BOE Technology Group Co Ltd v. Samsung Display Co Ltd

1. Case Identification

• Case #: IPR2025-01494
• Patent #: 11,081,503
• Filed: August 29, 2025
• Petitioner(s): BOE Technology Group Co., Ltd.
• Patent Owner(s): Samsung Display Co., Ltd.
• Challenged Claims: 1-10

2. Patent Overview

• Title: Electronic Device
• Brief Description: The ’503 patent discloses an electronic device with an integrated circuit (IC) mounted on an array substrate. The technology aims to prevent misalignment between the IC's connection bumps and the substrate's connection pads, which can occur due to substrate expansion or contraction, by using symmetrically inclined, parallelogram-shaped pads and bumps.

3. Grounds for Unpatentability

Ground 1: Obviousness over Wildes - Claims 1-10 are obvious over Wildes

• Prior Art Relied Upon: Wildes (Patent 5,951,304)
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Wildes discloses all limitations of the challenged claims. Wildes teaches a multiple-conductor interconnect system using "fanout arrays" of inclined connection pads to accommodate dimensional variations between two substrates, such as those caused by manufacturing variations. Petitioner asserted that Wildes' substrates (70, 72) and their respective connection pads (82, 84) directly map to the claimed array substrate, IC, pad portion, and bump portion. Wildes' figures, particularly FIGs. 6, 13, and 14, were alleged to show first and second sub-pad/sub-bump units with pads and bumps inclined in different directions symmetrically about a midline, as required by independent claim 1 and its dependent claims.
  • Motivation to Combine (for §103 grounds): As a single-reference ground, the motivation was inherent in Wildes' explicit purpose: to solve the problem of misalignment in electrical connections, including for applications like flat panel (LCD) displays and mounting of IC packages. Petitioner contended it would have been obvious for a person of ordinary skill in the art (POSITA) to apply Wildes' solution to connect an IC to a display's array substrate, a specific application contemplated by Wildes itself.
  • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success because applying Wildes' teachings for their intended purpose—mitigating misalignment—would predictably result in a more reliable electrical connection in a display assembly.

Ground 2: Obviousness over Wildes and Cristaldi - Claims 1-10 are obvious over Wildes in view of Cristaldi

• Prior Art Relied Upon: Wildes (Patent 5,951,304) and Cristaldi (a 2009 textbook titled “Liquid Crystal Display Drivers: Techniques and Circuits”)
• Core Argument for this Ground:
  • Prior Art Mapping: Wildes was asserted to teach the core inventive concept of using inclined, symmetrical pads and bumps to solve misalignment, as detailed in Ground 1. Cristaldi was introduced to supply the context of conventional Chip-on-Glass (COG) technology, where an IC is mounted directly onto a glass array substrate. Cristaldi explicitly teaches that the IC's "bump pattern" must match the "pad pattern" on the glass substrate and that thermal stress during manufacturing can cause deformation and misalignment.
  • Motivation to Combine (for §103 grounds): A POSITA would combine these references to improve the reliability of the well-known COG technology described in Cristaldi. Since Cristaldi identifies the problem of substrate deformation and Wildes provides an elegant solution for misalignment caused by such deformation, the combination was presented as a straightforward application of a known solution to a known problem. Wildes' explicit mention of LCDs as a major application would have further prompted this combination.
  • Expectation of Success (for §103 grounds): Success would be expected, as implementing Wildes' fanout array configuration in a standard COG process would predictably yield the benefit of improved connection reliability without extensive redesign.

Ground 3: Obviousness over Lieshout and Imaoka - Claims 1-10 are obvious over Lieshout in view of Imaoka

• Prior Art Relied Upon: Lieshout (WO 2007/145522) and Imaoka (Patent 6,872,081)

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that both Lieshout and Imaoka are directed at solving the same misalignment problem between an IC and a display substrate. Lieshout discloses using inclined, continuous bond pads on a substrate to counteract misalignment with IC bumps. Imaoka similarly teaches using inclined terminals arranged radially to ensure electrical connection is maintained even if the substrate expands or contracts. Together, they were argued to teach all elements of the claims, including an electronic device, array substrate, and an IC with bumps disposed on a pad portion with inclined, symmetrical sub-units.
  • Motivation to Combine (for §103 grounds): A POSITA would combine the teachings of Lieshout and Imaoka because they address the identical technical problem with similar, complementary solutions. Petitioner asserted a POSITA would adopt the inclined parallelogram bump structures from Imaoka into the system of Lieshout to create a more robust connection with a larger contact area than the circular bumps shown in Lieshout. This combination would improve alignment tolerance and ensure reliable connections in high-resolution displays.
  • Expectation of Success (for §103 grounds): The combination would yield predictable results, as it involves incorporating a known, beneficial bump shape (Imaoka's parallelograms) into a system designed for the same purpose (Lieshout's), leading to improved overlap and connection reliability.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including claims 1-10 over Wildes and Lieshout. Further, Petitioner challenged claim 6 as obvious over combinations including Shioda (Japanese Patent Pub. No. 2003-68795), which teaches making a connection pad area larger than a bump area.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) is inapplicable. The petition asserted that the original examination of the ’503 patent was not robust, as the examiner issued no prior art rejections and only a double-patenting rejection. Key prior art references, including Cristaldi, Lieshout, and Imaoka, were never before the examiner. Although Wildes was cited in an Information Disclosure Statement (IDS), it was submitted after the Notice of Allowance and the examiner never substantively discussed or applied it against the claims, meaning there was no evidence of its consideration. Petitioner contended that the asserted grounds are materially different from the examination and that the examiner erred by overlooking persuasive art.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-10 of Patent 11,081,503 as unpatentable.