DCT

2:16-cv-05948

SKC Kolon Pi Inc v. Kaneka Corp

Log In

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:16-cv-05948, C.D. Cal., 08/09/2016
  • Venue Allegations: Venue is alleged to be proper based on Defendant Kaneka's substantial revenue from sales in the district, its pursuit of legal actions in the district, and its prior enforcement of the patent-in-suit in the same district.
  • Core Dispute: Plaintiff seeks a declaratory judgment that its "redesigned" polyimide films do not infringe Defendant’s patent, following a prior jury verdict that found Plaintiff's earlier film designs to be infringing.
  • Technical Context: The lawsuit concerns high-performance polyimide films, a critical material used as a substrate for flexible printed circuit boards (FPCs) and other advanced electronic applications.
  • Key Procedural History: This action follows prior litigation between the parties. In an earlier case in the same district (2:11-cv-03397), a jury found on November 19, 2015, that certain of SKC Kolon PI's (SKPI) original polyimide films infringed the patent-in-suit. That verdict prompted SKPI to modify its manufacturing processes and films, leading to the "redesigned films" at issue in this new declaratory judgment action. The complaint also notes a prior, related ITC action where an Administrative Law Judge found claim 1 of the patent-in-suit invalid for lack of enablement, a determination the full Commission affirmed and Kaneka did not appeal.

Case Timeline

Date Event
2004-03-15 U.S. Patent No. 7,691,961 Earliest Priority Date
2010-04-06 U.S. Patent No. 7,691,961 Issues
2010-07-26 Kaneka files original infringement complaint against SKPI in E.D. Tex.
2011-03-31 Kaneka files related ITC complaint against SKPI
2012-10-05 ITC Commission affirms ALJ finding of non-infringement and invalidity of claim 1
2015-11-19 Jury verdict in C.D. Cal. finds prior SKPI films infringe the ’961 patent
2016-05-27 Kaneka sends correspondence to SKPI customers regarding the jury verdict
2016-08-09 SKC Kolon PI, Inc. files this Complaint for Declaratory Judgment

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 7,691,961 - Polyimide Film and Use Thereof, issued April 6, 2010

The Invention Explained

  • Problem Addressed: The patent describes a problem in manufacturing flexible printed circuits (FPCs), where the polyimide base film can change dimensions during metal lamination and etching processes. This dimensional instability, particularly non-uniformity across the width of the film due to a "bowing phenomenon" in manufacturing, makes it difficult to produce high-density circuits that require precise alignment (’961 Patent, col. 1:36-56, col. 3:28-40).
  • The Patented Solution: The invention provides a polyimide film, produced via a continuous process, with improved and stabilized dimensional properties. The solution is not a new chemical composition, but rather a film defined by specific physical characteristics. The patent teaches that by controlling either the ratio of the coefficients of linear expansion or the ratio of tear propagation resistance along different molecular axes to be within specific numerical ranges "across the entire width" of the film, the dimensional change during FPC manufacturing can be reduced and made uniform (’961 Patent, Abstract; col. 5:1-11; col. 6:34-49).
  • Technical Importance: Achieving uniform dimensional stability across a wide film roll was important because it allows for more reliable and higher-yield roll-to-roll processing of FPCs for high-density applications (’961 Patent, col. 1:50-56).

Key Claims at a Glance

  • The complaint asserts non-infringement of independent claims 1 and 9, and their corresponding dependent claims (Compl. ¶16).
  • Independent Claim 1:
    • A polyimide film produced by a continuous process,
    • wherein when a coefficient of linear expansion a [in the direction of the molecular orientation axis] and a coefficient of linear expansion b [in the perpendicular direction] are measured in the temperature range of 100° C. to 200° C.,
    • a coefficient of linear expansion ratio A, represented by the equation A=1+{(b-a)/(b+a)}x2,
    • is in the range of 1.13 to 3.00 across the entire width.
  • Independent Claim 9:
    • A polyimide film produced by a continuous process,
    • wherein when a tear propagation resistance c [in the direction of the molecular orientation axis] and a tear propagation resistance d [in the perpendicular direction] are measured,
    • the tear propagation resistance ratio d/c is in the range of 1.01 to 1.20, and
    • the difference between the maximum and the minimum of the tear propagation resistance ratio d/c is 0.10 or less across the entire width.
  • The complaint notes that because the independent claims are not infringed, the dependent claims (2-8 and 10-20) are also not infringed (Compl. ¶16).

III. The Accused Instrumentality

  • Product Identification: The products at issue are SKPI’s "redesigned films" (Compl. ¶14).
  • Functionality and Market Context: These are polyimide films that SKPI began manufacturing and selling after a November 2015 jury verdict found its previous film products infringed the ’961 Patent (Compl. ¶¶14, 18). The complaint alleges these redesigned films were developed to be commercially acceptable to customers while being "significantly and materially different" from the previously infringing films (Compl. ¶15). The core allegation is that these redesigned films were specifically engineered not to possess the physical characteristics claimed in the ’961 Patent (Compl. ¶15).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

The complaint seeks a declaratory judgment of non-infringement. The analysis below summarizes SKPI’s allegations that its redesigned films do not meet the limitations of the asserted claims, based on testing conducted by its expert (Compl. ¶¶ 14, 16).

  • ’961 Patent Infringement Allegations
Claim Element (from Independent Claim 1) Alleged Non-Infringing Functionality Complaint Citation Patent Citation
a polyimide film produced by a continuous process, wherein... a coefficient of linear expansion ratio A... is in the range of 1.13 to 3.00 across the entire width. SKPI's expert, Dr. Mecham, tested the redesigned films and concluded that they do not meet the claimed limitation for the coefficient of linear expansion ratio A being in the range of 1.13 to 3.00. ¶16 col. 37:1-11
Claim Element (from Independent Claim 9) Alleged Non-Infringing Functionality Complaint Citation Patent Citation
a polyimide film produced by a continuous process, wherein... the tear propagation resistance ratio d/c is in the range of 1.01 to 1.20 and the difference... is 0.10 or less across the entire width. SKPI's expert tested the redesigned films and concluded that they do not meet the claimed limitations for the tear propagation resistance ratio d/c or the difference between its maximum and minimum. ¶16 col. 37:34 - 38:2
  • Identified Points of Contention:
    • Factual/Evidentiary Question: The central dispute appears to be a factual one that will be resolved through expert testing and testimony. The complaint states that SKPI’s expert used "the same approach that Kaneka’s technical expert, Dr. Harris, used in the ongoing district court action" to conclude the redesigned films do not infringe (Compl. ¶14). This suggests the case will likely devolve into a "battle of the experts" over the test results of the redesigned films' physical properties.
    • Scope Question: A likely point of legal contention is the proper interpretation of the claim phrase "across the entire width." The resolution will determine whether the claimed properties must be met at every point, or if measurements at discrete representative points (e.g., ends and center, as described in the patent's specification) are sufficient to prove or disprove infringement.

V. Key Claim Terms for Construction

  • The Term: "across the entire width"

    • Context and Importance: This phrase appears in both asserted independent claims (1 and 9) and is fundamental to the scope of the invention. The dispute is whether SKPI's redesigned films exhibit the claimed physical property ratios within the specified ranges over the entire film width. The definition of this term will dictate the evidentiary burden for both parties.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The plain language of the phrase itself could be argued to mean at every point along the film's width direction.
      • Evidence for a Narrower Interpretation: The patent specification repeatedly describes a practical method of measuring physical properties at three points: "both end portions and the central portion" of the film (’961 Patent, col. 8:28-32, col. 8:58-64). A party could argue this disclosure defines "across the entire width" to mean compliance at these representative points, rather than at every infinitesimal point, which may be impractical to measure.

  • The Term: "coefficient of linear expansion ratio A"

    • Context and Importance: This is the dispositive technical limitation of claim 1. While the patent provides a formula, its application depends on the underlying measurements of the linear expansion coefficients 'a' and 'b'. Practitioners may focus on this term because any dispute over the proper methodology for measuring 'a' and 'b' would directly impact the calculated value of 'A' and the ultimate infringement determination.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: A party might argue for any scientifically valid method for measuring the underlying coefficients 'a' and 'b'.
      • Evidence for a Narrower Interpretation: The specification provides a detailed example of how to measure the thermal expansion coefficients, including the specific instrument (Seiko TMA120C), sample preparation, and heating protocol (’961 Patent, col. 8:45-64). A party could argue that this detailed description limits the scope of acceptable measurement techniques to those consistent with the patent's own example. The complaint’s reference to using the defendant’s expert’s prior "approach" indicates this methodological consistency is a recognized issue (Compl. ¶14).

VI. Other Allegations

The complaint is for a declaratory judgment of non-infringement and does not contain traditional allegations of infringement against the defendant. Instead, it alleges that the defendant, Kaneka, has created a justiciable controversy by threatening litigation.

  • Basis for Declaratory Judgment: SKPI alleges that a controversy exists because Kaneka sent correspondence to SKPI's customers stating that Kaneka "strongly believes" SKPI's new films still infringe and that Kaneka "intends to take legal action" (Compl. ¶18). This action, SKPI alleges, creates a reasonable apprehension of an infringement suit, thereby justifying the court's jurisdiction over this declaratory judgment action (Compl. ¶24).

VII. Analyst’s Conclusion: Key Questions for the Case

  • A central issue will be one of evidentiary proof: The case appears poised to become a "battle of the experts." The key question is whether SKPI’s testing data, which purports to show its redesigned films fall outside the patent's claimed numerical ranges, will be deemed credible and withstand Kaneka's own expert analysis and testing of the same products.
  • A key legal question will be one of claim scope: The interpretation of the phrase "across the entire width" will be critical. The court will need to decide whether this requires the claimed physical properties to hold true at every point on the film, or if it is satisfied by testing at the discrete, representative locations (ends and center) described as the measurement method in the patent's specification. This determination will define the scope of evidence required to establish non-infringement.