BOE Technology Group Co Ltd v. Optronic Sciences LLC

1. Case Identification

• Case #: IPR2024-01133
• Patent #: 9,263,509
• Filed: July 5, 2024
• Petitioner(s): BOE Technology Group Co., LTD.
• Patent Owner(s): Optronic Sciences LLC
• Challenged Claims: 1-13

2. Patent Overview

• Title: Pixel Structure
• Brief Description: The ’509 patent discloses a pixel structure for electroluminescent displays, such as OLEDs, intended to improve luminous uniformity. The purported novelty is the inclusion of a "first auxiliary electrode" electrically connected to the light-emitting device's first electrode layer to reduce total pixel resistance.

3. Grounds for Unpatentability

Ground 1: Anticipation over Weaver - Claims 1-5, 9, 12-13 are anticipated by Weaver under 35 U.S.C. §102.

• Prior Art Relied Upon: Weaver (Application # 2004/0079945).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Weaver, which discloses an OLED pixel structure, teaches every limitation of the challenged claims. Specifically, Petitioner identified Weaver's "bus line 430" as meeting the "first auxiliary electrode" limitation of claim 1. Weaver’s bus line is shown electrically insulated from the active device (transistor 410) by a passivation layer, disposed below the light-emitting device (OLED 400), and electrically connected to the first electrode layer (anode 406) via a contact window (via 428). Petitioner further mapped Weaver's disclosure of insulating layers, contact windows, isolating structures (integrated shadow mask), and top-emission capabilities to the corresponding limitations in dependent claims 2-5, 9, and 12-13.

Ground 2: Obviousness over Weaver and Lee053 - Claims 6-8 are obvious over Weaver in view of Lee053 under 35 U.S.C. §103.

• Prior Art Relied Upon: Weaver (Application # 2004/0079945) and Lee053 (Application # 2012/0162053).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addresses the dependent claims requiring the auxiliary electrode to comprise a bottom and top electrode layer. Petitioner asserted that while Weaver discloses a single-layer auxiliary electrode (bus line 430), Lee053 explicitly teaches a dual-layer auxiliary electrode structure (dummy wiring 120 and second power wiring 135) to reduce wiring resistance in OLED displays. Lee053 also discloses forming the bottom auxiliary layer and the active device gate in the same layer (claim 7) and the top auxiliary layer and the source/drain in the same layer (claim 8) to simplify manufacturing.
  • Motivation to Combine: A POSITA would have understood the common problem of high resistance in OLED pixel structures leading to power loss and non-uniformity. Petitioner argued a POSITA would combine Lee053’s dual-layer electrode solution with Weaver’s pixel structure to gain the known benefit of reduced resistance and the potential for reduced wiring widths, thus improving performance and scalability. Further motivation existed to adopt Lee053's co-layering of electrodes with transistor components to make the manufacturing of Weaver's device more efficient.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success as both references relate to analogous OLED technology, and the proposed modification involved combining known layered structures using standard semiconductor fabrication techniques.

Ground 3: Obviousness over Weaver and Lee149 - Claims 10-11 are obvious over Weaver in view of Lee149 under §103.

• Prior Art Relied Upon: Weaver (Application # 2004/0079945) and Lee149 (Application # 2009/0015149).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground addresses claims requiring a second auxiliary electrode disposed at a side of the light-emitting device. Petitioner contended that Lee149 discloses this exact feature, teaching an "electrode pattern 45" disposed at the side of its light-emitting diode to lower the resistance of the first electrode. Lee149 also teaches that its side auxiliary electrode and the device's second electrode layer can be formed from the same metal layer but electrically insulated from each other by a buffer layer (claim 11).
  • Motivation to Combine: The motivation to combine was driven by the shared goal of reducing sheet resistance. A POSITA, aware of the voltage drop issues in Weaver's device, would look to solutions like that in Lee149 and be motivated to add a second auxiliary electrode at the side of Weaver's OLED for the explicitly stated purpose of lowering resistance. Adopting Lee149’s method of forming the side electrode and cathode in the same deposition step would be motivated by manufacturing efficiency.
  • Expectation of Success: Success would be predictable, as the combination involved adding a known supplemental electrode structure to a standard OLED pixel using well-understood fabrication processes.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Weaver with Song (Application # 2014/0183502) or Bae (Application # 2006/0119259). Petitioner also presented tertiary grounds adding Gupta (Patent 9,088,003) or Han (Application # 2011/0248309) to each primary combination to reinforce the teaching that adding a supplemental electrode to reduce resistance was a well-known solution, should the primary combinations be found insufficient.

4. Key Claim Construction Positions

• "auxiliary electrode" (claims 1-2, 5-6, 10-11, 13): Petitioner proposed two alternative constructions.
  • Broad Construction: "supplemental electrode." This construction relies on the plain meaning of "auxiliary" and is applied to Grounds 1-5.
  • Narrow Construction: "supplemental electrode to reduce the total resistance of the pixel structure." This construction is based on statements in the ’509 patent's specification and is argued as an alternative for all grounds. The narrow construction is crucial for the tertiary grounds involving Gupta or Han, which explicitly teach using supplemental electrodes to reduce resistance.
• "disposed at a side of" (claim 10): Petitioner proposed this phrase means the auxiliary electrode "overlaps in the horizontal direction" with the light-emitting device. This construction is argued to permit some vertical overlap, consistent with the ’509 patent's own embodiments, and is critical for mapping side-electrode prior art like Lee149 and Bae.

5. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under Fintiv, asserting that factors weigh in favor of institution. Key reasons included that no trial date has been set in the parallel district court litigation, this IPR addresses all 13 claims while the litigation complaint asserts only one, and the petition satisfies compelling merits standards. Petitioner also argued that denial under §325(d) is unwarranted because the asserted prior art combinations are not the same as, and not cumulative to, the art considered during prosecution.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-13 of the ’509 patent as unpatentable.