DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
2. Applicants’ election without traverse of Group I (claims 1-7 and 19-22; “a thermal interface material (TIM)” and “a semiconductor package”) in the reply filed on 02/09/2026 is acknowledged.
3. Claims 8-18 and 23-25 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to nonelected inventions, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 02/09/2026.
Claim Objections
4. Claims 3 and 6-7 are objected to because of the following informalities:
As to Claim 3: The applicants are advised to add the term “the” before the claimed phrase “catalyst generator”.
As to Claim 6: The applicants are advised to delete the commas (,) after the claimed “1%” and “by weight”.
As to Claim 7: The applicants are advised to replace the claimed phrase “further comprising” with the new phrase “wherein the TIM further comprises”.
Appropriate corrections are required.
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.
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.
5. Claims 1-7 and 19-22 are rejected under 35 U.S.C. 103 as being unpatentable over Zhong (US 2005/0228097) in view of Trego (US 4,990,555) and Mizori (WO 2017/027482; utilized US 2018/0237668 as its Equivalent).
It is noted that Mizori (WO 2017/027482) is used for date purposes only, and all paragraphs cited below refer to its Equivalent, namely US 2018/0237668.
As to Claims 1-7 and 19-22: Zhong discloses a thermally interface material (TIM) (Paragraph [0014]) and a semiconductor packaging structure comprising the same (Paragraphs [0040] and [0042]). The TIM taught by Zhong comprises a curable composition (Paragraph [0008]) made of a curable resin such as a polydimethylsiloxane (Paragraphs [0023]-[0026]) and thermally conductive fillers (Paragraph [0019]).
While Zhong discloses the addition of at least one catalyst which may be selected from any group of catalysts compatible and blended with the curable resin (Paragraph [0031]), it does not specifically mention employing a catalyst generator that, when activated by a thermal stimulus, catalyzes cleavage of silicon-oxygen bonds in the hydroxy-terminated polysiloxane as required by the claims of the present application. Zhong also does not specify its polydimethylsiloxane as a hydroxy-terminated polysiloxane as required by claim 1 and its particular amount as required by claim 6.
Nevertheless, Trego teaches the use of hydroxy-terminated polysiloxanes that may be compounded into reaction mixture comprising a catalyst at temperatures greater than about 50°C, which is accompanied by significant cleavage of polysiloxane chains, to obtain a curable composition having advantageous curable properties (Col. 2, lines 19-65, Col. 3, lines 20-55, and see also abstract).
Furthermore, Mizori discloses the addition of salts used to form catalysts, including pyridine derivatives and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), which according to page 2, paragraph [0004] of the present specification corresponds to the claimed catalyst generator that, when activated by a thermal stimulus, catalyzes cleavage of silicon-oxygen bonds in hydroxy terminated polysiloxane, to a resin mixture containing polysiloxanes such as polydimethylsiloxanes, to prepare curable compositions having advantageous high temperature stability useful for semiconductor packaging (Paragraphs [0004], [0017]-[0018], [0050], [0057], [0175], [0187], and [0203]). Mizori also discloses that the salt forms catalysts in the reaction mixture at a temperature of at least 100 °C (Paragraph [0199]). Mizori further discloses that the salts used to form catalysts (catalyst generator) are used in an amount of 0.1-10% by weight (Paragraph [0175]), which overlaps with the amount of up to 1% by weight of the catalyst generator recited in present claim 6. See MPEP section 2144.05 (The subject matter as a whole would have been obvious to one having ordinary skill in the art at the time the invention was made, since it has been held that choosing the over lapping portion of the range taught in the prior art and the range claimed by the applicants has been held to be a prima facie case of obviousness.).
Given the above teachings, it would have been obvious to one of ordinary skill in the art to employ the hydroxy-terminated polysiloxanes blended or compounded with the claimed amount of salts used to form catalysts including pyridine derivatives and DBU (corresponding to the claimed catalyst generator that, when activated by a thermal stimulus, catalyzes cleavage of silicon-oxygen bonds in hydroxy terminated polysiloxane) suggested by Trego and Mizori in the curable composition of the TIM discussed in Zhong, with a reasonable expectation of successfully obtaining desired properties such as high temperature stability suitable for semiconductor packaging.
Correspondence
6. Any inquiry concerning this communication or earlier communications from the examiner should be directed to HANNAH J PAK whose telephone number is (571)270-5456. The examiner can normally be reached 8-5 PM; M-F.
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, Arrie Lanee Reuther, can be reached at (571)-270-7026. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/HANNAH J PAK/Primary Examiner, Art Unit 1764
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