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
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 and 6-10 are rejected under 35 U.S.C. 103 as being unpatentable over Endo et al. (JP 2020-164894 A, see attached translation, hereafter “Endo”).
Regarding claims 1 and 10, Endo discloses a method for producing a joined body in which a first joining target and a second joining target are joined with a joining layer interposed between the first joining target and the second joining target [0016], the method comprising: a step of applying a paste that contains copper particles [0014, 0027] and an organic solvent [0037-0038] to the first joining target (metal substrate) to form a coating film [0015, 0046]; a step of placing the second joining target (semiconductor element- [0048]) on the coating film to form a stack [0016-0017]; and a sintering step of heating and pressing the stack to sinter the copper particles contained in the coating film to form the joining layer [0053], wherein, in the sintering step, the heating is performed incrementally from a heating start temperature to a highest temperature (e.g. sintering temperature 280°C [0054]), and the pressing is performed incrementally from a pressing start pressure to a highest pressure, and control is performed in such a manner that a pressing pressure is 5 MPa or less [0056] (meets 15 MPa or less) when a heating temperature reaches 200°C. Examiner notes that any manner of increasing temperature & pressure meets ‘incrementally’- present claims are not limited to particular timing conditions. The sintering temperature and pressure conditions in the method of Endo falls within the recited ranges. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), MPEP 2144.05.
As to claims 6-7, Endo discloses that the highest temperature Tm is 280°C [0054], which meets the recited range of 200-350°C, and holding at this constant temperature for about 10-60 minutes for bonding strength [0055].
As to claims 8-9, Endo discloses that the highest pressure is 5 MPa [0054], which meets the recited range of 1-40 MPa, and holding at this constant pressure for about 10-60 minutes during sintering for bonding strength [0055].
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Endo et al. as applied to claim 1 above, and in view of Hiratsuka et al. (US 2015/0069638, hereafter “Hiratsuka”).
As to claim 2, Endo does not specifically show that the coating film extends from peripheral edges of the second joining target when the second joining target is placed on the coating film. However, such arrangement is known in the sintering art. Analogous to Endo, Hiratsuka is also drawn to metallic paste for bonding semiconductor devices such as power device (abstract, [0003]). Hiratsuka shows that a bonding/coating film 6 is applied in such a manner that the coating film 6 has dimensions that the coating film extends from peripheral edges of the second joining target 5 (SiC chip) when the second joining target is placed on the substrate 7 (see fig. 8, [0090]); the coating film/paste is formed into a size and shape suitable for the bonding portion [0064]. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to provide a coating film extending from peripheral edges of the second joining target in the joining method of Endo with a motivation to ensure sufficient coverage of the joining layer at the interface.
Claims 3-5 are rejected under 35 U.S.C. 103 as being unpatentable over Endo et al. as applied to claim 1 above, and in view of Jo et al. (The properties of Cu sinter paste for pressure sintering”, IEEE conference, 2019, see attached NPL, hereafter “Jo”).
As to claims 3-4, Endo is silent with respect to the sintering step not including a constant temperature process for 10 seconds or more from the heating start temperature to the highest temperature. However, such continuous heating is known in the art. Jo (NPL- also directed to sintering using metal paste- abstract) teaches copper paste for pressure sintering (pg. 76), wherein the sintering step gradually heats from room temperature (RT) to 280°C in 2 min and does not include a constant temperature process for 10 seconds or more from a start temperature (RT) to the highest temperature 280°C (see fig. 4). After reaching 280°C, Jo teaches applying 9 MPa pressure under nitrogen for sintering for 5 minutes (pg. 77). In this manner, highest pressure is applied after reaching the highest temperature. Consequently, Jo discloses that the copper paste sintering achieves high shear strength without oxidation (pg. 76- top right column). Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to apply temperature & pressure in similar manner to Jo in the method of Endo in order to achieve desired shear strength.
As to claim 5, Jo does not disclose applying a constant pressure step for 10 seconds or more from the pressing start pressure to the highest pressure. It is noted this negative limitation is satisfied in the combination of Endo & Jo above.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 7/16/25, 8/8/24 complies with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Inquiry
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DEVANG R PATEL whose telephone number is (571) 270-3636. The examiner can normally be reached on Monday-Friday 8am-5pm, EST.
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/DEVANG R PATEL/
Primary Examiner, AU 1735
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