WO2022255504A1

WO2022255504A1 - Display device

Info

Publication number: WO2022255504A1
Application number: PCT/KR2021/006791
Authority: WO
Inventors: 김동현; 김양현; 류승호; 원종화; 장명훈; 신종곤; 우상원; 김진성; 백기문
Original assignee: 엘지전자 주식회사
Priority date: 2021-06-01
Filing date: 2021-06-01
Publication date: 2022-12-08

Abstract

A display device is disclosed. The display device comprises: a display panel; and a module cover having the display panel coupled thereto. The display panel may comprise: a flat panel substrate; an electrode pad formed on the substrate; a solder fixed onto the electrode pad; a light emitting device fixed to the solder and electrically connected to the electrode pad; and a cover layer forming the upper surface of the solder and comprising a black material.

Description

display device

The present disclosure relates to a display device.

As the information society develops, the demand for display devices is also increasing in various forms. Display), OLED (Organic Light Emitting Diode), Micro LED (Micro Light Emitting Diode), etc. are being researched and used.

Digital Signage is not only a general TV, but also a communication tool that can induce marketing, advertising, training effects, and customer experience of companies in public places such as airports, hotels, hospitals, and subway stations. It is a display device that provides specific information as well as a broadcast program.

Digital signage is a device such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), OLED (Organic Light Emitting Diode), Micro LED (Light Emitting Diode), etc. As a medium that displays various contents and commercial advertisements by installing display panels, it can be installed not only in homes but also in apartment elevators, in subway stations, in subways, in buses, universities, banks, convenience stores, discount stores, and shopping malls where the public moves. have.

Recently, as digital signage has become larger and larger, many studies have been conducted to improve the image quality of display panels.

The present disclosure aims to solve the foregoing and other problems.

An object of the present disclosure may be to provide a display device that improves light extraction efficiency of a display panel.

An object of the present disclosure may be to provide a display device that improves the image quality of a display panel.

According to one aspect of the present disclosure, a display device includes: a display panel; And, it includes a module cover to which the display panel is coupled, and the display panel includes: a flat substrate; an electrode pad formed on the substrate; a solder fixed on the electrode pad; a light emitting element fixed to the solder and electrically connected to the electrode pad; In addition, a cover layer forming an upper surface of the solder and including a black material may be included.

According to at least one embodiment of the present disclosure, a display device that improves light extraction efficiency of a display panel may be provided.

According to at least one embodiment of the present disclosure, a display device that improves the quality of a display panel may be provided.

Additional scope of applicability of the present disclosure will become apparent from the detailed description that follows. However, since various changes and modifications within the spirit and scope of the present disclosure can be clearly understood by those skilled in the art, it should be understood that the detailed description and specific examples such as preferred embodiments of the present disclosure are given as examples only.

1 to 3 are diagrams illustrating examples of display devices according to embodiments of the present disclosure.

4 is a diagram illustrating an example of a manufacturing process of a display panel included in a display device according to embodiments of the present disclosure.

5 to 11 are diagrams illustrating examples of a display panel included in a display device according to embodiments of the present disclosure.

Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings, but the same or similar elements are given the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted.

The suffixes "module" and "unit" for components used in the following description are given or used together in consideration of ease of writing the specification, and do not have meanings or roles that are distinct from each other by themselves. In addition, in describing the embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the embodiment disclosed in this specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in this specification, the technical idea disclosed in this specification is not limited by the accompanying drawings, and all changes included in the spirit and technical scope of the present disclosure , it should be understood to include equivalents or substitutes.

Terms including ordinal numbers, such as first and second, may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, terms such as "comprise" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Hereinafter, a micro LED will be described as an example for a display panel, but the display panel applicable to the present disclosure is not limited thereto.

1 and 2, the multi-display device 1000 includes a display module 100 capable of displaying images, a frame 200 supporting the display module 100, and the display module 100 and the frame 200. Mounted between them, it may include a displacement control unit (300, leveling unit) for adjusting their spacing. The displacement control unit 300 may be omitted.

The display module 100 may include a display panel 101 and a module cover 110 positioned behind the display panel 101 .

The display panel 101 may include a plurality of pixels R, G, and B. A plurality of pixels R, G, and B may be formed in each region where a plurality of data lines and a plurality of gate lines intersect. The plurality of pixels R, G, and B may be arranged or arranged in a matrix form.

For example, the plurality of pixels R, G, and B include a red ('R') sub-pixel, a green ('G') sub-pixel, and a blue ('B') sub-pixel. can include The plurality of pixels R, G, and B may further include a white ('W') sub-pixel.

The side of the display panel 101 that displays images may be referred to as the front or front side. When the display panel 101 displays an image, the side on which the image cannot be observed may be referred to as the rear or rear side. When viewing the display panel 101 from the front or front side, the upper side may be referred to as the upper side or upper side. Similarly, the lower side may be referred to as the lower side or the lower side. Similarly, the right side may be referred to as the right or right side, and the left side may be referred to as the left or left side.

The module cover 110 may be disposed behind the display panel 101 and the display panel 101 may be coupled thereto.

The display module 100 may include a first display module 100a to a sixth display module 100f. The first display module 100a to the sixth display module 100f may be arranged adjacent to each other in a vertical direction or a left-right direction.

For example, the first display module 100a may be disposed on the upper right side of the frame 200 . The second display module 100b may be disposed below the first display module 100a. The third display module 100c may be disposed below the second display module 100b. The fourth display module 100d may be disposed on the left side of the first display module 100a. The fifth display module 100e may be disposed below the fourth display module 100d and to the left of the second display module 100b. The sixth display module 100f may be disposed below the fifth display module 100e and to the left of the third display module 100c.

The frame 200 may be disposed behind the plurality of display modules 100 . The front of the frame 200 may face the rear of the display module 100 . The frame 200 may be disposed to correspond to the display module 100 in a thickness direction or a front-back direction of the display module 100 . The frame 200 may be formed in a picture frame shape with an open center area. The frame 200 may be formed to be long in vertical and horizontal directions so that a plurality of display modules 100 are mounted thereon. For example, the length of the upper side of the frame 200 may be substantially equal to the sum of the upper side of the first display module 100a and the upper side of the fourth display module 100d. Also, the length of the right side of the frame 200 may be substantially the same as the sum of the right side of the first display module 100a, the right side of the second display module 100b, and the right side of the third display module 100c. . It is not limited to this. The frame 200 may be longer or shorter than the display module 100 depending on external environments such as a building or a wall to be installed.

The frame 200 may have a thickness greater than that of the plurality of display modules 100 .

In Figures 1 and 2, it has been shown to be formed of one frame 200, but is not limited thereto. The frame 200 may include a first frame 200a to a sixth frame 200f. For example, the first frame 200a to the sixth frame 200f may be stacked or assembled in substantially the same manner as the first display module 100a to the sixth display module 100f described above. Accordingly, the n-th display module 100 may be mounted on the n-th frame 200 . Here, n may be a natural number.

The displacement control unit 300 may be disposed between the plurality of display modules 100 and the plurality of frames 200 . The displacement control unit 300 may be mounted on the frame 200 in the thickness direction of the display module 100 . The displacement control unit 300 mounted on the front of the frame 200 may be attached to the rear of the display module 100 . The displacement control unit 300 may adjust the separation distance between the rear surface of the display module 100 and the front surface of the frame 200 . The number of displacement control units 300 may be plural. The displacement control unit 300 may be disposed at each corner of the frame 200 . The displacement control unit 300 is disposed at each corner of the display module 100 and the frame 200 to adjust the separation distance between them.

Referring to FIG. 3 , the display panel 101 may include a substrate 1010 , electrode pads 1020 , and light emitting elements RGB. For example, the substrate 1010 may be a flat PCB, and the front surface of the substrate 1010 may be black. The electrode pad 1020 may be formed on the substrate 1010 . The number of electrode pads 1020 may be plural. The electrode pad 1020 may be formed of a conductive metal. The electrode pad 1020 may form a certain pattern on the substrate 1010 . For example, the electrode pad 1020 may have a W shape. The electrode pad 1020 may include a first part 1021 , a second part 1022 , a third part 1023 , and a connection part 1024 .

The light emitting device (RGB: 1040 see FIG. 4) may be an LED chip. A plurality of light emitting elements RGB may be mounted on the electrode pad 1020 . For example, the light emitting element RGB may be bonded on the electrode pad 1020 . The first light emitting device R may be mounted on the first part 1021, the second light emitting device G may be mounted on the second part 1022, and the third light emitting device B may be It may be mounted on the third part 1023. For example, the first light emitting device R may emit red light, the second light emitting device G may emit green light, and the third light emitting device B may emit blue light. For example, the light emitting element RGB may be an LED flip chip.

The electrode pads 1020 may be visually recognized on the front of the display panel 101 . While the electrode pads 1020 are visually recognized and the light emitting elements (RGB) are not switched on, the display panel 101 is misunderstood as displaying light information other than a black screen or the black color of the display panel 101 expression can be reduced.

In addition, while the light emitting element RGB is bonded to the electrode pad 1020, the light emitting element RGB may not be maintained horizontally or may be tilted. When the light emitting element RGB is tilted at the electrode pad 1020 and bonded, the irradiation angle of the light emitting element RGB may not be constant. That is, when the light emitting elements (RGB) are positioned tilted from the electrode pad 1020, a sense of heterogeneity can be given to the expression of natural colors on the front of the display panel 101, and the user can perceive that there is a difference in color. This may mean that the image quality of the display panel 101 is degraded.

Referring to FIG. 4 , an electrode pad 1020 may be formed on a substrate 1010 . For example, the electrode pad 1020 may be formed on the substrate 1010 by metal organic chemical deposition (MOCVD) or a printing technique. The connection part 1024 of the electrode pad 1020 may be spaced apart from the first part 1021 , the second part 1022 (see FIG. 3 ) and/or the third part 1023 (see FIG. 3 ).

Solder (S) may be printed on the electrode pad 1020 . The solder S may be an epoxy solder paste. The epoxy solder paste may be a mixture of epoxy binder and solder powder.

The solder S may include a black pigment. For example, the solder or solder paste may contain 96.5 percent tin (Sn), 3.0 percent silver (Ag), and 0.5 percent copper (Cu). For example, the black pigment may have a mass ratio of 3.8 to 6.3 percent relative to epoxy. For another example, the mass ratio of the black pigment to the total amount of solder powder may be 1 to 2.2 percent.

The light emitting device 1040 may be placed on the solder (S). While the light emitting device 1040 is placed on the solder S, the light emitting device 1040 may occupy a part of the space occupied by the solder S. As the light emitting element 1040 pushes the solder S, the light emitting element 1040 may contact the electrode pad 1020 . The solder S may cover the top surface of the electrode pad 1020 and the side surface of the light emitting device 1040 .

Heat may be applied while the light emitting element 1040 is placed on the electrode pad 1020 . At this time, separation may occur between the epoxy containing black paint and the solder (S) paste (or solder (S)). For example, the solder paste is melted and aggregated, and epoxy containing black paint may move to the upper surface of the solder S.

The optical layer 1030 may cover the light emitting device 1040 mounted on the substrate 1010 . For example, the optical layer 1030 may include silicon. The optical layer 1030 may package the substrate 1010 , the electrode pad 1020 , the solder S, and/or the light emitting device 1040 . Optical layer 1030 may be transparent.

Referring to FIG. 5 , the light emitting device 1040 may include a chip pad 1042 . The chip pad 1042 may be fixed to the lower surface of the light emitting element 1040 . The chip pad 1042 may include metal. The chip pad 1042 may be electrically connected to the light emitting element 1040 . The light emitting device 1040 may receive power through the chip pad 1042 . The chip pad 1042 may be plural. Each of the plurality of chip pads 1042 may be fixed on each electrode pad 1020 . The chip pad 1042 may be fixed to the electrode pad 1020 by solder (S). Solder S may form a thin film between the chip pad 1042 and the electrode pad 1020 to fix the chip pad 1042 to the electrode pad 1020 . The chip pad 1042 may be electrically connected to the electrode pad 1020 .

The solder S may include epoxy and solder paste. The solder S in which the solder paste is melted and hardened may cover the upper surface of the electrode pad 1020 , the side surface of the chip pad 1042 , and/or the side surface of the light emitting device 1040 . The solder S may fix the chip pad 1042 and/or the light emitting device 1040 on the electrode pad 1020 .

The solder S may include a first part Sa and a second part Sb. The first part Sa may be positioned between the chip pad 1042 and the electrode pad 1020 . The chip pad 1042 may be fixed on the electrode pad 1020 by the first part Sa. The second part Sb is positioned on the electrode pad 1020 and may contact the chip pad 1042 and side surfaces of the light emitting device 1040 . The second part Sb may contact the electrode pad 1020 and be fixed to the electrode pad 1020 . The second part (Sb) can strengthen the fastening force by which the light emitting element 1040 is fixed on the electrode pad 1020. The second part Sb may be connected to the first part Sa. The thickness ST of the first part Sa may be greater than the thickness CT of the chip pad 1042 .

The upper film (B) may cover the upper surface of the solder (S). The upper film (B) may be referred to as a cover layer (B). The upper film (B) may form an upper surface of the second part (Sb) of the solder (S). The upper film (B) may be an epoxy layer containing black paste. The upper film (B) may be black or gray. The upper film (B) may form an upper surface of the solder (S). The solder S may not be exposed to the outside by the upper layer B. For example, the substrate 1010 may be black, and the upper layer B may also be black. Accordingly, the solder S formed on the substrate 1010 may not be distinguished from the color of the substrate 1010 .

Referring to FIGS. 6 and 7 , solder S may be printed on the electrode pad 1020 . The upper film (B) may cover the electrode pad 1020 . The upper film (B) may form an upper surface of the solder (S). The area of the upper layer B may be 50% or more of the area of the electrode pad 1020 .

The light emitting device 1040 may be placed on the solder (S). While the light emitting device 1040 is placed on the solder S, the area of the solder S distributed on the electrode pad 1020 may increase. For example, the sum of the area of the light emitting device 1040 overlapping the electrode pad 1020 and the area of the upper layer B may be 70 to 80% of the area of the electrode pad 1020 .

Referring to FIG. 8 together with FIG. 6 , solder S may be printed on the electrode pad 1020 . The upper film (B) may cover the electrode pad 1020 . The upper film (B) may form an upper surface of the solder (S). The area of the upper layer B may be 50% or more of the area of the electrode pad 1020 .

The light emitting device 1040 may be placed on the solder (S). While the light emitting device 1040 is placed on the solder S, the area of the solder S distributed on the electrode pad 1020 may increase. For example, the sum of the area of the light emitting element 1040 overlapping the electrode pad 1020 and the area of the upper layer B may be 80 to 90% of the area of the electrode pad 1020 .

Referring to FIG. 9 together with FIG. 6 , an area of the electrode pad 1020 that is not overlapped by the light emitting element 1040 and exposed to the outside may be 130 to 150 percent of the area of the light emitting element 1040 . The area of the upper surface of the solder S may be larger than the area of the electrode pad 1020 exposed to the outside without being overlapped by the light emitting device 1040 . In this case, the area of the upper surface of the solder S may be 130 to 150 percent of the area of the light emitting device 1040 .

Solder S may be printed on the electrode pad 1020 . The upper film (B) may cover the electrode pad 1020 . The upper film (B) may form an upper surface of the solder (S). The area of the upper layer B may be 50% or more of the area of the electrode pad 1020 .

The light emitting device 1040 may be placed on the solder (S). While the light emitting device 1040 is placed on the solder S, the area of the solder S distributed on the electrode pad 1020 may increase. For example, the sum of the area of the light emitting element 1040 overlapping the electrode pad 1020 and the area of the upper layer B may be 90 to 100% of the area of the electrode pad 1020 .

Referring to FIGS. 10 and 11 , it can be seen that the upper surface of the solder S is identified from the substrate 1010 adjacent to both ends of the light emitting device RGB in FIG. 10 . Accordingly, the area of the black region of the substrate 1010 may be reduced. In FIG. 11 , it can be seen that the upper surface of the solder S is not identified from the substrate 1010 around the light emitting element RGB. Accordingly, it can be seen that the area of the substrate 1010 excluding the area of the light emitting element RGB is displayed as black. As the black area of the substrate 1010 increases in a state in which the light emitting elements RGB do not emit light and/or in a state in which the light emitting elements RGB emit light, black provided by the display panel 101 (see FIG. 3) The expressive power of color can be increased.

Referring to Figures 1 to 11, according to one aspect of the present disclosure, a display device includes: a display panel; And, it includes a module cover to which the display panel is coupled, and the display panel includes: a flat substrate; an electrode pad formed on the substrate; a solder fixed on the electrode pad; a light emitting element fixed to the solder and electrically connected to the electrode pad; In addition, a cover layer forming an upper surface of the solder and including a black material may be included.

According to another aspect of the present disclosure, the solder includes: a first part positioned between the electrode pad and the light emitting element; And, it may include a second part contacting the upper surface of the electrode pad and contacting the side surface of the light emitting element.

According to another aspect of the present disclosure, the cover layer may form an upper surface of the second part of the solder.

According to another aspect of the present disclosure, the second part of the solder may be connected to the first part.

According to another aspect of the present disclosure, the cover layer may be formed of an epoxy containing a black material.

According to another aspect of the present disclosure, the black material may have a mass ratio of 3.8 to 6.3 percent relative to the epoxy.

According to another aspect of the present disclosure, the mass ratio of the black material to the solder may be 1 to 2.2 percent.

According to another aspect of the present disclosure, an area of the cover layer may be 65 to 75 percent of an area of the light emitting device.

According to another aspect of the present disclosure, an area of the cover layer may be 90 to 100 percent of an area of the electrode pad that does not overlap with the light emitting device.

According to another aspect of the present disclosure, a chip pad positioned between the electrode pad and the light emitting element may be further included, and the thickness of the first part of the solder may be greater than that of the chip pad.

Certain or other embodiments of the present disclosure described above are not mutually exclusive or distinct from each other. Certain embodiments or other embodiments of the present disclosure described above may be combined or combined in their respective components or functions (Certain embodiments or other embodiments of the disclosure described above are not mutually exclusive or distinct from each other. Any or all elements of the embodiments of the disclosure described above may be combined or combined with each other in configuration or function).

For example, configuration A described in a specific embodiment and/or drawing may be combined with configuration B described in another embodiment and/or drawing. That is, even if the coupling between components is not directly described, it means that coupling is possible except for cases where coupling is impossible (For example, a configuration "A" described in one embodiment of the disclosure and the drawings). and a configuration "B" described in another embodiment of the disclosure and the drawings may be combined with each other. Namely, although the combination between the configurations is not directly described, the combination is possible except in the case where it is described that the combination is impossible).

The above detailed description should not be construed as limiting in all respects and should be considered illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention (although embodiments have been described with reference to a number of illustrative embodiments Its, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope of the principles of this disclosure.More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims.In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art).

Claims

display panel; and,

Including a module cover to which the display panel is coupled,

The display panel is:

substrate of flat plate;

an electrode pad formed on the substrate;

a solder fixed on the electrode pad;

a light emitting element fixed to the solder and electrically connected to the electrode pad; and,

A display device comprising a cover layer forming an upper surface of the solder and including a black material.
According to claim 1,

The solder is:

a first part positioned between the electrode pad and the light emitting element; and,

A display device comprising a second part contacting the upper surface of the electrode pad and contacting the side surface of the light emitting element.
According to claim 2,

The cover layer,

A display device forming an upper surface of the second part of the solder.
According to claim 2,

The second part of the solder is a display device connected to the first part.
According to claim 1,

The cover layer,

A display device formed of an epoxy containing a black material.
According to claim 5,

The black substance,

A display device with a mass ratio of 3.8 to 6.3 percent compared to the epoxy.
According to claim 5,

The black substance,

A display device having a mass ratio of 1 to 2.2 percent relative to the solder.
According to claim 1,

The area of the cover layer is 65 to 75 percent of the area of the light emitting element display device.
According to claim 1,

The area of the cover layer is 90 to 100 percent of the area of the electrode pad that does not overlap with the light emitting element.
According to claim 2,

Further comprising a chip pad positioned between the electrode pad and the light emitting element,

The thickness of the first part of the solder is greater than the thickness of the chip pad display device.