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/Arguments
Applicant's arguments with respect to claims 1 – 5, and 7 – 11 have been considered. Claims 1 – 5 and 7 – 11 were incorrectly rejected under 35 U.S.C. 102(a)(1). Therefore, the Final Rejection dated June 12, 2026 is hereby withdrawn. Please find the new ground(s) of rejection below.
In the response to the Office Action dated June 12, 2026, Applicant argues that the newly cited secondary reference, Tsugawa, does not disclose “wherein an amount of warpage of the silicon nitride substrate in every 100 mm in a direction along each side of the silicon nitride substate is 0.03 mm or less,” as recited in independent claim 1. Applicant contends that Tsugawa does not disclose or suggest a structure in which a ceramic insulating substrate is combined with a brazing material layer and metal layers. Examiner respectfully disagrees. Figure 3 of Tsugawa discloses a silicon nitride-metal composite that includes at least a silicon nitride substrate 1, a metal plate 2, and a brazing material layer 3 present between the two layers (paragraph [0119]). In other words, the silicon nitride substrate 1 and the metal plate 2 are bonded by the brazing material layer 3. Applicant further states that warpage arises from the interaction among the ceramic substrate, brazing layers, and metal layers, and therefore the mechanism and technical considerations for suppressing warpage are fundamentally different from those of a single ceramic substrate. In this case, Tsugawa discloses more than a single ceramic substrate. Again, Tsugawa discloses a silicon nitride-metal composite that includes at least a silicon nitride substrate, a metal plate, and a brazing material layer.
Further, Applicant argues that Tsugawa discloses warpage of a bare, pre-bonding silicon nitride substrate, and not warpage of the claimed composite structure. Applicant is reminded that claim 1 merely recites that an amount of warpage of the silicon nitride substrate is 0.03 mm or less.
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.
Claims 1 – 5 and 7 - 11 are rejected under 35 U.S.C. 103 as being unpatentable over Abe et al. (JP 2011-67849A) in view of Tsugawa et al. (U.S. Patent Publication No. 2022/0177377).
Regarding claim 1, in Figures 1 – 4, Abe discloses a ceramic substrate, consisting essentially of: a rectangular flat plate-shaped silicon nitride substrate (21) (support substrate 21 can be made of silicon nitride, paragraph [0050]); a first brazing material layer (31, paragraph [0037]) provided on a first main surface (21a, top surface of substrate 21) of the silicon nitride substrate; a second brazing material layer (32, paragraph [0037]) provided on a second main surface (21b, bottom surface of substrate 21) of the silicon nitride substrate; a first metal layer (51, paragraph [0037]) for mounting an electric circuit component (41a, 41b; 41a and 41b are circuit members, paragraph [0029]) and comprising a metal (paragraph [0037]) and being fixed through the first brazing material layer to the silicon nitride substrate on a first main surface-side (Figure 1); and a second metal layer (52, paragraph [0037]) for dissipating heat generated by the electric circuit component and comprising a metal (paragraph [0037]) and being fixed through the second brazing material layer to the silicon nitride substate on a second main surface-side (Figure 1), wherein the first metal layer and the second metal layer are made of a same metal (paragraph [0037] and a difference in thickness between the first metal layer and the second metal layer is 0.02 mm or less (the metal layers 51 and 52 are set to the same thickness, paragraph [0082], thus, the difference in the thicknesses of the metal layers 51 and 52 is zero or about zero, which is less than 0.02 mm), wherein a thickness of the first brazing material layer and a thickness of the second brazing material layer are 11.2 µm or more and 20.4 µm or less at any location (joining layers 31, 32 are 0.02mm = 20 µm thick; paragraph [0082]), wherein a difference between the thickness of the first brazing material layer at a given point and the thickness of the second brazing material layer at a point located behind the given point is 4.0 µm or less (the bonding layers 31 and 32 are set to the same thickness, paragraph [0082], thus, the difference in the thicknesses of bonding layers 31 and 32 is zero or about zero, which is less than 4.0 µm), wherein an amount of warpage of the silicon nitride substrate in every 100 mm in a direction along each side of the silicon nitride substate is 0.03 mm or less. Abe does not specifically disclose wherein an amount of warpage of the silicon nitride substrate in every 100 mm in a direction along each side of the silicon nitride substate is 0.03 mm or less. However, in paragraph [0070], Tsugawa discloses controlling the amount of warpage per unit length of a silicon nitride substrate to be less than 1.0 µm/mm.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention for the amount of warpage of the silicon nitride substrate 21 of Abe to be 0.03 mm or less in every 100 mm in a direction along each side of the silicon nitride substate as taught by Tsugawa in order to have low warpage and/or to reduce the amount of warpage in the substrate.
Regarding claim 2, Abe discloses wherein a relational expression (Ta-Tb)/Ta≤0.2 is satisfied where Ta is the larger of the thickness of the first brazing material layer and the thickness of the second brazing material layer at a given point and Tb is the smaller of the two (paragraph [0082]).
Regarding claim 3, Abe discloses wherein one of the first metal layer and the second metal layer comprises a circuit plate on which an electrical circuit component is mounted, and the other comprises a heat dissipation plate, and wherein a difference between a thickness of the first metal layer and a thickness of the second metal layer is not more than 0.02 mm (Figures 1 – 4).
Regarding claim 4, Abe discloses wherein the insulating base has a rectangular shape, and wherein an amount of warpage of the insulation base in every 100 mm in a direction along each side of the insulation base is not more than 0.03 mm (paragraph [0050]).
Regarding claim 5, Abe discloses a ceramic divided substrate that is formed by dividing the ceramic substrate according to claim 1 into a plurality of pieces (Figures 1 – 4).
Regarding claim 7, Abe modified by Tsugawa discloses the ceramic substrate according to claim 1. Abe modified by Tsugawa does not specifically disclose wherein a difference control between the thickness of the first brazing material layer at the given point and the thickness of the second brazing material layer at the point located behind the given point is controlled within a precision of 4.0 µm or less. However, providing for the difference of the thicknesses of a first layer and a second layer to be controlled within a requisite precision is common place and well known in the art, and is merely a design option for a skilled artisan without the exercise of inventive skill.
Regarding claim 8, Abe discloses wherein a precision being significant figures for 4.0 µm, wherein the first brazing material layer and the second brazing material layer varying in thickness along a length at different points (Figures 1 – 4).
Regarding claim 9, Abe modified by Tsugawa discloses the ceramic substrate according to claim 1. Abe modified by Tsugawa does not specifically disclose wherein a difference control between the thickness of the first brazing material layer at a given point and the thickness of the second brazing material layer at the given point is controlled to a maximum difference of 4.0 µm with significant digits. However, providing for the difference of the thicknesses of a first layer and a second layer to be controlled within a requisite precision is common place and well known in the art, and is merely a design option for a skilled artisan without the exercise of inventive skill.
Regarding claim 10, Abe discloses wherein a thickness of the first brazing material layer varies within a range of 13.8 µm or more along a length of the first brazing material layer, while the thickness of the second brazing material layer varies within a range of 11.2 µm or more along a length of the second brazing material layer (Figures 1 – 4).
Regarding claim 11, Abe modified by Tsugawa discloses the ceramic substrate according to claim 10. Abe modified by Tsugawa does not specifically disclose wherein a difference control between the thickness of the first brazing material layer at the given point and the thickness of the second brazing material layer at the given point is configured to be controlled to within a maximum difference of 4.0 µm. However, providing for the difference of the thicknesses of a first layer and a second layer to be controlled within a requisite precision is common place and well known in the art, and is merely a design option for a skilled artisan without the exercise of inventive skill.
Allowable Subject Matter
Claim 6 is allowed.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TREMESHA W BURNS whose telephone number is (571)270-3391. The examiner can normally be reached Monday-Friday 8am - 4:30 pm EST.
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TREMESHA W. BURNS
Primary Examiner
Art Unit 2847
/TREMESHA W BURNS/Primary Examiner, Art Unit 2847
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