PTAB

IPR2021-00183

Samsung Electronics Co Ltd v. Nanoco Technologies Ltd

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Preparation of Nanoparticle Materials
  • Brief Description: The ’828 patent describes nanoparticles and methods for their preparation. The claimed nanoparticle comprises a core semiconductor material containing ions from Groups 13 and 15 of the periodic table, which is provided on a "molecular cluster compound" (MCC) seed that incorporates ions from Groups 12 and 16.

3. Grounds for Unpatentability

Ground 1: Obviousness over Banin and Herron - Claims 1, 3-6, and 8-14 are obvious over Banin in view of Herron.

  • Prior Art Relied Upon: Banin (WO 03/097904) and Herron (a 1993 article in Science).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Banin disclosed a method for synthesizing Group 13-15 (III-V) semiconductor nanocrystals (InAs nanorods) by using a separate MCC as a seed for growth from precursor materials. While Banin primarily exemplified using a gold (Au) MCC, it explicitly taught that the metal catalyst could be a transition metal such as zinc (Zn) or cadmium (Cd). Herron disclosed a large, well-characterized Group 12-16 semiconductor MCC with the formula Cd₃₂S₁₄(SC₆H₅)₃₆·DMF₄. Petitioner contended that substituting Herron’s Group 12-16 MCC for the Au MCC in Banin’s method would result in the claimed nanoparticle: a Group 13-15 core (InAs) provided on a Group 12-16 MCC (CdS-based). Petitioner further argued Banin taught adding shells (e.g., ZnSe, CdSe) to its InAs core, which met the limitations of dependent claims 8-13.
    • Motivation to Combine: A POSITA would combine Banin and Herron because Banin expressly suggested using Group 12 metals like Zn and Cd as catalysts. Group 12-16 MCCs, like the one in Herron, were well-known, widely used, and less expensive than the Au MCCs disclosed in Banin. Using a pre-formed MCC as a seed was known to provide benefits like faster reactions and better size control, making Herron’s stable, well-characterized MCC an obvious and logical choice for use in Banin’s seeded growth process.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because Banin taught that its Group 13-15 cores were compatible with Group 12 catalysts and could be coated with Group 12-16 shells (e.g., CdSe). The fields of art were identical (nanoparticle synthesis), and the underlying chemical principles for seeded growth were well-established.

Ground 2: Obviousness over Zaban, Farneth, and Yu - Claims 1, 3-6, and 14 are obvious over Zaban in view of Farneth and Yu.

  • Prior Art Relied Upon: Zaban (a 1998 article in Langmuir), Farneth (a 1992 article in Chemistry of Materials), and Yu (a 2001 article in J. Am. Chem. Soc.).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner asserted that Zaban disclosed the synthesis of Group 13-15 quantum dots (InP QDs) from In-based and P-based precursors. This process, however, occurred at high temperatures (270 °C). Farneth disclosed stable Group 12-16 MCCs (Zn- and Cd-based) that maintained their structural integrity during reactions. Yu disclosed the principle of "heterogeneous seeded growth," teaching the use of pre-formed seeds like MCCs to grow nanoparticles from separate precursors at much lower temperatures (room temp to 150 °C), which improved nanoparticle uniformity and process efficiency. Petitioner argued that applying the seeded growth technique of Yu, using the stable MCC of Farneth as the seed for Zaban’s InP nanoparticle synthesis, would render the claimed invention obvious.
    • Motivation to Combine: A POSITA would combine these references to improve the efficiency and quality of the nanoparticle synthesis disclosed in Zaban. Using an MCC as a seed, as taught by Yu and Farneth, was known to allow for faster reactions at lower temperatures, saving production costs and energy. Performing Zaban's reaction at the lower temperatures taught by Yu would accommodate the thermal stability of Farneth's MCC and result in nanoparticles with a more uniform size distribution, a desirable optical characteristic.
    • Expectation of Success: A POSITA would reasonably expect this combination to succeed. The prior art demonstrated the successful use of MCCs for seeded growth of nanoparticles from separate precursors at lower temperatures. The references all occupy the same field of art, and the combination involved applying known principles (seeded growth) to a known synthesis method (Zaban's) to achieve predictable improvements.

  • Additional Grounds: Petitioner asserted that claims 1 and 3 are obvious over Banin in view of Farneth. Petitioner also asserted that claims 8-13, which add limitations for first and second semiconductor shell layers, are obvious over Zaban, Farneth, and Yu in view of Braun (a 2001 article in J. Phys. Chem. A). Braun was cited for its teaching of creating multi-shell nanoparticle structures to enhance quantum confinement and improve optical properties, motivating a POSITA to add shells to the core nanoparticle formed from the primary combination.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §314(a) based on the Fintiv factors was inappropriate. Petitioner asserted that institution would simplify a parallel district court case, which would likely be stayed. The district court trial date was uncertain due to the court’s calendar and the COVID-19 pandemic, while the PTAB timeline was fixed. Petitioner contended it filed the IPR petition promptly and had stipulated not to pursue the same invalidity grounds in district court, mitigating concerns of overlap and inefficiency. Finally, Petitioner argued that the strong merits of the petition weighed heavily against discretionary denial.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 3-6, and 8-14 of the ’828 patent as unpatentable under 35 U.S.C. §103.