Display device and forming method thereof

Abstract

The invention provides a forming method of display equipment. The forming method comprises the following steps: providing a substrate, wherein a plurality of bonding pads are arranged on the substrate; forming an adhesive layer on the substrate and covering the plurality of bonding pads; forming a patterned bonding layer corresponding to the plurality of bonding pads by utilizing a photoetching process; the light emitting unit is bonded to at least the bonding pad via the patterned adhesive layer.

Description

[0001] This invention is a divisional application of the invention with the application number 202110906763.2, the application date of August 9, 2021, and the invention title of "Display Device and Method of Forming the Same". Technical Field

[0002] The present disclosure relates to a display device, and more particularly to a display device including light-emitting units. Background Art

[0003] With the development of digital technology, display devices have been widely used in various aspects of daily life. For example, they have been widely used in modern information devices such as televisions, laptop computers, computers, mobile phones (e.g., smart phones), and such display devices are continuously developing towards being lightweight, thin, short, small, and fashionable.

[0004] Among various types of display devices, light-emitting diode (LED) display devices are becoming increasingly popular due to their advantages such as high efficiency and long service life.

[0005] However, existing light-emitting diode display devices are not satisfactory in all aspects. Summary of the Invention

[0006] Some embodiments of the present disclosure provide a display device. The display device includes a substrate and light-emitting units disposed on the substrate. The light-emitting units include a first conductor layer and a second conductor layer that overlap each other, a first semiconductor layer disposed between the first conductor layer and the second conductor layer, a second semiconductor layer disposed between the first semiconductor layer and the first conductor layer, a quantum well structure disposed between the first semiconductor layer and the second semiconductor layer, a through hole penetrating through the first semiconductor layer and the quantum well structure, and a conductive material disposed in the through hole. The second conductor layer is electrically connected to the second semiconductor layer via the conductive material. In these embodiments, since the light-emitting units are provided with conductor layers on both the upper and lower sides, both the upper and lower sides of the light-emitting units can be used to connect to the substrate of the display device, thereby increasing the flexibility in the manufacturing process of forming the display device.

[0007] Some embodiments of the present disclosure provide a method of forming a display device. The method of forming a display device includes providing a substrate. A plurality of bonding pads are disposed on the substrate. The method of forming a display device also includes forming an adhesive layer on the substrate to cover these bonding pads, forming a patterned adhesive layer corresponding to these bonding pads by a photolithography process, and bonding a light-emitting unit to at least one bonding pad via the patterned adhesive layer. In these embodiments, since the patterned adhesive layer of the display device is formed by a photolithography process, the formed pattern can have a smaller size and can be applied to bonding small-sized light-emitting units to the substrate of the display device.

[0008] Some embodiments of the present disclosure provide a display device. The display device includes a substrate, a first light-emitting unit and a second light-emitting unit disposed on the substrate. The first light-emitting unit is adjacent to the second light-emitting unit. In a first direction, the first light-emitting unit has a length P1, and the first light-emitting unit and the second light-emitting unit have a spacing Z1. The display device also includes a first adhesive layer disposed between the substrate and the first light-emitting unit, and a second adhesive layer disposed between the substrate and the second light-emitting unit. In the first direction, the first adhesive layer and the second adhesive layer have a spacing Z3, where Z1, Z3, and P1 satisfy the following formula: 0 < Z3 < (Z1 + P1), and Z1, Z3, and P1 are all greater than 0 micrometers (μm). In these embodiments, by setting and adjusting the length P1 of the first light-emitting unit, the spacing Z1 between adjacent light-emitting units, and the spacing Z3 between adjacent adhesive layers to satisfy the following formula 0 < Z3 < (Z1 + P1), the problem of poor electrical connection between the light-emitting unit and the display device substrate caused by insufficient adhesion due to too small an adhesion area between the adhesive layer and the light-emitting unit can be reduced.

[0009] Embodiments will be described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present disclosure can be more fully understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, in accordance with standard industry practice, the features are not drawn to scale. In fact, for clarity, the dimensions of various features may be arbitrarily enlarged or reduced.

[0011] Figure 1A 、 1B 1C, 1D, 1F are a series of cross-sectional views illustrating a method of forming a light-emitting unit according to some embodiments of the present disclosure.

[0012] Figure 1E is a top view of a light-emitting unit illustrated according to some embodiments of the present disclosure.

[0013] Figure 1G is a cross-sectional view of a display device 10 illustrated according to some embodiments of the present disclosure.

[0014] Figure 1H is a cross-sectional view of a display device 10 illustrated according to some embodiments of the present disclosure.

[0015] Figure 2A and Figure 2B are a top view and a cross-sectional view of a display device 20 illustrated according to some embodiments of the present disclosure.

[0016] Figure 3A and Figure 3B are a top view and a cross-sectional view of a display device 30 illustrated according to some embodiments of the present disclosure.

[0017] Figure 4A and Figure 4B are top views and cross-sectional views of the display device 40 illustrated according to some embodiments of the present disclosure.

[0018] Figure 5A and Figure 5B are top views and cross-sectional views of the display device 50 illustrated according to some embodiments of the present disclosure.

[0019] Figure 6A 、 6B 6C, 6D, and 6E are a series of cross-sectional views illustrating a method of forming the display device 60 according to some embodiments of the present disclosure.

[0020] Figure 6F is a cross-sectional view of the display device 60' illustrated according to some embodiments of the present disclosure.

[0021] Figure 6G 、 6H are a top view and a cross-sectional view of the display device 60'' illustrated according to some embodiments of the present disclosure.

[0022] Figure 6I is a top view of the display device 60'' illustrated according to some embodiments of the present disclosure.

[0023] Figure 6J is a top view of the display device 60a illustrated according to some embodiments of the present disclosure.

[0024] Figure 6K is a top view of the display device 60a illustrated according to some embodiments of the present disclosure.

[0025] Figure 6L is a top view of the display device 60a illustrated according to some embodiments of the present disclosure.

[0026] Figure 6M is a top view of the display device 60a illustrated according to some embodiments of the present disclosure.

[0027] Figure 6N is a top view of the display device 60a illustrated according to some embodiments of the present disclosure.

[0028] Figure 7A 、 7B 7C, 7D are a series of cross-sectional views illustrating a method of forming the display device 70 according to some embodiments of the present disclosure.

[0029] Figure 8A 、 8B 8C, 8D are a series of cross-sectional views illustrating a method of forming the display device 80 according to some embodiments of the present disclosure.

[0030] Figure 9A , 9B , 9C, and 9D are a series of cross-sectional views showing a method of forming a display device 90 according to some embodiments of the present disclosure.

[0031] Symbol Explanation

[0032] 10, 20, 30, 40, 50, 60, 60’, 60”, 60a, 70, 80, 90 ~ display device

[0033] 100 ~ substrate

[0034] 102 ~ first semiconductor layer

[0035] 102a ~ first side of the first semiconductor layer

[0036] 102b ~ second side of the first semiconductor layer

[0037] 103 ~ light-emitting unit

[0038] 104 ~ quantum well structure

[0039] 106 ~ second semiconductor layer

[0040] 108a ~ first conductor layer

[0041] 110a ~ third conductor layer

[0042] 108b ~ second conductor layer

[0043] 110b ~ fourth conductor layer

[0044] 112a, 112b ~ protective layer

[0045] 114 ~ temporary substrate

[0046] 115 ~ second insulating layer

[0047] 116 ~ through hole

[0048] 116a ~ conductive material

[0049] 116b ~ first insulating layer

[0050] 118 ~ substrate

[0051] 120 ~ bonding pad

[0052] 600 ~ first substrate

[0053] 601 ~ gripping head

[0054] 602 ~ adhesive layer

[0055] 602a, 602b, 602c, 602d, 602e, 602f, 602g, 602h, 602i, 602j - Portion of the adhesive layer

[0056] 603 - Conductive particles

[0057] 604 - Light-emitting unit

[0058] 606 - Light-emitting body of the light-emitting unit

[0059] 608 - First conductor layer or second conductor layer

[0060] 610 - Third conductor layer or fourth conductor layer

[0061] 612 - Second substrate

[0062] 700 - Substrate

[0063] 704 - Adhesive layer

[0064] 704A - First pattern

[0065] 704a - Sub-pattern of the first pattern

[0066] 704B - Second pattern

[0067] 704b - Sub-pattern of the second pattern

[0068] 706 - Light-emitting unit

[0069] 708 - Light-emitting body of the light-emitting unit

[0070] 710 - First conductor layer or second conductor layer

[0071] 712 - Third conductor layer or fourth conductor layer

[0072] C1, C2, C3, C4 - Bonding pads

[0073] S1, S2, S3, S4 - Spacing

[0074] O1, O2, O3, O4 - Openings

[0075] d1 - Diameter of the conductive particles

[0076] d2 - Distance

[0077] R1, R2 - Current paths

[0078] W1, W2 - Widths

[0079] A - A, B - B - Section lines

[0080] Y - First direction

[0081] X to the second direction

[0082] F1, F2 - center line

[0083] M - misalignment

[0084] L1, L2, L3 - columns

[0085] P1, P2 - lengths of light - emitting units

[0086] Z1, Z2 - spacing between adjacent light - emitting units

[0087] Z3, Z4 - spacing between adjacent adhesive layers

[0088] V - pixel Detailed implementation manners

[0089] The following disclosure provides many different embodiments or examples for implementing different features of the present case. The following disclosure describes specific examples of each component and its arrangement manner to simplify the description. Of course, these specific examples are not used for limitation. For example, if the present disclosure describes that a first feature is formed on or above a second feature, it means that it may include an embodiment in which the above - mentioned first feature and the above - mentioned second feature are in direct contact, and may also include an embodiment in which additional features are formed between the above - mentioned first feature and the second feature, so that the above - mentioned first feature and the second feature may not be in direct contact.

[0090] In addition, the different examples disclosed below may reuse the same reference symbols and / or marks. These repetitions are for the purpose of simplification and clarity, and are not used to limit a specific relationship between the different embodiments and / or structures discussed.

[0091] Some embodiments of the present disclosure will be described below. Additional operations may be provided before, between, and / or after the steps described in these embodiments. Some of the described steps may be replaced or omitted in different embodiments. In addition, although several steps of the present disclosure are described in a specific order in the following text, these steps may also be performed in other reasonable orders.

[0092] [First Embodiment]

[0093] The light - emitting units of this embodiment are provided with conductor layers on both the upper and lower sides. Therefore, both the upper and lower sides can be used to connect the substrate of the display device, which can increase the flexibility in the process of forming the display device. For example, the above - mentioned conductor layer can be the electrode of the light - emitting unit, and the substrate of the display device can be a thin - film transistor substrate.

[0094] For example, when a gas or a liquid is used to transfer a light-emitting unit onto a substrate in a flowing or vibrating manner, the contact surface between the light-emitting unit and the substrate is randomly generated. If a light-emitting unit that conventionally forms a conductor layer only on one side is used, it is possible that there is no conductor layer on the side where the light-emitting unit contacts the substrate to electrically connect the light-emitting unit to the substrate, resulting in the light-emitting unit being unable to be driven and thus unable to emit light.

[0095] The following will be described in conjunction with Figures 1A - 1F an exemplary method for forming the light-emitting unit of this embodiment.

[0096] As Figure 1A shown, a substrate 100 is provided. In one embodiment, the substrate 100 can be an epitaxial substrate, such as a sapphire substrate. In some other embodiments, the substrate 100 can also include a silicon carbide (SiC) substrate, a silicon (Si) substrate, a magnesium aluminate (MgAl2O4) substrate, a magnesium oxide (MgO) substrate, a lithium metaaluminate (LiAlO2) substrate, a lithium gallate (LiGaO2) substrate, a gallium nitride (GaN) substrate, a gallium arsenide (GaAs) substrate, a gallium phosphide (GaP) substrate, a glass substrate, other suitable substrates, or a combination of the above, but the present disclosure is not limited thereto.

[0097] In some embodiments, the substrate 100 can include a buffer layer (not shown in the figure) to reduce defects caused by lattice mismatch between the substrate 100 and the semiconductor layer on the substrate 100. For example, the buffer layer can include aluminum nitride (AlN), aluminum gallium nitride (AlGaN), other suitable materials, or a combination of the above, but the present disclosure is not limited thereto.

[0098] Please continue to refer to Figure 1A , a light-emitting unit 103 can be formed on the substrate 100. For example, the light-emitting unit 103 can be a light-emitting diode (such as a blue light-emitting diode, a red light-emitting diode, or a green light-emitting diode). In some embodiments, as Figure 1A shown, the light-emitting unit 103 includes a first semiconductor layer 102 and a second semiconductor layer 106 stacked vertically, and a quantum well structure 104 disposed between the first semiconductor layer 102 and the second semiconductor layer 106.

[0099] For example, the first semiconductor layer 102, the quantum well structure 104, and the second semiconductor layer 106 can be sequentially formed on a substrate 100 (e.g., a sapphire substrate) via an epitaxial process, but the present disclosure is not limited thereto. For example, the above epitaxial process can include a molecular-beam epitaxy (MBE) process, a metalorganic chemical vapor deposition (MOCVD) process, a hydride vapor phase epitaxy (HVPE) process, other suitable epitaxial processes, or a combination of the above. In some embodiments, the first semiconductor layer 102, the second semiconductor layer 106, and the quantum well structure 104 can be formed by the same process, and the difference among the three lies in different dopants, and the doping concentrations of the three can also be different.

[0100] In some embodiments, the first semiconductor layer 102, the quantum well structure 104, and the second semiconductor layer 106 can be patterned using a suitable patterning process. For example, the above patterning process can include a photolithography process, an etching process, other suitable processes, or a combination of the above. In some embodiments, the above photolithography process can include resist coating, soft baking, exposure, post-exposure baking, developing, other suitable processes, or a combination of the above, and the above etching process can include wet etching, dry etching, other suitable processes, or a combination of the above.

[0101] For example, the first semiconductor layer 102, the second semiconductor layer 106, and the quantum well structure 104 may each include, for example, gallium nitride (GaN), aluminum gallium nitride (AlGaN), aluminum nitride (AlN), gallium arsenide (GaAs), gallium indium phosphide (GaInP), aluminum gallium arsenide (AlGaAs), indium phosphide (InP), indium aluminum arsenide (InAlAs), indium gallium arsenide (InGaAs), aluminum gallium indium phosphide (AlGaInP), other suitable group III-V semiconductor materials, or a combination of the foregoing. However, the present disclosure is not limited thereto. In some embodiments, the first semiconductor layer 102 and the second semiconductor layer 106 may be doped with dopants of opposite conductivity types. For example, the first semiconductor layer 102 and the second semiconductor layer 106 may be doped by means of ion implantation or in-situ doping. For example, in the present embodiment, the first semiconductor layer 102 is formed of n-type GaN doped with a dopant such as silicon or oxygen, the second semiconductor layer 106 is formed of p-type GaN doped with a dopant such as magnesium, and the quantum well structure 104 may include a stacked structure formed by alternately laminating InGaN and GaN, and may increase the recombination probability of electrons and holes within this stacked structure to improve the light emission efficiency.

[0102] Please continue to refer to Figure 1A , the light emitting unit 103 further includes a first conductor layer 108a and a third conductor layer 110a disposed on one side of the light emitting unit 103. Specifically, the first conductor layer 108a and the third conductor layer 110a may be disposed on the first side 102a of the first semiconductor layer 102. As Figure 1A shown, the first conductor layer 108a may be electrically connected to the second semiconductor layer 106, and the third conductor layer 110a may be electrically connected to the first semiconductor layer 102. In some embodiments, the first conductor layer 108a directly contacts the second semiconductor layer 106, and the third conductor layer 110a directly contacts the first semiconductor layer 102.

[0103] In some embodiments, the materials of the first conductor layer 108a and the third conductor layer 110a may include metallic materials, other suitable conductive materials, or combinations thereof, but the present disclosure is not limited thereto. The metallic materials may include, for example: copper, tungsten, silver, tin, nickel, chromium, titanium, lead, gold, bismuth, antimony, zinc, zirconium, magnesium, indium, tellurium, gallium, other suitable metallic materials, alloys thereof, or combinations thereof. In some other embodiments, the materials of the first conductor layer 108a and the third conductor layer 110a may be transparent conductive materials, which may include, for example: indium tin oxide (ITO), tin oxide (SnO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), antimony tin oxide (ATO), antimony zinc oxide (AZO), other suitable transparent conductive materials, or combinations thereof, but the present disclosure is not limited thereto.

[0104] In some embodiments, a metallic blanket layer or a blanket layer of a transparent conductive material (not shown in the figures) may be first formed on the first semiconductor layer 102 and the second semiconductor layer 106 by physical vapor deposition (such as evaporation or sputtering), electroplating, atomic layer deposition, other suitable methods, or combinations thereof, and then the metallic blanket layer or the blanket layer of the transparent conductive material is patterned using patterning processes such as lithography and etching processes to form the first conductor layer 108a and the third conductor layer 110a.

[0105] Please continue to refer to Figure 1A , in some embodiments, a protective layer 112a may be formed on the first semiconductor layer 102 according to design requirements. The protective layer 112a may at least partially fill the gap between the first conductor layer 108a and the third conductor layer 110a, thereby improving the reliability of the light-emitting unit 103. For example, the protective layer 112a may include organic materials (such as acrylic-based materials), inorganic materials (such as silicon oxide, silicon nitride), other suitable materials, or combinations thereof. In some embodiments, the protective layer 112a may include silicon-based materials, but the present disclosure is not limited thereto. In some embodiments, the protective layer 112a may be formed by spin coating, chemical vapor deposition (such as plasma-enhanced CVD (PECVD)), other suitable methods, or combinations thereof, but the present disclosure is not limited thereto.

[0106] Next, as Figure 1B shown, the substrate 100 and the light-emitting unit 103 are inverted, and the light-emitting unit 103 is bonded to the temporary substrate 114. As Figure 1BAs shown, the substrate 100 and the temporary substrate 114 are respectively disposed on opposite sides of the light-emitting unit 103. For example, the temporary substrate 114 may be formed of silicon, glass, polyimide, polyethylene terephthalate, other suitable materials, or a combination of the foregoing, but the present disclosure is not limited thereto. In some embodiments, the light-emitting unit 103 and the temporary substrate 114 may be joined via an adhesive layer (not shown in the figures). For example, the adhesive layer may include, for example, a thermosetting material and / or a photocuring material, but the present disclosure is not limited thereto.

[0107] Next, as Figure 1C shown, the substrate 100 is removed. In this embodiment, the substrate 100 is removed by a laser lift-off process. For example, the laser light source of the laser lift-off process may include an excimer laser, a pico laser, a femto laser, other suitable laser light sources, or a combination of the foregoing, but the present disclosure is not limited thereto. In some other embodiments, the substrate 100 may also be removed using mechanical peeling, a grinding process, an etching process, other suitable processes, or a combination of the foregoing, but the present disclosure is not limited thereto.

[0108] Next, as Figure 1D shown, a second insulating layer 115 is formed on the second side 102b of the first semiconductor layer 102. For example, the second insulating layer 115 may include an organic material (e.g., an acrylic-based material), an inorganic material (e.g., silicon oxide, silicon nitride), other suitable materials, or a combination of the foregoing, but the present disclosure is not limited thereto. In some embodiments, the second insulating layer 115 may be formed using spin coating, chemical vapor deposition (e.g., plasma-assisted chemical vapor deposition), screen printing, other suitable methods, or a combination of the foregoing, and the second insulating layer 115 is patterned by a photolithography process and an etching process. For example, the photolithography process and the etching process described herein may be similar to or the same as the photolithography process and the etching process described above.

[0109] Next, please continue to refer to Figure 1D , a via 116 is formed, and a first insulating layer 116b and a conductive material 116a are formed in the via 116, with the first insulating layer 116b between the via 116 and the conductive material 116a. In some embodiments, as Figure 1DAs shown, the through hole 116 penetrates through the second insulating layer 115, the first semiconductor layer 102, and the quantum well structure 104, and the conductive material 116a is electrically connected to the second semiconductor layer 106. For example, the conductive material 116a can directly contact the second semiconductor layer 106 or be electrically connected to the second semiconductor layer 106 through other conductive components.

[0110] As Figure 1D shown, in some embodiments, the first insulating layer 116b can be disposed around the sidewall of the conductive material 116a. In some embodiments, the first insulating layer 116b can be disposed between the hole wall of the through hole 116 and the conductive material 116a. Further, in some embodiments, as Figure 1D shown, the first insulating layer 116b is disposed around the sidewall of the conductive material 116a but still exposes the top surface and / or the bottom surface of the conductive material 116a. For example, the first insulating layer 116b can separate the conductive material 116a from the first semiconductor layer 102, and the first insulating layer 116b separates the conductive material 116a from the quantum well structure 104. In other words, the first insulating layer 116b can be disposed between the conductive material 116a and the first semiconductor layer 102, and the first insulating layer 116b is disposed between the conductive material 116a and the quantum well structure 104. For example, methods such as mechanical drilling, laser drilling, dry etching, wet etching, other suitable methods, or combinations of the above can be used to first form the through hole 116 that penetrates through the second insulating layer 115, the first semiconductor layer 102, and the quantum well structure 104. Then, an insulating layer can be formed on the hole wall and the bottom of the through hole 116 using processes such as atomic layer deposition process, chemical vapor deposition process, other suitable processes, or combinations of the above. Then, the insulating layer on the bottom of the through hole 116 is removed via an etching process, leaving the insulating layer on the hole wall of the through hole 116 as the first insulating layer 116b. For example, the first insulating layer 116b can include silicon oxide (SiO2), silicon nitride (SiNx), other suitable insulating materials, or combinations of the above. The above chemical vapor deposition process can, for example, include high-density plasma chemical vapor deposition process, low-pressure chemical vapor deposition process, or plasma-assisted chemical vapor deposition process. The above etching process can, for example, include anisotropic etching process, but the present disclosure is not limited thereto.

[0111] Next, copper, tungsten, silver, tin, nickel, chromium, titanium, lead, bismuth, antimony, zinc, zirconium, magnesium, indium, tellurium, gallium, their alloys, other suitable conductive materials, or a combination thereof may be deposited in the vias 116 by physical vapor deposition (such as evaporation or sputtering), electroplating, atomic layer deposition, other suitable methods, or a combination of the above to form the conductive material 116a. In some embodiments, a process such as chemical mechanical polishing or back etching may be performed after the step of depositing the above-mentioned conductive material to remove the excess conductive material outside the vias 116. In some embodiments, the conductive material 116a may include acid-resistant metals (such as copper, silver, gold, or platinum).

[0112] Next, as Figure 1E and Figure 1F shown, a second conductor layer 108b and a fourth conductor layer 110b are formed on the second side 102b of the first semiconductor layer 102 to form a light-emitting unit 103 with conductor layers on both sides. Specifically, Figure 1E is a top view of the process part of the method for forming the light-emitting unit of this embodiment, and Figure 1F is a cross-sectional view taken along the Figure 1E section line A-A. It should be noted that, for the sake of simplicity, the protective layer 112b is omitted in Figure 1E .

[0113] Generally speaking, the second conductor layer 108b and the fourth conductor layer 110b on the second side 102b of the first semiconductor layer 102 are functionally and / or positionally and / or dimensionally corresponding to the first conductor layer 108a and the third conductor layer 110a on the first side 102a of the first semiconductor layer 102. In some embodiments, the second conductor layer 108b may be electrically connected to the second semiconductor layer 106, and the fourth conductor layer 110b may be electrically connected to the first semiconductor layer 102. Further, in some embodiments, the second conductor layer 108b is electrically connected to the second semiconductor layer 106 through the conductive material 116a in the via 116, and the fourth conductor layer 110b directly contacts the first semiconductor layer 102.

[0114] In some embodiments, in the top view, the areas of the second conductor layer 108b and the fourth conductor layer 110b on the second side 102b of the first semiconductor layer 102 are each substantially equal to the areas of the first conductor layer 108a and the third conductor layer 110a on the first side 102a of the first semiconductor layer 102. In some embodiments, the second conductor layer 108b, the fourth conductor layer 110b on the second side 102b of the first semiconductor layer 102, and the first conductor layer 108a, the third conductor layer 110a on the first side 102a of the first semiconductor layer 102 are mirror-symmetrical.

[0115] It should be understood that although the light-emitting unit 103 formed in this embodiment includes three through-holes 116, the present disclosure is not limited thereto. In some other embodiments, other numbers (for example, 1 to 20) of through-holes 116 may be formed according to design requirements, and a first insulating layer 116b and a conductive material 116a may be formed in the above-mentioned through-holes 116. For example, in some embodiments, the light-emitting unit 103 may include one or two through-holes 116.

[0116] Figure 1G A partial cross-sectional view of the display device 10 is illustrated according to some embodiments of the present invention. As Figure 1G shown, the temporary substrate 114 in the display device 10 is removed, and the light-emitting unit 103 is disposed on the substrate 118. The display device 10 includes the light-emitting unit 103 including the through-holes 116 of the foregoing embodiment, and the above-mentioned light-emitting unit 103 is electrically connected to the substrate 118. For example, the substrate 118 may include one or more active components (not shown in the figure), such as transistors. For example, the substrate 118 may be a Thin-Film Transistor (TFT) substrate, but the present disclosure is not limited thereto. In some embodiments, a driving circuit (not shown in the figure) may be disposed on the substrate 118, and the light-emitting unit 103 may be disposed on the driving circuit and electrically connected to the driving circuit.

[0117] The above-mentioned one or more active components may be electrically connected to the light-emitting unit 103. In some embodiments, the above-mentioned one or more active components may control or adjust a driving signal (for example, a current signal) transmitted to the light-emitting unit 103 to adjust the brightness of the light-emitting unit 103. In some embodiments, multiple light-emitting units 103 may be electrically connected to different active components respectively. In other words, the driving signals transmitted to the multiple light-emitting units 103 may be separately controlled via their respective corresponding active components, so as to achieve the purpose of local dimming control.

[0118] As Figure 1G shown, at least one bonding pad 120 may be disposed on the substrate 118. In some embodiments, the first conductor layer 108a and the third conductor layer 110a of the light-emitting unit 103 or the second conductor layer 108b and the fourth conductor layer 110b of the light-emitting unit 103 are electrically connected to the substrate 118 via the bonding pad 120.

[0119] In some embodiments, a bonding process such as eutectic bonding may be performed to bond the first conductor layer 108a and the third conductor layer 110a of the light-emitting unit 103 or the second conductor layer 108b and the fourth conductor layer 110b of the light-emitting unit 103 to the bonding pad 120.

[0120] In some embodiments, the first conductor layer 108a of the light-emitting unit 103 and the third conductor layer 110a, or the second conductor layer 108b of the light-emitting unit 103 and the fourth conductor layer 110b, may be joined to the bonding pad 120 via an adhesive layer (not shown in the figures) such as an anisotropic conductive film (ACF). For example, the above-mentioned anisotropic conductive film may include a plurality of conductive particles therein. In some embodiments, the above-mentioned conductive particles include a core portion formed of a polymer and a metal or metal alloy shell coated on the above-mentioned core portion.

[0121] As Figure 1G shown, when the first conductor layer 108a on the first side 102a of the first semiconductor layer 102 of the light-emitting unit 103 is electrically connected to the bonding pad 120 with the third conductor layer 110a (e.g., Figure 1G the right light-emitting unit 103), the current can flow through the first conductor layer 108a, the second semiconductor layer 106, the quantum well structure 104, the first semiconductor layer 102, and the third conductor layer 110a via the path R1, and the light-emitting unit 103 can achieve the function of emitting light.

[0122] Please continue to refer to Figure 1G and when the second conductor layer 108b on the second side 102b of the first semiconductor layer 102 of the light-emitting unit 103 is electrically connected to the bonding pad 120 with the fourth conductor layer 110b (e.g., Figure 1G the left light-emitting unit 103), the current can flow through the second conductor layer 108b, the conductive material 116a in the via hole 116, the second semiconductor layer 106, the quantum well structure 104, the first semiconductor layer 102, and the fourth conductor layer 110b via the path R2, and the light-emitting unit 103 can achieve the function of emitting light.

[0123] In some embodiments, since the second insulating layer 115 is disposed between the first semiconductor layer 102 and the second conductor layer 108b of the light-emitting unit 103, it can be ensured that the current can flow through the second semiconductor layer 106 and the quantum well structure 104 via the conductive material 116a in the via hole 116, and will not directly flow from the second conductor layer 108b to the fourth conductor layer 110b through the first semiconductor layer 102. In some embodiments, the first insulating layer 116b can separate the conductive material 116a from the first semiconductor layer 102 and separate the conductive material 116a from the quantum well structure 104, so that it can be ensured that the current can flow through the second semiconductor layer 106.

[0124] In some embodiments, the first conductor layer 108a and the third conductor layer 110a that are not joined to the substrate 118 (or the second conductor layer 108b and the fourth conductor layer 110b) are formed of a transparent conductive material, so that the influence on the light emission of the light-emitting unit 103 in the display device 10 can be reduced. For example, the transparent conductive material may include, for example, indium tin oxide (ITO), tin oxide (SnO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), antimony tin oxide (ATO), antimony zinc oxide (AZO) and other transparent conductive materials, but the present disclosure is not limited thereto. For example, Figure 1G the first conductor layer 108a and the third conductor layer 110a on the first side 102a of the first semiconductor layer 102 of the light-emitting unit 103 on the left side in Figure 1G and the second conductor layer 108b and the fourth conductor layer 110b on the second side 102b of the first semiconductor layer 102 of the light-emitting unit 103 on the right side in are formed of a transparent conductive material, so that no additional steps are required to remove them, and the effects of reducing the manufacturing process steps of the display device 10 and shortening the working hours can be achieved.

[0125] In some other embodiments, the first conductor layer 108a and the third conductor layer 110a that are not joined to the substrate 118 (or the second conductor layer 108b and the fourth conductor layer 110b) are formed of an opaque conductive material (for example, including metal materials such as copper, tungsten, silver, tin, nickel, chromium, titanium, lead, gold, bismuth, antimony, zinc, zirconium, magnesium, indium, tellurium or gallium). If the first conductor layer 108a and the third conductor layer 110a that are not joined to the substrate 118 (or the second conductor layer 108b and the fourth conductor layer 110b) are left in the display device 10, it may cause the light-emitting unit 103 to not emit light normally. Therefore, in these embodiments, processes such as etching and / or polishing can be performed to remove the first conductor layer 108a and the third conductor layer 110a that are not joined to the substrate 118 (or the second conductor layer 108b and the fourth conductor layer 110b). In other words, the first conductor layer 108a and the third conductor layer 110a that are not joined to the substrate 118 (or the second conductor layer 108b and the fourth conductor layer 110b) will not be left in the final display device 10. For example, the Figure 1G second conductor layer 108b and the fourth conductor layer 110b on the second side 102b of the first semiconductor layer 102 of the light-emitting unit 103 on the right side in and Figure 1G the first conductor layer 108a and the third conductor layer 110a on the first side 102a of the first semiconductor layer 102 of the light-emitting unit 103 on the left side in can be removed, and the display device 10 as shown in Figure 1H can be obtained.

[0126] In some embodiments, in order to reduce the damage to the conductive material 116a in the via 116 by the above etching process and further erode other components of the light-emitting unit 103, a metal resistant to acid etching (such as including: copper, silver, gold, or platinum) can be used to form the conductive material 116a in the via 116. Additionally, in some embodiments, the above etching process also removes the protective layer on the same side as the first conductor layer (or the second conductor layer) and the third conductor layer (or the fourth conductor layer) that is not bonded to the substrate 118 (for example: Figure 1G the protective layer 112b of the light-emitting unit 103 on the right side in Figure 1G and the protective layer 112a of the light-emitting unit 103 on the left side in

[0127] are also removed).

[0128] Figure 2A , 2B , 3A, 3B, 4A, 4B, 5A, 5B illustrate some variations of the display device 10 of this embodiment. It should be noted that, unless otherwise specified, the same or similar components in these variations and the foregoing embodiments will be denoted by the same component symbols, and their forming methods can also be the same as or similar to the forming methods of the foregoing embodiments.

[0129] Figure 2A and Figure 2B illustrate the display device 20 of the present disclosure according to some embodiments. Specifically, Figure 2A is a partial top view of the display device 20, and Figure 2B is a cross-sectional view taken along the section line A-A of Figure 2A . It should be noted that, for the sake of simplicity, not all components of the display device 20 are illustrated in Figure 2A and Figure 2B .

[0130] One difference between the display device 20 and the display device 10 is that the shape of the light-emitting unit 103 of the display device 20 is designed to be circular or a symmetric polygon (for example: in the top view Figure 2A , the display device 20 is circular), which can overcome the light-emitting loss caused by left-right asymmetry.

[0131] Figure 3A and Figure 3BFIG. 30 illustrates a display device 30 of the present disclosure according to some embodiments. Specifically, Figure 3A is a partial top view of the display device 30, and Figure 3B is a cross-sectional view taken along the Figure 3A section line A-A. It should be noted that, for the sake of simplicity, not all components of the display device 30 are shown in Figure 3A and Figure 3B .

[0132] One difference between the display device 30 and the display device 20 of the foregoing embodiments is that the light-emitting unit 103 of the display device 30 includes a plurality of separate conductor layers. For example, as Figure 3A shown, in some embodiments, one side of the light-emitting unit 103 that is not joined to the substrate 118 includes four separate third conductor layers 110a, and one side joined to the substrate 118 also includes four separate fourth conductor layers 110b. Since the above-mentioned conductor layers are separate from each other, the lateral light emitted from the quantum well structure 104 of the light-emitting unit 103 can be reduced from being blocked, and the light-emitting efficiency can be improved. It should be understood that, although the example of one side of the light-emitting unit 103 including four separate third conductor layers 110a or fourth conductor layers 110b is used for illustration herein, the present disclosure is not limited thereto, and one side of the light-emitting unit 103 may include other numbers of third conductor layers 110a or fourth conductor layers 110b according to design requirements.

[0133] Figure 4A and Figure 4B FIGS. 40 illustrate a display device 40 of the present disclosure according to some embodiments. Specifically, Figure 4A is a partial top view of the display device 40, and Figure 4B is a cross-sectional view taken along the Figure 4A section line A-A. It should be noted that, for the sake of simplicity, not all components of the display device 40 are shown in Figure 4A and Figure 4B .

[0134] As Figure 4A and Figure 4B shown, one difference between the display device 40 and the display device of the foregoing embodiments is that the quantum well structure 104 of the light-emitting unit 103 of the display device 40 is disposed at the periphery of the light-emitting unit 103, so that the lateral light emitted from the quantum well structure 104 of the light-emitting unit 103 can be more effectively utilized to improve the light-emitting efficiency. As Figure 4B shown, in this embodiment, the through hole 116 and the conductive material 116a may also partially penetrate into the second semiconductor layer 106, but do not contact the first conductor layer 110a. In some other embodiments, such as Figure 1DAs shown, the through hole 116 and the conductive material 116a do not penetrate into the second semiconductor layer 106, but the present disclosure is not limited thereto.

[0135] Figure 5A and Figure 5B FIG. 50 shows a display device according to some embodiments of the present disclosure. Specifically, Figure 5A FIG. 50 is a partial top view of the display device 50, and Figure 5B FIG. 50 is a cross-sectional view taken along the section line A-A of Figure 5A . It should be noted that, for the sake of simplicity, not all components of the display device 50 are shown in Figure 5A and Figure 5B .

[0136] As Figure 5A and Figure 5B shown, one difference between the display device 50 and the display device 40 of the foregoing embodiment is that the light-emitting unit 103 of the display device 50 includes a plurality of separate quantum well structures 104, which can improve the light extraction efficiency. It should be understood that, although the light-emitting unit 103 including four separate quantum well structures 104 is taken as an example for illustration herein, the present disclosure is not limited thereto, and the light-emitting unit 103 may include other numbers of quantum well structures 104 according to design requirements.

[0137] It should be noted that, although not shown in the above figures, some other components (such as a cover plate or an optical film) may be formed on the display device of the foregoing embodiment. For example, the above cover plate may be formed of glass, indium tin oxide, polyimide, polyethylene terephthalate, other suitable materials, or a combination of the above, but the present disclosure is not limited thereto. For example, the above optical film may include a diffuser film, a condenser lens, other suitable optical films, or a combination of the above, but the present disclosure is not limited thereto.

[0138] In addition, for the sake of convenience of description, only one light-emitting unit of the display device is shown in some of the foregoing figures. However, those of ordinary skill in the art should understand that the display device may include any appropriate number of light-emitting units according to design requirements.

[0139] [Second Embodiment]

[0140] This embodiment provides a method for forming a display device by bonding a light-emitting unit (e.g., a light-emitting diode) to a substrate (e.g., a thin-film transistor). In the above method, an adhesive layer is first provided on a first substrate, and then a part of the adhesive layer is adhered to by the light-emitting unit, and the light-emitting unit is bonded to a second substrate such as a thin-film transistor substrate through this part to form the display device of this embodiment. Compared with the conventional bonding method of first bonding the entire adhesive layer to the second substrate and then bonding the light-emitting unit to the second substrate, the forming method of the display device of this embodiment has greater process flexibility and can be used to repair defective components.

[0141] Figures 6A to 6E Are a series of process cross-sectional views, which illustrate the method of forming the display device of this embodiment.

[0142] First, as Figure 6A Shown, an adhesive layer 602 is provided on the first substrate 600. In some embodiments, in subsequent processes, the adhesive layer 602 will be used to bond the light-emitting unit to another substrate.

[0143] In some embodiments, the adhesive layer 602 may be formed of a conductive material such as an anisotropic conductive adhesive. For example, the adhesive layer 602 may include a plurality of conductive particles 603 that are generally uniformly distributed therein. For example, any one of the conductive particles 603 may be substantially circular or elliptical in a cross-sectional view. For example, the diameter d1 of any one of the conductive particles 603 may be 0.1 to 10 micrometers.

[0144] In some embodiments, the conductive particles 603 may be spacers, which can be used to control the distance between the light-emitting unit and the substrate after bonding. In some embodiments, the length (or diameter) of the above spacer is less than the thickness of the conductor layer of the light-emitting unit (e.g., the conductor layers 608 and 610 described later). For example, the surface of the above spacer may be plated with a metal that can perform eutectic bonding or low-temperature soldering, such as including tin (Sn), silver (Ag), indium (In), copper (Cu), gold (Au), nickel (Ni), palladium (Pd), platinum (Pt), alloys of the above, or combinations of the above, but the present disclosure is not limited thereto.

[0145] In some embodiments, the adhesive layer 602 may also include an under fill film.

[0146] Please continue to refer to Figure 6A, the light-emitting unit 604 is moved onto the first substrate 600 and the light-emitting unit 604 is partially inserted into the adhesive layer 602. In some embodiments, a pick head 601 can be used to pick up the light-emitting unit 604 and move the light-emitting unit 604 above the adhesive layer 602, and then the pick head 601 is lowered so that the light-emitting unit 604 is imprinted on the adhesive layer 602.

[0147] In this embodiment, before the pick head 601 picks up the light-emitting unit 604, the mother board of the light-emitting unit 604 (not shown in the figure) has been removed, but the present disclosure is not limited thereto. In some other embodiments, when the pick head 601 picks up the light-emitting unit 604, the above-mentioned mother board of the light-emitting unit (e.g., sapphire substrate) has not been removed. Therefore, the above-mentioned mother board of the light-emitting unit can be located between the pick head 601 and the light-emitting unit 604, and the pick head 601 can control the movement of the light-emitting unit 604 by grasping and moving the above-mentioned mother board of the light-emitting unit. For example, after the light-emitting unit 604 is bonded to the second substrate described later, the above-mentioned mother board of the light-emitting unit can be removed by a process such as laser lift-off.

[0148] As Figure 6A shown, the light-emitting unit 604 can include a light-emitting body 606, a conductor layer 608, and a conductor layer 610. In some embodiments, the conductor layer 608 and the conductor layer 610 can be the same as or similar to the first conductor layer 108a and the third conductor layer 110a of the foregoing embodiments. In some other embodiments, the conductor layer 608 and the conductor layer 610 can be the same as or similar to the second conductor layer 108b and the fourth conductor layer 110b of the foregoing embodiments. For example, the first conductor layer (or the second conductor layer) 608 and the third conductor layer (or the fourth conductor layer) 610 can be electrodes of the light-emitting unit 604 and are electrically connected to the substrate of the display device.

[0149] Next, as Figure 6B shown, the light-emitting unit 604 can be lifted upward via the pick head 601, so that a part 602a of the adhesive layer 602 adheres to the light-emitting unit 604 and separates from the first substrate 600. Specifically, the part 602a of the adhesive layer 602 separated from the first substrate 600 can adhere to the first conductor layer (or the second conductor layer) 608 and the third conductor layer (or the fourth conductor layer) 610 of the light-emitting unit 604.

[0150] Next, as Figure 6CAs shown, in some embodiments, the gripping head 601 moves the light-emitting unit 604 and the portion 602a of the adhesive layer 602 onto the second substrate 612, and then the light-emitting unit 604 is bonded to the second substrate 612 via the portion 602a of the adhesive layer 602 and the gripping head 601 is moved away from the light-emitting unit 604. Specifically, in some embodiments, the first conductor layer (or the second conductor layer) 608 and the third conductor layer (or the fourth conductor layer) 610 of the light-emitting unit 604 can be bonded to the bonding pads (not individually shown in the figures) of the second substrate 612 via the portion 602a of the adhesive layer 602. For example, the above-mentioned bonding pads can be formed of a conductive material such as metal.

[0151] For example, the second substrate 612 can include one or more active components (not shown in the figures), such as transistors. For example, the second substrate 612 can be a thin-film transistor substrate. In some embodiments, the above-mentioned one or more active components can be electrically connected to the light-emitting unit 604 via the bonding pads of the second substrate 612 and the first conductor layer (or the second conductor layer) 608 and the third conductor layer (or the fourth conductor layer) 610. In some embodiments, the above-mentioned one or more active components can control or adjust the driving signal (such as a current signal) transmitted to the light-emitting unit 604 to adjust the brightness of the light-emitting unit 604.

[0152] In some embodiments, the step of bonding the light-emitting unit 604 to the second substrate 612 can include applying appropriate pressure (such as 1 to 100 MPa) and / or temperature (such as 100 to 300 °C) to the portion 602a of the adhesive layer 602 to increase the adhesion of the portion 602a of the adhesive layer 602, so that the portion 602a of the adhesive layer 602 can bond the light-emitting unit 604 and the second substrate 612.

[0153] In some embodiments, the step of bonding the light-emitting unit 604 to the second substrate 612 can include a eutectic bonding process. The eutectic bonding process may require specific metal materials (such as including tin alloys or silver-gold mixtures, etc.), and it may occur if the process temperature is raised to a suitable temperature. For example, the above-mentioned eutectic bonding process can cause a eutectic reaction between the first conductor layer (or the second conductor layer) 608, the third conductor layer (or the fourth conductor layer) 610 and the conductive particles 603, and between the bonding pads of the substrate 118 and the conductive particles 603 to bond the light-emitting unit 604 and the second substrate 612.

[0154] As described above, in some embodiments, the conductive particles 603 can be used as spacers to control the distance d2 between the light-emitting unit 604 and the substrate 612. In some embodiments where the conductive particles 603 can be spacers, the distance d2 between the light-emitting unit 604 and the second substrate 612 is approximately equal to the diameter d1 of any one of the conductive particles 603.

[0155] Next, as Figure 6D and Figure 6E shown, the above steps can be repeated to bond another light-emitting unit 604 to the substrate 618 via the portion 602b of the adhesive layer 602, thereby forming the display device 60 of the present disclosure. In some embodiments, the above steps can be repeated multiple times to bond light-emitting units 604 of multiple different colors (e.g., red, blue, and green) to the substrate 612 via the adhesive layer 602.

[0156] In some embodiments, each light-emitting unit 604 has its corresponding bonding step. In other words, in these embodiments, after a light-emitting unit 604 and the portion of the adhesive layer attached thereto are moved to the corresponding bonding pad of the second substrate 612, a corresponding bonding step is performed to bond the light-emitting unit to the second substrate 612. However, in some other embodiments, multiple light-emitting units 604 and the portions of the adhesive layer attached thereto can also be moved to the corresponding bonding pads of the second substrate 612 first, and then a single bonding step (e.g., applying the appropriate pressure and / or temperature described above or performing a eutectic bonding process) is performed to bond several light-emitting units 604 to the second substrate 612 simultaneously, thereby reducing the manufacturing steps and shortening the working hours.

[0157] In some embodiments, after several light-emitting units 604 are bonded to the second substrate 612, quality testing can be performed on the several light-emitting units 604. For example, if the quality of any one of the light-emitting units 604 is abnormal, the light-emitting unit 604 and the corresponding portion of the adhesive layer can be removed from the second substrate 612 (e.g., peeled off from the second substrate 612 by mechanical force), and then Figures 6A to 6C the steps described above can be performed to bond another light-emitting unit 604 to the second substrate 612 to replace the light-emitting unit 604 with abnormal quality. In other words, compared with the conventional bonding method of attaching the entire adhesive layer to the second substrate, the method of this embodiment can locally replace the light-emitting unit with abnormal quality, thereby increasing the manufacturing flexibility and achieving the effects of reducing manufacturing steps and shortening working hours.

[0158] Some variations of this embodiment are provided below. It should be noted that, unless otherwise specified, the same or similar components in these variations and the foregoing embodiments will be denoted by the same component symbols, and their forming methods can also be the same as or similar to the forming methods of the foregoing embodiments.

[0159] Figure 6F A display device 60' is shown, which illustrates some embodiments of the present disclosure. One difference between the display device 60' and the display device 60 is that the adhesive layer 602 of the display device 60' is formed of a non-conductive material. For example, the non-conductive material may include polyimide, a resin containing epoxy groups, silicon, photoresist, other suitable materials, or a combination of the above. In some embodiments, since the adhesive layer 602 is non-conductive, the first conductor layer (or the second conductor layer) 608 and the third conductor layer (or the fourth conductor layer) 610 of the light-emitting unit 604 are directly in contact with the bonding pads (not shown in the figure) of the second substrate 612 to electrically connect to the second substrate 612. In some embodiments, a eutectic reaction may be further performed between the first conductor layer (or the second conductor layer) 608 and the third conductor layer (or the fourth conductor layer) 610 and the bonding pads of the second substrate 612 to increase the bonding force between the two.

[0160] In some embodiments, the adhesive layer 602 may include a photocurable material and / or a thermosetting material. For example, the uncured adhesive layer 602 may be provided on the first substrate 600, and then the same or similar Figures 6A to 6E steps as described above are performed to transfer the light-emitting unit 604 and the corresponding portions 602a and / or 602b of the adhesive layer to the second substrate 612. Then, a photocuring and / or thermosetting process may be performed to cure the portions 602a and / or 602b of the adhesive layer 602 to increase its adhesion, so that the portions 602a and / or 602b of the adhesive layer 602 can bond the light-emitting unit 604 to the second substrate 612.

[0161] Figure 6G 、 6H are respectively a partial top view and a cross-sectional view of a display device 60'' that illustrates some embodiments of the present disclosure. Specifically, Figure 6H is a cross-sectional view taken along the Figure 6G section line B-B. In these embodiments, the gripping head 601 simultaneously grips a plurality of (for example: three, six, eight, hundreds, more than hundreds, or other appropriate numbers) light-emitting units 604 at a time, and bonds the gripped light-emitting units 604 to the second substrate 612 via a part of the adhesive layer 602 (for example: Figure 6G any one of the portions 602a - 602i shown). Then, the above steps may be repeated to have the gripping head 601 simultaneously grip a plurality of other light-emitting units 604 and bond the gripped light-emitting units 604 to the second substrate 612 via another part of the adhesive layer 602 (for example: Figure 6G another one of the portions 602a - 602i shown). In other words, in Figure 6GIn the illustrated embodiment, a gripper head 601 repeatedly picks up a plurality of light-emitting units 604 at once and bonds the picked-up light-emitting units 604 to a second substrate 612 via a part of the bonding layer 602 (for example, any one of parts 602a-602i). In some embodiments, as Figure 6G shown, any one of the plurality of separated parts 602a-602i of the bonding layer 602 may correspond to eight light-emitting units 604, but the present disclosure is not limited thereto. It should be understood that any one of the plurality of separated parts of the bonding layer 602 (for example, any one of parts 602a-602i) bonds the corresponding light-emitting unit 604 to the second substrate 612, and in a top view, any one of the plurality of separated parts of the bonding layer 602 overlaps or partially overlaps with the corresponding light-emitting unit 604. For example, as Figure 6G shown, any one of the plurality of separated parts 602a-602i of the bonding layer 602 overlaps with eight light-emitting units 604 and bonds the corresponding eight light-emitting units 604 to the second substrate 612.

[0162] As Figure 6G shown, in some embodiments, a plurality of parts of the bonding layer 602 of the display device 60” are aligned with each other in both the first direction Y and the second direction X (the second direction X may be substantially perpendicular to the first direction Y), but the present disclosure is not limited thereto. In some other embodiments, a plurality of parts of the bonding layer 602 may have a misalignment in at least one of the first direction Y and the second direction X. For example, in Figure 6I the illustrated embodiment, when viewed from the first direction Y, there is a misalignment between two adjacent columns of the bonding layer 602. Specifically, in Figure 6I the illustrated embodiment, there is a misalignment between the first column L1 (including parts 602a, 602b, and 602c) and the second column L2 (including parts 602d, 602e, 602f, and 602g) of the bonding layer 602, and there is also a misalignment between the second column L2 and the third column L3 (including parts 602h, 602i, and 602j). In some embodiments, the above misalignment may be defined as the distance between the centerlines of two adjacent parts of the bonding layer 602 (the two parts are respectively located on two adjacent columns) (for example, the distance M between the centerline F1 of part 602b of the first column L1 and the centerline F2 of part 602f of the second column L2).

[0163] Some other variations of this embodiment are provided below. It should be noted that unless otherwise specified, the same or similar components in these variations and the foregoing embodiments will be denoted by the same component symbols, and their forming methods may also be the same as or similar to the forming methods of the foregoing embodiments.

[0164] Figure 6Jis a partial top view of a display device 60a showing some embodiments of the present disclosure. It should be understood that, for the sake of simplicity, only several light-emitting units 604 of the display device 60a and several parts of the adhesive layer 602 corresponding to these light-emitting units 604 (e.g., parts 602a - 602d) are shown in Figure 6J As shown in Figure 6J , the adhesive layer 602 includes a plurality of generally adjacent parts (e.g., parts 602a - 602d). For the sake of convenience in the following description, part 602a, part 602b, part 602c, and part 602d may also be referred to as the first adhesive layer 602a, the second adhesive layer 602b, the third adhesive layer 602c, and the fourth adhesive layer 602d, respectively.

[0165] In some embodiments, the display device 60a may have a plurality of pixels V. For example, in some embodiments, one pixel V may correspond to (or include) at least one light-emitting unit 604 (as Figure 6J shown) and correspond to (or include) the part of the adhesive layer 602 corresponding to the light-emitting unit 604, but the present disclosure is not limited thereto. It should be understood that although only four pixels V are shown in Figure 6J , the present disclosure is not limited thereto, and the display device 60a may have any appropriate number of pixels V according to the design requirements.

[0166] As Figure 6J shown, one of the plurality of light-emitting units 604 may have a length P1 (e.g., 1 to 100 micrometers) in the first direction Y and a length P2 (e.g., 1 to 100 micrometers) in the second direction X (the second direction X may be generally perpendicular to the first direction Y). In some embodiments, the length P1 may be less than the length P2, but the present disclosure is not limited thereto. In some other embodiments, the length P1 may also be greater than or equal to the length P2. As Figure 6J shown, there may be a spacing Z1 in the first direction Y and a spacing Z2 in the second direction X between two adjacent light-emitting units 604. In some embodiments, the spacing Z1 may be 1 to 1000 micrometers, and the spacing Z2 may be 1 to 1000 micrometers.

[0167] As Figure 6J shown, one of the several adhesive layers of the display device 60a (e.g., one of the first adhesive layer 602a, the second adhesive layer 602b, the third adhesive layer 602c, and the fourth adhesive layer 602d) at least partially overlaps with the respective corresponding light-emitting unit 604. Specifically, as Figure 6JAs shown, in some embodiments, the first adhesive layer 602a, the second adhesive layer 602b, the third adhesive layer 602c, and the fourth adhesive layer 602d each partially overlap with a light-emitting unit 604. In some embodiments, as shown in FIG. 6J, there may be a spacing Z3 between adjacent adhesive layers in the first direction Y (e.g., the first adhesive layer 602a and the second adhesive layer 602b), and there may be a spacing Z4 between adjacent adhesive layers in the second direction X (e.g., the first adhesive layer 602a and the third adhesive layer 602c). In some embodiments, 0 < Z3 < (Z1 + P1) and / or 0 < Z4 < (Z2 + P2), which can reduce the problem of poor electrical connection between the light-emitting unit 604 and the second substrate 612 caused by insufficient adhesion due to too small an adhesion area between the adhesive layer and the light-emitting unit 604.

[0168] In some embodiments, as Figure 6K shown, one pixel V may correspond to three light-emitting units 604 and the adhesive layers corresponding to these three light-emitting units. For example, the three light-emitting units 604 corresponding to one of the several adhesive layers of the display device 60a (e.g., one of the first adhesive layer 602a, the second adhesive layer 602b, the third adhesive layer 602c, and the fourth adhesive layer 602d) may include a red light-emitting unit, a blue light-emitting unit, and a green light-emitting unit, but the present disclosure is not limited thereto. In some other embodiments, the three light-emitting units 604 corresponding to one of the several adhesive layers of the display device 60a may also all be light-emitting units of the same color.

[0169] Similarly, in some Figure 6K illustrated embodiments, 0 < Z3 < (Z1 + P1) and / or 0 < Z4 < (Z2 + P2), which can reduce the problem of poor electrical connection between the light-emitting unit 604 and the second substrate 612 caused by insufficient adhesion due to too small an adhesion area between the adhesive layer 602 and the light-emitting unit 604. It should be understood that although in the foregoing embodiments, one pixel V corresponds to three light-emitting units 604, and the three light-emitting units 604 corresponding to one of the several adhesive layers of the display device 60a (e.g., one of the first adhesive layer 602a, the second adhesive layer 602b, the third adhesive layer 602c, and the fourth adhesive layer 602d) are arranged in a column (or a row), the present disclosure is not limited thereto. In some other embodiments, the three light-emitting units 604 corresponding to one of the several adhesive layers of the display device 60a may also be arranged in a triangle (as Figure 6L , 6M shown).

[0170] Similarly, in some Figure 6LIn the embodiment illustrated in FIG. 6M, 0 < Z3 < (Z1 + P1) and / or 0 < Z4 < (Z2 + P2), which can reduce the problem of poor electrical connection between the light-emitting unit 604 and the second substrate 612 caused by insufficient adhesion due to too small an adhesion area between the adhesive layer 602 and the light-emitting unit 604.

[0171] In some other embodiments, one of the plurality of adhesive layers of the display device 60a (for example, one of the first adhesive layer 602a, the second adhesive layer 602b, the third adhesive layer 602c, and the fourth adhesive layer 602d) is disposed corresponding to six light-emitting units 604 (as Figure 6N shown). In these embodiments, the six light-emitting units 604 corresponding to one of the plurality of adhesive layers of the display device 60a may all be light-emitting units of the same color or include light-emitting units of different colors.

[0172] Similarly, in some Figure 6N In the embodiment illustrated in FIG. 6M, 0 < Z3 < (Z1 + P1) and / or 0 < Z4 < (Z2 + P2), which can reduce the problem of poor electrical connection between the light-emitting unit 604 and the second substrate 612 caused by insufficient adhesion due to too small an adhesion area between the adhesive layer 602 and the light-emitting unit 604.

[0173] It should be understood that in some other embodiments, one pixel V may correspond to any other appropriate number of light-emitting units 604 according to the design requirements.

[0174] The light-emitting unit 604 of this embodiment may also include the light-emitting unit 103 described in the foregoing first embodiment. In other words, the method described in this embodiment can be used to bond the light-emitting unit 103 to a substrate such as a thin-film transistor substrate.

[0175] [Third Embodiment].

[0176] This embodiment provides a method for bonding a light-emitting unit (for example, a light-emitting diode) to a substrate (for example, a thin-film transistor) to form a display device. In the above method, an adhesive layer is provided on a substrate such as a thin-film transistor substrate, and then the above adhesive layer is patterned by a photolithography process. Since the patterned adhesive layer is formed by a photolithography process, the formed pattern can have a smaller size and can be applied to bonding small-sized light-emitting units to the substrate of the display device (for example, a thin-film transistor substrate).

[0177] Figures 7A to 7D FIGS. 26-30 are a series of process cross-sectional views illustrating the method of forming the display device of this embodiment.

[0178] As Figure 7AAs shown, a substrate 700 is provided. In some embodiments, the substrate 700 may include one or more bonding pads disposed thereon. For example, in Figure 7A the illustrated embodiment, the substrate 700 includes four bonding pads C1, C2, C3, and C4, but the present disclosure is not limited thereto, and the substrate 700 may include any appropriate number of bonding pads according to design requirements (e.g., the number of light-emitting units bonded to the substrate 700). In some embodiments, the above bonding pads (e.g., C1, C2, C3, and C4) may be formed of a conductive material such as metal.

[0179] In some embodiments, two adjacent bonding pads C1, C2 and bonding pads C3, C4 may each correspond to different light-emitting units. As Figure 7A shown, there may be a spacing S1 between adjacent bonding pads corresponding to the same light-emitting unit (e.g., the spacing between bonding pads C1, C2 or the spacing between bonding pads C3, C4). In some embodiments, the spacing S1 is approximately equal to the spacing between the conductor layers (e.g., electrodes) of the light-emitting units to be bonded to the substrate 700. For example, the spacing S1 may be 2 to 200 micrometers.

[0180] In some embodiments, there may be a spacing S2 between adjacent bonding pads corresponding to different light-emitting units (e.g., the spacing between bonding pads C2 and C3). For example, when applied to a large display device, the spacing S2 can reach 50 millimeters (mm). However, as the display device miniaturizes, the spacing S2 also gradually decreases. In some embodiments, the spacing S2 can be as small as 2 micrometers (e.g., 2 micrometers to 500 micrometers). It should be understood that the present manufacturing method is applicable to both micro-devices and large display devices.

[0181] Next, as Figure 7B shown, an adhesive layer 704 is formed on the substrate 700, and the adhesive layer 704 may cover the bonding pads C1, C2 and the bonding pads C3, C4. In some embodiments, the adhesive layer 704 is formed of a non-conductive material. In some embodiments, the adhesive layer 704 is a photoresist material that can be patterned via a photolithography process. For example, the photoresist material may include, but is not limited to, polymethyl methacrylate (Acrylic), siloxane, or polyimide. In some embodiments, the adhesive layer 704 may include a photocurable material and / or a thermosetting material that has not been cured. For example, the adhesive layer 704 can be coated on the substrate 700 using a slit nozzle.

[0182] In some embodiments, after the step of coating the adhesive layer 704 on the substrate 700, a soft baking process may be performed to increase the adhesion of the adhesive layer 704 to the surface of the substrate 700.

[0183] Next, as Figure 7C shown, the adhesive layer 704 is patterned to form a patterned adhesive layer 704. For example, the above patterning step may include exposure, post-exposure baking, developing, other suitable processes, or a combination of the above.

[0184] In some embodiments, after the above patterning step, the patterned adhesive layer 704 may have a plurality of separate patterns (e.g., a first pattern 704A and a second pattern 704B) corresponding to different light-emitting units. In some embodiments, as Figure 7C shown, the first pattern 704A corresponds to the light-emitting units corresponding to the bonding pads C1 and C2, while the second pattern 704B corresponds to the light-emitting units corresponding to the bonding pads C3 and C4.

[0185] As mentioned above, with the miniaturization of the display device, the pitch S2 may gradually decrease, so the pitch S3 between the first pattern 704A and the second pattern 704B also gradually decreases (e.g., the pitch S3 can be reduced from 50 mm conventionally to 2 microns). Therefore, if the patterned adhesive layer 704 is formed by a conventional method such as screen printing, the pitch S3 will be too large and not conducive to the miniaturization of the display device. In contrast, the method described in this embodiment forms the patterned adhesive layer 704 by a photolithography process, so it has a smaller pitch S3 (e.g., the pitch S3 can be reduced to about 2 microns to 200 microns).

[0186] In addition, as the size of the light-emitting unit is reduced (e.g., the width), the widths W1 of the first pattern 704A and the second pattern 704B corresponding to the light-emitting unit also need to be reduced accordingly. Therefore, if the patterned adhesive layer 704 is formed by a conventional method such as screen printing, the width W1 will be too large and not suitable for bonding small-sized light-emitting units. In contrast, the method described in this embodiment forms the patterned adhesive layer 704 by a photolithography process, so the first pattern 704A and the second pattern 704B can have a smaller width W1. In some embodiments, the widths W1 of the first pattern 704A and the second pattern 704B can be reduced to about 8 microns (e.g., about 8 microns to 240 microns).

[0187] In some embodiments, as Figure 7CAs shown, after the above patterning step, the patterned adhesive layer 704 still covers the bonding pads C1, C2, C3, and C4 without exposing the top surfaces of the bonding pads C1, C2, C3, and C4 respectively. Further, in some embodiments, the pattern 704A covers the corresponding bonding pads C1, C2, while the pattern 704B covers the corresponding bonding pads C3, C4.

[0188] Next, as Figure 7D shown, the light-emitting unit 706 is inserted into the patterns 704A and 704B of the patterned adhesive layer 704.

[0189] In some embodiments, as Figure 7D shown, since the light-emitting unit 706 is inserted into the first pattern 704A and the second pattern 704B of the patterned adhesive layer 704 before the patterned adhesive layer 704 is cured, the materials of the first pattern 704A and the second pattern 704B can flow outward under the extrusion of the light-emitting unit 706. In some embodiments, as Figure 7D shown, after the step of inserting the light-emitting unit 706 into the first pattern 704A and the second pattern 704B of the patterned adhesive layer 704, the first pattern 704A and the second pattern 704B may have a curved sidewall profile.

[0190] Next, still as Figure 7D shown, a curing process (e.g., a thermal curing process and / or a light curing process) is performed to cure the patterned adhesive layer 704 to increase the adhesion of the patterned adhesive layer 704, so that the patterned adhesive layer 704 can bond the light-emitting unit 706 and the substrate 700 to form the display device 70 of the present disclosure. In some embodiments, since the cured patterned adhesive layer 704 can bond the light-emitting unit 706 and the substrate 700, no additional bonding process (e.g., an eutectic bonding process that causes the first conductor layer (or the second conductor layer) 710 and the third conductor layer (or the fourth conductor layer) 712 of the light-emitting unit 706 to undergo an eutectic reaction with the bonding pads C1, C2, C3, C4 of the substrate 700) is required to bond the first conductor layer (or the second conductor layer) 710 and the third conductor layer (or the fourth conductor layer) 712 of the light-emitting unit 706 to the bonding pads C1, C2, C3, C4 of the substrate 700, so as to electrically connect the substrate 700 and the light-emitting unit 706 via the bonding pads C1, C2, C3, C4 of the substrate 700.

[0191] As Figure 7DAs shown, adjacent light-emitting units 706 of the display device 70 may have a pitch S4. In some embodiments, since the patterned adhesive layer 704 is formed by a photolithography process, the first pattern 704A and the second pattern 704B may have a relatively small pitch S2, such that adjacent light-emitting units 706 may also have a relatively small pitch S4. As a result, the number of light-emitting units 706 per unit area can be increased, which is beneficial to the miniaturization of the display device. For example, in some embodiments, the pitch S4 can be reduced to about 2 micrometers (e.g., from about 2 micrometers to 200 micrometers).

[0192] Continuing from the foregoing, in some embodiments, since the patterned adhesive layer 704 is formed by a photolithography process, the first pattern 704A and the second pattern 704B may have a relatively small width W1 (e.g., from 8 micrometers to 240 micrometers). In other words, in these embodiments, the first pattern 704A and the second pattern 704B are suitable for bonding small-sized light-emitting units 706 to the substrate 700. For example, in some embodiments, the first pattern 704A and the second pattern 704B can be used to bond light-emitting units 706 having a width W2 of from 8 micrometers to 240 micrometers to the substrate 700.

[0193] In some embodiments, as Figure 7D shown, the first pattern 704A and the second pattern 704B may fill or partially fill the gap between the conductor layers 710 and 712 of the light-emitting unit 706, thereby increasing the strength of the light-emitting unit 706 fixed to the substrate 700. In some embodiments, since the first pattern 704A and the second pattern 704B surround the bonding pads C1, C2, C3, C4 of the conductor layers 710, 712 of the light-emitting unit 706 and the substrate 700, the bonding pads C1, C2, C3, C4 of the conductor layers 710, 712 of the light-emitting unit 706 and the substrate 700 can be protected from damage such as moisture.

[0194] Figures 8A to 8D Some variations of the method for forming the display device of this embodiment are illustrated. It should be noted that, unless otherwise specified, the same or similar components in these variations and the foregoing embodiments will be denoted by the same component symbols, and their forming methods may also be the same as or similar to the forming methods of the foregoing embodiments.

[0195] Figure 8A 、 Figure 8B 、 Figure 8C and Figure 8D The steps described are respectively the same as or similar to Figure 7A 、 Figure 7B 、 Figure 7C and Figure 7D The steps described, and therefore only the differences will be described below.

[0196] As Figure 8CAs shown, in some embodiments, the first pattern 704A and the second pattern 704B of the patterned adhesive layer 704 expose the top surfaces of bonding pads C1, C2 and bonding pads C3, C4. Specifically, in some embodiments, the first pattern 704A includes openings O1, O2 that expose bonding pads C1, C2, and the second pattern 704B includes openings O3, O4 that expose bonding pads C3, C4.

[0197] Next, as shown in FIG. 8D, the light-emitting unit 706 is bonded to the substrate 700 via the first pattern 704A and the second pattern 704B to form the display device 80 of the present disclosure. In some embodiments, as shown in FIG. 8D, since the first pattern 704A and the second pattern 704B include openings O1, O2 and O3, O4, and the conductor layers 710, 712 are inserted into the openings O1, O2, O3, and O4, the materials of the first pattern 704A and the second pattern 704B can generally be prevented from flowing outward due to the extrusion of the light-emitting unit 706, so that the first pattern 704A and the second pattern 704B can have generally straight sidewalls after the above bonding process.

[0198] In some embodiments, since the first pattern 704A and the second pattern 704B include openings O1, O2 and O3, O4, when the light-emitting unit 706 is bonded to the substrate 700, the situation where a large amount of the materials of the first pattern 704A and the second pattern 704B overflows outward can be improved.

[0199] In addition, the light-emitting unit 706 of this embodiment may also include the light-emitting unit 103 described in the foregoing first embodiment. In other words, the method described in this embodiment can be used to bond the light-emitting unit 103 to a substrate such as a thin-film transistor substrate.

[0200] [Fourth Embodiment].

[0201] This embodiment also provides a method for bonding a light-emitting unit (e.g., a light-emitting diode) to a substrate (e.g., a thin-film transistor) to form a display device. One difference between this embodiment and the third embodiment is that the adhesive layer used in this embodiment includes a conductive material. In other words, the light-emitting unit can be electrically connected to the substrate of the display device via the adhesive layer.

[0202] It should be noted that unless otherwise specified, the same or similar components in this embodiment and the foregoing embodiments will be denoted by the same component symbols, and their forming methods may also be the same as or similar to the forming methods of the foregoing embodiments.

[0203] Figure 9A , Figure 9B , Figure 9C and Figure 9D The steps described are respectively the same as or similar to Figure 7A ,Figure 7B , Figure 7C and Figure 7D the steps described above, so the following will only describe the different parts.

[0204] As Figure 9B shown, in some embodiments, the adhesive layer 704 may be formed of a photoresist material (e.g., acrylic, siloxane material, or polyimide (PI)), and a conductive material added to the photoresist material. In some embodiments, the adhesive layer 704 may include a photocurable material and / or a thermosetting material that has not been cured. For example, the conductive material may be an electrocarbon molecule (graphite, graphene, carbon nanotube), a metal particle (copper, tungsten, silver, tin, nickel, chromium, titanium, lead, gold, bismuth, antimony, zinc, zirconium, magnesium, indium, tellurium, gallium), or an alloy particle thereof, a conductive metal oxide particle (indium tin oxide (ITO), tin oxide (SnO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), antimony tin oxide (ATO), antimony zinc oxide (AZO)), or other suitable conductive materials, but the present disclosure is not limited thereto.

[0205] Next, as Figure 9C shown, the adhesive layer 704 is patterned. In some embodiments, the patterned adhesive layer 704 may include a first pattern 704A and a second pattern 704B, and the first pattern 704A may include two sub-patterns 704a while the second pattern 704B may include two sub-patterns 704b. In some embodiments, the two sub-patterns 704a of the first pattern 704A are separated from each other (the two sub-patterns 704b of the second pattern 704B are also separated from each other), and the occurrence of a short circuit between the first conductor layer (or the second conductor layer) 710 and the third conductor layer (or the fourth conductor layer) 712 of the light-emitting unit 706 bonded to the substrate 700 via the first pattern 704A and / or the second pattern 704B can be reduced.

[0206] Next, as Figure 9DAs shown, the light-emitting unit 706 is disposed on the patterned adhesive layer 704, and a process such as photo-curing and / or thermal-curing is performed to cure the patterned adhesive layer 704 to increase the adhesion of the patterned adhesive layer 704, so that the light-emitting unit 706 can be joined to the substrate 700 via the first pattern 704A and the second pattern 704B to form the display device 90 of the present disclosure. Specifically, in some embodiments, the two sub-patterns 704a of the first pattern 704A are respectively connected to the first conductor layer (or the second conductor layer) 710 and the third conductor layer (or the fourth conductor layer) 712 of a light-emitting unit 706, and the two sub-patterns 704b of the second pattern 704B are respectively connected to the first conductor layer (or the second conductor layer) 710 and the third conductor layer (or the fourth conductor layer) 712 of another light-emitting unit 706.

[0207] In some embodiments, since the patterned adhesive layer 704 has conductive properties, the first conductor layer (or the second conductor layer) 710 and the third conductor layer (or the fourth conductor layer) 712 can be electrically connected to the bonding pads C1, C2, C3, and C4 of the substrate 700 via the patterned adhesive layer 704. In other words, in these embodiments, the first conductor layer (or the second conductor layer) 710 and the third conductor layer (or the fourth conductor layer) 712 do not need to directly contact the bonding pads C1, C2, C3, and C4.

[0208] In addition, the light-emitting unit 706 of this embodiment may also include the light-emitting unit 103 described in the foregoing first embodiment. In other words, the method described in this embodiment can be used to join the light-emitting unit 103 to a substrate such as a thin-film transistor substrate.

[0209] It should be understood that the method of this embodiment can be applied to light-emitting units of various sizes (e.g., light-emitting diodes of various sizes). In some embodiments, the light-emitting unit is a light-emitting diode, and the chip size of the above-mentioned light-emitting diode is about 300 micrometers (μm) to 10 millimeters (mm), but the present disclosure is not limited thereto. In some embodiments, the light-emitting unit is a mini light-emitting diode (mini LED), and the chip size of the above-mentioned mini light-emitting diode is about 100 micrometers (μm) to 300 micrometers (μm), but the present disclosure is not limited thereto. In some embodiments, the light-emitting unit is a micro light-emitting diode (micro LED), and the chip size of the micro light-emitting diode is about 1 micrometer (μm) to 100 micrometers (μm), but the present disclosure is not limited thereto.

[0210] The foregoing has outlined features of several embodiments so that those of ordinary skill in the art may better understand various aspects of the present disclosure. Those of ordinary skill in the art should appreciate that they can readily design or modify other processes and structures based on the present disclosure and achieve the same purposes and / or achieve the same advantages as the embodiments introduced herein. Those of ordinary skill in the art should also understand that these equivalent structures do not depart from the spirit and scope of the present disclosure. Various changes, substitutions, or modifications can be made to the embodiments of the present disclosure without departing from the spirit and scope of the present disclosure.

Claims

1. A method of forming a display device, comprising: Providing a substrate, wherein a plurality of bonding pads are disposed on the substrate; Forming an adhesive layer on the substrate to cover the plurality of bonding pads; Forming a patterned adhesive layer corresponding to the plurality of bonding pads by a photolithography process; Bonding a light-emitting unit to at least one bonding pad via the patterned adhesive layer.

2. The method for forming a display device according to claim 1, wherein The step of bonding the light-emitting unit to at least one bonding pad includes performing a curing process to cure the patterned adhesive layer.

3. The method for forming a display device according to claim 1, wherein The light-emitting unit includes: A first conductor layer and a second conductor layer overlapping each other; A first semiconductor layer disposed between the first conductor layer and the second conductor layer; A second semiconductor layer disposed between the first semiconductor layer and the first conductor layer; A quantum well structure disposed between the first semiconductor layer and the second semiconductor layer; A via hole penetrating through the first semiconductor layer and the quantum well structure; and A conductive material disposed in the via hole, wherein the second conductor layer is electrically connected to the second semiconductor layer via the conductive material.

4. The method for forming a display device according to claim 1, wherein, Two adjacent bonding pads among the plurality of bonding pads have a spacing, and the spacing is from 2 micrometers to 500 micrometers.

5. The method for forming a display device according to claim 1, wherein The adhesive layer is a photoresist material, a photocurable material, or a thermosetting material.

6. The method for forming a display device according to claim 1, wherein, After the step of forming the adhesive layer on the substrate, a soft baking process is further included.

7. The method for forming a display device according to claim 1, wherein, The patterned adhesive layer has a curved sidewall profile.

8. The method for forming a display device according to claim 1, wherein The step of bonding the light-emitting unit to the at least one bonding pad includes: Inserting the light-emitting unit into the patterned adhesive layer when it has not been cured; and Performing a curing process to cure the patterned adhesive layer.

9. The method for forming a display device according to claim 1, wherein The step of bonding the light-emitting unit to the at least one bonding pad includes a eutectic bonding process in which the light-emitting unit and the bonding pad undergo a eutectic reaction.

10. The method for forming a display device according to claim 1, wherein, The patterned adhesive layer is used to increase the strength of the light-emitting unit on the substrate.

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