PTAB

IPR2018-00965

Nichia Corp v. Document Security Systems Inc

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Semiconductor Device with a Light Emitting Semiconductor Die
  • Brief Description: The ’787 patent describes a semiconductor packaging device for a light-emitting diode (LED) designed for high-density applications. The invention features an LED die with both its anode and cathode contacts located on its bottom major surface, which is then mounted onto a substrate package with interconnects running through vias or along its sidewalls.

3. Grounds for Unpatentability

Ground 1: Obviousness over Lumbard in view of Weeks, Wirth, or Negley - Claims 1-14

  • Prior Art Relied Upon: Lumbard (Patent Re. 36,614), Weeks (Patent 6,611,002), Wirth (International Publication No. WO 2005/081319), and Negley (Application # 2004/0217360).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Lumbard taught a modular, surface-mountable package for an LED on a planar substrate with interconnects formed in plated grooves on the sidewalls, thus disclosing the claimed package structure. However, Lumbard’s package used a conventional wire-bonded LED. Petitioner asserted that Weeks, Wirth, and Negley each disclosed an improved “flip-chip” style LED with both anode and cathode contacts on the bottom surface, as required by the claims. The combination of Lumbard’s packaging substrate with any of these advanced LEDs would satisfy all limitations of the challenged claims.
    • Motivation to Combine: A POSITA would combine Lumbard's low-cost, mass-producible package with the improved flip-chip LEDs from Weeks, Wirth, or Negley. This combination was motivated by the well-known advantages of flip-chip technology, such as creating smaller components, improving reliability by eliminating bond wires (which can obscure light and are a failure point), and enhancing thermal dissipation.
    • Expectation of Success: The combination was a simple substitution of one known element (a wire-bonded LED) for another known element (a flip-chip LED) to obtain predictable results. Petitioner highlighted that the patent's applicants had admitted during prosecution that the semiconductor arts were a well-established and predictable field, reinforcing the high expectation of success.

Ground 2: Obviousness over Ishidu in view of Weeks, Wirth, or Negley - Claims 1, 5, 6, and 7

  • Prior Art Relied Upon: Ishidu (Application # 2006/0198162), Weeks (Patent 6,611,002), Wirth (WO 2005/081319), and Negley (Application # 2004/0217360).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Ishidu disclosed a light-emitting element mounting member (a substrate package) with through-hole vias for interconnection and a flip-chip LED mounted thereon, satisfying most claim limitations. Petitioner argued that the primary feature not explicitly disclosed by Ishidu was that the bottom major surface of the LED die is also the bottom surface of the die's own substrate. This specific feature, however, was explicitly taught by each of Weeks, Wirth, and Negley.
    • Motivation to Combine: A POSITA would be motivated to use one of the LEDs from Weeks, Wirth, or Negley in Ishidu's high-thermal-conductivity package. The motivation was to achieve the benefits described in the secondary references (e.g., smaller device dimensions, elimination of bond wires) within a package known for its superior thermal performance and ease of processing.
    • Expectation of Success: Success was expected because it involved the routine substitution of one flip-chip LED for another to achieve predictable improvements in a well-understood and predictable technical field.

Ground 3: Obviousness over Ogawa in view of Weeks, Wirth, or Negley - Claims 1-14

  • Prior Art Relied Upon: Ogawa (Application # 2006/0113906), Weeks (Patent 6,611,002), Wirth (WO 2005/081319), and Negley (Application # 2004/0217360).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Ogawa taught a light-emitting device comprising a flip-chip LED mounted on a substrate with C-shaped sidewall interconnects. As with the Ishidu ground, Petitioner asserted that Ogawa did not explicitly disclose that the LED's bottom contact surface is also the bottom surface of a substrate integral to the die itself. This limitation, Petitioner contended, was supplied by each of Weeks, Wirth, and Negley.
    • Motivation to Combine: A POSITA would combine the LEDs from the secondary references with Ogawa's package, which was promoted for its excellent heat resistance, light stability, and suitability for simplified mass production. The combination would yield a more robust and compact device by leveraging the known advantages of the secondary references' LED structures.
    • Expectation of Success: The combination represented a straightforward substitution of compatible components, for which a POSITA would have had a reasonable expectation of success.

4. Key Claim Construction Positions

  • "[top] major light emitting surface": Petitioner proposed this term be construed as "of the two largest faces of the LED, the face through which light is emitted."
  • "an oppositely-disposed [bottom] major surface": Petitioner proposed this term means "of the two largest faces of the LED, the face opposite the light emitting face."
  • "the [bottom] major surface ... is a bottom surface of a substrate of the die": Petitioner proposed this phrase means "the face of the LED opposite the light emitting face is on the substrate side of the LED."
  • These constructions were presented to clarify the distinction between the substrate integral to the LED die itself and the separate "substrate packaging assembly" on which the entire die is mounted, a distinction critical to Petitioner's prior art analysis.

5. Key Technical Contentions

  • Effective Filing Date: Petitioner argued that the ’787 patent was not entitled to the filing date of its parent application (the ’605 application). The basis for this contention was that the parent application allegedly failed to provide adequate written description support for the key claimed feature: an LED with both an anode and a cathode located on the bottom major surface of the die's substrate. Therefore, Petitioner contended the patent's effective priority date is its actual filing date of August 14, 2007, which brings additional prior art into scope.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-14 of the ’787 patent as unpatentable under 35 U.S.C. §103.