Forming multicolor phosphor converted led arrays

Abstract

A phosphor pixel array is located on top of a semiconductor LED pixel array with a heat-curable adhesive therebetween. Selected LED pixels of the array are electrically activated; the resulting heat causes the adhesive to cure, thereby attaching the corresponding phosphor pixel to the activated LED pixel and releasing the corresponding phosphor pixel from the carrier. Removal of the carrier removes the unattached phosphor pixels, leaving the phosphor pixels attached to the activated LED pixels. This process can be repeated for phosphor pixels of different colors.

Description

[0001] Priority requirements

[0002] This application claims priority to U.S. Application No. 16 / 653414, filed October 15, 2019, and European Application No. 20157722.8, filed February 17, 2020. The entire contents of each of these applications are incorporated herein by reference. Technical Field

[0003] This invention generally relates to phosphorescent light-emitting diodes (LEDs). Background Technology

[0004] Due to their superior image quality, lower power consumption, and enhanced reliability, RGB microLED displays hold promise as the next-generation display technology. Currently, several methods exist for forming large arrays of multi-color, micrometer-scale, and closely spaced pixels. One option is to assemble each pixel from individual red, green, and blue LED dies. Another option is to pattern the red and green sub-pixels onto blue pixelated dies via imprinting, photolithography, or inkjet printing. Summary of the Invention

[0005] A method of manufacturing a light-emitting device includes positioning a phosphor structure on a semiconductor LED array and selectively operating selected semiconductor LED pixels among a plurality of semiconductor LED pixels constituting the array. The phosphor structure includes a plurality of phosphor pixels and is positioned such that each phosphor pixel is aligned with a corresponding semiconductor LED pixel of the array. The phosphor structure has a layer of thermosetting adhesive; when the phosphor structure is located on the semiconductor LED array, corresponding segments of the adhesive are positioned between and in contact with the light-output surfaces of each phosphor pixel and the corresponding semiconductor LED pixel. Selected semiconductor LED pixels are electrically operated to emit light and heat the corresponding phosphor pixels to a temperature that at least partially cures the corresponding discrete segments of the adhesive. Thermosetting of the adhesive bonds each of the selected semiconductor LED pixels to the corresponding phosphor pixel.

[0006] The method may further include positioning a second phosphor structure on a semiconductor LED array and selectively manipulating selected semiconductor LED pixels among a plurality of semiconductor LED pixels in the second array. The phosphor pixels of the first phosphor structure all have a first color; the second phosphor structure includes a plurality of phosphor pixels, all having a second color different from the first color. The second phosphor structure is located on the semiconductor LED array and the phosphor pixels of the first color, wherein each phosphor pixel of the second color is aligned with a corresponding semiconductor LED pixel in the array that is not bonded to a phosphor pixel of the first color. The second phosphor structure has a layer of thermosetting adhesive; when the second phosphor structure is located on the semiconductor LED array, corresponding segments of the adhesive are located between and in contact with each phosphor pixel of the second color and its corresponding semiconductor LED pixel. Selected semiconductor LED pixels are electrically operated to emit light, and the corresponding phosphor pixels of the second color are heated to a temperature that at least partially cures the corresponding discrete segments of the adhesive. The thermal curing of the adhesive bonds each of the selected semiconductor LED pixels to the corresponding phosphor pixel of the second color.

[0007] A light-emitting device includes a semiconductor LED array having multiple semiconductor LED pixels, multiple corresponding phosphor pixels of various colors, and multiple discrete segments of thermosetting adhesive. Each phosphor pixel is located on the light-emitting surface of a corresponding semiconductor LED pixel. Between each phosphor pixel and its corresponding semiconductor LED pixel is a corresponding discrete segment of thermosetting adhesive for attaching the phosphor pixel to the corresponding semiconductor LED pixel. Each discrete segment of thermosetting adhesive is separate from other discrete segments of thermosetting adhesive between other phosphor pixels and their corresponding semiconductor LED pixels in the array.

[0008] The objectives and advantages associated with phosphor-converting light-emitting diodes (LEDs) can be made clear by referring to the example embodiments shown in the accompanying drawings and the following written description or appended claims.

[0009] This summary is provided to present a simplified description of selected concepts, which will be further described in the detailed description below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter. Attached Figure Description

[0010] Figure 1A This is a schematic side cross-sectional view of an example of a close-packed array of multicolor phosphor-converting LEDs on a single die and substrate. Figure 1BThis is a schematic top view of a portion of an example LED display, where each display pixel is a red, green, or blue phosphor-converted LED pixel. Figure 1C This is a schematic top view of a portion of an example LED display, where each display pixel includes multiple phosphor-converting LED pixels (red, green, and blue) integrated onto a single die, which is coupled to a control circuitry backplane.

[0011] Figure 2 A process flow diagram for an example of the disclosed method.

[0012] Figure 3A , 3B The diagrams 3C and 3C are schematic illustrations of a side cross-sectional view of a semiconductor LED array in which phosphor pixels of three different colors are selected by position and attached in color order according to an example method.

[0013] Figure 4A and Figure 4B These are side section views and top views, which schematically illustrate... Figure 3A The three parallel attachment processes of the general type shown in / 3B / 3C, and the use of each substrate carrying a phosphor pixel in each of the different parallel processes.

[0014] Figure 5A , 5B Similar to 5C Figure 3A , 3B And 3C, but shows phosphor pixels of different colors with different thicknesses.

[0015] The depicted embodiments are illustrative only; all features may not be shown in full detail or to the appropriate scale; for clarity, some features or structures may be exaggerated or reduced relative to others, or omitted entirely; the drawings should not be considered to scale unless explicitly indicated otherwise. For example, the relative height, depth, or width of various layers or structures of an LED array, each LED pixel, or phosphor layer or pixel may generally be exaggerated relative to the relative height, depth, or width of other layers or structures (e.g., the thickness of the underlying substrate). The illustrated embodiments are merely examples and should not be construed as limiting the scope of this disclosure or the appended claims. Detailed Implementation

[0016] The following detailed description should be read with reference to the accompanying drawings, in which the same reference numerals refer to similar elements throughout the various figures. The drawings, which are not necessarily to scale, depict selective examples and are not intended to limit the scope of this disclosure or the appended claims. The detailed description illustrates the inventive principles of this disclosure and the appended claims by way of example, not by way of limitation.

[0017] The term "GaN LED" as used herein refers to a Group III nitride LED, i.e., an LED formed in the AlInGaN material system. The following example is described with reference to such a GaN LED; however, the methods described herein can be used for Group III phosphide (AlInGaP material system) LEDs or for LEDs formed in any other suitable material system.

[0018] This invention describes a monolithic method for manufacturing a high-density patterned or multi-color phosphor-converting LED array 10 without requiring a serial pick-and-place step for each individual pixel. This avoids the significant adhesion accuracy problems associated with serial pick-and-place, which result in wide gaps between adjacent pixels. Unlike imprint-based methods, no additional patterning step is required before the adhesion process—color selectivity occurs during phosphor integration. Accuracy can be improved by using a monolithic method and one-step adhesion for each color. Additionally, yield can be increased by introducing a small number of error correction steps in the phosphor placement process.

[0019] In the method disclosed herein, the layered carrier assembly sequentially includes a substrate 30 (e.g., PET), a thermally or UV-activated release adhesive 32, a layer comprising a segmented (pixelated) phosphor array, and a partially cured or high-tack silicone adhesive 20. The phosphor pixels 18 on the carrier 30 are typically all the same color. In many display applications, the assembled array will include phosphor pixels 18 of different colors. All phosphor pixels 18 of all colors are generally or collectively referred to herein as phosphor pixels 18, while phosphor pixels of specific colors are referred to in the RGB display color scheme as phosphor pixels 18R (red), 18G (green), and 18B (blue). Other colors, numbers of colors, or combinations of colors may be used for the phosphor pixels 18.

[0020] When forming a phosphor-converted LED array using these methods, phosphor pixels 18 on a layered carrier assembly are aligned and contacted with corresponding semiconductor LED pixels 14 in a pixelated semiconductor LED die array, for example, which may have a thin-film flip-chip (TFFC) architecture. Selected phosphor pixels 18 on the carrier assembly can then be attached to the corresponding semiconductor LED pixels 14 and released from the substrate by powering (activating) the corresponding semiconductor LED pixels 14 to heat the selected phosphor pixels 18 to a desired temperature. This releases the thermally released adhesive 32 that attaches the selected phosphor pixels 18 to the carrier substrate 30 and cures or partially cures the adhesive 20 on the selected phosphor pixels 18 in contact with the corresponding semiconductor LED pixels 14. Thus, the attachment step selectively bonds the pixels 18 of the phosphor layer to the corresponding pixels 14 of the pixelated semiconductor LED die array. The layered carrier assembly and unbonded phosphor pixels 18 can then be removed, for example, by attaching (e.g., laminating) a processing strip to the back side of the substrate 30.

[0021] If UV-release adhesive 32 is used instead of thermal-release adhesive, or if UV-release adhesive 32 is used in addition to thermal-release adhesive, then UV light emitted by the GaN LED can be released from the carrier 30 to the corresponding phosphor pixel 18.

[0022] This process can be repeated for phosphor pixel arrays of different colors to fabricate a multicolor phosphor-converting LED array 10. The final device structure can be further heated so that the silicone adhesive firmly bonds the phosphor pixels 18 to the semiconductor LED pixels 14.

[0023] By using a pre-formed phosphor layer, color control and yield can be highly controlled through pre-testing and integration of only known good phosphors.

[0024] Figure 1AThis is a schematic cross-sectional view of a close-packed array 10 of multicolor phosphor-converting LEDs on a substrate 12 fabricated using the methods disclosed herein. The side view shows GaN LEDs 14 attached to the substrate 12 via metal interconnects 17 (e.g., gold-gold interconnects or solder attached to copper micropillars) and metal interconnects 16. Phosphor pixels 18 are attached to their respective GaN LEDs 14 via an adhesive layer 20, which may be, for example, a silicone adhesive layer. The pixels 18 of the phosphor array may have mirrors or diffuse scattering layers 22 coated on their sides. In some examples, phosphor pixels 18 may have the same height and the same single color; in some examples, phosphor pixels may have varying heights / thicknesses or different colors. In multicolor devices (based on desired color points), varying phosphor thicknesses are advantageous for the sequential nature of the phosphor attachment process; typically, the phosphor pixel 18 with the last color attached will be the thickest (highest). In some examples, an optional buffer layer or transparent layer 24 may be disposed on top of the phosphor pixels 18. This buffer or transparent layer 24 can help retain color dots, flatten out any thickness or height variations between phosphor pixels 18, or protect phosphor pixels during subsequent processing steps (e.g., removing excess material applied to phosphor pixels 18 as a reflective side coating).

[0025] As outlined above and further explained below with reference to the figures, the self-heating of the semiconductor LED pixel 14 and the corresponding phosphor pixel 18 during the operation of the semiconductor LED chip is used to selectively combine the pixel 18 from the phosphor array to the corresponding GaN LED pixel 14 to form a phosphor-converted LED array.

[0026] In some examples of display applications, LED displays comprise a large number of display pixels. In some examples (e.g., such as...) Figure 1B In the case of a single display pixel (e.g., in the middle), each display pixel comprises a single semiconductor LED pixel 14 and a corresponding phosphor pixel 18R, 18G, or 18B of a single color (red, green, or blue). Each display pixel provides only one of the three colors. In some examples (e.g., such as...), Figure 1CEach display pixel comprises a plurality of semiconductor LED pixels 14 and a plurality of corresponding phosphor pixels 18 of a plurality of colors. In the example shown, each display pixel comprises a 3×3 array of semiconductor pixels 14; three of those LED pixels have red phosphor pixels 18R, three have green phosphor pixels 18G, and three have blue phosphor pixels 18B. Therefore, each display pixel can produce any desired color combination. In the example shown, the spatial arrangement of the phosphor pixels 18 of different colors differs among the display pixels; in some examples (not shown), each display pixel may have the same arrangement of phosphor pixels 18 of different colors.

[0027] Figure 2 This is a process flow diagram of the example method of the present invention. Figure 3A , 3B Figures 3C and 3C show three consecutive sequences of the device structure at each stage of attachment of the phosphor pixel 18.

[0028] In step 102, a segmented phosphor array is created on a carrier 30 coated with a releasable adhesive 32 (e.g., a thermally release layer). This array can be formed by cutting the phosphor-containing layer or by other methods such as photolithography or ablation processes. The phosphor layer material can be, for example, phosphor / silicone, ceramic phosphor, phosphor in glass, or phosphor on glass; other suitable phosphor materials can be used. Before or after the phosphor layer segmentation step, the surface of the phosphor layer (or each phosphor pixel 18) opposite to the surface attached to the carrier 30 is coated with a thermally activated adhesive 20 (e.g., LED-grade silicone or epoxy adhesive, which exhibits low adhesion strength / G' at room temperature and increased adhesion strength at higher temperatures).

[0029] The carrier 30 may be, for example, a PET substrate, a sacrificial polymer substrate, a glass substrate, or a silicon substrate. The releasable adhesive layer 32 may be a thermally or UV-activated releasable adhesive. The thermally or UV-activated releasable adhesive 32 has a shear storage modulus G' > 300 kPa at room temperature, which decreases to below 300 kPa at a given elevated temperature to achieve adhesion to the carrier substrate 30. Suitable layered carrier assemblies—such as Nitto Revalpha and Adwill D510—comprise a substrate 30 and a thermally activated releasable adhesive 32. The phosphor layer comprises a segmented array of phosphor pixels 18 of a single color, and a partially cured or highly viscous silicone adhesive 20 disposed on the surface of the phosphor pixels 18 opposite to the carrier substrate 30.

[0030] During mechanical or chemical segmentation, the phosphor layer can be cut into individual M×N arrays, resulting in primary and secondary gaps within the phosphor layer. The primary gaps completely penetrate the carrier 30 to divide the phosphor layer into arrays (e.g., corresponding to display pixels comprising multiple semiconductor LED pixels 14). The secondary gaps cut through the phosphor but stop within the carrier layer 30, thus creating multiple phosphor pixels 18 in each individual array.

[0031] In step 104, the segmented phosphor array is aligned with the semiconductor LED array such that a single phosphor pixel 18 is aligned with a corresponding pixel 14 in the semiconductor LED array. In step 106, the phosphor pixels 18 and LED pixels 14 are placed in contact with each other and optionally weakly bonded. In step 106, a selected subset of the pixels in the LED array is electrically turned on. During this operation, the surface of the selected LED pixels is rapidly heated to a sufficiently high temperature (e.g., 100°C to 150°C) to reflow the thermally activated adhesive 20 between the semiconductor LED pixels 14 and the corresponding phosphor pixels 18, thereby creating a strong bond between each selected LED pixel 14 and the corresponding phosphor pixel 18 in step 108. Simultaneously, downconversion in the phosphor layer causes additional heating of the phosphor pixels 18, reaching temperatures such as 150°C to 200°C. This causes the phosphor pixels 18 to release from the heat release layer 32 on the carrier 30.

[0032] In step 110, the carrier is removed. A corresponding subset of the phosphor pixels 18 is bonded to the semiconductor LED pixels 14 that operated during step 106, while the remainder remain on the carrier 30 and are removed from the LED array.

[0033] The described method in Figure 3A Schematic illustration, Figure 3AA carrier layer 30 is shown, to which blue phosphor pixels 18B are attached and aligned above an array of semiconductor LED pixels 14 on a substrate 12. The carrier assembly and semiconductor dies are placed together such that adhesive 20 is positioned between and in contact with the light-output surfaces of each phosphor pixel 18B and each corresponding LED pixel 14. In step 106, some LED pixels 14 are electrically activated (indicated by white arrows), which heats the activated LED pixels 14 and their corresponding phosphor pixels 18B. In step 108, the increased temperature causes adhesive 20 to cure, or at least partially cure, while adhesive 32 is released. Note that in the figure, solid black layers 20 or 32 indicate uncured, released, or non-adhesive adhesive, while white layers 20 or 32 indicate cured or adhered adhesive. In step 110, the carrier substrate 30 is removed. Phosphor pixels 18B remain attached to the corresponding LED pixels 14 that were activated in step 106, and are removed from those LED pixels 14 that were not activated.

[0034] Steps 102 to 110 can be repeated to attach phosphor pixels 18 of other colors. In the example shown, blue phosphor pixels 18B are attached to... Figure 3A After some LED pixels 14, in Figure 3B In this process, a carrier substrate with green phosphor pixels 18G is used to attach the green phosphor pixels 18G to certain LED pixels 14 that have not yet been attached with blue phosphor pixels 18B. The carrier 30 has a pattern of phosphor pixels 18G that complements the arrangement of blue phosphor pixels 18B already attached to the LED pixels 14. With the green phosphor pixels 18G on the LED pixels 14, certain LED pixels 14 are activated to cure adhesive 20 and release adhesive 32. The carrier 30 is removed, thereby removing the phosphor pixels 18G from the unactivated LED pixels and leaving the phosphor pixels 18G attached to those activated LED pixels 14. This process can be repeated (e.g., ...). Figure 3C (in the middle), to attach red phosphor pixels 18R to those pixels that have not yet been attached to blue or green phosphor pixels 18B or 18G. The order of colors is just an example; any order can be used, and different orders can be advantageously used to produce a complementary arrangement of phosphor pixels 18 on carrier 30, which is required for the attachment of second and subsequent color phosphor pixels 18.

[0035] Figure 4A and Figure 4B The schematic diagram illustrates the attachment order of three parallel phosphor pixels, each order corresponding to... Figures 3A to 3C The order shown is similar. As described above and as... Figure 3AAs shown, phosphor pixels of the first color are attached to certain LED pixels 14 (red pixels 18R in the left order, green pixels 18G in the middle order, and blue pixels 18B in the right order). After removing the carriers 30 and their remaining phosphor pixels 18, each carrier 30 is shifted to a different order (by...). Figure 4A (As indicated by the diagonal arrows in the diagram), the pattern of its missing phosphor pixels 18 (those left to be attached to LED pixels 14) is the complementary pattern required to attach the second color to the same arrangement of LED arrays that already have attached phosphor pixels 18. As described above and as... Figure 3B As shown, after attaching the second-color phosphor pixels 18 to some LED pixels 14, the carrier 30 is moved again to attach the third-color phosphor pixels, as... Figure 3C As shown in the image.

[0036] Figure 4B The top view shown illustrates the work of Figure 4A An example of the phosphor pixel arrangement order resulting from the order of the phosphors, and with Figure 1B The example shown is similar. Starting with a bare 3×3 array of semiconductor LED pixels 14, phosphor pixels of the first color are attached in a first pattern (diagonal in this example) as described above; the first pattern is the same for the three different first colors on the three different LED arrays. After the first color attachment sequence, each array of phosphor pixels 18 leaves gaps corresponding to those left behind and can now be fitted onto one of the other LED arrays with the first color attached. Phosphor pixels 18 of the second color are attached in a second pattern as described above; the second pattern is the same for the three different second colors on the three different LED arrays. With the removal of the second set of phosphor pixels 18, each carrier can now be fitted over the attached phosphor pixels 18 of the two previously attached colors. Finally, in some examples, the entire LED array can be covered with phosphor pixels 18 (as shown). In other examples (not shown), some LED pixels 14 may not have corresponding phosphor pixels 18 left behind; this arrangement may be suitable, for example, when the direct output of the LED pixels 14 is one of the desired colors of the display. Although a 3×3 LED array is shown in the example, the disclosed method can be used to fabricate multicolor phosphor-converted LED arrays of any size or number of pixels.

[0037] In one particular example, the silicone / phosphor film is fully cured and then laminated onto a PET substrate 30 coated with a heat-release adhesive 22. A thin layer of silicone adhesive 20 is deposited, for example, on the surface of the phosphor film via spin coating, followed by a brief baking step to remove excess solvent. The phosphor film / PET stack is then cut into a 3×3 array, with every three saw lines completely cutting through the PET to unify the array (the other saw lines cut through the phosphor but stop in the PET layer). The array is then aligned and attached to the pixelated TFFC die using a pick-and-place tool. No elevated temperature or force is used during the attachment process, resulting in a weak bond between the silicone adhesive on the die and the phosphor pixels 18. Electrical contacts are then made to power the die-LED pixels 14 of the selected pattern, which operate at a set current for a certain duration (4 A / mm in the case of the device shown in Figure 4). 2 (Continued for 15 seconds). The tape is laminated onto the top of the PET carrier 30 and then used to remove the PET carrier 30 and the unbonded phosphor pixels 18.

[0038] As described above, in some examples, the release adhesive 32 can be UV-released. In examples where the light output of the semiconductor LED pixel 14 has a wavelength suitable for the release adhesive—for example, a UV GaN LED—a UV-released adhesive 32 can be used.

[0039] Figures 5A to 5C The phosphor pixel attachment order shown is... Figures 3A to 3C The phosphor pixel attachment order shown is similar, except that the phosphor pixels 18 of different colors have different thicknesses. In some examples, this thickness difference may occur due to the different optical properties of the different phosphors (e.g., absorption coefficient or conversion efficiency). In some examples, different thicknesses can contribute to the phosphor attachment order disclosed herein. If the phosphor pixels 18 of different colors are attached in order from thinnest to thickest (e.g., ... Figures 5A-5C In each subsequent attachment stage, a gap exists between the carrier substrate 30 and the phosphor pixel 18 already attached to the corresponding LED pixel 14. This can, for example, help ensure that the subsequently attached phosphor pixel 18 can contact the corresponding LED pixel (i.e., without being interfered with by an excessively thick phosphor pixel 18 already attached to the LED pixel 14), or it can help avoid potentially undesirable contact between the attached phosphor pixel 18 and the carrier 30, or the release of adhesive residue thereon.

[0040] Although the heat-release carrier 30 is removed at the end of the attachment process, the disclosed method of the invention results in discrete segments of a thermally activated adhesive layer 20 between the light output surfaces of each attached phosphor pixel 18 and the corresponding semiconductor LED pixel 14. Each adhesive layer segment 20 is separated from other such segments between other pairs of phosphor pixels 18 and LED pixels 14. The presence of these discrete adhesive layer segments 20, and the segmentation of complete alignment between both the adhesive layer 20 and the phosphor pixel 18 (i.e., alignment with the underlying LED pixel 14), can indicate the use of the disclosed method of the invention. Other indicators of those methods may include different thicknesses (i.e., heights) of the phosphor pixels, depending on the number of attachment steps used to attach phosphor pixels of different colors. Finally, the metal traces / ties used during the attachment process to electrically activate the appropriate pixels can also indicate the use of the disclosed method of the invention.

[0041] This disclosure is illustrative and not restrictive. Further modifications will be apparent to those skilled in the art in light of this disclosure and are intended to fall within the scope of the appended claims. Those skilled in the art can extend the disclosed inventive apparatus and methods to vertical thin-film (VTF) and similar LED architectures.

[0042] In addition to the foregoing, the following example embodiments fall within the scope of this disclosure or the appended claims.

[0043] Example 1. A light-emitting device comprising: (a) a semiconductor LED array including a plurality of semiconductor LED pixels; (b) a plurality of corresponding phosphor pixels of various colors, wherein each phosphor pixel is located above the light-emitting surface of a corresponding semiconductor LED pixel in the semiconductor LED array; and (c) corresponding discrete segments of thermosetting adhesive between each phosphor pixel and the corresponding semiconductor LED pixel, which attach the phosphor pixel to the corresponding semiconductor LED pixel, wherein each discrete segment of thermosetting adhesive is separate from other discrete segments of thermosetting adhesive between other phosphor pixels and corresponding semiconductor LED pixels in the array.

[0044] Example 2. The light-emitting device according to Example 1 further includes one or more metal traces or rods arranged and connected to enable selective electrical operation of selected semiconductor LED pixels.

[0045] Example 3. A light-emitting device according to any one of Examples 1 or 2, wherein the phosphor pixels exhibit different thicknesses.

[0046] Example 4. The light-emitting device according to any one of Examples 1 to 3, wherein the thermosetting adhesive exhibits a curing temperature between about 100°C and about 150°C.

[0047] Example 5. The light-emitting device according to any one of Examples 1 to 4, wherein the thermosetting adhesive is a silicone resin.

[0048] Example 6. A light-emitting device according to any one of Examples 1 to 5, wherein the thermosetting adhesive has a refractive index between about 1.4 and about 1.6.

[0049] Example 7. The light-emitting device according to any one of Examples 1 to 6, wherein the phosphor pixel comprises one or more of phosphor / silicone, ceramic phosphor, phosphor in glass, or phosphor on glass.

[0050] Example 8. A method for manufacturing a light-emitting device according to any one of Examples 1 to 7, the method comprising: (A) positioning a phosphor structure on a semiconductor LED array, wherein each phosphor pixel is aligned with a corresponding semiconductor LED pixel of the array, and wherein a corresponding segment of adhesive is located between and in contact with the light output surfaces of each phosphor pixel and the corresponding semiconductor LED pixel; and (B) electrically operating selected semiconductor LED pixels to emit light, and heating the corresponding phosphor pixel to a temperature at which at least partially curing the corresponding discrete segment of adhesive and bonding each of the selected semiconductor LED pixels to the corresponding phosphor pixel.

[0051] Example 9. A method for manufacturing a light-emitting device, the method comprising: (A) positioning a phosphor structure comprising a plurality of phosphor pixels on a semiconductor LED array comprising a plurality of semiconductor LED pixels, wherein each phosphor pixel is aligned with a corresponding semiconductor LED pixel of the array, the phosphor structure having a layer of thermally curable adhesive such that, when the phosphor structure is positioned on the semiconductor LED array, corresponding segments of the adhesive are located between and in contact with the light output surfaces of each phosphor pixel and the corresponding semiconductor LED pixel; and (B) electrically operating selected semiconductor LED pixels to emit light, and heating the corresponding phosphor pixel to a temperature at least partially curing the corresponding discrete segments of the adhesive and bonding each of the selected semiconductor LED pixels to the corresponding phosphor pixel.

[0052] Example 10. According to the method of Example 9, the thermosetting adhesive exhibits a curing temperature between about 100°C and about 150°C.

[0053] Example 11. The method according to any one of Examples 9 or 10, wherein the thermosetting adhesive is a silicone resin.

[0054] Example 12. The method according to any one of Examples 9 to 11, wherein the thermosetting adhesive has a refractive index between about 1.4 and about 1.6.

[0055] Example 13. The method according to any one of Examples 9 to 12, wherein the phosphor layer comprises one or more of phosphor / silicone, ceramic phosphor, phosphor in glass, or phosphor on glass.

[0056] Example 14. The method according to any one of Examples 9 to 13, wherein (i) the phosphor structure includes a substrate, (ii) the surface of the phosphor pixel opposite the semiconductor LED array is attached to the substrate by a thermally release adhesive, and (iii) selected semiconductor LED pixels in the semiconductor LED pixels are operated to emit light and to heat the corresponding phosphor pixel, thereby releasing the corresponding phosphor pixel from the substrate.

[0057] Example 15. According to the method of Example 14, the heat-release adhesive exhibits a release temperature between about 150°C and about 220°C.

[0058] Example 16. The method according to any one of Examples 14 or 15 further includes removing the substrate and those phosphor pixels that are not released from the substrate from the semiconductor LED array.

[0059] Example 17. The method according to any one of Examples 9 to 13, wherein (i) the phosphor structure includes a substrate, (ii) the surface of the phosphor pixel opposite the semiconductor LED array is attached to the substrate by a UV-release adhesive, and (iii) selected semiconductor LED pixels in the semiconductor LED pixels are operated to emit UV light, thereby releasing the corresponding phosphor pixel from the substrate.

[0060] Example 18. The method according to Example 17 further includes removing the substrate and those phosphor pixels that are not released from the substrate from the semiconductor LED array.

[0061] Example 19. A method according to any one of Examples 9 to 18, wherein the phosphor pixels of the phosphor structure have a first color, the method further comprising: (C) positioning a second phosphor structure on the phosphor pixels of the first color in combination with a semiconductor LED array, the second phosphor structure comprising a plurality of phosphor pixels having a second color different from the first color, wherein each phosphor pixel of the second color is aligned with a corresponding semiconductor LED pixel in the array that is not bonded to a phosphor pixel of the first color, the second phosphor structure having a layer of thermosetting adhesive such that, when the second phosphor structure is located on the semiconductor LED array, corresponding segments of the adhesive are located between and in contact with each phosphor pixel of the second color and the corresponding semiconductor LED pixel; and (D) electrically operating selected semiconductor LED pixels to emit light, and heating the corresponding phosphor pixels of the second color to a temperature at least partially curing the corresponding discrete segments of the adhesive and bonding each of the selected semiconductor LED pixels to the corresponding phosphor pixel of the second color.

[0062] Example 20. The method according to Example 19, wherein (i) the second phosphor structure includes a second substrate, (ii) the surface of a second-color phosphor pixel opposite to the semiconductor LED array is attached to the second substrate by a thermally releasable adhesive, and (iii) selected semiconductor LED pixels in the semiconductor LED pixels are operated to emit light and to heat the corresponding second-color phosphor pixel, thereby releasing the corresponding second-color phosphor pixel from the second substrate.

[0063] Example 21. The method according to Example 20 further includes removing the second substrate and those second-color phosphor pixels that are not released from the second substrate from the semiconductor LED array.

[0064] Example 22. The method according to Example 19, wherein (i) the second phosphor structure includes a second substrate, (ii) the surface of a second-color phosphor pixel opposite to the semiconductor LED array is attached to the second substrate by a UV-release adhesive, and (iii) selected semiconductor LED pixels are operated to emit UV light, thereby releasing the corresponding second-color phosphor pixel from the second substrate.

[0065] Example 23. The method according to Example 22 further includes removing the second substrate and those second-color phosphor pixels that are not released from the semiconductor LED array.

[0066] Example 24. The method according to any one of Examples 19 to 23, wherein the phosphor pixels of the second color are thicker than the phosphor pixels of the first color.

[0067] It is intended that equivalents of the disclosed exemplary embodiments and methods should fall within the scope of this disclosure or the appended claims. It is also intended that the disclosed exemplary embodiments and methods and their equivalents may be modified while remaining within the scope of this disclosure or the appended claims.

[0068] In the foregoing specific embodiments, various features from several example embodiments may be combined for the purpose of streamlining the disclosure. This method of disclosure should not be construed as reflecting an intention that any claimed embodiment requires more features than expressly listed in the corresponding claim. Rather, as reflected in the appended claims, the inventive subject matter may lie in fewer than all features of a single disclosed example embodiment. Therefore, this disclosure should be interpreted as implicitly disclosing any embodiment having any suitable subset of one or more features—features shown, described, or claimed in this application—including those subsets that may not be expressly disclosed herein. A “suitable” subset of features includes only features that are neither incompatible nor mutually exclusive with any other features relative to that subset. Therefore, the appended claims are thus incorporated in their entirety into the specific embodiments, with each claim itself serving as a separately disclosed embodiment. Furthermore, each of the appended dependent claims should be interpreted—simply for the purpose of disclosure by incorporating the claims into the specific embodiments—as if written in multiple dependent forms and subordinate to all the foregoing claims that do not contradict them. It should also be noted that the cumulative scope of the appended claims may, but does not necessarily, cover all the subject matter disclosed in this application.

[0069] The following interpretations shall apply to this disclosure and the appended claims. Unless expressly stated otherwise, the words “comprising,” “including,” “having,” and variations thereof, wherever they appear, shall be understood as open-ended terms meaning as if a phrase such as “at least” were appended after each instance. The article “a” shall be interpreted as “one or more” unless “only one,” “single,” or other similar limitation is expressly stated or implied in the particular context; similarly, the article “the” shall be interpreted as “one or more of…” unless “only one of…,” “single of…,” or other similar limitation is expressly stated or implied in the particular context. The conjunction “or” shall be interpreted as inclusive unless: (i) it is otherwise expressly stated, for example, by using “or…or…,” “only one of…,” or similar language; or (ii) two or more of the listed alternatives are understood or disclosed (implicitly or explicitly) as incompatible or mutually exclusive in the particular context. In the latter case, “or” will be understood to cover only those combinations involving non-mutually exclusive alternatives. In one example, each of “dog or cat,” “one or more of dogs or cats,” and “one or more dogs or cats” will be interpreted as one or more dogs without any cats, or one or more cats without any dogs, or one or more of each. In another example, each of “dog, cat, or mouse,” “one or more of dogs, cats, or mice,” and “one or more dogs, cats, or mice” will be interpreted as (i) one or more dogs without any cats or mice, (ii) one or more cats without any dogs or mice, (iii) one or more mice without any dogs or cats, (iv) one or more dogs and one or more cats without any mice, (v) one or more dogs and one or more mice without any cats, (vi) one or more cats and one or more mice without any dogs, or (vii) one or more dogs, one or more cats, and one or more mice. In another example, each of “two or more of dogs, cats or mice” or “two or more dogs, cats or mice” will be interpreted as (i) one or more dogs and one or more cats, without any mice, (ii) one or more dogs and one or more mice, without any cats, (iii) one or more cats and one or more mice, without any dogs, or (iv) one or more dogs, one or more cats, and one or more mice; “three or more”, “four or more” and so on will be interpreted similarly.

[0070] For the purposes of this disclosure or the appended claims, when using terms related to numerical quantities—such as “approximately equal to,” “substantially equal to,” “greater than about,” “less than about,” etc.—the standard conventions relating to measurement precision and significant figures shall apply, unless a different interpretation is explicitly stated. For zero quantities described by phrases such as “substantially prevent,” “substantially non-existent,” “substantially eliminated,” “approximately equal to zero,” “negligible,” etc., each such phrase should indicate that the quantity in question has been reduced or diminished to such an extent that, for practical purposes, the overall behavior or performance of the disclosed or claimed apparatus or method is indistinguishable from that which would have occurred if the zero quantity had been completely removed, precisely equal to zero, or otherwise precisely zero.

[0071] For the purposes of this disclosure and the appended claims, any designation of elements, steps, limitations, or other parts of the embodiments, examples, or claims (e.g., first, second, third, etc., (a), (b), (c), etc., or (a), (b), (c), etc.) is merely for clarity and should not be construed as implying any kind of order or priority of such designations. If any such order or priority is intentional, it will be expressly enumerated in the embodiments, examples, or claims, or in some instances, it will be implicit or inherent based on the specific content of the embodiments, examples, or claims. In the appended claims, if it is desired to invoke the provisions of 35 USC §112(f) in an apparatus claim, then the word “apparatus” will appear in that apparatus claim. If it is desired to invoke those provisions in a method claim, then the word “for the step of…” will appear in the method claim. Conversely, if the words “apparatus” or “for the step of…” do not appear in the claim, then the provisions of 35 USC §112(f) are not intended to be invoked in that claim.

[0072] If any one or more disclosures are incorporated herein by reference and such incorporated disclosures conflict in whole or in part with this disclosure, or differ in scope from this disclosure, then this disclosure shall prevail as to the extent of the conflict, the broader disclosure, or the broader definitions of terms. If any of such incorporated disclosures conflict in whole or in part with each other, then the later-date disclosure shall prevail as to the extent of the conflict.

[0073] Abstracts are provided as needed to assist those searching for specific topics within the patent literature. However, these abstracts are not intended to imply that any particular claim necessarily covers any element, feature, or limitation listed therein. The scope of the subject matter covered by each claim should be determined solely by the enumeration of that claim.

Claims

1. A method of manufacturing a light emitting device, the method comprising: positioning a phosphor structure comprising a plurality of phosphor pixels on a semiconductor LED array comprising a plurality of semiconductor LED pixels, with each phosphor pixel aligned with a corresponding semiconductor LED pixel of the array, the phosphor structure having a layer of heat-curable adhesive thereon such that, with the phosphor structure positioned on the semiconductor LED array, a corresponding segment of the adhesive is between and in contact with each phosphor pixel and the light output surface of the corresponding semiconductor LED pixel; and electrically operating selected ones of the semiconductor LED pixels to emit light and to heat the corresponding phosphor pixels to a temperature that at least partially cures the corresponding discrete segment of the adhesive and bonds each of the selected semiconductor LED pixels to the corresponding phosphor pixel.

2. The method of claim 1, wherein the heat-cured adhesive exhibits a cure temperature between 100°C and 150°C.

3. The method of claim 1, wherein the heat-cured adhesive is a silicone.

4. The method of claim 1, wherein the heat-cured adhesive has an index of refraction between 1.4 and 1.

6.

5. The method of claim 1, wherein the phosphor layer comprises one or more of a phosphor / silicone, a ceramic phosphor, a phosphor in glass, or a phosphor on glass.

6. The method of claim 1, wherein (i) the phosphor structure comprises a substrate, (ii) a surface of the phosphor pixels opposite the semiconductor LED array is attached to the substrate by a heat-releasable adhesive, and (iii) operating the selected ones of the semiconductor LED pixels to emit light and to heat the corresponding phosphor pixels releases the corresponding phosphor pixels from the substrate.

7. The method of claim 6, wherein the heat-releasable adhesive exhibits a release temperature between 150°C and 220°C.

8. The method of claim 6, further comprising removing the substrate and those phosphor pixels that are not released from the substrate from the semiconductor LED array.

9. The method of claim 1, wherein (i) the phosphor structure comprises a substrate, (ii) a surface of the phosphor pixels opposite the semiconductor LED array is attached to the substrate by a UV-releasable adhesive, and (iii) operating the selected ones of the semiconductor LED pixels to emit UV light releases the corresponding phosphor pixels from the substrate.

10. The method of claim 9, further comprising removing the substrate and those phosphor pixels that are not released from the substrate from the semiconductor LED array.

11. The method of any one of claims 1-10, wherein the phosphor pixels of the phosphor structure all have a first color, the method further comprising: positioning a second phosphor structure on the array of semiconductor LEDs and the combined phosphor pixels of the first color, the second phosphor structure comprising a plurality of phosphor pixels all having a second color different from the first color, wherein each phosphor pixel of the second color is aligned with a corresponding semiconductor LED pixel that is not combined to the array of phosphor pixels of the first color, the second phosphor structure having a layer of heat-curable adhesive thereon such that, with the second phosphor structure positioned on the array of semiconductor LEDs, a corresponding segment of the adhesive is between and in contact with each phosphor pixel of the second color and the corresponding semiconductor LED pixel; and electrically operating selected ones of the semiconductor LED pixels to emit light and to heat corresponding phosphor pixels of the second color to a temperature that at least partially cures the corresponding discrete segment of the adhesive and bonds each of the selected semiconductor LED pixels to the corresponding phosphor pixel of the second color.

12. The method of claim 11, wherein (i) the second phosphor structure comprises a second substrate, (ii) a surface of the phosphor pixels of the second color opposite the array of semiconductor LEDs is adhered to the second substrate by a heat-releasable adhesive, and (iii) operating selected ones of the semiconductor LED pixels to emit light and to heat corresponding phosphor pixels of the second color releases the corresponding phosphor pixels of the second color from the second substrate.

13. The method of claim 12, further comprising removing the second substrate and those of the phosphor pixels of the second color that are not released from the second substrate from the array of semiconductor LEDs.

14. The method of claim 11, wherein (i) the second phosphor structure comprises a second substrate, (ii) a surface of the phosphor pixels of the second color opposite the array of semiconductor LEDs is adhered to the second substrate by a UV-releasable adhesive, and (iii) operating selected ones of the semiconductor LED pixels to emit UV light releases the corresponding phosphor pixels of the second color from the second substrate.

15. The method of claim 14, further comprising removing the second substrate and those of the phosphor pixels of the second color that are not released from the second substrate from the array of semiconductor LEDs.

16. The method of claim 11, wherein the phosphor pixels of the second color are thicker than the phosphor pixels of the first color.

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