PTAB

IPR2015-01276

Asetek Danmark AS v. CoolIT Systems Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Fluid Heat Exchanger Configured to Provide a Split Flow
  • Brief Description: The ’330 patent discloses a fluid heat exchanger for cooling electronic components. The technology utilizes a split-flow arrangement through a plurality of parallel microchannels to reduce fluid pressure drop and improve thermal efficiency.

3. Grounds for Unpatentability

Ground 1: Obviousness over Kang and Bonde - Claims 1-8, 21, 24, and 26 are obvious over Kang alone or in view of Bonde.

  • Prior Art Relied Upon: Kang (Application # 2006/0096738) and Bonde (Patent 5,099,311).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Kang discloses a fluid heat exchanger comprising nearly all claimed elements, including a cooling plate with fins defining channels, a housing, inlet and outlet headers, and a flow distributor plate that creates multiple split-flows. To the extent Kang's channels were not explicitly "microchannels" or certain manifold arrangements were not disclosed, Petitioner asserted that Bonde supplied these teachings. Bonde was cited for its disclosure of a heat sink with parallel microchannels, a centrally located inlet manifold positioned between two outlet manifolds, and fluid openings that extend into each microchannel.
    • Motivation to Combine: A POSITA would combine Kang and Bonde because both references are in the field of split-flow heat exchangers for cooling electronics and address identical technical problems. Petitioner contended that modifying Kang's design with Bonde's explicit microchannel structure would be a predictable way to maximize heat transfer efficiency, a primary goal in the art.
    • Expectation of Success: Petitioner argued that a POSITA would have had a reasonable expectation of success in combining the references because Kang already taught the fundamental components. Incorporating Bonde's more defined microchannel and manifold features was presented as a straightforward, predictable modification.

Ground 2: Obviousness over Kang, Bonde, and Philpott - Claims 9-11 are obvious over Kang in view of Bonde and further in view of Philpott.

  • Prior Art Relied Upon: Kang (Application # 2006/0096738), Bonde (Patent 5,099,311), and Philpott (Patent 6,827,128).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground adds Philpott to the Kang/Bonde combination to teach the additional limitations of dependent claims 9-11. Petitioner argued Philpott discloses a microchannel heat exchanger where the channels have varying lengths to form a "scalloped" or "hourglass" shape at their ends. This configuration results in larger fluid outlet openings for the centrally-located microchannels compared to those at the periphery, which Petitioner mapped directly to the claim limitations requiring a "scalloped edge" and differential outlet sizes.
    • Motivation to Combine: A POSITA would add Philpott's teachings to the Kang/Bonde system to further reduce pressure drop and improve flow uniformity through the central microchannels where heat transfer is most critical. This was argued as a logical step in optimizing the performance of a split-flow heat exchanger.
    • Expectation of Success: Petitioner asserted that success was expected because modifying the outlet grooves of a base design like Bonde's to be "scalloped," as taught by Philpott, was a simple design modification that would predictably improve the heat exchanger's overall performance by reducing flow resistance.

Ground 3: Obviousness over Kang and Bhatti - Claims 12, 14, 15, 18-20, 22, 23, 25, 27, and 28 are obvious over Kang in view of Bhatti.

  • Prior Art Relied Upon: Kang (Application # 2006/0096738) and Bhatti (Application # 2007/0163750).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that the combination of Kang and Bhatti renders independent claims 12 and 14, along with their dependents, obvious. While Kang provides the basic heat exchanger structure, Bhatti was cited for its clear disclosure of a heat sink with an inlet plenum on one side of the microchannels and an outlet plenum on the "opposite" side. This was argued to directly teach the key limitation of having the inlet and outlet header regions on opposite sides of the fins.
    • Motivation to Combine: A POSITA would combine the references because both concern split-flow heat exchangers. Petitioner contended that placing header regions on opposite sides of the microchannels, as taught by Bhatti, was a well-known design choice. A POSITA would have been motivated to implement this known configuration in Kang's system to achieve a common and effective flow arrangement.
    • Expectation of Success: Petitioner argued that modifying Kang's inlet and outlet regions to be opposite each other based on Bhatti's teaching would be a simple matter of design choice for a POSITA, achievable without undue experimentation to yield predictable results.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 4) for claims 13, 15, and 16 based on the four-way combination of Kang, Bhatti, Bonde, and Philpott, relying on similar design modification theories.

4. Key Claim Construction Positions

  • Petitioner proposed that the claim terms "fluid inlet opening," "aperture," and "inlet to the microchannels" should be construed to mean "one or more passages on the plate that provide fluid flow from the inlet header into the plurality of microchannels."
  • Likewise, Petitioner proposed that "fluid outlet opening" and "outlet to the microchannels" should be construed to mean "one or more passages on the plate that provide fluid flow from the plurality of microchannels to the outlet header."
  • These constructions were based on the ’330 patent’s specification, which states that although a single opening is shown, multiple openings may be used. The constructions were argued as critical for mapping prior art references like Kang, which disclose multiple inlet and outlet openings, to the challenged claims.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-28 of the ’330 patent as unpatentable.