PTAB

IPR2018-01485

Everlight Electronics Co Ltd v. Bridgelux Inc

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Petition
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1. Case Identification

2. Patent Overview

  • Title: Efficient LED Array
  • Brief Description: The ’929 patent relates to a method for forming a light-emitting diode (LED) apparatus by mounting a plurality of LED chips directly onto a reflective metal substrate. This configuration is intended to provide separate thermal and electrical paths, improving heat dissipation and increasing light output.

3. Grounds for Unpatentability

Ground 1: Anticipation - Claims 1-10 are anticipated by Sanpei

  • Prior Art Relied Upon: Sanpei (EP Patent Publication No. 1 895 602).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Sanpei discloses every limitation of the challenged claims. Sanpei teaches an LED illumination apparatus comprising multiple Gallium Nitride (GaN) LED chips mounted on a metal substrate (e.g., aluminum or copper) configured with a reflective surface of silver plating. The LEDs are bonded directly to this reflective surface to create a vertical thermal path for heat dissipation, while a separate horizontal electrical path is formed by wire bonds connecting the chips' upper contacts. Sanpei explicitly teaches spacing the LEDs apart at intervals to allow light to reflect from the exposed portions of the reflective surface, which has a disclosed reflectivity exceeding 70%.
    • Key Aspects: Petitioner contended that Sanpei’s disclosure is a blueprint for the method claimed in the ’929 patent, teaching the same configuration for the same purpose of improving thermal and optical performance.

Ground 2: Anticipation - Claims 1 and 3-10 are anticipated by Baek

  • Prior Art Relied Upon: Baek (Application # 2007/0075325).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Baek discloses a high-power LED package that anticipates the challenged claims. Baek teaches an array of GaN LED chips surface-mounted directly onto a metal substrate (e.g., copper) having a reflective layer, which may be formed of silver plating. This direct mounting is for "excellent heat dissipating characteristics." The LED chips are spaced apart within recesses on the substrate, which prevents optical interference and allows emitted light to reflect off the surface between the chips, thereby increasing light efficiency. The chips have top-side contacts for wire bonding, creating an electrical path separate from the thermal path into the substrate.
    • Key Aspects: Baek's express purpose was to overcome the poor heat dissipation of conventional LED packages by mounting chips directly to a metal substrate, mirroring the alleged invention of the ’929 patent.

Ground 3: Obviousness - Claims 1-10 are obvious over Ostler in view of Sanpei

  • Prior Art Relied Upon: Ostler (Patent 6,954,270) and Sanpei (EP Patent Publication No. 1 895 602).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that, to the extent Ostler does not anticipate all claims, the combination with Sanpei renders them obvious. Ostler teaches the core concept of an LED array with GaN chips mounted directly on a metal heat sink (e.g., aluminum, silver) to improve thermal performance, with the chips spaced apart. Sanpei teaches a metal substrate with a dedicated reflective surface (e.g., silver plating) specifically adapted to be an interface between LED chips and a heat sink to improve both light reflection and heat dissipation.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references, as they are analogous art addressing the identical problem of creating bright, thermally efficient LED arrays. A POSITA would use Sanpei’s specialized reflective substrate as an interface on Ostler’s heat sink to predictably achieve the well-known benefits of enhanced light output and heat dissipation, which were express goals of both references.
    • Expectation of Success: The combination involved applying known mounting and plating techniques to known components to achieve predictable improvements in reflectivity and thermal management. A POSITA would have reasonably expected success in integrating Sanpei’s reflective substrate into Ostler’s design.

  • Additional Grounds: Petitioner asserted an additional anticipation challenge based on Ostler alone (Ground 3) and an obviousness challenge combining Baek and Sanpei for claim 4 (Ground 5).

4. Key Technical Contentions (Beyond Claim Construction)

  • Petitioner’s central technical argument was that the alleged invention of the ’929 patent was not an inventive step but rather a routine and obvious development following the maturation of GaN LED technology. Petitioner argued that the development of GaN LEDs in the mid-1990s—which inherently feature a built-in insulating sapphire substrate and have both electrical contacts on the top surface—eliminated the need for a separate ceramic insulating layer. This innovation naturally allowed for direct mounting onto metal substrates to improve heat dissipation, a technique Petitioner contended was well-known and widely disclosed in the prior art by the patent’s 2008 priority date.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-10 of the ’929 patent as unpatentable.