A wirebond pad 107 is affixed to the semiconductor-containing structure 106x. The wirebond pad 107 is typically light absorbing and generally only slightly larger in diameter than a wire being attached thereto to connect to a substrate, e.g., a device substrate. The wirebond pad 107 can extend somewhat over a top interior of the semiconductor-containing structure 106x to help spread current. Current spreading can be helped with the use of a transparent conducting oxide (TCO, such as ITO) that is electrically coupled to the wirebond pad 107.

In FIG. 8, die 101v is representative of a flip chip LED die, comprising: (second) semiconductor-containing structure 106v and (second) underbump metallizations (UBMs) 108v.1 and 108v.2. FIG. 8 is analogously representative of die 101z of FIGS. 9-14. The semiconductor-containing structure 106v has a (second) semiconductor-containing structure height 115v spanning from a (second) growth surface 114v to a (second) deposition surface 116v. The underbump metallizations (UBMs) 108v.1 and 108v.2 each have a (second) UBM height 117v spanning from respective (second) UBM attachment surface 118x to (second) UBM device surface 120v. The second UBM device surfaces 120v of the respective second UBMs 108v.1 and 108v.2 are disposed on the second deposition surface 116v of the second semiconductor-containing structure 106v. In one or more embodiments, the flip chip LED die include a nitride light emitting layer (e.g., GaN or InGaN). In one or more embodiments, the flip chip LED die are effective to emit blue or green light. In one or more embodiments, the flip chip configuration includes a sapphire (growth) substrate.

Within the semiconductor-containing structures 106x and 106v (and analogously 106z), according to one or more embodiments, a transparent substrate may be present, comprising any suitable substrate known to the skilled artisan, on which semiconductor epitaxial layers are grown. In one or more embodiments, the transparent substrate comprises one or more of sapphire, silicon carbide, silicon (Si), quartz, magnesium oxide (MgO), zinc oxide (ZnO), spinel, and the like. In one or more embodiments, the transparent substrate is not patterned prior to the growth of an epi-layer. Thus, in some embodiments, the transparent substrate is not patterned and can be characterized as flat or substantially flat. In other embodiments, the transparent substrate is patterned, e.g., patterned sapphire substrate (PSS).

In some embodiments, the transparent substrate can support an epitaxially grown or deposited semiconductor N-layer. A semiconductor p-layer can then be sequentially grown or deposited on the N-layer, forming an active region at the junction between layers. Semiconductor materials capable of forming high-brightness light emitting devices can include, but are not limited to, Group III-V semiconductors, particularly binary, ternary, and quaternary alloys of gallium, aluminum, indium, and nitrogen, also referred to as III-V nitride materials. In some embodiments, the III-nitride material comprises one or more of gallium (Ga), aluminum (Al), and indium (In). Thus, in some embodiments, the semiconductor layer comprises one or more of gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), gallium aluminum nitride (GaAlN), gallium indium nitride (GaInN), aluminum gallium nitride (AlGaN), aluminum indium nitride (AlInN), indium gallium nitride (InGaN), indium aluminum nitride (InAlN), and the like. In one or more specific embodiments, the semiconductor layer comprises gallium nitride and is an n-type layer.

It will be appreciated by one of skill in the art that the transparent substrate may include one or more material layers (e.g., Ill-nitride, and the like), vias, and the like thereon. In one or more embodiments, the substrate may include semiconductor layers including an N-type layer, an active layer, and a P-type layer that is capable of emitting light when electrically powered.

Embodiments of arrays herein include at least three sets of LED die of differing colors and/or differing configurations among at least two sets. In one or more embodiments, a first set of LED die comprise a vertical configuration, and the second set of LED die comprise a flip chip configuration, and the third set of LED die comprise either a vertical configuration or a flip chip configuration. In a detailed embodiment, the vertical configuration comprises a vertical thin film (VTF) configuration. In a detailed embodiment, the flip chip configuration comprises a thin film flip chip configuration (TFFC). In a detailed embodiment, the vertical configuration comprises a vertical thin film (VTF) configuration and the flip chip configuration comprises a thin film flip chip configuration (TFFC). In one or more embodiments, a first die height, a second die height, and a third die height of the LED arrays have dimensions within 10 micrometers of each other, and more preferred within 5 micrometers of each other.

FIGS. 9 to 14 illustrate views of LED intermediate structures 100A to 100D during preparation of an LED device 150A or 150B following the process flow illustrated for method 10 of FIG. 1, method 1A.1 of FIG. 2, and method 1B.1 of FIG. 4. FIGS. 9 to 14 are cross-section views of the light emitting device. In FIGS. 9 to 14, the LED semiconductor-containing structures are the same height or essentially the same height, in which case no additional operations are needed to compensate UBMs for height differentials. For illustration purposes, a first set of LED die comprise a vertical configuration 101x, and the second and third sets of LED die 101v and 101z comprise a flip chip configuration.

Assembling the sets of the LED die on a support at operation 20 of FIG. 1 yields intermediate LED structure 100A of FIG. 9. In one or more embodiments, vertical configuration LED semiconductor-containing structure 106x and flip chip LED semiconductor-containing structures 106v and 106z are obtained at operation 2.1 and processed as-applicable in accordance with FIG. 2. Vertical configuration LED die 101x (see also FIG. 7) and the flip chip LED die 101v and 101z (see also FIG. 8) are accordingly provided at operation 1. In one or more embodiments, the respective LED die include: at least one electrical contact, otherwise known as underbump metallizations (UBMs), 108x, 108v, 108z; and a semiconductor-containing structure 106x, 106v, 106z. The semiconductor-containing structure 106x of the vertical configuration LED die 101x further includes the wirebond pad 107.

The LED die 101x, 101v, and 101z are assembled onto a surface of the support 102 by way of their respective growth surfaces (e.g., 114x of FIG. 7 and 114 v of FIG. 8) at a distance “d” between adjacent semiconductor-containing structures 106x, 106v, 106z. In one or more embodiments, distance, d, is in a range of from 10 μm to 500 μm. In other embodiments, the LED semiconductor-containing structures 106x, 106v, 106z are spaced at least about 120 μm apart from an adjacent LED semiconductor-containing structure. It is understood that an entire assembly of the various LED die 101x, 101v, and 101z is done according to end-applications, and that the figures herein are not limiting as to which LED die are next to each other and in how many quantities.

In one or more embodiments of the LED die, the electrical contacts or UBMs 108x, 108v, 108z are on the respective deposition surfaces (e.g., 116x of FIG. 7 and 116v of FIG. 8), or top surface, of the semiconductor-containing structures 106x, 106v, and 106z. The UBMs 108x, 108v, 108z may comprise any suitable contact known to the skilled artisan. For example, in some embodiments, the UBM 108x, 108v, 108z may comprise one or more of a p-type contact or an n-type contact. In some embodiments, the UBMs 108x, 108v, 108z include a metal selected from one or more of copper (Cu), nickel (Ni), aluminum (Al), and gold (Au). In one or more embodiments, the UBMs herein, e.g., 108x, 108v, 108z are plated with gold (Au) through an immersion process to form gold plated electrical contacts. Gold (Au) plating is done by electroless nickel immersion gold (ENIG). It comprises electroless nickel plating, which is covered with a thin layer of immersion gold. In immersion gold, the gold layer is generated on the nickel layer through displacement. It continues until the generated gold layer is covered with nickel. This is why gold layer is very thin. This layer protects nickel from oxidation.

In one or more embodiments, the support 102 comprises any suitable support material. In one or more embodiments, the support 102 is removable. In one or more specific embodiments, the support 102 is a carrier tape. The tape can be dual side coated, such as one side having a pressure sensitive adhesive and another has a thermal release or UV sensitive adhesive which allows, when exposed to UV light, to release form the solid substrate.

Turning to FIG. 10 and intermediate structure 100B, at operation 25 of method 10, a reflective material 110 is disposed around sets of the LED die of the intermediate structure 100A. In one or more embodiments, the reflective material 110 is molded around the sets of the LED die. The reflective material 110 interacts with all surfaces of the LED die 101x, 101v, and 101z except for the surfaces (respective growth surfaces, e.g., 114x of FIG. 7 and 114 v of FIG. 8) that are on the support 102. With respect to the vertical configuration LED die 101x, a surface of the wirebond pad 107 facing/on the support 102 is protected from the reflective material 110.

In one or more embodiments, the reflective material 110 is highly reflective having a reflectance in a range of from 80% to 99%, including all values and subranges therebetween, including in a range of from 80% to 98%, or in a range of from 90% to 98%, or in a range of from 91% to 97%, or in a range of from 92% to 96%, or in a range of from 93% to 95%.

The reflective material 110 may comprise any suitable material known to the skilled artisan. In one or more embodiments, the reflective material is selected from one or more of silicone, titanium oxide (TiO₂), zirconium oxide (ZrO₂), aluminum oxide (Al₂O₃), or other metal oxides.

In some embodiments, the reflective material 110 includes a channel in which a thin vertical layer of light absorbing material resides. Without intending to be bound by theory, it is thought that the presence of the light absorbing material in the reflective material 110 facilitates reduced optical crosstalk between the LED die. The channel may extends into the reflective material to a desired depth towards the support 102. In some instances, the channel extends completely through the reflective material to the support 102. The channel may be formed by any suitable means known to the skilled artisan. In one or more embodiments, the reflective material 110 is sawed with a thin blade to create the channel between the LED die. Such opening may has a width, w, in a range of from 1 μm to 30 μm, or in a range of from 5 μm to 25 μm, or in a range of from 10 μm to 25 μm. The light absorbing material may comprise any suitable material known to the skilled artisan, for example, one or more of silicone, carbon, and a metal material.

Turning to FIG. 11 and intermediate structure 100C, at operation 30 of method 10, the reflective material 110 is planarized or ground to remove a portion thereof from a top surface of the intermediate structure 100B. The reflective material 110 may be removed by any suitable means including, but not limited to chemical mechanical planarization (CMP) and grinding. Upon planarizing, the reflective material 110 yields a reflective coating 111, which may have any suitable thickness. In one or more embodiments, the reflective coating 111 has a thickness in a range of from 40 μm to 60 μm.

In one or more embodiments, the reflective coating 111 serves not only to reflect light, but also serves as a structure element of an array (e.g., 113 of FIG. 13) by holding the LED die 101x, 101v, and 101z of the array together. Thus, in one or more embodiments, the LED die 101x, 101v, and 101z in the light-emitting diode (LED) array 113 are fixed in place by the reflective coating 111.

At operation 35, as illustrated in FIG. 12 by intermediate structure/array 100D, array 113 is removed from the support 102.

With reference to FIG. 13, intermediate structure 150A comprises the array 113, which is flipped and placed in proximity to a device substrate 103, for example a printed circuit board (PCB) or other suitable substrate for inclusion in a final system or device. The device substrate 103 has device contacts 109z, 109v, 109x that correspond to respective UBMs 108z, 108v, 108x. The device contacts 109z, 109v, 109x are in a coplanar configuration relative to each other.

At operation 40, the array 113 of FIG. 13 is attached to the device substrate 103 to prepare LED device 150B of FIG. 14. The device contacts 109z, 109v, 109x and respective UBMs 108z, 108v, 108x are bonded or otherwise soldered. A bonding wire 112 electrically connected to the device substrate 103 is affixed to the wirebond pad 107 of each of the vertical configuration LED die 101x.

FIG. 27 is a top plan view of array 113 of FIG. 13 prepared according to the method 10 of FIG. 1. As shown in FIG. 27, array 413 includes the vertical configuration LED die 401x including wirebond pad 407 and the flip chip die 401v, 401z, all of the die being held in place by the reflective coating material 411.

In one or more embodiments, the LED die 401x, 401v, and 401z are configured to emit different colors. In embodiments, the die 401x represents a first set of LED die each of a first die height and configured to emit a first color light, the die 401v represents a second set of LED die each of a second die height and configured to emit a second color light; and the die 401z represents a third set of LED die each of a third die height and configured to emit a third color light. As shown in cross-section of FIGS. 9-14, the plurality of LED die have a coplanar configuration and are spaced apart and retained by the reflective coating. In the embodiment of FIG. 27, the first set of LED die comprise a vertical configuration, and the second and third sets of LED die comprise a flip chip configuration.

FIGS. 15 to 20 illustrate views of LED intermediate structures 200A to 200D during preparation of an LED device 250A or 250B following the process flow illustrated for method 10 of FIG. 1, method 1A.2 of FIG. 3, and method 1B.2 of FIG. 5. FIGS. 15 to 20 are cross-section views of the light emitting device. In FIGS. 15 to 20, the LED semiconductor-containing structures include two differing heights among the three, in which case an additional operation is needed to compensate UBMs for height differentials. In one or more embodiments, two of the semiconductor-containing structures have essentially the same height, and are shorter in height than the other semiconductor-containing structure.

Assembling the sets of the LED die on a support at operation 20 of FIG. 1 yields intermediate LED structure 200A of FIG. 15. In one or more embodiments, red LED semiconductor-containing structure 206r is obtained at operation 2.2; green LED semiconductor-containing structure 206g and blue LED semiconductor-containing structure 206b are obtained at operation 6.2. The red LED semiconductor-containing structure 206r is processed as-applicable in accordance with FIG. 3. The green LED semiconductor-containing structure 206g and blue LED semiconductor-containing structure 206b are processed as-applicable in accordance with FIG. 5, including compensating for a difference in height of the semiconductor-containing structures compared to the red LED semiconductor-containing structure. In one or more embodiments, the respective LED die include: at least one electrical contact, otherwise known as underbump metallizations (UBMs), 208r, 208g, 208b; and a semiconductor-containing structure 206r, 206g, 206b. The semiconductor-containing structure 206r of the red LED die 201r further includes wirebond pad 207.

The LED die 201r, 201g, and 201b are assembled onto a surface of the support 202 by way of their respective growth surfaces (e.g., 114x of FIG. 7 and 114 v of FIG. 8) at a distance “d” between adjacent semiconductor-containing structures 206r, 206g, 206b. In one or more embodiments, distance, d, is in a range of from 10 μm to 500 μm. In other embodiments, the semiconductor-containing structure 206r, 206g, 206b are spaced at least about 120 μm apart from an adjacent LED semiconductor-containing structure. It is understood that an entire assembly of the various LED die 201r, 201g, and 201b is done according to end-applications, and that the figures herein are not limiting as to which LED die are next to each other and in how many quantities.

A first set of LED die represented by 201r include a first semiconductor-containing structure 206r of a first semiconductor height and a first under bump metallization (UBM) 208r of a first UBM height. A second set of LED die 201g each include a second semiconductor-containing structure 206g of a second semiconductor height and a second under bump metallization (UBM) 208r of a second UBM height. A third set of LED die 201b each include a third semiconductor-containing structure 206b of a third semiconductor height and a third under bump metallization (UBM) 208b of a third UBM height. In this embodiment, the first semiconductor-containing structure 206r height is greater than the second semiconductor-containing structure 206g height and the third semiconductor-containing structure 206b height, and the first UBM height is less than the second and third UBM heights.

In one or more embodiments of the LED die 201r, 201g, and 201b, the electrical contacts or UBMs 208r, 208g, 208b are on the respective deposition surfaces (e.g., 116x of FIG. 7 and 116v of FIG. 8), or top surface, of the semiconductor-containing structures 206r, 206g, and 206b. The UBMs 208r, 208g, 208b may comprise any suitable contact known to the skilled artisan analogously to UBMs 108x, 108v, 108z.

In accordance with operation 8.2 of FIG. 5, the UBMs 208g of the green LED die 201g and UBMs 208b of the blue LED die 201b are prepared to compensate for the semiconductor-containing structure 206r of the red LED die 201r being taller than the semiconductor-containing structure 206g of the green LED die 201g and the semiconductor-containing structure 206b of the blue LED die 201b.

The support 202 comprises any suitable support material analogously to support 102.

Turning to FIG. 16 and intermediate structure 200B, at operation 25 of method 10, a reflective material 210 is disposed around sets of the LED die of the intermediate structure 200A. In one or more embodiments, the reflective material 210 is analogous to the reflective material 110 in deposition techniques, materials, and characterization. The reflective material 210 interacts with all surfaces of the LED die 201r, 201g, and 201b except for the surfaces (respective growth surfaces, e.g., 114x of FIG. 7 and 114 v of FIG. 8) that are on the support 202. With respect to the red LED die 201r, a surface of the wirebond pad 207 facing/on the support 202 is protected from the reflective material 210.

Turning to FIG. 17 and intermediate structure 200C, at operation 30 of method 10, the reflective material 210 is planarized or ground to remove a portion thereof from a top surface of the intermediate structure 200B. The reflective material 210 may be removed by any suitable means including, but not limited to chemical mechanical planarization (CMP) and grinding. Upon planarizing, the reflective material 210 yields a reflective coating 211, which may have any suitable thickness. In one or more embodiments, the reflective coating 211 has a thickness in a range of from 40 μm to 60 μm.

In one or more embodiments, the reflective coating 211 serves not only to reflect light, but also serves as a structure element of an array (e.g., 213 of FIG. 18) by holding the LED die 201r, 201g, and 201b of the array together. Thus, in one or more embodiments, the LED die 201r, 201g, and 201b in the light-emitting diode (LED) array 213 are fixed in place by the reflective coating 211.

At operation 35, as illustrated in FIG. 18 by intermediate structure/array 200D, array 213 is removed from the support 202.

With reference to FIG. 19, intermediate structure 250A comprises the array 213, which is flipped and placed in proximity to a device substrate 203, for example a printed circuit board (PCB) or other suitable substrate for inclusion in a final system or device. The device substrate 203 has device contacts 209b, 209g, 209r that correspond to respective UBMs 208b, 208g, 208r. The device contacts 209b, 209g, 209r are in a coplanar configuration relative to each other.

At operation 40, the array 213 of FIG. 19 is attached to the device substrate 203 to prepare LED device 250B of FIG. 20. The device contacts 209b, 209g, 209r and respective UBMs 208b, 208g, 208r are bonded or otherwise soldered. A bonding wire 212 electrically connected to the device substrate 203 is affixed to the wirebond pad 207 of each of the red LED die 201r.

FIG. 28 is a top plan view of array 213 of FIG. 19 prepared according to method 10 of FIG. 1 in conjunction with the specific sub-methods 1A.2 and 1B.2 of FIGS. 3 and 5. As shown in FIG. 28, array 513 includes red LED die 501r including wirebond pad 507, green LED die 501g, and blue LED die 501b, all of the die being held in place by reflective coating material 511.

In one or more embodiments, the LED die 501r, 501g, and 501b are configured to emit different colors, namely red, green, and blue respectively. In embodiments, the die 501r represents a first set of LED die each of a first die height and configured to emit a red color light, the die 501g represents a second set of LED die each of a second die height and configured to emit a green color light; and the die 501b represents a third set of LED die each of a third die height and configured to emit a blue color light. As shown in cross-section of FIGS. 15-20, the plurality of LED die have a coplanar configuration and are spaced apart and retained by the reflective coating. In the embodiment of FIG. 28, the first set of LED die comprise a vertical configuration, and the second and third sets of LED die comprise a flip chip configuration.

FIGS. 21 to 26 illustrate views of LED intermediate structures 300A to 300D during preparation of an LED device 350A or 350B following the process flow illustrated for method 10 of FIG. 1, method 1A.2 of FIG. 3, and method 1B.3 of FIG. 6. FIGS. 21 to 26 are cross-section views of the light emitting device. In FIGS. 21 to 26, phosphor-converted PC-LED semiconductor-containing structures of two of the sets of LED die have differing height as compared to the semiconductor-containing structure of the third set of LED die, in which case an additional operation is needed to compensate UBMs for height differentials. For illustration purposes, a first set of LED die comprise a vertical configuration 301r, and the second and third sets of LED die 301pc1 and 301pc2 are phosphor-converted and comprise a flip chip configuration. In this embodiment, two PC-LED die are illustrated, it is understood that one PC-LED die could be used in conjunction with two LED die (no phosphor conversion) of the same or differing height semiconductor-containing structures.

Assembling the sets of the LED die on a support at operation 20 of FIG. 1 yields intermediate LED structure 300A of FIG. 21. In one or more embodiments, red LED semiconductor-containing structure 306r is obtained at operation 2.2; first phosphor-converted PC-LED semiconductor-containing structure 306pc1 and second phosphor-converted PC-LED semiconductor-containing structure 306pc2 206b are obtained at operation 6.3. The red LED semiconductor-containing structure 306r is processed as-applicable in accordance with FIG. 3. The red LED semiconductor-containing structure 306r is processed as-applicable in accordance with FIG. 3, including compensating for a difference in height of the semiconductor-containing structures compared to PC-LED semiconductor-containing structures 306pc1 and 306pc2. In one or more embodiments, red LED die 301r include: at least one electrical contact, otherwise known as underbump metallizations (UBMs), 308r, a semiconductor-containing structure 306r, and the semiconductor-containing structure 306r further includes wirebond pad 307. In one or more embodiments, first and second PC-LED die 301pc1 and 301pc2 include respectively: at least one, preferably two electrical contacts, otherwise known as underbump metallizations (UBMs), 308pc1, 308pc2; a semiconductor-containing structure 306pc1, 306pc1; a wavelength converting material 322pc1, 322pc2; and optionally further a transparent cover layer 324pc1, 324pc2 on the wavelength converting material 322pc1, 322pc2.

In some embodiments, the wavelength converting material 322pc1, 322pc2 is on an opposing surface of the semiconductor-containing structure 306pc1, 306pc2 from the UBMs 308pc1, 308pc2. The wavelength converting material 322pc1, 322pc2 absorbs energy, converting an entering wavelength to a lower-energy higher wavelength, and scatter light. The wavelength converting material 322pc1, 322pc2 may comprise any suitable material known to the skilled artisan. In one or more embodiments, the wavelength converting material 322pc1, 322pc2 comprises phosphor. As used herein, the term “phosphor” refers to a solid material which emits visible light when exposed to radiation from a deep blue, ultra-violet, or electron beam source. Through careful tuning of the phosphor composition and structure, the spectral content of the emitted light can be tailored to meet certain performance criteria. In some embodiments, the phosphor is selected from a ceramic phosphor plate or phosphor in silicone.

The LED die 301r, 301pc1, and 301pc2 are assembled onto a surface of the support 302 by way of their respective growth surfaces (e.g., 114x of FIG. 7 and 114 v of FIG. 8) at a distance “d” between adjacent semiconductor-containing structures 306r, 306pc1, 306pc2. In one or more embodiments, distance, d, is in a range of from 10 μm to 500 μm. In other embodiments, the LED semiconductor-containing structures 306r, 306pc1, 306pc2 are spaced at least about 120 μm apart from an adjacent LED semiconductor-containing structure. It is understood that an entire assembly of the various LED die 301r, 301pc1, and 301pc2 is done according to end-applications, and that the figures herein are not limiting as to which LED die are next to each other and in how many quantities.

In one or more embodiments of the LED die 301r, 301pc1, and 301pc2, the electrical contacts or UBMs 308r, 308pc1, 308pc2 are on the respective deposition surfaces (e.g., 116x of FIG. 7 and 116v of FIG. 8), or top surface, of the semiconductor-containing structures 306r, 306pc1, and 306pc2. The UBMs 308r, 308pc1, 308pc2 may comprise any suitable contact known to the skilled artisan analogously to UBMs 108x, 108v, 108z.

In accordance with operation 5.2 of FIG. 3, the UBM 308r of the red LED die 301r is prepared to compensate for the semiconductor-containing structure 306r of the red LED die 301r being shorter than the semiconductor-containing structures 306pc1 and 306pc2 of the PC-LED 301pc1 and 301pc2 due to the presence of the wavelength converting material 322pc1, 322pc2 and optional transparent cover layer 324pc1, 324pc2.

The support 302 comprises any suitable support material analogously to support 102.

Turning to FIG. 22 and intermediate structure 300B, at operation 25 of method 10, a reflective material 310 is disposed around sets of the LED die of the intermediate structure 300A. In one or more embodiments, the reflective material 310 is analogous to the reflective material 110 in deposition techniques, materials, and characterization. The reflective material 310 interacts with all surfaces of the LED die 301r, 301pc1, and 301pc2 except for the surfaces (respective growth surfaces, e.g., 114x of FIG. 7 and 114 v of FIG. 8) that are on the support 302. With respect to the red LED die 301r, a surface of the wirebond pad 307 facing/on the support 302 is protected from the reflective material 310.

Turning to FIG. 23 and intermediate structure 200C, at operation 30 of method 10, the reflective material 310 is planarized or ground to remove a portion thereof from a top surface of the intermediate structure 300B. The reflective material 310 may be removed by any suitable means including, but not limited to chemical mechanical planarization (CMP) and grinding. Upon planarizing, the reflective material 310 yields a reflective coating 311, which may have any suitable thickness. In one or more embodiments, the reflective coating 311 has a thickness in a range of from 40 μm to 60 μm.

In one or more embodiments, the reflective coating 311 serves not only to reflect light, but also serves as a structure element of an array (e.g., 313 of FIG. 24 or 25) by holding the LED die 301r, 301pc1, and 301pc2 of the array together. Thus, in one or more embodiments, the LED die 301r, 301pc1, and 301pc2 in the light-emitting diode (LED) array 313 are fixed in place by the reflective coating 311.

At operation 35, as illustrated in FIG. 24 by intermediate structure/array 300D, array 313 is removed from the support 302.

With reference to FIG. 25, intermediate structure 350A comprises the array 313, which is flipped and placed in proximity to a device substrate 303, for example a printed circuit board (PCB) or other suitable substrate for inclusion in a final system or device. The device substrate 303 has device contacts 309pc2, 309pc1, 309r that correspond to respective UBMs 308pc2, 308pc1, 308r. The device contacts 309pc2, 309pc1, 309r are in a coplanar configuration relative to each other.

At operation 40, the array 313 of FIG. 26 is attached to the device substrate 303 to prepare LED device 250B of FIG. 20. The device contacts 309pc2, 309pc1, 309r and respective UBMs 308pc2, 308pc1, 308r are bonded or otherwise soldered. A bonding wire 312 electrically connected to the device substrate 303 is affixed to the wirebond pad 307 of each of the red LED die 201r.

FIG. 29 is a top plan view of array 313 of FIG. 25 prepared according to method 10 of FIG. 1 in conjunction with the specific sub-methods 1A.2 of FIG. 3 and 1B.3 of FIG. 6. As shown in FIG. 29, array 613 includes red LED die 601r including wirebond pad 607, first PC-LED die 601pc1, and second PC-LED die 601pc2, all of the die being held in place by reflective coating material 611.

In one or more embodiments, the LED die 601r, 601pc1, and 601pc2 are configured to emit different colors. In embodiments, the die 601r represents a first set of LED die each of a first die height and configured to emit a first/red light, the die 601pc1 represents a second set of LED die each of a second die height and configured to emit a second/green color light utilizing phosphor conversion; and the die 601pc2 represents a third set of LED die each of a third die height and configured to emit a third/blue color light utilizing phosphor conversion. As shown in cross-section of FIGS. 21-26, the plurality of LED die have a coplanar configuration and are spaced apart and retained by the reflective coating. In the embodiment of FIG. 29, the first set of LED die comprise a vertical configuration, and the second and third sets of LED die comprise a flip chip configuration and phosphor conversion.

FIG. 30 is a top plan view of array prepared according to methods herein, including four types of die. As shown in FIG. 30, array 713 includes red LED die 701r including wirebond pad 707, green LED die 701g, blue LED die 701b, and PC-LED die 701w, all of the die being held in place by reflective coating material 711. In this way, the array and devices including the same include four colors, red, green, blue, and white.

FIG. 31 is a top plan view of array prepared according to methods herein, including four types of die. As shown in FIG. 31, array 813 includes red LED die 801r including wirebond pad 807, green LED die 801g, blue LED die 801b, and yellow die 801y including wirebond pad 807y, all of the die being held in place by reflective coating material 811. In this way, the array and devices including the same include four colors, red, green, blue, and yellow. The yellow die 801y is a vertical configuration analogous to the red die 801r with a different active layer in the semiconductor-containing structure.

In one or more embodiments, accordingly, the plurality of LED die further comprise a fourth set of LED die each of a fourth die height and configured to emit a fourth color light, and maintaining the plurality of LED die having the coplanar configuration and being spaced apart and retained by the reflective coating, wherein the fourth set of LED die comprise either a vertical configuration or a flip chip configuration; and optionally wherein the fourth color light is white or a yellow color.

Applications

In one or more embodiments, a multicolor monolithic light-emitting diode (LED) array of any embodiment herein is attached to a device substrate, optionally wherein the device substrate includes a plurality of device contacts in a coplanar configuration, the device contacts corresponding respectively to the first, second, and third UBMs of the LED array; and a controller configured to control the plurality of pixels individually and/or in sets.

FIG. 32 schematically illustrates an exemplary LED system 900, e.g., a display system, utilizing LED arrays disclosed herein. The display system 900 comprises an LED light emitting array 902 and display 908 in electrical communication with an LED driver 904. The display system 900 also comprises a system controller 906, such as a microprocessor. The controller 906 is coupled to the LED driver 904. The controller 906 may also be coupled to the display 908 and to optional sensor(s) 910, and be powered by power source 912. In one or more embodiments, user data input is provided to system controller 906.

In operation, illumination from some or all of the pixels of the LED array in 902 may be adjusted—deactivated, operated at full intensity, or operated at an intermediate intensity. Beam focus or steering of light emitted by the LED array in 902 can be performed electronically by activating one or more subsets of the pixels, to permit dynamic adjustment of the beam shape without moving optics or changing the focus of the lens in the lighting apparatus.

LED array systems such as described herein may support various other beam steering or other applications that benefit from fine-grained intensity, spatial, and temporal control of light distribution. These applications may include, but are not limited to, precise spatial patterning of emitted light from pixel blocks or individual pixels. Depending on the application, emitted light may be spectrally distinct, adaptive over time, and/or environmentally responsive. The light emitting pixel arrays may provide pre-programmed light distribution in various intensity, spatial, or temporal patterns. Associated optics may be distinct at a pixel, pixel block, or device level. An example light emitting pixel array may include a device having a commonly controlled central block of high intensity pixels with an associated common optic, whereas edge pixels may have individual optics. In addition to flashlights, common applications supported by light emitting pixel arrays include video lighting, automotive headlights, architectural and area illumination, and street lighting.

Other applications of LED devices herein include augmented reality/virtual reality (AR/VR) systems, which may utilize uLEDs disclosed herein. One or more AR/VR systems include: augmented (AR) or virtual reality (VR) headsets, glasses, or projectors. Such AR/VR systems includes an LED light emitting array, an LED driver (or light emitting array controller), a system controller, an AR or VR display, a sensor system 810. Control input may be provided to the sensor system, while power and user data input is provided to the system controller. As will be understood, in some embodiments modules included in the AR/VR system can be compactly arranged in a single structure, or one or more elements can be separately mounted and connected via wireless or wired communication. For example, the light emitting array, AR or VR display, and sensor system can be mounted on a headset or glasses, with the LED driver and/or system controller separately mounted.

In one embodiment, the light emitting array can be used to project light in graphical or object patterns that can support AR/VR systems. In some embodiments, separate light emitting arrays can be used to provide display images, with AR features being provided by a distinct and separate micro-LED array. In some embodiments, a selected group of pixels can be used for displaying content to the user while tracking pixels can be used for providing tracking light used in eye tracking. Content display pixels are designed to emit visible light, with at least some portion of the visible band (approximately 400 nm to 750 nm). In contrast, tracking pixels can emit light in visible band or in the IR band (approximately 750 nm to 2,200 nm), or some combination thereof. As an alternative example, the tracking pixels could operate in the 800 to 1000 nanometer range. In some embodiments, the tracking pixels can emit tracking light during a time period that content pixels are turned off and are not displaying content to the user.

The AR/VR system can incorporate a wide range of optics in the LED light emitting array and/or AR/VR display, for example to couple light emitted by the LED light emitting array into AR/VR display as discussed above. For AR/VR applications, these optics may comprise nanofins and be designed to polarize the light they transmit.

In one embodiment, the light emitting array controller can be used to provide power and real time control for the light emitting array. For example, the light emitting array controller can be able to implement pixel or group pixel level control of amplitude and duty cycle. In some embodiments, the light emitting array controller further includes a frame buffer for holding generated or processed images that can be supplied to the light emitting array. Other supported modules can include digital control interfaces such as Inter-Integrated Circuit (I2C) serial bus, Serial Peripheral Interface (SPI), USB-C, HDMI, Display Port, or other suitable image or control modules that are configured to transmit needed image data, control data or instructions.

In operation, pixels in the images can be used to define response of corresponding light emitting array, with intensity and spatial modulation of LED pixels being based on the image(s). To reduce data rate issues, groups of pixels (e.g. 5×5 blocks) can be controlled as single blocks in some embodiments. In some embodiments, high speed and high data rate operation is supported, with pixel values from successive images able to be loaded as successive frames in an image sequence at a rate between 30 Hz and 100 Hz, with 60 Hz being typical. Pulse width modulation can be used to control each pixel to emit light in a pattern and with an intensity at least partially dependent on the image.

In some embodiments, the sensor system can include external sensors such as cameras, depth sensors, or audio sensors that monitor the environment, and internal sensors such as accelerometers or two or three axis gyroscopes that monitor AR/VR headset position. Other sensors can include but are not limited to air pressure, stress sensors, temperature sensors, or any other suitable sensors needed for local or remote environmental monitoring. In some embodiments, control input can include detected touch or taps, gestural input, or control based on headset or display position. As another example, based on the one or more measurement signals from one or more gyroscope or position sensors that measure translation or rotational movement, an estimated position of AR/VR system relative to an initial position can be determined.

In some embodiments, the system controller uses data from the sensor system to integrate measurement signals received from the accelerometers over time to estimate a velocity vector and integrate the velocity vector over time to determine an estimated position of a reference point for the AR/VR system. In other embodiments, the reference point used to describe the position of the AR/VR system can be based on depth sensor, camera positioning views, or optical field flow.

Based on changes in position, orientation, or movement of the AR/VR system, the system controller can send images or instructions the light emitting array controller. Changes or modification in the images or instructions can also be made by user data input, or automated data input as needed. User data input can include but is not limited to that provided by audio instructions, haptic feedback, eye or pupil positioning, or connected keyboard, mouse, or game controller.

EMBODIMENTS

Various embodiments are listed below. It will be understood that the embodiments listed below may be combined with all aspects and other embodiments in accordance with the scope of the invention.

Embodiment (a). A multicolor monolithic light-emitting diode (LED) array comprising: multicolor pixels comprising a plurality of light emitting diode (LED) die including: a first set of LED die each of a first die height and configured to emit a first color light; a second set of LED die each of a second die height and configured to emit a second color light; a third set of LED die each of a third die height and configured to emit a third color light; and the first die height being substantially equal to the second die height and the third die height; and the plurality of LED die having a coplanar configuration and being spaced apart and retained by a reflective coating.

Embodiment (b). The LED array of embodiment (a), wherein the first set of LED die comprise a vertical configuration, and the second set of LED die comprise a flip chip configuration, and the third set of LED die comprise either a vertical configuration or a flip chip configuration.

Embodiment (c). The LED array of embodiment (a) or (b), wherein the vertical configuration includes a silicon substrate and the flip chip configuration includes a sapphire substrate.

Embodiment (d). The LED array of any one of embodiments (a) to (c), wherein the first set of LED die comprise a vertical thin film (VTF) configuration, and the second set of LED die comprise a thin film flip chip configuration (TFFC), and the third set of LED die comprise either a VTF configuration or a TFFC configuration.

Embodiment (e). The LED array of any one of embodiments (a) to (d), wherein one or more of the first, second, and third sets of LED die further comprises a wavelength converting material, and optionally, wherein the wavelength converting material comprises a ceramic phosphor plate or a phosphor in silicone, and optionally wherein the wavelength converting material further comprises a transparent cover layer.

Embodiment (f). The LED array of any one of embodiments (a) to (e), wherein the first set of LED die comprise a phosphide light emitting layer, and the second and third sets of LED die comprise a nitride light emitting layer, optionally wherein the phosphide light emitting layer comprises AlInGaP, and the nitride light emitting layer comprises GaN or InGaN.

Embodiment (g). The LED array of any one of embodiments (a) to (f), wherein the first set of LED die each further comprise a bonding wire affixed to a wirebond pad of the first LED die while maintaining the coplanar configuration among the first, second, and third sets of LED die, and optionally the first set of LED die each further comprise a current spreading layer electrically coupled to the wirebond pad.