FormFactor Inc v. Technoprobe Spa

1. Case Identification

• Case #: IPR2024-00933
• Patent #: 11,035,885
• Filed: June 28, 2024
• Petitioner(s): FormFactor, Inc.
• Patent Owner(s): Technoprobe S.p.A.
• Challenged Claims: 1-23

2. Patent Overview

• Title: Testing Head for Electronic Devices
• Brief Description: The ’885 patent relates to testing heads used to verify the operation of semiconductor devices on a wafer. The patent’s purported invention is the addition of dedicated conductive portions on a probe guide, where each portion electrically connects a group of guide holes housing contact probes that carry the same type of signal (e.g., one portion for ground signals and a second for power signals).

3. Grounds for Unpatentability

Ground 1: Anticipation over Kim - Claims 1-2, 4, 8-11, and 14 are anticipated by Kim.

• Prior Art Relied Upon: Kim (Application # 2015/0198632).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kim discloses every element of the challenged claims. Kim teaches a semiconductor testing apparatus with a guide plate containing conductive layers within its guide holes and conductive traces on its surface. These conductive elements electrically connect groups of testing pins that carry the same signal. Specifically, Petitioner asserted that Kim's Figures 5a and 5b show a first conductive portion connecting ground pins on the upper surface of a guide plate and a second conductive portion connecting power pins on the opposite lower surface, meeting the limitations of independent claim 1. For dependent claim 2, Petitioner identified a gap in Kim's conductive trace as a "non-conductive zone." For claim 4, Petitioner mapped Kim's disclosure of conductive portions on opposite upper and lower surfaces of the guide plate.
  • Key Aspects: Petitioner emphasized that patent offices in Europe and Japan had already rejected counterpart applications to the ’885 patent as lacking novelty over Kim, and that the Patent Owner had acknowledged Kim’s disclosure of the key features during those proceedings.

Ground 2: Obviousness over Kim and Schmid - Claims 5-6, 16-20, and 23 are obvious over Kim in view of Schmid.

• Prior Art Relied Upon: Kim (Application # 2015/0198632), Schmid (Patent 6,417,684).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addressed claims requiring a three-guide structure (lower, intermediate, and upper guides). Petitioner contended that Kim discloses the foundational testing head with metallized guides, as established in Ground 1. Schmid was cited for its explicit teaching that using three guide panels is preferable to two for ensuring contact elements do not touch, improving electrical insulation and reducing cost. The combination of Kim’s conductive portions with Schmid’s three-guide structure would allegedly render the subject matter of these claims obvious.
  • Motivation to Combine: A POSITA would combine these references because both address the same field of buckling beam probe heads and seek to improve performance. Petitioner argued that adding a third, intermediate guide as taught by Schmid to Kim’s two-plate design was a well-known and predictable design choice to enhance probe stability and alignment.
  • Expectation of Success: The combination was presented as a straightforward application of known design principles, with a high expectation of success in achieving the predictable benefits of improved probe stability (from Schmid) and enhanced signal integrity (from Kim).

Ground 3: Obviousness over Kim and Bross - Claims 12 and 13 are obvious over Kim in view of Bross.

• Prior Art Relied Upon: Kim (Application # 2015/0198632), Bross (Patent 5,225,777).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground challenged claims requiring the conductive portion to be "embedded" (claim 12) or part of an "overlapped and electrically insulated" plurality (claim 13). Petitioner argued that while Kim teaches forming conductive portions on the surface of a guide plate, Bross teaches a well-known multi-layer fabrication technique where alternating conductive and insulating layers are laminated together. This process inherently results in conductive portions being embedded within the body of the probe assembly.
  • Motivation to Combine: A POSITA would be motivated to apply the well-known laminating and multi-layer manufacturing methods taught by Bross to Kim's design. This would be a predictable selection of a known manufacturing technique to create a more robust and integrated structure, resulting in the claimed embedded and overlapping conductive portions.
  • Expectation of Success: Given that Bross describes multi-layer fabrication as a well-known technique for probe assemblies, a POSITA would have reasonably expected success in applying it to form the conductive portions taught by Kim.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including: Kim rendering claims obvious (Ground 2); Kim in view of Fan (Patent 9,470,715) for a dielectric coating (Ground 4); Kim in view of the 2016 SWTest Presentation for adding a circuit component (Ground 6); and Kim in view of Bross and Schmid (Ground 7). These grounds relied on similar modification theories to solve known problems in the art.

4. Key Claim Construction Positions

• “common pad” (claims 9, 10, 19, 20): Petitioner proposed construing this term as a "terminal for mechanical and electrical contact between two electrical components that allows access to the contact elements directly from the housing of the testing head." This construction was argued to be critical because it allows Kim’s disclosure of a conductive trace extending to an external area on the guide plate (for connection to a main board) to be interpreted as the claimed "common pad," thereby anticipating claims reciting this feature.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under Fintiv is unwarranted. The scheduled trial date in the parallel district court litigation (February 2, 2026) is well after the statutory deadline for a Final Written Decision in this IPR. Furthermore, investment in the parallel proceeding was asserted to be minimal, as invalidity contentions had not yet been served and claim construction had not begun. Petitioner also stipulated that it will not pursue in the district court any invalidity grounds on which IPR is instituted. Finally, Petitioner argued the petition is particularly strong, citing the fact that foreign patent offices have already found claims unpatentable over Kim. Denial under §325(d) was also argued to be inappropriate because Kim was not considered during prosecution of the ’885 patent.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-23 of the ’885 patent as unpatentable.