PTAB

IPR2015-00101

AVX Corp v. Greatbatch Ltd

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1. Case Identification

2. Patent Overview

  • Title: Filtered Feedthrough Assembly with Discoidal Capacitor Having an Improved Ground Connection
  • Brief Description: The ’222 patent discloses a filtered feedthrough assembly for an implantable medical device, such as a pacemaker. The invention centers on a method for grounding a discoidal capacitor to the device’s ferrule using a conductive filled polymer, which Petitioner argued was intended to improve reliability and simplify manufacturing compared to traditional soldering or brazing.

3. Grounds for Unpatentability

Ground 1: Obviousness over Evans I in view of Evans II - Claims 1-27

  • Prior Art Relied Upon: Evans I (Patent 5,369,547) and Evans II (Patent 6,094,339).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Evans I taught every limitation of independent claim 1 except for the use of a "conductive filled polymer" for the ground connection. Evans I discloses a nearly identical filtered feedthrough assembly for an implantable medical device, including a ferrule, a terminal pin, an insulator, and a discoidal capacitor. However, Evans I teaches connecting the capacitor’s ground metallization to the ferrule using solder or a conductive glass frit. Petitioner asserted that Evans II, from the same inventor and in the same field, explicitly remedies this difference by teaching the use of conductive filled polymers (e.g., silver-filled polyimide) as a direct and advantageous substitute for solder in creating electrical connections for electronic components. Dependent claims were argued to be obvious as they recited conventional features also found in the prior art, such as specific material compositions or geometric arrangements.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Evans I and Evans II to improve the manufacturing process and reliability of the feedthrough assembly. Evans I’s use of high-temperature solder or glass frit was known to pose risks of thermal damage to components. Evans II directly addresses this by disclosing conductive polymers as a low-temperature, reliable alternative for creating electrical connections. The shared inventor and subject matter would have strongly prompted a POSITA to apply the improved connection method of Evans II to the assembly of Evans I.
    • Expectation of Success: A POSITA would have a high expectation of success. The substitution of one conductive material (solder) for another (conductive polymer) to form an electrical ground connection was a simple, well-established practice in the art. Evans II confirms the suitability of conductive polymers for this exact purpose, ensuring the combination would have yielded a predictable and functional result.

Ground 2: Obviousness over Evans I in view of Ross - Claims 1-27

  • Prior Art Relied Upon: Evans I (Patent 5,369,547) and Ross (Patent 4,110,817).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner again relied on Evans I to teach the fundamental filtered feedthrough structure. The missing element—a conductive filled polymer ground connection—was argued to be taught by Ross. Ross discloses a filtered electrical connector that uses a conductive epoxy (a type of conductive filled polymer) to electrically connect the ground electrode of a discoidal capacitor to the connector’s metal shell. Petitioner contended that the conductive epoxy ground path in Ross is functionally and structurally identical to the "conductive filled polymer" connection claimed in the ’222 patent.
    • Motivation to Combine: The motivation was presented as a straightforward substitution of a known alternative to achieve known benefits. A POSITA designing the device in Evans I would have been aware of different methods for creating ground connections. Ross teaches that using conductive epoxy is an effective method for grounding a discoidal capacitor in a similar filtered assembly. Therefore, a POSITA would be motivated to replace the solder in Evans I with the conductive epoxy taught by Ross to simplify the manufacturing process and improve the device’s mechanical resilience.

Ground 3: Obviousness over Evans I in view of Burger - Claims 1-27

  • Prior Art Relied Upon: Evans I (Patent 5,369,547) and Burger (Patent 3,138,746).

  • Core Argument for this Ground:

    • Prior Art Mapping: As in the previous grounds, Evans I provided the foundational feedthrough assembly. Burger was cited for its teaching of using conductive adhesive compositions to create electrical connections for capacitor components. Specifically, Burger discloses using a conductive adhesive, such as silver flakes in an epoxy resin, to connect capacitor electrodes to terminals. Petitioner argued this is the same as the "conductive filled polymer" recited in the claims.
    • Motivation to Combine: Petitioner argued a POSITA would be motivated to combine these references to solve a known problem. The high temperatures required for soldering in Evans I could damage sensitive components. Burger offers a well-understood, low-temperature alternative with its conductive adhesive. A POSITA would have recognized the interchangeability of these connection methods and would have been motivated to apply Burger’s conductive adhesive to the Evans I assembly to achieve the predictable benefits of a simpler, lower-temperature manufacturing process.

  • Additional Grounds: Petitioner asserted additional obviousness challenges against claims 1-27 based on the combination of Evans I with Bernard (Patent 4,692,224), Hildegard (Patent 3,580,845), or Alwitt (Patent 3,346,782), each of which was argued to disclose the use of conductive polymer-like materials for forming electrical connections in capacitors, providing further motivation for a POSITA to modify the Evans I device.

4. Relief Requested

  • Petitioner requests the institution of an inter partes review and the cancellation of claims 1-27 of Patent 6,219,222 as unpatentable.