PTAB

IPR2025-01476

BOE Technology Group Co., Ltd. v. Samsung Display Co., Ltd.

Log In

1. Case Identification

2. Patent Overview

  • Title: Display Device and Method of Manufacturing the Same
  • Brief Description: The ’279 patent relates to a touch-sensing unit integrated directly onto an Organic Light Emitting Diode (OLED) display panel. The technology employs a first and second conductive pattern separated by an insulating layer, where each conductive pattern comprises a multi-layer structure of different materials designed to optimize electrical conductivity and mechanical durability.

3. Grounds for Unpatentability

Ground 1A: 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 discloses the core structure of claim 1: a touch panel for OLED displays having a first (lower) conductive pattern and a second (upper) conductive pattern separated by an insulating layer. Chen’s upper layer includes first and second touch sensor parts and their connecting parts, while the lower layer forms an underpass-type bridge to connect other touch sensor parts, thereby teaching the claimed arrangement of conductive patterns.
    • Motivation to Combine: Petitioner contended that claim 1’s limitation requiring the second (upper) conductive pattern to be thicker than the first (lower) pattern, while not explicit in Chen, was an obvious design choice. A person of ordinary skill in the art (POSITA) would combine Chen's design with teachings from Hsieh, which explicitly states that relative layer thickness is a design choice, or Kobayashi, which teaches making an upper wire thicker than a lower wire at intersections to reduce the risk of disconnection caused by the "step" from the underlying layer.
    • Expectation of Success: A POSITA would have a high expectation of success in making the upper layer thicker, as this was a known solution to the well-understood problem of maintaining electrical integrity over topographical steps in multi-layered electronic devices.

Ground 1B: Claims 4-14 are obvious over Chen and Park.

  • Prior Art Relied Upon: Chen (Chinese Patent No. CN203759670U) and Park (Application # 2014/0333855).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed dependent claims requiring specific thickness ranges and multi-layer material compositions (e.g., Titanium/Aluminum/Titanium). Petitioner asserted that while Chen discloses using "metal composite layers," it leaves the specific materials and thicknesses as open design choices. Park was argued to supply these missing details, teaching multi-layer touch electrodes with a base layer for adhesion, a middle layer for low resistance, and a top layer for corrosion protection. Park provided specific material examples and thickness ranges that overlap with or render obvious those in the challenged claims.
    • Motivation to Combine: A POSITA implementing Chen's touch sensor design would combine it with prior art like Park to find established material stacks and thicknesses that optimize performance. The combination would involve selecting from known options taught by Park for the express purpose of improving adhesion, conductivity, and durability, which amounts to routine optimization.
    • Expectation of Success: Success was predictable because the modifications involved applying known material compositions and deposition thicknesses, which were well within the skill of a POSITA.

Ground 1C: Claims 16-17 are obvious over Chen and Lee-343.

  • Prior Art Relied Upon: Chen (Chinese Patent No. CN203759670U) and Lee-343 (Application # 2012/0105343).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground targeted claims related to the specific arrangement of connections between mesh-like touch sensor parts. Petitioner argued that Chen's design includes connections that overlap, a configuration that Lee-343 teaches is prone to problems from static electricity and higher capacitance. Lee-343 explicitly discloses an improved design using a pair of non-overlapping, underpass-type bridges to solve this known issue.
    • Motivation to Combine: A POSITA would recognize the known shortcomings of the overlapping connector design in Chen and would be motivated to incorporate the solution taught by Lee-343. This modification represented a simple substitution of a known, problematic element (overlapping connectors) with a known, improved element (non-overlapping connectors) to achieve predictable results.
    • Expectation of Success: The combination was expected to be successful because it involved applying Lee-343's improved connector layout to Chen's similar underpass-bridge architecture, a straightforward modification for a POSITA.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including grounds where Her (Application # 2015/0049030) served as the primary reference instead of Chen, combined with Park and Lee-343 for the same respective reasons. A final ground alleged claims 1-3 and 15 are obvious over Hsieh alone.

4. Key Technical Contentions (Beyond Claim Construction)

  • Step-Induced Defects: A central technical argument was that forming a conductive trace (e.g., the second conductive pattern) over a pre-existing trace (the first conductive pattern) creates a topographical "step." This step was argued to be a known cause of defects in the upper trace, including thinning, increased resistance, or complete disconnection. This known problem provided a strong motivation for a POSITA to either make the lower trace thinner or the upper trace thicker, as taught in references like Kobayashi.
  • Material Selection Trade-offs: Petitioner argued that selecting materials and thicknesses for conductive layers in a touch panel was a matter of optimizing known trade-offs. A POSITA would balance factors such as electrical resistivity (thicker, more conductive metals improve performance), mechanical strength (important for flexible displays), and optical properties (opaque metal lines must be thin to avoid blocking light from the underlying display). These predictable design considerations motivated the combination of Chen's structure with Park's specific material stacks and thicknesses.

5. Relief Requested

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