PTAB

IPR2019-00583

KEMET Electronics Corp v. MEC Resources LLC

Log In
Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Inductors with Minimized EMI Effect and The Method of Manufacturing The Same
  • Brief Description: The ’390 patent discloses inductors and methods for their manufacture. The invention purports to improve upon a conventional inductor (a conducting coil wound around a magnetic core) by compression-molding a magnetic resin layer, containing magnetic powder dispersed in a polymer resin, to embed the coil.

3. Grounds for Unpatentability

Ground 1: Claims 1-4, 7, 9-14, 17, and 19-20 are obvious over Franco in view of Shafer and other references

  • Prior Art Relied Upon: Franco (a 1995 textbook, "Electric Circuits Fundamentals"), Shafer (Patent 6,204,744), Rittner (Patent 6,600,403), Butherus (Patent 3,953,251), Kaneko (Patent 5,010,313), and Ohkawa (EP Publication # EP0265839A2).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Franco taught the basic elements of an inductor recited in independent claims 1 and 11: a magnetic core (e.g., iron or ferrite) and an electrically conducting coil wound around the core. Petitioner contended that Shafer taught the remaining key limitations: compression-molding a magnetic resin layer (comprised of magnetic iron powder dispersed in a polymer resin like polyester) to embed and enclose an inductor coil. For dependent claims, Petitioner asserted that tertiary references taught specific features, such as Rittner's disclosure of tuning inductance by controlling coating thickness.
    • Motivation to Combine: A POSITA would combine Franco and Shafer to improve Franco's basic, exposed-coil inductor with the known benefits taught by Shafer. These benefits included providing physical protection and magnetic shielding, reducing EMI, minimizing air space to increase inductance and decrease device size, and lowering manufacturing costs. The combination was presented as a predictable application of a known technique (Shafer's compression-molding) to a known device (Franco's inductor) to achieve expected results. Adding Rittner was motivated by the desire for precise manufacturing control by setting inductance values for specific applications.
    • Expectation of Success: Petitioner asserted a POSITA would have had a high expectation of success, as the combination involved applying conventional manufacturing methods to standard inductor components to achieve well-understood benefits in the art.

Ground 2: Claims 1-20 are obvious over Amada in view of Shafer and other references

  • Prior Art Relied Upon: Amada (Patent 6,144,280) and the same combination of secondary and tertiary references from Ground 1 (Shafer, Rittner, Butherus, Kaneko, and Ohkawa).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Amada disclosed a chip inductor with all the basic elements of claim 1: a magnetic bobbin (core), a coil wound around the core, and a protective magnetic resin coating (e.g., epoxy with ferrite powder) that embeds the coil. However, Amada did not explicitly describe the method of applying this coating. Petitioner asserted that Shafer supplied this missing element by teaching a well-known system and method for compression-molding such a magnetic resin layer onto an inductor.
    • Motivation to Combine: A POSITA would combine Amada and Shafer because Amada suggested the combination. Amada described a finished product with a uniform, four-sided coating but did not specify the manufacturing process. A POSITA would have been motivated to use Shafer’s well-known compression-molding method as a simple and effective way to achieve the uniform, air-gap-free structure shown in Amada. This would predictably minimize air spaces, which Shafer taught adversely affect inductor operation.
    • Expectation of Success: Petitioner argued success was predictable because the combination involved applying a known, suitable manufacturing process (Shafer's molding) to produce a known inductor structure (Amada's coated inductor), which would predictably yield an operable and improved device.

  • Additional Grounds: Petitioner asserted additional obviousness challenges for specific dependent claims by adding individual tertiary references to the Franco/Shafer and Amada/Shafer combinations. These grounds argued that a POSITA would have been motivated to make simple substitutions or modifications, for example, using a compression-molded magnetic core (as taught by Butherus), adding an external metal sheath for further shielding (as taught by Kaneko), or using a thermoplastic polymer resin instead of a thermosetting one (as taught by Ohkawa).

4. Key Claim Construction Positions

  • "consolidated": Petitioner contended that for the purposes of the IPR, the term "consolidated" in claim 15 required construction. It argued a POSITA would understand this term to mean that the magnetic core and the magnetic resin layer are formed from the same material and combined into a single structure at the same time. This construction was based on a disclosed embodiment in the ’390 patent where the separate magnetic core is eliminated and the coil is embedded directly into a matrix of the magnetic-resin mixture.

5. Relief Requested

  • Petitioner requests institution of an inter partes review of claims 1-20 of the ’390 patent and cancellation of all challenged claims as unpatentable.