Cooler Master Co Ltd v. Aavid Thermalloy LLC

1. Case Identification

• Case #: IPR2019-00334
• Patent #: 7,100,680
• Filed: November 14, 2018
• Petitioner(s): Cooler Master Co., Ltd.
• Patent Owner(s): Aavid Thermalloy LLC.
• Challenged Claims: 1-3

2. Patent Overview

• Title: Integrated Circuit Heat Pipe Heat Spreader with Through Mounting Holes
• Brief Description: The ’680 patent discloses heat pipes, also known as vapor chambers, designed for cooling electronic components. The invention describes techniques for creating through-holes for mounting fasteners that pass through the body of the heat pipe without compromising the sealed integrity of the internal vapor chamber.

3. Grounds for Unpatentability

Ground 1: Obviousness over Morikawa - Claim 2 is obvious over Morikawa.

• Prior Art Relied Upon: Morikawa (Japanese Examined Utility Model Application Publication No. S53-32387 Y).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Morikawa, which discloses a panel-type heat pipe with through-holes for mounting components, teaches all limitations of claim 2. Morikawa’s structure includes a first plate and a second plate forming an airtight enclosure, which Petitioner mapped to the claimed vapor chamber. The “metal pipe 11a” in Morikawa, which creates a sealed through-path for a mounting bolt, was argued to be the claimed “hollow column” that is integral with the first plate and projects outwardly. Petitioner asserted that the requirement for the plates to have circumferential edge lips bonded together is inherently disclosed, as an airtight enclosure requires its constituent plates to be sealed at their periphery.
  • Key Aspects: This ground asserted that a single prior art reference rendered the claim obvious, arguing that all structural elements were present or would have been obvious implementations to a Person Having Ordinary Skill in the Art (POSITA).

Ground 2: Obviousness over Morikawa in view of Takahashi - Claim 2 is obvious over Morikawa in view of Takahashi.

• Prior Art Relied Upon: Morikawa (Japanese Examined Utility Model Application Publication No. S53-32387 Y) and Takahashi (Japanese Examined Utility Model Application Publication No. H8-10205).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground relied on the same core teachings from Morikawa as Ground 1 but added Takahashi to more explicitly teach the “circumferential edge lip” limitation. Petitioner argued that while Morikawa’s plates are sealed at their edges, the specific edge structure is not detailed. Takahashi explicitly discloses forming a heat pipe container by joining two plate members with peripheral “flanges (17)” using a vacuum brazing method.
  • Motivation to Combine: A POSITA would combine Takahashi’s flange design with Morikawa’s heat pipe to improve manufacturability. Petitioner contended that Morikawa’s design, which appears to join the plates perpendicularly, would be difficult to bond reliably. Takahashi’s flange design allows the plates to be joined in parallel, making it easier for clamping tools to access and apply pressure during brazing or welding, a well-known and superior manufacturing technique.
  • Expectation of Success: A POSITA would have a high expectation of success because combining the known manufacturing technique of flanged sealing (Takahashi) with a basic heat pipe structure (Morikawa) was a straightforward application of conventional engineering principles to improve assembly.

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

• Prior Art Relied Upon: Morikawa, Takahashi, and Nakamura (Japanese Unexamined Utility Model Application Publication No. S50-55262).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground incorporated the combination of Morikawa and Takahashi from Ground 2 and added Nakamura to teach the limitations related to a “depression” in claims 1 and 3. Nakamura discloses a heat pipe with a molded “concavity (9)” formed in a plate, which projects into the vapor chamber and is bonded to the opposing plate to create a mounting point. Petitioner mapped this “concavity” to the claimed “depression.” Nakamura also teaches a “spacer” function and a “wick” structure, addressing other limitations in claim 1.
  • Motivation to Combine: A POSITA would be strongly motivated to incorporate Nakamura’s teachings because Nakamura expressly identifies and solves shortcomings in Morikawa’s design (referencing Morikawa’s filing number). Nakamura states that joining the metal pipe in the prior design (Morikawa) is difficult and can lead to leaks. It proposes its concavity-based structure as a simpler, more robust manufacturing solution for creating an isolated mounting hole. This direct critique and solution provides a clear reason to modify the Morikawa/Takahashi design with Nakamura's depression feature.
  • Expectation of Success: The combination was argued to be predictable, as it involved substituting one known method for creating an isolated mounting path (Morikawa's metal pipe) with another known, improved method (Nakamura's depression) to achieve the same result with better manufacturability.

4. Key Claim Construction Positions

• “Spacer”: Petitioner proposed the construction “structure used to maintain a space or clearance between the plates.” This was argued to be a broader, plain-meaning construction compared to the Patent Owner’s proposed construction, which added functional limitations such as being “apart from the separately claimed depression” and providing “support for a capillary wick.”
• “Hollow Column”: Petitioner proposed “cylindrical structure surrounding a void or cavity.” This construction was central to mapping Morikawa’s “metal pipe” and Nakamura’s “concavity” to the claim term.
• “Vapor Chamber”: Petitioner proposed “enclosed and hermetically sealed void or cavity in which a working fluid is present to be evaporated (or vaporized) and condensed to transport or spread heat.” This construction was argued to align with the technical understanding of the term and was met by the prior art’s disclosure of airtight heat pipe enclosures containing a working fluid.

5. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under 35 U.S.C. § 325(d). It was contended that this petition was not redundant of a previously filed petition (IPR2019-00147) because it relied on a new primary reference, Morikawa, which was not asserted for invalidity in the prior petition. Petitioner asserted that the grounds were substantially different, particularly as Morikawa expressly teaches a “spacer” that meets the “hollow column” limitation, leading to different arguments than those based on the prior petition’s primary reference (Nakamura).

6. Relief Requested

• Petitioner requested the institution of an inter partes review and cancellation of claims 1-3 of the ’680 patent as unpatentable under 35 U.S.C. § 103.