PTAB

IPR2018-00965

Nichia Corporation v. Document Security Systems, Inc.

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1. Case Identification

2. Patent Overview

  • Title: Semiconductor Device With a Light Emitting Semiconductor Die
  • Brief Description: The ’787 patent discloses a semiconductor packaging device for a light-emitting diode (LED) intended for high-density applications. The invention features an LED die with both its anode and cathode contacts located on its bottom surface, which is then flip-chip mounted onto a packaging substrate that has interconnecting elements running through the substrate or along its sidewalls.

3. Grounds for Unpatentability

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

  • Prior Art Relied Upon: Lumbard (Patent Re. 36,614), 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 Lumbard taught a modular, surface-mountable semiconductor package with a substantially planar substrate, bonding pads on its top surface, connecting pads on its bottom surface, and interconnects in semi-cylindrical grooves along the substrate sidewalls, thus teaching most limitations of the challenged claims. However, Lumbard disclosed a conventional wire-bonded LED. Petitioner asserted that Weeks, Wirth, and Negley each independently disclosed a flip-chip style LED with both anode and cathode on its bottom surface, where that bottom surface is part of the LED's own substrate, as required by the claims.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the desirable, low-cost, mass-producible packaging substrate of Lumbard with the improved flip-chip LED design from Weeks, Wirth, or Negley. This combination would be motivated by the known advantages of flip-chip designs, such as creating smaller components and eliminating the top-side bond wire that can obstruct light emission, a recognized disadvantage of the LED used in Lumbard.
    • Expectation of Success: Petitioner contended that a POSITA would have a high expectation of success because the combination was a simple substitution of one known element (a wire-bonded LED) for another (a flip-chip LED) to obtain predictable results in a well-established and predictable technical field.

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

  • Prior Art Relied Upon: Ishidu (Application # 2006/0198162) in view of Weeks, Wirth, or Negley.
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Ishidu, as an alternative primary reference, taught a semiconductor device with a substrate having through-hole vias for interconnection and an LED flip-chip mounted thereon. Ishidu was argued to disclose nearly all elements of the claims, including the substrate, bonding pads, connecting pads, and through-substrate interconnects. Petitioner argued that Ishidu did not explicitly disclose that the LED's bottom surface (with the contacts) is a surface of the LED's own substrate.
    • Motivation to Combine: A POSITA would be motivated to use the specific LED structures from Weeks, Wirth, or Negley in the packaging assembly of Ishidu. Ishidu’s packaging was presented as desirable for its high thermal conductivity and ease of processing. The combination would predictably yield a device with the benefits of Ishidu's packaging and the improved electrical contact configuration of the secondary references.
    • Expectation of Success: As with the Lumbard combination, Petitioner argued this would be an obvious and predictable substitution of known components within the skill of a POSITA.

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

  • Prior Art Relied Upon: Ogawa (Application # 2006/0113906) in view of Weeks, Wirth, or Negley.
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner presented Ogawa as a further alternative primary reference teaching a light-emitting device with a face-down (flip-chip) mounted LED. Ogawa’s substrate included C-shaped interconnects running down its sidewalls. Petitioner argued Ogawa taught the claimed substrate and interconnect structure but, like Ishidu, did not explicitly detail that the LED's bottom contact surface was a surface of the LED's own substrate.
    • Motivation to Combine: A POSITA would be motivated to combine the LED designs of Weeks, Wirth, or Negley with the packaging assembly of Ogawa to achieve a device with Ogawa's stated benefits of "excellent heat resistance and light stability" and "simplified manufacturing" while incorporating a well-known, advantageous flip-chip LED configuration.
    • Expectation of Success: The combination was argued to be a straightforward substitution of compatible, known elements with a high likelihood of success.

4. Key Claim Construction Positions

  • "[top] major light emitting surface": Petitioner proposed this term be construed to mean "of the two largest faces of the LED, the face through which light is emitted."
  • "an oppositely-disposed [bottom] major surface": Correspondingly, this was proposed to mean "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": Proposed to mean "the face of the LED opposite the light emitting face is on the substrate side of the LED."
  • These constructions were central to Petitioner's arguments. They were used to distinguish the two different substrates at issue (the packaging substrate and the LED's own substrate) and to precisely orient the claimed LED structure for mapping onto the prior art references, particularly the flip-chip LEDs of Weeks, Wirth, and Negley.

5. Key Technical Contentions (Beyond Claim Construction)

  • Denial of Priority Date: A central contention was that the ’787 patent was not entitled to the earlier filing date of its parent application (the ’605 application). Petitioner argued that the parent application failed to provide adequate written description support for the key claim limitation of an LED having both an anode and a cathode on its bottom major surface. Because the parent allegedly only disclosed an LED with contacts on opposing surfaces, Petitioner argued the claims were new matter, limiting the ’787 patent to its actual filing date and making references like Ishidu and Ogawa available as prior art.

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.