PTAB

IPR2021-00184

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 ’423 patent discloses a method for producing nanoparticles by converting ions from a first and a separate second precursor species into the nanoparticle material. This conversion occurs in the presence of a "molecular cluster compound" (MCC) that is different from the precursors and acts as a seed for nanoparticle growth.

3. Grounds for Unpatentability

Ground 1: Claims 1-3, 10-11, 13, and 22-24 are anticipated under 35 U.S.C. §102 by Banin.

  • Prior Art Relied Upon: Banin (International Publication No. WO 03/097904).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Banin discloses a method of synthesizing rod-shaped semiconductor nanocrystals (e.g., InAs) that meets every limitation of claim 1. Specifically, Banin taught reacting a first precursor (InCl₃) and a second precursor ((TMS)₃As) in the presence of a separate molecular cluster compound (gold clusters, Au₁₀₁(PPh₃)₂₁Cl₅). Banin allegedly taught that these gold clusters act as seeds from which the InAs nanorods grow. Dependent claims were also allegedly met, for example, by Banin’s disclosure of specific molar ratios (claim 3), use of a precipitating reagent (claim 10), use of an inorganic salt precursor (claim 11), and use of capping agents (claims 22-24).
    • Key Aspects: The core of the anticipation argument was that a single embodiment in Banin described synthesizing InAs nanoparticles using two distinct precursors and a separate gold MCC under conditions that permit seeding and growth, directly mapping to the challenged claims.

Ground 2: Claims 1, 10-16, and 21-24 are obvious under 35 U.S.C. §103 over Zaban in view of Ptatschek.

  • Prior Art Relied Upon: Zaban (a 1998 journal article on InP quantum dots) and Ptatschek (a 1998 journal article on semiconductor quantum dot solutions).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Zaban taught synthesizing Zn-doped InP nanoparticles by reacting an In-based precursor and a P-based precursor in the presence of a Zn-based precursor (zinc acetate). Ptatschek taught using a Zn-based MCC ([Zn₁₀O₄(OAc)₁₂]-clusters) as a precursor to create nanoparticles, where the MCCs act as seeds. The combined teachings allegedly disclosed converting first (indium oxalate) and second (P(SiMe₃)₃) precursors into InP nanoparticles in the presence of Ptatschek's Zn-based MCC, which acts as a seed.
    • Motivation to Combine: A POSITA would combine Zaban and Ptatschek by replacing Zaban’s simple zinc acetate precursor with Ptatschek’s Zn-based MCC. The motivation was that using MCCs as seeds was known to enable faster nanoparticle growth at lower temperatures and produce nanoparticles of more uniform size, leading to significant cost savings and improved process efficiencies for large-scale production.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because the prior art documented the successful use of MCCs like Ptatschek’s to seed nanoparticle growth. Furthermore, the zinc sources in both references were similar, suggesting a straightforward substitution.

Ground 3: Claims 1, 4, 11-16, 21, and 25 are obvious under 35 U.S.C. §103 over Lucey in view of Ahrenkiel.

  • Prior Art Relied Upon: Lucey (Patent 7,193,098) and Ahrenkiel (a 2003 journal article on InP quantum rods).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Lucey disclosed reacting a metal-ligand complex (which Petitioner asserted is an MCC) with a single precursor to form nanoparticles. Ahrenkiel disclosed synthesizing InP nanoparticles using a mixture of two different precursors, teaching that this approach optimizes the resulting nanoparticle size and shape, which in turn controls optical properties. The combination allegedly taught reacting Ahrenkiel’s two precursors in the presence of Lucey’s MCC to form InP nanoparticles.
    • Motivation to Combine: A POSITA would combine Lucey and Ahrenkiel by replacing Lucey’s single-precursor method with Ahrenkiel’s dual-precursor approach. The motivation was to improve the synthesis method taught by Lucey by incorporating a technique known to provide better control over nanoparticle dimensions (size and shape), thereby maximizing the optical efficiency of the resulting nanoparticles.
    • Expectation of Success: Success was expected because both references operated in the same technical field (nanoparticle formation) and Ahrenkiel successfully used multiple precursors to synthesize InP nanoparticles similar to those made in Lucey. The combination was a predictable modification to improve a known process.
  • Additional Grounds: Petitioner asserted additional obviousness challenges, including claims 1-6, 10-14, and 21-25 as obvious over Banin alone; claims 7-9 as obvious over Banin in view of Bawendi (for adding process monitoring to control nanoparticle size); and claims 4-9 and 25 as obvious over Zaban/Ptatschek with further combinations of Yu (for low-temperature synthesis) and Bawendi (for process monitoring).

4. Key Claim Construction Positions

  • Petitioner argued that for the purposes of the IPR, no claim terms required explicit construction.
  • However, Petitioner noted a potential ambiguity in the term "molecular cluster compound," pointing out that the ’423 patent defines it as relating to clusters of "metal or nonmetal atoms," while a related patent allegedly limits the same term to "metal atoms." Petitioner contended this issue did not need to be resolved because the prior art relied upon disclosed MCCs with metal atoms.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under Fintiv was inappropriate.
  • The core arguments were that: (1) institution would simplify a co-pending district court case, which Petitioner would move to stay; (2) the district court trial date was uncertain due to the pandemic and court calendar, diminishing its weight; (3) investment in the district court case was minimal as key deadlines had not passed; (4) Petitioner stipulated it would not pursue the same invalidity grounds in district court, eliminating overlap; and (5) the merits of the petition were exceptionally strong, weighing against denial.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-16 and 21-25 of the ’423 patent as unpatentable.