Light-emitting diode and display module comprising same

Abstract

A light-emitting diode and a display module comprising same are disclosed. The disclosed light-emitting diode comprises: a first semiconductor layer; a second semiconductor layer; an active layer provided between the first semiconductor layer and the second semiconductor layer so as to emit light; a first contact electrode electrically connected to the first semiconductor layer; a second contact electrode electrically connected to the second semiconductor layer; and a plurality of conductive members provided on the first contact electrode and the second contact electrode, wherein each of the plurality of conductive members includes a conductive adhesive member and a first protective layer that covers the conductive adhesive member.

Description

Light-emitting diode and display module including same

[0001] The present disclosure relates to a light emitting diode and a display module including the same.

[0002] A display panel includes a TFT substrate having a plurality of thin film transistors (TFTs) and a plurality of light-emitting diodes mounted on the substrate. The plurality of light-emitting diodes operate in pixel or sub-pixel units to display various colors. The operation of each pixel or sub-pixel is controlled by a plurality of TFTs. Each light-emitting diode emits a variety of colors, such as red, green, and blue. The plurality of light-emitting diodes can be transferred from a wafer or a relay substrate to the TFT substrate by a pick-and-place transfer method, a stamping transfer method, or a laser transfer method. The plurality of light-emitting diodes are electrically connected to substrate pads provided on the substrate using solder balls, anisotropic conductive films (ACFs), or conductive adhesives.

[0003] A light-emitting diode according to one or more embodiments may include: a first semiconductor layer; a second semiconductor layer; an active layer provided between the first semiconductor layer and the second semiconductor layer and configured to emit light; a first contact electrode electrically connected to the first semiconductor layer; a second contact electrode electrically connected to the second semiconductor layer; and a plurality of conductive members provided on the first contact electrode and the second contact electrode. Each of the plurality of conductive members may include: a conductive adhesive member; and a first protective layer covering the conductive adhesive member.

[0004] Each of the above plurality of challenge elements may further include a second protective layer covering the first protective layer.

[0005] A light emitting diode according to one or more embodiments may further include a barrier rib provided between the first contact electrode and the second contact electrode and including an insulating material.

[0006] The above plurality of conductive members can be arranged with a gap between each of the first contact electrode and the second contact electrode.

[0007] The above plurality of conductive members can be arranged in a certain pattern on each of the first contact electrode and the second contact electrode.

[0008] The above plurality of conductive members may have a polygonal shape, a circular shape, or an elliptical shape when the light-emitting diode is viewed from the bottom.

[0009] The above conductive adhesive member may have a curing temperature of less than 200°C.

[0010] The above conductive adhesive member may have a resistance value in the range of 0.1 ohm to 20 ohm after curing.

[0011] The conductive adhesive material may include an epoxy resin; and conductive materials dispersed at intervals in the epoxy resin. When the light-emitting diode is thermally compressed to a substrate, the conductive materials may contact or clump together at intervals that become narrower to conduct current between the first contact electrode and the first substrate pad of the substrate, and the second contact electrode and the substrate may conduct current between the second substrate pad.

[0012] The area of ​​each of the conductive adhesive members may be 1% to 30% of the area of ​​the smaller of the areas of the first contact electrode and the second contact electrode and the areas of the first substrate pad and the second substrate pad.

[0013] The above plurality of light-emitting diodes may be formed in a flip-chip form.

[0014] A method for manufacturing a light emitting diode according to one or more embodiments may include the steps of patterning a plurality of conductive adhesive members on first contact electrodes and second contact electrodes of a light emitting diode formed on a wafer; and forming a plurality of first protective layers to cover each of the plurality of conductive adhesive members.

[0015] A method for manufacturing a light emitting diode according to one or more embodiments may further include a step of forming a barrier layer comprising an insulating material between a first contact electrode and a second contact electrode of the light emitting diode.

[0016] A method for manufacturing a light emitting diode according to one or more embodiments may further include a step of forming a plurality of second protective layers to cover each of the plurality of first protective layers.

[0017] A display module according to one or more embodiments may include a substrate having a plurality of substrate pads arranged on one surface thereof; and a plurality of light-emitting diodes including a plurality of contact electrodes connected to the plurality of substrate pads. Each of the plurality of light-emitting diodes may include a conductive connecting member electrically and physically connecting the plurality of substrate pads and the plurality of contact electrodes; and a plurality of partition walls provided between the plurality of contact electrodes to insulate the plurality of contact electrodes.

[0018] FIG. 1 is a diagram illustrating a display module according to one or more embodiments.

[0019] FIG. 2 is a cross-sectional view illustrating a portion of a display module according to one or more embodiments.

[0020] FIG. 3 is a cross-sectional view illustrating a light emitting diode provided in a display module according to one or more embodiments.

[0021] FIG. 4 is a bottom view illustrating a light emitting diode provided in a display module according to one or more embodiments.

[0022] FIGS. 5A and 5B are drawings showing examples in which a conductive adhesive member provided in a light-emitting diode according to one or more embodiments is transformed from a non-conductive state to a conductive state by thermal compression.

[0023] Figures 6, 7, and 8 are bottom views illustrating light emitting diodes according to one or more embodiments.

[0024] FIG. 9 is a flowchart illustrating a manufacturing process of a light emitting diode according to one or more embodiments.

[0025] FIG. 10 is a drawing showing an example of a light emitting diode grown on a wafer according to one or more embodiments.

[0026] FIG. 11 is a drawing showing an example of patterning a conductive member on a contact electrode of a light-emitting diode according to one or more embodiments.

[0027] FIG. 12 is a drawing showing an example of irradiating UV (Ultraviolet) through an opening of a first mask onto a first PR (Photoresist) layer applied to a light-emitting diode according to one or more embodiments.

[0028] FIG. 13 is a drawing showing an example in which a portion of a first PR layer corresponding to a plurality of conductive adhesive members provided in a light-emitting diode according to one or more embodiments is cured.

[0029] FIG. 14 is a drawing showing an example in which a plurality of first protective layers are formed covering a plurality of conductive adhesive members provided in a light emitting diode according to one or more embodiments.

[0030] FIG. 15 is a drawing showing an example of irradiating UV through an opening of a second mask onto a second PR layer applied to a light-emitting diode according to one or more embodiments.

[0031] FIG. 16 is a drawing showing an example in which a portion of a second PR layer corresponding to a first protective layer provided in a light-emitting diode according to one or more embodiments is cured.

[0032] FIG. 17 is a drawing showing an example in which a second protective layer is formed covering a first protective layer provided to a light emitting diode according to one or more embodiments.

[0033] FIG. 18 is a drawing showing an example of irradiating UV through an opening of a third mask with a third PR layer applied to a light-emitting diode according to one or more embodiments.

[0034] FIG. 19 is a drawing showing an example in which a portion of a third PR layer corresponding to a first contact electrode and a second contact electrode of a light-emitting diode according to one or more embodiments is cured.

[0035] FIG. 20 is a drawing showing an example in which a partition is formed between a first contact electrode and a second contact electrode of a light-emitting diode according to one or more embodiments.

[0036] FIG. 21 is a flowchart illustrating a manufacturing process of a display module according to one or more embodiments.

[0037] FIG. 22 is a drawing showing an example in which a plurality of light-emitting diodes formed on a wafer according to one or more embodiments are provided with first contact electrodes and second contact electrodes, respectively.

[0038] FIG. 23 is an enlarged view illustrating in detail a light emitting diode according to one or more embodiments illustrated in FIG. 22.

[0039] FIG. 24 is a drawing illustrating an example of transferring a plurality of light emitting diodes from a wafer to a first carrier substrate according to one or more embodiments.

[0040] Figure 25 is a drawing showing an example of washing the first adhesive on the first carrier substrate.

[0041] FIG. 26 is an enlarged view illustrating in detail a light emitting diode according to one or more embodiments illustrated in FIG. 25.

[0042] FIG. 27 is a drawing illustrating an example of transferring a plurality of light-emitting diodes from a first carrier substrate to a second carrier substrate according to one or more embodiments.

[0043] Figure 28 is a drawing showing an example of washing a second adhesive on a second carrier substrate.

[0044] FIG. 29 is an enlarged view illustrating in detail a light emitting diode according to one or more embodiments illustrated in FIG. 28.

[0045] FIG. 30 is a drawing illustrating an example of transferring a plurality of light-emitting diodes from a second carrier substrate to a substrate according to one or more embodiments.

[0046] FIG. 31 is a drawing showing an example of thermally bonding a plurality of light emitting diodes to a substrate according to one or more embodiments.

[0047] FIG. 32 is a block diagram illustrating a display device according to one or more embodiments.

[0048] Hereinafter, various embodiments will be described in more detail with reference to the accompanying drawings. One or more embodiments described herein may be variously modified. Specific embodiments may be depicted in the drawings and further described in the detailed description. However, the specific embodiments disclosed in the accompanying drawings are merely intended to facilitate understanding of various embodiments. Therefore, the technical concepts disclosed in the accompanying drawings are not intended to be limited by the specific embodiments disclosed in the accompanying drawings, but should be understood to include all equivalents or alternatives falling within the spirit and technical scope of the present disclosure.

[0049] In this disclosure, terms including ordinal numbers such as "first," "second," etc. may be used to describe various components, but these components are not limited by the aforementioned terms. The aforementioned terms are used solely for the purpose of distinguishing one component from another. In this disclosure, terms such as "comprises" or "has" should be understood to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preemptively exclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to the other component, but that other components may also be present in between. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components present in between. In this disclosure, the term "same" may encompass not only complete matching but also differences that take into account the scope of processing errors. If a detailed description of a related known function or configuration is deemed likely to unnecessarily obscure the gist of this disclosure, the detailed description will be abbreviated or omitted.

[0050] Below, with reference to the attached drawings, an embodiment of the present disclosure is described in detail so that those skilled in the art can easily implement the present disclosure. However, the embodiment of the present disclosure may be implemented in various different forms and is not limited to the embodiment of the present disclosure described herein.

[0051] FIG. 1 is a drawing illustrating a display module according to one or more embodiments. FIG. 2 is a cross-sectional view illustrating a portion of a display module according to one or more embodiments.

[0052] A display device (1) according to one or more embodiments may include at least one display module (3). The display device (1) may include two or more display modules (3) to provide a large screen. In this case, the two or more display modules (3) may be connected in a horizontal direction and / or a vertical direction.

[0053] Referring to FIGS. 1 and 2, the display module (3) may include a substrate (30) and a plurality of light-emitting diodes (100, 200, 300) arranged on the substrate (30). The plurality of light-emitting diodes may include a first light-emitting diode (100) that emits light in a red wavelength band, a second light-emitting diode (200) that emits light in a green wavelength band, and a third light-emitting diode (300) that emits light in a blue wavelength band.

[0054] The substrate (30) may be provided with a plurality of pixel areas (30a) in a roughly grid shape. Each pixel area may be provided with one pixel. One pixel may be composed of a plurality of sub-pixels. A sub-pixel is a light-emitting diode.

[0055] A TFT layer (50) may be provided on the front surface of the substrate (30) on which a plurality of pixel areas (30a) are provided. A power supply circuit for supplying power to the TFT layer (50), a data driving driver, a gate driving driver, and a timing controller for controlling each driving driver may be provided on the back surface of the substrate (30).

[0056] The TFT layer (50) may include a plurality of TFTs for driving a plurality of light-emitting diodes (100, 200, 300). The TFT layer (50) may be integrally formed on the front surface of the substrate (30), but is not limited thereto, and may be manufactured in the form of a separate film and attached to the front surface of the substrate (30). A plurality of substrate pads (31, 32, 33, 34, 35, 36) disposed on the TFT layer (50) may be electrically connected to the TFT layer (50).

[0057] The plurality of TFTs included in the TFT layer (50) are not limited to a specific structure or type. For example, the TFT may be implemented as an LTPS TFT (Low-temperature polycrystalline silicon TFT), an oxide TFT, a Si TFT (poly silicon, a-silicon), an organic TFT, a graphene TFT, etc. The TFT layer may be applied to the substrate (30) by forming only a P-type (or N-type) MOSFET (metal oxide semiconductor field effect transistor) using a Si wafer in a CMOS (complementary metal oxide semiconductor) process.

[0058] A plurality of contact electrodes (101, 102, 201, 202, 301, 302) provided on each of a plurality of light-emitting diodes (100, 200, 300) and a plurality of substrate pads (31, 32, 33, 34, 35, 36) of a substrate (30) can be electrically and physically interconnected by a conductive adhesive member (410).

[0059] Each of the plurality of light emitting diodes (100, 200, 300) may include a partition wall (500). The partition wall (500) may insulate between the plurality of contact electrodes (101, 102, 201, 202, 301, 302) of the plurality of light emitting diodes (100, 200, 300) and between the plurality of substrate pads (31, 32, 33, 34, 35, 36) of the substrate (30). For example, the partition wall (500) may insulate the plurality of contact electrodes (101, 102, 201, 202, 301, 302) of the respective light emitting diodes (100, 200, 300) from each other and insulate the corresponding plurality of substrate pads (31, 32, 33, 34, 35, 36) from each other.

[0060] Each of the plurality of light-emitting diodes (100, 200, 300) may include a light-emitting surface (120a, 220a, 320a) from which light is emitted. The plurality of light-emitting diodes (100, 200, 300) may be formed in a flip chip form in which a plurality of contact electrodes (101, 102, 201, 202, 301, 302) are provided on the opposite side of the light-emitting surface (120a, 220a, 320a).

[0061] FIG. 3 is a cross-sectional view illustrating a light emitting diode provided in a display module according to one or more embodiments. FIG. 4 is a bottom view illustrating a light emitting diode provided in a display module according to one or more embodiments. FIGS. 5a and 5b are drawings illustrating examples in which a conductive adhesive member provided in a light emitting diode according to one or more embodiments is transformed from a non-conductive state to a conductive state by thermal compression.

[0062] Referring to FIG. 3, a light emitting diode (100) according to one or more embodiments may include a first semiconductor layer (110) and a second semiconductor layer (120) grown on a wafer (20, see FIG. 10), and an active layer (130) provided between the first semiconductor layer (110) and the second semiconductor layer (120).

[0063] The first semiconductor layer (110), the second semiconductor layer (120), and the active layer (130) can be formed using a method such as metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), or plasma-enhanced chemical vapor deposition (PECVD).

[0064] The first semiconductor layer (110) may include, for example, a p-type semiconductor layer. The p-type semiconductor layer may be selected from, for example, gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium nitride (InN), indium aluminum gallium nitride (InAlGaN), aluminum indium nitride (AlInN), etc., and may be doped with a p-type dopant such as magnesium (Mg), zinc (Zn), calcium (Ca), strontium (Sr), barium (Ba), etc.

[0065] The second semiconductor layer (120) may include, for example, an n-type semiconductor layer. The n-type semiconductor layer may be selected from, for example, gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium nitride (InN), indium aluminum gallium nitride (InAlGaN), aluminum indium nitride (AlInN), etc., and may be doped with an n-type dopant such as silicon (Si), germanium (Ge), or tin (Sn). The upper surface of the second semiconductor layer (120) may be a light-emitting surface (100a).

[0066] The light-emitting diode (100) is not limited to the configuration described above. For example, the light-emitting diode (100) may include a first semiconductor layer (110) that includes an n-type semiconductor layer and a second semiconductor layer (120) that includes a p-type semiconductor layer.

[0067] The active layer (130) is a region where electrons and holes recombine, and as the electrons and holes recombine, they transition to a lower energy level and can generate light having a corresponding wavelength. For example, the active layer (130) may include amorphous silicon or polycrystalline silicon. The active layer (130) is not limited thereto and may contain an organic semiconductor material, etc. The active layer (130) may be formed in a single quantum well (SQW) structure or a multi quantum well (MQW) structure.

[0068] A light emitting diode (100) according to one or more embodiments may include a first contact electrode (101) and a second contact electrode (102). The first contact electrode (101) may be an anode electrode electrically connected to the second semiconductor layer (120). The second contact electrode (102) may be a cathode electrode electrically connected to the first semiconductor layer (110).

[0069] A light emitting diode (100) according to one or more embodiments may include a plurality of conductive members (400) provided on a first contact electrode (101) and a second contact electrode (102), and a partition wall (500) provided between the first contact electrode (101) and the second contact electrode (102).

[0070] A plurality of conductive members (400) may be patterned in a grid shape on the bottom surface of the first contact electrode (101) and the bottom surface of the second contact electrode (102), as shown in FIG. 4. The 'bottom surfaces' of the first contact electrode (101) and the second contact electrode (102) may be surfaces that are connected to the first substrate pad (31) and the second substrate pad (31) provided on the substrate (30), respectively (see FIG. 2).

[0071] A plurality of conductive members (400) may have substantially the same structure. Accordingly, the following describes one conductive member (400).

[0072] The conductive member (400) may include a conductive adhesive member (410), a first protective layer (420), and a second protective layer (430).

[0073] The conductive adhesive member (410) according to one or more embodiments may have a curing temperature of less than 200°C in consideration of the heat resistance characteristic limit. The conductive adhesive member (410) may have a range of a resistance value (R) after curing of 0.1 ohm to 20 ohm. If the resistance value (R) after curing of the conductive adhesive member (410) is less than 0.1 ohm, the material dispersibility is not satisfied, and if the resistance value (R) after curing exceeds 20 ohm, current loss may occur, making it difficult to use the conductive adhesive member (410).

[0074] The conductive adhesive member (410) may include an epoxy resin (411) and conductive materials (413) dispersed in the epoxy resin (411), as shown in FIG. 5A. When the light-emitting diode (100) transferred to the target substrate () is thermally compressed and cured on the substrate (30), the epoxy resin (411) may electrically and physically connect the first substrate pad (31) and the second substrate pad (32) of the substrate (30) and the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100) to each other.

[0075] The conductive materials (413) may be materials with high conductivity. For example, the conductive materials (413) may be gold (Au), silver (Ag), carbon (C), copper (Cu), nickel (Ni), aluminum (Al), indium (In), or tin (Sn). The conductive materials (413) may be distributed and spaced apart from each other within the epoxy resin (411) so that they are mostly not in contact with each other, as shown in FIG. 5B. When the conductive materials (413) are pressed during thermal compression, the spacing between them may become narrow, causing them to come into contact or clump together, thereby enabling current to flow.

[0076] The area of ​​the conductive adhesive member (410) may be 1% to 30% of the area of ​​the smaller of the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100) and the first substrate pad (31) and the second substrate pad (32) of the substrate (30). If the area of ​​the conductive adhesive member (410) is less than 1%, it is difficult to expect smooth electrical connection between the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100) and the first substrate pad (31) and the second substrate pad (32) of the substrate (30). If it exceeds 30%, there may be restrictions in forming a plurality of conductive adhesive members (410) in a desired pattern on the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100).

[0077] A conductive adhesive member (410) according to one or more embodiments may include a flux containing a plurality of fine metal particles. For example, the conductive adhesive member (410) may have fine conductive particles arranged regularly or irregularly in an adhesive resin and a contact resin. The adhesive resin may be a thermoplastic material (e.g., styrene butadiene, polyvinyl butylene, etc.) or a thermosetting material (epoxy resin, polyurethane, acrylic resin). The adhesive resin may have a black color to absorb external light. The external light may be natural light or light emitted from lights arranged around the display panel. The fine conductive particles may include polymer particles and a conductive metal material (e.g., gold (Au), nickel (Ni), lead (Pd), etc.) coated on the surface of the polymer particles.

[0078] The first protective layer (420) may be formed to cover the conductive adhesive member (410) to protect the conductive adhesive member (410) during the descum process. The conductive adhesive member (410) may be covered by the first protective layer (420) and not be exposed to the outside. The descum process is an etching process that removes the second adhesive (821, see FIG. 27) applied to the second carrier substrate (820) and the first protective layer (420) using plasma.

[0079] A plurality of light emitting diodes (100, 200, 300) are transferred from a first carrier substrate (810) to a second carrier substrate (820) before cleaning the second carrier substrate (820). The first protective layer (420) can improve the conductive adhesive member (410) from being partially lost or completely separated from the first contact electrode (101, 201, 301) and the second contact electrode (102, 202, 302) of each light emitting diode (100, 200, 300) when the second carrier substrate (820) is cleaned by a descum process to remove the second adhesive (821) applied to the second carrier substrate (820). The second adhesive (821) can include PDMS (Polydimethylsiloxane).

[0080] The second protective layer (430) may cover the first protective layer (420) to protect the first protective layer (420) when the first carrier substrate (810) is washed by the descum process. The first protective layer (420) may be covered by the second protective layer (430) and may not be exposed to the outside.

[0081] A plurality of light emitting diodes (100, 200, 300) are transferred from a wafer (20) to a first carrier substrate (810) before cleaning the first carrier substrate (810). The second protective layer (430) can improve the first protective layer (420) and the conductive adhesive member (410) from being partially lost or completely separated from the first contact electrode (101, 201, 301) and the second contact electrode (102, 202, 302) of each light emitting diode (100, 200, 300) when cleaning the first carrier substrate (810) to remove the first adhesive (811, see FIG. 24) applied to the first carrier substrate (810). The first adhesive (811) can include PI (Polyimide) or NdBR (Ultra High-cis Polybutadiene Rubber).

[0082] The partition wall (500) may include an insulating material. The partition wall (500) may be provided between the first contact electrode (101) and the second contact electrode (102) to prevent or improve a short between the first contact electrode (101) and the second contact electrode (102). The partition wall (500) may be provided on one surface of the second semiconductor layer (120) on which the first contact electrode (101) and the second contact electrode (102) are arranged.

[0083] Figures 6, 7, and 8 are bottom views illustrating light emitting diodes according to one or more embodiments.

[0084] Referring to FIG. 6, a light-emitting diode (100-1) may have a partition wall (500-1) provided between a first contact electrode (101-1) and a second contact electrode (102-1). The conductive member (400-1) provided on the first contact electrode (101-1) and the second contact electrode (102-1) may be patterned in various shapes other than a grid shape depending on its size and shape.

[0085] Here, the shape of the conductive member (400-1) may be a shape that appears when the light-emitting diode (100-1) is viewed from the bottom. The shape of the conductive member (400-1) may be a square, as shown in FIG. 6. The shape of the conductive member (400-1) is not limited to a square and may be formed in various ways. For example, as shown in FIG. 7, the shape of the conductive member (400-2) may be formed in a circular (or oval) shape, and as shown in FIG. 8, the shape of the conductive member (400-3) may be formed in a hexagon (or triangle, pentagon, etc.).

[0086] Fig. 9 is a flowchart illustrating a process for manufacturing a light-emitting diode according to one or more embodiments. Figs. 10 to 20 are drawings illustrating a process for manufacturing a light-emitting diode according to one or more embodiments. A plurality of light-emitting diodes are formed on a wafer (20), and for convenience of explanation, the process for forming one light-emitting diode will be described below.

[0087] Referring to FIG. 10, a first semiconductor layer (110), a second semiconductor layer (120), and an active layer (130) are formed on a wafer (20) through an epitaxy process or the like, and a first contact electrode (101) and a second contact electrode (102) are formed on the second semiconductor layer (120) through a deposition process and an etching process, thereby forming a light-emitting diode (901 in FIG. 9).

[0088] Referring to FIG. 11, a plurality of conductive adhesive members (410) are patterned on the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100) (902 in FIG. 9).

[0089] A plurality of conductive adhesive members (410) can be formed on the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100) through the following process.

[0090] For example, a conductive adhesive (not shown) is deposited to a predetermined thickness on one surface (20a) of a wafer (20) on which a light-emitting diode (100) is formed so as to cover the light-emitting diode (100). A mask (not shown) is aligned on the upper side of the wafer (20). A plurality of openings formed in a predetermined pattern may be provided in the mask so that a plurality of conductive adhesive members (410) may be patterned. Ultraviolet (UV) is irradiated to the conductive adhesive through the plurality of openings of the mask. After the UV irradiation is completed, some areas of the conductive adhesive that do not require patterning (e.g., areas that do not correspond to the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100)) are removed by an etching process. Accordingly, a plurality of conductive adhesive members (410) can be patterned on the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100).

[0091] Referring to FIG. 12, a first PR (Photoresist) layer (610) is deposited to a predetermined thickness on one side (20a) of a wafer (20) to cover a light-emitting diode (100) and a plurality of conductive adhesive members (410).

[0092] A first mask (710) is aligned on the first PR layer (610). The first mask (710) may have a plurality of first openings (711) corresponding to the size of the first protective layer (420). The plurality of first openings (711) may be provided in the first mask (710) to correspond to a plurality of conductive adhesive members (410), respectively. The size of the first openings (711) may be larger than the size of the conductive adhesive members (410).

[0093] UV is irradiated to the first PR layer (610) through a plurality of first openings (711) of the first mask (710). Some areas (611) of the first PR layer (610) irradiated with UV are cured as shown in Fig. 13.

[0094] Referring to FIG. 14, the first PR layer (610) except for some hardened areas (611) of the first PR layer (610) is removed from the wafer (20) by an etching process. Accordingly, a plurality of first protective layers (420) covering a plurality of conductive adhesive members (410) can be formed on the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100) (903 in FIG. 9).

[0095] Referring to FIG. 15, a second PR layer (620) is deposited to a predetermined thickness on one side (20a) of a wafer (20) to cover a light emitting diode (100) and a plurality of first protective layers (420).

[0096] A second mask (720) is aligned on the second PR layer (620). The second mask (720) may have a plurality of second openings (721) corresponding to the size of the second protective layer (430). The plurality of second openings (721) may be provided in the second mask (720) to correspond to the plurality of first protective layers (420), respectively. The size of the second openings (721) may be larger than the size of the first protective layer (420).

[0097] UV is irradiated to the second PR layer (620) through a plurality of second openings (721) of the second mask (720). Some areas (621) of the second PR layer (620) irradiated with UV are cured as shown in Fig. 16.

[0098] Referring to FIG. 17, the second PR layer (620) is removed from the wafer (20) by an etching process, except for some hardened areas (621) in the second PR layer (620). Accordingly, a plurality of second protective layers (430) covering a plurality of first protective layers (420) can be formed on the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100) (904 in FIG. 9).

[0099] Referring to FIG. 18, a third PR layer (630) is deposited to a predetermined thickness on one side (20a) of a wafer (20) to cover a light emitting diode (100) and a plurality of second protective layers (430).

[0100] A third mask (730) is aligned on the third PR layer (630). A third opening (731) may be provided in the third mask (730) at a location where a partition wall (500) is to be formed. The third opening (731) may be located between the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100).

[0101] UV is irradiated to the third PR layer (630) through the third opening (731) of the third mask (730). A portion (631) of the UV-irradiated third PR layer (630) is cured as shown in Fig. 19.

[0102] Referring to FIG. 20, the third PR layer (630) except for a hardened portion (631) of the third PR layer (630) is removed from the wafer (20) by an etching process. Accordingly, a partition wall (500) can be formed between the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100) (905 in FIG. 9). The partition wall (500) can be formed on one surface of the second semiconductor layer (120).

[0103] The conductive adhesive member (410), the first protective layer (420), the second protective layer (430), and the partition wall (500) provided in the light-emitting diode according to one or more embodiments are not limited to the manufacturing process described above, and may be applied to preset positions by a silk screen application method, an inkjet method, or a dispensing method, and then subjected to a curing process. For example, the conductive adhesive member (410) may be applied to the first contact electrode (101) and the second contact electrode (102) of the light-emitting diode (100), and then UV may be irradiated to cure the conductive adhesive member (410). The first protective layer (420) may be applied to cover the conductive adhesive member (410), and then UV may be irradiated to cure the first protective layer (420). The second protective layer (430) may be applied to cover the first protective layer (420), and then UV may be irradiated to cure the second protective layer (430).

[0104] FIG. 21 is a flowchart illustrating a manufacturing process of a display module according to one or more embodiments. FIGS. 22 to 32 are drawings illustrating a manufacturing process of a display module according to one or more embodiments.

[0105] Referring to FIG. 22, a plurality of light-emitting diodes (first, second, and third light-emitting diodes (100, 200, 300)) can be grown and formed on a wafer (20). Each light-emitting diode can have a first contact electrode (101, 201, 301) and a second contact electrode (102, 202, 302) formed on the opposite surface of the light-emitting surface (120a, 220a, 320a), respectively.

[0106] Referring to Fig. 23, the first light-emitting diode (100) may have a plurality of conductive members (400) provided on the first contact electrode (101) and the second contact electrode (102), respectively. In this case, each conductive member (400) includes a conductive adhesive member (410), a first protective layer (420) covering the conductive adhesive member (410), and a second protective layer (430) covering the first protective layer (420). The second and third light-emitting diodes (200, 300) may include substantially the same configuration as the first light-emitting diode (100).

[0107] Referring to FIG. 24, a plurality of light emitting diodes (100, 200, 300) can be transferred from a wafer (20) to a first carrier substrate (810) (2101 of FIG. 21).

[0108] A plurality of light emitting diodes (100, 200, 300) can be transferred to a first carrier substrate (810) by a laser beam (L) irradiated onto a wafer (20). A first contact electrode (101, 201, 301) and a second contact electrode (102, 202, 302) of a plurality of light emitting diodes (100, 200, 300) can be attached to the first carrier substrate (810) by a first adhesive (811) applied to an upper surface of the first carrier substrate (810).

[0109] Referring to FIG. 25, the first adhesive (811) on the first carrier substrate (810) can be largely removed by a primary washing (e.g., a descum process) (2102 of FIG. 21).

[0110] The second protective layer (430) may be entirely removed from the first protective layer (420) as shown in FIG. 26 when the first carrier substrate (810) is washed. Alternatively, most of the second protective layer (430) may be removed from the first protective layer (420) except for a portion of the second protective layer (430) remaining around the first protective layer (420) when the first carrier substrate (810) is washed.

[0111] Referring to FIG. 27, a plurality of light emitting diodes (100, 200, 300, 100', 200', 300') can be transferred from a first carrier substrate (810) to a second carrier substrate (820) (2103 of FIG. 21).

[0112] A plurality of light emitting diodes (100, 200, 300, 100', 200', 300') can be transferred to a second carrier substrate (820) by a laser beam (L) focused on a first carrier substrate (810). Depending on the size of the spot of the laser beam (L) focused on the first carrier substrate (810), a certain number of light emitting diodes can be simultaneously transferred to the second carrier substrate (820) as shown in FIG. 27.

[0113] The light-emitting surfaces of a plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') can be attached to a second carrier substrate (820) by a second adhesive (821) applied to the upper surface of the second carrier substrate (820).

[0114] Referring to FIG. 28, the second adhesive (821) on the second carrier substrate (820) can be largely removed by a primary wash (e.g., a descum process) (2104 of FIG. 21).

[0115] When the second carrier substrate (820) is washed, the entire first protective layer (420) may be removed from the conductive adhesive member (410) as shown in FIG. 29. Alternatively, when the second carrier substrate (820) is washed, most of the first protective layer (420) except for a portion of the first protective layer (420) remaining around the conductive adhesive member (410) may be removed from the conductive adhesive member (410).

[0116] Referring to FIG. 30, a plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') can be transferred from a second carrier substrate (820) to a substrate (30) which is a target substrate (2105 of FIG. 21). The substrate (30) is included in a display module (3). A plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') can be transferred to the substrate (30) by a laser beam (L) irradiated onto the second carrier substrate (820).

[0117] The first contact electrodes and the second contact electrodes of the plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') may be mounted on the first substrate pads and the second substrate pads of the corresponding substrates (30). For example, as shown in FIG. 30, the first contact electrode (101) of the first light-emitting diode (100) may be mounted on the first substrate pad (31) of the substrate (30), and the second contact electrode (102) of the first light-emitting diode (100) may be mounted on the second substrate pad (32) of the substrate (30). The plurality of conductive adhesive members (410) may be positioned between the first contact electrodes (101) and the first substrate pads (31) and between the second contact electrodes (102) and the second substrate pads (32).

[0118] Referring to FIG. 31, a plurality of light emitting diodes (100, 200, 300, 100', 200', 300') can be thermally pressed onto a substrate (30) by a pressing member (840) (2106 of FIG. 21).

[0119] A plurality of conductive adhesive members (410) can be fused between first contact electrodes of a plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') and first substrate pads of a substrate (30) corresponding thereto, and between second contact electrodes of a plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') and second substrate pads of a substrate (30) corresponding thereto. Accordingly, the first contact electrodes of a plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') and the first substrate pads of a substrate (30) corresponding thereto can be electrically and physically connected to each other. The second contact electrodes of the plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') and the second substrate pads of the corresponding substrate (30) can be electrically and physically connected to each other.

[0120] When a plurality of conductive adhesive members (410) are thermally compressed by a pressure member (840) to form a plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') toward the substrate (30), the conductive materials (413) included in the plurality of conductive adhesive members (410) can come into contact or clump together with the gaps between them narrowing to enable current conduction (see FIG. 5b).

[0121] The partition wall (500) can be pressed in a thermocompression direction between the first contact electrode and the second contact electrode of the plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') by a plurality of conductive adhesive members (410). The partition wall (500) can prevent or improve the short circuit between the first contact electrode and the second contact electrode of the plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') by the conductive adhesive member (410) pressed during thermocompression.

[0122] A display module (3) according to one or more embodiments may include a plurality of conductive members (400) patterned on first contact electrodes and second contact electrodes of each light emitting diode (100, 200, 300, 100', 200', 300'). Each conductive member (400) may include a conductive adhesive member (410), a first protective layer (420) covering the plurality of conductive adhesive members (410) to prevent the conductive adhesive members (410) from being lost when the substrate (30) is washed, and a second protective layer (430) covering the first protective layer (420). The first protective layer (420) and the second protective layer (430) allow the conductive adhesive member (410) to be held on the first contact electrode and the second contact electrode of each light emitting diode (100, 200, 300, 100', 200', 300') until the plurality of light emitting diodes (100, 200, 300, 100', 200', 300') are formed on the wafer (20) and transferred to the substrate (30) through a plurality of processes.

[0123] A display module (3) according to one or more embodiments can be electrically and physically connected to a substrate (30) by a plurality of conductive adhesive members (410) provided on a plurality of light-emitting diodes (100, 200, 300, 100', 200', 300'). Accordingly, when manufacturing the display module (3), a process of coating a predetermined adhesive on the entire surface of the substrate (30) to electrically and physically connect a plurality of light-emitting diodes (100, 200, 300, 100', 200', 300') to the substrate (30) can be omitted, thereby reducing material costs.

[0124] Meanwhile, a method for manufacturing a display module according to one or more embodiments may include a step of transferring a plurality of light-emitting diodes of a substrate (30) to a first carrier substrate (810), and a step of transferring the light-emitting diodes from the first carrier substrate (810) to the substrate (30). In this case, since the conductive member (400) provided for each light-emitting diode may omit the second protective layer (430), the conductive member (400) may include a conductive adhesive member (410) and a first protective layer (420). In this regard, a method for manufacturing a light-emitting diode (100) may include a step of forming a partition wall (500) between a first contact electrode (101) and a second contact electrode (102) of the light-emitting diode (100) subsequent to a step of forming a first protective layer (420) covering the conductive adhesive member (410).

[0125] FIG. 32 is a block diagram illustrating a display device according to one or more embodiments.

[0126] Referring to FIG. 32, a display device (1) may include a display module (3) and a processor (4). The display module (3) may include a display driver integrated circuit (IC) (7) for controlling the driving of a substrate (30) and a plurality of light-emitting diodes (100, 200, 300) provided on the substrate (30).

[0127] The processor (4) may be implemented as a digital signal processor (DSP), a microprocessor, a graphics processing unit (GPU), an artificial intelligence (AI) processor, a neural processing unit (NPU), or a time controller (TCON) that processes a digital image signal. However, the present invention is not limited thereto, and may include one or more of a central processing unit (CPU), a micro controller unit (MCU), a micro processing unit (MPU), a controller, an application processor (AP), a communication processor (CP), or an ARM processor, or may be defined by the relevant terminology. In addition, the processor (4) may be implemented as a system on chip (SoC) or large scale integration (LSI) having a built-in processing algorithm, or may be implemented in the form of an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA).

[0128] The processor (4) can control hardware or software components connected to the processor (4) by running an operating system or application program, and can perform various data processing and calculations. In addition, the processor (4) can load commands or data received from at least one of the other components into volatile memory and process them, and store various data in non-volatile memory.

[0129] The display driver IC (7) may include an interface module (7a), a memory (7b) (e.g., a buffer memory), an image processing module (7c), or a mapping module (7d). The display driver IC (7) may receive, for example, image information including image data or an image control signal corresponding to a command for controlling the image data, from another component of the display device (1) through the interface module (7a). For example, according to one embodiment, the image information may be received from a processor (4) (e.g., a main processor (e.g., an application processor) or an auxiliary processor (e.g., a graphics processing unit) that operates independently of the function of the main processor).

[0130] The display driver IC (7) can communicate with the sensor module through the interface module (7a). In addition, the display driver IC (7) can store at least a part of the received image information in the memory (7b), for example, on a frame basis. The image processing module (7c) can, for example, perform preprocessing or postprocessing (e.g., resolution, brightness, or size adjustment) on at least a part of the image data based on at least the characteristics of the image data or the characteristics of the substrate (30). The mapping module (7d) can generate a voltage value or a current value corresponding to the image data preprocessed or postprocessed through the image processing module (7c). According to one embodiment, the generation of the voltage value or the current value can be performed based at least in part on, for example, the properties of the pixels of the substrate (30) (e.g., the arrangement of the pixels (RGB stripe or pentile structure), or the size of each subpixel). At least some pixels of the substrate (30) may be driven based at least in part on, for example, the voltage value or current value, so that visual information (e.g., text, an image, or an icon) corresponding to the image data may be displayed through the substrate (30).

[0131] The display driver IC (7) can transmit a driving signal (e.g., a driver driving signal, a gate driving signal, etc.) to the display based on image information received from the processor (4).

[0132] The display driver IC (7) can display an image based on an image signal received from the processor (4). For example, the display driver IC (7) can display an image by generating a driving signal for a plurality of sub-pixels based on the image signal received from the processor (4) and controlling the light emission of the plurality of sub-pixels based on the driving signal.

[0133] According to one or more embodiments, the display module (3) may further include a touch circuit. The touch circuit may include a touch sensor and a touch sensor IC for controlling the same. The touch sensor IC may control the touch sensor to detect, for example, a touch input or a hovering input with respect to a designated location of the substrate (30). For example, the touch sensor IC may detect the touch input or the hovering input by measuring a change in a signal (e.g., voltage, light quantity, resistance, or charge quantity) with respect to the designated location of the substrate (30). The touch sensor IC may provide information (e.g., location, area, pressure, or time) about the detected touch input or hovering input to the processor (4). According to one embodiment, at least a portion of the touch circuit (e.g., the touch sensor IC) may be included as a part of the display driver IC (7), the substrate (30), or another component (e.g., an auxiliary processor) disposed externally of the display module (3).

[0134] According to one or more embodiments, the pixel driving method of the display module (3) may be an AM (active matrix) driving method or a PM (passive matrix) driving method.

[0135] According to one or more embodiments, the display device (1) may include a display module (3). The display module (3) may display various images. Here, the images may include still images and / or moving images. The display module (3) may display various images, such as broadcast content, multimedia content, etc. In addition, the display module (3) may also display a user interface and icons.

[0136] According to one or more embodiments, the display module (3) can be installed and applied in a wearable device, a portable device, a handheld device, and various electronic products or battlefields requiring a display.

[0137] According to one or more embodiments, the display device (1) may include a plurality of display modules (3). The plurality of display modules (3) may be physically connected to implement a large display (e.g., a large format display). The large display may be a monitor for a personal computer, a high-resolution television, a signage (or digital signage), or an electronic display by connecting a plurality of display modules in a grid arrangement.

[0138] While the present disclosure has been illustrated and described above with reference to various examples, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. In light-emitting diodes, First semiconductor layer; Second semiconductor layer; An active layer that emits light and is provided between the first semiconductor layer and the second semiconductor layer; A first contact electrode electrically connected to the first semiconductor layer; a second contact electrode electrically connected to the second semiconductor layer; and A plurality of conductive members provided on the first contact electrode and the second contact electrode; Each of the above multiple challenge absences, a challenging adhesive; and A light emitting diode comprising a first protective layer covering the above-described challenging adhesive member.

2. In paragraph 1, Each of the above multiple challenge absences, A light emitting diode further comprising a second protective layer covering the first protective layer.

3. In paragraph 1, A light emitting diode further comprising a barrier rib provided between the first contact electrode and the second contact electrode and including an insulating material.

4. In paragraph 1, A light emitting diode in which the plurality of conductive elements are spaced apart from each of the first contact electrode and the second contact electrode.

5. In paragraph 1, A light emitting diode in which the plurality of conductive elements are arranged in a predetermined pattern on each of the first contact electrode and the second contact electrode.

6. In paragraph 1, The above-mentioned plurality of challenging elements are light-emitting diodes having a polygonal shape, a circular shape, or an elliptical shape when the light-emitting diode is viewed from the bottom.

7. In paragraph 1, The above challenging adhesive member is, A light emitting diode having a curing temperature of less than 200°C.

8. In paragraph 1, The above challenging adhesive member is, A light emitting diode having a resistance value in the range of 0.1 ohm to 20 ohm after curing.

9. In paragraph 1, The above challenging adhesive member is, Epoxy resin; and Containing conductive materials dispersed at intervals in the above epoxy resin; The above challenging materials are, A light emitting diode in which the gaps between the light emitting diodes become narrower when the light emitting diodes are thermally compressed to the substrate, so that the first contact electrode and the first substrate pad of the substrate are electrically connected, and the second contact electrode and the substrate are electrically connected to the second substrate pad.

10. In paragraph 9, The area of ​​each of the above challenging adhesive members is: A light emitting diode having an area of ​​1% to 30% of the smaller of the areas of the first contact electrode and the second contact electrode and the areas of the first substrate pad and the second substrate pad.

11. In paragraph 1, The above plurality of light emitting diodes are light emitting diodes formed in a flip chip form.

12. In a method for manufacturing a light-emitting diode, A step of patterning a plurality of conductive adhesive members on the first contact electrode and the second contact electrode of the light-emitting diode formed on the wafer; and A method for manufacturing a light-emitting diode, comprising: forming a plurality of first protective layers to cover each of the plurality of conductive adhesive members.

13. In paragraph 12, A method for manufacturing a light-emitting diode, further comprising: forming a barrier wall including an insulating material between the first contact electrode and the second contact electrode of the light-emitting diode.

14. In paragraph 12, A method for manufacturing a light-emitting diode, further comprising: forming a plurality of second protective layers so as to cover each of the plurality of first protective layers.

15. In the display module, A substrate having a plurality of substrate pads arranged on one side; and A plurality of light emitting diodes including a plurality of contact electrodes connected to the plurality of substrate pads; Each of the above multiple light emitting diodes, A conductive connecting member electrically and physically connecting the plurality of substrate pads and the plurality of contact electrodes; and A display module including a plurality of barrier walls provided between the plurality of contact electrodes and insulating the plurality of contact electrodes.

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