Patent Publication Number: US-11652134-B2

Title: Monolithic segmented LED array architecture

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/226,604 filed Dec. 19, 2018 (now U.S. Pat. No. 11,355,548), which claims (i) benefit of U.S. Provisional Application No. 62/608,516 filed Dec. 20, 2017 and (ii) priority of Application No. EP 18158961.5 filed Feb. 27, 2018; each of those applications is incorporated by reference as if set forth herein in its entirety. 
    
    
     BACKGROUND 
     Precision control lighting applications can require the production and manufacturing of small addressable light emitting diode (LED) pixel systems. The smaller size of such pixel systems may require non-conventional components and manufacturing processes. 
     Semiconductor light-emitting devices including LEDs, resonant cavity light emitting diodes (RCLEDs), vertical cavity laser diodes (VCSELs), and edge emitting lasers are among the most efficient light sources available. Materials systems of interest in the manufacture of high-brightness light emitting devices capable of operation across the visible spectrum include Group III-V semiconductors, particularly binary, ternary, and quaternary alloys of gallium, aluminum, indium, and nitrogen, also referred to as III-nitride materials. III-nitride light emitting devices can be fabricated by epitaxially growing a stack of semiconductor layers of different compositions and dopant concentrations on a sapphire, silicon carbide, III-nitride, composite, or other suitable substrate by metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), or other epitaxial techniques. The stack often includes one or more n-type layers doped with, for example, Si, formed over the substrate, one or more light emitting layers in an active region formed over the n-type layer or layers, and one or more p-type layers doped with, for example, Mg, formed over the active region. Electrical contacts are formed on the n- and p-type regions. 
     III-nitride devices are often formed as inverted or flip chip devices, where both the n- and p-contacts formed on the same side of the semiconductor structure, and most of the light is extracted from the side of the semiconductor structure opposite the contacts. 
     SUMMARY 
     In accordance with an aspect of the disclosed subject matter, a first component with a first sidewall and a second component with a second sidewall may be mounted onto an expandable film such that an original distance X is the distance between the first sidewall and the second sidewall. The expandable film can be expanded such that an expanded distance Y is the distance between the first sidewall and the second sidewall and expanded distance Y is greater than original distance X. A first sidewall material may be applied within at least a part of a space between the first sidewall and the second sidewall and the expandable film may be contracted such that a contracted distance Z is the distance between the first sidewall and the second sidewall, and contracted distance Z is less than expanded distance Y. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings wherein: 
         FIG.  1 A  is a top view illustration of a micro LED array with an exploded portion; 
         FIG.  1 B  is a cross sectional illustration of a pixel matrix with trenches; 
         FIG.  1 C  is a perspective illustration of another pixel matrix with trenches; 
         FIG.  1 D  is a flowchart for mounting components, with sidewall material, onto closely configured layers; 
         FIG.  1 E  is a top view diagram showing the stages of an expandable film; 
         FIG.  1 F  is a flowchart for mounting wavelength converting layers onto closely configured layers; 
         FIG.  1 G  is a top view diagram showing the stages of another expandable film; 
         FIG.  1 H  is a cross sectional view diagram showing the stages of an expandable film; 
         FIGS.  1 I- 1 L  are diagrams of sidewall material deposited between components; 
         FIG.  1 M  is a diagram showing a thickness pattern on an expandable film; 
         FIG.  1 N  is a diagram showing light emitter structures mounted onto a light emitting device; 
         FIG.  2 A  is a top view of the electronics board with LED array attached to the substrate at the LED device attach region in one embodiment; 
         FIG.  2 B  is a diagram of one embodiment of a two channel integrated LED lighting system with electronic components mounted on two surfaces of a circuit board; 
         FIG.  2 C  is an example vehicle headlamp system; and 
         FIG.  3    shows an example illumination system. 
     
    
    
     DETAILED DESCRIPTION 
     Examples of different light illumination systems and/or light emitting diode (“LED”) implementations will be described more fully hereinafter with reference to the accompanying drawings. These examples are not mutually exclusive, and features found in one example may be combined with features found in one or more other examples to achieve additional implementations. Accordingly, it will be understood that the examples shown in the accompanying drawings are provided for illustrative purposes only and they are not intended to limit the disclosure in any way. Like numbers refer to like elements throughout. 
     It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms may be used to distinguish one element from another. For example, a first element may be termed a second element and a second element may be termed a first element without departing from the scope of the present invention. As used herein, the term “and/or” may include any and all combinations of one or more of the associated listed items. 
     It will be understood that when an element such as a layer, region, or substrate is referred to as being “on” or extending “onto” another element, it may be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or extending “directly onto” another element, there may be no intervening elements present. It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it may be directly connected or coupled to the other element and/or connected or coupled to the other element via one or more 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 between the element and the other element. It will be understood that these terms are intended to encompass different orientations of the element in addition to any orientation depicted in the figures. 
     Relative terms such as “below,” “above,” “upper,”, “lower,” “horizontal” or “vertical” may be used herein to describe a 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 are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. 
     Semiconductor light emitting devices (LEDs) or optical power emitting devices, such as devices that emit ultraviolet (UV) or infrared (IR) optical power, are among the most efficient light sources currently available. These devices (hereinafter “LEDs”), may include light emitting diodes, resonant cavity light emitting diodes, vertical cavity laser diodes, edge emitting lasers, or the like. Due to their compact size and lower power requirements, for example, LEDs may be attractive candidates for many different applications. For example, they may be used as light sources (e.g., flash lights and camera flashes) for hand-held battery-powered devices, such as cameras and cell phones. They may also be used, for example, for automotive lighting, heads up display (HUD) lighting, horticultural lighting, street lighting, torch for video, general illumination (e.g., home, shop, office and studio lighting, theater/stage lighting and architectural lighting), augmented reality (AR) lighting, virtual reality (VR) lighting, as back lights for displays, and IR spectroscopy. A single LED may provide light that is less bright than an incandescent light source, and, therefore, multi-junction devices or arrays of LEDs (such as monolithic LED arrays, micro LED arrays, etc.) may be used for applications where more brightness is desired or required. 
     According to embodiments of the disclosed subject matter, LED arrays (e.g., micro LED arrays) may include an array of pixels as shown in  FIGS.  1 A,  1 B , and/or  1 C. LED arrays may be used for any applications such as those requiring precision control of LED array segments. Pixels in an LED array may be individually addressable, may be addressable in groups/subsets, or may not be addressable. In  FIG.  1 A , a top view of a LED array  110  with pixels  111  is shown. An exploded view of a 3×3 portion of the LED array  110  is also shown in  FIG.  1 A . As shown in the 3×3 portion exploded view, LED array  110  may include pixels  111  with a width w 1  of approximately 100 μm or less (e.g., 40 μm). The lanes  113  between the pixels may be separated by a width, w 2 , of approximately 20 μm or less (e.g., 5 μm). The lanes  113  may provide an air gap between pixels or may contain other material, as shown in  FIGS.  1 B and  1 C  and further disclosed herein. The distance d 1  from the center of one pixel  111  to the center of an adjacent pixel  111  may be approximately 120 μm or less (e.g., 45 μm). It will be understood that the widths and distances provided herein are examples only, and that actual widths and/or dimensions may vary. 
     It will be understood that although rectangular pixels arranged in a symmetric matrix are shown in  FIGS.  1 A , B and C, pixels of any shape and arrangement may be applied to the embodiments disclosed herein. For example, LED array  110  of  FIG.  1 A  may include, over 10,000 pixels in any applicable arrangement such as a 100×100 matrix, a 200×50 matrix, a symmetric matrix, a non-symmetric matrix, or the like. It will also be understood that multiple sets of pixels, matrixes, and/or boards may be arranged in any applicable format to implement the embodiments disclosed herein. 
       FIG.  1 B  shows a cross section view of an example LED array  1000 . As shown, the pixels  1010 ,  1020 , and  1030  correspond to three different pixels within an LED array such that a separation sections  1041  and/or n-type contacts  1040  separate the pixels from each other. According to an embodiment, the space between pixels may be occupied by an air gap. As shown, pixel  1010  includes an epitaxial layer  1011  which may be grown on any applicable substrate such as, for example, a sapphire substrate, which may be removed from the epitaxial layer  1011 . A surface of the growth layer distal from contact  1015  may be substantially planar or may be patterned. A p-type region  1012  may be located in proximity to a p-contact  1017 . An active region  1021  may be disposed adjacent to the n-type region and a p-type region  1012 . Alternatively, the active region  1021  may be between a semiconductor layer or n-type region and p-type region  1012  and may receive a current such that the active region  1021  emits light beams. The p-contact  1017  may be in contact with SiO2 layers  1013  and  1014  as well as metal layer  1016  (e.g., plated copper). The n type contacts  1040  may include an applicable metal such as Cu. The metal layer  1016  may be in contact with a contact  1015  which may be reflective. 
     Notably, as shown in  FIG.  1 B , the n-type contact  1040  may be deposited into trenches  1130  created between pixels  1010 ,  1020 , and  1030  and may extend beyond the epitaxial layer. Separation sections  1041  may separate all (as shown) or part of a converter material  1050 . It will be understood that a LED array may be implemented without such separation sections  1041  or the separation sections  1041  may correspond to an air gap. The separation sections  1041  may be an extension of the n-type contacts  1040 , such that, separation sections  1041  are formed from the same material as the n-type contacts  1040  (e.g., copper). Alternatively, the separation sections  1041  may be formed from a material different than the n-type contacts  1040 . According to an embodiment, separation sections  1041  may include reflective material. The material in separation sections  1041  and/or the n-type contact  1040  may be deposited in any applicable manner such as, for example, but applying a mesh structure which includes or allows the deposition of the n-type contact  1040  and/or separation sections  1041 . Converter material  1050  may have features/properties similar to wavelength converting layer  205  of  FIG.  2 A . As noted herein, one or more additional layers may coat the separation sections  1041 . Such a layer may be a reflective layer, a scattering layer, an absorptive layer, or any other applicable layer. One or more passivation layers  1019  may fully or partially separate the n-contact  1040  from the epitaxial layer  1011 . 
     The epitaxial layer  1011  may be formed from any applicable material to emit photons when excited including sapphire, SiC, GaN, Silicone and may more specifically be formed from a III-V semiconductors including, but not limited to, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, II-VI semiconductors including, but not limited to, ZnS, ZnSe, CdSe, CdTe, group IV semiconductors including, but not limited to Ge, Si, SiC, and mixtures or alloys thereof. These example semiconductors may have indices of refraction ranging from about 2.4 to about 4.1 at the typical emission wavelengths of LEDs in which they are present. For example, III-Nitride semiconductors, such as GaN, may have refractive indices of about 2.4 at 500 nm, and III-Phosphide semiconductors, such as InGaP, may have refractive indices of about 3.7 at 600 nm. Contacts coupled to the LED device  200  may be formed from a solder, such as AuSn, AuGa, AuSi or SAC solders. 
     The n-type region may be grown on a growth substrate and may include one or more layers of semiconductor material that include different compositions and dopant concentrations including, for example, preparation layers, such as buffer or nucleation layers, and/or layers designed to facilitate removal of the growth substrate. These layers may be n-type or not intentionally doped, or may even be p-type device layers. The layers may be designed for particular optical, material, or electrical properties desirable for the light emitting region to efficiently emit light. Similarly, the p-type region  1012  may include multiple layers of different composition, thickness, and dopant concentrations, including layers that are not intentionally doped, or n-type layers. An electrical current may be caused to flow through the p-n junction (e.g., via contacts) and the pixels may generate light of a first wavelength determined at least in part by the bandgap energy of the materials. A pixel may directly emit light (e.g., regular or direct emission LED) or may emit light into a wavelength converting layer  1050  (e.g., phosphor converted LED, “PCLED”, etc.) that acts to further modify wavelength of the emitted light to output a light of a second wavelength. 
     Although  FIG.  1 B  shows an example LED array  1000  with pixels  1010 ,  1020 , and  1030  in an example arrangement, it will be understood that pixels in an LED array may be provided in any one of a number of arrangements. For example, the pixels may be in a flip chip structure, a vertical injection thin film (VTF) structure, a multi-junction structure, a thin film flip chip (TFFC), lateral devices, etc. For example, a lateral LED pixel may be similar to a flip chip LED pixel but may not be flipped upside down for direct connection of the electrodes to a substrate or package. A TFFC may also be similar to a flip chip LED pixel but may have the growth substrate removed (leaving the thin film semiconductor layers un-supported). In contrast, the growth substrate or other substrate may be included as part of a flip chip LED. 
     The wavelength converting layer  1050  may be in the path of light emitted by active region  1021 , such that the light emitted by active region  1021  may traverse through one or more intermediate layers (e.g., a photonic layer). According to embodiments, wavelength converting layer  1050  or may not be present in LED array  1000 . The wavelength converting layer  1050  may include any luminescent material, such as, for example, phosphor particles in a transparent or translucent binder or matrix, or a ceramic phosphor element, which absorbs light of one wavelength and emits light of a different wavelength. The thickness of a wavelength converting layer  1050  may be determined based on the material used or application/wavelength for which the LED array  1000  or individual pixels  1010 ,  1020 , and  1030  is/are arranged. For example, a wavelength converting layer  1050  may be approximately 20 μm, 50 μm or 200 μm. The wavelength converting layer  1050  may be provided on each individual pixel, as shown, or may be placed over an entire LED array  1000 . 
     Primary optic  1022  may be on or over one or more pixels  1010 ,  1020 , and/or  1030  and may allow light to pass from the active region  101  and/or the wavelength converting layer  1050  through the primary optic. Light via the primary optic may generally be emitted based on a Lambertian distribution pattern such that the luminous intensity of the light emitted via the primary optic  1022 , when observed from an ideal diffuse radiator, is directly proportional to the cosine of the angle between the direction of the incident light and the surface normal. It will be understood that one or more properties of the primary optic  1022  may be modified to produce a light distribution pattern that is different than the Lambertian distribution pattern. 
     Secondary optics which include one or both of the lens  1065  and waveguide  1062  may be provided with pixels  1010 ,  1020 , and/or  1030 . It will be understood that although secondary optics are discussed in accordance with the example shown in  FIG.  1 B  with multiple pixels, secondary optics may be provided for single pixels. Secondary optics may be used to spread the incoming light (diverging optics), or to gather incoming light into a collimated beam (collimating optics). The waveguide  1062  may be coated with a dielectric material, a metallization layer, or the like and may be provided to reflect or redirect incident light. In alternative embodiments, a lighting system may not include one or more of the following: the wavelength converting layer  1050 , the primary optics  1022 , the waveguide  1062  and the lens  1065 . 
     Lens  1065  may be formed form any applicable transparent material such as, but not limited to SiC, aluminum oxide, diamond, or the like or a combination thereof. Lens  1065  may be used to modify the a beam of light to be input into the lens  1065  such that an output beam from the lens  1065  will efficiently meet a desired photometric specification. Additionally, lens  1065  may serve one or more aesthetic purpose, such as by determining a lit and/or unlit appearance of the multiple LED devices  200 B. 
       FIG.  1 C  shows a cross section of a three dimensional view of a LED array  1100 . As shown, pixels in the LED array  1100  may be separated by trenches which are filled to form n-contacts  1140 . The pixels may be grown on a substrate  1114  and may include a p-contact  1113 , a p-GaN semiconductor layer  1112 , an active region  1111 , and an n-Gan semiconductor layer  1110 . It will be understood that this structure is provided as an example only and one or more semiconductor or other applicable layers may be added, removed, or partially added or removed to implement the disclosure provided herein. A converter material  1117  may be deposited on the semiconductor layer  1110  (or other applicable layer). 
     Passivation layers  1115  may be formed within the trenches  1130  and n-contacts  1140  (e.g., copper contacts) may be deposited within the trenches  1130 , as shown. The passivation layers  1115  may separate at least a portion of the n-contacts  1140  from one or more layers of the semiconductor. According to an implementation, the n-contacts  1140 , or other applicable material, within the trenches may extend into the converter material  1117  such that the n-contacts  1140 , or other applicable material, provide complete or partial optical isolation between the pixels. 
     According to embodiments of the disclosed subject matter, an expandable film may be configured to expand the space between components (e.g., wavelength converting layers, dies, etc.) that are mounted onto the expandable tape, resulting in expanded lanes between the converter components. The expanded lanes may enable application of one or more sidewall material such as spacer material or optical isolation materials, or one or more additional components (e.g., one or more wavelength converting layers with the same or different properties as the wavelength converting layers already on the expandable film). A spacer material may be any applicable material configured to separate two or more components and may enable the separation to allow alignment with light emitting devices, as disclosed herein. Optical isolation material may be distributed Bragg reflector (DBR) layers, reflective material, absorptive material, or the like. The sidewall materials may be applied to one or more sidewalls of the components or may be deposited within the lanes such that they at least partially take the form of the expanded lanes. Alternatively or in addition, one or more components may be deposited within the lanes. The expandable film may then be contracted, resulting in the expanded lanes contracting to a smaller width. The components along with all or a part of the sidewall materials may then be mounted onto a light emitting device such as, but not limited to gallium nitride (GaN) mesas, LEDs, light active material, conductors, or the like. 
     It will be understood that although wavelength converting layers are specifically used in some examples of this disclosure, any applicable components (e.g., wavelength converting layer(s), semiconductor layer(s), die(s), substrate(s), etc.) may be applied to a film that can expand, in accordance with this disclosure. 
     Wavelength converting layers may contain, but are not limited to, one or more applicable luminescent or optically scattering material such as phosphor particles or other particles as previously disclosed herein. 
       FIG.  1 D  shows a flow chart  1200  with steps to apply sidewall material to sidewalls and/or within lanes of small addressable LED pixel systems. 
     According to an embodiment of the disclosed subject matter, at step  1201  of  FIG.  1 D , as also shown via a top view in  FIG.  1 E , a plurality of components  1340  may be mounted on an un-expanded expandable film  1310 . For clarity,  FIG.  1 E  shows the same expandable film in three different states.  1310  shows the expandable film in an un-expanded state,  1320  shows the expandable film in an expanded state and  1330  shows the expandable film after it has been expanded and contracted. As discussed below, the contracted expandable film  1330  may contract to the same size as the expandable film  1310  prior to being expanded or may contract to a different size. 
     The plurality of components  1340  may be mounted using any applicable technique such as bonding via adhesive, micro-connectors, or one or more physical connector. As an example, an adhesive may be applied using a spin-on process. The expandable film may be a blue tape, a white tape, a UV tape, or any other suitable material that allows mounting to a flexible/expandable film. The distance w 5  between the lanes  1311  created between components  1340  may be small, such as approximately 50 μm. In an embodiment, the distance of lanes  1311  may be 20 μm. 
     At step  1202  of  FIG.  1 D , as also shown in  FIG.  1 E  the expandable film  1310  may be expanded as shown by expandable film  1320 . The expansion may be an isotropic expansion such that the un-expanded expandable film  1310  is expanded substantially linearly to the expanded state of the expandable film  1320 . As a non limiting example, the expansion may be isotropic such that a 20 μm expansion in the left direction may result in the center of the film to shift 10 μm left and the expandable film overall to expand linearly by 20 μm. According to an embodiment of the disclosed subject matter, the expandable film may expand in a non-linear manner which may be pre-determined or detectible based on the resulting expanded film  1320 . As an example, a non-linear expansion may be one that results in a greater amount of expansion towards the edges of the expandable film and a lower amount of expansion towards the center. As an alternate example, a non-linear expansion may be one that results in a greater amount of expansion where a mechanism that causes the expansion is located. A mechanism that causes the expansion may be, for example, via a heat source, a clamp, a pulling mechanism, or the like. As an example, the expandable film may be expanded via a thermochemical expansion which allows the film to expand based on gradually increasing the temperature with high control fidelity. The film may contract when the temperature is lowered. 
     As shown in  FIG.  1 E , the distance between the components  1340  that creates the lanes  1311  may increase from the original distance w 5  on the un-expanded expandable film  1310  to a larger distance w 6  for lanes  1321 . The distance w 6  may be sufficient to apply sidewall material to the sidewalls of the components  1340 , as discussed herein. 
     At step  1203  of  FIG.  1 D , as also shown in  FIG.  1 E , sidewall material  1350  may be applied within at least part of the expanded space between components  1340 . The sidewall material may be any applicable spacer material or optical isolation material such as a distributed Bragg reflector (DBR) layer(s), reflective material, absorptive material, or the like. As specific examples, the sidewall material may include stainless steel or aluminum. DBR layers may include, but are not limited to, layers of SiO 2  and TiO 2 ; SiO 2  and ZrO 2 ; SiC and MgO; SiC and Silica; GaAs and AlAs; ITO; or a-Si and a-Si. The amount of space w 6  between the wavelength converting layers  340  may allow the application of the sidewall material  1350 . 
     At step  1204  of  FIG.  1 D , as also shown in  FIG.  1 E , the expandable film may be contracted as shown by expandable film  1330 . The contraction may result in an isotropic contraction such that the contracted film  1330  is contracted substantially linearly to the state of the contracted film  1330 . As a non limiting example, the contraction may be isotropic such that a 20 μm contraction towards the center may result in both the left side and the right side of the film to contract by 10 μm towards the center and the expandable film overall to contract linearly. According to an embodiment of the disclosed subject matter, the expandable film may contract in a non-linear manner which may be pre-determined or detectible based on the resulting contracted film. As a non limiting example, a non-linear contraction may be one that results in a greater amount of contraction by the top edges of the expandable film and a lower amount of expand by the bottom edge of the expandable film. As an alternate example, a non-linear contraction may be one that results in a lower amount of contraction where a mechanism that caused the expansion is located. 
     It should be noted that the amount of space w 5  or w 7  between the components  1340  that creates the lanes  1311  on the un-expanded expandable film  1310  or the lanes  1331  in contracted expandable film  1330  may not allow an application of sidewall material, as disclosed herein. As a specific non limiting example in reference to  FIG.  1 E , w 5  may be 50 μm wide, w 6  may be 100 μm wide, and w 7  may be 20 μm wide. In this example, it should be noted that w 7  is less than w 5  (20 μm wide vs. 50 μm wide) as, in this example, w 7  is calculated as the width between the sidewall materials  1350  applied to the sidewalls of adjacent wavelength converting layers  1340 . 
     An expandable film may be expanded to deposit one or more wavelength converting layers between wavelength converting layers placed on an unexpanded expandable film. The one or more wavelength converting layers to be placed may have the same properties (e.g., peak wavelength emission, phosphor particle type, dimension, etc.) as the wavelength converting layers placed on the unexpanded expandable film. Alternatively or in addition, the one or more wavelength converting layers to be placed may allow for color variation such that the one or more wavelength converting layers may have properties different than the wavelength converting layers placed on the unexpanded expandable film.  FIG.  1 F  shows a flow chart  1300  with steps to apply one or more wavelength converting layers within lanes between originally placed wavelength converting layers, the lanes created by expanding the expandable film, as disclosed herein. 
     According to an embodiment of the disclosed subject matter, at step  1301  of  FIG.  1 F , as also shown via a top view in  FIG.  1 G , a plurality of wavelength converting layers  1341  may be mounted on an un-expanded expandable film  1310 . For clarity,  FIG.  1 F  shows the same expandable film in three different states.  1310  shows the expandable film in an un-expanded state,  1325  shows the expandable film in an expanded state and  1335  shows the expandable film after it has been expanded and contracted. As discussed below, the contracted expandable film  1335  may contract to the same size as the expandable film  1310  prior to being expanded or may contract to a different size. 
     The plurality of wavelength converting layers  1341  may be mounted using any applicable technique such as bonding via adhesive, micro-connectors, or one or more physical connector. As an example, an adhesive may be applied using a spin-on process. The expandable film may be a blue tape, a white tape, a UV tape, or any other suitable material that allows mounting to a flexible/expandable film. The distance w 5  between the lanes  1311  created between wavelength converting layers  1341  may be small, such as approximately 50 μm. In an embodiment, the distance of lanes  1311  may be 20 μm. 
     At step  1302  of  FIG.  1 F , as also shown in  FIG.  1 G  the expandable film  1310  may be expanded as shown by expandable film  1325 . The expansion may be an isotropic expansion such that the un-expanded expandable film  1310  is expanded substantially linearly to the expanded state of the expandable film  1320 . As a non limiting example, the expansion may be isotropic such that a 100 μm expansion in the left direction may result in the center of the film to shift 50 μm left and the expandable film overall to expand linearly by 100 μm. According to an embodiment of the disclosed subject matter, the expandable film may expand in a non-linear manner which may be pre-determined or detectible based on the resulting expanded film  1325 . As an example, a non-linear expansion may be one that results in a greater amount of expansion towards the edges of the expandable film and a lower amount of expansion towards the center. As an alternate example, a non-linear expansion may be one that results in a greater amount of expansion where a mechanism that causes the expansion is located. A mechanism that causes the expansion may be, for example, via a heat source, a clamp, a pulling mechanism, or the like. As an example, the expandable film may be expanded via a thermochemical expansion which allows the film to expand based on gradually increasing the temperature with high control fidelity. The film may contract when the temperature is lowered. 
     As shown in  FIG.  1 G , the distance between the components  1340  that creates the lanes  1311  may increase from the original distance w 5  on the un-expanded expandable film  1310  to a larger distance w 8  for lanes  1326 . The distance w 8  may be sufficient to apply one or more additional wavelength converting layers, as discussed herein. 
     At step  1303  of  FIG.  1 F , as also shown in  FIG.  1 G , one or more additional wavelength converting layers  1342  and  1343  may be applied within at least part of the expanded space between wavelength converting layers  1341 . The additional wavelength converting layers may be the same as or similar to the wavelength converting layers  1341  or may be different than the wavelength converting layers  1341 . According to an example, wavelength converting layers  1341  may be configured to emit a red peak wavelength, wavelength converting layers  1342  may be configured to emit a green peak wavelength, and wavelength converting layers  1343  may be configured to emit a blue peak wavelength. 
     According to an embodiment, the expandable film  1310  may be expanded in a first direction, such as horizontally in  FIG.  1 G , such that a first type of wavelength converting layers  1342  is deposited in the space created by the horizontal expansion. The expandable film may be expanded in a second direction, such as vertically in  FIG.  1 G , such that a second type of wavelength converting layer  1343  is deposited in the space created by the vertical expansion. The expansion in the first direction and in the second direction may occur at the same time or may occur in a sequence. 
     At step  1304  of  FIG.  1 F , as also shown in  FIG.  1 G , the expandable film may be contracted, as shown by expandable film  1335 . The contraction may result in an isotropic contraction such that the contracted film  1335  is contracted substantially linearly to the state of the contracted film  1335 . As a non limiting example, the contraction may be isotropic such that a 20 μm contraction towards the center may result in both the left side and the right side of the film to contract by 10 μm towards the center and the expandable film overall to contract linearly. According to an embodiment of the disclosed subject matter, the expandable film may contract in a non-linear manner which may be pre-determined or detectible based on the resulting contracted film. As a non limiting example, a non-linear contraction may be one that results in a greater amount of contraction by the top edges of the expandable film and a lower amount of expand by the bottom edge of the expandable film. As an alternate example, a non-linear contraction may be one that results in a lower amount of contraction where a mechanism that caused the expansion is located. 
     It should be noted that the amount of space w 5  or w 9  between the wavelength converting layers  1341  that creates the lanes  1311  on the un-expanded expandable film  1310  or the lanes  1333  in contracted expandable film  1335  may not allow an application of wavelength converting layers, as disclosed herein. As a specific non limiting example in reference to  FIG.  1 G , w 5  may be 50 μm wide, w 8  may be 140 μm wide, and w 9  may be 10 μm wide. In this example, it should be noted that w 9  is less than w 5  (10 μm wide vs. 50 μm wide). 
       FIG.  1 H  shows a cross-sectional view of the expanded expandable film  1320  and the collapsed expandable film  1330 . As shown in  FIG.  1 H , the expanded expandable film  1320  allows for a wide lane with a width of w 6 . When collapsed, expandable film  1330  contracts such that the lane width between the wavelength converting layers  1340  with a sidewall material  1350  is reduced to w 7  which is less than the wider width w 6 . 
     According to an embodiment disclosed herein, as show in  FIG.  1 I , mounting components  1511  onto an expandable film  1510 , expanding the expandable film, applying sidewall materials  1512  to the sidewalls of the components  1511 , and collapsing the expandable film  1510  may result in a narrow lane  1520  between two adjacent sidewall materials  1512 . As a non-limiting example, such a narrow lane  1520  may be present if the sidewall materials  1512  are DBR layers applied to the sidewalls of the adjacent components  1511 . The narrow lane may have a width such that it allows the spacing between the components  1511  to align components  1511  for mounting onto a light emitting device, as disclosed herein in step  1204  of  FIG.  1 D . Specifically, the width of the narrow lane may enable components  1511  to be positioned directly opposite their respective light emitting device so that a plurality of wavelength converting layers on an expandable film may be mounted onto a plurality of light emitting devices substantially simultaneously. A visual representation of this alignment is shown in  FIG.  1 N . 
     According to an embodiment disclosed herein, as show in  FIG.  1 J , mounting components  1511  onto an expandable film, expanding the expandable film, applying sidewall materials  1513  within the lanes created between adjacent components  1511 , and collapsing the expandable film  1510  may result in a filled lane between two adjacent components  1511 . As a non-limiting example, such a filled lane may be present if the sidewall material  1513  is an absorptive material or a reflective material. The absorptive or reflective material may be poured into the lanes while the expandable film is expanded, such that it assumes the form of the lanes either while the expandable film is expanded or when the expandable film is collapsed. The filled lane may have a width such that it allows the filled spacing between the components  1511  to align components  1511  for mounting onto a light emitting device. Specifically, the width of the filled lane may enable respective components  1511  to be positioned directly opposite their paired light emitting device so that a plurality of wavelength converting layers on an expandable film may be mounted onto a plurality of light emitting devices substantially simultaneously. A visual representation of this alignment is shown in  FIG.  1 N . 
     According to an embodiment disclosed herein, as show in  FIG.  1 K , mounting components  1511  onto an expandable film, expanding the expandable film, applying sidewall materials  1512  and  513  within the lanes created between adjacent wavelength converting layers  511 , and collapsing the expandable film  510  may result in a filled lane between two adjacent sidewall materials  512 . According to this embodiment, a first sidewall material  1512  may be applied to the sidewalls of adjacent wavelength converting layers and a second sidewall material  1513  may be poured into the lanes between adjacent sidewall materials  1512 . Both the sidewall materials  1512  and  1513  may be applied while the expandable film is expanded. As a specific non limiting example, the sidewall material  1512  may be one or more DBR layers and may be applied directly to the sidewalls of adjacent components  1511 . The sidewall material  1513  may be absorptive material or a reflective material. The absorptive or reflective material may be poured into the lanes while the expandable film is expanded, such that it assumes the form of the lanes either while the expandable film is expanded or when the expandable film is collapsed. The combined width of the sidewall materials  1512  and  1513  may allow the spacing between the components  1511  to align components  1511  for mounting onto a light emitting device. Specifically, the width of the sidewall materials  1512  and  1513  may enable respective components  1511  to be positioned directly opposite their paired light emitting device so that a plurality of wavelength converting layers on an expandable film may be mounted onto a plurality of light emitting devices substantially simultaneously. A visual representation of this alignment is shown in  FIG.  1 N . 
     According to an embodiment disclosed herein, as show in  FIG.  1 L , mounting components  1511  (e.g., wavelength converting layers) onto an expandable film, expanding the expandable film, applying sidewall materials  1512  to the sidewalls of the components  1511 , and collapsing the expandable film  1510  may result in no space between adjacent sidewall materials  1512 . As a non-limiting example, no space may be present if the sidewall materials  512  are DBR layers applied to the sidewalls of the adjacent components  1511 . The adjacent sidewall materials  1512  may have a width such that the width allows the spacing between the components  1511  to align components  1511  for mounting onto a light emitting device. Specifically, the width of adjacent sidewall materials  1512  may enable respective components  1511  to be positioned directly opposite their paired light emitting device so that a plurality of wavelength converting layers on an expandable film may be mounted onto a plurality of light emitting devices substantially simultaneously. A visual representation of this alignment is shown in  FIG.  1 N . 
     According to an embodiment of the disclosed subject matter, an expandable film may expand or contract following an affine deformation. To reduce stress buildup on the expandable film, especially where wavelength converting layers are located, an expandable film thickness pattern may be implemented, as shown in  FIG.  1 M . An expandable film  1620  may contain varying levels of thickness such as thicker sections  1621  and thinner sections  1622 . Wavelength converting layers  1610  may be mounted onto the thicker sections  1621  of the expandable film, as shown in the top block  1601 , such that, when the expandable film is expanded or contracted, all or part of the added stress due to the mounted wavelength converting layers  1610  is compensated for and normalized, as a result of the added thickness of the thicker sections  1621 . 
     The expanded expandable film is illustrated on the bottom block  1602  of  FIG.  1 M . As shown, the thicker sections  1621  may substantially maintain their width, w 11 , as the expandable film changes from an un-expanded state to an expanded state. The thinner sections  1622  may experience a majority of the expanding and contracting, as shown by the difference in widths w 9  and w 10 . As shown, w12 is smaller than w 12 . Here, w 11  corresponds to the width of the thinner sections while the expandable film is un-expanded and w 12  corresponds to the width of the thinner sections when the expandable film is expanded. According to an embodiment, the thicker sections of an expandable film are at least twice as thick as the thinner sections of an expandable film. 
     According to an embodiment and as also shown in  FIG.  1 M , the surface area of the side of the wavelength converting layers  1610  that is in contact with the expandable film may be larger than the surface area of the thicker sections  1621  of the expandable film onto which the wavelength converting layers  1610  are mounted. 
     It will be understood that although square and/or rectangular patterns are described to represent the thicker and thinner portions of an expandable film, any applicable pattern that allows for a thicker section and a thinner section of an expandable film may be implemented. Such patterns can include, but are not limited to, circular features, elliptical features, crosses, non-symmetric features and the like. 
     According to an embodiment, a collapsible film is disclosed such that one or more components are placed on the collapsible film and, once placed, the film is collapsed to reduce the space between the components. According to this embodiment, sidewall material may be added before the collapsible film is collapsed such that once the collapsible film is collapsed, there may not be enough space between components to add sidewall material. 
     As shown in  FIG.  1 N , wavelength converting layers  1720  may be attached to light emitting devices  1770  of an LED array  1700 , to create pixels  1775 . In  FIG.  1 N , light emitting devices  1770  may include GaN layer  1750 , active region  1790 , one or more contacts  1780 , pattern sapphire substrate (PSS)  1760 , and wavelength converting layers  1720 . The wavelength converting layers  1720  are shown on a contracted expandable film  1710 , in accordance with the subject matter disclosed herein. The contracted expandable film  1710  may be contracted such that the distance between the wavelength converting layers  1720  enables the wavelength converting layers  1720  to align with the light emitting devices  1770  and to be attached to the light emitting devices  1770 . More specifically, the spacing created between the wavelength converting layers  1720  during the expansion of the expandable film  1710 , the application of a side layer material or additional wavelength converting layers  1720 , and the contraction of the expandable film  1710  may allow the wavelength converting layers  1720  to be mounted onto the light emitting devices  1770 . 
     As shown in  FIG.  1 N , sidewall materials  1730  may be applied to the wavelength converting layers  1720 . The wavelength converting layers  1720  may be mounted over GaN layers  1750  and pattern sapphire substrate (PSS) patterns  1760  may be located between the GaN layers  1750  and the wavelength converting layers. Active regions  1790  may be configured to emit light at least partially towards the wavelength converting layers  1720  and the light emitting devices  1770  may include contacts  1780 . Optical isolator material  1740  may be applied to the sidewalls of the GaN layer  1750 . The expandable film  1710  may be removed from the wavelength converting layers  1720 , for example, after the wavelength converting layers  1720  have been attached to the light emitting devices  1770 . 
     As an example, the pixels  1775  of  FIG.  1 N  may correspond to the pixels  111  of  FIG.  1 A-C . Specifically, as shown in  FIG.  1 A , the pixels  111  may correspond to the pixels  1775  of  FIG.  1 N  after the wavelength converting layers  1720  are mounted onto the light emitting devices  1770 . When the pixels  111  or  1775  are activated, the respective active regions  1790  of the emitters may generate a light. The light may pass through the wavelength converting layers  1720  and may substantially be emitted from the surface of the pixels  1775  (after the expandable film  1710  has been removed) and light that reaches the sidewalls of the wavelength converting layers  1720  may not escape from the sidewalls due to the sidewall materials  1730  and may be reflected when it intersects the sidewalls due to the sidewall materials  1730 . 
       FIG.  2 A  is a top view of an electronics board with an LED array  410  attached to a substrate at the LED device attach region  318  in one embodiment. The electronics board together with the LED array  410  represents an LED system  400 A. Additionally, the power module  312  receives a voltage input at Vin  497  and control signals from the connectivity and control module  316  over traces  418 B, and provides drive signals to the LED array  410  over traces  418 A. The LED array  410  is turned on and off via the drive signals from the power module  312 . In the embodiment shown in  FIG.  2 A , the connectivity and control module  316  receives sensor signals from the sensor module  314  over trace  418 C. The pixels  1775  of  FIG.  1 N  may correspond to the in the pixels in the LED array  410  of  FIG.  2 A  and may be manufactured in accordance with the techniques disclosed in  FIGS.  1 D- 1 M . 
       FIG.  2 B  illustrates one embodiment of a two channel integrated LED lighting system with electronic components mounted on two surfaces of a circuit board  499 . As shown in  FIG.  2 B , an LED lighting system  400 B includes a first surface  445 A having inputs to receive dimmer signals and AC power signals and an AC/DC converter circuit  412  mounted on it. The LED system  400 B includes a second surface  445 B with the dimmer interface circuit  415 , DC-DC converter circuits  440 A and  440 B, a connectivity and control module  416  (a wireless module in this example) having a microcontroller  472 , and an LED array  410  mounted on it. The LED array  410  is driven by two independent channels  411 A and  411 B. In alternative embodiments, a single channel may be used to provide the drive signals to an LED array, or any number of multiple channels may be used to provide the drive signals to an LED array. 
     The LED array  410  may include two groups of LED devices. In an example embodiment, the LED devices of group A are electrically coupled to a first channel  411 A and the LED devices of group B are electrically coupled to a second channel  411 B. Each of the two DC-DC converters  440 A and  440 B may provide a respective drive current via single channels  411 A and  411 B, respectively, for driving a respective group of LEDs A and B in the LED array  410 . The LEDs in one of the groups of LEDs may be configured to emit light having a different color point than the LEDs in the second group of LEDs. Control of the composite color point of light emitted by the LED array  410  may be tuned within a range by controlling the current and/or duty cycle applied by the individual DC/DC converter circuits  440 A and  440 B via a single channel  411 A and  411 B, respectively. Although the embodiment shown in  FIG.  2 B  does not include a sensor module (as described in  FIG.  2 A ), an alternative embodiment may include a sensor module. 
     The illustrated LED lighting system  400 B is an integrated system in which the LED array  410  and the circuitry for operating the LED array  410  are provided on a single electronics board. Connections between modules on the same surface of the circuit board  499  may be electrically coupled for exchanging, for example, voltages, currents, and control signals between modules, by surface or sub-surface interconnections, such as traces  431 ,  432 ,  433 ,  434  and  435  or metallizations (not shown). Connections between modules on opposite surfaces of the circuit board  499  may be electrically coupled by through board interconnections, such as vias and metallizations (not shown). 
     According to embodiments, LED systems may be provided where an LED array is on a separate electronics board from the driver and control circuitry. According to other embodiments, a LED system may have the LED array together with some of the electronics on an electronics board separate from the driver circuit. For example, an LED system may include a power conversion module and an LED module located on a separate electronics board than the LED arrays. 
     According to embodiments, an LED system may include a multi-channel LED driver circuit. For example, an LED module may include embedded LED calibration and setting data and, for example, three groups of LEDs. One of ordinary skill in the art will recognize that any number of groups of LEDs may be used consistent with one or more applications. Individual LEDs within each group may be arranged in series or in parallel and the light having different color points may be provided. For example, warm white light may be provided by a first group of LEDs, a cool white light may be provided by a second group of LEDs, and a neutral white light may be provided by a third group. 
       FIG.  2 C  shows an example vehicle headlamp system  300  including a vehicle power  302  including a data bus  304 . A sensor module  307  may be connected to the data bus  304  to provide data related to environment conditions (e.g. ambient light conditions, temperature, time, rain, fog, etc.), vehicle condition (parked, in-motion, speed, direction), presence/position of other vehicles, pedestrians, objects, or the like. The sensor module  307  may be similar to or the same as the sensor module  314  of  FIG.  2 A . AC/DC Converter  305  may be connected to the vehicle power  302 . The pixels  1775  of  FIG.  1 N  may correspond to the in the pixels in the active head lamp  330  of  FIG.  2 C  and may be manufactured in accordance with the techniques disclosed in  FIGS.  1 D- 1 M . 
     The power module  312  (AC/DC converter) of  FIG.  2 C  may be the same as or similar to the AC/DC converter  412  of  FIG.  2 B  and may receive AC power from the vehicle power  302 . It may convert the AC power to DC power as described in  FIG.  2 B  for AC-DC converter  412 . The vehicle head lamp system  300  may include an active head lamp  330  which receives one or more inputs provided by or based on the AC/DC converter  305 , connectivity and control module  306 , and/or sensor module  307 . As an example, the sensor module  307  may detect the presence of a pedestrian such that the pedestrian is not well lit, which may reduce the likelihood that a driver sees the pedestrian. Based on such sensor input, the connectivity and control module  306  may output data to the active head lamp  330  using power provided from the AC/DC converter  305  such that the output data activates a subset of LEDs in an LED array contained within active head lamp  330 . The subset of LEDs in the LED array, when activated, may emit light in the direction where the sensor module  307  sensed the presence of the pedestrian. These subset of LEDs may be deactivated or their light beam direction may otherwise be modified after the sensor module  207  provides updated data confirming that the pedestrian is no longer in a path of the vehicle that includes vehicle head lamp system. 
       FIG.  3    shows an example system  550  which includes an application platform  560 , LED systems  552  and  556 , and optics  554  and  558 . LED system  552  and  556  may include LED arrays generated in accordance with the techniques disclosed in  FIGS.  1 D-M . The LED System  552  produces light beams  561  shown between arrows  561   a  and  561   b.  The LED System  556  may produce light beams  562  between arrows  562   a  and  562   b.  In the embodiment shown in  FIG.  3   , the light emitted from LED System  552  passes through secondary optics  554 , and the light emitted from the LED System  556  passes through secondary optics  556 . In alternative embodiments, the light beams  561  and  562  do not pass through any secondary optics. The secondary optics may be or may include one or more light guides. The one or more light guides may be edge lit or may have an interior opening that defines an interior edge of the light guide. LED systems  552  and/or  556  may be inserted in the interior openings of the one or more light guides such that they inject light into the interior edge (interior opening light guide) or exterior edge (edge lit light guide) of the one or more light guides. LEDs in LED systems  552  and/or  556  may be arranged around the circumference of a base that is part of the light guide. According to an implementation, the base may be thermally conductive. According to an implementation, the base may be coupled to a heat-dissipating element that is disposed over the light guide. The heat-dissipating element may be arranged to receive heat generated by the LEDs via the thermally conductive base and dissipate the received heat. The one or more light guides may allow light emitted by LED systems  552  and  556  to be shaped in a desired manner such as, for example, with a gradient, a chamfered distribution, a narrow distribution, a wide distribution, an angular distribution, or the like. 
     In example embodiments, the system  550  may be a mobile phone of a camera flash system, indoor residential or commercial lighting, outdoor light such as street lighting, an automobile, a medical device, AR/VR devices, and robotic devices. The LED System  400 A shown in  FIG.  2 A  and vehicle head lamp system  300  shown in  FIG.  2 C  illustrate LED systems  552  and  556  in example embodiments. 
     The application platform  560  may provide power to the LED systems  552  and/or  556  via a power bus via line  565  or other applicable input, as discussed herein. Further, application platform  560  may provide input signals via line  565  for the operation of the LED system  552  and LED system  556 , which input may be based on a user input/preference, a sensed reading, a pre-programmed or autonomously determined output, or the like. One or more sensors may be internal or external to the housing of the application platform  560 . Alternatively or in addition, as shown in the LED system  400  of  FIG.  2 A , each LED System  552  and  556  may include its own sensor module, connectivity and control module, power module, and/or LED devices. 
     In embodiments, application platform  560  sensors and/or LED system  552  and/or  556  sensors may collect data such as visual data (e.g., LIDAR data, IR data, data collected via a camera, etc.), audio data, distance based data, movement data, environmental data, or the like or a combination thereof. The data may be related a physical item or entity such as an object, an individual, a vehicle, etc. For example, sensing equipment may collect object proximity data for an ADAS/AV based application, which may prioritize the detection and subsequent action based on the detection of a physical item or entity. The data may be collected based on emitting an optical signal by, for example, LED system  552  and/or  556 , such as an IR signal and collecting data based on the emitted optical signal. The data may be collected by a different component than the component that emits the optical signal for the data collection. Continuing the example, sensing equipment may be located on an automobile and may emit a beam using a vertical-cavity surface-emitting laser (VCSEL). The one or more sensors may sense a response to the emitted beam or any other applicable input. 
     In example embodiment, application platform  560  may represent an automobile and LED system  552  and LED system  556  may represent automobile headlights. In various embodiments, the system  550  may represent an automobile with steerable light beams where LEDs may be selectively activated to provide steerable light. For example, an array of LEDs may be used to define or project a shape or pattern or illuminate only selected sections of a roadway. In an example embodiment, Infrared cameras or detector pixels within LED systems  552  and/or  556  may be sensors (e.g., similar to sensors module  314  of  FIG.  2 A and  307    of  FIG.  2 C ) that identify portions of a scene (roadway, pedestrian crossing, etc.) that require illumination. 
     Having described the embodiments in detail, those skilled in the art will appreciate that, given the present description, modifications may be made to the embodiments described herein without departing from the spirit of the inventive concept. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described. Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs).