Sidewall placement of light emitting diode devices and related methods

Abstract

A sidewall arrangement of a solid-state lighting device, more specifically, a light-emitting device such as a light-emitting diode (LED), is disclosed. The LED device (100) may include a light-modifying material disposed around the peripheral sidewall (102c) of the LED chip (102) without the need for a supporting submount or leadframe. The sidewall layers around the peripheral sidewall of the LED chip may include an inner layer (110) and an outer layer (112), each having different light-modifying properties. For example, the inner layer may be reflective to improve the light output and / or efficiency of the LED chip, while the outer layer may be absorptive to avoid interaction and / or crosstalk with adjacent LED chips. Having a reflective inner layer and an absorptive outer layer can improve light output, clarity, and contrast.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0001] This disclosure relates to solid-state lighting devices, and more particularly to sidewall arrangements of light-emitting devices such as light-emitting diodes (LEDs) and related methods. [Background technology]

[0002]

[0002] Solid-state lighting devices such as light-emitting diodes (LEDs) are increasingly being used in both consumer and commercial applications. Advances in LED technology have resulted in highly efficient, mechanically robust, and long-life light sources. Modern LEDs are therefore enabling a variety of new display applications and are increasingly being used in general lighting and automotive applications, often replacing incandescent and fluorescent light sources.

[0003]

[0003] LEDs are solid-state devices that convert electrical energy into light and typically contain one or more active layers (or active regions) of semiconductor material disposed between oppositely doped n-type and p-type layers. When a bias is applied across the doped layers, holes and electrons are injected into the active layer(s), where they recombine to produce light, such as visible or ultraviolet light. LED chips typically contain an active region, which may be fabricated from, for example, silicon carbide, gallium nitride, gallium phosphide, aluminum nitride, gallium arsenide-based materials, and / or organic semiconductor materials. Photons generated by the active region are emitted in all directions.

[0004]

[0004] It is typically desirable to operate LEDs at the highest possible light emitting efficiency, which can be measured in terms of luminous intensity (e.g., lumens per watt) relative to output power. A realistic goal for increasing light emitting efficiency is to maximize extraction of light emitted by the active region in the desired direction of light transmission. The light extraction and external quantum efficiency of an LED can be limited by several factors, including internal reflection. According to the well-understood meaning of Snell's Law, photons that reach a surface (interface) between the LED surface and the surrounding environment are either refracted or internally reflected. If photons are repeatedly internally reflected, they are eventually absorbed and do not provide any visible light exiting the LED.

[0005]

[0005] LED packages, modules, and fixtures have been developed that may include multiple LED emitters arranged in close proximity to one another. In such applications, the LED emitters can be provided such that the emissions corresponding to the individual LED emitters are combined to generate a desired emission. The emissions corresponding to the individual LED emitters can be selectively generated to provide similar or different emission characteristics. When different LED emitters are provided in close proximity to one another, it can be difficult to generate high-quality light with the desired emission characteristics. In addition, conventional LED emitter packaging can also result in spacing limitations between the individual LED emitters.

[0006]

[0006] The art continues to seek improved LED and solid state lighting devices with desirable lighting characteristics that can overcome the challenges associated with conventional lighting devices. Summary of the Invention [Means for solving the problem]

[0007]

[0007] The present disclosure relates to solid-state lighting devices, and more particularly to sidewall arrangements and related methods for light-emitting devices such as light-emitting diodes (LEDs). The LED device may include a light-modifying material sidewall arrangement around the peripheral sidewall of an LED chip without the need for a supporting submount or leadframe. The sidewall layers around the peripheral sidewall of the LED chip may include an inner layer and an outer layer, each having different light-altering properties. For example, the inner layer may be reflective to improve the light output and / or efficiency of the LED chip, while the outer layer may be absorptive to avoid interaction and / or crosstalk with adjacent LED chips. Having a reflective inner layer and an absorptive outer layer can improve light output, clarity, and contrast. Therefore, such an LED device may be well-suited for use in applications where the LED device forms a closely-spaced LED array. A manufacturing technique is disclosed that includes laminating multiple preformed sheets of light-modifying material onto one or more surfaces of the LED chip.

[0008] In one aspect, an LED device includes an LED chip having a top face and a bottom face. The LED device can also include a cover structure overlying the top face of the LED chip. The LED device can also include side layers surrounding at least the top and bottom faces of the LED chip, the side layers including an inner layer including a first light-modifying material having first light-modifying properties and an outer layer including a second light-modifying material having second light-modifying properties.

[0009] In an embodiment, each of the inner and outer layers of the side layers has a thickness of 15 microns (μm) to 100 μm.

[0010] In another embodiment, the thickness of the inner and outer layers can differ from one another.

[0010]

[0011] In embodiments, the thickness of the inner and outer layers of the side layers are selected based on a desired light-altering effect.

[0012] In an embodiment, the first light-altering property of the inner layer is reflective and the second light-altering property of the outer layer is absorptive.

[0011]

[0013] In another embodiment, the first light-altering property of the inner layer is reflective to a first range of wavelengths and non-reflective to a second range of wavelengths.

[0014] In another embodiment, the second light-altering property of the outer layer is absorptive to a first range of wavelengths and non-absorbent to a second range of wavelengths.

[0012]

[0015] In an embodiment, the LED device comprises a plurality of LED chips arranged on a surface, each LED chip of the plurality of LED chips comprising a respective side layer.

[0016] In an embodiment, the side layer also covers at least a portion of the side of the cover structure.

[0013]

[0017] In embodiments, the inner layer may be formed from at least one of a silicone material or an epoxy material.

[0018] In an embodiment, the outer layer of the side layer is formed from at least one of a silicone material or an epoxy material.

[0014]

[0019] In an embodiment, the cover structure comprises one or more of a lens structure or a layer comprising a lumiphoric material.

[0020] In an embodiment, the lens structure comprises a luminescent material.

[0015]

[0021] In an embodiment, the cover structure covers the top surface of the side layer.

[0022] In an embodiment, the cover structure has a larger lateral dimension than the LED chip, and the side layer surrounds both the LED chip and the cover structure.

[0016]

[0023] In an embodiment, the cover structure has a smaller lateral dimension than the LED chip, and the side layer surrounds both the LED chip and the cover structure.

[0024] In an embodiment, the top and bottom of the side layer are coplanar with the top surface of the LED chip and the bottom surface of the LED chip, respectively.

[0017]

[0025] In an embodiment, the top and bottom of the side layer are flush with the top surface of the cover structure and the bottom surface of the LED chip, respectively.

[0026] In an embodiment, the side layer covers the top surface of the LED chip.

[0018]

[0027] In an embodiment, the side layer covers the top surface of the cover structure.

[0028] In another aspect, a method can include providing an LED chip. The method can also include providing a cover structure on a top surface of the LED chip, the cover structure comprising one or more of a lens layer or a layer comprising a light-emitting material. The method can also include depositing a first layer comprising a material having reflective light-modifying properties on the top structure and on side surfaces of the LED chip. The method can also include depositing a second layer comprising a material having absorptive light-modifying properties on the first layer. The method can also include removing the first and second layers from at least a top of the cover structure, the first and second layers forming side layers surrounding at least the top and bottom surfaces of the LED chip.

[0019]

[0029] In another aspect, a method can include providing an LED chip. The method can also include providing a cover structure on a top surface of the LED chip, the cover structure comprising one or more of a lens layer or a layer comprising a light-emitting material. The method can also include depositing a first layer comprising a material having reflective light-modifying properties on the top surface of the cover structure and on a side surface of the LED chip. The method can also include removing the first layer from at least the top of the cover structure. The method can also include depositing a second layer comprising a material having absorptive light-modifying properties on the top of the cover structure and on the first layer on a side surface of the LED chip. The method can also include removing the second layer from at least the top of the cover structure, the first layer and the second layer forming side layers surrounding at least the top and bottom surfaces of the LED chip.

[0020]

[0030] In other aspects, any of the foregoing aspects may be used individually or together, and / or in combination with various individual aspects and features described herein to further advantage. Any of the various features and elements disclosed herein may be combined with one or more other disclosed features and elements, unless indicated to the contrary herein.

[0021]

[0031] Those skilled in the art will appreciate the scope of the present disclosure and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in conjunction with the accompanying drawings.

[0032] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate several aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure. [Brief explanation of the drawings]

[0022] [Figure 1]

[0033] FIG. 1A is a cross-sectional view of a light emitting diode (LED) device according to an embodiment disclosed herein.

[0034] Figure 1B is a top view of the LED device of Figure 1A. Figure 1C is a top view of the LED device of Figure 1A. [Figure 2]

[0035] FIG. 2 is a cross-sectional view of an LED device having a cover structure wider than the LED chip according to embodiments disclosed herein. [Figure 3]

[0036] FIG. 3 is a cross-sectional view of an LED device having an LED chip wider than the cover structure according to embodiments disclosed herein. [Figure 4]

[0037] FIG. 4 is a cross-sectional view of an LED device similar to that of FIG. 1A but with a cover structure having a different layer configuration according to an embodiment disclosed herein. [Figure 5]

[0038] FIG. 5 is a cross-sectional view of an LED device having a side layer surrounding a cover structure including a lens with an embedded conversion material according to embodiments disclosed herein. [Figure 6]

[0039] FIG. 6 is a cross-sectional view of an LED device having a side layer surrounding a cover structure including only a lens, according to an embodiment disclosed herein. [Figure 7]

[0040] FIG. 7 is a cross-sectional view of an LED device similar to FIG. 1A with a cover structure covering the top of the side layer according to embodiments disclosed herein. [Figure 8] FIG. 8 is a cross-sectional view of an LED device similar to FIG. 1A with a cover structure covering the top of the side layer according to embodiments disclosed herein. [Figure 9] FIG. 9 is a cross-sectional view of an LED device similar to FIG. 1A with a cover structure covering the top of the side layer according to embodiments disclosed herein. [Figure 10] FIG. 10 is a cross-sectional view of an LED device similar to FIG. 1A with a cover structure covering the top of the side layer according to embodiments disclosed herein. [Figure 11]

[0041] FIG. 11 is a cross-sectional view of an LED device having a different dome-shaped cover structure that is not surrounded by a side layer according to embodiments disclosed herein. [Figure 12] FIG. 12 is a cross-sectional view of an LED device having a different dome-shaped cover structure that is not surrounded by a side layer according to an embodiment disclosed herein. [Figure 13] FIG. 13 is a cross-sectional view of an LED device having a different dome-shaped cover structure that is not surrounded by a side layer according to an embodiment disclosed herein. [Figure 14] FIG. 14 is a cross-sectional view of an LED device having a different dome-shaped cover structure that is not surrounded by a side layer according to an embodiment disclosed herein. [Figure 15]

[0042] FIG. 15 is a cross-sectional view of an LED device having a different dome-shaped cover structure covering the top of the side layer according to an embodiment disclosed herein. [Figure 16] FIG. 16 is a cross-sectional view of an LED device having a different dome-shaped cover structure covering the top of the side layer according to an embodiment disclosed herein. [Figure 17] FIG. 17 is a cross-sectional view of an LED device having a different dome-shaped cover structure covering the top of the side layer according to an embodiment disclosed herein. [Figure 18] FIG. 18 is a cross-sectional view of an LED device having a different dome-shaped cover structure covering the top of the side layer according to an embodiment disclosed herein. [Figure 19]

[0043] FIG. 19 is a flowchart of a method for manufacturing an LED device according to embodiments disclosed herein. [Figure 20]

[0044] FIG. 20 is a flowchart of another method for manufacturing an LED device according to embodiments disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0023]

[0045] The embodiments set forth below represent the information necessary to enable one skilled in the art to practice the embodiments and illustrate the best ways to practice the embodiments. Upon reading the following description in conjunction with the accompanying drawings, one skilled in the art will understand the concepts of the present disclosure and will recognize applications of these concepts not specifically addressed herein. It is to be understood that these concepts and applications are within the scope of the present disclosure and the appended claims.

[0024]

[0046] As used herein, terms such as first, second, etc. may be used to describe various elements, but it will be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of the present disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0025]

[0047] When an element, such as a layer, region, or substrate, is referred to as being "on" or extending "over" another element, it will be understood that the element can be directly on or extending directly above the other element, or there may be intervening elements. In contrast, when an element is referred to as being "directly on" or extending "directly above" another element, there are no intervening elements. Similarly, when an element, such as a layer, region, or substrate, is referred to as being "above" or extending "over" another element, it will be understood that the element can be directly on or extending directly above the other element, or there may be intervening elements. In contrast, when an element is referred to as being "directly on" or extending "directly above" another element, there are no intervening elements. Also, when an element is referred to as being "connected" or "coupled" to another element, it will be understood that the element can be directly connected or coupled to the other element, or there may be intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

[0026]

[0048] Relative terms such as "bottom" or "top" or "upper" or "below" or "horizontal" or "vertical" may be used herein to describe the relationship of one element, layer, or region to another element, layer, or region, as illustrated in the figures. It will be understood that these terms, and those discussed above, are intended to encompass different orientations of the device in addition to the orientation shown in the figures.

[0027]

[0049] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. Furthermore, it will be understood that the terms "comprises," "comprising," "including," and / or "comprising," as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0028]

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Furthermore, terms used herein should be interpreted as having a meaning consistent with the meaning in the context of the present specification and related art, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0029]

[0051] Embodiments are described herein with reference to schematic diagrams of embodiments of the present disclosure. Accordingly, actual dimensions of layers and elements may vary, and variations from the shapes of the figures are expected, for example, as a result of manufacturing techniques and / or tolerances. For example, regions illustrated or described as square or rectangular may have rounded or curved features, and regions illustrated as straight lines may have slight irregularities. Accordingly, regions illustrated in the figures are schematic, and the shapes of those regions are not intended to illustrate the exact shape of a region of a device or to limit the scope of the disclosure. Additionally, the size of structures or regions may be exaggerated relative to other structures or regions for illustrative purposes and, therefore, are provided to illustrate the general structure of the inventive subject matter and may or may not be drawn to scale. Elements common between figures may be identified herein with common element numbers and may not be described again later.

[0030]

[0052] The present disclosure relates to solid-state lighting devices, and more particularly to sidewall arrangements and related methods for light-emitting devices such as light-emitting diodes (LEDs). The LED device may include a light-modifying material disposed around the peripheral sidewall of an LED chip without the need for a supporting submount or leadframe. The sidewall layers around the peripheral sidewall of the LED chip may include an inner layer and an outer layer, each having different light-modifying properties. For example, the inner layer may be reflective to improve the light output and / or efficiency of the LED chip, while the outer layer may be absorptive to avoid interaction and / or crosstalk with adjacent LED chips. Having a reflective inner layer and an absorptive outer layer can improve light output, clarity, and contrast. Therefore, such an LED device may be well suited for use in applications where the LED devices form a densely packed LED array. A manufacturing technique is disclosed that includes laminating multiple preformed sheets of light-modifying material onto one or more surfaces of the LED chip.

[0031]

[0053] An LED chip typically includes an active LED structure or region that can have many different semiconductor layers arranged in different ways. The fabrication and operation of LEDs and their active structures are generally known in the art and will be briefly discussed herein. The layers of the active LED structure can be fabricated using known processes, with a suitable process being fabrication using metal organic chemical vapor deposition. The layers of the active LED structure can include many different layers and generally include an active layer sandwiched between n-type and p-type oppositely doped epitaxial layers, all formed in sequence on a growth substrate. It is understood that the active LED structure can also include additional layers and elements, such as, but not limited to, buffer layers, nucleation layers, superlattice structures, undoped layers, cladding layers, contact layers, current-spreading layers, light extraction layers, and elements. The active layer may comprise a single quantum well, multiple quantum wells, a double heterostructure, or a super lattice structure.

[0032]

[0054] Active LED structures can be fabricated from different material systems, some of which are Group III nitride-based. Group III nitrides refer to semiconductor compounds formed between nitrogen (N) and elements from Group III of the periodic table, usually aluminum (Al), gallium (Ga), and indium (In). Gallium nitride (GaN) is a common binary compound. Group III nitrides also refer to ternary and quaternary compounds such as aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), and aluminum indium gallium nitride (AlInGaN). For Group III nitrides, silicon (Si) is a common n-type dopant, and magnesium (Mg) is a common p-type dopant. Thus, the active, n-type, and p-type layers may include one or more layers of GaN, AlGaN, InGaN, and AlInGaN, undoped or doped with Si or Mg, in the case of Group III nitride-based material systems. Other material systems include silicon carbide (SiC), organic semiconductor materials, and other III-V systems such as gallium phosphide (GaP), gallium arsenide (GaAs), and related compounds.

[0033]

[0055] Active LED structures may be grown on growth substrates, which can include many materials such as sapphire, SiC, aluminum nitride (AlN), and GaN, with the preferred substrate being the 4H polytype of SiC. However, other SiC polytypes, including the 3C, 6H, and 15R polytypes, can also be used. SiC offers certain advantages, such as a closer crystal lattice match to III-nitrides than other substrates, resulting in high-quality III-nitride films. SiC also has very high thermal conductivity, so the total output power of III-nitride devices on SiC is not limited by the thermal dissipation of the substrate. Sapphire is another common substrate for III-nitrides and offers certain advantages, such as low cost, an established manufacturing process, and excellent optical properties for light transmission.

[0034]

[0056] Different embodiments of the active LED structure can emit light of different wavelengths depending on the composition of the active layer, n-type layer, and p-type layer. In some embodiments, the active LED structure emits blue light with a peak wavelength range of about 430 nanometers (nm) to 480 nm. In other embodiments, the active LED structure emits green light with a peak wavelength range of 500 nm to 570 nm. In other embodiments, the active LED structure emits red light with a peak wavelength range of 600 nm to 650 nm.

[0035]

[0057] The LED chip may also be coated with one or more luminescent materials (also referred to herein as phosphors), such as phosphors, so that at least a portion of the light from the LED chip is absorbed by one or more luminescent materials and converted to one or more different wavelength spectra according to the characteristic emission from the one or more luminescent materials. In this regard, the at least one luminescent material that receives at least a portion of the light generated by the LED light source may re-emit light having a different peak wavelength than the LED light source. The LED light source and one or more luminescent materials may be selected so that their combined output results in light having one or more desired characteristics, such as color, color point, intensity, etc. In certain embodiments, the collective emission of the LED chip, optionally in combination with one or more luminescent materials, may be arranged to provide cool white, neutral white, or warm white light, such as within a color temperature range of 2500 K to 10,000 K. In certain embodiments, luminescent materials having peak wavelengths of cyan, green, amber, yellow, orange, and / or red may be used. In some embodiments, the LED chip in combination with one or more light emitters (e.g., phosphors) emits a nearly white light combination. The one or more phosphors may be yellow (e.g., YAG:Ce), green (e.g., LuAg:Ce), and red (e.g., Ca i-x-y Sr x EU yAlSiN3) light-emitting phosphors, and combinations thereof.

[0036]

[0058] The luminescent materials described herein may be or include one or more of phosphors, scintillators, luminescent inks, quantum dot materials, day glow tape, etc. The luminescent materials may be provided by any suitable means, such as, for example, directly coated on one or more surfaces of an LED, dispersed in an encapsulant material configured to cover one or more LEDs, and / or coated on one or more optical or support elements (e.g., by powder coating, inkjet printing, etc.). In certain embodiments, the luminescent materials may be downconverted or upconverted, or a combination of both downconverting and upconverting materials may be provided. In certain embodiments, multiple different (e.g., compositionally different) luminescent materials arranged to produce different peak wavelengths may be arranged to receive emitted light from one or more LED chips. The one or more luminescent materials may be provided on one or more portions of the LED chip in various configurations. In certain embodiments, one or more surfaces of an LED chip may be conformally coated with one or more luminescent materials, while other surfaces of such an LED chip may be free of luminescent materials. In certain embodiments, the top surface of the LED chip may include a luminescent material, while one or more side surfaces of the LED chip may be free of luminescent material. In certain embodiments, all or substantially all outer surfaces of the LED chip (e.g., other than the contact-defining or mounting surface) are coated or covered with one or more luminescent materials. In certain embodiments, the one or more luminescent materials may be disposed in a substantially uniform manner on or above one or more surfaces of the LED chip. In other embodiments, the one or more luminescent materials may be disposed in a non-uniform manner with respect to one or more of material composition, concentration, and thickness on or above one or more surfaces of the LED chip.In certain embodiments, the fill factor of one or more luminescent materials may vary on or between one or more outer surfaces of the LED chip. In certain embodiments, one or more luminescent materials may be patterned on a portion of one or more surfaces of the LED chip to include one or more stripes, dots, curves, or polygonal shapes. In certain embodiments, multiple luminescent materials may be disposed in different discrete regions or layers on or above the LED chip.

[0037]

[0059] In certain embodiments, one or more luminescent materials may be provided as at least a portion of a wavelength conversion element. The wavelength conversion element may include a support element, such as a superstrate, and one or more luminescent materials provided by any suitable means, such as coating the surface of the superstrate or incorporating it within the superstrate. As used herein, the term “superstrate” refers to an element disposed on or above the LED chip, which may include the luminescent material. The term “superstrate” is used herein to avoid confusion with other substrates that may be part of a semiconductor light-emitting device, such as the growth substrate or carrier substrate of an LED chip or the submount of an LED package. The term “superstrate” is not intended to limit the orientation, location, and / or composition of the structure it represents. In some embodiments, the superstrate may be composed of a transparent material, a semi-transparent material, or an optically transmissive material such as sapphire, SiC, silicone, and / or glass (e.g., borosilicate and / or fused silica). The overlayer may be patterned to enhance light extraction, as described in commonly owned U.S. Patent Application Publication No. 2019 / 0326484, entitled "Semiconductor Light Emitting Devices Including Superstrates with Patterned Surfaces," which is incorporated herein by reference. The overlayer may be configured as described in commonly owned U.S. Patent Application Publication No. 2018 / 0033924, which is also incorporated herein by reference. The overlayer may be formed from a bulk substrate that is optionally patterned and then singulated. In certain embodiments, patterning of the overlayer may be performed by an etching process (e.g., wet etching or dry etching). In certain embodiments, patterning of the overlayer may be performed by otherwise modifying the surface, such as with a laser or a saw. In certain embodiments, the overlayer may be thinned before or after performing the patterning process.In certain embodiments, the top layer may have a substantially planar top surface that corresponds to the light emitting area of ​​the LED package.

[0038]

[0060] One or more luminescent materials may be disposed on the upper layer, for example, by spraying and / or coating the luminescent material onto the upper layer. The wavelength converting element may be attached to one or more LED chips, for example, using a layer of transparent adhesive. In certain embodiments, the layer of transparent adhesive may include silicone having a refractive index ranging from about 1.3 to about 1.6, which is lower than the refractive index of the LED chip on which the wavelength converting element is disposed. In other embodiments, the wavelength converting element may have an alternative configuration, such as a phosphor-in-glass or ceramic phosphor plate arrangement. A phosphor-in-glass or ceramic phosphor plate arrangement may be formed by mixing phosphor particles with a glass frit or ceramic material, pressing the mixture into a planar shape, and firing or sintering the mixture to form a hardened structure that can be cut or separated into individual wavelength converting elements.

[0039]

[0061] Light emitted from the active layer or region of the LED chip is emitted in all directions. For directional applications, an internal mirror or external reflective surface may be applied to redirect as much light as possible in the desired direction of emission. The internal mirror may include single or multiple layers. Some multilayer mirrors include a metallic reflective layer and a dielectric reflective layer, with the dielectric reflective layer disposed between the metallic reflective layer and multiple semiconductor layers. A passivation layer is disposed between the metallic reflective layer and first and second electrical contacts, with the first electrical contact disposed in conductive electrical communication with the first semiconductor layer and the second electrical contact disposed in conductive electrical communication with the second semiconductor layer. For single-layer or multilayer mirrors that include surfaces with reflectivity less than 100%, some light may be absorbed by the mirror. Additionally, light redirected through the active LED structure may be absorbed by other layers or elements within the LED chip.

[0040]

[0062] As used herein, a layer or region of a light-emitting device may be considered “transparent” if at least 80% of the light emitted that strikes the layer or region passes through the layer or region and emerges. Additionally, as used herein, a layer or region of an LED may be considered “reflective” or embody a “mirror” or “reflector” if at least 80% of the light emitted that strikes the layer or region is reflected. In some embodiments, the light emitted comprises visible light, such as blue and / or green LEDs, with or without a light-emitting material. In other embodiments, the light emitted may comprise non-visible light. For example, in the case of GaN-based blue and / or green LEDs, silver (Ag) may be considered a reflective material (e.g., at least 80% reflective). In the case of ultraviolet (UV) LEDs, appropriate materials may be selected to achieve a desired, in some embodiments, high reflectivity and / or a desired, in some embodiments, low absorption. In certain embodiments, a “light-transmitting” material may be configured to transmit at least 50% of the light emitted at a desired wavelength.

[0041]

[0063] The present disclosure may be useful for LED chips having various geometries, such as vertical and horizontal geometries. Vertically shaped LED chips typically include anode and cathode connections on opposite sides or faces of the LED chip. Horizontally shaped LED chips typically include both anode and cathode connections on the same side of the LED chip opposite a substrate, such as a growth substrate. In certain embodiments, horizontally shaped LED chips may be arranged for flip-chip mounting to another surface.

[0042]

[0064] The embodiments disclosed herein may be useful for LED modules, systems, or fixtures that include closely spaced LED emitters or devices that can provide both an overall combined light emission and some modifiable, selectable, or tunable light emission characteristics provided by individually controlling the LED devices. In this manner, the LED devices are placed as close together as possible so that they appear as a single light-emitting area when all are electrically activated. However, if different light emission characteristics are desired, specific LED devices or groups of closely spaced LED devices may be individually electrically activated or deactivated. In such applications, size and space constraints make it impractical to use separately packaged LEDs. Conventional LED packages typically include an LED chip mounted on a larger submount and an encapsulant surrounding the LED chip on the submount, resulting in a larger footprint for the LED package compared to the LED chip. Additionally, conventional LED packages may include multiple LED chips arranged on a common substrate (e.g., a ceramic panel) or leadframe package. However, this also increases the package footprint to accommodate the common substrate or leadframe. This increased footprint may be undesirable for manufacturers wanting to build pixelated lighting systems, such as those used for adaptive automotive headlights or display applications.

[0043]

[0065] According to embodiments disclosed herein, LED devices are provided with reduced footprints that enable the assembly of densely packed arrays of LED devices on a common support, such as a printed circuit board (RCB). The LED devices disclosed herein may be manufactured without conventional submounts and leadframes, which contribute to an increased footprint. In certain embodiments, LED devices that can be mounted to external electrical connections, such as those provided on a PCB, without using conventional submounts and leadframes may be referred to as chip-scale packages (CSPs). In this regard, a CSP may include one or more elements, such as a light-emitting material, an encapsulant, a light-modifying material, a lens, and electrical contacts, and one or more LED chips are provided without a conventional submount or leadframe. For densely packed applications, the LED device (e.g., a CSP) may be configured to avoid interactions or crosstalk that may occur due to leakage of light emission from adjacent LED devices. In this regard, the LED devices disclosed herein may be configured with a footprint that approximates the footprint of the LED chip within the LED device, while also providing a certain amount of light-modifying material around the peripheral edges of the LED chip to reduce crosstalk.

[0044]

[0066] As used herein, light-modifying materials may include many different materials, including light-reflective materials that reflect or redirect light, light-absorbing materials that absorb light, and materials that act as thixotropic agents. As used herein, the term "light-reflective" refers to materials or particles that reflect, refract, or redirect light. For light-reflective materials, the light-modifying material may include at least one of fused silica, fumed silica, titanium dioxide (TiO), or metal particles suspended in a binder such as silicone or epoxy. For light-absorbing materials, the light-modifying material may include at least one of carbon, silicon, or metal particles suspended in a binder such as silicone or epoxy. Light-reflective and light-absorbing materials may comprise nanoparticles. In certain embodiments, the light-modifying material may have a substantially white color to reflect and redirect light. In other embodiments, the light-modifying material may have a substantially opaque, i.e., black, color to absorb light and enhance contrast.

[0045]

[0067] In certain embodiments, the light-modifying material includes both a light-reflective material and a light-absorbing material suspended in a binder. The weight ratio of the light-reflective material to the binder may range from about 1:1 to about 2:1. The weight ratio of the light-absorbing material to the binder may range from about 1:400 to about 1:10. In certain embodiments, the total weight of the light-modifying material includes any combination of the binder, the light-reflective material, and the light-absorbing material. In some embodiments, the binder may comprise a weight percentage ranging from about 10% to about 90% of the total weight of the light-modifying material. The light-reflective material may comprise a weight percentage ranging from about 10% to about 90% of the total weight of the light-modifying material. The light-absorbing material may comprise a weight percentage ranging from about 0% to about 15% of the total weight of the light-modifying material.

[0046]

[0068] In further embodiments, the light absorbing material may comprise a weight percent in the range of greater than about 0% to about 15% of the total weight of the light modifying material. In further embodiments, the binder may comprise a weight percent in the range of about 25% to about 70% of the total weight of the light modifying material. The light reflective material may comprise a weight percent in the range of about 25% to about 70% of the total weight of the light modifying material. The light absorbing material may comprise a weight percent in the range of about 0% to about 5% of the total weight of the light modifying material. In further embodiments, the light absorbing material may comprise a weight percent in the range of about greater than about 0% to about 5% of the total weight of the light modifying material.

[0047]

[0069] In certain embodiments, the light-modifying material may be provided in a preformed sheet or layer including light-modifying particles suspended in a binder. For example, the light-modifying particles may be suspended in a non-fully cured silicone binder to provide a preformed sheet of light-modifying material. A doctor blade or the like may be moved across the sheet to achieve the desired thickness or height of the preformed sheet. The preformed sheet may then be placed over and subsequently formed around the LED chip and / or wavelength-converting element overlying the LED chip. For example, the preformed sheet may be laminated around the LED chip and / or wavelength-converting element, after which the preformed sheet may be fully cured in place. One or more portions of the preformed sheet may then be removed from the primary light-emitting surface of the LED chip and / or wavelength-converting element. In this manner, light-modifying material may be formed along the peripheral edges or sidewalls of the LED chip and wavelength-converting element at thicknesses previously not possible with conventional dispensing techniques typically used to form light-modifying materials. Additionally, the light-modifying material may be provided without the need for a conventional submount or lead frame as support for conventional dispensing and / or molding techniques. In this regard, LED devices having the light-modifying material may be provided in a reduced footprint suitable for densely packed LED placement.

[0048]

[0070] In certain applications, LED devices as disclosed herein may be well-suited for dense array applications such as automotive lighting, general lighting, and illuminated displays. For automotive exterior lighting, multiple LED devices may be arranged under a common lens or optics to provide a single overall light emission or light emission that can be changed between different light emission characteristics. Changing light emission characteristics may include switching between high and low beam light emission, adaptively changing light emission, and adjusting the correlated color temperature (CCT) to accommodate daytime and nighttime driving conditions. For general lighting applications, LED devices disclosed herein may be configured to provide modules, systems, and fixtures capable of providing one or more different light emission colors or CCT values, such as one or more of warm white (e.g., 2700 Kelvin (K) to 3000 K), neutral white (e.g., 3500 K to 4500 K), and cool white (5000 K to 6500 K). For horticulture lighting applications, the LED devices disclosed herein may be arranged to provide modules, systems, and fixtures that can be modified to provide different light emission characteristics targeted to various growing conditions of different crops.

[0049]

[0071] FIG. 1A is a cross-sectional view of an LED device 100 according to an embodiment disclosed herein. The LED device 100 includes an LED chip 102, and the LED device 100 lacks the submount and / or leadframe typically found in conventional LED packages. In this regard, the LED device 100 may be referred to as a CSP. While FIG. 1A illustrates a single LED chip 102, the LED device 100 may include multiple LED chips 102 without departing from the principles disclosed herein. The LED chip 102 may include a top surface 102a, a bottom surface 102b, and peripheral sidewalls 102c surrounding the top surface 102a and the bottom surface 102b. As an example, for a square or rectangular area of ​​the top surface 102a and the bottom surface 102b, the LED chip 102 may include four peripheral sidewalls 102c. In certain embodiments, the LED device 10 may include a cover structure 108 including a lens 106 and a conversion layer 104 comprising a light-emitting material. The lens 106 may comprise a material that is optically transmissive and / or transparent to the light emitted by the LED chip 102 and the light converted by the conversion layer 104. The lens 106 may be textured to improve light extraction or include materials such as phosphors or scattering particles. The conversion layer 104 may be composed of any of the materials described above, including one or more phosphors that provide the same or different light-emitting characteristics. In certain embodiments, the lens 106 and conversion layer 104 may be attached to the LED chip 102 using, for example, a layer of transparent adhesive, such as silicone. In certain embodiments, the conversion layer 104 is formed between the lens 106 and the LED chip 102, thereby protecting the conversion layer 104 from environmental exposure.

[0050]

[0072] 1A , a side layer 114 is provided around and / or on the peripheral sidewall 102c of the LED chip 102. The side layer 114 may be provided around and / or on the peripheral side of the cover structure 108. As described above and in more detail below, the side layer 114 may be formed by a lamination process. The side layer 114 may comprise an inner layer 110 and an outer layer 112, each of which provides different light-modifying properties.

[0051]

[0073] In certain embodiments, the thickness of each of the inner layer 110 and the outer layer 112 is in the range including 15 microns (μm) and 100 μm, or in the range including 15 μm and 60 μm, or in the range including 15 μm and 50 μm, or in the range including 20 μm and 50 μm. Such thicknesses may be configured differently for different dimensions of the LED chip 102 or based on different desired light-modifying effects.

[0052]

[0074] 1A , the side layer 114 may be formed to conform to the peripheral sidewall 102c of the LED chip 102 and the peripheral side surfaces of the conversion layer 104 and lens 106 of the cover structure 108. In this regard, the thickness of the side layer 114 may be the same for both the peripheral sidewall 102c of the LED chip 102 and the peripheral side surfaces of the cover structure 108, with a curved transition therebetween. In addition, the top surfaces of the inner layer 110 and the outer layer 112 may be disposed to be flush or substantially flush with the top surface of the cover structure 108. In this manner, the top surface of the cover structure 108 forms the primary light-emitting surface of the LED device 100. The LED device 100 may further include a cathode contact 116 and an anode contact 120 disposed on the bottom surface 102b of the LED chip 102 in a flip-chip arrangement. The bottom surfaces of the inner layer 110 and the outer layer 112 may be flush with the bottom surface 102b of the LED chip 102, or may be flush with the bottom surfaces of the cathode contact 116 and the anode contact 120. With this arrangement, the cathode contact 116 and the anode contact 120 may be configured for direct mounting with external electrical connections, such as electrical traces on a PCB.

[0053]

[0075] In one or more embodiments, the side layer 114 may cover the top surface 102a of the LED chip 102, or may also cover the top surface or top side of the cover structure 108. In this manner, the overall light output of the LED chip 102 may be modified depending on the light-modifying properties of the inner layer 110 and the outer layer 112.

[0054]

[0076] In embodiments, the inner layer 110 and the outer layer 112, which form the side layer 114, can comprise silicone or epoxy. By embedding different light-modifying materials into the inner layer 110 and the outer layer 112, the type of light-modifying effect (reflective vs. absorptive) or the magnitude of the effect can be tailored. In various embodiments, the light-modifying properties can be selective to the wavelengths for which they are effective. For example, the inner layer 110 can be reflective to a first range of wavelengths of light and transparent to a second range of wavelengths, i.e., highly transmissive and less reflective. Examples of light-modifying materials that can be added to the inner layer 110 and the outer layer 112 include zirconia or alumina for increased reflectivity, while carbon black can be added for increased absorption. Chromium particles can be added as a pseudo-filter to increase the reflectivity of certain wavelengths while allowing other wavelengths to pass. Other light-modifying materials are possible as well. The thickness of the inner layer 110 and the outer layer 112, as well as the density of the embedded light-modifying material, can be tailored based on the desired light-modifying effect. For example, if contrast and reduced interference are most important, the outer layer 112 can be thicker than the inner layer 110, and a higher density of absorptive light-modifying material can be added to the outer layer 112. On the other hand, if increased light output is more important, the inner layer 110 can be thicker relative to the outer layer 112, and a higher density of reflective light-modifying material can be added within the inner layer 110.

[0055]

[0077] Figure 1B is a top view of the LED device 100 of Figure 1A. As illustrated, an inner layer 110 and an outer layer 112 are disposed around the cover structure 108.

[0078] 1C is another top view of the LED device 100 of FIG. 1A, but on a device with multiple LED chips 102. The LED chips 102 can be formed into an array, and the side layer 114 and cover structure 108 around each LED chip 102 can reduce interference and crosstalk between the LED chips 102, resulting in improved contrast, control of the light emission pattern, and improved output.

[0056]

[0079] 2 illustrates a cross-sectional view of an LED device 100 having a cover structure that is wider than the LED chip 102 according to embodiments disclosed herein. The lens 106 and conversion layer 104 can extend beyond the peripheral sidewalls of the LED chip 102, and the inner layer 110 and outer layer 112 can conform to the sidewalls of the cover structure and the LED chip 102. The arrangement of FIG. 2 may be advantageous for allowing for slight lateral misalignment when the cover structure is attached to the LED chip 102. A similar but opposite embodiment, in which the width of the LED chip 102 is wider than the width of the lens 106 and conversion layer 104, is illustrated in FIG. 3.

[0057]

[0080] In embodiments, the inner layer 110 and the outer layer 112 can have right-angled corners to accommodate the width difference between the LED chip 102 and the cover structure, as illustrated in Figures 2 and 3. However, in other embodiments, the inner layer 110 and / or the outer layer 112 can have more gradual or curved angles.

[0058]

[0081] Figure 4 is a cross-sectional view of an LED device similar to that of Figure 1A but with a cover structure having a different layer configuration, according to an embodiment disclosed herein. Figure 4 differs from the embodiment shown in Figure 1A in that instead of the conversion layer 104 being adjacent to the LED chip 102, in Figure 4 the lens 106 of the cover structure is adjacent to the top surface of the LED chip 102, and the conversion layer 104 is above the lens 106.

[0059]

[0082] In Figure 5, the cover structure includes only a single layer 105, which is a lens with an embedded conversion layer or a lens containing a luminescent material. In contrast, in the embodiment depicted in Figure 6, the LED device 100 includes a cover structure comprising only a lens 106 without a conversion layer 104. In each of the various embodiments illustrated in Figures 1A and 2-6, the tops of the inner and outer layers 110 and 112 are flush with the top of the cover structure, while the bottoms of the inner and outer layers 110 and 112 are flush with the bottoms of the LED chip 102 or cathode 116 and anode 114.

[0060]

[0083] 7-10 depict cross-sectional views of LED devices similar to FIG. 1A, in which a cover structure covers the top of the side layer 114, according to embodiments disclosed herein.

[0084] In the embodiment depicted in Figure 7, the conversion layer 104 is above the lens 106, covering both the lens 102 and the top surfaces of the inner layer 110 and outer layer 112. Figure 8 depicts an alternative embodiment to Figure 7 in which the layers of the cover structure 108 are swapped, with the conversion layer 104 adjacent to the lens 102 and the lens 106 positioned above the conversion layer 104.

[0061]

[0085] In the embodiment depicted in Figure 9, a layer 105 comprising lenses with embedded luminescent material covers both the lenses 102 and the top surfaces of the inner layer 110 and outer layer 112. Figure 10 depicts an alternative embodiment to Figure 9 in which a single lens 106 covers the top surface of the lenses 102 and the top surfaces of the inner layer 110 and outer layer 112.

[0062]

[0086] 11-14 depict cross-sectional views of LED devices having different dome-shaped cover structures that are not surrounded by side layers according to embodiments disclosed herein.

[0087] 11, the dome-shaped lens layer 106 covers the conversion layer 104, which covers the LED chip 102 but does not cover the inner layer 110 and outer layer 112 of the side layer 114. The top surfaces of the inner layer 110 and outer layer 112 are flush with the top surface of the conversion layer 104.

[0063]

[0088] 12, the dome-shaped lens 106 covers the LED chip 102 but does not cover the inner layer 110 and outer layer 112 of the side layer 114. The top surfaces of the inner layer 110 and outer layer 112 are flush with the top surface of the LED chip 102. In addition, the conversion layer 104 is provided on the top surface of the dome-shaped lens 106.

[0064]

[0089] In FIG. 13, a dome-shaped layer 105 with a lens embedded with luminescent material covers the LED chip 102 while the top surfaces of the inner layer 110 and outer layer 112 are flush with the top surface of the LED chip 102.

[0065]

[0090] In FIG. 14, the dome-shaped lens 106 covers the LED chip 102 while the top surfaces of the inner layer 110 and outer layer 112 are flush with the top surface of the LED chip 102 .

[0066]

[0091] 15-18 depict cross-sectional views of LED devices with different dome-shaped cover structures covering the top of the side layer according to embodiments disclosed herein.

[0092] FIG. 15 depicts an LED device similar to that illustrated in FIG. 11, except that in FIG. 15, a dome-shaped lens 106 covers the top surfaces of inner layer 110 and outer layer 112.

[0067]

[0093] FIG. 16 depicts an LED device similar to that shown in FIG. 12, except that in FIG. 16, a dome-shaped lens 106 covers the top surfaces of the inner layer 110 and the outer layer 112, while a conversion layer 104 is provided on the top surface of the dome-shaped lens 106.

[0068]

[0094] FIG. 17 depicts an LED device similar to that shown in FIG. 13, except that in FIG. 17 a dome-shaped layer 105 comprising a lens with embedded luminescent material covers the upper surfaces of inner layer 110 and outer layer 112.

[0069]

[0095] FIG. 18 depicts an LED device similar to that illustrated in FIG. 14, except that in FIG. 18, a dome-shaped lens 106 covers the top surfaces of inner layer 110 and outer layer 112.

[0070]

[0096] 19 is a flowchart of a method for fabricating LED devices similar to those depicted in FIGS. 1A-1C and 2-18 according to embodiments disclosed herein. In an embodiment, a typical method of fabrication involves the die being attached to tape, covered with a lens, and a silicone or epoxy sheet containing reflective and absorbing materials laminated under vacuum, after which the sheet is removed without damaging the sidewalls to expose the lens, covering the package design so that the die can then be singulated into low-footprint CSPs.

[0071]

[0097] The method may begin at step 1902 with providing an LED chip. The LED chip may be one of multiple LED chips formed together.

[0072]

[0098] In step 1904, the method comprises providing a cover structure on the top surface of the LED chip, the cover structure comprising one or more of a lens layer (e.g., lens 106) or a layer comprising a light-emitting material. The layer comprising a light-emitting material can be the conversion layer 104 described above.

[0073]

[0099] In step 1906, the method includes depositing a first layer comprising a material having reflective light-altering properties on the top structure and sides of the LED chip. The first layer can be the inner layer 110.

[0074]

[0100] In step 1908, the method includes laminating a second layer comprising a material having absorptive light-altering properties onto the first layer. The second layer is the outer layer 112. The first and second layers can each have a thickness ranging from 15 microns (μm) to 100 μm. Additionally, the first and second layers can be composed of silicone or epoxy. The epoxy matrix used to manufacture the layers can include fibers to reinforce the layers. During the lamination process of the first and second layers, the layer sheet can be placed on a lamination tool and placed on pegs above a hot plate. The tool is then evacuated to press the sheet against the die, giving the sidewalls a conformal shape. The pegs then lower the part onto the hot plate, allowing the sheet to harden.

[0075]

[0101] In step 1910, the method includes removing the first and second layers from at least the top of the cover structure, the first and second layers forming side layers surrounding at least the top and bottom surfaces of the LED chip. The removal process can be performed by abrasion and / or polishing, where the polishing tool is configured to remove only the sheet of material laminated on the lens.

[0076]

[0102] FIG. 20 is a flowchart of another method for fabricating an LED device similar to the LED devices depicted in FIGS. 1A-1C and 2-18 according to embodiments disclosed herein.

[0077]

[0103] The method may begin at step 2002 with providing an LED chip.

[0104] In step 2004, the method includes providing a cover structure on the top surface of the LED chip, the cover structure comprising one or more of a lens layer or a layer comprising a light-emitting material.

[0078]

[0105] In step 2006, the method includes depositing a first layer comprising a material having reflective light-altering properties onto the top surface of the cover structure and onto the side of the LED chip.

[0079]

[0106] In step 2008, the method includes removing the first layer from at least the top of the cover structure.

[0107] In step 2010, the method includes laminating a second layer comprising a material having absorptive light-altering properties onto the top of the cover structure and onto the first layer on the sides of the LED chip.

[0080]

[0108] In step 2012, the method includes removing the second layer from at least the top of the cover structure, the first layer and the second layer forming side layers surrounding at least the top and bottom surfaces of the LED chip.

[0081]

[0109] 1A and 2-6, the method steps in Figures 19-20 create an LED device in which the tops of the inner layer 110 and outer layer 112 are flush with the top of the cover structure. In the embodiment depicted in Figures 7-18, the top surfaces of the inner layer 110 and outer layer 112 are flush with the top surface of the LED chip 102, but the method in Figures 19-20 can be modified by forming and removing the first and second layers before the lens 106 or conversion layer 104 is attached to the top of the LED chip 102.

[0082]

[0110] It is contemplated that any of the foregoing aspects and / or various individual aspects and features described herein may be combined to further advantage. Any of the various embodiments disclosed herein may be combined with one or more of the other disclosed embodiments, unless indicated to the contrary herein.

[0083]

[0111] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure, and all such improvements and modifications are considered to be within the scope of the concepts disclosed herein and the scope of the appended claims.

Claims

1. 1. A light emitting diode (LED) device comprising: an LED chip having a top surface and a bottom surface; a cover structure covering the upper surface of the LED chip; a side layer surrounding at least the top and bottom surfaces of the LED chip, the side layer comprising an inner layer comprising a first light-modifying material having first light-modifying properties and an outer layer comprising a second light-modifying material having second light-modifying properties; and An LED device comprising:

2. 10. The LED device of claim 1, wherein the inner and outer layers of the side layers each have a thickness of 15 microns (μm) to 100 μm.

3. 3. The LED device of claim 2, wherein the thickness of the inner layer is different from the thickness of the outer layer.

4. 3. The LED device of claim 2, wherein the thicknesses of the inner and outer layers of the side layers are selected based on a predetermined light-modifying effect.

5. 10. The LED device of claim 1, wherein the first light-altering property of the inner layer is reflective and the second light-altering property of the outer layer is absorptive.

6. 6. The LED device of claim 5, wherein the first light-altering property of the inner layer is reflective to a first range of wavelengths and non-reflective to a second range of wavelengths.

7. 6. The LED device of claim 5, wherein the second light-altering property of the outer layer is absorptive for a first range of wavelengths and non-absorbent for a second range of wavelengths.

8. 10. The LED device of claim 1, wherein the LED device comprises a plurality of LED chips disposed on a surface, each LED chip of the plurality of LED chips comprising a respective side layer.

9. The LED device of claim 1 , wherein the side layer also covers at least a portion of a side surface of the cover structure.

10. 10. The LED device of claim 1, wherein the inner layer of the side layer is formed from at least one of a silicone material or an epoxy material.

11. 10. The LED device of claim 1, wherein the outer layer of the side layer is formed from at least one of a silicone material or an epoxy material.

12. 10. The LED device of claim 1, wherein the cover structure comprises one or more of a lens structure or a layer comprising a light-emitting material.

13. 13. The LED device of claim 12, wherein the lens structure comprises the luminescent material.

14. The LED device of claim 1 , wherein the cover structure covers an upper surface of the side layer.

15. 10. The LED device of claim 1, wherein the cover structure has a lateral dimension greater than that of the LED chip, and the side layer surrounds both the LED chip and the cover structure.

16. 10. The LED device of claim 1, wherein the cover structure has smaller lateral dimensions than the LED chip, and the side layer surrounds both the LED chip and the cover structure.

17. 10. The LED device of claim 1, wherein the upper and lower sides of the side layers are flush with the top surface of the LED chip and the bottom surface of the LED chip, respectively.

18. 10. The LED device of claim 1, wherein the upper and lower sides of the side layer are flush with the top surface of the cover structure and the bottom surface of the LED chip, respectively.

19. The LED device of claim 1 , wherein the side layer covers the top surface of the LED chip.

20. The LED device of claim 1 , wherein the side layer covers a top surface of the cover structure.

21. Providing a light emitting diode (LED) chip; providing a cover structure on a top surface of the LED chip, the cover structure comprising one or more of a lens layer or a layer comprising a light-emitting material; depositing a first layer comprising a material having reflective light-altering properties onto the upper structure and side surfaces of the LED chip; depositing a second layer comprising a material having absorptive light-altering properties onto the first layer; removing the first layer and the second layer from at least a top portion of the cover structure, the first layer and the second layer forming side layers surrounding at least the top and bottom surfaces of the LED chip; A method comprising:

22. Providing a light emitting diode (LED) chip; providing a cover structure on a top surface of the LED chip, the cover structure comprising one or more of a lens layer or a layer comprising a light-emitting material; depositing a first layer comprising a material having reflective light-altering properties on a top surface of the cover structure and on a side surface of the LED chip; removing the first layer from at least the top portion of the cover structure; depositing a second layer comprising a material having absorptive light-altering properties on top of the cover structure and on the first layer on the side of the LED chip; removing the second layer from at least the top of the cover structure, the first layer and the second layer forming side layers surrounding at least the top and bottom surfaces of the LED chip; A method comprising:

Images