Western Digital Corp v. Kuster Martin

1. Case Identification

• Case #: IPR2020-01410
• Patent #: 8,705,243
• Filed: August 4, 2020
• Petitioner(s): Western Digital Corporation, Western Digital Technologies, Inc., and SanDisk, LLC
• Patent Owner(s): Martin Kuster
• Challenged Claims: 1-18

2. Patent Overview

• Title: External Storage Device with Two-Tier Connector
• Brief Description: The ’243 patent describes an external storage device, such as a USB flash drive, featuring a connector with a two-tier contact arrangement designed to support multiple interfaces (e.g., USB 2.0 and USB 3.0). The invention focuses on the mechanical structure of the connector, which includes a substrate, a memory die stack, a controller, and a "contact bar" comprising a cover, resilient contacts ("springs"), and non-resilient contacts ("connection fingers") at different heights.

3. Grounds for Unpatentability

Ground 1: Anticipation over Hsiao - Claims 1-4, 9-13, and 18 are anticipated by Hsiao under 35 U.S.C. §102.

• Prior Art Relied Upon: Hsiao (Patent 8,480,435).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Hsiao, which teaches a Chip-on-Board (COB) USB flash drive with both USB 2.0 and 3.0 interfaces, discloses every element of the challenged claims. Hsiao’s device includes a substrate (310), a memory (340), and a controller (330). Its connector features a contact bar (main body 320) with resilient USB 3.0 terminals (323, the claimed "springs") and non-resilient USB 2.0 terminals (322, the claimed "connection fingers"). Petitioner argued that Hsiao shows the fingers embedded in the contact bar cover and that the "upwardly bended" portion of the springs is located at a first distance from the substrate, while the fingers are at a second, lesser distance, thus meeting the relative height requirements.
  • Key Aspects: This ground asserted that Hsiao's figures and description provide a complete blueprint for the claimed invention, including the specific two-tier contact arrangement that was the focus of allowance during prosecution.

Ground 2: Obviousness over Hsiao and Sun - Claims 1-18 are obvious over Hsiao in view of Sun under 35 U.S.C. §103.

• Prior Art Relied Upon: Hsiao (Patent 8,480,435) and Sun (WO 2011/160321).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground supplemented Hsiao with Sun to address dependent claims related to memory die stack configurations (claims 4-8 and 13-17). Petitioner argued that while Hsiao discloses the core connector, Sun explicitly teaches various memory arrangements, including stacking multiple dies, mounting stacks on either or both sides of the substrate (PCB), and using overlapping (zigzag) stacking arrangements. Sun discloses these techniques for USB 3.0 compatible flash drives to increase storage capacity and maintain a compact form factor.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Hsiao’s connector design with Sun’s well-known memory stacking and placement techniques to meet predictable design goals. For instance, a POSITA would mount memory on both sides of Hsiao's substrate (as taught by Sun) to increase memory capacity without increasing the device's length, or stack multiple dies to achieve higher density.
  • Expectation of Success: The combination involved applying conventional memory packaging solutions (from Sun) to a standard USB connector structure (from Hsiao), which would have been a routine and predictable process for a POSITA.

Ground 3: Obviousness over Chen and Cheng - Claims 1-6 and 9-15 are obvious over Chen in view of Cheng under §103.

• Prior Art Relied Upon: Chen (Patent 7,625,243) and Cheng (Application # 2009/0098773).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground presented an alternative invalidity theory based on different art. Petitioner argued Chen discloses a USB connector with the same fundamental two-tier contact arrangement claimed in the ’243 patent, including a housing (10, the "contact bar cover"), flat non-elastic contacts (131-134, the "fingers"), and elastic contacts (137, the "springs") that protrude upwardly. Cheng was introduced to teach mounting memory on both surfaces of a flash drive’s PCB to miniaturize the device while increasing memory capacity, addressing dependent claims related to memory placement.
  • Motivation to Combine: A POSITA would have been motivated to incorporate the dual-sided memory mounting taught by Cheng into a device using Chen's connector to achieve the known benefits of increased storage capacity in a smaller physical footprint.
  • Expectation of Success: Combining a known connector layout with a known memory placement strategy was presented as a straightforward application of existing technologies to achieve a predictable result.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Chen, Cheng, and Hiller (for stacked die arrangements) and Chen and Sun, which relied on similar theories of combining known connector structures with conventional memory configurations or adding explicit USB 3.0 compliance as taught by references like Wan.

4. Key Claim Construction Positions

• "Mounted on": Petitioner argued this term should be construed as “Securely Attached, Affixed or Fastened To,” citing Federal Circuit precedent. This construction supports the argument that the contact bar does not need to be mounted entirely on the substrate’s connection surface.
• "Embedded to be exposed upon the cover of the contact bar": Petitioner contended this phrase, added during prosecution, means "set firmly into a mass or material," based on its ordinary dictionary definition. This construction is critical to mapping prior art where contacts are recessed into or held by an insulative housing.
• "Memory die stack": Petitioner asserted that, based on the patent specification, a "stack" can comprise a single memory die. This prevents the Patent Owner from arguing that prior art showing a single die does not meet this limitation.

5. Key Technical Contentions (Beyond Claim Construction)

• Effective Filing Date: Petitioner argued that claims 1-18 are not entitled to the priority date of the provisional applications. The key limitation "a plurality of connection fingers embedded to be exposed upon the cover of the contact bar" was allegedly not disclosed in the provisionals, which only showed contacts formed on the PCB surface. Therefore, the effective filing date is the filing date of the non-provisional application (January 31, 2012), making more publications available as prior art.

6. Arguments Regarding Discretionary Denial

• §325(d) (Same or Substantially Same Art): Petitioner argued against discretionary denial because the Examiner materially erred in evaluating Hsiao. Hsiao was submitted late in prosecution via a Supplemental Information Disclosure Statement (SIDS) after a notice of allowance had already issued, and the Examiner's subsequent supplemental allowance notice gave no substantive analysis or explanation for why the claims were patentable over it. Further, the petition relied heavily on uncited art (Chen, Sun, Cheng, etc.) that was never before the Examiner.
• §314(a) (Fintiv Factors): Petitioner argued the Fintiv factors strongly favor institution. At the time of filing, no trial date was set in the parallel district court litigation, the court had invested minimal time in the merits, and Petitioners planned to seek a stay. Petitioner also argued for minimal overlap between the IPR grounds and the district court case, as different prior art would be used in litigation, and pledged not to pursue the same grounds in court if IPR is instituted.

7. Relief Requested

• Petitioner requests institution of an inter partes review for claims 1-18 and cancellation of all challenged claims as unpatentable.