [0057]-[0059] of KR’105.
In the process of KR’845, it would have been obvious to look to CN’105 for successful starting materials used in producing silicon nitride from silicon and sintering agents. The substitution of one known particle precursor for another would have been obvious to one of ordinary skill in the art with predictable result of producing silicon nitride upon nitridation.
Claim(s) 7 is rejected under 35 U.S.C. 103 as being unpatentable over KR20110050845A (KR’845) in view of Kusano et al., US2016/0362592.
Regarding claim 7, the claim requires 2-5 mol % yttrium oxide and 2-10 mol. % magnesium oxide. Kusano teaches in a method of producing silicon nitride using sintering agents comprising the amount of sintering agent of 2-6 wt.%.
However, it would have been obvious to one of ordinary skill in the art to modify KR’845 with KR’105, which teaches using 2-4 mol. % rare earth compound (Y2O3) and 8-15 mol. % magnesium compound (MgO). See [0060]-[0066] of Kusano. It would have been obvious to one of ordinary skill in the art to use the amounts disclosed in Kusano in order to obtain a silicon nitride product with desirable thermal conductivity as disclosed by Kusano.
Claim(s) 8 is rejected under 35 U.S.C. 103 as being unpatentable over KR20110050845A (KR’845) in view of Edler, US6007789.
Regarding claim 8, KR’845 is silent regarding the heating rate claimed and the nitrogen gas pressure. However, these parameters are known in the prior art.
Edler teaches a process of producing silicon nitride from silicon and sintering aid. Edler teaches temperature increasing rates from 1000°C of 5-50°C/hr until a predetermined temperature is reached. See column 4, lines 6-9 of Edler. Edler also teaches pure nitrogen atmospheres with pressures of 0.5-2 atm. (0.05 – 0.2 MPa). See column 4, lines 16-38 of Edler. Edler teaches these parameters are important for enhancing the nitridation of silicon so a more complete chemical conversion to silicon nitride can be achieved. See column 3, lines 1-4.
It would have been obvious to one of ordinary skill in the art to adjust the nitridation parameters of KR’845 in view of Edler in order to ensure a more complete chemical conversion of the silicon into silicon nitride.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Mikijelj, US8673795, teaches a method of producing silicon nitride by granulating silicon powder with yttria and magnesia and nitriding at 1400-1450°C. See the examples.
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ANTHONY J. ZIMMER
Supervisory Patent Examiner
Art Unit 1736
/ANTHONY J ZIMMER/Supervisory Patent Examiner, Art Unit 1736
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