PTAB

IPR2018-00526

Xilinx Inc v. Anza Technology Inc

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Key Events
Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Electrically Dissipative Ceramic Bonding Tips
  • Brief Description: The ’548 patent is directed to a method of using a bonding tool tip that is "electrically dissipative" to connect integrated circuits. The method purports to allow an essentially smooth electrical current to dissipate from the device being bonded, which is claimed to be low enough to prevent damage to the device but high enough to avoid a damaging buildup of electrostatic charge.

3. Grounds for Unpatentability

Ground 1: Claim 3 is anticipated by Yamamoto under 35 U.S.C. §102.

  • Prior Art Relied Upon: Yamamoto (International Publication No. WO 97/45867).
  • Core Argument:
    • Prior Art Mapping: Petitioner argued that Yamamoto, which was not considered during original prosecution, discloses every limitation of claim 3. Yamamoto teaches a method of using a bonding tool tip to bond a semiconductor chip to a substrate. The tip disclosed in Yamamoto possesses a layered structure—boron-doped polycrystalline diamond films surrounding an insulative silicon carbide (SiC) core—that is functionally and structurally identical to a dissipative configuration described in the ’548 patent. Petitioner asserted that Yamamoto’s objective of preventing "dielectric breakdown" and suppressing sparks inherently teaches the claimed functional result of allowing an "essentially smooth current" to dissipate. Furthermore, Petitioner contended that "concrete Example 3" in Yamamoto describes a tip structure with specific layer thicknesses and resistivities that result in an overall resistance falling within the 10⁵ to 10¹² ohm range identified as optimal in the ’548 patent specification.

Ground 2: Claim 3 is obvious over Linn in view of Popp under 35 U.S.C. §103.

  • Prior Art Relied Upon: Linn (Patent 5,816,472) and Popp (DE 3743630).
  • Core Argument:
    • Prior Art Mapping: Petitioner asserted that Linn discloses a method of using a bonding tool with a tip made from aluminum oxide ceramic to bond a semiconductor device. While Linn teaches the use of the ceramic tip, it does not explicitly state that the material is electrically dissipative. Popp addresses this missing element by teaching the use of dissipative materials for tools that handle electrostatically sensitive components to prevent damage from static discharge. Specifically, Popp discloses making tool tips from a wear-resistant ceramic, including doped aluminum oxide, with a defined surface resistivity between 10⁵ and 10¹² ohms. This resistivity range inherently provides the claimed functional behavior: allowing a smooth current to dissipate that is low enough to prevent damage but high enough to prevent charge buildup.
    • Motivation to Combine: Petitioner argued a Person of Ordinary Skill in the Art (POSA) would have been motivated to modify Linn’s aluminum oxide bonding tip with the dissipative properties taught by Popp. The motivation stems from the desire to solve the well-known problem of electrostatic discharge (ESD) damage during the handling and assembly of sensitive electronic components, a problem Popp directly addresses. A POSA would have recognized that the aluminum oxide tip in Linn could be improved by incorporating Popp’s teachings on making that same type of ceramic dissipative. This would be a simple and logical substitution of an improved material to gain a predictable benefit (ESD protection) in the same field of art.
    • Expectation of Success: A POSA would have had a high expectation of success in combining the references. The combination merely applies a known technique (doping a ceramic to make it dissipative) to a known device (Linn’s ceramic bonding tip) to achieve a predictable and desired result (preventing ESD damage during bonding). Popp expressly teaches that doping aluminum oxide achieves the necessary dissipative properties, removing any uncertainty and providing a clear path to the claimed invention.

4. Key Claim Construction Positions

  • Petitioner submitted that the terms of claim 3 should be given their ordinary and customary meanings and that no special construction is required to find the claim invalid.
  • However, Petitioner noted that in prior district court litigation involving the ’548 patent, certain terms were construed. For "dissipative material," the patentee proposed "a material having an electrical resistance between that of insulative and conductive materials." For "essentially smooth current," the parties agreed on "a discharge of electrical current that avoids sudden surges."
  • Petitioner argued that the Broadest Reasonable Interpretation (BRI) standard applicable in an inter partes review (IPR) would result in constructions at least as broad as those used in prior litigation, further supporting its invalidity contentions.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claim 3 of the ’548 patent as unpatentable under §102 and §103.