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 .
Specification
The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant's cooperation is requested in correcting any errors of which applicant may become aware in the specification.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 12/06/2023,02/05/2024,03/13/2024,08/12/2024,03/03/2025 and 07/23/2025 is being considered by the examiner.
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.
Claim(s) 1-21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kazem et al, US 10777483 B1 in view of Kataria et al, (EP 1300 883 A2) and Berghoff Gerhard et al, WO 02/069685 A1.
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Pertaining to claim1, 20, Kazem teaches ( see fig.2A and 3A above) an assembly comprising: a die (integrated circuit 208, Fig. 2A, B); an upper layer (upper layer 210); and a thermal interface material (TIM 204) disposed in contact with the die layer and the upper layer, wherein the thermal interface material comprises a polymer, liquid metal droplets (section summary: "The thermal interface material applied to the die comprises an emulsion of liquid metal droplets and uncured polymer.") the liquid metal droplets are in a liquid phase at least at a temperature in a range of - 20 degrees Celsius to 30 degrees Celsius (col. 41. 25 ff: "The liquid metal can be in the liquid phase at least at a temperature in a range of -20 degrees Celsius to 30 degrees Celsius").
Kazem is silent about the thermal interface material also comprises rigid particles, a bondline distance between the die and the upper layer is 95% to 125% of the average particle size of the rigid particles, the liquid metal droplets have a first aspect ratio and the rigid spheres have a second aspect ratio, wherein the first aspect ratio is greater than the second aspect ratio.
However , in the same filed of endeavor, Kataria teaches to use a TIM comprising physical barrier elements 20, e.g. in the form of rigid glass beads (Fig. 1). These physical barrier elements 20 act to provide a minimum distance between the heat generating component 12 and the heat sink 14 (Kataria, par. 12).
In view of Kataria, it would have been obvious to one of ordinary skill in the art to introduce such physical barrier elements in the TIM of Kazem. Kataria does not disclose the size of the glass beads. However, choosing the optimal size of the glass beads appears to be a matter of routine experimentation, which the skilled person can perform without undue effort, Moreover, Berghoff Gerhard, teaches to use incompressible glass spheres of 100 - 200 µm in diameter as spacers (p. 81. 25). Since in Kazem , the liquid droplets may have a diameter of up to 200 µm (col. 51. 15 ff, notably I. 35), the liquid droplets would be squeezed when spherical glass spacers with a diameter of less than 200 µm, e.g. 100 µm, would be used, which would also lead to the requirement that the liquid droplets have an aspect ratio that is greater than that of the spheres and further "the rigid particles can enable effective control of the bondline distance and applying the rigid particles prior to applying the emulsion of the polymer and liquid metal droplets can enable effective control of the bondline distance" (descr., par. 7 of Kazem ).
Pertaining to claim 6-7,19,21, Kazem in view of Kataria and Berghoff Gerhard teach most of the limitation of the claims, wherein Berghoff Gerhard teaches the TIM is applied with the glass-spheres already mixed into it (p. 91. 10, 11), further wherein the method in claim 21 appears to be a combination of the method in claim 6 and claim 7 which is also been rejected by Berghoff Gerhard.
Pertaining to claim 2 and 12, Kazem teaches ( see fig.2A and 3A above) the additional feature that the liquid metal for the TIM can comprise gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, a mercury alloy, or a combination thereof (D1, col. 41, 7 ff), and , Kataria and Berghoff Gerhard further teach that the materials of the particles acting as spacers can be glass (Kataria, par, 12; or Berghoff Gerhard, p. 31. 19); and because Berghoff Gerhard discloses that it can be ceramics (Berghoff Gerhard, p. 31. 19).
Pertaining to claim 3 and 13 Kazem in view of Kataria and Berghoff Gerhard teach most of the limitation of the claims, wherein Kataria or Berghoff Gerhard each disclose that the materials of the particles acting as spacers can be glass (Kataria, par, 12; or Berghoff Gerhard, p. 31. 19), which usually has a Young's modulus in the GPa range, i.e. well above 100 MPa.
Pertaining to claim 4 and 17, Kazem teaches ( see fig.2A and 3A above) the amount of liquid metal droplets can be from 1% to 90 % (col. 41. 63 to col. 51. 15) and Berghoff Gerhard discloses the additional feature that the amount of glass beads is 0.5% bis 5% (Berghoff Gerhard, p. 31. 23), i.e. is in the range of 0.1 to 5%.
Pertaining to claim 5,10 and 18, Kazem in view of Kataria and Berghoff Gerhard teach most of the limitation of the claims, wherein Kataria and Berghoff teach that the thickness of the TIM material is only slightly larger than the size of the rigid particles acting as spacers, which would lead to the average heights of the particles as claimed.
Pertaining to claim 8, Kazem teaches ( see fig.2A and 3A above) that the thickness of the TIM can be 150 µm (Kazem , col. 8 I. 67).
Pertaining to claim 9, Kazem teaches ( see fig.2A and 3A above) that the glass spheres have a diameter of 100 - 200 µm (p. 81. 25), i.e. overlapping the range of 1 to 150 µm.
Pertaining to claim 11, Kazem in view of Kataria and Berghoff Gerhard teach most of the limitation of the claims, wherein Kataria and Berghoff teach the rigid particles are spheres (Kataria, Fig. 1, glass beads, par. 5; Berghoff Gerhard , p. 8 I. 23, 24).
Pertaining to claim 14, Kazem in view of Kataria and Berghoff Gerhard teach most of the limitation of the claims, wherein Kataria or Berghoff Gerhard teach that particles with a size distribution as uniform as possible, which would lead to choosing a D₉₀ no greater than 125% of the D₅₀ of the rigid particles.
Pertaining to claim 15, Kazem teaches ( see fig.2A and 3A above) that the die can be a processor (col. 9 I. 49).
Pertaining to claim 16, Kazem teaches ( see fig.2A and 3A above) based on claim1 that it would lead to the compressed liquid droplets being ellipsoidal.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. See PTO 892.
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/MAMADOU L DIALLO/Primary Examiner, Art Unit 2897
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