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 .
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.
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.
Claim(s) 1 and 3-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nakamura (JP 2004-323293), an English computer translation (CT) is provided, in view An (KR10- 2011-0062415), a computer translation (CT2) is provided.
Nakamura teaches a method for producing a SiC single crystal substrate comprising: placing a SiC single crystal serving as a seed crystal S and a SiC powder layer M in a container (die D) (dense body) in a state in which the SiC single crystal and the SiC powder layer are in contact with each other, an upper punch (dense body) and lower punch (dense body); and performing a heat treatment by placing the container to grow a SiC single crystal on the seed crystal (Fig 1-2; CT [0011]-[0015] teaches bringing the raw material powder into contact with a seed crystal, pressurizing it under heating, and a transfer of mass from the raw material powder to the seed crystal occurs, causing a single crystal to grow on the seed crystal). Nakamura teaches an example comprising pressure molding performed as a hot press with a surface pressure of 40 MPa under heating at 2050°C for 2 hours, and the resulting sintered body was subjected to heat treatment at 1900°C for 24 hours to grow a single crystal (Fig 1-2; CT [0027]-[0043]), which clearly suggests a temperature range within ±50°C of a preset temperature. Nakamura teaches an embodiment where a 3C-SiC thin film 12 formed on the front surface of a Si substrate 10 is used as the seed crystal and only one side of the seed 12 is in contact with the powder 16 (Nakamura CT [0019]-[0023]; Fig 2), which clearly suggests only one side of the seed crystal is in contact with the SiC powder layer.
Nakamura teaches using a die and pressure molding at 2050°C. However, Nakamura does not explicitly teach a furnace.
In a conventional pressure sintering furnace, An teaches a die (14) and a punch (15) made of high-density, high-strength graphite material positioned in the center of the sintering furnace (10) so as to apply high pressure to the product. And, the heating unit (12) is connected to an external power source and raises the temperature by resistance heating inside the sealed sintering furnace (10), and using high-density graphite having 80~99% of the theoretical density. (Fig 1, 4, and 6; CT2 page 2-3), which clearly suggests a firing furnace.
It would have been obvious to one of ordinary skill in the art at the time of filing to modify Nakamura by using a firing furnace, as taught by An, to heat the die and SiC powder to a desired temperature.
Referring to claim 3, the combination of Nakamura and An teaches a hot press with a surface pressure of 40 MPa under heating at 2050°C for 2 hours (Nakamura CT [0030]-[0050]), which clearly suggests maintaining this temperature which would be within +20 of the preset temperature.
Referring to claim 4, the combination of Nakamura and An teaches a hot press with a surface pressure of 40 MPa under heating at 2050°C for 2 hours (Nakamura CT [0030]-[0050]), which clearly suggests maintaining this temperature which would be within +10 of the preset temperature.
Referring to claim 5-9, the combination of Nakamura and An teaches the punch (dense body) and die (dense body) contact the outer circumferential edge of the SiC powder layer (Nakamura Fig 1) and the punch and die with 80~99% of the theoretical density, which clearly suggests a relative density of greater than 96% (An CT2 page 2-3). Overlapping ranges are prima facie obvious (MPEP 2144.05).
Response to Arguments
Applicant's arguments filed 06/24/2026 have been fully considered but they are not persuasive.
Applicant’s argument that the prior art does not teach wherein only one side of the seed crystal is in contact with the SiC powder layer is noted but not found persuasive. Applicant alleges that it is necessary that a step of melting the SiC sintered body 14 through the melted Si substrate 10; therefore, does not teach only one side of the seed crystal being in contact with the SiC powder layer. First, Applicant’s argument is not persuasive because Figure 2 clearly shows only one side of the seed crystal layer 12 is in contact with the SiC powder layer 16 because the backside of the seed layer 12 is covered by the Si substrate 10. Second, Applicant’s argument is not persuasive because Nakamura teaches a compacted SiC powder containing C powder is placed on the back of the Si substrate, during the heat treatment process, the Si that melts during the heating process reacts with the excess C to form SiC microcrystals (CT [0024]); therefore, powder SiC is not in contact with the backside of the seed crystal 12 because a molten layer of Si is present and reacted to form an intervening layer. Finally, applicant’s argument is not persuasive because claim 1 recites placing the SiC seed in contact with the SiC powder layer wherein only one side of the seed is in contact with the SiC powder layer, then performing a heat treatment. As discussed above, Nakamura clearly teaches only one side of the SiC layer 12 is in contact with the powder layer 16 prior to heat treatment; therefore, meets the claim.
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Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Takebe et al (US 2021/0025031) teaches Graphite (having a purity of 99.9% or more, and a relative density of sintered compact (density of sintered compact/ideal density) of 99% or more) is set to be used as the standard sample ([0076]).
Wu et al (CN 1291419), an English computer translation (CT3) is provided, teaches an apparatus used in the SiC/Cu composite material preparation method consists of a punch 1, a mold body 4, a press table 5, and an electric furnace 6 (Fig 1; CT3 [0013]), and SiC particles are filled into a cavity of a mold and pressed into a preform; preheating the mold containing SiC particles, pressure is applied by a press, the pressure is 40MPa-60MPa, the pressure is maintained and the mixture is cooled; demolding and taking out an ingot (CT3 [0006]).
Hiruta et al (JP 10-101434A), a computer translation (CT4) is provided, teaches the relative density of a pressure medium is preferably 96% or more, and if its relative density of the pressure medium is low, a graphite cylinders will bend and crack. (CT4 [0048]).
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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MATTHEW J. SONG
Examiner
Art Unit 1714
/MATTHEW J SONG/Primary Examiner, Art Unit 1714
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