PTAB

IPR2019-00338

Cooler Master Co Ltd v. Aavid Thermalloy LLC

Key Events

Petition

Title: Integrated Circuit Heat Pipe Heat Spreader with Through Mounting Holes
Brief Description: The ’680 patent describes heat pipes, specifically vapor chambers, designed for cooling integrated circuits. The invention focuses on creating through-holes for fasteners that allow the heat pipe to be mounted to components without breaching the hermetically sealed internal vapor chamber.

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 teaches a panel-type heat pipe with through-paths for mounting components, discloses every limitation of claims 5 and 8. Morikawa’s structure was alleged to include top and bottom plates bonded at their periphery (the "edge lip") to form an airtight enclosure (the "vapor chamber") containing a wick and working fluid. Petitioner asserted Morikawa’s "metal pipe" or "metal column," which extends between the plates to form a fastener passageway, directly corresponds to the claimed "hollow column" that is sealed to openings in the top and bottom plates.
- Key Aspects: This ground asserted that a single prior art reference rendered the claims obvious, contending that all claimed features were present in Morikawa's design for creating fastener holes in a heat pipe while maintaining its sealed integrity.

Prior Art Relied Upon: Morikawa and Takahashi (Japanese Examined Utility Model Application Publication No. H8-10205).
Core Argument for this Ground:
- Prior Art Mapping: This ground was presented as an alternative, arguing that if Morikawa’s peripheral seal was not found to meet the "edge lip" limitation, Takahashi supplied this teaching. Takahashi discloses forming a sealed heat pipe container by joining two plate members that have outwardly protruding flanges at their peripheries.
- Motivation to Combine: Petitioner argued a POSITA would combine Takahashi’s flange design with Morikawa’s heat pipe to improve manufacturability. Morikawa’s design, which showed plates joined at a perpendicular boundary, was asserted to be difficult to clamp and bond. Takahashi’s outward-facing flanges provided an easier surface for manufacturing processes like pressing, brazing, or soldering, representing a known and better way to achieve the required airtight seal.
- Expectation of Success: Because the manufacturing processes taught by Takahashi were well-known, a POSITA would have had a high expectation of success in applying them to Morikawa’s analogous heat pipe structure to create a more robust and easily manufactured peripheral seal.

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 added Nakamura to teach an alternative way of forming the "hollow column" structure. While Morikawa taught a separate "metal pipe" inserted between the plates, Nakamura taught forming the column structure by creating opposing "concavities" directly in the top and bottom plates themselves, which are then joined together.
- Motivation to Combine: The motivation to add Nakamura’s teachings was argued to be particularly strong because Nakamura expressly cited Morikawa and described its own invention as a solution to the manufacturing difficulties and disadvantages of Morikawa's design. A POSITA reading Nakamura would therefore be directly motivated to modify Morikawa’s structure with Nakamura’s integrally formed concavity design to create a simpler and more reliable hollow column for fasteners.
Additional Grounds: Petitioner asserted a fourth ground that claims 6 and 7 are obvious over the combination of Morikawa, Takahashi, and Nakamura, further in view of Yamamoto (Patent 6,082,443), to add teachings related to attaching a heat sink with multiple fins.

"Hollow Column": Petitioner argued this term lacked a plain and ordinary meaning in the art at the time of invention and was not defined in the specification. Based on the patent’s figures, Petitioner proposed the construction "cylindrical structure surrounding a void or cavity." This construction was central to mapping prior art structures, like Morikawa's "metal pipe" and Nakamura's joined "concavities," to the claims.
"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 spread heat." This construction was critically distinguished from the Patent Owner's proposal by omitting the requirement that "capillary forces are utilized," arguing that wickless heat pipes were known in the art and the claims did not require a wick.
"Lip": Petitioner proposed the term to mean "portion of the plate comprising a region bonded to another plate." This was contrasted with the Patent Owner's narrower construction requiring the bonded region to be on the plate's "inner or interior surface," which Petitioner argued was physically contradictory, as the bonded region itself forms the outer boundary and is no longer an "inner" surface.

Petitioner argued against discretionary denial under 35 U.S.C. § 325(d) for two primary reasons. First, none of the prior art references relied upon in the petition (Morikawa, Takahashi, Nakamura, Yamamoto) were cited or considered during the original prosecution of the ’680 patent. Second, the petition was substantially different from a previously filed petition (IPR2019-00145) challenging the same claims because this petition relied on a new primary reference, Morikawa, whereas the previous petition relied on Nakamura as the primary reference, leading to different invalidity arguments.

Petitioner requests institution of an inter partes review and cancellation of claims 5-8 of the ’680 patent as unpatentable.