PTAB

IPR2019-00147

Cooler Master Co. Ltd. v. Aavid Thermalloy LLC

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1. Case Identification

2. Patent Overview

  • Title: Integrated Circuit Heat Pipe Heat Spreader with Through Mounting Holes
  • Brief Description: The ’680 patent describes heat pipes, also referred to as vapor chambers, designed for cooling electronic components. The invention focuses on creating through-holes for mounting fasteners within the interior region of the heat pipe while maintaining the sealed integrity of the internal vapor chamber.

3. Grounds for Unpatentability

Ground 1: Obviousness over Nakamura - Claims 1-3 are obvious over Nakamura.

  • Prior Art Relied Upon: Nakamura (Japanese Unexamined Utility Model Application Publication, 1975).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Nakamura, which discloses a heat pipe with interior mounting holes, teaches every limitation of the challenged claims. Nakamura describes a sealed container made of two opposing metal plates enclosing a refrigerant and wick, which corresponds to the claimed boundary structure defining a vapor chamber. Crucially, Nakamura discloses forming "concavities" (depressions) in one plate that are bonded to the opposing plate to create an isolated "hole for component installation," which Petitioner asserted meets the limitations for a depression, spacer, and an isolated mounting hole that extends through both plates.
    • Motivation to Combine (for §103 grounds): This ground is based on a single reference. Petitioner asserted that all claimed features are present in Nakamura, making the invention obvious without combination.
    • Expectation of Success (for §103 grounds): Not applicable for a single-reference ground.

Ground 2: Obviousness over Nakamura and Takahashi - Claims 1-3 are obvious over Nakamura in view of Takahashi.

  • Prior Art Relied Upon: Nakamura (Japanese Unexamined Utility Model Application Publication, 1975), and Takahashi (Japanese Examined Utility Model Application Publication, 1991). The petition also lists Yamamoto (Patent 6,082,443) in the formal ground statement but does not provide substantive argument for its inclusion in the detailed analysis.
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that to the extent Nakamura alone does not teach every limitation, any missing elements would have been obvious to a person of ordinary skill in the art (POSITA) in view of Takahashi. The primary focus of this combination is the "peripheral lip" limitation. Petitioner argued that Takahashi’s disclosure of outward-protruding "flanges" at the periphery of its heat pipe plates, which are joined by vacuum brazing, explicitly teaches the structure and function of the claimed "lip."
    • Motivation to Combine (for §103 grounds): A POSITA would combine Nakamura and Takahashi as they address the same problem (cooling electronics with heat pipes having mounting holes) and are thus analogous art. Both references describe similar manufacturing processes involving pressing and brazing metal plates. Petitioner contended a POSITA would be motivated to incorporate Takahashi's peripheral flanges into Nakamura's design to make the edge-sealing process easier and more reliable, as the outward-facing flanges are easier to clamp and braze.
    • Expectation of Success (for §103 grounds): A POSITA would have a high expectation of success because combining the well-known manufacturing techniques and structural features from Nakamura and Takahashi would involve straightforward engineering principles and yield predictable results.

4. Key Claim Construction Positions

  • "Vapor Chamber": Petitioner proposed the construction "enclosed and sealed space or cavity in which a heat transfer fluid is present to be evaporated (or vaporized) and condensed to transport or spread heat." This challenges the Patent Owner's proposed construction, which requires the chamber to be "vacuum sealed" and that "capillary forces are utilized." Petitioner argued that "vacuum" is ambiguous and confusing, whereas "enclosed and sealed" is more accurate. It also argued that the use of capillary forces (via a wick) is an optional feature in heat pipes and should not be a required limitation for the general term.
  • "Lip": Petitioner proposed the construction "portion of the plate comprising a region bonded to another plate." This was argued to be a broad but accurate interpretation based on the specification. Petitioner contended the Patent Owner's proposed construction, which defined the lip by the "bonded region of the plate's inner or interior surface," was self-contradictory because the bonded region is at the periphery and is no longer an "inner" surface once sealed.
  • "Spacer": Petitioner proposed the construction "structure used to maintain a space or clearance between the plates." Petitioner argued the Patent Owner improperly sought to add negative limitations, such as requiring the spacer to be "apart from the separately claimed depression" and to "provide support for a capillary wick." Petitioner pointed to the specification, which states that spacers can be "embossed depressions," and to the existence of wickless heat pipes in the prior art, to argue these additional limitations are incorrect.
  • "Hollow Column": Petitioner accepted the Patent Owner's proposed construction of "a columnar structure defining an unfilled or empty space" for the purposes of the petition.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §325(d) would be inappropriate. The core reason provided was that the petition relies on new prior art and grounds of unpatentability. Specifically, Petitioner stated that none of the prior art references relied upon in its invalidity challenges (Nakamura, Takahashi, Yamamoto) were cited or considered during the original prosecution of the ’680 patent.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review of claims 1-3 of Patent 7,100,680 and a final determination that those claims are unpatentable.