DCT

3:24-cv-06555

Godo Kaisha IP Bridge 1 v. Western Digital Tech Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:24-cv-00342, D. Del., 07/08/2024
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because both Defendants are incorporated in the state.
  • Core Dispute: Plaintiff alleges that Defendants’ hard disk drive products infringe nine U.S. patents related to the structure and manufacture of high-performance magnetic tunnel junction (MTJ) devices used in read/write heads.
  • Technical Context: The technology involves using crystalline magnesium oxide (MgO) as a "tunnel barrier" layer in magnetoresistive devices, an innovation that significantly increased data storage density and performance in hard disk drives (HDDs).
  • Key Procedural History: Plaintiff acquired the asserted patent portfolio in 2021. The complaint alleges that Defendant Western Digital Technologies, Inc. became aware of the lead asserted patent (U.S. Patent No. 7,884,403) no later than September 2022, when its published application was cited as relevant prior art during the prosecution of Defendants' own patent application, a fact central to the allegations of willful infringement.

Case Timeline

Date Event
2004-03-12 Priority Date for all Asserted Patents
2011-02-08 U.S. Patent No. 7,884,403 Issues
2012-11-27 U.S. Patent No. 8,319,263 Issues
2013-03-26 U.S. Patent No. 8,405,134 Issues
2015-09-01 U.S. Patent No. 9,123,463 Issues
2017-03-28 U.S. Patent No. 9,608,198 Issues
2018-03-01 Alleged Infringement Start Date (approx.)
2019-07-30 U.S. Patent No. 10,367,138 Issues
2020-06-09 U.S. Patent No. 10,680,167 Issues
2022-09-01 Search Report citing ’403 Patent issued for WDT's PCT Application (approx.)
2023-08-22 U.S. Patent No. 11,737,372 Issues
2024-04-23 U.S. Patent No. 11,968,909 Issues
2024-07-08 First Amended Complaint Filed

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

U.S. Patent No. 7,884,403 - "Magnetic Tunnel Junction Device and Memory Device Including the Same"

The Invention Explained

  • Problem Addressed: The patent’s background describes that conventional magnetic tunnel junction (MTJ) devices, which are central to MRAM and HDD read heads, used an amorphous aluminum-oxide (Al-O) tunnel barrier. These devices exhibited a relatively low magnetoresistance (MR) ratio (around 70%), which limited output voltage and hampered the development of higher-density memory devices (’403 Patent, col. 1:40-56).
  • The Patented Solution: The invention replaces the amorphous barrier with a highly-ordered, single-crystalline or poly-crystalline magnesium oxide (MgO) layer. This structure suppresses electron scattering and enables "coherent tunneling," which dramatically increases the MR ratio. (’403 Patent, col. 5:26-35, Fig. 1(B)). The patent also teaches that intentionally creating "oxygen vacancy defects" in the MgO layer can lower its potential barrier height, thereby increasing the tunneling current and further improving device performance (’403 Patent, col. 6:52-61).
  • Technical Importance: This approach of using a crystalline MgO barrier produced a "giant MR ratio" that significantly increased the sensitivity and output signal of magnetoresistive devices, enabling a new generation of higher-density data storage. (Compl. ¶¶10, 17-18).

Key Claims at a Glance

  • The complaint asserts at least independent claim 5. (Compl. ¶50).
  • Essential elements of claim 5:
    • A first ferromagnetic material layer of a BCC structure;
    • A second ferromagnetic material layer of the BCC structure;
    • A magnesium oxide layer located between the first and second layers;
    • Wherein the magnesium oxide is a single-crystalline (001) or poly-crystalline layer in which the (001) crystal plane is preferentially oriented;
    • Wherein the magnesium oxide has oxygen vacancy defects; and
    • Wherein the magnesium oxide has a tunnel barrier height in a range of 0.2 to 0.5 eV.
  • The complaint does not explicitly reserve the right to assert dependent claims for the ’403 patent.

U.S. Patent No. 8,319,263 - "Magnetic Tunnel Junction Device"

The Invention Explained

  • Problem Addressed: As a continuation of the application leading to the ’403 patent, the ’263 patent addresses the same technical problem: the limited MR ratio and output voltage of prior art MTJ devices that used amorphous tunnel barriers. (’263 Patent, col. 1:40-56).
  • The Patented Solution: The patent describes a similar MTJ structure with a crystalline MgO tunnel barrier but focuses the claims on a structure where at least one of the ferromagnetic electrodes is an amorphous alloy (such as CoFeB) that becomes crystallized during the manufacturing process. (’263 Patent, col. 9:1-14, Fig. 11). This manufacturing method allows for the formation of a highly ordered final device structure, achieving the desired high MR ratio.
  • Technical Importance: This refinement of the MTJ structure, using crystallizable amorphous alloys with an MgO barrier, provided a practical manufacturing path to achieve the high-performance characteristics needed for next-generation data storage devices. (Compl. ¶¶17-18).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1. (Compl. ¶87).
  • Essential elements of claim 1:
    • A first ferromagnetic material layer deposited on a substrate;
    • A second ferromagnetic material layer;
    • A tunnel barrier layer located between the first and second layers;
    • Wherein the tunnel barrier layer comprises a single-crystalline or poly-crystalline magnesium oxide in which the (001) crystal plane is preferentially oriented; and
    • Wherein at least the first ferromagnetic material layer is crystallized and comprises CoFeB alloy.
  • The complaint does not explicitly reserve the right to assert dependent claims for the ’263 Patent.

U.S. Patent No. 11,737,372 - "Method of Manufacturing a Magnetoresistive Random Access Memory (MRAM)"

  • Technology Synopsis: This patent, part of the same family, claims a method of manufacturing an MTJ device. The method involves forming amorphous CoFeB layers around a magnesium oxide (MgO) layer and then performing an annealing step to crystallize the CoFeB layers and the MgO layer. (’372 Patent, Abstract; col. 10:55-65).
  • Asserted Claims: At least claim 1 is asserted. (Compl. ¶106).
  • Accused Features: The methods used by Defendants to manufacture the read/write heads in their HDD products. (Compl. ¶107).

U.S. Patent No. 11,968,909 - "Method of Manufacturing a Magnetoresistive Random Access Memory (MRAM)"

  • Technology Synopsis: This patent claims a magnetoresistive device structure comprising a multi-layer stack. The claims focus on a crystalline MgO tunnel barrier with oxygen vacancy defects, sandwiched between first and second ferromagnetic material layers. (’909 Patent, col. 10:1-11).
  • Asserted Claims: At least claim 1 is asserted. (Compl. ¶125).
  • Accused Features: The MTJ structures within the read/write heads of Defendants' HDD products. (Compl. ¶126).

U.S. Patent No. 10,367,138 - "Magnetic Tunnel Junction Device"

  • Technology Synopsis: This patent claims an MTJ device with a poly-crystalline MgO barrier layer disposed between two ferromagnetic material layers that include Co, Fe, and B. The claims require the ferromagnetic layers to be entirely crystallized and the MgO layer to have a value 'x' in MgOx between 0 and 1. (’138 Patent, col. 9:55-67).
  • Asserted Claims: At least claim 12 is asserted. (Compl. ¶144).
  • Accused Features: The MTJ structures within the read/write heads of Defendants' HDD products. (Compl. ¶145).

U.S. Patent No. 9,608,198 - "Magnetic Tunnel Junction Device"

  • Technology Synopsis: This patent claims a tunnel barrier layer disposed on a ferromagnetic material layer, where the barrier comprises a poly-crystalline magnesium oxide layer. A key limitation is that the ferromagnetic material layer comprises a CoFeB alloy that is at least partially crystallized. (’198 Patent, col. 10:1-12).
  • Asserted Claims: At least claim 1 is asserted. (Compl. ¶163).
  • Accused Features: The MTJ structures within the read/write heads of Defendants' HDD products. (Compl. ¶164).

U.S. Patent No. 9,123,463 - "Magnetic Tunnel Junction Device"

  • Technology Synopsis: This patent claims a tunnel barrier layer disposed on a ferromagnetic material layer. The claims require the ferromagnetic material to be a crystallized CoFeB alloy and the tunnel barrier to be a poly-crystalline MgO layer with a specific barrier height, which is determined by fitting current-voltage (J-V) characteristics to the Simmons' formula. (’463 Patent, col. 10:1-24).
  • Asserted Claims: At least claim 1 is asserted. (Compl. ¶182).
  • Accused Features: The MTJ structures within the read/write heads of Defendants' HDD products. (Compl. ¶183).

U.S. Patent No. 10,680,167 - "Magnetic Tunnel Junction Device"

  • Technology Synopsis: This patent claims a method of manufacturing an MTJ device. The method involves forming amorphous CoFeB layers on either side of an amorphous MgO layer, and then annealing the structure to crystallize the layers. (’167 Patent, col. 10:1-13).
  • Asserted Claims: At least claim 1 is asserted. (Compl. ¶201).
  • Accused Features: The methods used by Defendants to manufacture the read/write heads in their HDD products. (Compl. ¶202).

U.S. Patent No. 8,405,134 - "Magnetic Tunnel Junction Device"

  • Technology Synopsis: This patent claims a magnetoresistive device with a crystalline MgO tunnel barrier. The claims require the first and second ferromagnetic layers to have a Body-Centered Cubic (BCC) structure and the barrier height to be in a specific range of 0.2 to 0.5 eV. (’134 Patent, col. 10:5-17).
  • Asserted Claims: At least claim 1 is asserted. (Compl. ¶204).
  • Accused Features: The MTJ structures within the read/write heads of Defendants' HDD products. (Compl. ¶205).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are read/write heads for hard disk drives ("HDDs") and the HDDs that incorporate them, including a wide range of product lines sold under the WD, Ultrastar, HGST, My Passport, SanDisk Professional, G-Technology, and other brands. (Compl. ¶¶41-42).

Functionality and Market Context

The complaint alleges that these HDDs function by reading and writing data using read heads that employ the Tunnel Magnetoresistance (TMR) effect. (Compl. ¶¶15-16). This effect relies on an MTJ structure where the electrical resistance changes based on the magnetic alignment of two ferromagnetic layers separated by a thin insulating "tunnel barrier." (Compl. ¶15). A diagram in the complaint illustrates how a parallel magnetic alignment results in low resistance, while an antiparallel alignment results in high resistance, allowing for the detection of magnetic data bits. (Compl. p. 6). The complaint positions Defendants as a major manufacturer of HDDs whose products incorporate these allegedly infringing MTJ structures. (Compl. ¶¶21-22, 41).

IV. Analysis of Infringement Allegations

The complaint alleges that Defendants' accused HDD products meet every limitation of the asserted claims but incorporates the detailed infringement analysis by reference to Exhibits AA through II, which are not attached to the publicly filed complaint. (Compl. ¶¶ 44, 51, 88). Therefore, a detailed claim chart cannot be constructed from the complaint's text. The general infringement theory is that the read/write heads within Defendants’ HDDs contain MTJ structures comprising the specific layered compositions and physical properties recited in the asserted claims, including a crystalline MgO tunnel barrier situated between ferromagnetic layers. (Compl. ¶¶14, 18, 41).

  • Identified Points of Contention:
    • Technical Questions: A primary point of contention for product claims like claim 5 of the ’403 Patent will likely be evidentiary. Proving infringement will require demonstrating, through potentially destructive testing and expert analysis of nanoscale device structures, that the accused products possess the specific material properties claimed. Questions for the court may include what evidence is sufficient to establish the presence of "oxygen vacancy defects" and to prove that the "tunnel barrier height" falls within the claimed range of 0.2 to 0.5 eV.
    • Scope Questions: For claims like claim 1 of the ’263 Patent, a central dispute may be one of claim scope. The term "crystallized" will be critical, as the accused devices may be manufactured using an initially amorphous CoFeB alloy. The key question for claim construction will be what degree of atomic ordering is required to meet the "crystallized" limitation, raising the possibility of disputes over whether the state achieved during Defendants' manufacturing process falls within the scope of the claim.

V. Key Claim Terms for Construction

  • The Term: "oxygen vacancy defects" (from claim 5 of the ’403 Patent)

  • Context and Importance: This term defines a specific physical property of the claimed MgO tunnel barrier. Its construction is critical because the presence or absence of these specific defects could be dispositive of infringement. Practitioners may focus on this term because Defendants could argue their MgO layers are stoichiometric or that any naturally occurring imperfections do not rise to the level of the specific "defects" contemplated by the patent.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification suggests these defects can be an inherent result of the deposition process, stating that the separation of oxygen from MgO during deposition creates "the possibility that there are oxygen vacancy defects." (’403 Patent, col. 7:1-6). This may support a construction where such defects are a natural and expected outcome of the disclosed manufacturing method.
    • Evidence for a Narrower Interpretation: The specification also quantifies the composition as MgOx, where "0.98<x<1, and more preferably 0.99<x<1." (’403 Patent, col. 7:22-24). This language may support a narrower construction requiring a specific, measurable stoichiometric deficiency to qualify as having the claimed "defects."

  • The Term: "crystallized" (from claim 1 of the ’263 Patent)

  • Context and Importance: This term describes the required final state of the CoFeB alloy layer. Its meaning is central to the infringement analysis because the manufacturing process may begin with an amorphous CoFeB layer that is later subjected to annealing. The dispute will likely center on whether the resulting structure is sufficiently ordered to be considered "crystallized."

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification states that an annealing process "might cause the amorphous magnetic alloy in the electrode layers to be partially or entirely crystallized," but that this "would not lead to a significant deterioration of the MR ratio." (’263 Patent, col. 9:22-26). This language may support a construction where even partial crystallization meets the claim limitation.
    • Evidence for a Narrower Interpretation: The patent repeatedly contrasts the invention's ordered structure with prior art amorphous barriers to achieve "coherent tunneling." (’263 Patent, col. 5:26-35). A defendant may argue that "crystallized" must be construed to mean a degree of crystalline order sufficient to enable the functional advantages described in the patent, not merely incidental or partial ordering.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement, stating that Defendants encourage infringement by customers and resellers through marketing materials, user manuals, product documentation, and websites that promote the use of the accused HDDs. (Compl. ¶¶65-66, 92-93). Contributory infringement is also alleged on the basis that the accused products, particularly the read/write heads, have no substantial non-infringing uses and are a material part of the invention. (Compl. ¶¶74-76, 98-100).
  • Willful Infringement: A claim of willful infringement is made against the ’403 patent based on alleged knowledge since at least September 2022. (Compl. ¶78). The complaint alleges that during the prosecution of its own patent application, Defendant WDT received an international search report that identified the published application for the ’403 patent as a "document of 'particular relevance'." (Compl. ¶¶54-56). The complaint provides a screenshot of this search report, which lists the '403 patent's application as the first reference. (Compl. p. 18). It further alleges that WDT submitted this report to the USPTO, providing a screenshot of the Information Disclosure Statement (IDS) form listing the reference. (Compl. p. 19). Plaintiff argues that these actions establish that WDT knew or was willfully blind to the existence and relevance of the ’403 patent. (Compl. ¶¶60-61, 79).

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

  • A central issue will be one of material characterization: can Plaintiff present sufficient evidence, likely from complex and destructive analysis of commercial HDD products, to prove that the nanoscale layers within Defendants' read heads possess the specific physical and electrical properties required by the claims, such as the presence of "oxygen vacancy defects" and a "tunnel barrier height" within the narrow claimed range of 0.2 to 0.5 eV?
  • A key question for damages will be willfulness: given the documentary evidence that Defendants' own patent prosecution process identified the ’403 patent’s application as highly relevant prior art in 2022, did Defendants proceed with objective recklessness by continuing to sell accused products, or will Defendants be able to demonstrate a good-faith belief of non-infringement or invalidity?
  • The case may also turn on a question of definitional scope: can the term "crystallized," as applied to an initially amorphous CoFeB alloy, be construed to cover the specific degree of atomic ordering that results from Defendants' manufacturing and annealing processes, or will there be a fundamental mismatch in structure?