PTAB

IPR2025-01476

BOE Technology Group Co Ltd v. Samsung Display Co Ltd

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petition

1. Case Identification

2. Patent Overview

  • Title: Display Device
  • Brief Description: The ’279 patent discloses a display device, particularly an OLED display, with an integrated touch-sensing unit. The touch unit is formed on the display's encapsulation layer and comprises two primary conductive patterns separated by an insulating layer, arranged to form an underpass-type bridge structure for crossing electrodes.

3. Grounds for Unpatentability

Ground 1: Claims 1, 3, 15, and 18 are obvious over Chen, with or without Hsieh and/or Kobayashi.

  • Prior Art Relied Upon: Chen (Chinese Patent No. CN203759670U), Hsieh (Chinese Application No. CN105320372A), and Kobayashi (Japanese Patent No. JPH0646348B2).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Chen disclosed all elements of independent claim 1 except for the relative thickness of the conductive patterns. Chen teaches a touch panel for OLED displays with two conductive layers separated by an insulator. The upper layer includes first and second touch sensor parts and their corresponding connection parts, while the lower layer forms an underpass-type bridge connection for one set of sensors. This structure directly maps to the arrangement of conductive patterns, sensors, and connection parts recited in claim 1.
    • Motivation to Combine (for §103 grounds): Although Chen suggests the conductive layers may have approximately the same thickness, Petitioner contended that adjusting their relative thickness was an obvious design choice with predictable results. A person of ordinary skill in the art (POSITA) would be motivated to make the upper conductive pattern (containing the main sensor arrays) thicker than the lower pattern (containing the bridge) to mitigate known problems at crossover points. A thicker upper wire over the "step" created by the lower bridge reduces the risk of disconnection and improves mechanical integrity. Kobayashi was cited as expressly teaching that making an upper conductive layer thicker than a lower one at intersections reduces disconnections.
    • Expectation of Success: A POSITA would have a high expectation of success, as modifying layer thickness is a routine fabrication parameter used to solve a well-understood problem (step coverage) in semiconductor and display manufacturing.

Ground 2: Claims 4-14 are obvious over Chen in view of Park, with or without Hsieh and/or Kobayashi.

  • Prior Art Relied Upon: Chen (as above) and Park (Application # 2014/0333855).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed dependent claims reciting specific material compositions and thickness ranges. Petitioner asserted that while Chen teaches using "metal composite layers," it does not specify the exact materials or thicknesses. Park was argued to cure this deficiency by disclosing detailed examples of multi-layer conductive structures for touch sensors, including specific materials like molybdenum-aluminum-molybdenum (Mo-Al-Mo) and titanium-aluminum-titanium (Ti-Al-Ti) stacks. Park also provides specific thickness ranges for each layer that Petitioner argued either overlap with or render obvious the ranges claimed in the ’279 patent.
    • Motivation to Combine: A POSITA implementing Chen's general concept of a composite layer would naturally consult other prior art, such as Park, for established, high-performance material combinations and process parameters. Park's detailed teachings on using multi-layer stacks to optimize adhesion, conductivity, and corrosion resistance provide a clear motivation for its combination with Chen's foundational touch sensor layout. The combination represented applying a known, advantageous material technology (from Park) to a known device structure (from Chen).
    • Expectation of Success: Success would be expected because the combination involved applying known materials using well-understood deposition techniques to achieve predictable improvements in electrode performance, which was a routine optimization within the skill of a POSITA.

Ground 3: Claims 16-17 are obvious over Chen in view of Lee-343, with or without Hsieh and/or Kobayashi.

  • Prior Art Relied Upon: Chen (as above) and Lee-343 (Application # 2012/0105343).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground targeted claims 16-17, which concern the configuration of sensor mesh lines and how connection parts cross them. Petitioner argued that Chen's bridge design involves overlapping connections. Lee-343 specifically addresses the problem of overlapping connections in touch sensors, recognizing they are prone to failure from electrostatic discharge (ESD) and increased capacitance.
    • Motivation to Combine: A POSITA would recognize the potential ESD and performance issues with Chen's overlapping connector design. Lee-343 teaches a solution to this exact problem by using a non-overlapping, dual-bridge connection structure. Petitioner contended that a POSITA would be motivated to modify Chen's design by substituting Lee-343's improved, non-overlapping connectors to yield the predictable result of enhanced reliability and ESD resistance. This was presented as a simple substitution of one known element for another to improve a similar device.
    • Expectation of Success: A POSITA would reasonably expect success because the modification involved applying a known solution (Lee-343's connector design) to address a known problem (ESD susceptibility in crossing conductors) within a conventional touch-sensor architecture.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including grounds where Her (Application # 2015/0049030) served as the primary reference instead of Chen, arguing Her similarly discloses the foundational touch sensor structure on an OLED display. Petitioner also presented a ground asserting that claims 1, 3, and 15 are obvious over Hsieh alone.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-19 of the ’279 patent as unpatentable.