DCT

1:25-cv-00626

Samsung Electronics Co Ltd v. Netlist Inc

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00626, D. Del., 06/09/2025
  • Venue Allegations: Venue is asserted in the District of Delaware on the basis that Defendant Netlist, Inc. is a corporation organized and existing under the laws of the State of Delaware.
  • Core Dispute: Plaintiff Samsung seeks a declaratory judgment that its High Bandwidth Memory (HBM) products do not infringe Defendant Netlist's patent related to stacked memory die architecture.
  • Technical Context: The technology concerns High Bandwidth Memory (HBM), a type of high-performance RAM that vertically stacks memory dies to achieve higher bandwidth and lower power consumption, critical for data centers and artificial intelligence applications.
  • Key Procedural History: The complaint outlines a complex procedural background, including a disputed termination of a 2015 license agreement between the parties that is the subject of separate litigation. It also notes that the patent-in-suit is a continuation of two patents (U.S. Patent Nos. 8,787,060 and 9,318,160) previously asserted by Netlist against Samsung's HBM products in the Eastern District of Texas. While a jury found infringement of those patents, the PTAB subsequently found all claims of both patents unpatentable in inter partes reviews initiated by Samsung; both the jury verdict and the PTAB decisions are currently on appeal. The patent-in-suit was issued subject to a terminal disclaimer over these invalidated patents. Notably, Netlist filed an infringement suit on the patent-in-suit in Texas the day before it formally issued.

Case Timeline

Date Event
2010-11-03 '087 Patent Earliest Priority Date
2015-11-12 Samsung and Netlist enter Joint Development and License Agreement (JDLA)
2020-07-15 Netlist sends letter terminating the JDLA
2021-10-15 Samsung files first declaratory judgment action against Netlist in Delaware
2021-12-20 Netlist files "EDTX I Action" against Samsung on related patents
2022-08-26 Samsung files IPR petitions on the '060 and '160 patents
2024-04-01 PTAB issues Final Written Decisions invalidating all claims of the '060 and '160 patents
2025-05-19 Netlist files infringement suit on the '087 patent in E.D. Tex. (one day before patent issuance)
2025-05-20 U.S. Patent No. 12,308,087 issues
2025-06-09 Samsung files this complaint for declaratory judgment of non-infringement

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

U.S. Patent No. 12,308,087 - "Memory Package Having Stacked Array Dies and Reduced Driver Load"

  • Patent Identification: U.S. Patent No. 12,308,087, issued May 20, 2025.

The Invention Explained

  • Problem Addressed: In memory packages with vertically stacked dies, the electronic "drivers" on the main control die must be powerful enough to send signals through the interconnects to all the dies in the stack. The patent states that as stacks get taller, these drivers must become larger, consuming more physical space on the control die and using more power (’087 Patent, col. 2:26-34).
  • The Patented Solution: The invention proposes splitting the signal paths. Instead of one powerful driver and a single interconnect serving all dies in the stack, the patent describes using multiple, smaller drivers, each connected to a separate interconnect that serves only a subset of the dies. This partitioning scheme is intended to reduce the electrical load on any individual driver, allowing for smaller and more power-efficient driver designs (’087 Patent, Abstract; col. 4:1-15). The complaint reproduces Figure 2 of the ’087 Patent, which schematically illustrates a memory package with a control die and stacked array dies connected by die interconnects (Compl. p. 20).
  • Technical Importance: This approach addresses a fundamental scaling challenge in 3D-stacked memory, suggesting a way to increase memory density and performance without a corresponding penalty in power consumption and control die size (’087 Patent, col. 18:68 - col. 19:14).

Key Claims at a Glance

  • The complaint identifies six independent claims: 1, 9, 13, 20, 23, and 24 (Compl. ¶73).
  • Independent Claim 1, as an example, recites the following essential elements:
    • A DRAM package with "stacked DRAM dies" comprising a "first plurality" and a "second plurality" of dies.
    • "terminals" for receiving command/address (C/A) and data signals.
    • "die interconnects" including C/A and data interconnects, with specific interconnects configured to conduct signals to the first plurality of dies but not the second, and vice-versa.
    • A "control die" coupled between the terminals and the stacked dies.
    • A "first C/A interconnect" that is in electrical communication with the first plurality of DRAM dies and "not in electrical communication with any C/A port on any of the second plurality of DRAM dies."
    • A corresponding limitation for a "second C/A interconnect" and the second plurality of dies.
    • "first unidirectional interconnects" configured to conduct signals from the DRAM dies to the control die, but not the other way.
    • "second unidirectional interconnects" configured to conduct signals from the control die to the DRAM dies, but not the other way.
    • A "control die" that is configured to receive signals via the first unidirectional interconnects and drive signals via the second unidirectional interconnects, but which includes negative limitations that it is not configured to drive via the first set or receive via the second set.
  • The complaint does not explicitly reserve the right to assert dependent claims but implies non-infringement of all claims by stating that the accused products do not infringe claims that depend from the asserted independent claims (Compl. ¶77).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are Samsung’s High Bandwidth Memory (HBM) products, including "any Samsung HBM2, HBM2E, HMB3, HBM3E and newer products (e.g., HBM4)" (Compl. ¶58).

Functionality and Market Context

  • The complaint describes these products as memory modules that utilize stacked-die technology to provide high-density, high-performance memory solutions (Compl. ¶¶ 13, 24, 58).
  • The complaint cites a Netlist regulatory filing stating that "the memory market remains poised for significant growth driven by the industry’s transition to HBM" and that Netlist is "well-positioned to capitalize on this" through its intellectual property, suggesting the products operate in a commercially significant market (Compl. ¶23).

IV. Analysis of Infringement Allegations

Samsung's complaint for declaratory judgment asserts non-infringement. The following table summarizes Samsung's primary non-infringement arguments for representative Claim 1.

’087 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Non-Infringing Functionality Complaint Citation Patent Citation
wherein the die interconnects further include first unidirectional interconnects configured to conduct signals from one or more DRAM dies of the stacked DRAM dies to the control die and not configured to conduct any signal from the control die to any of the stacked DRAM dies; The complaint alleges that Samsung HBM products do not include "unidirectional interconnects" that meet the claim limitations. It states the products do not include through-silicon vias ("TSVs") that satisfy all limitations related to this term. ¶75 col. 24:58-64
wherein the die interconnects further include second unidirectional interconnects configured to conduct signals from the control die to one or more DRAM dies of the stacked DRAM dies and not configured conduct any signal from any of the stacked DRAM dies to the control die; The complaint alleges that Samsung HBM products do not include the "second unidirectional interconnects" as claimed, which must only conduct signals from the control die and not to it. ¶75 col. 25:1-6
wherein the control die is configured to receive signals from one or more DRAM dies... via the first unidirectional interconnects and is not configured to drive any signal... via any of the first unidirectional interconnects... The complaint alleges that the Samsung HBM Products do not include a "control die" that meets the specific positive and negative functional requirements of the claim. ¶76 col. 25:7-13

Identified Points of Contention

  • Scope Questions: A central dispute may concern the proper construction of "unidirectional interconnects." The question for the court will be whether the through-silicon via (TSV) architecture in Samsung's HBM products falls within the scope of this term, which is defined by both what it is configured to do and what it is configured not to do.
  • Technical Questions: A key factual question will be whether the components in Samsung’s HBM products constitute a "control die" that meets the specific functional limitations of the claims. This analysis may focus on the negative limitations—for example, what evidence can be shown to prove a component is "not configured" to perform a certain function as required by the claims.

V. Key Claim Terms for Construction

The Term: "unidirectional interconnects"

  • Context and Importance: This term is central to Samsung's non-infringement argument, as it alleges its HBM products do not contain this feature (Compl. ¶75). The case may hinge on whether the TSV-based architecture in the accused products can be considered "unidirectional" as claimed.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party might argue that any interconnect that is operated in only one direction for a given command (e.g., read or write) is functionally "unidirectional," even if physically capable of bi-directional signal flow. The patent abstract describes a general concept of separating signal paths without rigidly defining the physical structure.
    • Evidence for a Narrower Interpretation: The claim language itself provides a specific functional definition, including a negative limitation: "configured to conduct signals from... to the control die and not configured to conduct any signal from the control die..." (’087 Patent, col. 24:58-64). This language may support an interpretation requiring a structural or hard-wired one-way path, rather than mere operational directionality. The specification also explicitly contrasts bi-directional and unidirectional embodiments, noting that unidirectional systems "may include double the number of die interconnects" ('087 Patent, col. 9:10-16).

The Term: "control die"

  • Context and Importance: Practitioners may focus on this term because Samsung alleges its HBM products lack a "control die" that meets the specific combination of positive and negative limitations recited in the asserted claims (Compl. ¶76).
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the control die in general terms as a "master die" or a "logic layer" (’087 Patent, col. 6:22, col. 6:33-34) and states it can "respond to signals received by the memory package... by sending appropriate control signals to the array dies" (’087 Patent, col. 1:50-53). This could support a broad definition covering various controller architectures.
    • Evidence for a Narrower Interpretation: The claims require the "control die" to perform a highly specific set of functions in relation to the "unidirectional interconnects," including what it is "configured to" do and, critically, what it is "not configured to" do (’087 Patent, col. 25:7-20). A party could argue that this claim language requires a specific architecture that is distinct from the integrated logic within Samsung's HBM products.

VI. Other Allegations

  • Indirect Infringement: The complaint seeks a declaration of non-infringement as to both direct and indirect infringement (Compl. ¶80; Prayer for Relief ¶(a)). However, as a declaratory judgment action filed by the accused infringer, it does not set forth the specific facts Netlist may have alleged in other venues to support knowledge and intent for an indirect infringement claim.
  • Willful Infringement: The complaint does not contain allegations of willful infringement for analysis.

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

  • A core issue will be one of claim construction: can the term "unidirectional interconnects," which is defined by both positive and negative functional limitations, be construed to read on the through-silicon via (TSV) architecture of Samsung's HBM products? The outcome will likely depend on whether the term requires a physically distinct one-way structure or can encompass pathways that are functionally operated in a single direction.
  • A second central issue will be one of evidentiary proof and technical mapping: does the architecture of the accused HBM products include a "control die" that meets the specific configuration recited in the claims? This question may turn on the evidence presented to prove the negative limitations (i.e., that a component is "not configured" to perform a function), which can be a complex factual and technical determination.