BOE Technology Group Co Ltd v. Samsung Display Co Ltd

1. Case Identification

• Case #: IPR2025-01557
• Patent #: 7,279,708
• Filed: September 19, 2025
• Petitioner(s): BOE Technology Group Co., Ltd.
• Patent Owner(s): Samsung Display Co., Ltd.
• Challenged Claims: 1-5, 7, 9-15

2. Patent Overview

• Title: Electroluminescence Display Device And Method Of Manufacturing The Same
• Brief Description: The ’708 patent discloses an electroluminescence (EL) display device featuring a "sub-conductive layer" designed to electrically connect a cathode to power supply lines, thereby reducing wiring resistance. The sub-conductive layer includes "penetration portions" to allow gas generated from an underlying organic insulating layer to escape, preventing damage to the display during manufacturing.

3. Grounds for Unpatentability

Ground 1: Claims 1-5, 7, and 9-15 are obvious over Matsueda.

• Prior Art Relied Upon: Matsueda (Application # 2004/0115989).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Matsueda discloses all limitations of the challenged claims. Matsueda teaches an EL display with auxiliary cathode wiring (the claimed “electrode power supply line”) to reduce the resistance of the common cathode. It further discloses "islanded" Indium Tin Oxide (ITO) layers formed on a planarizing film (the claimed "insulating layer") to connect the cathode to the auxiliary wiring. Petitioner asserted these "islanded" ITO layers are the claimed "sub-conductive layer," and the physical separation between the islands inherently creates the claimed "penetration portion," which would allow gas to escape from the underlying planarizing film. For claim 7, Petitioner contended that Matsueda shows the power supply line and the source/drain electrodes of the thin-film transistor (TFT) are formed on the same insulating interlayer film.
  • Motivation to Combine (for §103 grounds): As a single-reference ground, the primary argument was that Matsueda teaches all elements. Petitioner contended it would have been an obvious design choice for a person of ordinary skill in the art (POSITA) to use an organic material for Matsueda’s planarizing film, as this was a common practice for creating smooth surfaces in EL devices at the time.
  • Expectation of Success (for §103 grounds): A POSITA would expect success in using a standard organic planarizing film, a well-known material, in the structure taught by Matsueda.

Ground 2: Claim 7 is obvious over Matsueda in view of Yamazaki.

• Prior Art Relied Upon: Matsueda (Application # 2004/0115989) and Yamazaki (Application # 2003/0194484).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that to the extent Matsueda does not explicitly teach all limitations of claim 7, Yamazaki supplies the missing elements. Specifically, Yamazaki discloses an OLED display where a TFT layer is disposed under the first electrode (anode). It also teaches an electrode power supply line (connection wiring 908) that is comprised of the same layer as the source/drain electrodes of the TFTs.
  • Motivation to Combine (for §103 grounds): A POSITA would combine Matsueda and Yamazaki because both references address the identical technical problem of lowering cathode resistance in OLED displays via auxiliary wiring. A POSITA seeking to implement Matsueda's design would look to references like Yamazaki for specific, well-understood TFT and wiring configurations to integrate into the overall structure.
  • Expectation of Success (for §103 grounds): Because both references disclose similar OLED display structures and address the same technical field, a POSITA would have a reasonable expectation of success in combining their respective teachings without undue experimentation.

Ground 3: Claims 1, 2, 5, 7, 9, 11, 12, and 15 are obvious over Koyama in view of Nakanishi.

• Prior Art Relied Upon: Koyama (Application # 2002/0021266) and Nakanishi (Application # 2002/0153611).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner asserted Koyama discloses an OLED display with a structure meeting most limitations of claim 1, including a connecting wiring (the "sub-conductive layer") formed on an organic interlayer insulating film to connect to a protective electrode. However, Koyama does not explicitly teach a "penetration portion." Nakanishi was introduced to remedy this deficiency. Nakanishi directly addresses the problem of gas release from underlying organic layers during heat treatment in manufacturing, which it solves by forming through-holes (the "penetration portion") in an overlying conductor layer.
  • Motivation to Combine (for §103 grounds): A POSITA implementing Koyama's device, which includes an organic insulating layer, would recognize the known problem of gas blistering during manufacturing heat treatments. Nakanishi provides the solution, describing the use of through-holes as "conventional wisdom." A POSITA would therefore be motivated to incorporate Nakanishi’s known solution into Koyama’s device to improve manufacturing reliability and device performance.
  • Expectation of Success (for §103 grounds): The combination was argued to be predictable because Nakanishi's technique was a known, successful, and conventional method for solving a problem inherent in devices like Koyama's.

• Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 4) against claims 1-5, 7, and 9-15 based on the combination of Matsueda and Nakanishi, arguing that Nakanishi supplies the explicit teaching of penetration portions for gas release if Matsueda's "islanded" structure is deemed insufficient.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not deny institution under Fintiv or §325(d). It was asserted that a Final Written Decision (FWD) would issue before any trial in the corresponding district court litigation, which has not yet been scheduled. Petitioner also contended the petition presents strong merits. Finally, it was argued that the prior art references and arguments are new and were not considered by the examiner during the original prosecution, which was brief and focused only on §112 rejections.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-5, 7, and 9-15 of the ’708 patent as unpatentable.