Display module and electronic device

Abstract

This display comprises: a circuit board including first driving electrodes and second driving electrodes; and light-emitting diodes (LEDs), wherein the LED can include: a semiconductor layer layered in the horizontal direction, which is parallel to the surface of the circuit board, the semiconductor layer including a n-type semiconductor layer, a light-emitting layer and a p-type semiconductor layer; a first pixel electrode in contact with the first driving electrode; and a second pixel electrode in contact with the second driving electrode.

Description

Display modules and electronic devices

[0001] The present disclosure relates to a display module and an electronic device, and more particularly, to a display module capable of increasing space efficiency and light efficiency and an electronic device including a display module.

[0002] Recently, the technology for light-emitting diodes (LEDs) based on compound semiconductors such as GaN, GaAs, and GaP has been developing rapidly, and interest in LED display devices that utilize panel configuration technology that directly mounts (transfers) LEDs that emit light in the R (red), G (green), and B (blue) wavelength bands onto a circuit board is growing.

[0003] In particular, miniaturization of LEDs is essential for high-quality image output from LED display devices. Therefore, significant development infrastructure is being invested to perfect ultra-small micro-LEDs measuring less than 100 micrometers. Furthermore, with the recent development of processes for precisely mounting ultra-small LEDs measuring tens of micrometers, optimized LED and module manufacturing technologies are now required.

[0004] As a conventional technology, there exists a technology that utilizes a flip-chip type LED, but it has been pointed out that the flip-chip type LED has a limitation in that it is difficult to effectively use the light emitted toward the bottom of the LED because a significant portion of the lower area of ​​the LED is covered by the pixel electrode.

[0005] Meanwhile, as a conventional technology, there exists a technology that uses a vertical type LED in which pixel electrodes are placed on the upper and lower portions of the LED, but this has limitations in that it requires the use of an upper connection layer such as ITO (Indium Tin Oxide) or a separate wire to connect the upper electrode of the LED to the circuit board, which leads to complexity in design and process, low space efficiency, and reduced light efficiency.

[0006] To overcome the limitations of the prior art as described above, a display module having high space efficiency and light efficiency, a method for manufacturing the display module, and an electronic device including the display module are provided.

[0007] According to an aspect of the present disclosure, a display includes a circuit board including a first driving electrode and a second driving electrode; and an LED (light-emitting diode), wherein the LED includes a semiconductor layer stacked in a horizontal direction parallel to a surface of the circuit board; the semiconductor layer includes an n-type semiconductor layer; a light-emitting layer; and a p-type semiconductor layer; a first pixel electrode in contact with the first driving electrode; and a second pixel electrode in contact with the second driving electrode.

[0008] The LED may further include a light-emitting surface parallel to a surface of the circuit board; and a reflective layer perpendicular to the light-emitting surface and disposed on at least two of the four sides of the LED.

[0009] The first pixel electrode and the second pixel electrode may be disposed on two first side surfaces that are parallel to the semiconductor layer among the four side surfaces, and the reflective layer may be disposed on two second side surfaces that are perpendicular to the semiconductor layer among the four side surfaces.

[0010] The above reflective layer can be disposed on the four side surfaces and the lower surface of the LED.

[0011] The LED may further include an insulating layer disposed on a lower surface of the LED.

[0012] The first pixel electrode and the second pixel electrode may be in contact with a portion of a lower region of the two first side surfaces.

[0013] The first pixel electrode and the second pixel electrode can be in contact with two vertices of a square corresponding to one of the two second side surfaces.

[0014] The area of ​​the upper surface of the LED corresponding to the light-emitting surface may be wider than the area of ​​the lower surface of the LED.

[0015] According to an aspect of the present disclosure, a light-emitting diode (LED) may include: a light-emitting surface; a light-emitting layer; a p-type semiconductor layer laminated on a first surface of the light-emitting layer in a direction parallel to the light-emitting surface; an n-type semiconductor layer laminated on a second surface opposite the first surface of the light-emitting layer in a direction parallel to the light-emitting surface; a first pixel electrode connected to the p-type semiconductor layer; and a second pixel electrode connected to the n-type semiconductor layer.

[0016] It may further include a reflective layer perpendicular to the light-emitting surface and disposed on at least two of the four sides of the LED.

[0017] The first pixel electrode and the second pixel electrode may be disposed on two first sides that are parallel to the light-emitting layer among the four sides, and the reflective layer may be disposed on two second sides that are perpendicular to the light-emitting layer among the four sides.

[0018] The above reflective layer can be disposed on the four side surfaces and the lower surface of the LED.

[0019] The LED may further include an insulating layer disposed on the lower surface.

[0020] The first pixel electrode and the second pixel electrode may be in contact with a portion of a lower region of the two first side surfaces.

[0021] The first pixel electrode and the second pixel electrode can be in contact with two vertices of a square corresponding to one of the two second side surfaces.

[0022] The area of ​​the upper surface of the LED corresponding to the light-emitting surface may be wider than the area of ​​the lower surface of the LED.

[0023] The above display may further include a plurality of LEDs.

[0024] According to one or more embodiments for achieving the above-described object, a method for manufacturing a display module may include a step of forming a plurality of light-emitting diodes (LEDs) on a wafer, each LED including a plurality of semiconductor layers, two pixel electrodes disposed on upper portions of the plurality of semiconductor layers and lower portions of the plurality of semiconductor layers, a step of disposing a plurality of protrusions included in an aligner between the plurality of LEDs, and a step of moving the aligner in a horizontal direction such that the plurality of LEDs are rotated 90 degrees on the wafer by the plurality of protrusions.

[0025] Meanwhile, the method may further include a step of forming a bump on each of the two pixel electrodes, a step of transferring the plurality of LEDs to a circuit board including a plurality of driving electrodes, and a step of connecting the plurality of driving electrodes and the two pixel electrodes using the bump.

[0026] Meanwhile, the method may further include a step of forming a plurality of reflective layers on at least some of the four surfaces perpendicular to the light-emitting surfaces of the plurality of LEDs and a step of forming a black matrix between the plurality of LEDs.

[0027] Meanwhile, the step of transferring the plurality of LEDs may include a step of transferring a red LED, a green LED, and a blue LED among the plurality of LEDs to a mother substrate to form one pixel, and a step of transferring the plurality of LEDs transferred to the mother substrate to the circuit board.

[0028] The above and other aspects, features and advantages of specific embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings.

[0029] FIG. 1 is a drawing showing a portion of a display module according to one or more embodiments of the present disclosure;

[0030] FIG. 2 is a drawing showing a portion of a display module according to one or more embodiments of the present disclosure;

[0031] FIG. 3 is a drawing illustrating an embodiment in which each of a plurality of LEDs according to one or more embodiments includes three reflective layers;

[0032] FIG. 4 is a drawing illustrating an embodiment in which each of a plurality of LEDs according to one or more embodiments includes three reflective layers;

[0033] FIG. 5 is a drawing illustrating an embodiment in which each of a plurality of LEDs according to one or more embodiments includes five reflective layers;

[0034] FIG. 6 is a drawing illustrating an embodiment in which each of a plurality of LEDs according to one or more embodiments includes five reflective layers;

[0035] FIG. 7 is a drawing illustrating an embodiment in which each of a plurality of LEDs according to one or more embodiments includes two reflective layers and three insulating layers;

[0036] FIG. 8 is a drawing illustrating an embodiment in which each of a plurality of LEDs according to one or more embodiments includes two reflective layers and three insulating layers;

[0037] FIG. 9 is a flowchart briefly illustrating some of the methods for manufacturing a display module according to one or more embodiments of the present disclosure;

[0038] FIG. 10 is a drawing for detailing some of the manufacturing methods of a display module according to one or more embodiments of the present disclosure;

[0039] FIG. 11 is a flowchart briefly illustrating another part of a method for manufacturing a display module according to one or more embodiments of the present disclosure;

[0040] FIG. 12 is a drawing for detailing another part of a method for manufacturing a display module according to one or more embodiments of the present disclosure, and

[0041] FIG. 13 is a drawing for explaining an electronic device including a display module according to the present disclosure.

[0042] The present embodiments may be modified and have various embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the scope to specific embodiments, but should be understood to encompass various modifications, equivalents, and / or alternatives of the embodiments of the present disclosure. In connection with the description of the drawings, similar reference numerals may be used for similar components.

[0043] In describing the present disclosure, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present disclosure, a detailed description thereof will be omitted.

[0044] Additionally, the following embodiments may be modified in various other forms, and the scope of the technical concepts of the present disclosure is not limited to the following embodiments. Rather, these embodiments are provided to further faithfully and completely convey the technical concepts of the present disclosure to those skilled in the art.

[0045] The terminology used in this disclosure is for the purpose of describing specific embodiments only and is not intended to limit the scope of the rights. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0046] In this disclosure, expressions such as “has,” “can have,” “includes,” or “may include” indicate the presence of a corresponding feature (e.g., a component such as a number, function, operation, or part), and do not exclude the presence of additional features.

[0047] In this disclosure, expressions such as “A or B,” “at least one of A and / or B,” or “one or more of A or / and B” can include all possible combinations of the listed items. For example, “A or B,” “at least one of A and B,” or “at least one of A or B” can all refer to (1) including at least one A, (2) including at least one B, or (3) including both at least one A and at least one B.

[0048] The expressions “first,” “second,” “first,” or “second,” etc., used in this disclosure can describe various components, regardless of order and / or importance, and are only used to distinguish one component from another, but do not limit the components.

[0049] When it is said that a component (e.g., a first component) is “(operatively or communicatively) coupled with / to” or “connected to” another component (e.g., a second component), it should be understood that said component may be directly coupled to said other component, or may be coupled via another component (e.g., a third component).

[0050] On the other hand, when it is said that a component (e.g., a first component) is "directly connected" or "directly connected" to another component (e.g., a second component), it can be understood that no other component (e.g., a third component) exists between said component and said other component.

[0051] The expression "configured to" as used in the present disclosure may be used interchangeably with, for example, "suitable for," "having the capacity to," "designed to," "adapted to," "made to," or "capable of." The term "configured to" may not necessarily mean only "specifically designed to" in terms of hardware.

[0052] Instead, in some contexts, the phrase "a device configured to" may mean that the device, in conjunction with other devices or components, is "capable of" performing A, B, and C. For example, the phrase "a processor configured (or set) to perform A, B, and C" may refer to a dedicated processor (e.g., an embedded processor) for performing those operations, or a general-purpose processor (e.g., a CPU or application processor) that can perform those operations by executing one or more software programs stored in a memory device.

[0053] In the embodiments, a 'module' or 'part' performs at least one function or operation, and may be implemented as hardware or software, or as a combination of hardware and software. Furthermore, a plurality of 'modules' or 'parts' may be integrated into at least one module and implemented as at least one processor, except for a 'module' or 'part' that needs to be implemented as a specific hardware.

[0054] In this specification, spatial relative terms such as “upper,” “lower,” “upper,” “lower,” “upper,” “lower,” “horizontal,” and “vertical” are used to easily describe the positional relationship of each component when viewed from a direction depicted in the drawings. Therefore, the spatial relative terms indicating the positional relationship of each component may be understood differently when viewed from a direction other than the direction depicted in the drawings.

[0055] Meanwhile, the various elements and areas in the drawings are schematically drawn. Therefore, the technical concept of the present invention is not limited by the relative sizes or spacing depicted in the attached drawings.

[0056] Hereinafter, with reference to the attached drawings, embodiments according to the present disclosure will be described in detail so that a person having ordinary knowledge in the technical field to which the present disclosure pertains can easily implement the present disclosure.

[0057] FIG. 1 is a drawing illustrating a portion of a display module (100) according to one or more embodiments of the present disclosure. FIG. 2 is a drawing illustrating a portion of a display module (100) according to one or more embodiments of the present disclosure.

[0058] Since FIGS. 1 and 2 differ only in the shape of the LED (120) (Light Emitting Diode) and the pixel electrode, the following description will refer to FIGS. 1 and 2 together. Hereinafter, the basic structure and operation of each component included in the display module (100) will be described first, and then various embodiments according to the present disclosure will be described with specific reference to FIGS. 1 and 2.

[0059] The 'display module (100) (display)' according to the present disclosure refers to a configuration (or device) capable of displaying an image. In particular, the display module (100) can be included in an electronic device (1000) and display an image. When the display module (100) is included in the electronic device (1000), the display module (100) can display an image under the control of a processor (300) included in the electronic device (1000). An electronic device (1000) including a display module (100) will be described with reference to FIG. 13, and various embodiments related to the display module (100) will be described below.

[0060] The display module (100) may refer to the entire display panel included in the electronic device (1000), and a plurality of display modules (100) may be combined to form a single display panel. That is, the display module (100) may not only be included in an electronic device (1000) of the same type as a digital TV, a monitor, a tablet PC, a smart phone, etc., but may also be included in an electronic device (1000) of the same type as a digital signage, a video wall, etc. However, there is no particular limitation on the type of electronic device (1000) to which the display module (100) according to the present disclosure is applied.

[0061] As illustrated in FIGS. 1 and 2, the display module (100) may include a circuit board (110) and a plurality of LEDs (120). Although FIGS. 1 and 2 illustrate the structure of a display module (100) including three LEDs (120), this is merely for the sake of simplicity of the drawing, and there is no particular limitation on the number of LEDs (120) included in the display module (100). For convenience of explanation, the plurality of LEDs (120) will be described first below.

[0062] 'A plurality of LEDs (120)' can emit light under the control of a circuit board (110). Specifically, the LED (120) refers to an element that emits light when voltage is applied in the forward direction, and the term 'LED (120)' can mean an 'LED (120) chip' in which a chip-scale packaging process for the LED (120) has been completed.

[0063] Referring to FIGS. 1 and 2, each of the plurality of LEDs (120) according to the present disclosure may include a plurality of semiconductor layers and two pixel electrodes (124, 125). In addition, the plurality of semiconductor layers may include an n-type semiconductor layer (122), a p-type semiconductor layer (121), and a light-emitting layer (123).

[0064] The n-type semiconductor layer (122) and the p-type semiconductor layer (121) can be implemented as a compound semiconductor of group III-V, group II-VI, etc. In particular, the n-type semiconductor layer (122) and the p-type semiconductor layer (121) can be implemented as a nitride semiconductor. For example, the n-type semiconductor layer (122) and the p-type semiconductor layer (121) can be an n-GaN semiconductor layer and a p-GaN semiconductor layer, respectively. However, the n-type semiconductor layer (122) and the p-type semiconductor layer (121) according to the present disclosure are not limited thereto, and can be formed of various materials according to various characteristics required for the LED (120).

[0065] The n-type semiconductor layer (122) is a semiconductor in which free electrons are used as carriers for transferring charges, and can be made by doping with an n-type dopant such as Si, Ge, Sn, or Te. In addition, the p-type semiconductor is a semiconductor in which holes are used as carriers for transferring charges, and can be made by doping with a p-type dopant such as Mg, Zn, Ca, or Ba.

[0066] The light-emitting layer (123), the n-type semiconductor layer (122), and the p-type semiconductor layer (121) may be composed of various semiconductors having band gaps corresponding to specific regions within the spectrum. For example, a red LED (120) having an optical wavelength of 600-750 nm may include one or more layers based on an AlInGaP-based semiconductor. In addition, a blue LED (120) and a green LED (120) having optical wavelengths of 450-490 nm and 500-570 nm, respectively, may include one or more layers based on an AlInGaN-based semiconductor.

[0067] The light-emitting layer (123) is located between the n-type semiconductor layer (122) and the p-type semiconductor layer (121), and is a layer where electrons, which are carriers of the n-type semiconductor layer (122), and holes, which are carriers of the p-type semiconductor layer (121), meet. When electrons and holes meet in the light-emitting layer (123), a potential barrier is formed as the electrons and holes recombine. And when the electrons and holes overcome the potential barrier and transition to a lower energy level depending on the applied voltage, light of a corresponding wavelength is emitted.

[0068] Here, the light-emitting layer (123) may have a multi-quantum well structure, but the present disclosure is not limited thereto, and the light-emitting layer (123) may have various structures such as a single quantum well or a quantum dot structure. When the light-emitting layer (123) is formed with a multi-quantum well structure, the well layer / barrier layer of the light-emitting layer (123) may be formed with a structure such as InGaN / GaN, InGaN / InGaN, or GaAs / AlGaAs, but the present disclosure is not limited to such structures. The number of quantum wells included in the light-emitting layer (123) is also not limited to a specific number.

[0069] The three LEDs (120) illustrated in FIGS. 1 and 2 each illustrate a red LED (120-1), a green LED (120-2), and a blue LED (120-3) included in one pixel. That is, the display module (100) can be divided into a plurality of pixels, and the red LED (120-1), the green LED (120-2), and the blue LED (120-3) can implement one pixel of the display module (100). However, there is no particular limitation on the number and arrangement method of the LEDs (120) per pixel according to the present disclosure.

[0070] The 'two pixel electrodes (124, 125)' refer to electrodes included in each of the plurality of LEDs (120) to connect the plurality of LEDs (120) to the circuit board (110). Specifically, the two pixel electrodes (124, 125) are connected to the plurality of driving electrodes (111, 112) of the circuit board (110), thereby connecting the plurality of LEDs (120) to the circuit board (110). In the present disclosure, the term 'pixel electrode' is a term to distinguish it from the driving electrode disposed on the circuit board (110), and may be replaced with terms such as 'pixel electrode pad'.

[0071] The two pixel electrodes (124, 125) may include a first pixel electrode (124) and a second pixel electrode (125). Here, the 'first pixel electrode (124)' refers to a pixel electrode connected to a p-type semiconductor layer (121) and a first driving electrode (111) of a circuit board (110), and the 'second pixel electrode (125)' refers to a pixel electrode connected to an n-type semiconductor layer (122) and a second driving electrode (112) and having an opposite polarity to the first pixel electrode (124).

[0072] In the above, it has been described that each of the plurality of LEDs (120) includes two pixel electrodes (124, 125), but this is only for convenience of explanation, and the number of pixel electrodes included in each of the plurality of LEDs (120) may be three or more.

[0073] The 'circuit board (110)' refers to a board including a driving circuit for driving a plurality of LEDs (120) and a plurality of driving electrodes (111, 112). The term 'circuit board (110)' may be replaced with a term such as 'driving board'. The plurality of LEDs (120) may be arranged on the circuit board (110) and electrically connected to the driving circuit. The driving of the display module (100) may be performed in an active matrix manner or a passive matrix manner, and the driving circuit may be designed according to the driving manner. The circuit board (110) may be one of a TFT substrate, a printed circuit board, and a glass substrate including metal wiring, but is not limited thereto.

[0074] The driving circuit may be connected to a plurality of driving electrodes (111, 112) and may include a plurality of circuit elements such as switching elements. The switching element is a semiconductor element capable of controlling the driving of a plurality of LED (120) elements included in the display module (100), and serves as a kind of switch for individual pixels of the display device. For example, a TFT may be used as the switching element.

[0075] 'A plurality of driving electrodes (111, 112)' refers to electrodes included in the circuit board (110) to connect a plurality of LEDs (120) to the circuit board (110). The plurality of driving electrodes (111, 112) may be formed on one surface of the circuit board (110) and connected to a driving circuit, and may be connected to two pixel electrodes (124, 125) included in the plurality of LEDs (120). That is, in the present disclosure, the term 'driving electrode' is a term for specifying an electrode included in the circuit board (110) to distinguish it from a pixel electrode included in the plurality of LEDs (120), and may be replaced with a term such as 'driving electrode pad'. Meanwhile, depending on the description method, the plurality of driving electrodes (111, 112) and the circuit board (110) may be distinguished as separate configurations, and the plurality of driving electrodes (111, 112) may be described as being formed on the circuit board (110).

[0076] The plurality of driving electrodes (111, 112) may include a plurality of first driving electrodes (111) and a plurality of second driving electrodes (112). Here, the 'first driving electrode (111)' refers to a driving electrode connected to the first pixel electrode (124), and the 'second driving electrode (112)' refers to a driving electrode connected to the second pixel electrode (125) and having an opposite polarity to the first driving electrode (111). For example, the first driving electrode (111) is an anode and the second driving electrode (112) is a cathode.

[0077] The plurality of first driving electrodes (111) and the plurality of second driving electrodes (112) may have opposite polarities. For example, the plurality of first driving electrodes (111) may be anodes and the plurality of second driving electrodes (112) may be cathodes. Conversely, the plurality of first driving electrodes (111) may be cathodes and the plurality of second driving electrodes (112) may be anodes.

[0078] Hereinafter, various embodiments according to the present disclosure will be described in more detail with reference to FIGS. 1 and 2.

[0079] As illustrated in FIGS. 1 and 2, the plurality of semiconductor layers may be arranged in a vertical direction with respect to the circuit board (110). Specifically, the plurality of semiconductor layers may not be arranged parallel to a plane corresponding to the circuit board (110), but may be arranged perpendicular to a plane corresponding to the circuit board (110). Since the light-emitting surfaces of the plurality of LEDs (120) are parallel to the plane corresponding to the circuit board (110), the plurality of semiconductor layers may also be arranged in a vertical direction with respect to the light-emitting surfaces of the plurality of LEDs (120). That the plurality of semiconductor layers are arranged in a vertical direction with respect to the circuit board (110) means that the n-type semiconductor layer (122), the light-emitting layer (123), and the p-type semiconductor layer (121) included in the plurality of semiconductor layers are all arranged in a vertical direction with respect to the circuit board (110). That is, the semiconductor layers may be stacked in a horizontal direction parallel to the surface of the circuit board and / or the light-emitting surface of the LED.

[0080] Meanwhile, in the present disclosure, the fact that the n-type semiconductor layer (122) and the p-type semiconductor layer (121) are arranged in a vertical direction with respect to the circuit board (110) means that the surfaces of the n-type semiconductor layer (122) and the p-type semiconductor layer (121), which are in contact with the light-emitting layer (123), are arranged in a vertical direction with respect to the circuit board (110). Accordingly, even when a plurality of LEDs (120) have a shape as shown in FIG. 2, the n-type semiconductor layer (122) and the p-type semiconductor layer (121) can be arranged in a vertical direction with respect to the circuit board (110).

[0081] The n-type semiconductor layer (122), the light-emitting layer (123), and the p-type semiconductor layer (121) can be connected to each other in a horizontal direction. Specifically, the fact that the n-type semiconductor layer (122), the light-emitting layer (123), and the p-type semiconductor layer (121) are all arranged in a vertical direction with respect to the circuit board (110) means that the n-type semiconductor layer (122), the light-emitting layer (123), and the p-type semiconductor layer (121) are arranged parallel to each other. In addition, the light-emitting layer (123) is arranged between the n-type semiconductor layer (122) and the p-type semiconductor layer (121), and the n-type semiconductor layer (122), the light-emitting layer (123), and the p-type semiconductor layer (121) can be connected to be in contact with each other.

[0082] Each of the two pixel electrodes (124, 125) may be arranged in opposite directions with respect to the light-emitting layer (123) so as to be connected to one of the plurality of driving electrodes (111, 112). Specifically, the first pixel electrode (124) may be arranged in a first direction with respect to the light-emitting layer (123) so as to be connected to the first driving electrode (111) while being connected to the p-type semiconductor layer (121). The second pixel electrode (125) may be arranged in a second direction, which is opposite to the first direction with respect to the light-emitting layer (123), so as to be connected to the second driving electrode (112) while being connected to the n-type semiconductor layer (122).

[0083] Each of the plurality of LEDs (120) may include an upper surface corresponding to a light-emitting surface and a lower surface corresponding to a surface in an opposite direction of the light-emitting surface. In addition, each of the plurality of LEDs (120) may include four surfaces surrounding the plurality of LEDs (120) and perpendicular to the light-emitting surfaces of the plurality of LEDs (120). The four surfaces perpendicular to the light-emitting surfaces of the plurality of LEDs (120) may include two 'first surfaces' parallel to the plurality of semiconductor layers and two 'second surfaces' perpendicular to the plurality of semiconductor layers.

[0084] Each of the two pixel electrodes (124, 125) may be arranged to contact a portion of the lower side of the first faces. More specifically, each of the two pixel electrodes (124, 125) may be arranged in an area including two vertices of a square corresponding to the side surfaces of the plurality of LEDs (120). As illustrated in FIGS. 1 and 2 , each of the two pixel electrodes (124, 125) may be arranged at a lower left side portion and a lower right side portion of each of the plurality of LEDs (120). In this way, the two pixel electrodes (124, 125) are arranged at corner areas of the lower areas of the plurality of LEDs (120), thereby connecting the plurality of semiconductor layers and the circuit board (110) without limiting the lower areas of the plurality of LEDs (120).

[0085] There is no particular limitation on the shape of the plurality of LEDs (120) according to the present disclosure.

[0086] For example, as illustrated in FIG. 1, each of the cross sections of the plurality of LEDs (120) may be rectangular, that is, the plurality of LEDs (120) may have a rectangular parallelepiped shape. In other words, the area of ​​the upper surface corresponding to the light-emitting surface of the plurality of LEDs (120) may be equal to the area of ​​the lower surface of the plurality of LEDs (120). When the plurality of LEDs (120) are implemented to have a rectangular parallelepiped shape as illustrated in FIG. 1, there is no need to perform a separate etching process for the plurality of LEDs (120), so the convenience of design and process can be significantly improved.

[0087] For another example, as illustrated in FIG. 2, the cross-section of each of the plurality of LEDs (120) may be an inverted trapezoid (a trapezoid in which the length of the upper side is longer than the length of the lower side), that is, the plurality of LEDs (120) may have the shape of a trapezoidal column. In other words, the area of ​​the upper surface corresponding to the light-emitting surface of the plurality of LEDs (120) may be wider than the area of ​​the lower surface of the plurality of LEDs (120). When the area of ​​the upper surface corresponding to the light-emitting surface of the plurality of LEDs (120) is implemented to be wider than the area of ​​the lower surface of the plurality of LEDs (120), as illustrated in FIG. 2, the light-emitting efficiency of the plurality of LEDs (120) may be further improved.

[0088] According to the embodiments described above with reference to FIGS. 1 and 2, the display module (100) can provide a display module (100) having high space efficiency and light efficiency.

[0089] In particular, the display module (100) can have high space efficiency and light efficiency because, unlike the conventional vertical type LED (120), there is no need to use an upper connection layer such as ITO or a separate wire to connect the upper electrode of the LED (120) to the circuit board (110), and further, it can have low power consumption and convenience in design and process. In addition, unlike the conventional flip-chip type LED (120), the display module (100) can minimize the lower area of ​​the LED (120) being covered by the pixel electrode, and therefore, the light emitted toward the lower portion of the LED (120) can be effectively used, and accordingly, the light efficiency can be further improved.

[0090] FIGS. 3 and 4 are drawings for explaining one or more embodiments in which each of the plurality of LEDs (120) includes three reflective layers (126). FIGS. 5 and 6 are drawings for explaining one or more embodiments in which each of the plurality of LEDs (120) includes five reflective layers (126). And FIGS. 7 and 8 are drawings for explaining one or more embodiments in which each of the plurality of LEDs (120) includes two reflective layers (126) and three insulating layers (127).

[0091] In FIGS. 3 to 8, only one LED (120) and a portion of a circuit board (110) connected to one LED (120) are illustrated, but this is only for convenience of illustration, and the present disclosure may also be applied to a display module (100) in which a plurality of one LED (120) illustrated in FIGS. 3 to 8 are arranged on the entire circuit board (110).

[0092] As described above, each of the plurality of LEDs (120) may include an upper surface corresponding to the light-emitting surface and a lower surface corresponding to a surface in an opposite direction of the light-emitting surface. In addition, each of the plurality of LEDs (120) may include four surfaces surrounding the plurality of LEDs (120) and perpendicular to the light-emitting surfaces of the plurality of LEDs (120). The four surfaces perpendicular to the light-emitting surfaces of the plurality of LEDs (120) may include two 'first surfaces' parallel to the plurality of semiconductor layers and two 'second surfaces' perpendicular to the plurality of semiconductor layers.

[0093] To illustrate the six faces of the plurality of LEDs (120), FIG. 4 illustrates the structure of FIG. 3 in a top view, FIG. 6 illustrates the structure of FIG. 5 in a top view, and FIG. 8 illustrates the structure of FIG. 7 in a top view.

[0094] As illustrated in FIGS. 3 to 8, the plurality of LEDs (120) may further include a reflective layer (126). In addition, the plurality of LEDs (120) may further include an insulating layer (127). In addition, it goes without saying that various configurations for improving the characteristics of the plurality of LEDs (120) may further be included in the plurality of LEDs (120).

[0095] The reflective layer (126) can serve to increase the light emission efficiency of the LED (120) by reflecting light emitted from the light emitting layer (123) of the LED (120) toward the light emitting surface of the LED (120). For example, the reflective layer (126) can be formed in a metal reflector or distributed-Bragg-reflector structure.

[0096] The insulating layer (127) can stabilize the device characteristics of a plurality of LEDs (120). In particular, the insulating layer (127) can stabilize the device characteristics of the LED (120) by preventing light emitted from the light-emitting layer (123) from being emitted outside the LED (120). For example, the insulating layer (127) can include a material having excellent electrical insulation characteristics, such as silicon dioxide (SiO2).

[0097] In one or more embodiments, each of the plurality of LEDs (120) may further include a plurality of reflective layers (126) surrounding each of the plurality of LEDs (120) and disposed on at least some of the four faces perpendicular to the light-emitting surfaces of the plurality of LEDs (120).

[0098] Specifically, the plurality of reflective layers (126) may be arranged on two first surfaces that are parallel to the plurality of semiconductor layers among the four surfaces that are perpendicular to the light-emitting surfaces of the plurality of LEDs (120). In this case, the reflective layers (126) or the insulating layers (127) may be arranged on two second surfaces that are perpendicular to the plurality of semiconductor layers among the four surfaces that are perpendicular to the light-emitting surfaces of the plurality of LEDs (120) and on the lower surfaces of the plurality of LEDs (120).

[0099] In particular, in order to improve luminous efficiency, it may be desirable to arrange a plurality of reflective layers (126) on two first surfaces parallel to the light-emitting layer (123). Therefore, in the description of the present disclosure, the expression 'a plurality of reflective layers (126)' is used on the premise that at least two reflective layers (126) are arranged, but this is not intended to exclude the case where each of the plurality of LEDs (120) includes only one reflective layer (126).

[0100] Meanwhile, instead of the reflective layer (126), the two pixel electrodes (124, 125) may be arranged on two first surfaces that are parallel to the plurality of semiconductor layers among the four surfaces that are perpendicular to the light-emitting surfaces of the plurality of LEDs (120). In other words, instead of a separate reflective layer (126), the two pixel electrodes (124, 125) may be arranged to cover the two first surfaces that are parallel to the plurality of semiconductor layers, thereby allowing the two pixel electrodes (124, 125) to also perform the function of the reflective layer (126). Therefore, in this case, the material of the two pixel electrodes (124, 125) needs to be selected as a material that has electrical properties and high reflectivity, such as aluminum (Al) or silver (Ag). Meanwhile, in this case, a reflective layer (126) or an insulating layer (127) may be placed on two second surfaces perpendicular to the plurality of semiconductor layers among the four surfaces perpendicular to the light-emitting surfaces of the plurality of LEDs (120) and on the lower surface of the plurality of LEDs (120).

[0101] Referring to the examples of FIGS. 3 and 4, two pixel electrodes (124, 125) may be disposed on two first surfaces that are parallel to the plurality of semiconductor layers among four surfaces that are perpendicular to the light-emitting surfaces of the plurality of LEDs (120). In addition, a plurality of reflective layers (126) may be disposed on two second surfaces that are perpendicular to the plurality of semiconductor layers among four surfaces that are perpendicular to the light-emitting surfaces of the plurality of LEDs (120) and on the lower surfaces of the plurality of LEDs (120).

[0102] Referring to the examples of FIGS. 5 and 6, the plurality of reflective layers (126) may be arranged on four surfaces perpendicular to the light-emitting surfaces of the plurality of LEDs (120) and on the lower surfaces of the plurality of LEDs (120). In other words, the plurality of reflective layers (126) may be arranged to surround all surfaces except the light-emitting surfaces of the plurality of LEDs (120).

[0103] Referring to the examples of FIGS. 7 and 8, the plurality of reflective layers (126) may be disposed on two first surfaces that are parallel to the plurality of semiconductor layers among the four surfaces that are perpendicular to the light-emitting surfaces of the plurality of LEDs (120). In addition, the insulating layer (127) may be disposed on two second surfaces that are perpendicular to the plurality of semiconductor layers among the four surfaces that are perpendicular to the light-emitting surfaces of the plurality of LEDs (120) and on the lower surfaces of the plurality of LEDs (120).

[0104] In addition to the embodiments exemplarily described above, two pixel electrodes (124, 125), a reflective layer (126) and an insulating layer (127) may be arranged in various ways on the side of each of the plurality of LEDs (120) except for the light-emitting surface, and it goes without saying that a configuration for increasing the light-emitting efficiency of the plurality of LEDs (120) may be included in the plurality of LEDs (120).

[0105] According to the embodiment described above with reference to FIGS. 3 to 8, even though the light-emitting layer (123) is arranged perpendicular to the light-emitting surface, the light-emitting efficiency of the plurality of LEDs (120) can be further improved by effectively using the pixel electrode, the reflective layer (126), and the insulating layer (127).

[0106] FIG. 9 is a flowchart briefly illustrating a part of a method for manufacturing a display module (100) according to one or more embodiments of the present disclosure, and FIG. 10 is a drawing for explaining in detail a part of a method for manufacturing a display module (100) according to one or more embodiments of the present disclosure.

[0107] As illustrated in FIG. 9, the method for manufacturing a display module (100) may include a step of forming a plurality of LEDs (120) on a wafer (S910). Image 1010 of FIG. 10 shows a state in which a plurality of LEDs (120) are formed on a wafer.

[0108] Specifically, the step of forming a plurality of LEDs (120) on a wafer may include a step of depositing a plurality of semiconductor layers on the wafer and a step of forming two pixel electrodes (124, 125). As illustrated in image 1010 of FIG. 10, the step of forming two pixel electrodes (124, 125) may be a step of forming two pixel electrodes (124, 125) on the upper right and lower right sides of the deposited semiconductor layer.

[0109] The step of forming a plurality of LEDs (120) on a wafer may further include a step of etching a portion of the plurality of LEDs (120). For example, the step of forming a plurality of LEDs (120) on a wafer may include a step of etching so that the cross-section of each of the plurality of LEDs (120) becomes an inverted trapezoid, as illustrated in FIG. 2. However, in the present disclosure, there is no particular limitation on the method of manufacturing the plurality of LEDs (120) themselves.

[0110] A method for manufacturing a display module (100) may include a step of arranging a plurality of protrusions included in an aligner between a plurality of LEDs (120) (S920). Here, the 'aligner' refers to a configuration including a plurality of protrusions for rotating a plurality of LEDs (120) by 90 degrees.

[0111] Specifically, the step of arranging a plurality of protrusions included in the aligner may include a step of moving the aligner to the left or right so that the plurality of protrusions included in the aligner face between the plurality of LEDs (120) and a step of moving the aligner upward or downward so that the uppermost ends of the plurality of protrusions are positioned higher than the lowermost ends of the plurality of LEDs (120).

[0112] Image 1020 of Fig. 10 illustrates a state in which a plurality of protrusions included in an aligner are arranged between a plurality of LEDs (120). As illustrated in image 1020 of Fig. 10, the spacing between the plurality of protrusions may correspond to the spacing between the plurality of LEDs (120). Meanwhile, as long as the rotation of the plurality of LEDs (120) can be smoothly performed in step S930 described below, there is no particular limitation on how far the plurality of protrusions may be moved upward.

[0113] For example, as illustrated in image 1020 of FIG. 10, the tops of the plurality of protrusions may be arranged at a height corresponding to the light-emitting layer (123) of the plurality of LEDs (120). As another example, the tops of the plurality of protrusions may be arranged at a height corresponding to the pixel electrode (124, 125) included in the plurality of LEDs (120) that is closer to the aligner.

[0114] The method for manufacturing a display module (100) may include a step of horizontally moving an aligner so that a plurality of LEDs (120) rotate 90 degrees on the wafer by a plurality of protrusions (S930). Image 1030 of FIG. 10 shows a state in which a plurality of LEDs (120) rotate while the aligner is moved horizontally, and image 1040 of FIG. 10 shows a result of the plurality of LEDs (120) rotating as the aligner is moved horizontally.

[0115] Specifically, when the aligner is moved horizontally while the plurality of protrusions are arranged between the plurality of LEDs (120), the plurality of LEDs (120) are rotated 90 degrees in the clockwise direction. Here, whether the horizontal direction in which the aligner is moved is leftward or rightward may be determined according to the transfer process described below. For example, even if the aligner is moved to the rightward direction opposite to that illustrated in FIG. 10 to rotate the plurality of LEDs (120) 90 degrees counterclockwise, the display module (100) described with reference to FIGS. 1 to 8 can be manufactured if a process of transferring to an intermediate substrate and then to a circuit substrate (110) is included.

[0116] According to the embodiments described above with reference to FIGS. 9 and 10, a plurality of LEDs (120) are manufactured by vertically stacking a plurality of semiconductor layers on a wafer and forming pixel electrodes one by one above and below the plurality of semiconductor layers, and then, by rotating the plurality of LEDs (120) by 90 degrees using an aligner, an arrangement relationship of the plurality of LEDs (120) for manufacturing a display module (100) according to the present disclosure can be formed.

[0117] FIG. 11 is a flowchart briefly illustrating another part of a method for manufacturing a display module (100) according to one or more embodiments of the present disclosure, and FIG. 12 is a drawing for explaining in detail another part of a method for manufacturing a display module (100) according to one or more embodiments of the present disclosure.

[0118] In the above, the manufacturing method and the rotation method of a plurality of LEDs (120) among the manufacturing methods of the display module (100) have been described with reference to FIGS. 9 and 10. FIGS. 11 and 12 are for explaining steps that can be performed after the steps described in FIGS. 9 and 10.

[0119] The method for manufacturing a display module (100) may include a step of forming a bump on each of a plurality of pixel electrodes (124, 125) (S1110). Image 1210 of FIG. 12 illustrates a state before forming a bump on each of a plurality of pixel electrodes (124, 125), and image 1220 of FIG. 12 illustrates a state after forming a bump on each of a plurality of pixel electrodes (124, 125).

[0120] Specifically, a 'bump' refers to a configuration for connecting a plurality of pixel electrodes (124, 125) and a driving electrode of a circuit board (110). Materials for the bump may include solder alloys, copper, etc., and may be formed using electroplating, etc. There are no special restrictions on the materials and formation methods of the bump.

[0121] A method for manufacturing a display module (100) may include a step of transferring a plurality of LEDs (120) onto a circuit board (110) including a plurality of driving electrodes (111, 112) (S1120). Image 1230 of FIG. 12 illustrates a process of transferring a plurality of LEDs (120) onto a circuit board (110).

[0122] The step of transferring a plurality of LEDs (120) onto a circuit board (110) may include a step of transferring the plurality of LEDs (120) onto at least one mother substrate and a step of transferring the plurality of LEDs (120) transferred onto the mother substrate onto the circuit board (110). Here, the mother substrate may include a catch agent (e.g., NDBR (N,N'-Di-n-butyl-1,4-phenylenediamine, PDMS (Polydimethylsiloxane), etc.) for capturing the plurality of LEDs (120).

[0123] The manufacturing method of the display module (100) may include a step of connecting a plurality of driving electrodes (111, 112) and a plurality of pixel electrodes (124, 125) so that they are in contact using bumps (S1130). Image 1240 of FIG. 12 shows a process of connecting a plurality of driving electrodes (111, 112) and a plurality of pixel electrodes (124, 125) in a state where a plurality of LEDs (120) are transferred to a circuit board (110).

[0124] Specifically, the step of connecting the plurality of driving electrodes (111, 112) and the plurality of pixel electrodes (124, 125) may include a reflow step of heating the circuit board (110) onto which the plurality of LEDs (120) are transferred using a reflow oven. When the circuit board (110) onto which the plurality of LEDs (120) are transferred is heated, the bumps melt, forming an electrical connection between the plurality of driving electrodes (111, 112) and the plurality of pixel electrodes. Afterwards, the bumps harden again, stabilizing the electrical connection.

[0125] The method for manufacturing a display module (100) may include a step of forming a plurality of reflective layers (126) on at least some of the four surfaces perpendicular to the light-emitting surfaces of the plurality of LEDs (120) (S1140). Image 1250 of FIG. 12 shows a state in which reflective layers (126) are formed on two first surfaces parallel to the plurality of semiconductor layers among the four surfaces perpendicular to the light-emitting surfaces of the plurality of LEDs (120).

[0126] Specifically, the plurality of reflective layers (126) may be formed during the manufacturing of the plurality of LEDs (120), but may also be formed after the manufacturing of the plurality of LEDs (120) and the transfer of the plurality of LEDs (120), as described with reference to FIGS. 11 and 12. FIG. 12 exemplarily illustrates that the reflective layers (126) are formed on two first surfaces that are parallel to the plurality of semiconductor layers among the four surfaces that are perpendicular to the light-emitting surfaces of the plurality of LEDs (120), but as described with reference to FIGS. 3 to 8, there is no particular limitation on the positions and numbers of the plurality of reflective layers (126).

[0127] The method for manufacturing a display module (100) may include a step of forming a black matrix (130) between a plurality of LEDs (120) (S1150). Image 1260 of FIG. 12 shows a state in which the space between the plurality of LEDs (120) is filled with a black matrix (130). The black matrix (130) can prevent interference of light between pixels or sub-pixels of the display module (100).

[0128] Although embodiments of a method for manufacturing a display module (100) have been described above with reference to FIGS. 9 to 12, the present disclosure is not limited thereto. That is, if a method for manufacturing a display module (100) described with reference to FIGS. 1 to 8 is possible, steps other than those described in FIGS. 9 to 12 may be added, and some of the steps described in FIGS. 9 to 12 may be omitted.

[0129] FIG. 13 is a drawing for explaining an electronic device including a display module according to the present disclosure.

[0130] As illustrated in FIG. 13, an electronic device according to the present disclosure may include a display module (100), a memory (200), and a processor (300). However, the configurations illustrated in FIG. 13 are merely exemplary, and in implementing the present disclosure, new configurations such as a communication unit, an input unit, or an output unit may be added, or some configurations may be omitted, in addition to the configuration illustrated in FIG. 13.

[0131] The display module (100) refers to a configuration capable of displaying an image, and may have a structure according to various embodiments described with reference to FIGS. 1 to 12 in particular. That is, the various embodiments described with reference to FIGS. 1 to 12 may also be applied to the display module (100) included in an electronic device.

[0132] The memory (200) may store at least one instruction for an electronic device. Furthermore, the memory (200) may store an operating system (OS) for operating the electronic device. Furthermore, the memory (200) may store various software programs or applications for operating the electronic device according to various embodiments of the present disclosure. Furthermore, the memory (200) may include semiconductor memory, such as flash memory, or magnetic storage media, such as a hard disk.

[0133] Specifically, the memory (200) may store various software modules for operating the electronic device according to various embodiments of the present disclosure, and the processor (300) may control the operation of the electronic device by executing the various software modules stored in the memory (200). That is, the memory (200) is accessed by the processor (300), and data reading / recording / modifying / deleting / updating, etc. may be performed by the processor (300).

[0134] Meanwhile, in the present disclosure, the term memory (200) may be used to mean memory (200), ROM, RAM in the processor (300), or a memory card mounted in an electronic device.

[0135] In one or more embodiments, the memory (200) may store image data and instructions for displaying an image on the display module (100) based on the image data. In addition, various information necessary within the scope of achieving the purpose of the present disclosure may be stored in the memory (200), and the information stored in the memory (200) may be updated as received from an external device or input by a user.

[0136] The processor (300) controls the overall operation of the electronic device. Specifically, the processor (300) is connected to the configuration of the electronic device including the display module (100) and the memory (200), and can control the overall operation of the electronic device by executing at least one instruction stored in the memory (200) as described above.

[0137] The processor (300) may be implemented in various ways. For example, the processor (300) may be implemented as at least one of an application-specific integrated circuit, an embedded processor, a microprocessor, hardware control logic, a hardware finite state machine, and a digital signal processor. Meanwhile, the term "processor" in the present disclosure may be used to encompass a CPU, a GPU, an MPU, and the like.

[0138] In one or more embodiments, the processor (300) may control the display module (100) to display an image based on image data stored in the memory (200). Specifically, the processor (300) may include at least one timing controller that controls the driving of a plurality of LEDs (120) and a panel driver that controls the driving of the display panel.

[0139] The timing controller can control the panel driver to control a plurality of LEDs (120). Specifically, the timing controller can adjust image data stored in the memory (200) into a signal required by the panel driver and transmit the adjusted signal to the panel driver, thereby allowing the panel driver to control the operation of the plurality of LEDs (120).

[0140] The panel driver can control the driving of a plurality of LEDs (120) based on a signal received from the timing control. For example, the panel driver can include a plurality of driving ICs and a plurality of pixel driving circuits. In addition, the plurality of driving ICs can control the light emission of a plurality of light-emitting elements of a plurality of LEDs (120) connected to each of the plurality of pixel driving circuits by driving the plurality of pixel driving circuits.

[0141] In one or more embodiments, the processor (300) may adjust control signals for driving a plurality of LEDs to suit the structure of the display module according to the embodiments described above with reference to FIGS. 1 to 8.

[0142] Each of the components (e.g., modules or programs) according to the various embodiments of the present disclosure as described above may be composed of a single or multiple entities, and some of the sub-components described above may be omitted, or other sub-components may be further included in the various embodiments. Alternatively or additionally, some components (e.g., modules or programs) may be integrated into a single entity, which may perform the same or similar functions as those performed by each of the respective components prior to integration.

[0143] According to various embodiments, operations performed by a module, program or other component may be executed sequentially, in parallel, iteratively or heuristically, or at least some operations may be executed in a different order, omitted, or other operations may be added.

[0144] Although the preferred embodiments of the present disclosure have been illustrated and described above, the present disclosure is not limited to the specific embodiments described above, and various modifications may be made by a person having ordinary skill in the art to which the present disclosure pertains without departing from the gist of the present disclosure as claimed in the claims, and such modifications should not be understood individually from the technical idea or prospect of the present disclosure.

Claims

1. In terms of display, A circuit board including a first driving electrode and a second driving electrode; and Includes LED (light-emitting diode); The above LED is, A semiconductor layer laminated in a horizontal direction parallel to the surface of the circuit board; The above semiconductor layer is, n-type semiconductor layer; luminescent layer; and Contains a p-type semiconductor layer, a first pixel electrode in contact with the first driving electrode; and A display comprising a second pixel electrode in contact with the second driving electrode.

2. In paragraph 1, The above LED is, a light-emitting surface parallel to the surface of the circuit board; and A display further comprising a reflective layer perpendicular to the light-emitting surface and disposed on at least two of the four sides of the LED.

3. In paragraph 2, The first pixel electrode and the second pixel electrode are arranged on two first side surfaces that are parallel to the semiconductor layer among the four side surfaces, A display in which the reflective layer is disposed on two second sides that are perpendicular to the semiconductor layer among the four sides.

4. In paragraph 2, A display wherein the reflective layer is disposed on the four sides and the lower surface of the LED.

5. In paragraph 2, A display wherein the LED further comprises an insulating layer disposed on a lower surface of the LED.

6. In paragraph 3, A display in which the first pixel electrode and the second pixel electrode are in contact with a portion of the lower area of ​​the two first side surfaces.

7. In paragraph 6, A display in which the first pixel electrode and the second pixel electrode are in contact with two vertices of a square corresponding to one of the two second sides.

8. In paragraph 1, A display in which the area of ​​the upper surface of the LED corresponding to the light-emitting surface is larger than the area of ​​the lower surface of the LED.

9. In LED (light-emitting diode), luminous surface; luminescent layer; A p-type semiconductor layer laminated on the first surface of the light-emitting layer in a direction parallel to the light-emitting surface; An n-type semiconductor layer laminated on a second surface opposite the first surface of the light-emitting layer in a direction parallel to the light-emitting surface; a first pixel electrode connected to the p-type semiconductor layer; and An LED including a second pixel electrode connected to the n-type semiconductor layer.

10. In paragraph 9, An LED further comprising a reflective layer perpendicular to the light-emitting surface and disposed on at least two of the four sides of the LED.

11. In paragraph 10, The first pixel electrode and the second pixel electrode are arranged on two first sides that are parallel to the light-emitting layer among the four sides, An LED in which the reflective layer is arranged on two second surfaces that are perpendicular to the light-emitting layer among the four surfaces.

12. In paragraph 10, The above reflective layer is an LED disposed on the four sides and the lower surface of the LED.

13. In paragraph 10, An LED further comprising an insulating layer disposed on the lower surface of the LED.

14. In paragraph 11, An LED in which the first pixel electrode and the second pixel electrode are in contact with a portion of the lower area of ​​the two first side surfaces.

15. In paragraph 14, An LED in which the first pixel electrode and the second pixel electrode are in contact with two vertices of a square corresponding to one of the two second sides.

Images