PTAB

IPR2024-01461

Solus Advanced Materials Co Ltd v. SK nexilis Co Ltd

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Easily Handleable Electrolytic Copper Foil, Electrode Comprising The Same, Secondary Battery Comprising The Same, And Method For Manufacturing The Same
  • Brief Description: The ’689 patent relates to an electrolytic copper foil for secondary batteries purported to have improved handleability and durability. The invention is defined by specific claimed ranges for physical and mechanical properties, including coefficient of thermal expansion (CTE), tensile strength, weight deviation, peak count (Pc), and surface roughness (Rz).

3. Grounds for Unpatentability

Ground 1: Obviousness over Shinozaki, Khatibi, and Toshio (or Kim) - Claims 1-10 are obvious over Shinozaki in view of Khatibi and Toshio (or Kim).

  • Prior Art Relied Upon: Shinozaki (Application # 2013/0108922), Khatibi (a 2006 conference proceeding on copper foil properties), Toshio (Korean Patent Pub. No. 2012/0003485A), and Kim (Application # 2013/0108887).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Shinozaki disclosed the core invention: an electrolytic copper foil for lithium-ion batteries with a matte and shiny surface, specific surface roughness (Rz), tensile strength, and elongation values that meet or render obvious the limitations of claim 1. To meet limitations not explicitly disclosed in Shinozaki, Petitioner asserted that Toshio or Kim taught applying protective layers (e.g., chromate, silane) to both surfaces of such a foil to improve rust prevention and adhesion. For the CTE limitation, Petitioner relied on Khatibi, which provided CTE data for similar electrodeposited copper foils at various temperatures, showing values squarely within the claimed range. For the weight deviation limitation, Petitioner contended Kim taught controlling this property to 3% or less to prevent wrinkles, a goal shared with Shinozaki. The key peak count (Pc) limitation was allegedly rendered obvious by Shinozaki because its disclosed surface roughness parameters (Sm and Ra) could be used to calculate a Pc value falling within the claimed range.
    • Motivation to Combine: A POSITA would combine these references to improve upon Shinozaki’s base foil. Since Shinozaki, Toshio, and Kim all address copper foils for secondary batteries and share goals of enhancing adhesion and preventing defects, a POSITA would be motivated to apply the known protective layers from Toshio or Kim to Shinozaki’s foil. Because Khatibi provided fundamental CTE data for the exact type of material used in Shinozaki, a POSITA would naturally consult it to understand the inherent thermal properties of the foil.
    • Expectation of Success: Success was expected because the combination involved applying conventional techniques (protective layers) to a known material (Shinozaki's foil) to achieve predictable results (improved corrosion resistance and adhesion) without altering the foil's fundamental properties disclosed by Shinozaki and Khatibi.

Ground 2: Obviousness over Kim, Khatibi, and Griesi - Claims 1-10 are obvious over Kim in view of Khatibi and Griesi.

  • Prior Art Relied Upon: Kim (Application # 2013/0108887), Khatibi (a 2006 conference proceeding), and Griesi (a 2014 university publication on copper foil characterization).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Kim served as the primary reference, disclosing an electrolytic copper foil for batteries with matte and shiny surfaces, protective layers, and specific values for tensile strength, weight deviation, and surface roughness (Rz) that met several claim limitations. For the peak count (Pc) limitation, Petitioner turned to Griesi, which described a method for characterizing untreated electrolytic copper foils and explicitly disclosed a measured Pc value of 19.2, falling within the claimed range of 3 to 92. Petitioner argued Griesi's foil was analogous to Kim's. Khatibi was again used to supply the CTE limitation, as its data on the thermal expansion of electrodeposited copper foils was directly relevant to the foil described by Kim.
    • Motivation to Combine: A POSITA starting with Kim’s foil and seeking to optimize its surface to prevent wrinkles and improve uniformity would have been motivated to consult Griesi. Griesi provided detailed surface characterization, including the Pc parameter, which was known to relate to surface uniformity and bonding. Recognizing the similarities between the foils, a POSITA would have found it obvious to optimize Kim’s foil to achieve the beneficial Pc values disclosed in Griesi. A POSITA would also consult Khatibi to understand the inherent CTE of Kim's foil.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in optimizing the Pc of Kim's foil, as it involved routine experimentation with known electrodeposition parameters. The viability of achieving the claimed Pc range was demonstrated by Griesi's explicit disclosure of a value within that range.

4. Key Technical Contentions (Beyond Claim Construction)

  • Peak Count (Pc) Calculation: A central contention of the petition was that the claimed "peak count (Pc)" is a well-recognized surface roughness parameter, equivalent to Rpc, that is not novel. Petitioner argued that even if a reference like Shinozaki did not explicitly state a Pc value, a POSITA could readily calculate or derive it from other disclosed standard roughness parameters, such as the mean spacing of profile elements (Sm). The petition provided a detailed statistical analysis (a Gaussian distribution model) to demonstrate that the Sm and Ra values reported in Shinozaki's examples would necessarily result in a calculated Pc value falling within the claimed range of 3 to 92.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §314(a) and §325(d) would be inappropriate.
  • Fintiv Factors: The petition asserted that the Fintiv factors favored institution. It argued the parallel district court litigation was in its early stages with significant resources yet to be expended on invalidity. Further, Petitioner filed the IPR well before the one-year statutory bar and stipulated that it would not pursue the same invalidity grounds in the district court if the IPR is instituted.
  • Advanced Bionics Test: Petitioner contended that the petition presented new prior art and arguments, such as Griesi and the detailed Pc calculations from Shinozaki's data, which were not considered by the examiner during prosecution of the ’689 patent.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-10 of the ’689 patent as unpatentable under 35 U.S.C. §103.