PTAB

IPR2019-00862

Samsung Electronics Co Ltd v. NuCurrent Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Operation of Multi-Layer-Multi-Turn High Efficiency Tunable Inductors
  • Brief Description: The ’948 patent relates to methods for operating a multi-layer inductor for use in electrical circuits. The inductor comprises multiple conductor layers separated by insulator layers and is designed for high-efficiency operation, particularly at radio frequencies.

3. Grounds for Unpatentability

Ground 1: Obviousness over Partovi - Claims 1-4, 10, 15-17, 19, 21, 24-27, 31, and 32 are obvious over Partovi

  • Prior Art Relied Upon: Partovi (Application # 2009/0096413).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Partovi, on its own, disclosed or suggested every limitation of the challenged claims. Partovi’s wireless charger circuit (Fig. 29) was identified as the claimed “electrical circuit,” and its multi-layer Printed Circuit Board (PCB) coil (Fig. 18) was mapped to the claimed inductor structure. Petitioner asserted that Partovi’s separate PCB layers constituted the “first and second conductor,” the space between them inherently included an “insulator,” and the vias connecting them were the claimed “connector.” The method steps of operating the circuit were allegedly met by Partovi’s disclosure of adjusting the charger’s voltage and switching frequency (via an MCU) to control power transfer, which propagates an electrical current and generates a magnetic flux within the inductor. Dependent claims were argued to be obvious as they recited inherent properties of inductors (e.g., generating an electromotive force) or well-known design choices (e.g., using copper).
    • Motivation to Combine (for §103 grounds): Although a single-reference ground, Petitioner argued it would have been obvious for a person of ordinary skill in the art (POSITA) to implement the inductor L1 in Partovi’s charger circuit (Fig. 29) using the multi-layer coil structure from Partovi’s own Fig. 18. The motivation was to achieve the very benefits Partovi described for such coils: higher flux densities and more efficient power transfer in a compact design.
    • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success, as implementing a multi-layer PCB coil in a wireless power circuit was a known technique for improving performance, and Partovi itself provided the necessary teachings for both the circuit and the improved coil structure.

Ground 2: Obviousness over Partovi and Tseng - Claims 6, 7, and 13 are obvious over Partovi in view of Tseng

  • Prior Art Relied Upon: Partovi (Application # 2009/0096413) and Tseng (Patent 9,912,173).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed claims reciting specific dimensional and performance characteristics not explicitly detailed in Partovi. For claims 6 and 7, which require a conductor thickness ranging from 1.25 to 4 times the skin depth, Petitioner argued Tseng taught that to reduce power loss from the skin effect, the metal thickness should be “more than twice of the skin depth.” For claim 13, which requires an inductor quality (Q) factor greater than 5, Tseng was cited for disclosing methods to achieve a high Q value (of about 100) by optimizing the spacing of conductive traces to improve efficiency.
    • Motivation to Combine (for §103 grounds): A POSITA, starting with Partovi’s inductor, would be motivated to improve its efficiency and reduce power loss, a goal explicitly stated in Partovi. Tseng provided known, predictable solutions for achieving this by teaching specific, well-understood design rules for conductor thickness relative to skin depth and for trace spacing to improve the Q factor.
    • Expectation of Success (for §103 grounds): A POSITA would have reasonably expected success in applying Tseng’s teachings, as optimizing conductor thickness and Q factor were common and predictable methods for improving the performance of PCB inductors like the one in Partovi.

Ground 3: Obviousness over Partovi and Chiang - Claims 1-4, 10, 15-21, 24-27, 29, and 31-33 are obvious over Partovi in view of Chiang

  • Prior Art Relied Upon: Partovi (Application # 2009/0096413) and Chiang (Patent 7,248,138).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground primarily focused on claims related to the inductor’s physical construction, particularly connections between conductors. Petitioner argued that to the extent Partovi was not explicit enough, Chiang provided clear teachings. Chiang disclosed multi-layer PCB inductors where conductive layers were explicitly separated by insulating layers and connected by vias. Crucially, for claims requiring parallel connections (e.g., claims 18 and 20), Chiang taught connecting conductor layers “in parallel to decrease the impedance of a particular turn of the winding.” This was mapped to the structure of claim 29, which recites first and second inductor subassemblies connected in series, with each subassembly comprising conductors connected in parallel.
    • Motivation to Combine (for §103 grounds): Partovi acknowledged that simply stacking coils and connecting them in series increases resistance and power loss. A POSITA seeking to overcome this known problem would be motivated to consult a reference like Chiang, which taught the specific solution of connecting layers in parallel to reduce resistance. A POSITA would then combine this technique with a series connection between turns to achieve a balanced design with both higher inductance and lower resistance.
    • Expectation of Success (for §103 grounds): Success would be predictable, as combining these known PCB fabrication techniques—using explicit insulators and parallel connections from Chiang with Partovi’s general multi-layer structure—represented the application of familiar design elements to yield the expected result of a functional, higher-performance inductor.
  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Partovi with Phan (Patent 7,601,919) to teach specific conductor and insulator thicknesses, as well as tertiary combinations of Partovi, Chiang, and either Tseng or Phan.

4. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-4, 6-8, 10, 12-13, 15-21, 24-29, and 31-33 of the ’948 patent as unpatentable.