PTAB

IPR2019-00506

Cree Inc v. Document Security Systems Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Packaging Device for Semiconductor Die, Semiconductor Device Incorporating Same and Method of Making Same
  • Brief Description: The ’486 patent discloses a substrate packaging assembly for a light-emitting diode (LED). The assembly includes a planar substrate with top-side mounting and bonding pads and bottom-side connecting pads, where electrically conductive interconnecting elements extend through the substrate to connect the top and bottom pads.

3. Grounds for Unpatentability

Ground 1: Obviousness over Nakajima and Weeks - Claims 1-5 are obvious over Nakajima in view of Weeks.

  • Prior Art Relied Upon: Nakajima (Japanese Patent Application No. 2002-232017) and Weeks (Patent 6,611,002).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Nakajima discloses a substrate packaging assembly for an LED that meets nearly all limitations of independent claim 1. Nakajima teaches a planar ceramic substrate with a mounting pad on its top surface, a connecting pad on its bottom surface, and a through-hole interconnecting element connecting them. However, Nakajima is silent on the specific structure of its LED’s top and bottom surfaces. Petitioner asserted that Weeks discloses an LED with metallized top and bottom major surfaces, where the bottom surface serves as a backside electrical contact (e.g., a cathode) and the top surface includes a topside electrical contact (e.g., an anode). The combination of Nakajima’s packaging assembly with the LED taught by Weeks allegedly renders claims 1-5 obvious. For dependent claims 4 and 5, Petitioner argued Nakajima itself teaches using tungsten for the interconnecting elements to withstand high temperatures and provide low resistance.
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would combine these references as a simple substitution of one known element for another. A POSITA would have been motivated to mount a well-known LED, like the one in Weeks, onto a suitable packaging substrate, like the one in Nakajima, to create a functional device for display or illumination. The packaging assembly of Nakajima was an attractive choice because it was designed to increase luminous efficacy.
    • Expectation of Success: The substitution was argued to be a routine design choice, well within the skill of a POSITA, with a reasonable expectation of success. The components were known to be compatible, and using metallized electrodes as taught by Weeks was known to create strong bonds with mounting pads and improve thermal dissipation.

Ground 2: Obviousness over Rohm and Weeks - Claims 1-3 are obvious over Rohm in view of Weeks.

  • Prior Art Relied Upon: Rohm (Japanese Patent Application Publication No. 2003-17754) and Weeks (Patent 6,611,002).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted an argument parallel to Ground 1, but using Rohm as the primary reference. Rohm was argued to disclose a surface-mount semiconductor device with a substrate, a die bonding electrode (mounting pad), a wire bonding electrode (bonding pad), and interconnecting electrodes extending through the substrate. Like Nakajima, Rohm discloses a full packaging assembly but is silent on whether its LED’s bottom surface is metallized. Petitioner contended that substituting the LED from Weeks, which explicitly teaches a metallized bottom major surface functioning as an electrode, into Rohm’s device would render claims 1-3 obvious.
    • Motivation to Combine: The motivation was again presented as a simple substitution of a known LED (from Weeks) into a known packaging assembly (from Rohm). Petitioner argued a POSITA would be motivated to use Rohm’s assembly because its design increased packaging density on a circuit board, a known benefit in the field.
    • Expectation of Success: Petitioner asserted a reasonable expectation of success for the same reasons as in Ground 1, as it involved combining known, compatible components to achieve predictable results.

Ground 3: Obviousness over Nakajima, Weeks, and Jochym - Claim 6 is obvious over Nakajima in view of Weeks and Jochym.

  • Prior Art Relied Upon: Nakajima (Japanese Patent Application No. 2002-232017), Weeks (Patent 6,611,002), and Jochym (Patent 6,747,217).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground builds on the combination of Nakajima and Weeks to address claim 6, which adds the limitation that the interconnecting element is a “slug of electrically conductive material” that is “press-fit” into a through-hole. Petitioner argued that while Nakajima’s interconnect is formed by screen-printing a metallized paste, Jochym explicitly teaches an alternative method for creating through-hole interconnects in printed circuit boards. Jochym discloses placing a conductive stake or pin into a through-hole using a "press fit" to solve problems associated with plating thick substrates.
    • Motivation to Combine: Petitioner argued that press-fitting a conductive slug (as taught by Jochym) was a known alternative to plating or using paste (as in Nakajima) for forming electrical interconnects. A POSITA seeking to create a robust connection in the ceramic substrate of Nakajima would have found it obvious to substitute the known technique from Jochym. This substitution would have been motivated by the desire to use a simple, effective interconnection method known to maintain small via diameters in thick substrates.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in applying Jochym’s press-fit slug method to Nakajima’s substrate, as it was a known, interchangeable manufacturing technique for achieving a common goal.

  • Additional Grounds: Petitioner asserted numerous additional obviousness challenges based on various combinations of primary references (Nakajima, Rohm, Matsushita), secondary references disclosing the claimed LED structure (Weeks, Kish, Edmond), and tertiary references for specific features (Jochym for claim 6). The core arguments across all grounds relied on the same theories of simple substitution of known elements to arrive at the claimed invention.

4. Key Claim Construction Positions

  • "major surface": Petitioner argued this term should be construed according to its plain and ordinary meaning as "a face that is greater in size than the other faces of the element being described." This construction was based on the geometric orientation of the substrate and LED as described in the ’486 patent’s specification.
  • "metallized ... major surface": Petitioner proposed this term be construed to mean "a major surface having metal on at least a portion thereof." This construction was asserted to be critical, as it meant the claim limitation did not require the entire surface to be metal, thereby bringing prior art references with partial metallization (e.g., only a bonding pad) within the scope of the claims.

5. Arguments Regarding Discretionary Denial

  • Petitioner noted that all grounds asserted in its petition were identical to those brought by Nichia Corporation in a previously instituted IPR (IPR2018-01166). Petitioner filed the instant petition concurrently with a Motion for Joinder to that proceeding, arguing that institution and joinder were appropriate and would not present any new or otherwise adjusted grounds for the Patent Owner to address.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-6 of the ’486 patent as unpatentable under 35 U.S.C. §103.