CoolIT Systems Inc v. Asetek Danmark AS

1. Case Identification

• Case #: IPR2020-00522
• Patent #: 10,078,355
• Filed: February 7, 2020
• Petitioner(s): CoolIT Systems, Inc.
• Patent Owner(s): Asetek Danmark A/S
• Challenged Claims: 1, 2, 5, 6, 8, 10, 11, and 13

2. Patent Overview

• Title: Liquid-Cooling System for a Computer
• Brief Description: The ’355 patent describes a liquid-cooling system for computer components, such as a CPU. The invention purports to provide a more compact, efficient, and integrated system than prior art by combining the heat exchange interface, liquid reservoir, and pump into a single integrated element.

3. Grounds for Unpatentability

Ground 1: Anticipation and Obviousness over Duan - Claims 1, 2, 6, 10, 11, and 13 are anticipated by or, in the alternative, obvious over Duan.

• Prior Art Relied Upon: Duan (Application # 2006/0185830).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Duan discloses every limitation of the challenged claims. Specifically, Duan’s integrated cooling plate module, which includes a cooling plate, a liquid driving module, an accommodation chamber, and a cap, collectively forms the claimed "reservoir" as a single receptacle for circulating fluid. Petitioner contended that Duan’s "accommodation chamber" serves as the claimed "double-sided chassis," which houses an "impeller stage" (the impeller) on one side and a "coil stage" (the stator) on the opposite side, physically separating the stator from the cooling liquid. Furthermore, Duan was alleged to disclose a thermal exchange chamber with an inner surface defining channels for liquid flow and an outer surface for contacting a CPU, as well as a connection to an external heat radiator.
  • Motivation to Combine (for §103 grounds): As an alternative to anticipation, Petitioner argued that even if Duan’s components are not considered explicitly "integrated" into a single reservoir, a person of ordinary skill in the art (POSITA) would have been motivated to combine them. Duan teaches integrating components to "minimize space" in line with the "compact trend of computer[s]." A POSITA would therefore find it obvious to combine Duan's accommodation chamber, cap, and cooling plate into a single receptacle to achieve the claimed compact reservoir.

Ground 2: Obviousness over Duan in view of Cheon - Claim 5 is obvious over Duan in view of Cheon.

• Prior Art Relied Upon: Duan (Application # 2006/0185830) and Cheon (Patent 5,731,954).
• Core Argument for this Ground:
  • Prior Art Mapping: Claim 5 adds the limitation of "a clip having legs configured to secure the double-sided chassis...to the heat-generating component." Petitioner asserted that while Duan teaches mounting its cooling module in contact with a CPU, it does not specify a securing mechanism. Cheon addresses the same problem of cooling a computer chip and explicitly discloses using a "spring clip" to maintain intimate contact between a heat transfer device and the chip. Petitioner argued that Cheon’s spring clip with legs meets the claim limitation.
  • Motivation to Combine (for §103 grounds): A POSITA, seeking to implement Duan's cooling system, would need a method to secure it to the CPU. Cheon provides a known, conventional solution for this exact purpose. Petitioner contended that combining Cheon's well-known spring clip with Duan's cooling module was an obvious design choice, representing one of a finite number of predictable solutions to ensure the required thermal contact.
  • Expectation of Success (for §103 grounds): A POSITA would have a high expectation of success, as using a clip to mount a heat sink is a simple and common mechanical fastening technique.

Ground 3: Obviousness over Duan in view of Shin - Claim 8 is obvious over Duan in view of Shin.

• Prior Art Relied Upon: Duan (Application # 2006/0185830) and Shin (Japanese Application Publication No. 2002-151638).
• Core Argument for this Ground:
  • Prior Art Mapping: Claim 8 adds "a fan configured to direct air through the heat radiator, the fan being driven by a motor separate from the motor of the pump." Petitioner argued that Duan discloses a radiator that dissipates heat into the surrounding air but does not explicitly include a fan, which would lead to the buildup of stagnant hot air. Shin discloses a cooling structure for electronic components that explicitly teaches using an "air cooling fan" to cool components. The ’355 patent itself admits that fans were typical components in prior art liquid-cooling systems.
  • Motivation to Combine (for §103 grounds): Both Duan and Shin sought to create compact and efficient cooling solutions for computer electronics. A POSITA would recognize that the performance of Duan's radiator would be improved by adding a fan to actively move air, a common and well-understood technique taught by Shin and acknowledged as prior art in the ’355 patent. Driving the fan with a separate motor was argued to be an obvious design choice to allow for independent control of liquid flow and airflow, thereby optimizing performance and acoustics.
  • Expectation of Success (for §103 grounds): The combination would predictably result in improved cooling, as adding a fan to a radiator is a standard method for enhancing heat dissipation.

4. Key Claim Construction Positions

• "reservoir": Petitioner noted the parties stipulated in district court to construe this term as a "single receptacle defining a fluid flow path." This construction was central to Petitioner's argument that the combination of Duan's accommodation chamber, cap, and cooling plate constitutes the claimed reservoir.
• "an inlet ... positioned below a center of the impeller": Petitioner argued this phrase should be construed to mean an opening for fluid entrance near the impeller's axis of rotation, not requiring a specific gravitational orientation (i.e., "below" does not strictly mean vertically underneath). This construction was important for mapping the limitation onto Duan’s device, which may be installed in various orientations (e.g., in a tower computer).

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not exercise its discretion to deny institution under §314(a), providing several reasons:
  • The primary prior art reference, Duan, was not considered during the original prosecution of the ’355 patent.
  • The challenged patent is part of a frequently litigated patent family, and institution would promote judicial efficiency by resolving validity questions.
  • The concurrent district court litigation was in its early stages, with no trial date set, making a PTAB decision timely and efficient.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1, 2, 5, 6, 8, 10, 11, and 13 of the ’355 patent as unpatentable.