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, 3, 5, and 9-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tonomura (US 2013/010429), and further in view of Kato (JP 2011/230954).
Regarding claim 1, Tonomura teaches a ceramic substrate (210, Fig. 10, [0149]) comprising:
a ceramic base (211, Fig. 10, [0149]);
a first metal sheet (212, Fig. 10, [0149]) bonded to an upper portion (Fig. 10, [0149]) of the ceramic base and provided in a circuit pattern shape (212, [0149]); and
a second metal sheet (213 and 240 combined, Fig. 10, [0149], [0152]) bonded to a lower portion (Fig. 10, [0149]) of the ceramic base, wherein the second metal sheet includes:
a flat portion (213 and 241 combined, Fig. 10, [0149]) in contact with a lower surface of the ceramic base; and
a plurality of heat dissipation fins (246, Fig. 10, [0152]) formed to protrude from a lower portion of the flat portion at intervals (Fig. 10) and in contact with liquid refrigerant (Fig. 10, [0152], 242 having liquid refrigerant are shown in contact with 241),
wherein the flat portion has a multi-layer structure (241A and 241B, [0153]), the flat portion comprising:
an intermediate layer (213, [0154], [0155]);
an upper metal layer ([0155], bonding interface between 213 and 211) formed on an upper surface of the intermediate layer ([0155]); and
a lower metal layer (230, [0154]) formed on a lower surface of the intermediate layer,
the upper metal layer and the lower metal layer are made of the same metal material ([0154], [0155]),
the intermediate layer is made of a different metal material from the upper metal layer and the lower metal layer ([0151]), and
materials of the upper metal layer and the lower metal layer are Cu ([0154], [0155]).
Tonomura does not teach a material of the intermediate layer is any one of CuMo and Mo.
However, Kato teaches molybdenum layers (61 and 71, Fig. 8, [0036]) on both surfaces of a ceramic substrate (10, Fig. 8, [0036]), and one of the Mo layers (71) has heat radiation with copper fins ([0036]). Kato also teaches having a Mo layer on each surface of the ceramic substrate is effective in preventing the occurrence of warping, cracks, and the like of the ceramic substrate due to thermal stress generated in a high temperature heat cycle ([0039]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the intermediate layer (Tonomura: 213, “metal layer”) to use Mo because Mo is effective in preventing the occurrence of warping, cracks, and the like of the ceramic substrate due to thermal stress generated in a high temperature heat cycle (Kato: [0039]).
Regarding claim 3, Tonomura does not teach the plurality of heat dissipation fins have an aspect ratio of 1:3.
However, having an aspect ratio of 1:3 would have involved a mere change in the proportion of a device which is generally recognized as being within the level of ordinary skill in the art, and the device will still function property with the size modification.
Therefore, having an aspect ratio of 1:3 for the plurality of heat dissipation fins is a matter of choice which a person of ordinary skill in the art would have found obvious absent persuasive evidence that such a modification is significant. (See Gardner v. TEC Syst., Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984))
Regarding claim 5, Tonomura teaches a bonding layer disposed between a lower surface of the first metal sheet and an upper surface of the ceramic base and between the lower surface of the ceramic base and the flat portion of the second metal sheet ([0155]),
wherein the bonding layer is made of a material including Ag ([0155]).
Regarding claim 9, Tonomura teaches a method of manufacturing a ceramic substrate ([0158]), comprising:
preparing a ceramic base (211, [0161]);
preparing a first metal sheet having a circuit pattern shape (212, [0159]);
preparing a second metal sheet (213 and 240 combined, [0159], [0167]) provided with a plurality of heat dissipation fins (246, [0167]); and
bonding the first metal sheet to an upper portion of the ceramic base ([0161]) and bonding the second metal sheet to a lower portion of the ceramic base ([0162]),
wherein in the preparing of the second metal sheet,
the plurality of heat dissipation fins are formed to protrude from a lower portion (246, Fig. 14, [0167]) of a flat portion (213 and 241 combined, Fig. 14) in contact with a lower surface of the ceramic base (Fig. 14, 213 is in contact with 211) at intervals (Fig. 14, 246 protrudes from 241 at intervals) and provided to be in contact with liquid refrigerant ([0152]),
wherein the flat portion has a multi-layer structure (241A and 241B, [0153]), the flat portion comprising:
an intermediate layer (213, [0154], [0155]);
an upper metal layer ([0155], bonding interface between 213 and 211) formed on an upper surface of the intermediate layer ([0155]); and
a lower metal layer (230, [0154]) formed on a lower surface of the intermediate layer,
the upper metal layer and the lower metal layer are made of the same metal material ([0154], [0155]),
the intermediate layer is made of a different metal material from the upper metal layer and the lower metal layer ([0151]), and
materials of the upper metal layer and the lower metal layer are Cu ([0154], [0155]).
Tonomura does not teach a material of the intermediate layer is any one of CuMo and Mo.
However, Kato teaches molybdenum layers (61 and 71, Fig. 8, [0036]) on both surfaces of a ceramic substrate (10, Fig. 8, [0036]), and one of the Mo layers (71) has heat radiation with copper fins ([0036]). Kato also teaches having a Mo layer on each surface of the ceramic substrate is effective in preventing the occurrence of warping, cracks, and the like of the ceramic substrate due to thermal stress generated in a high temperature heat cycle ([0039]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the intermediate layer (Tonomura: 213, “metal layer”) to use Mo because Mo is effective in preventing the occurrence of warping, cracks, and the like of the ceramic substrate due to thermal stress generated in a high temperature heat cycle (Kato: [0039]).
Regarding claim 10, Tonomura (third embodiment) teaches the bonding includes:
arranging a bonding layer between a lower surface of the first metal sheet and an upper surface of the ceramic base (224, [0161]) and between the lower surface of the ceramic base and the flat portion of the second metal sheet (225, [0162]).
Tonomura (third embodiment) does not teach brazing the first metal sheet, the ceramic base, and the second metal sheet by melting the bonding layer.
However, Tonomura (first embodiment) teaches a method first involving a Cu layer forming step ([0099], analogous to [0159]), where Cu is fixed to one surface of the metal plate (22, [0099], analogous to 222) serving as the circuit layer (12, [0099], analogous to 212) and also to one surface of the metal plate (23, [0099], analogous to 223) serving as the metal layer (13, [0099], analogous to 213).
The metal plate (22) is laminated so that the surface of the metal plate, on which the first Cu layer (24, [0102], analogous to 224, [0161]) is formed, faces the ceramic substrate (11, [0102]). Also, the metal plate (23) is laminated so that the surface of the metal plate, on which the second Cu layer (25, [0102], analogous to 225, [0162]) is formed, faces the ceramic substrate (11, [0102], analogous to [0162]).
Tonomura (first embodiment) additionally teaches Cu in the first Cu layer and the second Cu layer is diffused toward the metal plates and to form the first molten metal area (27, [0115]) and the second molten metal area (28, [0115]) to effect solidification, thereby bonding the ceramic substrate, the circuit layer, and the metal layer. Consequently, the ceramic substrate, the circuit layer, and the metal layer can be firmly bonded, even under relatively low temperature and in a short period of time ([0115]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Tonomura (third embodiment) with the method of Tonomura (first embodiment) to form molten area each with the first Cu layer (224) and the second Cu layer (225) to firmly bond the ceramic substrate (211), the circuit layer (212), and the metal layer (213) even under relatively low temperature and in a short period of time ([0115]).
Regarding claim 11, Tonomura teaches in the arranging of the bonding layer, the bonding layer made of a material including Ag ([0155]) is disposed by plating ([0207]).
Claim(s) 2 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tonomura (US 2013/010429), in view of Kato (JP 2011/230954), and further in view of Tomioka (US 2004/0042174).
Regarding claim 2, Tonomura does not teach the plurality of heat dissipation fins are disposed in a refrigerant circulation unit in which an internal flow path from an inlet to an outlet is formed and are in direct contact with the liquid refrigerant consecutively circulating along the internal flow path.
However, Tonomura teaches a cooling medium is circulated through the flow channels (242, [0152]). Tonomura additionally teaches the heat sink is formed with bonding the top board (241), the corrugated fins (246), and the bottom board (245) by brazing, which can be done simultaneously with bonding the heat sink and the power module substrate ([0175]). As a result, the manufacturing step of the substrate for a power module with a heat sink can be omitted, manufacturing cost can be reduced ([0175]).
Tomioka teaches a heat conduction case (27, Fig. 2, [0040], “refrigerant circulation unit”), where heat from a chip (23, Fig. 4, [0063]) is transmitted to a heat receiving surface (27a, Fig. 4, [0063]), and liquid coolant from circulation passages (33, [0040], “internal flow path”) absorbs much of the transmitted heat ([0063]). The heat conduction case also has a coolant inlet port (34, [0040], “inlet”), an outlet port (35, [0040], “outlet”), and fins (32, Fig. 2, [0040]) arranged in parallel. The fins form circulation passages, and the inlet port communicates with upper-stream ends of circulation passages while the outlet port communicates with lower-stream ends of circulation passages. Liquid coolant is sealed in the circulation passages ([0060]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the heat sink (Tonomura: 240) and ceramic substrate (Tonomura: 210, “power module substrate”) of Tonomura to be used as the heat conduction case (Tomioka: 27) and chip (Tomioka: 23) of Tomioka in order to reduce the manufacturing cost (Tonomura: [0175]) for the heat conduction case and chip used in Tomioka.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-11 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.
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 An Bach Phan whose telephone number is (571)272-7244. The examiner can normally be reached M-F, 7-3 ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Len Tran can be reached at (571)272-1184. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/A.B.P./Examiner, Art Unit 3763
/LEN TRAN/Supervisory Patent Examiner, Art Unit 3763
