DCT
1:18-cv-00396
Seong v. Bedra Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Ki Chul Seong (South Korea) and Opecmade, Inc. (Republic of Korea)
- Defendant: Bedra, Inc. (Delaware), Berkenhoff GmbH (Germany), and Ningbo Bode High-Tech Co., Ltd. (China)
- Plaintiff’s Counsel: Marshall, Gerstein & Borun LLP
- Case Identification: 1:18-cv-00396, N.D. Ill., 06/14/2021
- Venue Allegations: Venue is alleged to be proper for Bedra, Inc. based on its consent to jurisdiction. For the foreign defendants, Berkenhoff and Ningbo, venue is asserted on the basis that foreign defendants may be sued in any judicial district. The complaint further alleges that Berkenhoff purposefully availed itself of the district by selling and importing products into Illinois.
- Core Dispute: Plaintiff alleges that Defendants’ electrical discharge machining (EDM) wires infringe three patents related to porous electrode wires that feature a multi-layer structure with a cracked surface to improve performance.
- Technical Context: The technology concerns specialized electrode wires for wire electrical discharge machining (EDM), a high-precision manufacturing process used to cut conductive materials that are otherwise difficult to machine.
- Key Procedural History: The asserted patents have previously been subject to inter partes review (IPR) proceedings. U.S. Patent Nos. 6,306,523 and 6,482,535 had their challenged claims confirmed as patentable. U.S. Patent No. 6,492,036 had several claims cancelled, including independent claim 1, narrowing its enforceable scope. The complaint also notes prior litigation between Defendant Berkenhoff and Plaintiff Opecmade.
Case Timeline
| Date | Event |
|---|---|
| 1997-07-30 | Earliest Priority Date for ’523, ’535, and ’036 Patents |
| 2001-10-23 | '523 Patent Issued |
| 2002-11-19 | '535 Patent Issued |
| 2002-12-10 | '036 Patent Issued |
| 2012-01-01 | Alleged date by which Defendants knew of the Seong patents |
| 2015-01-01 | China Powerway Group allegedly acquires Berkenhoff |
| 2017-08-15 | Date of SEM analysis shown in complaint |
| 2021-06-14 | Second Amended Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 6,306,523 - Method of manufacturing porous electrode wire for electric discharge machining and structure of the electrode wire (Issued Oct. 23, 2001)
The Invention Explained
- Problem Addressed: The patent addresses the challenge of increasing the machining speed of EDM wires without making them too brittle for the manufacturing process. Prior art methods, such as increasing the zinc content in brass wires, improved performance but compromised the wire's mechanical properties, making it difficult to draw into a fine wire ('523 Patent, col. 2:10-15).
- The Patented Solution: The invention describes a method to create a porous wire structure that enhances performance. The method involves passing a copper or brass core wire through a molten bath of a second metal (like zinc) in a process called hot-dip galvanizing. This forms a hard, brittle "alloy layer" via diffusion between the core and an outer "coating layer" of the second metal ('523 Patent, col. 3:41-54). When this multi-layer wire is subsequently drawn to a smaller diameter, the hard alloy layer cracks, creating a porous surface that increases the surface area for cooling and improves debris removal ('523 Patent, col. 4:10-18).
- Technical Importance: This manufacturing technique provided a way to create a high-performance EDM wire with improved cutting speed and flushability, key metrics in precision manufacturing, without requiring additional complex process steps ('523 Patent, Abstract).
Key Claims at a Glance
- The complaint asserts independent claim 14 (Compl. ¶28).
- Essential elements of claim 14:
- An electrode wire comprising: a core wire of a first metal including copper; an alloy layer on the core wire; and a coating layer on the alloy layer made of a second metal with a lower vaporization temperature.
- The alloy layer is formed by a diffusion reaction and has a higher hardness and lower elongation than the core or coating layer.
- Cracks are formed in the alloy layer and the coating layer, with a direction perpendicular to the longitudinal direction of the wire.
- The complaint does not explicitly reserve the right to assert dependent claims.
U.S. Patent No. 6,482,535 - Porous electrode wire for use in electrical discharge machining and method of manufacturing the same (Issued Nov. 19, 2002)
The Invention Explained
- Problem Addressed: As with the '523 patent, the invention seeks to overcome the performance limitations of conventional EDM wires by improving machining speed and accuracy ('535 Patent, col. 2:15-34).
- The Patented Solution: This patent claims the structure of the resulting electrode wire itself, but in a simplified two-part form compared to the '523 patent. The claimed wire consists of a copper-containing core and an "alloy layer" formed on it via a diffusion reaction with a second metal ('535 Patent, col. 4:3-9). The key feature is that this alloy layer possesses a "crack structure on its surface," which creates the desired porosity for enhanced cooling and performance during EDM ('535 Patent, Abstract).
- Technical Importance: The invention claims a specific product-by-process structure for an EDM wire that achieves improved performance through a cracked, porous surface, which increases cooling ability and flushability ('535 Patent, Abstract).
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶42).
- Essential elements of claim 1:
- An electrode wire comprising: a core wire made of a first metal including copper.
- An alloy layer formed on the core wire.
- The alloy layer is formed by a diffusing reaction between the first metal and a second metal.
- The alloy layer has a crack structure on its surface.
- The complaint does not explicitly reserve the right to assert dependent claims.
U.S. Patent No. 6,492,036 - Porous electrode wire for use in electrical discharge machining and method of manufacturing the same (Issued December 10, 2002)
- Technology Synopsis: This patent, part of the same family, also describes an electrode wire designed for improved EDM performance ('036 Patent, Abstract). The claimed wire comprises a copper-containing core, an intermediate alloy layer formed by diffusion, and an outer coating layer made of the second metal. The invention specifies that cracks are formed in both the alloy layer and the coating layer during the wire drawing process, creating the performance-enhancing porous surface ('036 Patent, col. 4:10-20).
- Asserted Claims: The complaint asserts at least claim 2, a dependent claim (Compl. ¶56). Independent claim 1 was cancelled during a prior IPR proceeding.
- Accused Features: The accused products are alleged to infringe by having a structure that includes a copper/brass core, an alloy layer, and a coating layer, with cracks formed in these layers during the drawing process (Compl. ¶58).
III. The Accused Instrumentality
Product Identification
- The accused instrumentalities are a range of "bedra" brand EDM wires, including "bedra HyperCut," "bedra Broncocut®," "bedra Topas® Plus," "bedra Boline," and "bedra Gamma," among others (Compl. ¶28, ¶42, ¶56).
Functionality and Market Context
- The complaint alleges that the accused wires consist of a core material made of copper or brass, an alloy layer formed on the core via a diffusion reaction between the core's copper and a zinc coating, and a cracked surface structure (Compl. ¶24, ¶26).
- The complaint provides a scanning electron microscope (SEM) image showing the cracked surface of a "BEDRA TYPE H 002" wire, identified as being from the "Topas® Plus" product line (Compl. ¶24). A similar SEM image is provided for Ningbo's "Gamma" product, also showing a cracked surface structure (Compl. ¶26).
- The complaint positions Defendant Berkenhoff as "one of the largest manufacturers of EDM wires in the world," suggesting the commercial significance of the accused products (Compl. ¶24).
IV. Analysis of Infringement Allegations
'523 Patent Infringement Allegations
| Claim Element (from Independent Claim 14) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a core wire made of first metal including copper | The accused wires are alleged to contain a "copper or brass core" (Compl. ¶24). The "Topas® Plus Type H" is alleged to be composed of a form of brass (Compl. ¶30). | ¶24, ¶30 | col. 7:56-57 |
| an alloy layer formed on the core wire | The accused wires are alleged to have "an alloy layer formed on the core" (Compl. ¶24). The "Topas® Plus Type H" is alleged to have an alloy layer of approximately 50% copper and 50% zinc (Compl. ¶30). | ¶24, ¶30 | col. 7:12-13 |
| a coating layer on the alloy layer made of a second metal having vaporization temperature lower than the first metal | The "Topas® Plus Type H" product is alleged to have "a coating layer that contains about 65% copper and about 35% zinc" (Compl. ¶30). Zinc has a lower vaporization temperature than copper. | ¶30 | col. 7:17-19 |
| wherein the alloy layer is formed by diffusion reaction between the first metal and the second metal | The alloy layer in the accused wires is alleged to be "created by a diffusion reaction between the copper in the core and zinc" (Compl. ¶24). | ¶24 | col. 7:22-24 |
| and has a higher hardness and lower elongation than the core wire or the coating layer | The complaint does not provide sufficient detail for analysis of this element. It does not explicitly allege the relative hardness or elongation properties, but these properties are the patent's stated cause for the alleged cracking. | N/A | col. 7:25-27 |
| and wherein cracks are formed in the alloy layer and the coating layer having direction perpendicular to the longitudinal direction... | The complaint alleges that the "Topas® Plus Type H" product "contains cracks in the coating and alloy layers" (Compl. ¶30). The provided SEM image for this product line shows surface cracks that are generally perpendicular to the wire's axis (Compl. ¶24). The complaint also includes SEM images allegedly showing cracks in the "Broncocut® Type X" product's alloy layer (Compl. ¶25). | ¶24, ¶25, ¶30 | col. 8:27-33 |
'535 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a core wire made of first metal including copper | The accused wires are alleged to contain a "core material made of either copper or brass" (Compl. ¶24). | ¶24, ¶44 | col. 8:1-2 |
| an alloy layer formed on the core wire | The accused wires are alleged to have "an alloy layer formed on the core" (Compl. ¶24). The "Topas® Plus" and "Gamma" products are specifically alleged to have this layer (Compl. ¶44). | ¶24, ¶44 | col. 8:3-4 |
| wherein the alloy layer is formed by a diffusing reaction between the first metal and a second metal | The accused wires' alloy layer is alleged to be "created by a diffusion reaction between the copper in the core and zinc" (Compl. ¶24). | ¶24 | col. 8:4-6 |
| and the alloy layer has a crack structure on its surface | The accused wires are alleged to have a "cracked structure on the surface of the wire" (Compl. ¶24). This allegation is supported by SEM images of the Topas® Plus and Gamma products (Compl. ¶24, ¶26). | ¶24, ¶26, ¶44 | col. 8:6-8 |
Identified Points of Contention
- Technical Questions: A primary factual dispute may center on the physical structure of the accused wires. While the complaint provides surface-level SEM images, a key question is whether Plaintiffs can produce cross-sectional evidence to prove the existence, composition, and properties of the distinct "alloy layer" and "coating layer" as required by the claims of the '523 and '036 patents.
- Scope Questions: The case for the '523 patent requires proving three distinct layers (core, alloy, coating). The case for the '535 patent requires only two (core, alloy). A point of contention may be whether the accused products, such as the Topas® Plus wire, actually have a separate "coating layer" distinct from the "alloy layer," or if they more closely resemble the two-layer structure of the '535 patent.
- Scope Questions: For the '523 patent, a potential dispute exists over whether the accused alloy layer meets the functional limitation of having "higher hardness and lower elongation" than the other layers. The complaint infers this by alleging the resultant cracks, but does not directly allege the property itself, which could create an area for defensive arguments.
V. Key Claim Terms for Construction
For the '523 and '535 Patents
The Term: "alloy layer"
Context and Importance: This term appears in the independent claims of all asserted patents and is foundational to the infringement case. Its construction will determine the necessary physical and chemical characteristics of the intermediate layer. Practitioners may focus on this term because the patents define it as being formed by a "diffusion reaction" and, in the '523 patent, as having specific relative hardness and elongation properties.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification's general description of forming the layer "by diffusion reaction of the brass of the core wire and zinc of the coating layer" could support a reading that covers any zone of intermixing between the core and coating metals ('523 Patent, col. 5:1-3).
- Evidence for a Narrower Interpretation: The figures and detailed description present the alloy layer (22) as a structurally distinct layer situated between the core (21) and the coating layer (23) ('523 Patent, Fig. 3b). Claim 14 of the '523 patent further requires it to have "higher hardness and lower elongation," suggesting the term requires not just a specific formation process but also specific, measurable physical properties.
The Term: "crack structure" / "cracks ... having direction perpendicular to the longitudinal direction"
Context and Importance: The presence of cracks is the key feature that allegedly creates the porous, high-performance surface. The definition of what constitutes a "crack" and how "perpendicular" it must be will be critical to determining infringement.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent figures themselves (e.g., '523 Patent, Fig. 4a) and the SEM images in the complaint (Compl. ¶24) depict cracks that are generally, but not perfectly, perpendicular. This may support a construction that does not require strict geometric orthogonality.
- Evidence for a Narrower Interpretation: The specification explicitly links the formation of cracks to the "drawing step" acting on the "hard alloy layer" ('523 Patent, col.5:16-22). A defendant could argue this requires proof that the cracks arise from this specific mechanism, not from other manufacturing artifacts, and that they must form a coherent "structure" rather than being random surface imperfections.
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement by asserting that Defendants intended for their customers to use the accused EDM wires in infringing EDM processes (Compl. ¶32, ¶46, ¶60). This intent is supported by allegations that Defendants offered for sale and sold the wires specifically for these known uses (Compl. ¶34, ¶48, ¶62).
- Willful Infringement: Willfulness is alleged based on pre-suit knowledge of the patents. The complaint claims Defendants knew of the patents "by 2012" because they had access to Plaintiffs' patent-marked products (Compl. ¶33, ¶47, ¶61). The complaint further alleges that Defendants "copied the cracked structure surface improvement from one of more of the Seong patents," which, if proven, would strongly support a finding of willfulness (Compl. ¶40, ¶54, ¶68).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central evidentiary question will be one of structural verification: can Plaintiffs prove, through metallurgical analysis, that the accused wires possess the specific multi-layer structure recited in the claims—particularly the distinct "alloy layer" formed by diffusion and, for the '523 and '036 patents, an outer "coating layer"—as opposed to a more graded or undifferentiated composition?
- A key legal question will concern definitional scope: how will the court construe the term "crack structure"? Will any surface fissure suffice, or must Plaintiffs demonstrate that the cracks are the direct result of the specific manufacturing process (i.e., drawing a hard, brittle alloy layer) and possess the structural characteristics described in the patents?
- A third issue will involve the impact of prior administrative review: given that the asserted claims survived inter partes review challenges (albeit with the '036 patent's scope being narrowed), how will this procedural history affect the court's analysis of the patents' validity and the construction of the surviving claims?