WO2023158550A1

WO2023158550A1 - Quantum dot color conversion devices

Info

Publication number: WO2023158550A1
Application number: PCT/US2023/011917
Authority: WO
Inventors: Mark Alejandro Quesada
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 2022-02-18
Filing date: 2023-01-31
Publication date: 2023-08-24
Anticipated expiration: 2024-08-18
Also published as: TW202410384A

Abstract

Apparatuses and methods are described for substrate materials and designs that provide reduced heat within color converter devices. In some examples, a color converter plate includes a first glass substrate and a second glass substrate opposite the first glass substrate. The color converter plate also includes a metal material disposed between the first glass substrate and the second glass substrate. The metal material may be aluminum foil, for example, and includes a plurality of cavities for holding color converting material, such as a solution of quantum dots. In some examples, binary diffractive optical elements are deposited along a surface of the first glass substrate. In some examples, a surface of the second glass substrate is coated with a low emissivity material. The color converter device may be packaged with light-emitting diode (LED) arrays within LED displays, for example.

Description

U.S. Non-Provisional Application for

QUANTUM DOT COLOR CONVERSION DEVICES

Inventor:

Mark Alejandro Quesada

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Serial No. 63/311574 filed on February 18, 2022, the content of which is relied upon and incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

[0002] The present disclosure relates to the production of color converter devices and, more particularly, to substrate materials and designs for color converters of lightemitting diode devices.

BACKGROUND

[0003] Light-emitting diodes (LEDs), such as micro-LEDs, mini -LEDs, and organic light-emitting diodes (OLEDs), are used in a variety of applications. For example, they may be used in glass display panels such as in mobile devices, laptops, tablets, computer monitors, automotive display, smartwatch, backlights, signage, and television displays. These LEDs can be integrated with color conversion elements such as quantum dots color converters (e.g., quantum dots color filters) to emit light of various colors, such as red light and green light. For instance, the LEDs may emit blue light, which excites red and green quantum dots to emit red and green light, respectively.

[0004] For instance, FIG. 2 illustrates a prior art LED device 200 that includes a quantum dot (QD) color converter plate 202 integrated with a Complementary Metal- Oxide-Silicon (CMOS) backplane 204. The CMOS backplane 204, which includes a first passivation layer 217, a second passivation layer 219, and a plurality of CMOS pixels 222, can drive blue micro-LED arrays 206. QD color converter plate 202 includes a single glass substrate 208 as well as a photo lithographically patterned black matrix polymer layer 210 between red and green QD photo resists 212. QD color converter plate 202 can be flip bonded to the blue micro-LED arrays 206, as illustrated by flip chip bumps 214.

[0005] The black matrix polymer layer 210 divides the red, green, and blue pixels of the LED device 200 and can block light leaking from areas between the pixels. For example, black matrix polymer layer 210 is typically prepared with metal oxide, carbon black, titanium black or organic pigment dispersed in a photoresist polymer, which have relatively higher light absorption properties. The black matrix polymer layer 210, however, negatively impacts the overall optical efficiency of the LED device 200 by absorbing incident blue LED photons from blue micro-LED arrays 206.

[0006] During operation, these LED devices generate heat. LEDs, however, are temperature sensitive. For example, absorbed heat may cause LEDs to be less efficient, or may even cause color shifts in the emitted light. To dissipate component generated heat, some device designs include substrates that absorb and direct heat away from the LEDs. These substrates include uniform sheets of glass and printed circuit board (PCB) layered structures. The heat may be directed to a heat sink, for example. In some examples, the color conversion elements are placed at far distances away from LED surfaces. These designs, however, may have drawbacks. For example, they may not direct enough heat away from color conversion elements thereby causing the above noted inefficiencies or shifts in emitted light, and may, in some instances, increase device thickness. Moreover, thermal considerations can limit the display brightness level, which is a key value metric for displays, such as micro-LED displays.

SUMMARY

[0007] The embodiments disclosed herein are directed to apparatus and methods of laser sealed hermetic glass packages containing color converting elements with metal reflective walls, and that may reduce heat within color converters, such as quantum dots (QD) color converters (e.g., quantum dots color filters). For example, the apparatuses and methods described herein may employ a color converter hermetic glass structure that includes a metal portion filled with quantum dot materials, as well as top and bottom glass substrates positioned on either side of the metal portion, to provide thermal radiation properties designed to keep the internal color-converting quantum dots materials at lower operating temperatures. Optical elements, such as binary diffractive optical elements (DOEs) (e.g., thermally radiative photonic structures), optical metasurface elements, and silicon carbide (SiC) based optical elements (e.g., thermally radiative SiC photonic structures), may be deposited along the top glass substrate. The optical elements may operate by means of interference and diffraction to produce arbitrary distributions of light. In some examples, the bottom glass substrate may be coated with low emissivity material (e.g., a “low-E” coating) to reflect thermal radiation emanating from LED arrays. The low emissivity material may have a thermal emissivity of between .02 and .05, inclusive, in some examples.

[0008] Among other advantages, the embodiments may provide QD color converter plates that provide a reliable hermetic environment for quantum dot operation with highly reflective (and, e.g., poorly light absorbing) walls for more efficient and longer lived operation over conventional structures. For example, the embodiments promote more efficient color conversion by recycling reflected light (e.g., light in visible wavelengths) from pore walls, and provide a hermetic glass environment that accommodates color converting materials, including quantum dots. The hermetic glass environment may further provide superior water vapor transmission rates (WVTRs) over conventional structures. Those of ordinary skill in the art having the benefit of these disclosures may recognize other benefits as well.

[0009] In some examples, a color converter plate includes a first glass substrate and a second glass substrate opposite the first glass substrate. The color converter plate also includes a metal material disposed between the first glass substrate and the second glass substrate. The metal material may be aluminum foil, for example, and includes a plurality of cavities. The plurality of cavities may hold color converting material, such as a solution of quantum dots. In some examples, binary diffractive optical elements are deposited along a surface of the first glass substrate. In some examples, a surface of the second glass substrate is coated with a low emissivity material. The color converter device may be packaged with light-emitting diode arrays within LED displays, for example.

[0010] In some embodiments, a device may comprise a first glass substrate and a second glass substrate opposite the first glass substrate. The device may further comprise a metal material disposed between the first glass substrate and the second glass substrate. The metal material comprises a plurality of cavities. The plurality of cavities may hold color converting material. In some examples, the plurality of cavities include the color converting material. In some examples, the color converting material comprises quantum dots. In some examples, the metal material comprises aluminum foil.

[0011] In some examples, binary diffractive optical elements are deposited along a first surface (e.g., first side) of the first glass substrate. In some examples, a first surface of the second glass substrate is coated with a low emissivity material. In some examples, a second surface e.g., second side) of the first glass substrate is welded to a first surface of the metal material. The second surface of the first glass substrate is opposite the first surface of the first glass substrate. In some examples, a second surface of the second glass substrate is welded to a second surface of the metal material. The second surface of the second glass substrate is opposite the first surface of the second glass substrate.

[0012] In some embodiments, an LED device comprises a color converter plate. The color converter plate may comprise a first glass substrate and a second glass substrate opposite the first glass substrate. The color converter plate may further comprise a metal material disposed between the first glass substrate and the second glass substrate. The metal material comprises a plurality of cavities. The plurality of cavities may hold color converting material. The LED device may further include a plurality of LED arrays disposed between the metal material and the second glass substrate. In some examples, the plurality of cavities include the color converting material. In some examples, the color converting material comprises quantum dots material. In some examples, the metal material comprises aluminum foil.

[0013] In some examples, binary diffractive optical elements are deposited along a first surface of the first glass substrate. In some examples, a first surface of the second glass substrate is coated with a low emissivity material. In some examples, a second surface of the first glass substrate is welded to a first surface of the metal material. In some examples, a second surface of the second glass substrate is welded to a second surface of the metal material.

[0014] In some examples, a method, such as by one or more processors executing instructions, includes disposing a metal material on a first glass substrate. The metal material may comprise a plurality of cavities. The method may also include filling the plurality of cavities with the color converting material. The method may further include disposing a second glass substrate on the metal material. In some examples, the color converting material comprises quantum dots material. In some examples, the metal material comprises aluminum foil. [0015] In some examples, the method includes depositing binary diffractive optical elements along a first surface of the first glass substrate. In some examples, the method includes coating a first surface of the second glass substrate with a low emissivity material. In some examples, the method includes welding a second surface of the first glass substrate to the first surface of the metal material. In some examples, the method includes welding a second surface of the second glass substrate to the second surface of the metal material.

[0016] In some embodiments, a non-transitory computer readable medium stores instructions that, when executed by one or more processors, cause the one or more processors to perform a method that includes disposing a metal material on a first glass substrate. The metal material may comprise a plurality of cavities. The method may also include filling the plurality of cavities with the color converting material. The method may further include disposing a second glass substrate on the metal material. In some examples, the color converting material comprises quantum dots material. In some examples, the metal material comprises aluminum foil.

[0017] In some examples, the method includes depositing binary diffractive optical elements along a first surface of the first glass substrate. In some examples, the method includes coating a first surface of the second glass substrate with a low emissivity material. In some examples, the method includes welding a second surface of the first glass substrate to the first surface of the metal material. In some examples, the method includes welding a second surface of the second glass substrate to the second surface of the metal material.

BRIEF DESCRIPTION OF DRAWINGS

[0018] The above summary and the below detailed description of illustrative embodiments may be read in conjunction with the appended Figures. The Figures show some of the illustrative embodiments discussed herein. As further explained below, the claims are not limited to the illustrative embodiments. For clarity and ease of reading, Figures may omit views of certain features.

[0019] FIG. 1 illustrates a device in accordance with some examples.

[0020] FIG. 2 illustrates a prior art device.

[0021] FIGS. 3A, 3B, and 3C illustrate the assembly of a device in accordance with some examples. [0022] FIG. 4A illustrates the assembly of a device in accordance with some examples.

[0023] FIGS. 4B and 4C illustrate observed properties of the device of FIG. 4A in accordance with some examples.

[0024] FIGS. 5 and 6 illustrate exemplary methods for generating devices with substrate structures in accordance with some examples.

[0025] FIG. 7 illustrates a system to assemble a device in accordance with some examples.

[0026] FIGS. 8 A and 8B illustrate the assembly of a device in accordance with some examples.

[0027] FIGS. 9 A, 9B, and 9C illustrate further assembly of the device of FIGS. 8 A and 8B in accordance with some examples.

[0028] FIGS. 10A, 10B, 10C, and 10D illustrate further assembly of the device of FIGS. 9A, 9B, and 9C in accordance with some examples.

[0029] FIGS. 11 A, 1 IB, and 11C illustrate an LED device in accordance with some examples.

[0030] FIG. 12 illustrates a display in accordance with some examples.

DETAILED DESCRIPTION

[0031] The present application discloses illustrative (i.e., example) embodiments. The disclosure is not limited to the illustrative embodiments. Therefore, many implementations of the claims will be different than the illustrative embodiments. Various modifications can be made to the claims without departing from the spirit and scope of the disclosure. The claims are intended to cover implementations with such modifications.

[0032] At times, the present application uses directional terms (e.g. , front, back, top, bottom, left, right, etc.) to give the reader context when viewing the Figures. The claims, however, are not limited to the orientations shown in the Figures. Any absolute term (e.g., high, low, etc.) can be understood as disclosing a corresponding relative term (e.g., higher, lower, etc.). Moreover, although the exemplary examples discussed herein may include LED devices, the exemplary embodiments may include any type of semiconductor or emission material device. [0033] FIG. 1 illustrates a color converter plate 100 that includes a metal material 102 disposed between a first (e.g., top) glass substrate 104 and a second (e.g., bottom) glass substrate 106. The metal material 102 provides highly reflective surfaces over a broad spectral range, such as over visible wavelengths. For example, the metal material 102 may include aluminum foil. In some examples, the metal material 102 may include chromium. The highly reflective surfaces may allow for more efficient conversion of incident blue photons compared to conventional color converters.

[0034] Each of the first glass substrate 104 and the second glass substrate 106 may be welded (e.g., laser welded) to a surface of the metal material 102. For example, first glass substrate 104 may be welded to the metal material 102 along portions of a first interface 110. Second glass substrate 106 may be welded to the metal material 102 along portions of a second interface 112. As such, the metal material 102 may server as a framework onto which first glass substrate 104 and second glass substrate 106 may be attached.

[0035] Metal material 102 may include cavities 120 (e.g., “pores”) to hold a solution 130 that includes color conversion elements 132. In some examples, the cavities 120 are concave extending towards the second glass substrate 106. Additionally, the cavities 120 may be patterned along metal material 102. The pattern may match a pattern of LEDs, such as a pitch of LED arrays (e.g., pLED arrays), below the second glass substrate 106. The color conversion material 130 may include, for example, fluorophores (e.g., pi-orbital organic molecules with singlet or triplet transitions, phosphors (e.g., transition metal elements exhibiting transitions epitomized by ligand field theoretical descriptions, inorganic compounds exhibiting band structures (e.g., chalcogenides), or nano-phosphors (e.g., QDs or perovskites). For instance, the color conversion material 130 may be a solution that includes QDs (e.g., core-type QDs, core-shell QDs, alloyed QDs). In some examples, the cores of the QDs are made of cadmium selenide (CdSe), cadmium telluride (CdTe), indium phosphide (InP), or zinc selenide (ZnSe), among other examples. The cavities 120 can maintain the isolation of RGB pixels, thereby reducing pixel-to-pixel crosstalk, with sidewalls 140 reflecting back emissions from the color conversion elements 132. As a result, usable photons that otherwise may be lost to black matrix-type absorption are preserved (e.g., the number of lost usable photons are decreased). The cavities 120 may act as highly reflective hermetic volumes, and may be filled with a QD solution 130 within a nitrogen glove box to minimize trapped oxygen or moisture. [0036] In some examples, the metal material 102 may include aluminum foil that has a cavity 120 density between 1800 cavity/cm³ and 2200 (e.g., 2000 cavity/cm³ density), a cavity 120 diameter between 15 pm and 25 pm (e.g., 20 pm diameter cavity pattern), and a thickness between 10 pm and 20 pm (e.g., 15 pm thickness). The cavities 120 may be of any suitable shape to hold the solution 130.

[0037] In some examples, and as further described herein, binary diffractive optical elements (DOEs) may be deposited along a top surface 150 of the first glass substrate 104. The binary DOEs may include, for example, a silicon carbide (SiC) thermally radiative binary material (e.g., thermally radiative SiC photonic structures). The binary DOEs may diffract surface thermal photons laterally away from the top surface 150 of the first glass substrate 104.

[0038] Further, a bottom surface 152 of second glass substrate 106 may be coated with a low emissivity material (e.g., “low-E” coating), thereby reflecting infrared photons emanating from LED arrays. In some examples, the bottom surface 152 of the second glass substrate is attached to one or more LEDS, such as pLED arrays. The pattern of the plurality of cavities 120 may match a pattern of the LEDs along the bottom surface 152 of second glass substrate 106.

[0039] FIGS. 3A, 3B, and 3C illustrate the assembly of a color converter plate 300. For example, and with reference to FIG. 3 A, a bottom glass substrate 302 is positioned to receive a metal material 310 along a first surface 304. The bottom glass substrate 302 may be plain glass, and may include a low emissivity coating at least along a second surface 306 opposite the first surface 304 to reflect thermal radiation. In some examples, the bottom glass substrate 302 includes a low emissivity coating along each of the first surface 304 and the second surface 306. Further, the metal material 310 may include a plurality of cavities 320 to hold a color conversion solution as described herein. The metal material 310 may include, for example, aluminum foil.

[0040] The bottom glass substrate 302 may be attached to the metal material 310 by welding. For example, a laser, such as a 355 nm, ~10 ns pulse width, 100 pm diameter focal spot laser, may be used to weld first surface 304 of the bottom glass substrate 302 to a first surface 312 of the metal material 310. The focal spot laser may be configured to provide the laser using a ~50 mm/sec sweep rate. In some examples, the first surface 304 of the bottom glass substrate 302 is welded to the first surface 312 of the metal material 310 along a first interface perimeter 322, which can provide strong glass-metal seals suitable for long lived hermetic operation. In some examples, additional welds may be provided by sweeping the laser along any of one or more gap regions between adjacent cavities 120 to confer enhanced strength and ensure a more robust hermetic package.

[0041] FIG. 3B illustrates the filling of cavities 320 with a solution 330 that includes color conversion elements 332. The color conversion elements 332 may include quantum dots, such as red and green quantum dots. The solution 330 may be poured onto a second surface 340 of the metal material 310, where the second surface 340 includes the plurality of cavities 320. In this example, a squeegee 350 is used to spread the solution 330 over the plurality of cavities 320. In some examples, a spin coater is used to apply (e.g., spray) the solution 330 onto the second surface 340 of the metal material 310 thereby filling the plurality of cavities 320.

[0042] FIG. 3C illustrates a top glass substrate 360 being attached to metal material 310. The top glass substrate 360 may be positioned over the second surface 340 of the metal material 310, and may be attached to the second surface 340 by welding. For example, the above mentioned laser may be used to weld a first surface 362 of the top glass substrate 360 to the second surface 340 of the metal material 310. In some examples, the first surface 362 of the top glass substrate 360 is welded to the second surface 340 of the metal material 310 along a second interface perimeter 364, which can provide strong glass-metal seals suitable for long lived hermetic operation. As noted above, additional welds may be provided by sweeping the laser along any of one or more gap regions between adjacent cavities 120 to confer enhanced strength and ensure a more robust hermetic package.

[0043] In some examples, the laser is communicatively coupled to a controller that configures and controls the laser to perform the welding. The controller may include one or more processors that execute instructions to configure and control the laser to perform the welding. For example, the one or more processors may execute the instructions to issue commands to the laser to cause the laser to weld the bottom glass substrate 302 to the metal material 310, and to weld the top glass substrate 360 to the metal material 310, as described herein.

[0044] FIG. 4A illustrates a color converter plate 400 that includes a metal material 402 disposed between a first (e.g., top) glass substrate 404 and a second (e.g., bottom) glass substrate 406. The metal material 402 provides highly reflective surfaces over a broad spectral range, such as over visible wavelengths. For example, the metal material 402 may include aluminum foil. In some examples, the metal material 402 may include chromium. The highly reflective surfaces may allow for more efficient conversion of incident blue photons compared to conventional color converters. Metal material 402 may include cavities 420 to hold a solution 430 that includes color conversion elements 432, such as red and green quantum dots.

[0045] Each of the first glass substrate 404 and the second glass substrate 406 may be welded (e.g., laser welded) to a surface of the metal material 402. For example, first glass substrate 404 may be welded to the metal material along portions of a first interface 410. Second glass substrate 406 may be welded to the metal material along portions of a second interface 412. As such, the metal material 402 may server as a framework onto which first glass substrate 404 and second glass substrate 406 may be attached.

[0046] In some examples, binary diffractive optical elements (DOEs) 454 may be deposited along a top surface 450 of the first glass substrate 404. The binary diffractive optical elements (DOEs) 454 may include silicon carbide (SiC) thermally radiative binary material e.g., thermally radiative SiC photonic structures), for example. The binary DOEs 454 may, in some examples, have a pitch of 6.1 pm and a height of 1 pm. The binary DOEs 454 may diffract surface thermal photons laterally away from the top surface 450 of the first glass substrate 404, as indicated by arrows 455.

[0047] For example, FIG. 4B illustrates a graph 480 with temperature along a first axis 482 and wavelength along a second axis 484. The surface thermal photon wavelengths associated with LED surface temperatures may be predicted using Wien’s Law, and is indicated in the graph 480 by line 486. For LED surface temperatures in the range from room temperature (RT) to 150° C, the commensurate wavelengths range from 7 pm - 10 pm, as indicated by area 488 of graph 480.

[0048] In the example of FIG. 4A, the binary DOEs 454 are equidistant from each other. In other examples, the binary DOEs 454 are in a checkerboard pattern, such that at least one portion of each binary DOE 454 is in contact with portions of three other binary DOEs 454.

[0049] Further, a bottom surface 452 of second glass substrate 406 may be coated with a low emissivity material, thereby reflecting infrared photons emanating from LED arrays. In some examples, the bottom surface 452 of the second glass substrate is attached to one or more LEDS, such as pLED arrays. The pattern of the plurality of cavities 420 may match a pattern of the LEDs, for example.

[0050] FIG. 4C illustrates a graph 490 with wavelength on a first axis 492 and transmission spectra along a second axis 494. Line 496 indicates an emissivity “transmission” spectra of a 6.1 pm SiC checkerboard pattern illustrating the thermal wavelengths that will transmit - via coupling - into the diffraction orders and space above the first glass substrate 404 of FIG. 4A. This thermal transmission depletes the surface of thermal phonons, in effect cooling the surface, forming a thermal gradient for heat flow from the substrate interior to the surface. The spectra was computed using Kirchhoff s law as 1 - Pref , where P_ref is the sum of reflection coefficients of all the propagating diffraction orders of the system. If absorption is negligible, 1 - Pref ~ Brans. Eleven orders were found adequate for calculations to converge to the general transmission curve features shown. As illustrated, both visible light, as indicated by area 497, and thermal infrared phonons, as indicated by area 499, transmit - or couple - into the outgoing diffraction orders, with an effective stopband from ~ 900 nm to 6000 nm. This feature is beneficial in passing both visible photons associated with the quantum dots and LED materials along with thermal photon heat into the space above the color converting plate (e.g., color converter plate 400).

[0051] FIG. 5 illustrates an exemplary method 500 to form a color converter plate, such as the color converter plate 100 of FIG. 1. Beginning at step 502, a metal material, such as aluminum foil, is disposed on a first glass substrate. The metal material comprises a plurality of cavities for holding color converting material. For example, metal material 102 comprising cavities 120 may be disposed on second glass substrate 106. At step 504, the plurality of cavities are filled with the color converting material. For example, the cavities 120 may be filled with solution 130 that includes color conversion elements 132. The color conversion elements 132 may include red and green quantum dots, for example. Further, and at step 506, a second glass substrate is disposed on the metal material. For example, first glass substrate 104 may be disposed on metal material 102. In some examples, each of the first glass substrate and the second glass substrate are welded to the metal material. For example, the first glass substrate may be welded to a first surface of the metal material along portions of a first interface perimeter, and the second glass substrate may be welded to a second surface opposite the first surface of the metal material along portions of a second interface perimeter. The method then ends.

[0052] FIG. 6 illustrates an exemplary method 600 to form a color converter plate, such as the color converter plate 400 of FIG. 4. Beginning at step 602, a first surface of an aluminum foil is welded to a first surface of a first glass substrate. The aluminum foil includes a second surface with a plurality of cavities. For example, bottom glass substrate 402 may be laser welded to the first surface 412 of the metal material 410. At step 604, the plurality of cavities are filled with a quantum dot material. For example, the plurality of cavities may be filled with the solution 430 that includes color conversion elements 432. The color conversion elements 432 may include red and green quantum dots, for example.

[0053] Proceeding to step 606, the second surface of the aluminum foil is welded to a first surface of a second glass substrate. For example, top glass substrate 460 may be laser welded to the second surface 440 of the metal material 410. At step 608, a plurality of binary diffractive optical elements are disposed on a second surface of the first glass substrate. For example, binary DOEs 454 may be deposited along a top surface 450 of the first glass substrate 404. Further, and at step 610, a second surface of the second glass substrate is coated with a low emissivity material. For example, a bottom surface 452 of second glass substrate 406 may be coated with a low emissivity material.

[0054] In some examples, the plurality of binary diffractive optical elements are disposed on the second surface of the first glass substrate before the first glass substrate is welded to the metal material. In some examples, the plurality of binary diffractive optical elements are disposed on the second surface of the first glass substrate after the first glass substrate is welded to the metal material. In some examples, the second surface of the second glass substrate is coated with the low emissivity material before the second glass substrate is welded to the metal material. In some examples, the second surface of the second glass substrate is coated with the low emissivity material after the second glass substrate is welded to the metal material. The method then ends.

[0055] FIG. 7 illustrates an exemplary system 700 to assemble a color converter plate, such as the color converter plate 100 of FIG. 1. The system 700 a controller 701, a laser system 720, a spin coater 730, and a color converter plate, such as the color converter plate 100 of FIG. 1. The controller 701 includes one or more processors 702, a memory 704, and in some examples, a transceiver 706. The one or more processors 702 may include, for example, one or more central processing units (CPUs), microcontrollers, general processing units (GPUs), or any other processing devices. The memory 704 may include instructions that can be accessed and executed by the one or more processors 702. For example, memory 704 may be a non-transitory computer readable medium storing the instructions, such as an EPROM, an EEPROM, or any other suitable memory. Transceiver 706 may provide for communications over a wired or wireless network. For example, the transceiver may transmit data to, and receive data from, each of the laser system 720 and the spin coater 730. [0056] Controller 701 may transmit commands to laser system 720 to weld a first glass substrate to a metal material. For example, controller 701 may transmit commands to laser system 720 to weld second glass substrate 106 to metal material 102 along portions of the second interface 112.

[0057] Controller 701 may transmit commands to spin coater 730 to disperse a solution onto the metal material to fill the plurality of cavities. For example, controller 701 may transmit commands to spin coater 730 to have solution 130, which may include color conversion elements 132, dispersed onto metal material 102 to fill cavities 120. Controller 701 may transmit commands to the spin coater 730 to start, and to stop, the application of the solution.

[0058] Further, controller 701 may transmit additional commands to laser system 720 to weld a second glass substrate to the metal material. For example, controller 701 may transmit commands to laser system 720 to weld first glass substrate 104 to metal material 102 along portions of the first interface 110.

[0059] In some examples, controller 701 transmits additional commands to laser system 720 to sweep the laser along any of one or more gap regions between adjacent cavities 120 to confer enhanced strength and ensure a more robust hermetic package.

[0060] FIGS. 8 A and 8B illustrate the assembly of a color converter plate 800, which includes performing photolithographic processes on a glass substrate 802 using a hole-patterned mask 804 that has a plurality of holes 806. In some examples, the plurality of holes 807, such as 1 mm radii holes, may be distributed in a pattern. For example, the holes 807 may be distributed in a pattern that includes a predetermined number of holes (e.g., dots) per inch, such as 10 holes per inch (e.g., 10 dpi). The hole-patterned mask 804 may also include a rim 808 of a particular width. For example, the rim 808 may have a width in the range of 2 mm to 10 mm, such as 5 mm. In some examples, the glass substrate 802 is square-shaped with sides anywhere between 50 mm and 150 mm, such as with sides of 100 mm. In some examples, the mask 806 is a metal, such as aluminum, and is laser bonded to the glass substrate 802.

[0061] Further, photolithography is performed on the glass substrate 802 to apply a metal, such as chromium (Cr), throughout the hole-patterned mask 804 to form a metal layer 820. For example, chromium may be applied to the hole-patterned mask 804 using any suitable photolithography process, which results in a chromium layer 820 over portions of the glass substrate 802. Once the metal layer 820 is formed, an electroplating process is applied to the metal layer 820 to expand the metal layer 820 to a predetermined height 822. For example, any suitable electroplating process may be applied to the chromium layer 820 that results from the photolithography process to expand the chromium layer 820 to a height 822 of between 2 pm and 25 pm, such as 20 pm. In some examples, a rim along the periphery of color converter plate 800 may be added by masking the interior and sputtering additional metal, serving both as a platform to bond a top glass plate, as well as a frame with which to center the hole-patterned mask 804. In some examples, LED arrays may provide light from a backside 812 of color converter plate 800.

[0062] FIGS. 9A, 9B, and 9C illustrate further assembly of the color converter plate 800 to assemble a photoresist-filled color converter plate 900. For example, a photoresist mask 902 that includes a plurality of holes 906 and a plurality of blocked holes 904 is positioned on the hole-patterned mask 804. The photoresist mask 902 may be aluminum, for example, and may be positioned on the hole-patterned mask 804 with wetting. The wetting may ensure blockage of the blocked holes 904. In some examples, the dimensions of the photoresist mask 902 are similar to, or the same as, the dimensions of the hole- patterned mask 804. For example, each of the photoresist mask 902 and the hole- patterned mask 804 may be square-shaped and have sides of 100 mm.

[0063] The plurality of holes 906 may allow for passage of a solution, such as a photoresist, and the plurality of blocked holes 904 may block passage of the solution. For example, a solution 930 that includes color conversion elements 932 may be poured (e.g., from a container) onto a top surface of the photoresist mask 902, where the plurality of holes 906 allow passage of the solution 930 to the metal layer 820, while the plurality of blocked holes 904 block passage of the solution 930 to the metal layer 820. In some examples, the color conversion elements 932 are red quantum dots. In this example, a squeegee 350 is used to spread the solution 930 over the top surface of the photoresist mask 902. In some examples, a spin coater (e.g., spin coater 730) is used to apply (e.g., spray) the solution 930 onto the top surface of the photoresist mask 902. As a result, only a portion of the plurality of holes 806 of the hole-patterned mask 804 are filled with the solution 930.

[0064] In some examples, the above process may be repeated using a photoresist mask 902 with a differing pattern of the plurality of holes 906 and plurality of blocked holes 904 thereby allowing additional solution 930 to pass through to a different portion of the plurality of holes 806 of the hole-patterned mask 804. For example, a first solution 930 that includes red quantum dots, but not any other color quantum dots, may be applied to a first photoresist mask 902 with a first pattern of the plurality of holes 906 and plurality of blocked holes 904, thereby filling a first portion of the plurality of holes 806 of the hole-patterned mask 804. The first photoresist mask 902 may then be removed and replaced with a second photoresist mask 902 that includes a second pattern of the plurality of holes 906 and plurality of blocked holes 904. A second solution 930 that includes blue quantum dots, but not any other color quantum dots, may be applied to the second photoresist mask 902 thereby filling a second portion of the plurality of holes 806 of the hole-patterned mask 804. The second photoresist mask 902 may then be removed and replaced with a third photoresist mask 902 that includes a third pattern of the plurality of holes 906 and plurality of blocked holes 904. A third solution 930 that includes green quantum dots, but not any other color quantum dots, may be applied to the third photoresist mask 902 thereby filling a third portion of the plurality of holes 806 of the hole-patterned mask 804. In some examples, each of the first, second, and third photoresist masks 902 include a plurality of holes 906 within alternating rows (e.g., each photoresist mask 902 may include a plurality of holes 806 within every third row, where the rows with the a plurality of holes 906 alternate between the first, second, and third masks 902). FIG. 9C illustrates the resulting photoresist-filled color converter plate 900.

[0065] FIGS. 10 A, 10B, 10C, and 10D illustrate further assembly of the photoresist- filled color converter plate 900 to assemble a sealed color converter plate 1000. FIG. 10A illustrates the photoresist-filled color converter plate 900. FIG. 10B illustrates a top glass substrate 1002 that may be placed over the photoresist-filled color converter plate 900. The photoresist-filled color converter plate 900 includes a bottom glass substrate 1003 (e.g., the glass substrate 802) and the metal layer 820. In some examples, the top glass substrate 1002 has similar, or the same, dimensions as the photoresist-filled color converter plate 900. For example, each of the photoresist-filled color converter plate 900 and the top glass substrate 1002 may be square-shaped with sides approximately 10 mm in length.

[0066] FIG. 10C illustrates the sealing of the top glass substrate 1002 to the photoresist-filled color converter plate 900 using a laser beam 1004 provided by a laser system, such as laser system 720 (laser system not shown in FIG. 10C). For example, the top glass substrate 1002 and the photoresist-filled color converter plate 900 may be placed in a nitrogen glove box (e.g., to prevent oxygen and moisture from entering the assembly), and may be hermetically sealed by providing the laser beam 1004 along portions of a perimeter 1008 of the top glass substrate 1002 and the metal layer 820 (e.g., chromium layer 820) portion of the photoresist-filled color converter plate 900. In some examples, the laser beam 1004 is applied along all portions of the perimeter 1008. FIG. 10D illustrates the resulting sealed color converter plate 1000.

[0067] FIGS. 11 A, 1 IB, and 11C illustrate an LED device 1100 that includes a top glass substrate 1102, a metal material 1104, an LED array 1106, and a backplane layer 1108. In some examples, the backplane layer 1108 may be a complementary metal-oxide semiconductor (CMOS) based backplane layer. The metal material 1104 may be made of one or more metal layers including a layer of aluminum, and may include a plurality of cavities 1103 for holding color converting material as described herein. For example, the cavities 1103 may hold green quantum dots 1120, blue quantum dots 1122, and red quantum dots 1124. The LED array 1106 may be a pLED array, for example, and may disposed between the metal layer 1106 and a bottom glass substrate 1140. The metal layer 1104 may be deposited within a cavity 1150 of the top glass substrate 1102. Further, LED device 1100 may include metal leads 1130 (e.g., metal traces) to allow, for example, for a power connection. As illustrated in FIG. 11 A, the cavities 1103 are patterned to have a pitch 1125 that matches a pitch 1107 of LED array 1106.

[0068] FIG. 11B illustrates a rim 1132 along which the top glass substrate 1102 may be laser welded to the metal material 1104. FIG. 11B also illustrates that metal material 1104 may be made of several layers, including a first material layer 1134, a second material layer 1135, a third material layer 1136, and a fourth material layer 1137. For example, first material layer 1134 may be made of aluminum and have a depth in the range from 2 pm to 3 pm (e.g., 2.1 pm), inclusive. The second material layer 1135 may be made of Chromium and have a depth in the range from 18 pm to 25 pm (e.g., 20 pm), inclusive. The third material layer 1136 may be made of aluminum oxide (AI2O3) and have a depth in the range from 175 pm to 250 pm (e.g., 200 pm), inclusive. The fourth material layer 1137 may also be made of aluminum and have a depth in the range from 175 pm to 250 pm (e.g., 200 pm), inclusive. FIG. 11C illustrates an example where the top glass substrate 1102 is laser welded to the bottom glass substrate 1140 along a rim 1142.

[0069] FIG. 12 illustrates a device 1200 with a display 1202. The device 1200 may be a television or monitor, for example. The display 1202 includes the LED device 1100 of FIGS. 11 A, 1 IB, and 11C. For example, the top glass substrate 1102 is illustrated on the outside (e.g., the viewing side) of the display 1202, whereas the bottom glass substrate 1140 is on the inside of display 1202. Exemplary Embodiments

[0070] In some examples, a color converter plate includes a first glass substrate and a second glass substrate opposite the first glass substrate. The color converter plate also includes a metal material disposed between the first glass substrate and the second glass substrate. The metal material may be aluminum foil, for example, and includes a plurality of cavities for holding color converting material, such as a solution of quantum dots. In some examples, binary diffractive optical elements are deposited along a surface of the first glass substrate. In some examples, a surface of the second glass substrate is coated with a low emissivity material. The color converter device may be hermetically packaged and include light-emitting diode arrays to be used within LED displays, for example.

[0071] In some examples, a device comprises a first glass substrate and a second glass substrate opposite the first glass substrate. The device also comprises a metal material disposed between the first glass substrate and the second glass substrate. The metal material comprises a plurality of cavities for holding color converting material.

[0072] In some examples, the plurality of cavities include the color converting material. In some examples, the color converting material comprises quantum dots. In some examples, the quantum dots comprise red and green quantum dots.

[0073] In some examples, the metal material comprises aluminum foil. In some examples, a first side of the aluminum foil comprises the plurality of cavities.

[0074] In some examples, the plurality of cavities are concave.

[0075] In some examples, the device comprises optical elements deposited along the first glass substrate. In some examples, the optical elements comprise one or more of binary diffractive optical elements and thermally radiative SiC photonic structures. In some examples, the optical elements are deposited in a pattern to match a pitch of light emitting diode arrays.

[0076] In some examples, the device comprises a low emissivity material coated over the second glass substrate. In some examples, the device comprises a plurality of metallic leads.

[0077] In some embodiments, a light-emitting diode (LED) display comprises a first glass substrate and a second glass substrate opposite the first glass substrate. The LED display also comprises a metal material disposed between the first glass substrate and the second glass substrate. The metal material comprises a plurality of cavities for holding color converting material. [0078] In some examples, the plurality of cavities include the color converting material. In some examples, the color converting material comprises quantum dots. In some examples, the quantum dots comprise red and green quantum dots.

[0079] In some examples, the metal material comprises aluminum foil. In some examples, a first side of the aluminum foil comprises the plurality of cavities.

[0080] In some examples, the plurality of cavities are concave.

[0081] In some examples, the LED display comprises optical elements deposited on the first glass substrate. In some examples, the optical elements comprise one or more of binary diffractive optical elements and thermally radiative SiC photonic structures. In some examples, the optical elements are deposited in a pattern to match a pitch of light emitting diode arrays.

[0082] In some examples, the LED display comprises a low emissivity material coated over the second glass substrate. In some examples, the device comprises a plurality of metallic leads.

[0083] In some examples, a method comprises disposing a metal material on a first glass substrate, where the metal material comprises a plurality of cavities for holding color converting material. The method also comprises filling the plurality of cavities with the color converting material. Further, the method comprises disposing a second glass substrate on the metal material.

[0084] In some examples, the plurality of cavities include the color converting material. In some examples, the color converting material comprises quantum dots. In some examples, the quantum dots comprise red and green quantum dots.

[0085] In some examples, the metal material comprises aluminum foil. In some examples, a first side of the aluminum foil comprises the plurality of cavities.

[0086] In some examples, the plurality of cavities are concave.

[0087] In some examples, the method comprises depositing binary diffractive optical elements along the first glass substrate. In some examples, the binary diffractive optical elements comprise thermally radiative SiC photonic structures. In some examples, the binary diffractive optical elements are deposited in a pattern to match a pitch of light emitting diode arrays.

[0088] In some examples, the method comprises applying a coat of low emissivity material over the second glass substrate.

[0089] In some embodiments, a non-transitory computer readable medium stores instructions that, when executed by one or more processors, cause the one or more processors to perform a method that includes disposing a metal material on a first glass substrate, where the metal material comprises a plurality of cavities for holding color converting material. The method also comprises filling the plurality of cavities with the color converting material. Further, the method comprises disposing a second glass substrate on the metal material.

[0090] In some examples, the plurality of cavities include the color converting material. In some examples, the color converting material comprises quantum dots. In some examples, the quantum dots comprise red and green quantum dots.

[0091] In some examples, the metal material comprises aluminum foil. In some examples, a first side of the aluminum foil comprises the plurality of cavities.

[0092] In some examples, the plurality of cavities are concave.

[0093] In some examples, the method comprises depositing binary diffractive optical elements along the first glass substrate. In some examples, the binary diffractive optical elements comprise thermally radiative SiC photonic structures. In some examples, the binary diffractive optical elements are deposited in a pattern to match a pitch of light emitting diode arrays.

[0094] In some examples, the method comprises applying a coat of low emissivity material over the second glass substrate.

[0095] In some examples, a color converter plate includes a first glass substrate, and a metal layer disposed along a perimeter of the first glass substrate. The device also includes a mask positioned on the metal layer, wherein the mask includes a plurality of openings to hold a solution of color conversion elements. The device further includes a second glass substrate positioned over the mask and sealed to the mask.

[0096] In some examples, alternating rows of the plurality of openings of the mask include quantum dots of a varying type (e.g., color). In some examples, the second glass substrate is laser-welded to the mask.

[0097] In some examples, a hermetic glass package contains active and passive elements introduced during assembly to include LED arrays, embedded or otherwise.

[0098] Although the methods described above are with reference to the illustrated flowcharts, it will be appreciated that many other ways of performing the acts associated with the methods can be used. For example, the order of some operations may be changed, and some of the operations described may be optional.

[0099] In addition, the methods and system described herein can be at least partially embodied in the form of computer-implemented processes and apparatus for practicing those processes. The disclosed methods may also be at least partially embodied in the form of tangible, non-transitory machine-readable storage media encoded with computer program code. For example, the steps of the methods can be embodied in hardware, in executable instructions executed by a processor (e.g., software), or a combination of the two. The media may include, for example, RAMs, ROMs, CD-ROMs, DVD-ROMs, BD- ROMs, hard disk drives, flash memories, or any other non-transitory machine-readable storage medium. When the computer program code is loaded into and executed by a computer, the computer becomes an apparatus for practicing the method. The methods may also be at least partially embodied in the form of a computer into which computer program code is loaded or executed, such that, the computer becomes a special purpose computer for practicing the methods. When implemented on a general-purpose processor, the computer program code segments configure the processor to create specific logic circuits. The methods may alternatively be at least partially embodied in application specific integrated circuits for performing the methods.

[00100] The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of this disclosure. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of this disclosure.

Claims

CLAIMS What is claimed is:

1. A device comprising: a first glass substrate and a second glass substrate opposite the first glass substrate; and a metal material disposed between the first glass substrate and the second glass substrate, wherein the metal material comprises a plurality of cavities.

2. The device of claim 1, wherein the plurality of cavities include the color converting material.

3. The device of claim 2, wherein the color converting material comprises quantum dots.

4. The device of claim 3, wherein the quantum dots comprise red and green quantum dots.

5. The device of claim 1, wherein the metal material comprises aluminum foil.

6. The device of claim 1, wherein the first glass substrate is welded to the metal material.

7. The device of claim 6, wherein the second glass substrate is welded to the metal material.

8. The device of claim 1, wherein optical elements are deposited on the first glass substrate.

9. The device of claim 8, wherein the optical elements comprise binary diffractive optical elements.

10. The device of claim 8, wherein the optical elements are deposited in a pattern to match a pitch of light emitting diode arrays.

11. The device of claim 1, wherein the second glass substrate is coated with a low emissivity material having a thermal emissivity between .02 and .05, inclusive.

12. A light-emitting diode (LED) device comprising: a first glass substrate and a second glass substrate opposite the first glass substrate; a metal material disposed between the first glass substrate and the second glass substrate, wherein the metal material comprises a plurality of cavities; and a plurality of LED arrays disposed between the metal material and the second glass substrate.

13. The LED device of claim 12, wherein the plurality of cavities include color converting material.

14. The LED device of claim 13, wherein the color converting material comprises quantum dots.

15. The LED device of claim 12, wherein the metal material comprises aluminum foil.

16. The LED device of claim 12, comprising metal leads coupled to the LED array.

17. The LED device of claim 12, wherein optical elements are deposited on the first glass substrate.

18. The LED device of claim 12, wherein the optical elements are deposited in a pattern to match a pitch of the plurality of LED arrays.

19. The LED device of claim 12, wherein the second glass substrate is coated with a low emissivity material having a thermal emissivity between .02 and .05, inclusive.

20. A method comprising: disposing a metal material on a first glass substrate, wherein the metal material comprises a plurality of cavities; filling the plurality of cavities with the color converting material; and disposing a second glass substrate on the metal material.