PTAB

IPR2018-00265

Seoul Semiconductor Co Ltd v. Document Security Systems Inc

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Light Source
  • Brief Description: The ’771 patent describes a surface mount light-emitting diode (LED) package designed to improve heat dissipation. The invention features an LED mounted on a thermally conductive platform that extends through an aperture in a substrate, providing a direct thermal path away from the LED die to an external surface.

3. Grounds for Unpatentability

Ground 1: Obviousness over Sharp - Claims 1-9 are obvious over Sharp

  • Prior Art Relied Upon: Sharp (Japanese Patent Application Publication No. 07-235696).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Sharp discloses an LED package structure that is, for all relevant purposes, indistinguishable from that claimed in the ’771 patent. Sharp’s Figure 1 depicts a light source with an insulating substrate (10) having a through-hole aperture (12). A platform, comprising a thin metal sheet (5) and a plating layer, covers the bottom opening of the aperture and extends into it, with a portion located outside the aperture. An LED chip (1) is mounted on this platform within the aperture, and a transparent resin (11) encapsulates the LED. Petitioner contended this structure teaches all limitations of independent claims 1-8, including the platform being partially outside the aperture, the aperture having tapering sidewalls, and the platform extending over those sidewalls.
    • Motivation to Combine (for §103 grounds): This ground was asserted under 35 U.S.C. §103 based on a single reference. Petitioner argued that Sharp discloses every element of the claimed invention, and a person of ordinary skill in the art (POSITA) would have recognized that Sharp’s disclosed structure inherently performs the functions recited in the claims, such as providing a reflective surface and a thermally conductive path. For dependent claim 9, Petitioner argued Sharp discloses making the encapsulant into a lens shape to focus light, meeting the "focusing dome" limitation.
    • Expectation of Success (for §103 grounds): Because Sharp allegedly discloses a complete, working device embodying all claim limitations, a POSITA would have had a high expectation of success.

Ground 2: Obviousness over Stanley - Claims 1-8 are obvious over Stanley

  • Prior Art Relied Upon: Stanley (Japanese Patent Application Publication No. 11-284233).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Stanley, like Sharp, discloses a substantially similar LED package. Stanley’s Figure 1 shows a resin substrate (2) with a tapered through-hole aperture (2a). A platform, comprising a copper foil (4) and a conductive part (3a), covers the bottom opening of the aperture and extends over its inner sidewall. An LED chip (6) is mounted on the platform within the aperture and encapsulated by a transparent resin (8). Petitioner argued this structure teaches all limitations of the challenged claims, emphasizing Stanley’s explicit disclosure that the copper foil is exposed to the exterior to improve cooling efficiency, directly teaching the thermal dissipation function central to the ’771 patent.
    • Motivation to Combine (for §103 grounds): As a single-reference ground, the motivation was based on Stanley’s complete disclosure. Petitioner argued a POSITA would have understood Stanley’s integrated structure, with its explicit rationale for thermal management via the external copper foil, rendered the claims of the ’771 patent obvious.
    • Expectation of Success (for §103 grounds): A POSITA would have had a clear expectation of success in achieving the claimed device, as Stanley describes a functional LED element with all the required structural features.

Ground 3: Obviousness over Sharp in view of Konishi - Claim 9 is obvious over Sharp in view of Konishi

  • Prior Art Relied Upon: Sharp (Japanese Patent Application Publication No. 07-235696) and Konishi (Patent 5,635,115).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground specifically addressed the limitation in claim 9 requiring the encapsulant to be "molded to form a focusing dome." Petitioner argued that Sharp discloses that its transparent encapsulant can be "made to have a lens shape" to focus light but does not specify the manufacturing method. Konishi was cited for its teaching of using a known transfer molding process to form a focusing dome lens over an LED.
    • Motivation to Combine (for §103 grounds): A POSITA, seeking to implement the desirable "lens shape" taught by Sharp, would combine this with Konishi's well-known and efficient molding method. Konishi explicitly promoted molding as advantageous for mass production and for ensuring good adhesion and optical clarity, providing a strong rationale for its use. The ’771 patent itself characterizes its molding step as a "known transfer molding process," suggesting it was a conventional technique.
    • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success in applying the standard molding process from Konishi to the encapsulant of Sharp’s device, as it was a common and reliable technique for forming lenses on LEDs.
  • Additional Grounds: Petitioner asserted an additional obviousness challenge against claim 9 based on Stanley in view of Konishi, which relied on the same combination logic as Ground 3.

4. Key Claim Construction Positions

  • "said platform being located outside of said aperture": Petitioner argued for a broad construction of this term, critical to its invalidity arguments. Petitioner contended the phrase requires only that at least a portion of the platform is located outside the aperture, not the entire platform. This interpretation was supported by the ’771 patent’s specification and figures (e.g., Fig. 2), which show the platform (270) having a portion outside the substrate and another portion that extends into the aperture to form its floor (222) and cover its sidewalls (224). This construction allowed the structures in Sharp and Stanley, where the platform both covers the bottom opening and extends inside, to meet the claim limitation.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-9 of the ’771 patent as unpatentable.