Electrophoretic deposition of converter materials onto thin non-conductive substrates

Abstract

A method of making a converter layer includes performing electrophoresis to deposit converter material particles in a suspension composition onto a thin, non-conductive substrate to make a first intermediate structure; and fixing the converter material particles with a binder material and / or an inorganic coating in order to produce the converter layer. A converter assembly for a light emitting diode (LED), comprising: a converter layer comprising: electrophoretically deposited converter particles in combination with one or more of: a binder material; an inorganic coating of converter particles, and an inorganic coating of binder material when present; and a filler material.

Description

Technical Field

[0002] This disclosure relates to electrophoretically depositing converter materials (including phosphor materials) onto a non-conductive substrate, preferably onto a thin non-conductive substrate. This disclosure also generally relates to converter layers comprising such electrophoretically deposited converter materials for phosphor-converting light-emitting diodes (pc-LEDs), and devices and arrays comprising these converter layers. The electrophoretically deposited converter material, specifically phosphor material, is densely packed onto a non-conductive substrate. The converter layer comprises: electrophoretically deposited converter material (including converter particles, specifically phosphor particles), combined with one or more of the following: a binder material; an inorganic coating of the converter particles and the binder material; and optionally one or more filler materials. Background Technology

[0004] Semiconductor light-emitting devices, or optical power emitting devices (such as devices that emit ultraviolet (UV) or infrared (IR) light power), including light-emitting diodes, resonant cavity light-emitting diodes, vertical cavity laser diodes, and edge-emitting lasers, are among the most efficient light sources currently available. Due to their compact size and low power requirements, semiconductor light or optical power emitting devices (referred to herein as LEDs for simplicity) are attractive candidates as light sources (such as camera flashes) in handheld battery-powered devices (such as cameras and mobile phones). They can also be used, for example, in other applications such as automotive lighting, video lighting, and general lighting (such as lighting for homes, shops, offices, and studios), theater / stage lighting, and architectural lighting.

[0005] High-intensity / high-brightness light-emitting devices capable of operating across the visible spectrum include III-V semiconductors, specifically binary, ternary, and quaternary alloys of gallium, aluminum, indium, and nitrogen, also known as III-nitride materials. Typically, III-nitride light-emitting devices are fabricated by epitaxially growing stacks of semiconductor layers with different compositions and doping concentrations on a growth substrate such as sapphire, silicon, silicon carbide, III-nitride, or other suitable substrates using metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), or other epitaxial techniques. Sapphire is commonly used as the growth substrate due to its widespread commercial availability and relative ease of use. The stacks grown on the growth substrate typically involve forming one or more n-type layers (e.g., doped with Si) on the substrate, forming light-emitting or active regions on the one or more n-type layers, and forming one or more p-type layers (e.g., doped with Mg) on ​​the active regions.

[0006] Phosphor-converting LEDs (pc-LEDs) include a converter layer, such as a phosphor layer on the LED pump. The phosphor layer absorbs energy and converts the incident wavelength to a lower energy wavelength. For example, the phosphor layer converts high-energy LED light into a more desired color spectrum. In practice, the composition and structure of the phosphor layer are selected to meet desired performance criteria. Reliability is a requirement for pc-LEDs. The increasing demand for pc-LEDs operating at high power levels necessitates the development of pc-LED materials that maintain good stability while operating at high temperatures.

[0007] Many applications require thin layers of densely packed converter particles (e.g., phosphor particles) only a few particle diameters thick. Such layers cannot be achieved by scraping or spin coating, for example, with phosphors in silicone adhesives, because the phosphor particles easily interfere with liquid flow during layer formation. Spray coating is also difficult to control for thin layers.

[0008] The presence of organic materials in traditional phosphor layers makes them prone to degradation under high luminous flux and high temperature, which can lead to premature reliability failure of pc-LEDs.

[0009] There is a need to develop methods for depositing thin layers of densely packed converter particles (e.g., phosphor particles) and for fabricating converter layers / designs that can overcome reliability defects under extreme operating conditions. Summary of the Invention

[0011] This document provides converter layers for LEDs, LED devices and arrays including these converter layers, and light sources, and provides methods for fabricating the converter layers. In one or more aspects, the converter layers (i.e., phosphor layers) are deposited on a thin, non-conductive substrate by electrophoretic deposition. Preferably, these layers are thin and densely packed. Thin, densely packed layers offer advantages over reliability deficiencies in the prior art, such as better scattering control and better thermal conductivity compared to conventionally fabricated converter particle layers.

[0012] In one aspect, a method for preparing a converter layer includes: performing electrophoresis to deposit converter material particles in a suspension composition onto a thin, non-conductive substrate to prepare a first intermediate structure; and fixing the converter material particles with an adhesive material and / or an inorganic coating to prepare a converter layer.

[0013] Another aspect provides a method for manufacturing an inorganic phosphor assembly for a light-emitting diode (LED), comprising: performing electrophoresis to deposit phosphor particles in a suspension composition onto a polycrystalline ceramic plate of a phosphor material to prepare a first intermediate structure; fixing the phosphor particles with an adhesive material and / or an inorganic coating derived from a sol-gel material to prepare a second intermediate structure; and distributing a filler material between the phosphor particles and the adhesive material and / or the inorganic coating to prepare a converter layer on the polycrystalline ceramic plate; and removing at least any organic material from the suspension composition and the sol-gel material to prepare the inorganic phosphor assembly.

[0014] Another aspect is a converter assembly for a light-emitting diode (LED), comprising: a converter layer including: electrophoretically deposited converter particles, combined with one or more of the following: an adhesive material; an inorganic coating of the converter particles (and the adhesive material (if present)); and a filler material.

[0015] Another aspect is a light-emitting diode (LED) array comprising: a stacked mesa including a semiconductor layer including an active region; and a converter assembly according to any embodiment herein attached to the mesa.

[0016] In another aspect, a method of manufacturing a light source includes attaching a converter assembly according to any embodiment of the present document to a light-emitting diode (LED) or an LED array. Attached Figure Description

[0018] To enable a detailed understanding of the presentation of the features of this disclosure described above, a more specific description of the disclosure, as briefly summarized above, can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only typical embodiments of the disclosure and are therefore not intended to limit the scope of the disclosure, as other equally effective embodiments are permissible. The line drawings herein are not drawn to scale.

[0019] Figure 1A-1B , Figure 2A-2B , Figures 3A-3B and Figure 4 This is a schematic cross-sectional view of a converter assembly including a converter layer according to various embodiments; Figure 5A , 5B The 5C provides illustrations in which ( Figure 5A ) No thin non-conductive substrate was placed and in which ( Figure 5B and Figure 5C A schematic cross-sectional view of a portion of an electrophoretic deposition (EPD) cell with a thin, non-conductive substrate on which a thin substrate is placed. Figures 6A-6F This is a schematic cross-sectional view of a converter assembly during operation of a method for manufacturing a converter assembly using electrophoretic deposition, according to one embodiment. Figure 7 It is based on Figures 6A-6F A process flow diagram of the method for manufacturing converter components; Figures 8A-8H This is a schematic cross-sectional view of the converter assembly and the final converter layer during operation according to an embodiment of a method for fabricating a converter assembly and a final converter layer using electrophoretic deposition. Figure 9 It is based on Figures 8A-8H A process flow diagram of the method for manufacturing converter components; and Figure 10 An exemplary headlight illumination system including a converter component and / or converter layer according to embodiments herein is schematically illustrated. Detailed Implementation

[0021] Before describing several exemplary embodiments of this disclosure, it should be understood that this disclosure is not limited to the details of the structures or process steps set forth in the following description. This disclosure can have other embodiments and can be practiced or performed in a variety of ways.

[0022] The term "substrate" is used herein, according to one or more embodiments, to refer to a structure having a surface (or a portion thereof) in the intermediate or final stage, on which a process is performed. Furthermore, in some embodiments, reference to a substrate also refers only to a portion of the substrate, unless the context explicitly indicates otherwise. Additionally, according to some embodiments, reference to deposition on a substrate includes deposition on a bare substrate, or deposition on a substrate on which one or more thin films, features, or materials have been deposited or formed.

[0023] In one or more embodiments, "substrate" means any substrate on which thin film processing is performed during a manufacturing process, or a material surface formed on a substrate. "Device substrate" is the substrate of the final product or device. In exemplary embodiments, depending on the application, the substrate surface on which processing is performed includes materials such as silicon, silicon dioxide, silicon-on-insulator (SOI), strained silicon, amorphous silicon, doped silicon, carbon-doped silicon oxide, germanium, gallium arsenide, glass, sapphire, and any other suitable materials such as metals, metal nitrides, III-nitrides (e.g., GaN, AlN, InN, and alloys), metal alloys, and other conductive materials. The substrate includes, but is not limited to, light-emitting diode (LED) devices, including uLED devices. In some embodiments, the substrate is exposed to pretreatment processes such as polishing, etching, reduction, oxidation, hydroxylation, annealing, UV curing, electron beam curing, and / or baking of the substrate surface. In addition to performing thin film processing directly on the surface of the substrate itself, in some embodiments, any step of the disclosed thin film processing steps is also performed on an underlayer formed on the substrate, and the term "substrate surface" as indicated by the context is intended to include such an underlayer.

[0024] Methods for depositing thin films include, but are not limited to: sputtering deposition, atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma-enhanced atomic layer deposition (PEALD), plasma-enhanced chemical vapor deposition (PECVD), and combinations thereof.

[0025] When LED is mentioned, it refers to a light-emitting diode that emits light when current passes through it. In one or more embodiments, such as headlights, the LEDs described herein have one or more characteristic dimensions (e.g., height, width, etc.) ranging from greater than or equal to 1 micrometer to less than or equal to 300 micrometers, as well as all values ​​and subranges therebetween. In one or more embodiments, the height and width are one or more dimensions that take values ​​ranging from 40 to 300 micrometers. The micrometers mentioned herein allow for variations of ±1-5%. In some instances, LEDs are referred to as microLEDs (uLEDs or µLEDs), referring to light-emitting diodes having one or more characteristic dimensions (e.g., height, width, etc.) on the order of micrometers or tens of micrometers.

[0026] The converter layer (i.e., the phosphor layer) absorbs energy and converts the incident wavelength to a higher wavelength with lower energy. In this paper, in one or more aspects, the converter layer includes phosphor particles as a downconverter material. Other downconverter materials may be semiconductor nanoparticles (quantum dots), which can be used in combination with the phosphor particles.

[0027] This disclosure includes fabricating a converter layer (e.g., a phosphor layer) on a thin substrate, which may be glass-based, sapphire, garnet, alumina, or other materials, such as thin, non-conductive materials. A densely packed layer of particles is applied to the thin, non-conductive substrate by electrophoretic deposition, followed preferably by sintering away all organic matter. These layers can be used to modulate the luminescence properties of sintered light converters (such as yttrium aluminum garnet plates) or to apply phosphors to substrates with defined scattering properties, such as ceramic converters, which can be mounted on LEDs.

[0028] The term "non-conductive" substrate refers to a substrate that functions as an insulator. Many ceramics and polymers are considered insulators, while metals and semiconductor materials are not. In one or more aspects, a non-conductive substrate has a conductivity below 10... -10 (Ohm.m) -1 The electrical conductivity.

[0029] The term "densely packed" granular layer refers to a layer having a desired maximum particle volume fraction that depends on polydispersity and shape. In one or more aspects, a densely packed granular layer has a maximum particle volume fraction of approximately 50%, and preferably for monodisperse spheres, this value is about 64% (randomly densely packed).

[0030] There is a need to develop methods for depositing thin layers of densely packed converter particles (e.g., phosphor particles) onto a substrate (e.g., a non-conductive substrate used in LEDs, specifically uLEDs). Depositing layers only a few particle diameters thick is challenging, and methods including blade coating, spin coating, and spray coating may not be sufficient. Electrophoretic deposition (EPD) is a method for applying densely packed particle layers onto a substrate. Traditionally, EPD has been a method for depositing thin layers only on conductive substrates. Surprisingly, electrophoretic deposition has been found to be an efficient way to apply phosphor layers onto thin, non-conductive substrates. Figures 5A-5C A cross-sectional view is provided to illustrate ( Figure 5A ) No thin non-conductive substrate 20 is placed and in which ( Figure 5B and Figure 5C A schematic diagram of a portion of the EPD unit 1 on which a thin, non-conductive substrate 20 is placed. Figure 5A In the -5C, the first electrode 21a and the second electrode 21b of the EPD unit are separated by a distance "d". During use, an electric field (E) (V / d) is applied to the unit. The first electrode 21a experiences a first voltage V1, and the second electrode 21b experiences a second voltage V2. The potential difference 2, for example, the incremental voltage (ΔV), is |V1-V2|, equal to E*d. Figure 5A In the absence of an electrochemical reaction, the EPD unit acts as a capacitor, charging when a potential difference is applied. Figure 5BIn this process, when a thin, non-conductive substrate 20 with thickness d1 is introduced into the cell, the distance between the first electrode 21a and the second electrode 21b becomes d2. The thickness d1 is negligible compared to d2. Figure 5C (that is) Figure 5B As shown in the simplified version, due to the thin / negligible substrate thickness, any potential reduction over this thickness range is negligible even if the dielectric constant changes. The presence of a thin, non-conductive substrate with thickness d1 does not significantly alter the properties of the capacitor, and the difference between d (e.g., 0.5–1 cm) and d2 is negligible. In some aspects, d1 is in the range of greater than or equal to 10 micrometers to less than or equal to 200 micrometers, including all values ​​and subranges therebetween, including greater than or equal to 15 micrometers to less than or equal to 100 micrometers, and greater than or equal to 20 micrometers to less than or equal to 50 micrometers.

[0031] Electrophoretic deposition of YAG phosphors for conductive surfaces (stainless steel) was performed, and the current during deposition was compared with that during deposition on thin (170 µm) glass or (100 µm) alumina (non-conductive) substrates attached to stainless steel electrodes. The initial current was the same for both stainless steel and non-conductive substrates, but the current drop over time was much more pronounced for the non-conductive substrates.

[0032] Although EPD is a standard technique for conductive substrates, electrophoretic deposition has unexpectedly proven to be an efficient way to apply phosphor layers for thin substrates and using low-conductivity suspensions. Some applications include depositing phosphor layers onto sintered ceramic plates (such as doped yttrium aluminum garnet), where it can be used to modify the emission spectrum. This enables the fabrication of warm white converters based on ceramic yttrium aluminum garnet materials. Other applications include depositing phosphor layers onto undoped yttrium aluminum garnet, which can be cut into plates of desired sizes, offering better control than glass or sapphire. Another application is the mounting of phosphor layers onto blue LEDs with thin intermediate layers that define scattering. Phosphor layers can be fabricated separately onto thin substrates, which can then be binned and bonded to the LED, improving color yield in the EPD process during PC-LED manufacturing.

[0033] The “thin” substrate used in this paper has a thickness that does not significantly alter the potential reduction property of the EPD cell.

[0034] Sintered ceramic phosphor plates are used for conversion in PC-LEDs, particularly for automotive applications. These plates are used in many products. These plates consist of only a single phosphor. Therefore, it is difficult to tune correlated color temperature (CCT), color point, color rendering index, or other properties such as color rendering index (CRI) and / or R9 (the accuracy with which the light source will reproduce vibrant red) for specific applications. Applying the phosphor on top of the ceramic plate / substrate should preferably be a thin, densely packed layer of particles, which keeps the system completely inorganic. EPD combined with, for example, sol-gel and atomic layer deposition for particle bonding provides such an opportunity. Further layers, such as reflective layers, can then be applied. Such components can also be used for blue laser conversion.

[0035] Another application requiring thin, densely packed phosphor layers is automotive headlights that incorporate micro-LED arrays. Such headlights must not only have high lumen output but also strong contrast between on and off pixels. Densely packed, thin, highly scattering converter layers help achieve this. Directly depositing phosphors onto LED arrays yields low efficiency and is complex to rework. The proposed process allows phosphor layers to be deposited on a thin substrate, which, after checking for color spots and uniformity, can be attached to the LED array. Because ceramics and phosphors are very temperature-stable, all organic matter can be removed before mounting onto the LEDs via thermal or photothermal treatment.

[0036] For higher-temperature PC-LED applications, a monolithic ceramic phosphor layer is typically relied upon; however, this layer has limited color tunability and color quality range. This paper presents an electrophoretically deposited converter layer that meets high-temperature reliability requirements while providing a wider color tunability range and improved color quality.

[0037] The devices described herein include converter assemblies and / or converter layers comprising electrophoretically deposited converter particles. The electrophoretically deposited converter particles are densely packed and are only a few particles thick (e.g., 2-3 particles). In some aspects, the converter layer comprises a thickness ranging from greater than or equal to 2 micrometers to less than or equal to 50 micrometers, and all values ​​and subranges thereof, including greater than or equal to 2 micrometers to less than or equal to 5 micrometers, and greater than or equal to 10 micrometers to less than or equal to 50 micrometers. The converter layer is fabricated on a thin, non-conductive substrate, which may or may not be removed for the final application.

[0038] Figure 1AThis is a schematic cross-sectional view of a converter assembly including a converter layer according to one embodiment. The converter assembly 10A includes a converter layer 15A (e.g., a phosphor layer) situated on a thin, non-conductive substrate 20. A plurality of converter particles 25 (e.g., phosphor particles) are electrophoretically deposited onto the substrate 20. In this embodiment, an inorganic coating 30 is present on the converter particles 25 and on a first surface of the substrate 20. No filler material is present between the converter particles.

[0039] Figure 1B This is a schematic cross-sectional view of a converter assembly including a converter layer according to one embodiment. Figure 1A Similar to the schematic cross-sectional view, but with added filler material. The converter assembly 10B includes a converter layer 15B (e.g., a phosphor layer) on a thin, non-conductive substrate 20. A plurality of converter particles 25 (e.g., phosphor particles) are electrophoretically deposited on the substrate 20. In this embodiment, an inorganic coating 30 is presented on the converter particles 25 and on a first surface of the substrate 20. Filler material 35 is located between the converter particles 25 and the inorganic coating 30. In some embodiments, the substrate 20 is removed, and the converter layer 15 is transferred to a suitable device.

[0040] Figure 2A This is a schematic cross-sectional view of a converter assembly including a converter layer according to one embodiment. The converter assembly 40A includes a converter layer 45A (e.g., a phosphor layer) situated on a thin, non-conductive substrate 20. A plurality of converter particles 25 (e.g., phosphor particles) are electrophoretically deposited on the substrate 20. In this embodiment, an adhesive material 50 is present between portions of the converter particles 25 and a first surface of the substrate 20. No filler material is present between the converter particles and the adhesive material 50.

[0041] Figure 2B This is a schematic cross-sectional view of a converter assembly including a converter layer according to one embodiment. Figure 2A Similar to the schematic cross-sectional view, but with added filler material. The converter assembly 40B includes a converter layer 45B (e.g., a phosphor layer) on a thin, non-conductive substrate 20. A plurality of converter particles 25 (e.g., phosphor particles) are electrophoretically deposited onto the substrate 20. In this embodiment, an adhesive material 50 is present between portions of the converter particles 25 and a first surface of the substrate 20. A filler material 35 lies between the converter particles 25 and the adhesive material 50. In some embodiments, the substrate 20 is removed, and the converter layer 45B is transferred to a suitable device.

[0042] Figure 3AThis is a schematic cross-sectional view of a converter assembly including a converter layer according to one embodiment. The converter assembly 70A includes a converter layer 75A (e.g., a phosphor layer) situated on a thin, non-conductive substrate 20. A plurality of converter particles 25 (e.g., phosphor particles) are electrophoretically deposited on the substrate 20. In this embodiment, an inorganic coating 30 is present on the converter particles 25 and on the surface of the substrate 20, and an adhesive material 50 is present between portions of the converter particles 25 and the inorganic coating 30 and a first surface of the substrate 20. No filler material is present between the converter particles 25 and the inorganic coating 30 and the adhesive material 50.

[0043] Figure 3B This is a schematic cross-sectional view of a converter assembly including a converter layer according to one embodiment. Figure 3A Similar to the schematic cross-sectional view, but with added filler material. The converter assembly 70B includes a converter layer 75B (e.g., a phosphor layer) on a thin, non-conductive substrate 20. A plurality of converter particles 25 (e.g., phosphor particles) are electrophoretically deposited on the substrate 20. In this embodiment, an inorganic coating 30 is presented on the converter particles 25 and the surface of the substrate 20, and an adhesive material 50 is presented between portions of the converter particles 25 and the inorganic coating 30 and a first surface of the substrate 20. The filler material 35 is located between the converter particles 25 and the inorganic coating 30 and the adhesive material 50. In some embodiments, the substrate 20 is removed, and the converter layer 75B is transferred to a suitable device.

[0044] Figure 4 This is a schematic cross-sectional view of a converter assembly including a converter layer according to one embodiment, similar to FIG. 1, but with the addition of a reflective layer. In this respect, FIG. 2-3 may also have a reflective layer added to the surface of the converter layer opposite to the substrate. Figure 4 In this embodiment, the converter assembly 80 includes a converter layer 85 (e.g., a phosphor layer) on a thin, non-conductive substrate 20. A plurality of converter particles 25 (e.g., phosphor particles) are electrophoretically deposited onto the substrate 20. In this embodiment, an inorganic coating 30 is present on the converter particles 25 and on a first surface of the substrate 20. A filler material 35 is disposed between the converter particles 25 and the inorganic coating 30. A reflective layer 90 is disposed on the surface of the converter layer 85 opposite to the surface of the substrate 20. In some embodiments, the substrate 20 is removed, and the converter layer 85 is transferred to a suitable device.

[0045] In one or more aspects, a converter assembly for a light-emitting diode (LED) including a microLED comprises, or is composed of, the following: a converter layer comprising: electrophoretically deposited converter particles, combined with one or more of the following: an adhesive material; an inorganic coating of the converter particles, and, when present, the adhesive material; and a filler material. Preferably, the converter material particles are densely packed on a thin, non-conductive substrate.

[0046] In one or more embodiments, the converter layer includes a thickness ranging from greater than or equal to 2 micrometers to less than or equal to 50 micrometers (inclusive of all values ​​and subranges therein).

[0047] In one or more embodiments, a filler material selected from the group consisting of alumina, silica, aluminosilicates, and combinations thereof is present. In other embodiments, the filler material includes silicone.

[0048] In one or more embodiments, an adhesive material is present. In some embodiments, the adhesive material comprises inorganic particles, preferably silica.

[0049] In some embodiments, the converter components and / or converter layers are inorganic, substantially inorganic, or completely inorganic, meaning that the components or layers have been treated to remove any residual organic material from the processed material.

[0050] In some aspects, the converter assembly and / or converter layer includes a reflective layer on the surface of the converter layer opposite to a thin, non-conductive substrate. In one or more embodiments, the reflective layer comprises a thin metal film (e.g., aluminum (Al), silver (Ag), gold (Au)) or a multilayer stack of metal oxides.

[0051] In one or more embodiments, the converter assembly further includes a thin, non-conductive substrate. This thin, non-conductive substrate may have a thickness ranging from 10 micrometers or more to 200 micrometers or less (inclusive of all values ​​and subranges therebetween).

[0052] In some aspects, the thin non-conductive substrate comprises ceramic or glass. In one embodiment, the thin non-conductive substrate comprises a ceramic, specifically a polycrystalline ceramic plate of a phosphor material. In a particular embodiment, the thin non-conductive substrate is Lumiramic™, a Ce(III)-doped garnet material ceramic suitable as a monolithic ceramic segment. The phosphor material is preferably a garnet material. The garnet material preferably comprises: Ce(III)-doped garnet materials as follows: ((M I 1_ x _ y M II x M iIIy )3(Al1_ z M Iv z )50 i2, wherein: M¹ is Y or Lu; M II is Gd, La or Yb; M II i is Tb, Pr, Ce, Er, Nd or Eu, and M IV is Gd or Sc; wherein 0 < x < 1; 0 < y ≤ 0.1 and 0 < z < 1; or Ce(III) and / or Eu(II) doped silicon nitride ( M 2Si5N8) and silicon oxynitride materials ( M Si2O2N2), wherein M = alkaline earth metal.

[0053] In embodiments, the converter component and / or converter layer (preferably the phosphor layer) can be formed as a semiconductor structure for emitting blue light. In some embodiments, the converter particles include one or more types of phosphor particles. The phosphor particles can include, for example, particles of wavelength-converting materials that emit yellow or wavelength-converting materials that emit green and red, which will produce white light when the light emitted by each phosphor is combined with the blue light emitted by the light-emitting semiconductor structure. In other embodiments, the converter component or layer can be formed as a semiconductor structure for emitting UV light. In such embodiments, the phosphor particles can include, for example, particles of wavelength-converting materials for blue and yellow light, or particles of wavelength-converting materials for blue, green and red light. Phosphor particles that emit light of other colors can be added to customize the spectrum of the light emitted from the LED.

[0054] In embodiments, the phosphor particles can be composed of Y3Al5O 12 :Ce 3+ . The phosphor particles can be oxynitride aluminosilicates activated by rare earth metals and emitting amber to red light, with the general formula (Ca 1-x-y-z Sr x Ba y Mg z ) 1-n (Al 1-a+b Ba)Si 1-b N 3-b O b :RE n , wherein: 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ z ≤ 1, 0 ≤ a ≤ 1, 0 ≤ b ≤ 1 and 0.002 ≤ n ≤ 0.2, and RE can be selected from europium (II) and cerium (III).

[0055] In other embodiments, the phosphor particles can include aluminate garnet phosphors with the following general formula (Lu 1-x-y-a-b Yx Gd y )3(Al 1-z Ga z )5O 12 : Ce a Pr b , wherein: 0 < x < 1, 0 < y < 1, 0 ≤ z ≤ 0.1, 0 < a ≤ 0.2 and 0 ≤ b ≤ 0.1, such as Lu3Al5O 12 :Ce 3+ and Y3Al5O 12 :Ce 3+ , which emits light in the yellow-green range; and (Sr 1-x-y Ba x Ca y ) 2-z Si 5-a Al a N 8-a O a :Eu z 2+ , wherein 0 ≤ a < 5, 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and 0 ≤ z ≤ 1, such as Sr2Si5N8:Eu 2+ , which emits light in the red range. Other phosphors that emit green, yellow and red light may also be suitable, including: (Sr 1-a-b Ca b Ba c )Si x N y O z :Eu a 2+ (a = 0.002 - 0.2, b = 0.0 - 0.25, c = 0.0 - 0.25, x = 1.5 - 2.5, y = 1.5 - 2.5, z = 1.5 - 2.5), including SrSi2N2O2:Eu 2+ ; (Sr 1-u-v-x Mg u Ca v Ba x )(Ga 2-y- z Al y In z S4):Eu 2+ , including, for example, SrGa2S4:Eu 2+ ; Sr 1-x Ba x SiO4:Eu 2+ and (Ca 1-x Sr x )S:Eu 2+ where 0 ≤ x ≤ 1, including CaS:Eu2+ and SrS:Eu 2+ Other suitable phosphors include: CaAlSiN3:Eu 2+ (Sr,Ca)AlSiN3:Eu 2+ and (Sr, Ca, Mg, Ba, Zn)(Al, B, In, Ga)(Si, Ge)N3:Eu 2+ .

[0056] In other embodiments, the phosphor particles may also have the following general formula: (Sr 1-a-b Ca b Ba c Mg d Zn e Si x N y O z Eu a 2+ Where 0.002≤a≤0.2, 0.0≤b≤0.25, 0.0≤c≤0.25, 0.0≤d≤0.25, 0.0≤e≤0.25, 1.5≤x≤2.5, 1.5≤y≤2.5, and 1.5≤z≤2.5. The phosphor particles can also have the general formula: MmAaBbOoNn:Zz, where: element M is one or more divalent elements, element A is one or more trivalent elements, element B is one or more tetravalent elements, O is oxygen, which is optional and may not be present in the phosphor plate, N is nitrogen, and element Z is the activator; n = 2 / 3m + a + 4 / 3b − 2 / 3o, where m, a, and b can all be 1, o can be 0, and n can be 3. M is one or more elements selected from Mg (magnesium), Ca (calcium), Sr (strontium), Ba (barium), and Zn (zinc); element A is one or more elements selected from B (boron), Al (aluminum), In (indium), and Ga (gallium); element B is Si (silicon) and / or Ge (germanium); and element Z is one or more elements selected from rare earth or transition metals. Element Z is at least one or more elements selected from Eu (europium), Mg (manganese), Sm (samarium), and Ce (cerium). Element A can be Al (aluminum), element B can be Si (silicon), and element Z can be Eu (europium).

[0057] Phosphor particles can also be Eu 2+ Activated Sr-SiON, which has the general formula (Sr 1-a-b Ca b Ba c Si x N y O x Eu a, where a=0.002-0.2, b=0.0-0.25, c=0.0-0.25, x=1.5-2.5, y=1.5-2.5.

[0058] Phosphor particles can also be chemically modified Ce:YAG (yttrium aluminum garnet) phosphors, which are produced by doping Ce:YAG phosphors with trivalent praseodymium (Pr) ions. Phosphor particles can include a primary fluorescent material and a supplementary fluorescent material. The primary fluorescent material can be a Ce:YAG phosphor, and the supplementary fluorescent material can be a europium (Eu)-activated strontium sulfide (SrS) phosphor (“Eu:SrS”). The primary fluorescent material can also be a Ce:YAG phosphor or any other suitable yellow luminescent phosphor, and the supplementary fluorescent material can also be a mixed ternary crystal material of europium-activated calcium sulfide (CaS) and strontium sulfide (SrS) (CaS) x Sr 1_ x S:Eu 2+ The primary fluorescent material can also be a Ce:YAG phosphor or any other suitable yellow luminescent phosphor, and the supplementary fluorescent material can also be a europium-doped nitrogen silicate. Nitrogen silicate supplementary fluorescent materials can have the chemical formula (Sr...). 1-x-y-z Ba x Ca y )2Si5N8:Eu z 2+ , where 0≤x, y≤0.5 and 0≤z≤0.1.

[0059] In the embodiments, the phosphor particles may include strontium-lithium-aluminum:europium(II) ions (SrLiAl3N4:Eu). 2+ Class ) (also known as SLA), including MLiAl3N4: Eu 2+ (M = Sr, Ba, Ca, Mg). In specific embodiments, the phosphor particles may be selected from the group consisting of the following luminescent material systems: MLiAl3N4:Eu (M = Sr, Ba, Ca, Mg), M2SiO4:Eu (M = Ba, Sr, Ca), MSe 1-x S x:Eu (M=Sr, Ca, Mg), MSr2S4:Eu (M=Sr, Ca), M2SiF6:Mn (M=Na, K, Rb), M2TiF6:Mn (M=Na, K, Rb), MSiAlN3:Eu (M=Ca, Sr), M8Mg(SiO4)4Cl2:Eu (M=Ca, Sr),M3MgSi2O8:Eu (M=Sr, Ba, Ca), MSi2O2N2:Eu (M=Ba, Sr, Ca), M2Si 5-x Al x O x N 8-x Eu (M = Sr, Ca, Ba). However, other systems are also of interest and can be protected by coatings. Furthermore, combinations of particles of two or more different luminescent materials can be applied, such as, for example, combinations of green or yellow luminescent materials with red luminescent materials.

[0060] In the embodiments, the phosphor particles may include a mixture of any of the phosphors described above.

[0061] Optical elements can modify the direction, beam width, and beam shape of light emitted from each LED. Optical elements can be single or multiple. They can include, for example, converging or diverging lenses, aspherical lenses, Fresnel lenses, or gradient-index lenses. Other optical elements include mirrors, beam diffusers, filters, masks, apertures, collimators, or waveguides. Optical elements can be positioned at a distance from the LEDs to allow for the reception and redirection of light from multiple LEDs. Alternatively, optical elements can be positioned on top of each LED to individually guide, focus, or defocus the emitted LED light. Optical elements can be directly attached to the LED, attached to the LED via a transparent interlayer or plate, or held at a fixed distance from the LED by surrounding substrate fasteners.

[0062] Figure 6A –6F is a schematic cross-sectional view of a converter assembly during operation according to an embodiment of a method for fabricating a converter assembly using electrophoretic deposition (EPD), and Figure 7 It is based on Figure 6A -6F Manufacturing Method 700 Process Flow Diagram for Converter Components.

[0063] To facilitate EPD processes on non-conductive substrates, the suspension composition preferably has very low conductivity and the substrate is thin. To create such a suspension composition, the particles to be deposited are dispersed in a non-polar solvent. According to some embodiments, a polymer stabilizer and a charge modifier are added to obtain a colloidally stable suspension that can be manipulated in an electric field. The conductivity of the suspension composition can be on the order of pS / cm, for example, in the range of about 6–30 pS / cm. Non-polar solvents typically have low dielectric constants, and in such systems, no electrochemical reactions at the electrodes that regulate the current flowing through the system are identified during electrophoretic deposition. Therefore, the electric field initially present under applied voltage is determined by the geometry and dielectric constant. The electric field strength and the charge on the particles modulate the deposition. (e.g., Figure 5A , 5B During deposition (5C), the current drops more rapidly because charge generation at the electrodes cannot occur. The substrate can be a ceramic material such as garnet, like yttrium aluminum garnet (YAG) which has known light scattering, or it can be an ultrathin glass. The substrate can have a thickness of 200 µm and lower, down to, for example, 40 µm, 20 µm, or 10 µm.

[0064] refer to Figure 6A and Figure 7 At operation 710, electrophoresis is performed in a cell having a first electrode 21a and a second electrode 21b to deposit converter material particles (e.g., phosphor particles) onto a thin, non-conductive substrate. Figures 6A-6F The thickness of the intermediate substrate is not drawn to scale (it is enhanced for clarity). The substrate 20 is attached to the first electrode 21b by a suitable means (e.g., tape or insert holder) and contacts the second electrode 21b on one side (either electrode can be used for illustrative purposes only). The suspension composition includes particles of converter material 26 in a liquid carrier (e.g., a nonpolar liquid, such as alkanes or commercially available alkane mixtures such as isopar or shellsol), and other materials such as polymer stabilizers (e.g., poly(alkyl)methacrylates), and / or charge modifiers (e.g., chromium-anthracites). After an electrical potential is applied to the first electrode 21a and the second electrode 21b, a layer 24 of particles 25 having prepared the first intermediate structure is formed on the substrate 20.

[0065] exist Figure 7 In operation 720, and as Figure 6B As shown, the substrate 20 with layer 24 having particles 25 is removed from the second electrode 21b.

[0066] exist Figure 7At operation 740a, the substrate, including the particles, may optionally undergo a removal process, such as by curing to remove organic materials from the suspension composition. Possible organic residues (e.g., due to polymer stabilizers in the suspension) can be removed at high temperatures alone, or in combination with UV radiation or oxygen (O2) plasma treatment. In one or more embodiments, the substrate is treated to remove organic matter.

[0067] exist Figure 7 In operation 730, and as Figure 6C As shown, particles 25 are immobilized to prepare the converter layer. The immobilized converter material particles 25 include a binder material and / or an inorganic coating. To immobilize the particles 25 to the substrate 20 and to each other, a binder material applied by a coating technique such as sol-gel coating or atomic layer deposition, or both, can be used. Figure 6C The illustration shows particles being fixed with an adhesive via a sol-gel coating 51 for the purposes shown. It should be understood that, alternatively or in combination with an adhesive, particles can be fixed with an inorganic coating applied, for example, by atomic layer deposition.

[0068] Sol-gel coating processes can be performed as dip-coating processes into a sol-gel material solution. The material aggregates between particles and in the "necks" between particles and the surface, and is described as... Figure 6D The binder material 50 is used. The goal is to create sufficient strength for processing and for subsequent (multiple) steps. Particle fixation can also be performed by atomic layer deposition (ALD) of conformally applying an inorganic coating on all particles and the substrate. A combination of a sol-gel coating process followed by ALD can also be performed. After fixing particles 25 with a binder material and / or inorganic coating derived from the sol-gel material, as... Figure 6D The preparation of the second intermediate structure is described herein. Non-limiting examples of sol-gel materials include: TEOS (tetraethoxysilane: Si(OC2H5)4, EtOH [ethanol], HCl [hydrochloric acid], which undergoes hydrolysis and dilution in alcohol for a specified duration. The hydrolysis reaction is performed to form a silanol, which is capable of subsequent reactions to form a siloxane. TEOS (tetraethoxysilane) is ultimately converted to SiO2, which is an exemplary binder material.

[0069] exist Figure 7 In operation 740b, and as Figure 6DAs shown, the second intermediate structure, comprising particles 25 fixed with adhesive material 50, optionally undergoes curing and / or removal of any organic matter. Possible organic residues (e.g., due to polymer stabilizers in the suspension) can be removed solely at high temperatures, or in combination with UV radiation or oxygen (O2) plasma treatment. In cases where both sol-gel coating and inorganic coating processes are performed simultaneously, curing and / or removal of organic matter typically occurs after the sol-gel process and before the inorganic coating process. In one or more embodiments, the second intermediate structure is treated to remove organic matter.

[0070] exist Figure 7 In operation 750, and as Figure 6E As shown, filler material 35 is arranged between particles 25 and binder material 50 to prepare converter layer 45 on substrate 20.

[0071] exist Figure 7 In operation 760, and as Figure 6F As shown, the converter layer 45 on the substrate 20 is fixed to the LED or LED array 100, including uLED or uLED array, by adhesive 95.

[0072] Subsequently Figure 7 At operation 770, any further processing of the structure may optionally be performed to prepare the structure for a final application. Further processing includes, but is not limited to, depositing a reflective layer on the structure. Typically, the structure may be processed such that the surface is smooth enough to accept the reflective layer. Additionally, additional layers (e.g., metals) may be deposited to promote good adhesion of the reflective surface. Further processing also includes, but is not limited to, applying optical properties to the structure.

[0073] refer to Figure 8A and Figure 9 At operation 910 (similar to) Figure 6A and Figure 7 Operation 710) performs electrophoresis in a cell having a first electrode 21a and a second electrode 21b to deposit converter material particles (e.g., phosphor particles) onto a thin, non-conductive substrate. Figures 8A-8H The thickness of the intermediate substrate is not drawn to scale (it is enhanced for clarity). The substrate 20 is attached to the first electrode 21b by a suitable means (e.g., tape or insert holder) and contacts the second electrode 21b on one side (for illustrative purposes only, either electrode can be used). After applying an electrical potential to the first electrode 21a and the second electrode 21b, a layer 24 on which the particles 25 of the first intermediate structure are formed is formed on the substrate 20.

[0074] exist Figure 9 Operation 920 and such Figure 8B As shown (similar to) Figure 6B and Figure 7 In operation 720), the substrate 20 with the layer 24 having particles 25 is removed from the second electrode 21b.

[0075] exist Figure 9 Operation 930, and as Figure 8C-8D As shown, fixed particles 25 are used to prepare a converter layer. In this embodiment, the fixed converter material particles 25 comprise both a binder material and an inorganic coating. In this embodiment, to fix the particles 25 to the substrate 20 and to each other, a reference is used, for example... Figure 7 C discusses and in Figure 8C The sol-gel coating shown is used to apply the adhesive material 50, and coating techniques such as atomic layer deposition are used to apply an inorganic coating 30 to the first surface of the particles 25 and the substrate 20.

[0076] After fixing particles 25 with an adhesive material and / or inorganic coating derived from a sol-gel material, such as Figure 8C-8D The second intermediate structure was prepared in a descriptive manner.

[0077] exist Figure 9 Operation 940, and as Figure 8E As shown, a second intermediate structure comprising particles 25 fixed with adhesive material 50 and inorganic coating 30 is attached to transfer body 22. Figure 8F As shown and as Figure 9 In part of operation 940, substrate 20 is released. In some embodiments, the transfer body is a release layer, such as UV release tape or thermal release tape that is removed after the converter layer is transferred to the device in the next operation. The transfer body can also be released from the structure by dissolving it.

[0078] exist Figure 9 Operation 950, and as Figure 8G As shown, the converter layer 45 on the transfer body 22 is attached to the LED or LED array 100, including uLED or uLED array, by methods known in the art.

[0079] exist Figure 9 Operation 960, and as Figure 8H As shown, the transfer body was removed.

[0080] Subsequently, at operation 970, any further processing of the structure may optionally be performed to prepare the structure for the final application. Further processing includes, but is not limited to, depositing a reflective layer onto the structure. Typically, the structure can be processed such that the surface is smooth enough to accept the reflective layer. Additionally, additional layers (e.g., metals) may be deposited to promote good adhesion of the reflective surface. Further processing also includes, but is not limited to, imbuing the structure with optical properties.

[0081] In summary, the method described herein includes: preparing a converter layer, the method comprising: performing electrophoresis to deposit converter material particles in a suspension composition onto a thin non-conductive substrate to prepare a first intermediate structure; and fixing the converter material particles with an adhesive material and / or an inorganic coating to prepare the converter layer.

[0082] In one or more embodiments, the method further includes: distributing a filler material between the converter material particles and the binder material and / or inorganic coating, such that the converter layer further includes the binder material.

[0083] In one or more embodiments, the method further includes attaching the converter layer to the transfer body and removing a thin non-conductive substrate from the converter layer.

[0084] In some aspects, the electrophoresis process includes: positioning a first surface of a thin, non-conductive substrate adjacent to a first electrode of a pair of electrodes; exposing the thin, non-conductive substrate to a suspension composition comprising a converter material dispersed in a non-polar liquid; and applying an electric field to the pair of electrodes, whereby at least a portion of the converter material particles are deposited onto a second surface of the thin, non-conductive substrate to prepare a first intermediate structure.

[0085] In some aspects, fixing converter material particles includes: performing a sol-gel process by exposing a first intermediate structure to a sol-gel material solution, the sol-gel material comprising a precursor and a carrier of a binder material, and converting the precursor of the binder material into the binder material; and / or conformally performing thin film deposition of an inorganic material on the converter material particles (and the binder material (if present)) to prepare an inorganic coating.

[0086] In one or more embodiments, the method further includes removing any organic material from at least the suspension composition and the sol-gel material. In some embodiments, removing any organic material from at least the suspension composition and the sol-gel material includes exposing the converter layer to heat. In some embodiments, removing any organic material from at least the suspension composition and the sol-gel material includes exposing the converter layer to UV radiation or oxygen plasma treatment.

[0087] In some aspects, the arrangement of the filler material includes performing atomic layer deposition (ALD) of a metal oxide on the converter layer, the metal oxide preferably being selected from the group consisting of alumina, hafnium oxide, titanium oxide, and zirconium oxide. In some aspects, the arrangement of the filler material includes performing chemical vapor deposition (CVD) technology. In one specific embodiment, the arrangement of the filler material includes depositing silicone in the converter layer.

[0088] In one or more embodiments, the method further includes depositing a reflective material on the converter layer.

[0089] application The converter components and / or converter layers can be used in a variety of applications.

[0090] For example, the converter assembly according to Figure 5 includes: a substrate; a converter layer comprising converter particles, an inorganic coating (e.g., Al2O3), and a filler material (e.g., Al2O3); and a reflective layer suitable for a laser projection system. An exemplary laser projection system is one in which a blue laser is used to excite a Lumiramic™ plate (Ce(III)-doped garnet ceramic material). For such applications, the light intensity is very high, and a completely inorganic structure is preferred for reliability and lifespan considerations. In this application, using the techniques described herein, it is possible to deposit a red phosphor on top of the Lumiramic™ plate, such as BSSN[(Ba,Sr)2Si5N8:Eu or SLA Sr[LiAl3N4]:Eu. 2+ This provides an advantage in improving CRI / R9. Advantageously, converter layers (e.g., red phosphors) on the order of 2–5 micrometers can be used to tune the color point.

[0091] The converter components and / or converter layers described in this paper can also be used in pixelated headlight arrays composed of micro-LEDs. The amount of phosphor required to achieve the desired color point has strict limits; a thickness deviation of less than 1 µm results in an unacceptable color point for the LED array. Because it is difficult to tune electrophoretic deposition to such narrow limits, applying a phosphor layer deposited on a substrate, which is then attached to the LED array, is highly advantageous for process yield because the phosphor layer on the substrate can be measured individually and thus binned to the exact wavelength of the blue light chip. The substrate on which the particles are deposited is typically very thin to avoid excessive contrast loss, and it should have a certain level of scattering to minimize light propagation along the substrate. Thin garnet materials can be suitable for such substrates, and they can be fabricated down to 10 µm.

[0092] Figure 10An exemplary headlight illumination system 1000 using LEDs disclosed herein is schematically illustrated. The headlight illumination system 1000 includes an LED illumination array and lens system 1002 in electrical communication with an LED driver 1004. The headlight illumination system 1000 also includes a controller 1006, such as a microprocessor. The controller 1006 is coupled to the LED driver 1004. The controller 1006 may also be coupled to one or more auxiliary components 1008 and sensors 1010 associated with the headlight and operates according to instructions and configuration files stored in a memory 1012.

[0093] Sensor 1010 may include, for example, position sensors (e.g., gyroscopes and / or accelerometers) and / or other sensors that can be used to determine the position, velocity, and orientation of system 1000. Signals from sensor 1010 may be provided to controller 1006 to determine appropriate actions of controller 1006 (e.g., which LEDs are currently illuminating the target and which LEDs will illuminate the target after a predetermined amount of time).

[0094] During operation, the illumination from some or all of the pixels of the LED array in 1001 can be adjusted (disabled, operated at full intensity, or operated at intermediate intensity). As described above, the beam focusing or redirection of the light emitted by the LED array in 1002 can be electronically performed by activating one or more subsets of pixels, allowing for dynamic adjustment of the beam shape without moving the optics or changing the focus of the lenses in the illumination device.

[0095] LED lighting arrays and lens systems, such as those described herein, can support a variety of other applications that benefit from fine-grained intensity, spatial, and temporal control of light distribution. These applications can include, but are not limited to, precise spatial patterning of light emitted from pixel blocks or individual pixels. Depending on the application, the emitted light can be spectrally distinct, time-adaptive, and / or environmentally responsive. The emitting pixel array can provide pre-programmed light distributions in various intensity, spatial, or temporal modes. The associated optics can be distinct at the pixel, pixel block, or device level. Example emitting pixel arrays may include devices in a central block with shared control of high-intensity pixels having associated common optics, while edge pixels may have individual optics. Besides flashlights, common applications supported by emitting pixel arrays include video lighting, camera flashes, architectural and area lighting, and road lighting.

[0096] In some embodiments, each LED device in the light source array can be controlled individually, while in other embodiments, the LED group can be controlled as a block. In still other embodiments, both individual LEDs and LED groups can be controlled. To reduce overall data management requirements, control can be limited to on / off functionality or switching between a relatively small number of light intensity levels. In other embodiments, continuous changes in illumination intensity are supported. Individual and group-level control of light intensity is envisioned. In one embodiment, overlapping or dynamically selected control areas are also feasible, for example, in a group of light emitters overlapping in an array, although having a common LED, where individual control is possible depending on illumination requirements. In one embodiment, intensity can be individually controlled and adjusted by using pulse width modulation to set appropriate ramp time and pulse width for each LED. This allows for tiered LED activation to reduce power fluctuations and provide superior luminous intensity control.

[0097] Programmable light-emitting arrays, such as those disclosed herein, can also support a wide range of applications that benefit from fine-grained intensity, spatial, and temporal control of light distribution. This can include, but is not limited to, precise spatial patterning of light emitted from a block of LEDs or individual LEDs. Depending on the application, the emitted light can have different spectra, be time-adaptive, and / or responsive to the environment. In some embodiments, the light-emitting array can provide a pre-programmed light distribution with various intensities, spatial, or temporal patterns. The emitted light can be based at least in part on received sensor data and can be used for optical wireless communication. The associated optics can vary at the level of a single LED or multiple LEDs. Example light-emitting arrays may include a central block with high-intensity LEDs under common control (with associated common optics), while edge-placed LEDs may have independent optics. Common applications supported by light-emitting LED arrays include camera or video lighting, architectural and area lighting, and road lighting.

[0098] Programmable light-emitting arrays can be used to selectively and adaptively illuminate buildings or areas to enhance visual displays or reduce lighting costs. Furthermore, light-emitting arrays can be used to project media facades for decorative dynamic or video effects. Selective illumination of areas around pedestrians is feasible when combined with tracking sensors and / or cameras. LEDs with different spectra can be used to adjust the color temperature of the lighting, as well as to support garden lighting with specific wavelengths.

[0099] Road lighting is a crucial application that can significantly benefit from the use of programmable LED arrays. A single type of LED array can be used to simulate various road light types, allowing switching between Type I linear road lights and Type IV semi-circular road lights, for example, by appropriately activating or deactivating selected LEDs. Furthermore, road lighting costs can be reduced by adjusting beam intensity or distribution according to environmental conditions or usage time. For example, when there are no pedestrians, light intensity can be reduced and the distribution area narrowed. If the LEDs have different spectra, the color temperature of the light can be adjusted according to corresponding daytime, dusk, or nighttime conditions.

[0100] Programmable LEDs are also well-suited for applications requiring direct or projected displays. For example, automotive headlights requiring calibration, or displaying warning signs, emergency signs, or information markers, can use LED arrays for display or projection. This allows, for example, modification of the directionality of the light output from the automotive headlights. If the LED array consists of a large number of LEDs, or includes a suitable dynamic photomask, text or numerical information can be presented with user-guided placement. Directional arrows or similar indicators can also be provided. Example

[0102] Various embodiments are listed below. It will be understood that the embodiments listed below can be combined with all aspects and other embodiments according to the scope of the invention.

[0103] Example (a). A method for preparing a converter layer, the method comprising: performing electrophoresis to deposit converter material particles in a suspension composition onto a thin non-conductive substrate to prepare a first intermediate structure; and fixing the converter material particles with an adhesive material and / or an inorganic coating to prepare a converter layer.

[0104] Example (b). The method according to Example (a) further includes: distributing a filler material between the converter material particles and the binder material and / or inorganic coating, such that the converter layer further includes the filler material.

[0105] Example (c). The method according to Example (a) or (b) further includes: attaching the converter layer to the transfer body, and removing a thin non-conductive substrate from the converter layer.

[0106] Example (d). The method according to any one of Examples (a) to (c) wherein the thin non-conductive substrate comprises a thickness in the range of greater than or equal to 10 micrometers to less than or equal to 200 micrometers.

[0107] Example (e). The method according to any one of Examples (a) to (d), wherein converter material particles are densely packed on a thin non-conductive substrate.

[0108] Example (f). According to the method of any one of Examples (a) to (e), wherein the converter material particles are combined to form a layer on a thin, non-conductive substrate, the layer comprising a thickness in the range of greater than or equal to 2 micrometers to less than or equal to 50 micrometers.

[0109] Example (g). The method according to any one of Examples (a) to (f), wherein the electrophoresis is performed by: positioning a first surface of a thin nonconductive substrate adjacent to a first electrode of a pair of electrodes; exposing the thin nonconductive substrate to a suspension composition comprising a converter material dispersed in a nonpolar liquid; and applying an electric field to the pair of electrodes, thereby depositing at least a portion of the converter material particles onto a second surface of the thin nonconductive substrate to prepare a first intermediate structure.

[0110] Example (h). According to the method of Example (g), the suspension composition further includes: a polymer stabilizer and / or a charge modifier.

[0111] Example (i). According to the method of Example (h), the suspension composition includes a conductivity in the range of greater than or equal to 6 pS / cm to less than or equal to 30 pS / cm.

[0112] Example (j). The method according to any one of Examples (a) to (i), wherein fixing the converter material particles comprises: performing a sol-gel process by exposing a first intermediate structure to a sol-gel material solution, the sol-gel material comprising a precursor and a carrier of a binder material, and converting the precursor of the binder material into the binder material; and / or conformally performing thin film deposition of an inorganic material on the converter material particles (and the binder material (if present)) to prepare an inorganic coating.

[0113] Example (k). The method according to Example (j) further includes the removal of any organic material from at least the suspension composition and the sol-gel material.

[0114] Example (l). According to the method of Example (k), the removal of any organic material, at least the suspension composition and the sol-gel material, includes exposing the converter layer to heat.

[0115] Example (m). According to the method of Example (k), the removal of any organic material, at least the suspension composition and the sol-gel material, includes exposing the converter layer to UV radiation or oxygen plasma treatment.

[0116] Example (n). A method according to any one of examples (b) to (m), wherein the arrangement of the filler material comprises depositing a metal oxide on the converter layer, the metal oxide being preferably selected from the group consisting of: alumina, hafnium oxide, titanium oxide and zirconium oxide; optionally, the deposition comprises performing an atomic layer deposition (ALD) technique and / or performing a chemical vapor deposition (CVD) technique.

[0117] Example (o). A method according to example (b), wherein the arrangement of the filler material comprises depositing silicone in the converter layer.

[0118] Example (p). A method according to any one of examples (a) to (o), wherein the thin non-conductive substrate comprises ceramic or glass.

[0119] Example (q). A method according to example (p), wherein the thin non-conductive substrate comprises a ceramic, the ceramic being a polycrystalline ceramic plate of a phosphor material, the phosphor material being preferably a garnet material, which preferably comprises: Ce(III)-doped garnet material: ((M I 1_ x _ y M II x M i IIy )3(Al1_ z M Iv z )50 i2, wherein: M¹ is Y or Lu; M II is Gd, La or Yb; M II i is Tb, Pr, Ce, Er, Nd or Eu, and M IV is Gd or Sc; wherein 0 < x < 1; 0 < y ≤ 0.1 and 0 < z < 1 are satisfied; or Ce(III) and / or Eu(II)-doped silicon oxynitride ( M 2Si5N8) and silicon oxy-nitride materials ( M si2O2N2), wherein M = alkaline earth metal.

[0120] Example (r). A method according to any one of examples (a) to (q), further comprising depositing a reflective material on the converter layer.

[0121] Example(s). A method of manufacturing an inorganic phosphor component for a light-emitting diode (LED), comprising: performing electrophoresis to deposit phosphor particles in a suspension composition onto a polycrystalline ceramic plate of a phosphor material to prepare a first intermediate structure; fixing the phosphor particles with an adhesive material and / or an inorganic coating derived from a sol-gel material to prepare a second intermediate structure; and disposing a filler material between the phosphor particles and the adhesive material and / or the inorganic coating to prepare a converter layer on the polycrystalline ceramic plate; and removing any organic materials in at least the suspension composition and the sol-gel material to prepare an inorganic phosphor component.

[0122] Example(t). The method according to example(s), wherein the polycrystalline ceramic plate comprises: Ce(III)-doped garnet material: ((M I 1_ x _ y M II x M i IIy )3(Al1_ z M Iv z )50 i2, wherein: M¹ is Y or Lu; M II is Gd, La or Yb; M II i is Tb, Pr, Ce, Er, Nd or Eu, and M IV is Gd or Sc; wherein 0 < x < 1; 0 < y ≤ 0.1 and 0 < z < 1 are satisfied; or Ce(III) and / or Eu(II)-doped silicon nitride ( M 2Si5N8) and silicon oxynitride materials ( M Si2O2N2), wherein M = alkaline earth metal.

[0123] Example(u). The method according to example(s) or (t), wherein removing any organic materials in at least the suspension composition and the sol-gel material comprises: heating the second intermediate structure, or exposing the second intermediate structure to UV radiation or oxygen plasma treatment.

[0124] Example(v). The method according to any one of examples(s) to (u), wherein the disposition of the filler material comprises depositing alumina or silicone on the second intermediate structure.

[0125] Example(w). The method according to any one of examples(s) to (v), wherein the suspension composition has a conductivity in the range of greater than or equal to 6 pS / cm to less than or equal to 30 pS / cm.

[0126] Example (x). A converter assembly for a light-emitting diode (LED) includes: a converter layer comprising: electrophoretically deposited converter particles, combined with one or more of the following: an adhesive material; an inorganic coating of the converter particles (and the adhesive material (if present)); and a filler material.

[0127] Example (y). The converter assembly according to Example (x) further includes: a thin non-conductive substrate.

[0128] Example (z). A converter assembly according to Example (y), wherein the thin non-conductive substrate has a thickness ranging from greater than or equal to 10 micrometers to less than or equal to 200 micrometers.

[0129] Example (aa). A converter assembly according to any one of Examples (x) to (z), wherein converter material particles are densely packed on a thin non-conductive substrate.

[0130] Example (bb). A converter assembly according to any one of Examples (x) to (aa), wherein the converter layer includes a thickness in the range of greater than or equal to 2 micrometers to less than or equal to 50 micrometers.

[0131] Example (cc). A converter assembly according to any one of Examples (y) to (bb) further includes a reflective layer on the surface of the converter layer opposite to the thin non-conductive substrate.

[0132] Example (dd). A converter assembly according to any one of Examples (y) to (cc), wherein the thin non-conductive substrate comprises ceramic or glass.

[0133] Example (ee). A converter assembly according to Example (dd) wherein a thin, non-conductive substrate comprises a ceramic plate, said ceramic being a polycrystalline ceramic plate of a phosphor material, preferably a garnet material, which preferably comprises: Ce(III)-doped garnet material: ((M I 1_ x _ y M II x M i IIy )3(Al1_ z M Iv z )50 i2, where: M¹ is Y or Lu; M II Is it Gd, La, or Yb; M II i It is Tb, Pr, Ce, Er, Nd, or Eu, and M IVis Gd or Sc; where 0 < x < 1; 0 < y ≤ 0.1 and 0 < z < 1; or Ce(III) and / or Eu(II) doped nitrided silicate ( M 2Si5N8) and oxynitrided silicate material ( M Si2O2N2), where M = alkaline earth metal.

[0134] Example (ff). A converter component according to any one of Examples (y) to (ee), comprising a filler material, wherein the filler material is selected from the group consisting of alumina, silica, aluminosilicate, and combinations thereof.

[0135] Example (gg). A converter component according to any one of Examples (y) to (ee), comprising a filler material, wherein the filler material comprises silicone.

[0136] Example (hh). A converter component according to any one of Examples (y) to (gg), comprising an adhesive material, wherein the adhesive material comprises inorganic particles.

[0137] Example (ii). The converter component according to Example (hh), wherein the inorganic particles comprise silica.

[0138] Example (jj). A converter component according to any one of Examples (x) to (ii), wherein the converter particles comprise one or more types of phosphor particles.

[0139] Example (kk). A converter component according to any one of Examples (x) to (jj), which is completely inorganic.

[0140] Example (ll). A light emitting diode (LED) array, comprising: a stacked mesa having a semiconductor layer, the semiconductor layer including an active region; and a converter component according to one of Examples (x) to (kk) attached to the mesa.

[0141] Example (mm). The LED array according to Example (ll), wherein the mesa has at least one feature size greater than or equal to 1 micron to less than or equal to 300 microns.

[0142] Example (nn). The LED array according to Example (ll) or (mm), further comprising a thin non-conductive substrate, and the converter component is disposed on the thin non-conductive substrate.

[0143] Example (oo). The LED array according to any one of Examples (ll) to (nn), further comprising a phosphor layer disposed on the mesa, and the converter component is attached to the mesa.

[0144] Example (pp). The LED array according to Example (oo) is effective in an automotive headlight system.

[0145] Example (qq). The LED array according to any one of Examples (ll) to (nn) further includes a reflective layer on the surface of the converter assembly opposite to the surface of the thin non-conductive substrate.

[0146] Example (rr). The LED array according to Example (qq) is effective in a laser projection system.

[0147] Example (ss). An LED array according to any one of Examples (ll) to (rr) is completely inorganic.

[0148] Example (tt). A light source comprising: an LED array according to any one of Examples (ll) to (ss), which is attached to a device substrate.

[0149] Example (uu). According to the light source of Example (tt), one or a group of light-emitting diodes (LEDs) in the array can be individually addressed.

[0150] Example (vv). A method of manufacturing a light source includes attaching a converter assembly according to any one of Examples (x) to (kk) onto a light-emitting diode (LED) or an LED array.

[0151] Example (ww). The method according to Example (vv) further includes: identifying a reference color point distribution of one or a group of LEDs in the LED array; grading a set of converter components before attaching the converter components; wherein the attached converter components are selected from the set of converter components because the converter components include one or more desired conversion characteristics to adjust the LED array to achieve the desired color point distribution.

[0152] Throughout this specification, references to "an embodiment," "a particular embodiment," "one or more embodiments," or "embodiment" mean the specific feature, structure, material, or characteristic described in connection with an embodiment included in at least one embodiment of this disclosure. Therefore, the appearance of phrases such as "in one or more embodiments," "in a particular embodiment," "in one embodiment," or "in an embodiment" throughout this specification does not necessarily refer to the same embodiment of this disclosure. Furthermore, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0153] Many modifications and other embodiments of the invention will be conceived by those skilled in the art who benefit from the teachings presented in the foregoing description and associated drawings. Therefore, it should be understood that the invention is not limited to the specific embodiments disclosed, and that modifications and implementations are intended to be included within the scope of the appended claims. It should also be understood that other embodiments of the invention may be practiced where an element / step not specifically disclosed is missing.

Claims

1. A method for fabricating a converter layer, the method comprising: Electrophoresis was performed to deposit converter material particles in the suspension composition onto a thin, non-conductive substrate to prepare a first intermediate structure; and The converter material particles are fixed with an adhesive material and / or an inorganic coating to prepare the converter layer.

2. The method according to claim 1, further comprising: A filler material is disposed between the converter material particles and the adhesive material and / or the inorganic coating, such that the converter layer further includes the filler material.

3. The method according to claim 1, further comprising: The converter layer is attached to the transfer body, and the thin non-conductive substrate is removed from the converter layer.

4. The method of claim 1, wherein the thin non-conductive substrate comprises a thickness in the range of greater than or equal to 10 micrometers to less than or equal to 200 micrometers, and / or wherein a layer of converter material particles is formed on the thin non-conductive substrate, the layer comprising a thickness in the range of greater than or equal to 2 micrometers to less than or equal to 50 micrometers.

5. The method of claim 1, wherein the converter material particles are densely packed on a thin, non-conductive substrate.

6. The method of claim 1, wherein the electrophoresis is performed by: The first surface of the thin, non-conductive substrate is positioned adjacent to the first electrode of a pair of electrodes; The thin, non-conductive substrate is exposed to a suspension composition comprising a converter material dispersed in a non-polar liquid; and An electric field is applied to the electrodes, thereby depositing at least a portion of the converter material particles onto the second surface of a thin, non-conductive substrate to prepare a first intermediate structure.

7. The method of claim 6, wherein the suspension composition further comprises: The polymer stabilizer and / or charge modifier, and / or suspension composition includes a conductivity in the range of greater than or equal to 6 pS / cm to less than or equal to 30 pS / cm.

8. The method of claim 1, wherein the fixed converter material particles comprise: A sol-gel process is performed by exposing a first intermediate structure to a sol-gel material solution, the sol-gel material comprising a precursor and a carrier of an adhesive material, and converting the precursor of the adhesive material into the adhesive material; and / or The inorganic coating is prepared by conformally depositing a thin film of inorganic material onto the converter material particles and the binder material in the presence.

9. The method according to claim 8, further comprising: Remove at least any organic material from the suspension composition and the sol-gel material.

10. The method of claim 2, wherein the packing material comprises: Deposit metal oxides on the converter layer, and / or deposit silicone in the converter layer.

11. The method according to claim 1, wherein the thin non-conductive substrate comprises ceramic or glass, preferably the thin non-conductive substrate comprises ceramic, wherein the ceramic is a polycrystalline ceramic plate of phosphor material.

12. The method of claim 1, further comprising depositing a reflective material on the converter layer.

13. A converter assembly for a light-emitting diode (LED), comprising: A converter layer comprising: electrophoretically deposited converter particles, combined with one or more of the following: a binder material; an inorganic coating of the converter particles, and, when present, an inorganic coating of the binder material; and a filler material.

14. The converter assembly of claim 13, further comprising: Thin non-conductive substrate.

15. The converter assembly of claim 14, wherein the thin non-conductive substrate has a thickness in the range of greater than or equal to 10 micrometers to less than or equal to 200 micrometers, and / or wherein the converter layer has a thickness in the range of greater than or equal to 2 micrometers to less than or equal to 50 micrometers.

16. The converter assembly of claim 14, wherein the converter material particles are densely packed on the thin non-conductive substrate.

17. The converter assembly of claim 14, further comprising a reflective layer on the surface of the converter layer opposite to the thin non-conductive substrate.

18. The converter assembly of claim 14, wherein the thin non-conductive substrate comprises ceramic or glass, preferably the thin non-conductive substrate comprises ceramic, wherein the ceramic is a polycrystalline ceramic plate of phosphor material.

19. The converter assembly of claim 13, which is completely inorganic.

20. A light-emitting diode (LED) array, comprising: The mesa includes a stack of semiconductor layers, the semiconductor layers including active regions; and The converter assembly according to claim 13 is attached to the tabletop.

Images