PTAB

IPR2017-01499

Hutchinson Technology Incorporated v. Nitto Denko Corporation

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1. Case Identification

2. Patent Overview

  • Title: PRINTED CIRCUIT BOARD AND METHOD FOR MANUFACTURING SAME
  • Brief Description: The ’644 patent describes a printed circuit board for a hard disk drive suspension, specifically an integrated lead flexure. The invention focuses on an interleaved wiring pattern configuration designed to reduce the characteristic impedance of signal line pairs at a low cost.

3. Grounds for Unpatentability

Ground 1: Claims 1-4 are anticipated by Contreras under 35 U.S.C. §102.

  • Prior Art Relied Upon: Contreras (Patent 8,154,827).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Contreras, which discloses an integrated lead suspension with interleaved traces, teaches every limitation of claims 1-4. For independent claim 1, Petitioner asserted that Contreras’s flexure is a type of printed circuit board with an insulating layer. The "first and second wiring patterns" of the claim were mapped to Contreras's interleaved conductive traces (e.g., lines 71, 73, 75, 77 and 72, 74, 76, 78) which form a differential signal pair on the insulating layer. The claimed electrode pads were mapped to pads disclosed in Contreras (e.g., pads 54, 55, 56). Crucially, Petitioner contended that the claimed "first connecting layer" on the other side of the insulator is disclosed as the "island jumper 90" in Contreras, which is an isolated portion of the metal substrate used to create a crossover connection for the traces. The intricate arrangement of interleaved and branched lines recited in claim 1 was mapped element-by-element to the traces and connections shown in Contreras’s figures.
    • Key Aspects: The argument for dependent claims 2-4 built upon this mapping, asserting Contreras’s island jumper 90 also meets the limitations of a connecting layer composed of and separated from a metal layer (claim 2), and that Contreras’s disclosure of multiple crossover connections anticipates the second intersection region and connecting layer features (claims 3 and 4).

Ground 2: Claim 6 is obvious over Contreras in view of Pro under 35 U.S.C. §103.

  • Prior Art Relied Upon: Contreras (Patent 8,154,827) and Pro (Patent 8,379,349).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that while Contreras discloses the structure of the claimed printed circuit board, it does not explicitly teach a method of manufacturing it, as required by independent claim 6. Pro, however, remedies this deficiency by disclosing standard manufacturing techniques for a highly similar integrated lead flexure. Pro explicitly teaches using known additive and subtractive processes, such as photolithography, etching, and deposition, to fabricate flexures with interleaved traces and jumper constructions. Petitioner contended that the structural elements recited in method claim 6 are disclosed by Contreras, and the steps of "forming" these elements would have been obvious from the known manufacturing processes taught by Pro.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA), tasked with manufacturing the flexure structure disclosed in Contreras, would have been motivated to look to contemporaneous prior art like Pro. Because the flexures in both references are structurally similar—both including a metal substrate, insulating layer, interleaved traces, and jumper configurations—a POSITA would naturally apply the manufacturing processes described in Pro to build the device in Contreras.
    • Expectation of Success: Given that Pro describes conventional, well-known processes for fabricating nearly identical structures, a POSITA would have had a high and reasonable expectation of success in applying Pro’s methods to manufacture the Contreras device and thereby arrive at the method of claim 6.

Ground 3: Claims 1-4 and 6 are anticipated by Pro under 35 U.S.C. §102.

  • Prior Art Relied Upon: Pro (Patent 8,379,349).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Pro, by itself, anticipates all challenged claims. For apparatus claims 1-4, Petitioner mapped the claim limitations to Pro's disclosure of an integrated lead flexure. The "first and second wiring patterns" were mapped to Pro's interleaved transmission line arrays (e.g., traces 122a-d). The "connecting layer" was mapped to Pro’s "conductive island 118," which is part of its disclosed "jumper construction 100" and functions as a crossover. Petitioner argued that Pro discloses two such jumper constructions, one near the terminal connector pads and one near the head connector pads, which satisfy the requirements for the first and second intersection regions. For method claim 6, Petitioner argued Pro explicitly discloses the required manufacturing steps, stating its jumper constructions can be made using "known additive and/or subtractive processes" like photolithography and etching. Therefore, Pro was alleged to teach both the claimed structure and the method of making it.

4. Key Claim Construction Positions

  • "connecting layer": This term appears in claims 1-4 and 6. Petitioner argued it is central to the invalidity analysis and proposed it be construed as "a conductive layer that is part of the suspension body that allows electrical connection." This construction was asserted to be supported by the patent’s specification, which describes the connecting layer (RG1) as being formed from the metal suspension body (10). This construction is critical for Petitioner's arguments, as it allows the term to read on the "island jumper 90" of Contreras and the "conductive island 118" of Pro, both of which are formed from a substrate layer to create electrical crossover connections.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review for each ground presented and the cancellation of claims 1-4 and 6 of the ’644 patent as unpatentable.