Viavi Solutions Inc v. MateRioN Corp

1. Case Identification

• Case #: PGR2019-00017
• Patent #: 9,989,684
• Filed: November 12, 2018
• Petitioner(s): VIAVI Solutions Inc.
• Patent Owner(s): Materion Corporation
• Challenged Claims: 1-16

2. Patent Overview

• Title: Near-Infrared Optical Interference Filters
• Brief Description: The ’684 patent relates to near-infrared optical interference filters with purported improvements in transmission. The specification describes adding a controlled amount of nitrogen to amorphous hydrogenated silicon (a-Si:H) layers, but the challenged claims are directed more broadly to filters comprising layers of a-Si:H and dielectric materials with specific refractive indices, without reciting nitrogen.

3. Grounds for Unpatentability

Ground 1: Claims 5 and 12-15 Lack Written Description Support under 35 U.S.C. §112(a)

• Prior Art Relied Upon: N/A
• Core Argument for this Ground: Petitioner argued that the specification only taught achieving the claimed passband range extending down to 750 nm by adding nitrogen to the amorphous hydrogenated silicon (a-Si:H) layers to form a-Si:H,N. However, the challenged claims recite this passband range while depending from claims that only require layers of a-Si:H, without the allegedly essential nitrogen. Petitioner contended that by omitting this key feature, the claims cover subject matter for which the inventor did not demonstrate possession. Furthermore, the specification was argued to only disclose an upper passband range of 1000 nm, not the claimed 1100 nm, further indicating a lack of written description support for the full scope of the claims.

Ground 2: Claims 1-6, 8-14, and 16 are Anticipated by Hendrix under 35 U.S.C. §102(a)(1)

• Prior Art Relied Upon: Hendrix (Application # 2014/0014838).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Hendrix disclosed every element of the independent claims. Hendrix taught an optical interference filter with a primary filter stack on one side of a glass substrate and a multilayer anti-reflective (AR) coating on the opposite side, satisfying the two-sided stack limitation of claim 1. Both the filter stack and the AR coating were disclosed as comprising alternating layers of amorphous hydrogenated silicon and various dielectric materials (e.g., SiO2, Ta2O5, TiO2) with refractive indices falling within the claimed range of 1.9 to 2.7. Petitioner argued Hendrix also disclosed that the filter operates in a passband that at least partially overlaps the 800-1100 nm range claimed in the ’684 patent, thereby anticipating the claims.

Ground 3: Claim 7 is Obvious over Hendrix in view of Tang under 35 U.S.C. §103

• Prior Art Relied Upon: Hendrix (Application # 2014/0014838), Tang (Chinese Patent No. 203786316 U).
• Core Argument for this Ground:
  • Prior Art Mapping: Claim 7 requires the two layer stacks on opposite sides of the substrate to function as a low-pass filter and a high-pass filter, respectively, which together define the filter's passband. While Hendrix disclosed a two-sided bandpass filter, it did not explicitly describe this specific low-pass/high-pass functional arrangement. Tang, however, explicitly taught constructing a bandpass filter by depositing a long-wavelength pass filter (low-pass) and a short-wavelength pass filter (high-pass) on opposite sides of a substrate.
  • Motivation to Combine: A POSITA would combine the references because they addressed the same problem of creating compact, multi-layer optical filters. Tang provided a known and predictable design choice for implementing the general two-sided bandpass filter structure taught by Hendrix.
  • Expectation of Success: A POSITA would have a high expectation of success in configuring the dielectric stacks of Hendrix to function as the low-pass and high-pass filters taught by Tang, as it involved applying well-understood principles of optical filter design to achieve a predictable result.
• Additional Grounds: Petitioner asserted additional grounds, including that claims 5 and 12-15 are not enabled under §112 for the same reasons they lack written description, and that claim 15 is obvious over Hendrix in view of Wang (Chinese Patent No. 203849441 U) to teach a specific adjacent SiO2 layer structure.

4. Key Claim Construction Positions

• "layers of amorphous hydrogenated silicon": Petitioner argued this term should be given its plain meaning, which does not require the inclusion of nitrogen. This construction was central to the §112 arguments, as it created a disconnect between the claims (no nitrogen required) and the specification's explicit teaching that nitrogen is necessary to achieve the claimed performance characteristics.
• "a first layers stack on one side ... and a second layers stack on the opposite side": Citing prosecution history disclaimer, Petitioner argued this requires both stacks to be composed of dielectric materials. This construction allowed Petitioner to map Hendrix's AR coating and filter stack, both of which are dielectric stacks, directly onto this limitation to support its anticipation arguments.
• "passband wavelength range of 750-1100nm inclusive": Petitioner contended that, based on arguments the applicant made during prosecution to overcome prior art, this term must be construed to mean that "only light within this range is allowed to transmit through the device without attenuation." This strict, "perfect filter" definition was then used to argue that the specification failed to describe or enable such a device across its full breadth.

5. Relief Requested

• Petitioner requested institution of post-grant review and cancellation of claims 1-16 of Patent 9,989,684 as unpatentable.