DCT
2:23-cv-00420
Nitek Inc v. Photon Wave Co Ltd
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Nitek, Inc. (South Carolina)
- Defendant: Photon Wave Co., Ltd. (Republic of Korea)
- Plaintiff’s Counsel: Radulescu LLP
- Case Identification: 2:23-cv-00420, E.D. Tex., 09/15/2023
- Venue Allegations: Plaintiff alleges venue is proper in any U.S. judicial district because Defendant is not a resident of the United States. The complaint also asserts Defendant has established minimum contacts with Texas through the sale and distribution of products within the state.
- Core Dispute: Plaintiff alleges that Defendant’s ultraviolet light-emitting diodes (UV LEDs) and products containing them infringe five U.S. patents related to the design, fabrication, and thermal management of such devices.
- Technical Context: The technology involves Group III-Nitride based semiconductor devices that emit ultraviolet light, a market significant for applications such as disinfection, medical imaging, and polymer curing.
- Key Procedural History: The complaint describes a series of communications between Plaintiff (or its predecessor-in-interest for certain patents) and Defendant beginning on May 4, 2022, and continuing through August 10, 2023, which allegedly provided Defendant with pre-suit notice of infringement for all asserted patents.
Case Timeline
| Date | Event |
|---|---|
| 2006-10-18 | ’551 Patent Priority Date |
| 2008-07-30 | ’687 Patent Priority Date |
| 2011-08-11 | ’420 Patent Priority Date |
| 2013-01-15 | ’687 Patent Issue Date |
| 2013-09-03 | ’391 Patent Priority Date |
| 2014-03-25 | ’551 Patent Issue Date |
| 2015-05-26 | ’420 Patent Issue Date |
| 2015-10-01 | ’848 Patent Priority Date |
| 2016-08-01 | Photon Wave established |
| 2017-04-01 | Photon Wave begins UVC epi-wafer development |
| 2018-12-01 | Photon Wave launches first UV-B and UV-C LED products |
| 2018-12-04 | ’848 Patent Issue Date |
| 2019-12-01 | Photon Wave launches second-generation UV LED products |
| 2021-01-26 | ’391 Patent Issue Date |
| 2022-05-01 | Photon Wave launches H-series products |
| 2022-05-04 | Predecessor-in-interest for ’848 and ’420 patents sends notice letter |
| 2023-08-10 | Plaintiff sends notice letter regarding all five asserted patents |
| 2023-09-15 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,354,687 - “Efficient Thermal Management and Packaging for Group III Nitride Based UV Devices,” issued January 15, 2013
The Invention Explained
- Problem Addressed: The patent describes the problem of inefficient heat removal in deep UV LEDs, where by-product heat can cause mechanical stress, premature device failure, and reduced light output, particularly when there is a mismatch in thermal expansion between the LED and its heat sink (’687 Patent, col. 2:1-24).
- The Patented Solution: The invention claims a method for fabricating a UV LED that improves thermal management by forming the semiconductor layers on a template, creating contacts, and then bonding the structure to a carrier with high thermal conductivity. This structure is designed to dissipate heat away from the active region of the device (’687 Patent, col. 4:28-44; Fig. 1).
- Technical Importance: This approach addresses a critical bottleneck in developing high-power UV LEDs by focusing on packaging and thermal pathways, which are as crucial to device performance and lifetime as the semiconductor structure itself (’687 Patent, col. 2:14-24).
Key Claims at a Glance
- The complaint asserts independent claim 17, a method claim (’687 Patent, col. 10:43-64; Compl. ¶55).
- Essential elements of claim 17 include the steps of:
- forming a template;
- forming a first semiconductor layer on the template;
- forming a light emitting quantum well region above the first layer;
- forming a second semiconductor layer over the quantum well region;
- forming first and second contact layers in electrical connection with the first and second semiconductor layers, respectively;
- providing a carrier comprising first and second contact zones; and
- bonding the first contact zone to the first-contact layer and the second contact zone to the second contact layer.
- The complaint does not explicitly reserve the right to assert dependent claims for this patent.
U.S. Patent No. 8,680,551 - “High Power Ultraviolet Light Sources and Method of Fabricating the Same,” issued March 25, 2014
The Invention Explained
- Problem Addressed: The patent addresses the challenge of current crowding and extreme device self-heating (joule heating) in deep UV LEDs, which arises from the high electrical resistance of the specialized epilayers required for short-wavelength emission (’551 Patent, col. 1:39-51).
- The Patented Solution: The invention proposes a vertically conducting LED structure with a specific layered arrangement that includes a highly thermally conductive submount. By placing this submount directly in the thermal path, the device is designed to efficiently dissipate heat, allowing for higher power operation (’551 Patent, col. 2:5-14; Abstract). The patent describes arranging the layers such that the heat-generating p-type layer is in close proximity to the submount (’551 Patent, Fig. 1).
- Technical Importance: This design directly targets thermal resistance, a key limiting factor for the power output and reliability of UV LEDs, by creating a more efficient vertical heat extraction path away from the active junction (’551 Patent, col. 1:39-64).
Key Claims at a Glance
- The complaint asserts independent claim 22, an apparatus claim (’551 Patent, col. 16:21-41; Compl. ¶84).
- Essential elements of claim 22 include an LED comprising in a layered arrangement:
- a metal p-contact;
- a highly thermally conductive submount attached to the metal p-contact, with a thermal conductivity of at least 100 W/m°K;
- a p-type layer on the submount;
- a quantum well layer on the p-type layer;
- an n-type layer on the quantum well layer;
- an n-type contact layer on the metal n-contact; and
- wherein the LED has a peak emission at 200-365 nm.
- The complaint does not explicitly reserve the right to assert dependent claims for this patent.
U.S. Patent No. 10,147,848 - “Contact Configuration for Optoelectronic Device,” issued December 4, 2018
- Technology Synopsis: This patent addresses light absorption and extraction issues in optoelectronic devices (’848 Patent, col. 1:8-12). The solution involves a specific contact configuration with a mesa structure and two distinct n-type metallic contact layers: a first layer for ohmic contact and a second, different layer made of a reflective material to improve light extraction (’848 Patent, Abstract).
- Asserted Claims: Independent claim 1 is asserted (Compl. ¶107).
- Accused Features: The complaint alleges that Defendant's PKD-H10-F35 and the Osram device contain the claimed n-type semiconductor layer, mesa, n-type contact region, and first and second distinct metallic contact layers (Compl. ¶¶108, 111-113, 116-117).
U.S. Patent No. 9,042,420 - “Device With Transparent and Higher Conductive Regions in Lateral Cross Section of Semiconductor Layer,” issued May 26, 2015
- Technology Synopsis: This patent addresses the trade-off between electrical conductivity and optical transparency in semiconductor layers (’420 Patent, col. 3:35-44). The invention describes a short period superlattice (SPSL) layer with lateral inhomogeneities, creating distinct regions that are more transparent to light and other regions that are more electrically conductive, thereby optimizing both properties simultaneously (’420 Patent, Abstract).
- Asserted Claims: Independent claim 1 is asserted (Compl. ¶128).
- Accused Features: The complaint alleges the accused devices contain the claimed SPSL semiconductor layer with laterally varying composition, resulting in a set of transparent regions and a set of higher conductive regions (Compl. ¶¶129-133, 136-138).
U.S. Patent No. 10,903,391 - “Optoelectronic Device with Modulation Doping,” issued January 26, 2021
- Technology Synopsis: This patent aims to reduce defects and hole trapping in p-type doped semiconductor layers, which can degrade device reliability (’391 Patent, col. 1:25-30). The solution involves a heterostructure with a specific "modulation doping" profile, particularly a group III nitride electron blocking layer that includes alternating sublayers of higher and lower aluminum content (’391 Patent, Abstract; col. 1:40-46).
- Asserted Claims: Independent claim 1 is asserted (Compl. ¶149).
- Accused Features: The complaint alleges the accused products contain the claimed heterostructure, including the group III nitride active region, n-type and p-type contact layers, a p-type electrode, and the critical electron blocking layer comprising a plurality of alternating sublayers (Compl. ¶¶150, 152, 154, 156).
III. The Accused Instrumentality
- Product Identification: The accused instrumentalities are Defendant’s UV LED products, including packaged chips (e.g., Photon Wave PKD-H10-F35), bare LED chips (e.g., Photon Wave PCD-H10), and third-party products that allegedly incorporate Defendant’s LED chips (e.g., Osram 720-SUCULDP1VCMBMG57) (Compl. ¶¶ 24, 27, 53).
- Functionality and Market Context: The complaint alleges these products are ultraviolet LEDs designed for applications requiring UV-B and UV-C light (Compl. ¶¶ 29-31, 36). Defendant’s website is cited as claiming its technology enables "higher efficiencies and longer lifetime" and supports "high injection current operation" due to a "large active area and a uniform current spreading design" (Compl. ¶¶ 36-37). The complaint supports its allegations with numerous transmission electron microscope (TEM) and scanning electron microscope (SEM) images of the accused products, which purport to show their internal layered structures (Compl. ¶¶ 58, 62, 89, 110, 130). A TEM image from the complaint shows the layered structure of the accused PKD-H10-F35 device, identifying a "Template" and "First layer" alleged to meet elements of the '687 patent (Compl. ¶¶ 58-59).
IV. Analysis of Infringement Allegations
- ’687 Patent Infringement Allegations
| Claim Element (from Independent Claim 17) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a method for forming a light emitting diode comprising the steps of: forming a template; | The accused method includes forming a template, as shown in a TEM image of the accused product. | ¶58 | col. 10:43-44 |
| forming a first layer on said template wherein said first layer has a first conductivity and a composition comprising AlxInyGa1-x-yN...; | The accused method includes forming a first layer with the specified composition on the template, as depicted in TEM images. | ¶59 | col. 10:45-48 |
| forming light emitting quantum well region above said first layer...; | The accused method includes forming a light emitting quantum well region above the first layer, as depicted in TEM images. | ¶60 | col. 10:49-52 |
| and forming a second layer over said light emitting quantum well with a second conductivity...; | The accused method includes forming a second layer over the quantum well region, as depicted in TEM images. | ¶61 | col. 10:52-55 |
| forming a first-contact layer in electrical connection with said first layer; forming a second-contact layer in electrical connection with said second layer; | The accused method includes forming first and second contact layers, as shown in SEM and microscope images. | ¶62 | col. 10:56-59 |
| providing a carrier wherein said carrier comprises a first contact zone and a second contact zone; | The accused method includes providing a carrier with distinct contact zones, as shown in optical microscope images of the device deposed on a carrier. | ¶63 | col. 10:60-61 |
| and bonding said first contact zone to said first-contact layer and said second contact zone to said second contact layer. | The accused method includes bonding the carrier's contact zones to the corresponding contact layers on the diode. | ¶¶63-64 | col. 10:62-64 |
Identified Points of Contention:
- Scope Questions: The complaint asserts infringement of a method claim under 35 U.S.C. § 271(g), which pertains to importing or selling a product "made by a process patented in the United States." A central question will be whether the accused products sold in the U.S. are, in fact, manufactured using a process that includes every step of claim 17, in the recited order.
- Technical Questions: What evidence does the complaint provide that the manufacturing process includes the specific step of "bonding said first contact zone to said first-contact layer and said second contact zone to said second contact layer"? The complaint presents images of a final product on a carrier and the back surface after removal, from which it infers the bonding step occurred (Compl. ¶¶ 63-64), but direct evidence of the manufacturing process itself is not provided.
’551 Patent Infringement Allegations
| Claim Element (from Independent Claim 22) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| an LED comprising in a layered arrangement: a metal p-contact; | The accused products are LEDs that contain a metal p-contact on the back surface of the LED chip. | ¶¶85-86 | col. 16:22-23 |
| a highly thermally conductive submount attached to said metal p-contact, wherein said highly conductive submount has a thermal conductivity of at least 100 W/m°K; | The accused products allegedly comprise a submount attached to the p-contact that includes materials with thermal conductivity greater than 100 W/m°K. | ¶87 | col. 16:24-27 |
| a p-type layer on said thermally conductive submount, said p-type layer comprising Al1-x-yInyGaxN...; | The accused LEDs have a p-type layer on the submount, as shown in TEM images. | ¶88 | col. 16:28-30 |
| a quantum well layer on said p-type layer...; | The accused LEDs have a quantum well layer on the p-type layer, as shown in TEM images. | ¶88 | col. 16:31-33 |
| an n-type layer on said quantum well layer...; | The accused LEDs have an n-type layer on the quantum well layer, as shown in TEM images. | ¶88 | col. 16:34-36 |
| and an n-type contact layer on said metal n-contact; | The accused LEDs have a metal n-contact electrically connected with the n-type layer via an n-type contact layer, as shown in SEM images. | ¶89 | col. 16:37-38 |
| and wherein said LED has a peak emission at 200-365 nm | The accused PKD-H10-F35 product has a peak emission within the claimed range, as indicated by its packaging label. | ¶90 | col. 16:39-41 |
- Identified Points of Contention:
- Scope Questions: A primary question may be the interpretation of "on" in the claim's layered structure (e.g., "p-type layer on said... submount"). Does this require direct physical contact, or can intervening layers (such as the metal p-contact) exist between the p-type layer and the submount? The complaint’s theory appears to rely on an interpretation that does not require direct contact.
- Technical Questions: What evidence supports the allegation that the submount has a thermal conductivity of "at least 100 W/m°K"? The complaint alleges the submount "includes material having a thermal conductivity higher than 100 watts per meter Kelvin" and provides an elemental analysis chart, but does not provide a direct measurement of the submount's overall thermal conductivity (Compl. ¶87).
V. Key Claim Terms for Construction
Term from ’551 Patent, Claim 22: "on" (as in "a p-type layer on said thermally conductive submount")
- Context and Importance: The spatial relationship between the layers is fundamental to this apparatus claim. Whether "on" requires direct, immediate contact or merely positional support will be critical. If construed to mean direct contact, the presence of the "metal p-contact" between the p-type layer and the submount, as recited in the claim and alleged in the complaint, may raise non-infringement or invalidity questions.
- Evidence for a Broader Interpretation: The claim separately recites the p-type layer and the submount, and the relationship "on" may be interpreted functionally to mean supported by, rather than requiring direct physical abutment, which is a common understanding in semiconductor patent claims unless specified otherwise.
- Evidence for a Narrower Interpretation: The patent's figures, such as Figure 1 of the related ’687 patent (which illustrates a similar structure), depict layers stacked directly on one another, which a defendant might argue suggests an intention to claim direct contact.
Term from ’687 Patent, Claim 17: "bonding"
- Context and Importance: This is a key step in the claimed manufacturing method. The scope of "bonding" will determine what types of manufacturing processes infringe. Practitioners may focus on this term because the evidence provided in the complaint infers this step from images of the final product rather than showing the process itself (Compl. ¶¶ 63-64).
- Evidence for a Broader Interpretation: The specification discusses bonding generally and refers to using a "bonding layer... such as a metal pad, solder or the like," suggesting the term is not limited to a single specific technique but covers various methods of attachment (’687 Patent, col. 4:37-40).
- Evidence for a Narrower Interpretation: A defendant may argue that specific examples in the patent, if they exist, limit the term "bonding" to a particular type of metallurgical or chemical bond, potentially excluding simple adhesive or pressure-based methods if those are used by the accused infringer.
VI. Other Allegations
- Indirect Infringement: The complaint alleges induced infringement for all patents. The basis for this allegation is that Defendant provides product data sheets, website information, and other instructions that allegedly encourage and direct customers and end-users on how to incorporate and use the accused LED products in an infringing manner (e.g., in sterilization devices) (Compl. ¶¶ 40, 79, 98, 122, 143, 163).
- Willful Infringement: The complaint alleges willful infringement for all asserted patents. For the ’848 and ’420 patents, willfulness is based on alleged actual knowledge or willful blindness dating from a May 4, 2022 notice letter from a predecessor-in-interest (Compl. ¶¶ 119-121, 140-142). For the ’687, ’551, and ’391 patents, willfulness is based on alleged actual knowledge or willful blindness dating from an August 10, 2023 notice letter sent by Plaintiff's counsel (Compl. ¶¶ 75-78, 100-102, 159-162). The complaint alleges that Defendant continued its infringing conduct after receiving these notices.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of process verification: For the method claim of the ’687 patent, can Plaintiff produce evidence that the accused products sold in the U.S. are manufactured using a process that practices every claimed step? The analysis will likely depend on discovery into Defendant’s proprietary manufacturing techniques.
- A key question of claim construction will be the spatial term "on" in the layered structure of the ’551 patent. The court's interpretation of whether "a p-type layer on said... submount" requires direct physical contact will be pivotal, as the claim itself places a "metal p-contact" between these components.
- An evidentiary and technical question will be one of meeting quantitative limitations: The case will involve factual disputes over whether the accused products meet specific numerical thresholds recited in the claims, such as the "at least 100 W/m°K" thermal conductivity of the submount in the ’551 patent and the specific area percentages for transparent and conductive regions in the ’420 patent.