AVX Corp v. Greatbatch Ltd

1. Case Identification

• Case #: IPR2014-01461
• Patent #: 7,244,279
• Filed: September 8, 2014
• Petitioner(s): AVX Corporation
• Patent Owner(s): Greatbatch, Ltd.
• Challenged Claims: 1-20

2. Patent Overview

• Title: Use of Poly(alkylene) Carbonates in the Manufacture of Valve Metal Anodes for Electrolytic Capacitors
• Brief Description: The ’279 patent relates to methods for manufacturing electrodes for capacitors. The core inventive concept is a method of forming a pressed valve metal anode by mixing a powdered metal, such as tantalum, with a specific poly(alkylene carbonate) binder before pressing and sintering the mixture.

3. Grounds for Unpatentability

Ground 1: Anticipation/Obviousness over Hahn - Claims 1-2, 4-5, and 7-8 are anticipated by, or in the alternative obvious over, Hahn

• Prior Art Relied Upon: Hahn (Patent 6,224,990).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Hahn disclosed every element of independent claim 1. Hahn teaches a method for forming a capacitor anode by mixing a valve metal powder (tantalum) with a polypropylene carbonate binder, pressing the mixture into a pellet, and then vacuum sintering the pellet. Petitioner asserted that Hahn’s polypropylene carbonate binder meets the general formula recited in claim 1 and that Hahn explicitly references the same commercial grade binder (“Q-PAC”) as the ’279 patent. The heating and sintering step in Hahn inherently decomposes the binder, meeting the final limitation.
  • Key Aspects: The core of this ground is that Hahn allegedly discloses the exact same process using the same type of binder for the same purpose, rendering the claims anticipated under 35 U.S.C. §102.

Ground 2: Obviousness over Lauf in view of Hahn - Claims 1-8 are obvious over Lauf in view of Hahn

• Prior Art Relied Upon: Lauf (Patent 5,184,286), Hahn (Patent 6,224,990).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Lauf disclosed a conventional method for making a tantalum anode that included all steps of independent claim 1 except for the specific use of a poly(alkylene carbonate) binder. Lauf teaches pressing tantalum powder, optionally mixed with small amounts of organic binders, and then sintering the body under a vacuum.
  • Motivation to Combine: Petitioner argued that Hahn expressly taught the use of a polypropylene carbonate binder to solve problems with conventional binders by lowering the amount of residual carbon and minimizing tantalum carbide flaws in the final anode. A POSITA would combine Hahn’s improved binder with the well-known anode manufacturing process of Lauf to achieve the predictable result of a higher-quality anode.
  • Expectation of Success: The substitution of one known organic binder for another improved binder in a standard process would have presented a high expectation of success.

Ground 3: Obviousness over Popp in view of Hahn, Pierret, and/or Lauf - Claims 11-13 and 18-20 are obvious over Popp in view of Hahn, Pierret, and/or Lauf

• Prior Art Relied Upon: Popp (Patent 5,822,177), Hahn (Patent 6,224,990), Pierret (Patent 3,934,179), and Lauf (Patent 5,184,286).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground targets claims directed to a complete electrolytic capacitor, including independent claim 18. Petitioner asserted that Popp disclosed a method of making a tantalum electrolytic capacitor that met all limitations of claim 18 except for the use of a poly(ethylene carbonate) or poly(propylene carbonate) binder; Popp instead used a conventional organic binder like camphor. Popp disclosed the anode, cathode, separator, casing, and electrolyte as claimed.
  • Motivation to Combine: The motivation is identical to the previous ground: a POSITA would have been motivated to replace Popp's conventional binder with Hahn's superior polypropylene carbonate binder to obtain the known and predictable benefits of reduced carbon contamination and improved anode performance. Pierret and Lauf were cited to show that other dependent claim features, such as forming tantalum via beam melt or sodium reduction processes (claim 13), were common and conventional techniques in the art, making their inclusion an obvious design choice.
  • Expectation of Success: A POSITA would have had a high expectation of success in incorporating Hahn's improved binder into the established capacitor manufacturing process disclosed by Popp to achieve a better final product.

• Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations including Pierret as the primary reference in view of Hahn, as well as anticipation and obviousness grounds based on Evans (Patent 5,369,547) alone or in combination with Hahn, Pierret, and/or Lauf.

4. Key Claim Construction Positions

• "Flowable Powder" (Claims 1, 9, 18): Petitioner proposed this term should be interpreted to mean a powder mixed with a binder. This construction was argued to be consistent with the specification, which states that the binder helps the powder “flow” before pressing.
• "Substantially Decompose" (Claims 1, 9, 18): Petitioner proposed this term should mean the combustion of the binder at temperatures exceeding its specific decomposition temperature. This was based on specification language stating the final heating temperature must exceed the binder's decomposition temperature to ensure complete combustion.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-20 of the ’279 patent as unpatentable.