DETAILED ACTION
Examiner’s Note
The Examiner acknowledges the cancelation of claims 5 and 8 in the amendments filed 4/1/2026.
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 .
Rejections
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim Rejections - 35 USC § 103
Claim(s) 1-4, 6-7, 9 and 13-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Takamoto et al. (US 2016/0042986 A1) in view of Wenfeng et al. (JP 2021125516 A) and in further view of Kondo et al. (US 2013/0237017 A1); and in light of the evidence provided via Kurooka et al. (US 10249563 B2). The Examiner notes that citations from the ‘516 reference were taken from a machine translation, which is included with the current action.
Regarding claim(s) 1-4, Takamoto teaches a reinforcing sheet (8) comprising a thermosetting resin layer (2) for mounting a semiconductor device (10), which is disposed on a backside grinding tape (1) comprising a pressure-sensitive adhesive (PSA) layer (1b) and a base material layer (1a) (PSA sheet) towards processing a primary mounted semiconductor device (temporary fixing an electronic device) (para 0037-0041; Fig.1 and Figs. 2A-2D). Takamoto also teaches that the PSA layer (1b) (para 0051) is an acryl-based PSA comprising an acryl-based polymer (para 0054).
Takamoto does not disclose a coefficient of thermal expansion (CTE) for the PSA layer (1b). However, Takamoto does contemplate the inclusion of filler in the PSA layer (1b) (para 0070).
In addition, Wenfeng teaches a PSA sheet for manufacturing a semiconductor device exposed to temperatures of 150 to 250 ℃ comprising a substrate (e.g., a heat-resistance substrate) and a PSA layer provided thereon, wherein the substrate has a thermal expansion coefficient of 5 to 50 ppm/℃ (i.e., 5 to 50 ×10-6/℃, or 5 ×10-6/℃ to 5.0 ×10-5/℃) at 150 to 250 ℃ (para 0011). The Examiner notes that the /℃ is identical to /K as the two temperature units represent increments in the temperature and the interval between ℃ is identical to the interval between degrees kelvin (i.e., D℃ = DK).
Thus, Wenfeng teaches that the heat-resistant substrate comprises a thermal expansion coefficient of 5 ×10-6/K to 5.0 ×10-5/K, which overlaps with the presently claimed lower limit of 1 ×10-5/K for the presently recited PSA layer at 150 to 250 ℃. As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Wenfeng also teaches that the thermal expansion coefficient of the PSA layer is adjusted via the inclusion of filler (para 0019).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to adjust the filler proportions in the PSA layer of Takamoto for the intended application since it has been held that discovering an optimum value of a result-effective variable involves only routine skill in the art (In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980)) to provide the PSA layer of Takamoto with the presently claimed thermal expansion coefficient (1 to 500 ×10-5/K) at the presently claimed temperature range (200 to 210 ℃, and 230 to 240 ℃) towards the prevention of warpage of the reinforcing sheet (8) as in the present invention. See Kurooka at column 10, lines 14-20, which discusses warpage when two joined layers have different thermal expansion coefficients.
Takamoto/Wenfeng teaches the reinforcing sheet (8) comprising the PSA layer (1b) as set forth above, but is silent to the presently claimed and gel fraction (93 to 99.99%); and to the storage modulus (current claim 3) and 5% weight loss temperature (current claim 4).
However, Kondo teaches a PSA tape for semiconductor production (para 0061) comprising as acrylic PSA layer (para 0072, 0077) comprising:
a gel fraction of 60 % or more (para 0082) such as 97.8% (para 00250), which is adjusted via the degree of crosslinking (para 0084);
a storage modulus at 200 ℃ of 5.0 × 104 to 1.0 × 107 Pa (0.05 MPa to 10 MPa) towards a balance of sufficient wire bondability and adhesive force (para 0133-0134);
and a 5% weight loss temperature of 250 ℃ or higher which is adjusted via the degree of crosslinking and removing low-molecular weight components (para 0120-0121) such as 330 ℃ (para 0193).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to adjust crosslinking density (and gel fraction), storage modulus and weight loss temperature to that presently claimed based on the gel fraction; the balance of wire bondability and adhesive force; and the acceptable weight loss % at the temperature of use required of the prior art’s intended application as in the present invention.
Regarding claims 6-7 and 9, Takamoto does teach that the acryl-based polymer comprises:
one or more (meth)acrylic acid alkyl esters such as, inter alia, n-butyl acrylate and 2-ethylhexyl acrylate (para 0055), which are identical to those presently disclosed as comprising the presently claimed acrylic polymer (see, for example, para 0022 presently disclosed);
copolymerized monomers towards modifying heat resistance, cohesion, etc. such as, inter alia, carboxyl group-containing monomers such as acrylic acid (AA) and hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate (2-EHA) (para 0056), both of which are identical to those presently claimed (current claim 6, current claim 7) and presently disclosed (see, for example, para 0023 presently disclosed);
and polyfunctional monomers towards crosslinking such as, inter alia, trimethylolpropane triacrylate (para 0057), which is identical to that presently claimed polyfunctional monomer (current claim 9).
Takamoto continues to teach that the PSA comprises external crosslinkers such as, inter alia, polyisocyanate compounds and epoxy compounds for increasing the number-average molecular weight (Mn) of the acryl-based polymer (400000 to 3000000) (para 0058-0059), which said polyisocyanate compounds and epoxy compounds are identical to the presently claimed epoxy-based crosslinking agent (current claim 6) and isocyanate-based crosslinking agent (current claim 7).
Regarding claim(s) 13-14, as noted above, Takamoto teaches the reinforcing sheet (8) comprising a pressure-sensitive adhesive (PSA) layer (1b) and a base material layer (1a). The invention is directed towards mounting a flip-chip (para 0037).
Claim(s) 10-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Takamoto et al. (US 2016/0042986 A1) in view of Wenfeng et al. (JP 2021125516 A) and in further view of Kondo et al. (US 2013/0237017 A1) and Yutou et al. (US 2015/0259576 A1).
Regarding claim(s) 10-11, Takamoto/Wenfeng/Kondo teaches the reinforcing sheet (8) comprising the PSA layer (1b) as set forth above, but is silent to the PSA further comprising the presently claimed diocytltin dilaurate cross-linking catalyst.
However, Yutou teaches a PSA tape for semiconductor processing comprising a PSA layer (para 0017-0020) comprising a crosslinking reaction catalyst such as, inter alia, dioctyltin dilaurate (para 0105).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to provide the PSA of Takamoto/Wenfeng/Kondo with the presently claimed catalyst towards adjusting the rate of the crosslinking reaction as in the present invention.
Claim(s) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Takamoto et al. (US 2016/0042986 A1) in view of Wenfeng et al. (JP 2021125516 A) and in further view of Kondo et al. (US 2013/0237017 A1) and Kakiuchi et al. (US 2018/0286736 A1).
Regarding claim(s) 12, Takamoto/Wenfeng/Kondo teaches the reinforcing sheet (8) comprising the PSA layer (1b) comprising the acryl-based polymer having a number-average molecular weight (Mn) of 400000 to 3000000 as set forth above, but is silent to said acryl-based polymer having a weight-average molecular weight (Mw) of 600,000 to 1,600,000.
However, Kakiuchi teaches a PSA acrylic polymer having a Mw of 400,000 to 900,000, which overlaps that presently claimed, towards a balance of cohesion and residue prevention, coatability and adhesion (para 0058). Kakiuchi also teaches that the molecular weight distribution (Mw/Mn) is 3.0 or less towards the prevention of residue (para 0059).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to provide the acryl-based polymer with the present claimed Mw towards the resultant PSA layer demonstrating a balance of cohesion and residue prevention, coatability and adhesion as in the present invention.
Response to Arguments
Applicant's arguments, see the claim amendments and the remarks filed 4/1/2026, with respect to the rejections of claims 1-2, 6-9 and 13-14 over Takamoto et al. in view of Wenfeng et al. under 35 U.S.C. 103; claims 3-5 over Takamoto et al. in view of Wenfeng et al. and in further view of Kondo et al. under 35 U.S.C. 103; claims 10-11 over Takamoto et al. in view of Wenfeng et al. and in further view of Yutou et al. under 35 U.S.C. 103; and claim 12 over Takamoto et al. in view of Wenfeng et al. and in further view of Kakiuchi et al. under 35 U.S.C. 103 as set forth in paragraphs 4-7 of the action mailed 1/2/2026, have been fully considered but they are not persuasive.
The Examiner acknowledges that the Kondo reference does not discuss or suggest that the disclosed acrylic copolymer comprises a polyfunctional monomer as presently claimed, nor the polyfunctional monomer comprising the disclosed acryl-based polymer of the Takamoto PSA. However, the Examiner respectfully reminds the Applicant that (Examiner’s emphasis),
the "test for obviousness is not whether the features of a secondary reference may be
bodily incorporated into the structure of the primary reference... Rather, the test is what
the combined teachings of the references would have suggested to those of ordinary skill
in the art", In re Keller, 642 F.2d 413,208 USPQ 871,881 (CCPA 1981) and that
"combining the teachings of references does not involve an ability to combine their
specific structures", In re Nievelt, 482 F.2d 965, 179 USP 224, 226 (CCPA).
In addition, as set forth in the previous and current prior art rejections, the cited portion of the Takamoto reference (para 0057) instructs that the acryl-based polymer comprises said polyfunctional monomer towards crosslinking. The analogous Kondo specifically instructs one skilled in the art that said crosslinking provides a means for adjusting the gel fraction of a PSA (see, for example, para 0084 therein). Thus, it is the combination of the disclosures of Takamoto and Kondo that renders obvious the presently claimed gel fraction.
Turning now to the Applicant’s assertions of the synergy between the presently claimed PSA comprising an acrylic polymer comprising a polyfunctional monomer, and the PSA layer demonstrating a gel fraction of 93 to 99.99%, the Examiner first notes that the presently recited 5% weight is not included in independent claim 1. In addition, the Examiner respectfully submits that the presently disclosed data does not provide persuasive evidence of the alleged synergy.
For example, inventive examples 1-4 and 9-10 all comprise polyfunctional monomer (TMPTA) and at least one crosslinkable monomer (AA and/or HEA); wherein inventive examples 5-8 and comparative examples 1-2 do not contain said polyfunctional monomer, but inventive example 5 comprises (AA) at 5.0 %, inventive example 6 comprises (AA) at 9.1 %, inventive examples 7-8 comprise (HEA) at 3.7 %, comparative example 1 comprises (AA) at 9.1 %, and comparative example 2 comprises (HEA) at 3.7 %. All of inventive examples 1-3 and 5-10 and comparative example 1 demonstrate gel fractions within the presently claimed range; with inventive example 4 and comparative example 2 demonstrating gel fractions outside said range.
Thus, there does no appear to results consistent with evidencing the synergy between both the presently claimed polyfunctional monomer and the gel fraction. For example, inventive example 4 is outside the claimed gel fraction, but has a 5% weight loss within the claimed temperature range of 320 to 400 ℃. Inventive example 5 has a gel fraction within the claimed range but does not comprises a polyfunctional monomer, and still demonstrates a 5% weight loss within the claimed temperature range of 320 to 400 ℃. Similarly, all the inventive example, with or without an acrylic polymer comprising TMPTA, demonstrate a CTE within the presently claimed range of 1 to 500 × 10-5/K. Thus, it is unclear from the data whether the presence of the polyfunctional monomer and the presently claimed gel fraction are indeed critical towards providing the synergetic effects presently argued.
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 FRANK D DUCHENEAUX whose telephone number is (571)270-7053. The examiner can normally be reached 8:30 PM - 5:00 PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Alicia A Chevalier can be reached at 571-272-1490. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/FRANK D DUCHENEAUX/Primary Examiner, Art Unit 1788 4/27/2026
Prosecution Insights