PTAB

IPR2013-00108

Analog Devices Inc v. Knowles Electronics LLC

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1. Case Identification

2. Patent Overview

  • Title: Miniature Silicon Condenser Microphone
  • Brief Description: The ’616 patent discloses a package for a transducer, such as a MEMS microphone. The technology involves mounting a transducer on a substrate with an aperture, enclosing it with a cover to define a volume, and using a sealing ring on the opposite side of the substrate to surround the aperture.

3. Grounds for Unpatentability

Ground 1: Obviousness over Giasolli in view of Kaschke - Claim 2 is obvious over Giasolli in view of Kaschke.

  • Prior Art Relied Upon: Giasolli (a 2000 MEMS packaging presentation) and Kaschke (Patent 5,999,821).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Giasolli, a presentation on MEMS packaging, disclosed all elements of claim 1, upon which challenged claim 2 depends. Giasolli’s slide 41 illustrated a MEMS acoustic sensor (transducer) mounted on a conductive lead frame (substrate) adjacent to an aperture. A plastic cap (cover) was secured to the substrate to define a volume for the transducer. Petitioner contended that a layer labeled "Adhesive" shown on the bottom of the substrate surrounding the aperture functioned as the claimed "sealing ring." The additional limitation of claim 2—that the transducer "completely covering the aperture"—was met because such an arrangement is necessary for the transducer's diaphragm to react to pressure differentials between the front and back volumes.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would look to Kaschke to understand the function of adhesive elements in acoustic transducer packages. Kaschke explicitly taught that an adhesive layer arranged at the periphery of a microphone aperture provides an "acoustic seal." Petitioner asserted a POSITA would thus be motivated to apply Kaschke's explicit teaching of an adhesive's sealing function to the analogous adhesive structure in Giasolli to ensure a proper acoustic seal, a known requirement for microphone performance.
    • Expectation of Success: A POSITA would have a high expectation of success, as combining the teachings merely involved recognizing the known sealing function of an adhesive ring in a microphone package, as explicitly described by Kaschke.

Ground 2: Obviousness over Henning 1 and Henning 2 in view of Harris - Claim 2 is obvious over Henning 1 and Henning 2 in view of Harris.

  • Prior Art Relied Upon: Henning 1 (a 1998 IEEE paper), Henning 2 (a 1998 IEEE paper), and Harris (Patent 5,865,417).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Henning 1 and Henning 2, which describe the same microfluidic mass flow controller (MFC) device, collectively disclosed most elements of the challenged claim. The references showed transducers (a pressure sensor and a valve) mounted on a ceramic substrate with apertures. A metal lid (cover) hermetically sealed the transducers within a defined volume. On the bottom surface of the substrate opposite the volume, Henning showed black ovals surrounding the apertures. Petitioner asserted these ovals corresponded to the claimed sealing ring. The additional limitation of claim 2—the transducer "completely covering the aperture"—was met because it was necessary to maintain a vacuum reference pressure within the hermetic volume and to prevent gas from leaking out of the flow channel. Harris, which discloses a remarkably similar microfluidic valve, was cited to explicitly teach the use of "O-rings" for sealing when the device is bolted to a gas manifold.
    • Motivation to Combine: A POSITA would combine the teachings because Henning 1/2 and Harris disclose highly similar devices intended for the same purpose: mounting on a manifold to control gas flow. The operational requirements of such a device necessitate a reliable seal to prevent leaks. Harris explicitly taught using O-rings to create this seal. A POSITA would have been motivated to apply the explicit O-ring teaching from Harris to the analogous structures (black ovals) in Henning to ensure the known, necessary function of a leak-proof seal between the device and a manifold.
    • Expectation of Success: A POSITA would have expected success in applying Harris’s O-ring sealing solution to Henning's device, as it was a straightforward application of a known sealing component to a nearly identical structure to achieve the predictable result of a sealed gas channel.

4. Key Claim Construction Positions

  • "package": Petitioner argued that the preamble term "package" was not a limitation of the claim, as it merely stated the intended use of the invention and was not recited in the body of the claim.
  • "substrate": Petitioner asserted that the term "substrate" should be construed broadly. In support, Petitioner pointed to statements made by the Patent Owner during a co-pending reexamination, where the Patent Owner allegedly conceded that the term "substrate" in the claim was broad enough to encompass the "lead frame" disclosed in the Giasolli reference. This construction was central to Petitioner's mapping of Giasolli to the claim limitations.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claim 2 of the ’616 patent as unpatentable.