PTAB

IPR2015-01504

CeramTec GmbH v. CeraMedic LLC

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Petition
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1. Case Identification

2. Patent Overview

  • Title: Sintered Al₂O₃ Material, Process for its Production and Use of the Material
  • Brief Description: The ’584 patent is directed to sintered alumina (Al₂O₃) ceramic materials having specific physical and mechanical properties. The claims recite ranges for density, average grain size, hardness, flexural strength, and a non-standard metric termed "dimensionless defect density" (DDD).

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 14 and 26 under 35 U.S.C. §102 over Burger

  • Prior Art Relied Upon: Burger (International Publication No. WO 92/02470).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Burger, specifically its "Example 12," discloses a sintered ceramic material that meets every limitation of claims 14 and 26. Petitioner asserted that Burger expressly teaches the claimed density, mean grain size, and flexural strength. The remaining limitations—Vickers hardness at a specific test load and DDD—were argued to be inherently disclosed. To prove inherency, Petitioner's scientists reproduced the material from Burger's Example 12 and measured its properties. The resulting "Example 12 Reproduction" exhibited a Vickers hardness of 1858 at a 10 N test load and a DDD of 0.18x10⁻³, both falling within the claimed ranges.
    • Key Aspects: The core of this ground rested on experimental evidence from reproducing the prior art to demonstrate that the claimed properties, though not explicitly disclosed in the reference, were necessarily present in the material it described.

Ground 2: Obviousness of Claims 14 and 26-29 under 35 U.S.C. §103 over Burger

  • Prior Art Relied Upon: Burger (WO 92/02470).
  • Core Argument for this Ground:
    • Prior Art Mapping: As an alternative to inherency, Petitioner argued that even if Burger does not inherently disclose the claimed hardness and DDD values, achieving these properties would have been obvious. Burger expressly disclosed materials with high hardness and strength, aligning with the objectives of the ’584 patent. The claimed hardness (≥1750 at 10-100 N) and DDD (<30x10⁻³) were presented as missing limitations.
    • Motivation to Combine: The motivation was rooted in routine optimization. Petitioner contended that hardness and defect structure (quantified by DDD) were well-known result-effective variables in the ceramic arts. A person of ordinary skill in the art (POSITA), starting with Burger's teachings and seeking to improve material strength, would have been motivated to optimize these known variables. Burger itself identified applications like cutting tools where high hardness is critical, providing clear motivation to achieve superior hardness values.
    • Expectation of Success: A POSITA would have had a high expectation of success. The fact that Petitioner’s own reproduction of Burger’s Example 12 readily achieved the claimed properties demonstrated that doing so required only the application of routine, known techniques. For dependent claims 27-29, which recite progressively lower DDD values, Petitioner argued these were also achievable through routine optimization of defect structure.

Ground 3: Obviousness of Claims 14 and 26-29 under §103 over Burger, Yeh & Sacks II, and Lange 1982

  • Prior Art Relied Upon: Burger (WO 92/02470), Yeh & Sacks II (a 1988 journal article), and Lange 1982 (a 1982 journal article).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground augmented the teachings of Burger with two additional references to demonstrate the obviousness of achieving the claimed hardness and DDD. Burger provided the foundational ceramic composition with high density and flexural strength. Lange 1982 and Yeh & Sacks II provided the teachings to optimize hardness and defect density, respectively.
    • Motivation to Combine: A POSITA seeking to improve upon the ceramic materials in Burger would combine these teachings to enhance known performance characteristics. Lange 1982 taught about transformation toughening in similar Al₂O₃-ZrO₂ materials and provided data on hardness at different test loads, guiding a POSITA in optimizing for hardness. Yeh & Sacks II disclosed methods for producing sintered alumina with a nearly defect-free microstructure (i.e., a DDD approaching zero), teaching a POSITA how to minimize defects to improve strength. A POSITA would combine these known techniques to achieve the superior material properties described in the ’584 patent.
    • Expectation of Success: Lange 1982's data showed hardness increases as the test load decreases, giving a POSITA a reasonable expectation that reducing the test load on a material like Burger's would yield hardness values within the claimed range. The defect-free material shown in Yeh & Sacks II demonstrated that achieving extremely low DDD values was well within the capabilities of a POSITA.

4. Key Claim Construction Positions

  • "sintered Al₂O₃ material" (claims 26-29) and "sintered material" (claim 14): Petitioner argued this should be construed to mean a material where Al₂O₃ is a primary component, without requiring a specific minimum amount (e.g., >95%). This construction was critical because Burger's Example 12 is only ~74% Al₂O₃. Petitioner supported this by noting the patentee eliminated a 95% Al₂O₃ limitation during prosecution.
  • "at a test load from 10 to 100 N" (claims 14, 26-29): Petitioner proposed this means the required hardness must be met at any single test load within the specified range, not necessarily at every point throughout the range. This allows a single measurement, like the one taken on the Example 12 Reproduction at 10 N, to satisfy the limitation.
  • "a flexural strength of 800 MPa or greater" (claims 14, 26-29): Petitioner argued this could be measured by either a three-point or four-point bend test. This was important because Burger's Example 12 met the 800 MPa threshold using a three-point test (897 MPa) but not a four-point test (575 MPa).

5. Key Technical Contentions

  • Reproduction of Prior Art Example: The central technical contention was that the material from Burger's Example 12 was successfully reproduced in a laboratory setting. Petitioner argued the chemical composition and physical properties of the reproduced material matched those reported in Burger within an expected range of experimental variation. The measured hardness and DDD of this reproduced material were then used as direct evidence of the inherent properties of the material disclosed in the Burger reference itself.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 14 and 26-29 of the ’584 patent as unpatentable.