WO2017184941A1 - Small pitch direct view display and method of making thereof - Google Patents

Small pitch direct view display and method of making thereof Download PDF

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Publication number
WO2017184941A1
WO2017184941A1 PCT/US2017/028771 US2017028771W WO2017184941A1 WO 2017184941 A1 WO2017184941 A1 WO 2017184941A1 US 2017028771 W US2017028771 W US 2017028771W WO 2017184941 A1 WO2017184941 A1 WO 2017184941A1
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WO
WIPO (PCT)
Prior art keywords
pixels
display device
view display
direct view
isolation grid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2017/028771
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French (fr)
Inventor
Neil Deeman
Michael Jansen
Hyung-Chul Lee
Kai Liu
Kazunori Okui
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Individual
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Individual
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Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to EP17786687.8A priority Critical patent/EP3446330A4/en
Priority to JP2018554745A priority patent/JP2019515489A/en
Priority to KR1020187031032A priority patent/KR20180128464A/en
Publication of WO2017184941A1 publication Critical patent/WO2017184941A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0274—Optical details, e.g. printed circuits comprising integral optical means
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/18—Printed circuits structurally associated with non-printed electric components
    • H05K1/181—Printed circuits structurally associated with non-printed electric components associated with surface mounted components
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/22—Secondary treatment of printed circuits
    • H05K3/28—Applying non-metallic protective coatings
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/22—Secondary treatment of printed circuits
    • H05K3/28—Applying non-metallic protective coatings
    • H05K3/284—Applying non-metallic protective coatings for encapsulating mounted components
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/30—Assembling printed circuits with electric components, e.g. with resistors
    • H05K3/303—Assembling printed circuits with electric components, e.g. with resistors with surface mounted components
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
    • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
    • H10H20/80—Constructional details
    • H10H20/84—Coatings, e.g. passivation layers or antireflective coatings
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
    • H10W90/00—Package configurations
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/04—Structural and physical details of display devices
    • G09G2300/0404—Matrix technologies
    • G09G2300/0408—Integration of the drivers onto the display substrate
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/04—Structural and physical details of display devices
    • G09G2300/0439—Pixel structures
    • G09G2300/0452—Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/01—Dielectrics
    • H05K2201/0104—Properties and characteristics in general
    • H05K2201/0112—Absorbing light, e.g. dielectric layer with carbon filler for laser processing
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10007—Types of components
    • H05K2201/10106—Light emitting diode [LED]
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10007—Types of components
    • H05K2201/10128—Display
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10431—Details of mounted components
    • H05K2201/10507—Involving several components
    • H05K2201/10522—Adjacent components
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/13—Moulding and encapsulation; Deposition techniques; Protective layers
    • H05K2203/1305—Moulding and encapsulation
    • H05K2203/1316—Moulded encapsulation of mounted components

Definitions

  • the present disclosure relates to direct view display devices, and particularly to LED based small pitch direct display devices with an isolation grid and methods of fabricating the same.
  • a LED (light emitting diode) based direct view display is a display in which the LEDs are arranged in pixels and the image of the display is formed by turning the LEDs in each pixel on and off.
  • This type of device differs from a LED backlit liquid crystal display (LCD) in which the pixels contain a liquid crystal material which is backlit by light (e.g., white light) emitted by a LED backlight.
  • LCD liquid crystal display
  • a direct view display device includes a printed circuit board, an array of pixels located on a first side of the printed circuit board, each pixel including a plurality of light emitting diodes, and an isolation grid comprising a light absorbing material located between the pixels in the array of pixels.
  • a method of forming a direct view display device comprises providing a printed circuit board, attaching light emitting diodes to a first side of the printed circuit board to form an array of pixels, each pixel comprising a plurality of light emitting diodes, and providing an isolation grid comprising a light absorbing material between the pixels in the array of pixels.
  • FIGS. 1A, IB and 1C are respective top, side and bottom views of a direct view display device according to an embodiment of the present disclosure.
  • FIGS. 2A and 2B are respective magnified top view and side cross sectional view of the direct view display device of an embodiment of the present disclosure.
  • FIG. 3 is a top view of an isolation grid that provides lateral optical isolation according to an embodiment of the present disclosure.
  • FIGS. 4A-4D show steps in a manufacturing sequence that can be employed to fabricate a direct view display device of the present disclosure.
  • FIGS. 4A and 4B are bottom views
  • FIG. 4C is a top view
  • FIG. 4D is a perspective view of the display device.
  • a LED based small pitch direct view display device including an isolation grid
  • the direct view display device may be a multi-color or black and white display device which contains a red light emitting LED, blue light emitting LED and a green light emitting LED (i.e., RGB LEDs) in each pixel.
  • the pixels preferably contain no liquid crystal material.
  • the pitch of the LED pixels is preferably less than 1.5 mm, such as 5 microns to 1.2 mm.
  • the display device with a pixel pitch of 0.9 to 1.2 mm can be used for electronic display signage applications
  • the display device with a pixel pitch of 50 microns to 1.2 mm can be used in electronic device displays, such as tablet, phone or watch displays
  • the display device with a pixel pitch of 5 microns to 10 microns can be used for virtual reality or augmented reality devices (e.g., such as virtual reality goggles).
  • a LED based direct view device 1 of an embodiment of the present disclosure is shown in FIGS. 1A-1C.
  • the device 1 contains a substrate 2, such as a printed circuit board (PCB).
  • the LEDs 10, such as RGB LEDs, are mounted on the top surface of the substrate 2.
  • Driver electronics 20, such as logic and/or control chips, contact pads 22 and electrodes (e.g., electrical contacts or pins) 24 are mounted on the bottom side of the substrate 2.
  • an isolation grid 30 of light absorbing material can be provided between the pixels 100 of the device 1, as illustrated in FIGS. 2A, 2B and 3.
  • Each pixel 100 may contain a red light emitting LED 10R, blue light emitting LED 10B and a green light emitting LED 10G. More than one LED 10 of one or more colors may be provided in each pixel 100.
  • Each pixel 100 may also contain electrical contacts, sensor devices, and other electronics as needed.
  • the isolation grid 30 significantly reduces the optical interference between adjacent pixels (e.g., RGB pixels) 100.
  • the top of the isolation grid can be at least at the same level as (i.e., at the same level or protrude above) the top of the LEDs 10. In one embodiment, the top of the isolation grid can protrude above the plane including the topmost surfaces of the LED 10 dies.
  • the isolation grid 30 can be applied before or after the LEDs 10 are mounted on the substrate 2, such as the printed circuit board (PCB).
  • the isolation grid 30 can be manufactured employing two-dimensional (2D) printing or three- dimensional (3D) printing using ultraviolet (UV) curable or thermal applied material directly onto the PCB surface.
  • the isolation material of the isolation grid can be a black UV curable ink.
  • the isolation grid 30 can be manufactured by injection molding a plastic material to form a free-standing isolation grid, as shown in FIG. 3, and subsequently attaching the free-standing grid to the top PCB substrate 2 surface.
  • the isolation material of the isolation grid can be a black colored polycarbonate plastic material.
  • FIG. 3 shows an exemplary criss-cross pattern that can be employed for the isolation grid 30.
  • the isolation grid 30 has a rectangular array of openings therein. In another embodiment, the isolation grid 30 has a hexagonal array of openings therein.
  • the isolation grid 30 containing direct view display devices 1 of the present disclosure provide improvement over prior art display devices.
  • Optical interference from adjacent LED pixels 100 which would result in light emission from an apparently larger region than the physical area of the LED pixel 100 provided by design, can be significantly reduced.
  • Reduction of optional interference has the effect of enhancing the optical resolution of the display device.
  • FIGS. 4A to 4D illustrate an exemplary process sequence that may be employed to manufacture the direct view display device 1 of the present disclosure.
  • the electronic components (20, 22, 24) are mounted to the bottom side of the PCB substrate 2 in a first step.
  • the electronic components are then encapsulated in a planarizing
  • the planarizing encapsulation material of the bottom encapsulation layer 40 can include, e.g. Bakelite or epoxy molding compound (EMC).
  • EMC epoxy molding compound
  • the planarizing encapsulation material 40 is compatible with the third and fourth steps described below.
  • the thickness of the bottom encapsulation layer 40 can be in a range from 30 microns to 10 mm, although lesser and greater thicknesses can also be used.
  • a third step of mounting the LEDs 10 and forming the isolation grid 30 on the top side of the substrate 2 is then performed, as shown in FIG. 4C.
  • the LEDs 10 can be mounted to the top side of the substrate 2 in a pixel arrangement, followed by printing a UV or thermally curable ink between the pixels 100. The ink in then UV cured or thermally cured to form the isolation grid 30.
  • the free-standing isolation grid 30 can be formed separately from the substrate 2 followed by attaching the free-standing isolation grid 30 to the top side of the substrate 2 before or after mounting the LEDs 10.
  • a top encapsulation layer 50 is formed on the LEDs 10 and the isolation grid 30 over the top side of the substrate 2, as shown in FIG. 4D.
  • the second encapsulation process of the fourth step is aided by the presence of the bottom encapsulation layer 40 formed in the second step such that the pressure exerted on the PCB substrate 2 is more evenly distributed during the fourth step, thereby preventing cracking, bending or other damage to the assembly.
  • a relatively thin transparent coating layer 60 can be formed over the top encapsulation layer 50.
  • the thickness of the top encapsulation layer 50 can be in a range from 30 microns to 1 mm, although lesser and greater thicknesses can also be used.
  • the thickness of the second encapsulation layer 60 can be in a range from 10 microns to 300 microns, although lesser and greater thicknesses can also be employed.
  • Encapsulation materials that can be used for the top encapsulation layer 50 can be optically transparent silicones.
  • the surface properties of these types of materials lend themselves to easy pick up of contamination from fingerprints and dust that can impair the optical transmission.
  • This surface can be modified by the application of the transparent coating layer 60 that is thinner than top encapsulation layer 50, binds strongly to the second encapsulation layer 50, and is resistant to contamination build up.
  • An example of such a material for layer 60 is a contamination-resistant material, such as KJC-7022 made by Shin Etsu Chemical. This material does not have the required properties to replace the LED encapsulant entirely but can modify the surface properties sufficiently to have the desired effect.
  • a stack of a transparent top encapsulation layer 50 and a transparent coating layer 60 made from a material resistant to surface contamination can be employed to enhance display properties of a direct view display device.
  • the electronic components (20, 22, 24) which are mounted to the bottom surface of the PCB substrate 2 are protected from damage by the bottom encapsulation layer 40 during the mounting of the LEDs 10 and formation of the isolation grid 30 on the top side of the substrate 2 and during the product life. Furthermore, the top, outer viewable surface of the device 1 is protected from build-up of contamination (e.g., finger prints, dust etc.) that can reduce light output, and can be cleaned to return it to its original optical output due to the presence of the transparent coating layer 60.
  • contamination e.g., finger prints, dust etc.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)
  • Led Device Packages (AREA)

Abstract

A direct view display device includes a printed circuit board, an array of pixels located on a first side of the printed circuit board, each pixel including a plurality of light emitting diodes, and an isolation grid comprising a light absorbing material located between the pixels in the array of pixels.

Description

SMALL PITCH DIRECT VIEW DISPLAY
AND METHOD OF MAKING THEREOF
RELATED APPLICATIONS
[0001] This application claims the benefit of priority from U.S. Provisional Application
Serial No. 62/326,255 filed on April 22, 2016, the entire contents of which are incorporated herein by reference.
FIELD
[0002] The present disclosure relates to direct view display devices, and particularly to LED based small pitch direct display devices with an isolation grid and methods of fabricating the same.
BACKGROUND
[0003] A LED (light emitting diode) based direct view display is a display in which the LEDs are arranged in pixels and the image of the display is formed by turning the LEDs in each pixel on and off. This type of device differs from a LED backlit liquid crystal display (LCD) in which the pixels contain a liquid crystal material which is backlit by light (e.g., white light) emitted by a LED backlight.
SUMMARY
[0004] According to an aspect of the present disclosure, a direct view display device includes a printed circuit board, an array of pixels located on a first side of the printed circuit board, each pixel including a plurality of light emitting diodes, and an isolation grid comprising a light absorbing material located between the pixels in the array of pixels. [0005] According to another aspect of the present disclosure, a method of forming a direct view display device comprises providing a printed circuit board, attaching light emitting diodes to a first side of the printed circuit board to form an array of pixels, each pixel comprising a plurality of light emitting diodes, and providing an isolation grid comprising a light absorbing material between the pixels in the array of pixels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIGS. 1A, IB and 1C are respective top, side and bottom views of a direct view display device according to an embodiment of the present disclosure.
[0007] FIGS. 2A and 2B are respective magnified top view and side cross sectional view of the direct view display device of an embodiment of the present disclosure.
[0008] FIG. 3 is a top view of an isolation grid that provides lateral optical isolation according to an embodiment of the present disclosure.
[0009] FIGS. 4A-4D show steps in a manufacturing sequence that can be employed to fabricate a direct view display device of the present disclosure. FIGS. 4A and 4B are bottom views, FIG. 4C is a top view and FIG. 4D is a perspective view of the display device.
DETAILED DESCRIPTION
[0010] According to an aspect of the present disclosure, a LED based small pitch direct view display device including an isolation grid is provided. The direct view display device may be a multi-color or black and white display device which contains a red light emitting LED, blue light emitting LED and a green light emitting LED (i.e., RGB LEDs) in each pixel. In one embodiment, the pixels preferably contain no liquid crystal material. The pitch of the LED pixels is preferably less than 1.5 mm, such as 5 microns to 1.2 mm. For example, the display device with a pixel pitch of 0.9 to 1.2 mm can be used for electronic display signage applications, the display device with a pixel pitch of 50 microns to 1.2 mm can be used in electronic device displays, such as tablet, phone or watch displays, and the display device with a pixel pitch of 5 microns to 10 microns can be used for virtual reality or augmented reality devices (e.g., such as virtual reality goggles). [0011] A LED based direct view device 1 of an embodiment of the present disclosure is shown in FIGS. 1A-1C. The device 1 contains a substrate 2, such as a printed circuit board (PCB). The LEDs 10, such as RGB LEDs, are mounted on the top surface of the substrate 2. Driver electronics 20, such as logic and/or control chips, contact pads 22 and electrodes (e.g., electrical contacts or pins) 24 are mounted on the bottom side of the substrate 2.
[0012] In one embodiment of the present disclosure, an isolation grid 30 of light absorbing material can be provided between the pixels 100 of the device 1, as illustrated in FIGS. 2A, 2B and 3. Each pixel 100 may contain a red light emitting LED 10R, blue light emitting LED 10B and a green light emitting LED 10G. More than one LED 10 of one or more colors may be provided in each pixel 100. Each pixel 100 may also contain electrical contacts, sensor devices, and other electronics as needed.
[0013] The isolation grid 30 significantly reduces the optical interference between adjacent pixels (e.g., RGB pixels) 100. In one embodiment shown in FIG. 2B, the top of the isolation grid can be at least at the same level as (i.e., at the same level or protrude above) the top of the LEDs 10. In one embodiment, the top of the isolation grid can protrude above the plane including the topmost surfaces of the LED 10 dies.
[0014] In one embodiment, the isolation grid 30 can be applied before or after the LEDs 10 are mounted on the substrate 2, such as the printed circuit board (PCB). In one embodiment, the isolation grid 30 can be manufactured employing two-dimensional (2D) printing or three- dimensional (3D) printing using ultraviolet (UV) curable or thermal applied material directly onto the PCB surface. In one embodiment, the isolation material of the isolation grid can be a black UV curable ink.
[0015] In another embodiment, the isolation grid 30 can be manufactured by injection molding a plastic material to form a free-standing isolation grid, as shown in FIG. 3, and subsequently attaching the free-standing grid to the top PCB substrate 2 surface. In one embodiment, the isolation material of the isolation grid can be a black colored polycarbonate plastic material. FIG. 3 shows an exemplary criss-cross pattern that can be employed for the isolation grid 30. In one embodiment, the isolation grid 30 has a rectangular array of openings therein. In another embodiment, the isolation grid 30 has a hexagonal array of openings therein.
[0016] The isolation grid 30 containing direct view display devices 1 of the present disclosure provide improvement over prior art display devices. Optical interference from adjacent LED pixels 100, which would result in light emission from an apparently larger region than the physical area of the LED pixel 100 provided by design, can be significantly reduced. Reduction of optional interference has the effect of enhancing the optical resolution of the display device.
[0017] FIGS. 4A to 4D illustrate an exemplary process sequence that may be employed to manufacture the direct view display device 1 of the present disclosure. As shown in FIG. 4A, the electronic components (20, 22, 24) are mounted to the bottom side of the PCB substrate 2 in a first step. The electronic components are then encapsulated in a planarizing
encapsulation material which forms a bottom encapsulation layer 40 in a second step, as shown in FIG. 4B. The planarizing encapsulation material of the bottom encapsulation layer 40 can include, e.g. Bakelite or epoxy molding compound (EMC). The planarizing encapsulation material 40 is compatible with the third and fourth steps described below. The thickness of the bottom encapsulation layer 40 can be in a range from 30 microns to 10 mm, although lesser and greater thicknesses can also be used.
[0018] A third step of mounting the LEDs 10 and forming the isolation grid 30 on the top side of the substrate 2 is then performed, as shown in FIG. 4C. For example, the LEDs 10 can be mounted to the top side of the substrate 2 in a pixel arrangement, followed by printing a UV or thermally curable ink between the pixels 100. The ink in then UV cured or thermally cured to form the isolation grid 30. Alternatively, the free-standing isolation grid 30 can be formed separately from the substrate 2 followed by attaching the free-standing isolation grid 30 to the top side of the substrate 2 before or after mounting the LEDs 10.
[0019] In a fourth step, a top encapsulation layer 50 is formed on the LEDs 10 and the isolation grid 30 over the top side of the substrate 2, as shown in FIG. 4D. The second encapsulation process of the fourth step is aided by the presence of the bottom encapsulation layer 40 formed in the second step such that the pressure exerted on the PCB substrate 2 is more evenly distributed during the fourth step, thereby preventing cracking, bending or other damage to the assembly.
[0020] According to another embodiment of the present disclosure, a relatively thin transparent coating layer 60 can be formed over the top encapsulation layer 50. The thickness of the top encapsulation layer 50 can be in a range from 30 microns to 1 mm, although lesser and greater thicknesses can also be used. The thickness of the second encapsulation layer 60 can be in a range from 10 microns to 300 microns, although lesser and greater thicknesses can also be employed.
[0021] Encapsulation materials that can be used for the top encapsulation layer 50 can be optically transparent silicones. The surface properties of these types of materials lend themselves to easy pick up of contamination from fingerprints and dust that can impair the optical transmission. This surface can be modified by the application of the transparent coating layer 60 that is thinner than top encapsulation layer 50, binds strongly to the second encapsulation layer 50, and is resistant to contamination build up. An example of such a material for layer 60 is a contamination-resistant material, such as KJC-7022 made by Shin Etsu Chemical. This material does not have the required properties to replace the LED encapsulant entirely but can modify the surface properties sufficiently to have the desired effect. Thus, a stack of a transparent top encapsulation layer 50 and a transparent coating layer 60 made from a material resistant to surface contamination can be employed to enhance display properties of a direct view display device.
[0022] Thus, the electronic components (20, 22, 24) which are mounted to the bottom surface of the PCB substrate 2 are protected from damage by the bottom encapsulation layer 40 during the mounting of the LEDs 10 and formation of the isolation grid 30 on the top side of the substrate 2 and during the product life. Furthermore, the top, outer viewable surface of the device 1 is protected from build-up of contamination (e.g., finger prints, dust etc.) that can reduce light output, and can be cleaned to return it to its original optical output due to the presence of the transparent coating layer 60.
[0023] The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein.

Claims

1. A direct view display device comprising:
a printed circuit board;
an array of pixels located on a first side of the printed circuit board, each pixel comprising a plurality of light emitting diodes (LEDs); and
an isolation grid comprising a light absorbing material located between the pixels in the array of pixels.
2. The direct view display device of Claim 1, wherein each pixel comprises a red light emitting LED, a blue light emitting LED and a green light emitting LED.
3. The direct view display device of Claim 1, wherein the isolation grid extends at least up to a height of a topmost surface of the array of pixels.
4. The direct view display device of Claim 1, wherein the isolation grid comprises a freestanding grid made of a plastic light absorbing material.
5. The direct view display device of Claim 4, wherein the light absorbing material comprises a black colored polycarbonate plastic material.
6. The direct view display device of Claim 1, wherein the isolation grid comprises a printed UV curable or thermally applied material.
7. The direct view display device of Claim 6, wherein the light absorbing material comprises a printed and UV cured black ink.
8. The direct view display device of Claim 1, further comprising a first transparent encapsulation material layer located over the isolation grid and the array of pixels.
9. The direct view display device of Claim 8, further comprising a contamination-resistant transparent coating layer located on the first transparent encapsulation material and comprising a material that is more resistant to pick-up of contaminants than the transparent encapsulation material layer.
10. The direct view display device of Claim 8, further comprising:
driver electronics mounted on a second side of the printed circuit board; and a second encapsulation material layer located over the driver electronics.
11. A method of forming a direct view display device, comprising:
providing a printed circuit board;
attaching light emitting diodes (LEDs) to a first side of the printed circuit board to form an array of pixels, each pixel comprising a plurality of the LEDs; and
providing an isolation grid comprising a light absorbing material between the pixels in the array of pixels.
12. The method of Claim 11, wherein each pixel comprises a red light emitting LED, a blue light emitting LED and a green light emitting LED.
13. The method of Claim 11, wherein the isolation grid extends at least up to a height of a topmost surface of the array of pixels.
14. The method of Claim 11, wherein providing the isolation grid comprises forming a freestanding isolation grid made of a plastic light absorbing material and attaching the freestanding isolation grid to the first side of the printed circuit board.
15. The method of Claim 14, wherein the light absorbing material comprises injection molded, black colored polycarbonate plastic material.
16. The method of Claim 11, wherein providing the isolation grid comprises printing a UV curable or thermally applied material between the pixels on the first side of the printed circuit board.
17. The method of Claim 16, wherein the light absorbing material comprises a printed, UV curable black ink which is UV cured after being printed.
18. The method of Claim 11, further comprising forming a first transparent encapsulation material layer over the isolation grid and the array of pixels.
19. The method of Claim 8, further comprising forming contamination-resistant transparent coating layer on the first transparent encapsulation material, the contamination-resistant transparent coating layer comprising a material that is more resistant to pick-up of contaminants than the transparent encapsulation material layer.
20. The method of Claim 18, further comprising:
mounting driver electronics on a second side of the printed circuit board; and forming a second encapsulation material layer over the driver electronics prior to attaching the light emitting diodes to the first side of the printed circuit board.
PCT/US2017/028771 2016-04-22 2017-04-21 Small pitch direct view display and method of making thereof Ceased WO2017184941A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111464803A (en) * 2020-04-16 2020-07-28 中国长城科技集团股份有限公司 Display control system

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180210195A1 (en) * 2017-01-24 2018-07-26 Microsoft Technology Licensing, Llc Avoiding ghost images
CN208862011U (en) * 2017-01-24 2019-05-14 平面系统公司 Direct View Light Emitting Diode Display Device
KR102532307B1 (en) 2017-11-02 2023-05-15 삼성디스플레이 주식회사 Display device
US10269711B1 (en) * 2018-03-16 2019-04-23 Taiwan Semiconductor Manufacturing Company Ltd. Semiconductor device and method for manufacturing the same
US10627673B2 (en) 2018-04-06 2020-04-21 Glo Ab Light emitting diode array containing a multilayer bus electrode and method of making the same
WO2020227627A2 (en) * 2019-05-09 2020-11-12 Daktronics, Inc. Molded contrast mask for display module
FR3097981B1 (en) * 2019-06-28 2021-07-02 Valeo Vision Lighting device for motor vehicle
HUE065603T2 (en) * 2019-10-07 2024-06-28 Essilor Int Characterizing an optical element
US11594663B2 (en) 2019-12-20 2023-02-28 Nanosys, Inc. Light emitting diode device containing a micro lens array and method of making the same
TWI719775B (en) * 2019-12-25 2021-02-21 錼創顯示科技股份有限公司 Display device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140021493A1 (en) * 2012-07-20 2014-01-23 Peter Andrews Solid state lighting component package with layer
US20150069429A1 (en) * 2007-05-31 2015-03-12 Nthdegree Technologies Worldwide Inc. Method of Manufacturing Addressable and Static Electronic Displays
KR20150094733A (en) * 2012-12-13 2015-08-19 픽스트로닉스 인코포레이티드 Display with light modulating pixels organized in off-axis arrangement
US20160043061A1 (en) * 2013-04-01 2016-02-11 Lg Electronics Inc. Display device using semiconductor light emitting device
WO2016057588A2 (en) * 2014-10-07 2016-04-14 Corning Incorporated Direct view display device and light unit for direct view display device

Family Cites Families (62)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0553511A (en) * 1991-08-28 1993-03-05 Toyoda Gosei Co Ltd Color display device
JPH08202290A (en) * 1995-01-26 1996-08-09 Daihatsu Motor Co Ltd Led display module
US6589650B1 (en) * 2000-08-07 2003-07-08 3M Innovative Properties Company Microscope cover slip materials
JP4049624B2 (en) 2001-07-27 2008-02-20 株式会社エンプラス Surface light source device, image display device, and light guide plate
JP4223740B2 (en) 2002-06-13 2009-02-12 シチズン電子株式会社 Light emitting device package
US7335908B2 (en) 2002-07-08 2008-02-26 Qunano Ab Nanostructures and methods for manufacturing the same
US20040061810A1 (en) 2002-09-27 2004-04-01 Lumileds Lighting, U.S., Llc Backlight for a color LCD using wavelength-converted light emitting devices
TWI351566B (en) 2003-01-15 2011-11-01 Semiconductor Energy Lab Liquid crystal display device
US8270061B2 (en) 2003-11-01 2012-09-18 Silicon Quest Kabushiki-Kaisha Display apparatus using pulsed light source
US7132677B2 (en) 2004-02-13 2006-11-07 Dongguk University Super bright light emitting diode of nanorod array structure having InGaN quantum well and method for manufacturing the same
TWI367686B (en) * 2004-04-07 2012-07-01 Semiconductor Energy Lab Light emitting device, electronic device, and television device
GB0408347D0 (en) 2004-04-15 2004-05-19 Design Led Products Ltd Light guide device
US7204631B2 (en) 2004-06-30 2007-04-17 3M Innovative Properties Company Phosphor based illumination system having a plurality of light guides and an interference reflector
US8128272B2 (en) 2005-06-07 2012-03-06 Oree, Inc. Illumination apparatus
EP1954983B1 (en) 2005-11-21 2015-01-07 Philips Intellectual Property & Standards GmbH Optical system
JP4669799B2 (en) 2006-03-01 2011-04-13 パナソニック株式会社 Edge input type backlight
WO2007102781A1 (en) 2006-03-08 2007-09-13 Qunano Ab Method for metal-free synthesis of epitaxial semiconductor nanowires on si
KR101019941B1 (en) 2006-03-10 2011-03-09 에스티씨. 유엔엠 Pulse Growth of JAN Nanowires and Applications in Group III-nitride Semiconductor Substrate Materials and Devices
JP4585481B2 (en) 2006-04-28 2010-11-24 株式会社 日立ディスプレイズ LED backlight and liquid crystal display device using the same
GB2438440B (en) 2006-05-26 2008-04-23 Design Led Products Ltd A composite light guiding device
US20090128781A1 (en) 2006-06-13 2009-05-21 Kenneth Li LED multiplexer and recycler and micro-projector incorporating the Same
US20080049445A1 (en) 2006-08-25 2008-02-28 Philips Lumileds Lighting Company, Llc Backlight Using High-Powered Corner LED
US20080080184A1 (en) * 2006-10-03 2008-04-03 Cao Group Inc. Pixilated LED Light Source for Channel Letter Illumination
CN101681813B (en) 2007-01-12 2012-07-11 昆南诺股份有限公司 Nitride nanowires and method of producing the same
JP4613947B2 (en) 2007-12-07 2011-01-19 ソニー株式会社 Illumination device, color conversion element, and display device
JP2009177117A (en) * 2007-12-25 2009-08-06 Toshiba Lighting & Technology Corp Display device
WO2009133870A1 (en) 2008-04-30 2009-11-05 アルプス電気株式会社 Illuminating apparatus and method for manufacturing the same
GB2459888B (en) 2008-05-09 2011-06-08 Design Led Products Ltd Capacitive sensing apparatus
GB0809385D0 (en) 2008-05-23 2008-07-02 Design Led Products Ltd Light-guide apparatus
EP2128689A1 (en) * 2008-05-27 2009-12-02 Barco NV A display panel with improved reflectivity
JP5512515B2 (en) 2008-05-30 2014-06-04 シャープ株式会社 Light emitting device, surface light source, and liquid crystal display device
JP2010021131A (en) 2008-06-09 2010-01-28 Hitachi Ltd Display device and backlight unit used for the same
KR20110039313A (en) 2008-07-07 2011-04-15 글로 에이비 Nanostructure LED
KR100953655B1 (en) * 2008-07-08 2010-04-20 삼성모바일디스플레이주식회사 Organic light emitting diode display
KR100924912B1 (en) 2008-07-29 2009-11-03 서울반도체 주식회사 Warm white light emitting apparatus and back light module comprising the same
US8755005B2 (en) 2008-09-24 2014-06-17 Koninklijke Philips N.V. Thin edge backlight with LEDS optically coupled to the back surface
US7717584B1 (en) * 2008-11-28 2010-05-18 Wei-Jei Tuan Vibrating and twinkling LED backlighting device
JP5407545B2 (en) * 2009-05-19 2014-02-05 ソニー株式会社 Anti-glare film, method for producing the same, and display device
JP2011065010A (en) 2009-09-18 2011-03-31 Panasonic Corp Image forming apparatus
JP5531629B2 (en) 2010-01-14 2014-06-25 凸版印刷株式会社 Backlight unit and display device
GB201008599D0 (en) 2010-05-24 2010-07-07 Design Led Products Ltd Light guide device
GB201008601D0 (en) 2010-05-24 2010-07-07 Design Led Products Ltd Lighting apparatus
KR101147988B1 (en) * 2010-07-13 2012-05-24 포항공과대학교 산학협력단 Method of manufacturing flexible electronic device using physical peel-off method, flexible electronic device and flexible substrate
KR20120035062A (en) 2010-10-04 2012-04-13 삼성코닝정밀소재 주식회사 Back light unit
US8585268B2 (en) 2011-10-21 2013-11-19 Ergophos, Llc Light-guide panel for display with laser backlight
CN104024931B (en) * 2011-12-27 2017-04-05 夏普株式会社 Liquid crystal indicator, light control film, display device
US20130258216A1 (en) 2012-03-30 2013-10-03 Shin-Gwo Shiue Pico projection light system
CN103384179B (en) * 2012-05-04 2017-08-11 电信科学技术研究院 Use the uplink-downlink configuration method and equipment in the system of time division duplex communication standard
KR101452768B1 (en) 2012-08-21 2014-10-21 엘지전자 주식회사 Display device using semiconductor light emitting device and method of fabricating the same
KR101940761B1 (en) * 2012-10-16 2019-04-10 엘지디스플레이 주식회사 Organic Light Emitting diode display
JP6565129B2 (en) * 2013-02-15 2019-08-28 東洋紡株式会社 Image display device
JP2014229356A (en) * 2013-05-17 2014-12-08 ソニー株式会社 Light emitting element and method for manufacturing the same, and display device
US9111464B2 (en) * 2013-06-18 2015-08-18 LuxVue Technology Corporation LED display with wavelength conversion layer
WO2015042537A1 (en) 2013-09-23 2015-03-26 Glo Ab Integrated back light unit
WO2015095049A1 (en) 2013-12-17 2015-06-25 Glo Ab Iii-nitride nanowire led with strain modified surface active region and method of making thereof
KR20150093284A (en) 2014-02-06 2015-08-18 삼성디스플레이 주식회사 Backlight unit
US10833054B2 (en) 2014-02-08 2020-11-10 Cree Huizhou Solid State Lighting Company Limited Smart pixel surface mount device package
JP6429102B2 (en) * 2014-04-22 2018-11-28 大日本印刷株式会社 Image display device
KR20160000096A (en) * 2014-06-23 2016-01-04 삼성디스플레이 주식회사 Display device
TW201614347A (en) 2014-08-12 2016-04-16 Glo Ab Integrated back light unit including non-uniform light guide unit
JP3203462U (en) * 2016-01-19 2016-03-31 株式会社スリーエス Display device
KR102572819B1 (en) * 2016-02-23 2023-08-30 쑤저우 레킨 세미컨덕터 컴퍼니 리미티드 Fabricating method for light emitting module and display device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150069429A1 (en) * 2007-05-31 2015-03-12 Nthdegree Technologies Worldwide Inc. Method of Manufacturing Addressable and Static Electronic Displays
US20140021493A1 (en) * 2012-07-20 2014-01-23 Peter Andrews Solid state lighting component package with layer
KR20150094733A (en) * 2012-12-13 2015-08-19 픽스트로닉스 인코포레이티드 Display with light modulating pixels organized in off-axis arrangement
US20160043061A1 (en) * 2013-04-01 2016-02-11 Lg Electronics Inc. Display device using semiconductor light emitting device
WO2016057588A2 (en) * 2014-10-07 2016-04-14 Corning Incorporated Direct view display device and light unit for direct view display device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3446330A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111464803A (en) * 2020-04-16 2020-07-28 中国长城科技集团股份有限公司 Display control system

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