PTAB

IPR2013-00028

Chi Mei Innolux Corp v. Semiconductor Energy Laboratory Co Ltd

Log In

1. Case Identification

2. Patent Overview

  • Title: Contact Structure
  • Brief Description: The ’480 patent describes active matrix liquid crystal display (LCD) devices and methods for their manufacture. The invention purports to solve problems of non-uniform spacing between substrates in prior art LCDs by altering the placement of conductive spacers relative to an interlayer insulating film.

3. Grounds for Unpatentability

Ground 1: Claims 1, 5, 6, 10, 11, and 15 are obvious over the Admitted Prior Art in view of Moriyama.

  • Prior Art Relied Upon: Admitted Prior Art ("APA") of the ’480 patent (Patent 6,404,480) and Moriyama (Japanese Patent Publication No. JP 05-243333).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that the APA, which is described in detail within the ’480 patent’s specification (e.g., Fig. 13), discloses every element of the independent claims (1, 6, 11) except for the specific placement of the conductive spacers. The APA teaches placing conductive spacers within openings of a second interlayer insulating film. The key missing limitation is that "at least one of said conductive spacers is held over said second interlayer insulating film." Moriyama was argued to explicitly teach this missing element, disclosing an LCD structure where conductive spacers (metal particles 16) are held over an insulating film rather than in openings.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the teachings of the APA and Moriyama to solve the known problem of ensuring uniform and reliable electrical contact in LCDs. Moriyama’s approach of placing spacers over the insulating layer was presented as a known and logical design choice to improve electrical contact between opposing substrates, a goal directly relevant to the structure described in the APA.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in applying Moriyama's spacer placement to the APA's LCD structure, as both references relate to the same field of endeavor and address analogous problems of substrate connection and spacing.

Ground 2: Claims 2, 7, and 12 are obvious over the Admitted Prior Art in view of Moriyama and Ohno.

  • Prior Art Relied Upon: APA (Patent 6,404,480), Moriyama (Japanese Patent Publication No. JP 05-243333), and Ohno (Patent 4,600,273).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground builds upon Ground 1 to address dependent claims 2, 7, and 12, which further require that the conductive spacers are spheres coated with gold. Petitioner argued that while the APA and Moriyama establish the basic obviousness of the independent claims, Ohno supplies the teaching for this specific feature. Ohno was cited for its disclosure of using non-conductive core particles (e.g., plastic balls) made conductive by electroless plating with materials including gold to serve as contact media in a display panel.
    • Motivation to Combine: A POSITA, seeking to implement the conductive spacer connection taught by the combination of the APA and Moriyama, would have been motivated to use gold-coated spheres as taught by Ohno. Gold is a well-known material in the semiconductor art for its high conductivity and resistance to oxidation, making it an obvious choice for improving the reliability and performance of electrical contacts like the conductive spacers.
    • Expectation of Success: The use of gold-coated spheres for conductive spacers was a known and conventional technique, and a POSITA would have expected this straightforward substitution to function predictably within the combined APA/Moriyama structure.

  • Additional Grounds: Petitioner asserted additional obviousness challenges substituting Kitawada (Japanese Patent Publication No. JP 6-289415) for the APA as the primary reference. These grounds mirrored the logic of Grounds 1 and 2, arguing that Kitawada, like the APA, discloses a foundational LCD structure, which, when combined with Moriyama and/or Ohno, renders the challenged claims obvious.

4. Key Technical Contentions (Beyond Claim Construction)

  • Interpretation of the Admitted Prior Art: A central technical argument was that the APA (specifically, the prior art described within the ’480 patent) inherently discloses a "first interlayer insulating film," a required element of the claims. Petitioner contended that in a previous ex parte reexamination, the Patent Office declined a similar rejection because it was "unclear" if the ’480 patent admitted this specific layer. In the IPR petition, Petitioner supplied an expert declaration (Hatalis) to argue that a POSITA would have immediately recognized that a layer depicted in the APA’s prior art figure (between substrate 11 and conductive layer 21) must necessarily be an insulating film to prevent short-circuiting, thereby remedying the evidentiary gap identified in the prior reexamination.

5. Arguments Regarding Discretionary Denial

  • Related Litigation and Co-pending Applications: The petition was filed while the ’480 patent was involved in co-pending district court litigation (Semiconductor Energy Laboratory Co., Ltd. v. Chi Mei Innolux Corp., C.D. Cal.). Petitioner stated it would move to stay that litigation. Furthermore, Petitioner identified two co-pending, related divisional applications (12/257,514 and 12/257,521) and argued that the Board should exercise its jurisdiction over them. Petitioner asserted that allowing these applications to proceed to issuance during the IPR could lead to an "end-around" of the proceeding, where the Patent Owner could obtain claims indistinct from those being challenged. Petitioner requested the Board to suspend prosecution of these applications or require that any claim changes be authorized by the Board.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 2, 5-7, 10-12, and 15 of the ’480 patent as unpatentable under 35 U.S.C. §103.