DCT

1:21-cv-00052

Nidec Corp v. Seagate Technology LLC

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:21-cv-00052, D. Del., 01/18/2021
  • Venue Allegations: Venue is alleged to be proper against Seagate Technology LLC because it is a Delaware limited liability company residing in the district. Venue is alleged against the foreign defendants on the basis that venue is proper in any judicial district for a foreign corporation.
  • Core Dispute: Plaintiff alleges that Defendant’s hard disk drives (HDDs) infringe five patents related to spindle motor design, manufacturing processes, and base plate construction.
  • Technical Context: Spindle motors are the precision components within HDDs responsible for rotating the magnetic data platters at thousands of revolutions per minute, a function critical to data storage and retrieval.
  • Key Procedural History: The complaint does not allege any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history between the parties concerning the patents-in-suit.

Case Timeline

Date Event
2012-11-19 U.S. Patent No. 8,737,017 Priority Date
2014-05-27 U.S. Patent No. 8,737,017 Issued
2014-12-04 U.S. Patent No. 9,742,239 Priority Date
2014-12-05 U.S. Patent No. 9,935,528 Priority Date
2017-08-22 U.S. Patent No. 9,742,239 Issued
2017-09-22 U.S. Patent No. 10,407,775 Priority Date
2017-11-08 U.S. Patent No. 10,460,767 Priority Date
2018-04-03 U.S. Patent No. 9,935,528 Issued
2019-09-10 U.S. Patent No. 10,407,775 Issued
2019-10-29 U.S. Patent No. 10,460,767 Issued
2021-01-18 Complaint Filing Date

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

U.S. Patent No. 8,737,017 - "Spindle Motor and Disk Drive Apparatus"

  • Patent Identification: U.S. Patent No. 8,737,017, "Spindle Motor and Disk Drive Apparatus", issued May 27, 2014 (Compl. ¶40).

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of designing thinner spindle motors for compact disk drives without compromising performance (Compl. ¶41). Reducing motor thickness can disproportionately decrease the torque constant (Kt), which in turn increases the "startup time" required for the disk to reach its operational speed (Compl. ¶41; ’017 Patent, col. 1:20-25).
  • The Patented Solution: The invention proposes a thin spindle motor design that achieves sufficient torque by defining specific relationships between structural dimensions and performance characteristics. The solution specifies a height of the stator core relative to the overall stator height, and defines ranges for the motor's torque constant (Kt) and motor constant (Km) to ensure both adequate torque and a short startup time (Compl. ¶42; ’017 Patent, Abstract). The specification describes an outer rotor-type motor where the rotor magnet is positioned outside the stator in a radial direction (’017 Patent, col. 2:5-10).
  • Technical Importance: This approach enabled the production of thinner HDDs essential for compact electronics, while maintaining the quick startup performance users expect (Compl. ¶42).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶24).
  • Essential elements of Claim 1 include:
    • A base unit.
    • A stator including a stator core and coils, disposed above the base unit.
    • A covered cylindrical rotor hub including a cover portion above the stator and a side wall portion extending downward.
    • A rotor magnet positioned outside the stator and fixed to an inner circumferential surface of the side wall portion.
    • A bearing mechanism supporting the rotor hub to be rotatable.
    • A height of the stator core in an axial direction is about 50% or more and about 70% or less than a height of the stator.
    • A torque constant Kt is about 4 mN·m/A or more and about 6 mN·m/A or less.
    • A motor constant Km is about 2 mN·m/(A·√Ω) or more and about 4 mN·m/(A·√Ω) or less.

U.S. Patent No. 9,742,239 - "Spindle Motor and Disk Drive Apparatus"

  • Patent Identification: U.S. Patent No. 9,742,239, "Spindle Motor and Disk Drive Apparatus", issued August 22, 2017 (Compl. ¶43).

The Invention Explained

  • Problem Addressed: The patent identifies two problems that arise when passing a motor's lead wire through a hole in the metal base of an HDD. First, the wire's insulation coating can be damaged by contact with the sharp edge of the hole, potentially causing a short circuit. Second, in sealed, gas-filled drives (e.g., helium-filled), any gap between the wire and the hole can allow the specialized gas to leak out or contaminants to enter (Compl. ¶44).
  • The Patented Solution: The invention discloses a sealing and protection system for the lead wire pass-through. It involves an insulation sheet portion on the lower surface of the base, a "first sealant" located within the through-hole, and a "second sealant" that covers the hole. The solution specifies that the first sealant has a coefficient of linear expansion greater than the base portion but smaller than the second sealant, a design intended to manage thermal stresses and maintain a reliable seal (Compl. ¶44; ’239 Patent, Abstract).
  • Technical Importance: This invention improves the long-term reliability of modern, high-capacity, gas-filled HDDs by preventing electrical malfunctions and ensuring the integrity of the sealed internal environment (Compl. ¶44).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶27).
  • Essential elements of Claim 1 include:
    • A rotor portion, a bearing portion, a metal base portion, a stator portion, a circuit board, an insulation sheet portion, a first sealant, and a second sealant.
    • The base portion includes a through-hole.
    • The coils include a lead wire drawn out from above the upper surface, through the base portion through-hole.
    • The circuit board includes a land portion to which the lead wire is connected.
    • The insulation sheet portion is on the lower surface, covers at least a portion of the through-hole, and contacts the lead wire.
    • The first sealant is located in the through-hole.
    • The second sealant covers at least a portion of the through-hole.
    • The first sealant has a coefficient of linear expansion greater than that of the base portion and smaller than that of the second sealant.

U.S. Patent No. 9,935,528 - "Spindle Motor and Disk Drive Apparatus"

  • Patent Identification: U.S. Patent No. 9,935,528, "Spindle Motor and Disk Drive Apparatus", issued April 3, 2018 (Compl. ¶45).
  • Technology Synopsis: This patent addresses the technical problem of potential damage to a lead wire's insulation coating where it passes through a hole in the spindle motor's base portion (Compl. ¶46). The patented solution involves using an "insulation sheet portion" that covers the hole and contacts the lead wire, with the insulation sheet having a thickness greater than the circuit board's land portion, thereby preventing damage and short circuits (Compl. ¶46; ’528 Patent, Abstract).
  • Asserted Claims: Claim 1 (Compl. ¶30).
  • Accused Features: The spindle motor within the Seagate 16TB IronWolf Pro HDD is accused of infringing. The allegations focus on the motor's use of an insulation sheet to protect the lead wire as it passes through the base, where the insulation sheet is alleged to be thicker than the circuit board's land portion (Compl. ¶110, ¶115).

U.S. Patent No. 10,407,775 - "Base Plate, Hard Disk Drive, and Method of Manufacturing Base Plate"

  • Patent Identification: U.S. Patent No. 10,407,775, "Base Plate, Hard Disk Drive, and Method of Manufacturing Base Plate", issued September 10, 2019 (Compl. ¶47).
  • Technology Synopsis: This patent is directed to improving the airtightness of housings for gas-filled HDDs to reduce windage loss (Compl. ¶48). The invention describes a base plate made by casting, which is then treated with both an "electrodeposition coating film" and an "impregnant." The impregnant is arranged to cover worked surfaces exposed from the coating film, sealing minute cavities and thereby improving the overall airtightness of the drive's interior space (Compl. ¶48).
  • Asserted Claims: Claim 9 (Compl. ¶33).
  • Accused Features: The base plate of the Seagate 16TB IronWolf Pro HDD is accused of infringing. The complaint alleges the base plate is a cast body featuring a coated surface covered with an electrodeposition film and a flat worked surface covered with an impregnant to enhance airtightness (Compl. ¶127-131).

U.S. Patent No. 10,460,767 - "Base Member Including Information Mark and Insulating Coating Layer, and Disk Drive Apparatus Including the Same"

  • Patent Identification: U.S. Patent No. 10,460,767, "Base Member Including Information Mark and Insulating Coating Layer, and Disk Drive Apparatus Including the Same", issued October 29, 2019 (Compl. ¶49).
  • Technology Synopsis: This patent addresses the need for better quality control in the die-casting process for HDD base members (Compl. ¶50). The solution is a base member that includes an "information mark" containing casting process data. This mark is placed on the base member and then covered by an "insulating coating layer," allowing for improved traceability to identify and correct manufacturing issues, thereby improving quality and yield (Compl. ¶50).
  • Asserted Claims: Claim 1 (Compl. ¶36).
  • Accused Features: The base member of the Seagate 16TB IronWolf Pro HDD is accused of infringing. It allegedly includes a base body made from cast material that has an information mark with casting data located on its surface, with an insulating coating layer covering the mark (Compl. ¶150-152).

III. The Accused Instrumentality

Product Identification

The complaint names specific Seagate-branded HDDs: the Seagate 2TB BarraCuda ST2000LM015 (accused of infringing the ’017 patent) and the Seagate 16TB IronWolf Pro ST16000NE000 (accused of infringing the ’239, ’528, ’775, and ’767 patents). The allegations extend to all "reasonably similar Seagate HDD products" (Compl. ¶24, ¶27, ¶30, ¶33, ¶36).

Functionality and Market Context

The accused products are hard disk drives that store data on rotating disks. The complaint alleges they contain spindle motors, sourced from MinebeaMitsumi Inc., which rotate the disks at high speeds, such as 5,400 RPM for the BarraCuda drive and 7,200 RPM for the IronWolf Pro drive (Compl. ¶53-54, ¶74-75). The complaint alleges the IronWolf Pro is a high-capacity drive sealed with helium gas to improve performance (Compl. ¶149). These drives are marketed for use in a wide range of devices, including laptops, desktop PCs, and network-attached storage (NAS) systems for business applications (Compl. ¶66, ¶94). The complaint includes photographs of the product labels, which identify Defendant Seagate Technology LLC as the manufacturer (Compl. p. 3).

IV. Analysis of Infringement Allegations

U.S. Patent No. 8,737,017 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a stator that includes a stator core and a plurality of coils mounted to the stator core and is disposed above the base unit The accused Seagate 2TB BarraCuda drive incorporates a spindle motor with a stator, stator core, and coils positioned above a base unit. A cross-sectional diagram illustrates this arrangement (Compl. p. 17). ¶57 col. 2:38-41
a covered cylindrical rotor hub that includes a cover portion positioned above the stator and a side wall portion extending downward from an outer edge of the cover portion The spindle motor allegedly has a covered cylindrical rotor hub with a cover portion and a side wall portion as claimed. ¶58 col. 2:42-46
a rotor magnet that is positioned outside the stator in a radial direction thereof and is fixed to an inner circumferential surface of the side wall portion of the rotor hub A rotor magnet is allegedly positioned radially outside the stator and fixed to the inner surface of the rotor hub’s side wall. ¶59 col. 2:47-51
a height of the stator core in an axial direction is about 50% or more and about 70% or less than a height of the stator The complaint alleges the height of the stator core in the accused product's motor is about 63% of the stator's height. ¶61 col. 2:58-61
a torque constant Kt of torque generated between the stator and the rotor magnet is about 4 mN·m/A or more and about 6 mN·m/A or less The complaint alleges the torque constant Kt of the accused product's motor is about 5.4 mN·m/A. ¶62 col. 2:62-65
a motor constant Km is about 2 mN·m/(Α·√Ω) or more and about 4 mN·m/(Α·√Ω) or less The complaint alleges the motor constant Km of the accused product's motor is about 2.8 mN·m/(A·√Ω). ¶63 col. 2:65-67
  • Identified Points of Contention:
    • Scope Questions: The infringement analysis for the ’017 patent may center on the construction of the term "about" as it applies to the three quantitative limitations for stator core height, torque constant, and motor constant. The dispute will be whether the specific values alleged for the accused product—63%, 5.4 mN·m/A, and 2.8 mN·m/(A·√Ω)—fall within the claimed ranges when modified by "about."
    • Technical Questions: A key factual question will be what evidence the complaint or subsequent discovery provides to substantiate the specific numerical performance values alleged for the accused motor. The basis for these "on information and belief" allegations will be a central point of contention.

U.S. Patent No. 9,742,239 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a base portion made of a metal, and including an upper surface, a lower surface, and a base portion through hole passing therethrough... The accused Seagate 16TB IronWolf Pro drive allegedly incorporates a spindle motor with a metal base portion containing a through-hole. Photographs show the exterior and interior of the drive, identifying the through-hole (Compl. p. 24-25). ¶79 col. 7:2-5
the coils include a lead wire drawn out from above the upper surface downwardly from the lower surface through the base portion through hole The spindle motor's coils allegedly include a lead wire that is routed through the base portion's through-hole. ¶85 col. 8:15-18
an insulation sheet portion The spindle motor allegedly incorporates an insulation sheet portion. A micrograph provided in the complaint shows a cross-section of the through-hole with a feature labeled "Insulation Sheet Portion" (Compl. p. 26). ¶82 col. 7:16-17
a first sealant The spindle motor allegedly contains a "first sealant" material within the through-hole. ¶83 col. 7:17
a second sealant The spindle motor allegedly contains a "second sealant" material that covers the through-hole. ¶84 col. 7:18
the first sealant has a coefficient of linear expansion greater than a coefficient of linear expansion of the base portion and smaller than a coefficient of linear expansion of the second sealant The complaint alleges specific values for the coefficients of linear expansion for the first sealant (approx. 3×10⁻⁵/°C), the second sealant (approx. 6×10⁻⁵/°C), and the base portion (approx. 2×10⁻⁵/°C) that satisfy this limitation. ¶91 col. 8:43-47
  • Identified Points of Contention:
    • Technical Questions: The infringement analysis will likely focus on the factual basis for the alleged material properties. A critical question is what evidence exists to prove that the two materials used in the accused product are distinct "first" and "second" sealants and that they possess the specific coefficients of linear expansion alleged in the complaint (Compl. ¶91).
    • Scope Questions: A dispute may arise over whether the structure identified in the complaint's micrograph (Compl. p. 26) constitutes an "insulation sheet portion," a "first sealant," and a "second sealant" as those terms are defined and used within the patent, or if they are simply undifferentiated potting compounds or standard features of a circuit board assembly.

V. Key Claim Terms for Construction

U.S. Patent No. 8,737,017

  • The Term: "about"
  • Context and Importance: This term qualifies all three of the key quantitative limitations in claim 1 related to the motor's physical and performance characteristics (stator height ratio, Kt, and Km). Its construction will determine whether the numerical values alleged for the accused product literally infringe the claimed ranges. Practitioners may focus on this term because the complaint alleges values that are inside the patent's stated numerical bounds but not identical to them.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification's use of phrases like "for example" when discussing specific values could suggest that the numbers are not meant to be rigid limits, supporting a construction of "about" that allows for reasonable technical variance (’017 Patent, col. 2:58-67).
    • Evidence for a Narrower Interpretation: The patent contains numerous graphs (Figs. 6-19) and detailed calculations that correlate specific physical dimensions to specific performance outcomes. A party could argue that this high degree of technical specificity implies that "about" should be construed narrowly to mean only very minor deviations from the stated values.

U.S. Patent No. 9,742,239

  • The Term: "insulation sheet portion"
  • Context and Importance: The existence of a distinct "insulation sheet portion" is a predicate for several other claim limitations, including the requirements that it covers the through-hole and contacts the lead wire. The case may turn on whether the accused structure, identified in a micrograph (Compl. p. 26), meets the definition of this term.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim requires only that it be an "insulation sheet portion" that is "provided on the lower surface" and "covers at least a portion of the base portion through hole" (’239 Patent, cl. 1). A party might argue that any sheet-like insulating material meeting these functional and locational requirements qualifies, regardless of its origin.
    • Evidence for a Narrower Interpretation: The specification repeatedly describes the insulation sheet portion (52) as a feature of the circuit board (50) itself (’239 Patent, FIG. 4; col. 7:51-53). A party could argue that the term should be limited to an insulating layer that is integral to a flexible circuit board assembly, rather than any separate piece of insulating material.

VI. Other Allegations

  • Indirect Infringement: For all five asserted patents, the complaint alleges both induced and contributory infringement. Inducement is based on allegations that Defendants sell the accused HDDs with knowledge of the patents (at least as of the complaint's filing) and provide documentation and marketing that encourages customers to use the drives in an infringing manner (e.g., in NAS or PC systems) (Compl. ¶66, ¶94). Contributory infringement is based on allegations that the accused HDDs are not staple articles of commerce and are especially made or adapted for use in a manner that infringes the patents (Compl. ¶67, ¶95).
  • Willful Infringement: The complaint does not contain allegations of pre-suit knowledge of the patents. However, it establishes a basis for post-suit willful infringement by stating that Defendants are on notice of the patents "since at least as early as the service of this Complaint" and that any continued infringement would be with knowledge of the patents and of the infringement (Compl. ¶65, ¶93).

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

  • A core issue will be one of quantitative scope: can the term "about," as used in the ’017 patent to define specific ranges for motor performance constants, be construed to encompass the precise numerical values alleged for the accused products, and what factual evidence will support those allegations?
  • A key evidentiary question will be one of material science: does discovery support the complaint's highly specific allegations regarding the distinct material compositions and coefficients of linear expansion for the "first sealant" and "second sealant" required by the ’239 patent, or will the evidence show a single, undifferentiated potting material?
  • A central dispute will likely be one of structural definition: do the components and manufacturing features identified in the accused HDDs—such as the "insulation sheet portion" (’239, ’528 Patents), the "impregnant" on a "worked surface" (’775 Patent), and the "information mark" (’767 Patent)—correspond to the specific structures claimed in the patents, or are they conventional features that fall outside the claimed inventions?