PTAB

IPR2018-00049

Laird Technologies Inc v. Parker Intangibles LLC

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1. Case Identification

2. Patent Overview

  • Title: Thermally or Electrically-Conductive Form-In-Place Gap Filler
  • Brief Description: The ’192 patent discloses a method for filling a gap between two surfaces using a fluent, form-stable compound. The core of the invention is that the compound, an admixture of a polymer gel and a particulate filler, is substantially fully cured before it is dispensed from an orifice to fill the gap.

3. Grounds for Unpatentability

Ground 1: Claims 1-9 and 11-17 are obvious over Vyas in view of Kalinoski

  • Prior Art Relied Upon: Vyas (Patent 5,348,686) and Kalinoski (Patent 6,096,413).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Vyas taught the key composition of claim 1 by disclosing an electrically conductive, cross-linked (i.e., cured) silicone gel mixed with conductive particulate fillers (silver flakes and silver-coated mica). Vyas explicitly described this compound as "dispensable" (fluent) and "non-flowing" (form-stable) in its cured state, meeting the primary limitations of the claimed compound. Petitioner asserted that Kalinoski taught the claimed method of application by disclosing a standard apparatus for dispensing a silicone gel mixed with conductive fillers through a nozzle (orifice) under pressure to form an in-place EMI shielding gasket, thereby filling a gap between substrates.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to apply the pre-cured, dispensable gel of Vyas using the well-known and conventional dispensing system described in Kalinoski. Using a standard dispensing gun is a routine and efficient method for applying such materials, and using a pre-cured gel would save users the time and complexity of post-application curing.
    • Expectation of Success: Because Kalinoski’s method was a standard technique for applying similar conductive gel materials, a POSITA would have had a high expectation of successfully dispensing the Vyas composition in the same manner to fill a gap for EMI shielding.

Ground 2: Claims 1-13 and 17 are obvious over Sawa in view of Kalinoski

  • Prior Art Relied Upon: Sawa (Patent 5,227,081) and Kalinoski (Patent 6,096,413).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Sawa disclosed a thermally conductive silicone grease made by mixing a "cured organosiloxane gel" with a thickener, such as alumina or boron nitride powder (a particulate filler). Sawa taught that the resulting composition was a highly viscous, form-stable, and dispensable material, thereby teaching the compound of claim 1. As in Ground 1, Kalinoski was relied upon for its disclosure of a routine method for dispensing similar gel-like compounds to form a gap-filling gasket.
    • Motivation to Combine: A POSITA would have been motivated to use the pre-cured, thermally conductive mixture from Sawa with the standard dispensing method taught by Kalinoski. This combination would achieve a process where the gap-filling material does not require curing after delivery, offering a clear advantage in efficiency and time savings for the end-user, a known goal in the art.
    • Expectation of Success: A POSITA would have reasonably expected that Sawa's thermally conductive grease, a gel-like compound, could be successfully applied using the conventional dispensing techniques for gels and gaskets shown in Kalinoski.

Ground 4: Claims 1-2, 4-9, and 17 are anticipated by Aakalu

  • Prior Art Relied Upon: Aakalu (Patent 4,265,775).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued Aakalu anticipated every element of claim 1. Aakalu disclosed a "non-bleeding thixotropic thermally conductive material" that is fluent when applied under pressure but form-stable ("maintains a jelly-like form") once pressure is removed. The composition was an admixture of a liquid silicone carrier, a thermal filler powder (particulate filler), and silica fibers. Petitioner argued that the interaction between the silica fibers and silicone oil created a stable network that qualified as a "cured polymer gel" under the broad definition provided in the ’192 patent itself. Aakalu further disclosed that this compound is applied via a "small injection nozzle" (orifice) under pressure to fill a gap between an integrated circuit and a cap, teaching the claimed method steps. The compound's non-reactive ingredients and pre-formed network meant no further appreciable curing occurred after dispensing.

  • Additional Grounds: Petitioner asserted numerous additional obviousness grounds. These included challenges based on Nguyen (Patent 6,673,434) and Ellsworth (Application # 10/213,673), both of which taught pre-cured thermal interface materials, in combination with secondary references like Kalinoski or Aakalu for dispensing methods. Other grounds targeted specific dependent claims by combining primary references with art teaching specific filler conductivities (Misra, Shikata) or other known properties.

4. Key Claim Construction Positions

  • "polymer gel": Petitioner argued that the patent’s specification explicitly broadened this term beyond conventionally cross-linked gels to encompass "pseudogels or gel-like" substances having similar viscoelastic properties, such as those with a "loose" cross-linking network. This construction was critical for asserting that Aakalu's silica fiber network met the claim limitation.
  • "admixture of: (I) a cured polymer gel component and (II) a particulate filler component": Petitioner contended this phrase means the final mixture as a whole is in a cured state, and does not require a specific sequence of first curing the gel and then mixing it with the filler. The patent’s description of curing during or after mixing supported this interpretation, which was central to how the prior art was alleged to meet the claim.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-17 of Patent 7,208,192 as unpatentable.