PTAB

IPR2018-00528

Xilinx Inc v. Anza Technology Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Electrically Dissipative Ceramic Bonding Tips
  • Brief Description: The ’479 patent describes bonding tips for use in semiconductor manufacturing that are made from electrically dissipative ceramic materials. The invention aims to prevent damage to sensitive electronic devices from electrostatic discharge (ESD) by allowing static charge to dissipate slowly from the bonding tip.

3. Grounds for Unpatentability

Ground 1: Claims 37, 38, and 50 are obvious over Yamamoto

  • Prior Art Relied Upon: Yamamoto (International Publication No. WO 97/45867).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Yamamoto, which was not considered during original prosecution, disclosed a method of using a bonding tip for semiconductor chips that meets all limitations of the challenged claims. Yamamoto’s tip was described as having a layered structure—boron-doped polycrystalline diamond films on an insulative silicon carbide (SiC) core—that renders it dissipative. This structure allegedly managed ESD by having a resistance low enough to prevent catastrophic spark discharge but high enough to prevent current flow that could damage the device. Petitioner contended that a person of ordinary skill in the art (POSITA) would understand that selecting a commercially available SiC material for Yamamoto’s insulative core would result in a bonding tip with a total resistance falling within the range of 10⁵ to 10¹² ohms recited in dependent claim 38.
    • Motivation to Combine: This ground relied on a single reference. The motivation was framed as an obvious design choice. Petitioner asserted a POSITA would have been motivated to select a specific, known insulative SiC substrate for Yamamoto’s core to achieve predictable and optimal insulative properties, which in turn would result in a dissipative bonding tip meeting the claimed resistance range.
    • Expectation of Success: Petitioner argued a POSITA would have had a high expectation of success because the properties of various SiC materials were well-known. Selecting a known material to function as an insulator in Yamamoto's disclosed structure would predictably result in a tool with the desired dissipative characteristics.

Ground 2: Claims 37, 38, and 50 are obvious over Linn in view of Popp

  • Prior Art Relied Upon: Linn (Patent 5,816,472) and Popp (DE 3743630).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Linn disclosed a method of bonding semiconductor devices using a bonding tip made of aluminum oxide ceramic. While Linn did not explicitly state its tip was dissipative, Popp taught the use of dissipative materials for tools that handle electrostatically sensitive components to prevent ESD damage. Popp specifically disclosed using wear-resistant ceramics, including doped aluminum oxide, with a surface resistivity between 10⁵ and 10¹² ohms—the exact range of claim 38. The argument was that the combination of Linn’s bonding tool with Popp’s teachings on dissipative materials for handling sensitive components rendered the claims obvious.
    • Motivation to Combine: A POSITA would combine Linn and Popp to gain the known benefit of ESD protection. Popp explicitly addressed the problem of ESD damage during the handling of sensitive components, a problem directly relevant to the bonding process in Linn. A POSITA would have been motivated to incorporate Popp’s teaching of using a dissipative ceramic into Linn’s aluminum oxide bonding tip to prevent such damage. This was presented as a straightforward application of a known solution (dissipative surfaces) to a known problem (ESD in component handling) in a known device (ceramic bonding tip).
    • Expectation of Success: Success would have been expected because Popp taught that doped aluminum oxide—the same base material used in Linn's tip—could achieve the desired dissipative properties and resistivity range. Therefore, modifying Linn’s tip according to Popp’s teachings was a predictable combination of known elements that would yield the claimed invention.

4. Key Claim Construction Positions

  • Petitioner asserted that no special constructions were necessary to find the claims invalid, but highlighted constructions for several terms that the Patent Owner had previously proposed in district court litigation. Petitioner argued the Broadest Reasonable Interpretation (BRI) standard in an inter partes review (IPR) would be at least as broad as these constructions.
  • "dissipative material": Construed as "a material having an electrical resistance between that of insulative and conductive materials." This construction was central to mapping the prior art, which described materials with specific, intermediate resistivity values.
  • "in the range of 10⁵ to 10¹² ohms": Construed as a range inclusive of its endpoints. This was critical for the argument that Popp’s disclosed range of "between 10⁵ and 10¹² ohms" and the calculated resistance for the modified Yamamoto reference met the limitation of claim 38.

5. Arguments Regarding Discretionary Denial

  • The petition extensively detailed the history of a prior inter partes reexamination of the ’479 patent. Petitioner argued that in that proceeding, the Examiner had rejected the challenged claims over different prior art combinations. According to the petition, the Patent Owner only terminated those proceedings by settling with the requester after receiving an unfavorable Action Closing Prosecution, thus preventing a final written decision on the merits. Petitioner highlighted that its current grounds relied on new prior art (Yamamoto and Popp) not asserted in the original prosecution or the prior reexamination, strengthening the case for institution.

6. Relief Requested

  • Petitioner requested the institution of an IPR and the cancellation of claims 37, 38, and 50 of the ’479 patent as unpatentable.