TWI661574B - Micro light emitting diode display micro light emitting diode and manufacturing methods thereof - Google Patents

Abstract

A manufacturing method of a miniature light emitting diode display. A first light emitting unit is formed, and a second light emitting unit is formed. Each of the first and second light emitting units has a first electrode and a second electrode. Forming first and second transparent extension electrodes having a first film thickness on each first light emitting unit and electrically connecting the first and second electrodes respectively to form a plurality of first light emitting elements and transferring the first light emitting elements To the element substrate and electrically connected to the element substrate. Forming first and second transparent extension electrodes having a second film thickness on each second light emitting unit and electrically connecting the first and second electrodes respectively to form a plurality of second light emitting elements and transferring the second light emitting elements To the component substrate. The first and second light-emitting elements are electrically connected to the element substrate through respective first and second connection electrodes.

Description

Mini light emitting diode display, micro light emitting diode element And its making method

The present invention relates to a display, and more particularly, to a miniature light emitting diode display, a miniature light emitting diode element, and a manufacturing method thereof.

Light-emitting diodes are self-luminous, and different types of light-emitting diodes can emit light at different wavelengths, as well as the advantages of low power consumption, high contrast, and high response speed. Therefore, micro light emitting diode displays (Micro light emitting Diode display (Micro LED display) is regarded as a possible replacement for liquid crystal display (LCD) as the mainstream of next-generation display technology. In recent years, LED display technology has become more and more mature and can be applied to smart phones, TVs, computer monitors and other products. Therefore, the industry is more committed to the development of miniature LED displays to make LED displays With higher resolution.

In order to connect the LED to the element substrate, some micro LED displays are covered with a transparent conductive material on the LED as a bridge electrically connected to the element substrate to avoid affecting the light emitting efficiency of the LED. Because the resistance of transparent conductive materials is higher than gold It is high, so the RC loading is high. Therefore, how to reduce the resistance-capacitance load of the transparent conductive material without affecting the light emitting efficiency of the LED is an issue that the industry is desperately trying to solve.

The invention relates to a micro-light-emitting diode display, a micro-light-emitting diode element and a manufacturing method thereof. Will increase the difficulty of the process and improve the efficiency of the process.

According to one aspect of the present invention, a method for manufacturing a miniature light emitting diode display is provided, which includes the following steps. Forming a plurality of first light-emitting units, each first light-emitting unit includes a first electrode and a second electrode, wherein each first light-emitting unit has a first side wall, a second side wall, and an insulating layer, and the first electrode is adjacent to the first The sidewall and the second electrode are adjacent to the second sidewall, and the insulating layer covers the first sidewall and the second sidewall. Forming a plurality of second light-emitting units, each second light-emitting unit includes a first electrode and a second electrode, wherein each second light-emitting unit has a first side wall, a second side wall and an insulating layer, and the first electrode is adjacent to the first The sidewall and the second electrode are adjacent to the second sidewall, and the insulating layer covers the first sidewall and the second sidewall. A first transparent extension electrode and a second transparent extension electrode are respectively formed on the insulating layers of the first side wall and the second side wall of each first light-emitting unit, and the first electrodes of the corresponding first light-emitting units are electrically connected with The second electrode forms a plurality of first light emitting elements for emitting a first color light, wherein the first transparent extension electrode and the second transparent extension electrode of each first light emitting element have a first film thickness T1. Forming a first transparent extension electrode and a first transparent extension electrode, respectively Two transparent extension electrodes are on the insulating layer of the first side wall and the second side wall of each second light-emitting unit, and the first electrode and the second electrode of the corresponding second light-emitting unit are electrically connected respectively to form a plurality of second light-emitting units. An element for emitting a second color light different from the first color light, wherein the first transparent extension electrode and the second transparent extension electrode of each second light emitting element have a second film thickness T2, and the second film thickness T2 is different To the first film thickness T1. The first light emitting elements and the second light emitting elements are disposed on an element substrate, and the element substrate has a plurality of first pads and a plurality of second pads. A plurality of first connection electrodes and a plurality of second connection electrodes are formed on the element substrate. Each first connection electrode is electrically connected to a corresponding first transparent extension electrode and a corresponding first pad, and each second connection electrode is electrically connected to correspond to each other. Each of the second transparent extension electrodes and the corresponding second pad.

According to one aspect of the present invention, a miniature light-emitting diode is provided, including: a light-emitting unit. The light-emitting unit includes a first electrode, a light-emitting structure, and a second electrode. Each first light-emitting unit has a first side wall, a A second sidewall and an insulating layer, the first electrode is adjacent to the first sidewall and the second electrode is adjacent to the second sidewall; the insulating layer covers the first sidewall and the second sidewall; The light emitting unit is formed on the insulating layer of the first side wall and the second side wall of the light emitting unit, and the first electrode and the second electrode are respectively electrically connected to form a light emitting element for emitting a color light. A transparent extension electrode and a second transparent extension electrode have a first film thickness, wherein if the color light emitted by the light emitting element has a main wavelength range of 480nm to 750nm, the first film thickness is between 2000 Angstroms and 2300 Angstroms; and The colored light emitted by the light-emitting element has a main wavelength range of 380 nm to 480 nm, and the first film thickness is between 200 angstroms and 500 angstroms.

According to an aspect of the present invention, a miniature light emitting diode display is provided, which includes an element substrate, a plurality of first light emitting elements, a plurality of second light emitting elements, a plurality of first connection electrodes, and a plurality of second connection electrodes. The first light emitting element is disposed on the element substrate, and the first light emitting element is used to emit a first color light. The second light-emitting element is disposed on the element substrate. The second light-emitting element is used to emit a second color light, and the color of the first color light and the second color light are different. Each of the first and second light-emitting elements includes a first electrode, a second electrode, a first transparent extension electrode, and a second transparent extension electrode. The first transparent extension electrode is electrically connected to the first electrode, the second transparent extension electrode is electrically connected to the second electrode, and the first transparent extension electrode and the second transparent extension electrode of each first light-emitting element have a first film thickness, and The first transparent extension electrode and the second transparent extension electrode of each second light-emitting element have a second film thickness, and the first film thickness is different from the second film thickness. The first connection electrode and the second connection electrode are respectively disposed on each of the first and second light-emitting elements, wherein each of the first connection electrodes is electrically connected to a corresponding first transparent extension electrode and a corresponding first pad, and each of the second The connection electrodes are electrically connected to the corresponding second transparent extension electrodes and the corresponding second pads.

According to an aspect of the present invention, a method for manufacturing a micro-light emitting diode display is provided, which includes the following steps. A first semiconductor layer, an active layer, and a second semiconductor layer are formed on a first substrate. The active layer is located between the first semiconductor layer and the second semiconductor layer. The first semiconductor layer, the active layer, and the second semiconductor layer are patterned to form a plurality of light emitting structures. A portion of the second semiconductor layer and a portion of the active layer above the first semiconductor layer in each light emitting structure are removed to form a plurality of light emitting units having a first semiconductor layer with an exposed portion. Forming an insulating layer to emit light On the unit, each light-emitting unit includes a first side wall and a second side wall, the first side wall is located on one side of each light-emitting unit, the second side wall is located on the other side of each light-emitting unit, and the insulating layer covers the first side of each light-emitting unit. A side wall and a second side wall. A first electrode is formed on each of the second semiconductor layers of each light-emitting unit. A second electrode is formed on each exposed portion of the first semiconductor layer of each light-emitting unit. A first transparent extension electrode and a second transparent extension electrode are formed on the insulating layer of each light-emitting unit, each first transparent extension electrode is electrically connected to the first electrode of the corresponding light-emitting unit, and each second transparent extension electrode is electrically The second electrode of the corresponding light-emitting unit is connected to form a plurality of light-emitting elements. The first transparent extension electrode and the second transparent extension electrode have a first film thickness. These light-emitting elements are transferred to a second substrate, and the second substrate has a first pad and a second pad corresponding to each light-emitting element. A first connection electrode and a second connection electrode are respectively formed on each light-emitting element, and each first connection electrode electrically connects a first transparent extension electrode of a corresponding light-emitting element and a corresponding first pad, and each second connection electrode The second transparent extension electrode of the corresponding light-emitting element is electrically connected to the corresponding second pad.

In order to have a better understanding of the above and other aspects of the present invention, the following specific examples are described in detail below in conjunction with the accompanying drawings:

100, 100’‧‧‧ mini light emitting diode display

101‧‧‧ the first substrate

102‧‧‧first light emitting structure

1021‧‧‧First semiconductor layer

1022‧‧‧Active Level

1023‧‧‧Second semiconductor layer

1025‧‧‧ Insulation

1031‧‧‧First sidewall

1032‧‧‧Second sidewall

1033‧‧‧First electrode

1034‧‧‧Second electrode

103a‧‧‧first light emitting unit

103b‧‧‧Second light emitting unit

103c‧‧‧third light emitting unit

104a, 104b, 104c‧‧‧First transparent extension electrode

105a, 105b, 105c‧‧‧Second transparent extension electrode

106a‧‧‧first light emitting element

106b‧‧‧Second light emitting element

106c‧‧‧third light emitting element

107a, 107b, 107c‧‧‧First connection electrode

108a, 108b, 108c‧‧‧Second connection electrode

109a‧‧‧Adhesive layer

110‧‧‧Element substrate

1101‧‧‧The first pad

1102‧‧‧Second pad

T1‧‧‧First film thickness

T2‧‧‧Second film thickness

T3‧‧‧ Third film thickness

d1‧‧‧first electrode film thickness

d2‧‧‧Second electrode film thickness

d3‧‧‧third electrode film thickness

A1‧‧‧Width

B1‧‧‧Width

FIG. 1 is a schematic diagram of a micro-light emitting diode display according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a micro-light emitting diode display according to an embodiment of the present invention.

3A-3H are schematic diagrams illustrating a method for manufacturing a micro-luminescent diode display according to an embodiment of the present invention.

FIG. 4 is a schematic top view of the first light emitting element in FIG. 3H.

FIG. 1 is a schematic diagram of a micro-light emitting diode display 100 according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a micro-light emitting diode display 100 'according to another embodiment of the present invention.

According to the definition of current technology development, micro-light-emitting diodes generally have light-emitting diodes with an edge length ranging from micrometers to hundreds of micrometers. Micro-light-emitting diode displays 100, 100 'include a plurality of light-emitting elements arranged in an array. For convenience, FIG. 1 shows only one first light emitting element 106a and one second light emitting element 106b, two first connection electrodes 107a, 107b, two second connection electrodes 108a, 108b, and two of the plurality of light emitting elements. First pads 1101 and two second pads 1102. In addition, FIG. 2 shows only one first light emitting element 106a, one second light emitting element 106b, one third light emitting element 106c, three first connection electrodes 107a, 107b, 107c, and three third light emitting elements. Two connection electrodes 108a, 108b, 108c, three first pads 1101, and three second pads 1102.

Please refer to FIG. 1. According to an embodiment of the present invention, a micro-light emitting diode display 100 includes an element substrate 110, a first light-emitting element 106a, a second light-emitting element 106b, first connection electrodes 107a, 107b, and a second connection electrode 108a. , 108b. The element substrate 110 includes a first pad 1101 and a second pad 1102 corresponding to the first and second light emitting devices 106a and 106b, respectively. The first light emitting element 106a is disposed on the element substrate 110, and the first light emitting element 106a is configured to emit light of a first color. The second light emitting element 106b is disposed on the element substrate 110, and the second light emitting element 106b is configured to emit light of a second color different from the first color. In this embodiment, the first light emitting element 106a is, for example, a red or green light emitting diode, and the color light emitted by the first light emitting element 106a has a main wavelength range between 480nm and 750nm. The second light emitting element 106b is, for example, blue light The colored light emitted by the light-emitting diode has a main wavelength range between 380 nm and 480 nm.

In FIG. 1, the first connection electrode 107 a on the first light emitting element 106 a may be electrically connected to the first transparent extension electrode 104 a on the first light emitting element 106 a and the first pad 1101 corresponding to the first light emitting element 106 a. The second connection electrode 108a may be electrically connected to the second transparent extension electrode 105a on the first light emitting element 106a and the second pad 1102 corresponding to the first light emitting element 106a.

In an embodiment, the first transparent extension electrode 104a and the second transparent extension electrode 105a on the first light emitting element 106a have a first film thickness T1, and the first film thickness T1 is, for example, between 2000 angstroms and 2300 angstroms. In addition, the first connection electrode 107a and the second connection electrode 108a on the first light emitting element 106a have a first electrode film thickness d1, and the first electrode film thickness d1 is, for example, between 500 angstroms and 800 angstroms.

In the first figure, the first connection electrode 107b on the second light-emitting element 106b can be electrically connected to the first transparent extension electrode 104b on the second light-emitting element 106b and the first pad 1101 corresponding to the second light-emitting element 106b. And the second connection The electrode 108b can be electrically connected to the second transparent extension electrode 105b on the second light emitting element 106b and the second pad 1102 corresponding to the second light emitting element 106b.

In this embodiment, the first transparent extension electrode 104b and the second transparent extension electrode 105b on the second light emitting element 106b have a second film thickness T2, and the second film thickness T2 is, for example, between 500 angstroms and 800 angstroms. In addition, the first connection electrode 107b and the second connection electrode 108b on the second light emitting element 106b have a second electrode film thickness d2, and the second electrode film thickness d2 is, for example, between 500 angstroms and 800 angstroms.

In this embodiment, the first transparent extension electrode 104a and the second transparent extension electrode 105a on the first light emitting element 106a may be different from the first transparent extension electrode 104b and the second transparent extension electrode 105b on the second light emitting element 106b. After forming different first film thicknesses T1 and second film thicknesses T2 on the epitaxial substrate or different transition substrates, the first light emitting element 106a and the second light emitting element 106b are transferred onto the same element substrate 110, and First connection electrodes 107a, 107b and second connection electrodes 108a, 108b having the same electrode film thickness are formed on the first light emitting element 106a and the second light emitting element 106b, respectively.

For example, a first transparent extension electrode 104a and a second transparent extension electrode 105a having a first film thickness T1 are first formed on the first light emitting element 106a, and then a first connection electrode 107a having a first electrode film thickness d1 and The second connection electrode 108a is on the first light-emitting element 106a. The total thickness of the first film thickness T1 and the first electrode film thickness d1 is approximately 2800 angstroms. Since the film thickness is 2800 angstroms of a transparent conductive material (such as indium tin oxide) (Or indium zinc oxide) is suitable for light with a wavelength in the red or green wavelength band, so this embodiment controls the total thickness of the first film thickness T1 and the first electrode film thickness d1. It is controlled at about 2800 angstroms, thereby improving the transmittance of the red or green light emitting diode element to the transparent conductive material.

In addition, a first transparent extension electrode 104b and a second transparent extension electrode 105b having a second film thickness T2 are first formed on the second light emitting element 106b, and then a first connection electrode 107b and a second connection electrode having a second electrode thickness d2 are formed. The connection electrode 108b is connected to the second light-emitting element 106b. The total thickness of the second film thickness T2 and the second electrode film thickness d2 is approximately between 1000 angstroms and 2000 angstroms. A transparent conductive material (such as indium tin oxide or indium zinc oxide) is suitable for light transmission at a wavelength in the blue light band. Therefore, in this embodiment, the total thickness of the second film thickness T2 and the second electrode film thickness d2 is controlled to 1000 angstroms and Between 2000 angstroms, and further improve the transmittance of blue light-emitting diode elements to transparent conductive materials.

According to the above description, it is known that 1.4 <(T1 + d1) / (T2 + d2) <2.8, where T1 is greater than T2, and d1 = d2, the overall transmittance is improved and the display brightness effect is better.

In addition, please refer to FIG. 2. The micro-light-emitting diode display 100 'in FIG. 2 is substantially the same as the micro-light-emitting diode display 100 in FIG. 1. The difference is that the micro-light-emitting diode in FIG. The body display 100 'further includes a third light-emitting element 106c, and the first connection electrode 107c on the third light-emitting element 106c can be connected to the first transparent extension electrode 104c on the third light-emitting element 106c and the first light-emitting element corresponding to the third light-emitting element 106c. A pad 1101 is electrically connected, and the second connection electrode 108c can be electrically connected to the second transparent extension electrode 105c on the third light emitting element 106c and the second pad 1102 corresponding to the third light emitting element 106c.

The third light emitting element 106c is disposed on the element substrate 110, and the third light emitting element 106c is configured to emit light of a third color different from the first color and the second color. The third light emitting element 106c is, for example, red light or green. The light-emitting diode emits colored light with a dominant wavelength range between 480 nm and 750 nm. When the first light emitting element 106a is a red light emitting diode and the third light emitting element 106c is a green light emitting diode, conversely, when the first light emitting element 106a is a green light emitting diode and the third light emitting element 106c is red Light-emitting diode.

In an embodiment, the first transparent extension electrode 104c and the second transparent extension electrode 105c on the third light emitting element 106c have a third film thickness T3, and the third film thickness T3 may be equal to the first film thickness T1, for example, between 2000 Angstroms to 2300 Angstroms. In addition, the first connection electrode 107c and the second connection electrode 108c on the third light emitting element 106c have a third electrode film thickness d3, and the third electrode film thickness d3 may be equal to the first electrode film thickness d1, for example, between 500 angstroms and 800 angstroms. Between Egypt. The total thickness of the third film thickness T3 and the third electrode film thickness d3 is approximately 2800 angstroms. Since the transparent conductive material (such as indium tin oxide or indium zinc oxide) with a film thickness of 2800 angstroms is suitable for red or green light bands Light at a wavelength of 50 Å, so in this embodiment, the total thickness of the third film thickness T3 and the third electrode film thickness d3 is controlled to about 2800 angstroms, thereby improving the red or green light emitting diode element for transparent conductive materials. Penetration.

In one embodiment, the first transparent extension electrode 104a and the second transparent extension electrode 105a on the first light emitting element 106a, the first transparent extension electrode 104b and the second transparent extension electrode 105b on the second light emitting element 106b, and the third The first transparent extended electrode 104c and the second transparent extended electrode 105c on the light emitting element 106c After forming the first electrode thickness T1, the second film thickness T2, and the third film thickness T3 respectively on different epitaxial substrates or different transition substrates, the first light emitting element 106a and the second light emitting element 106b can be formed. And the third light emitting element 106c is placed on the same element substrate 110, and first connection electrodes 107a, 107b, and 107c and second connection electrodes 108a, 108b, and 108c having the same electrode film thickness are formed on the first light emitting element 106a and the second On the light-emitting element 106b and the third light-emitting element 106c, a transparent conductive material having different film thicknesses on different light-emitting diodes is achieved.

The miniature light emitting diode display 100 'of this embodiment can be combined into white light emitting units through light emitting diodes of three colors of red, green, and blue, or white light emitting units can be combined with light emitting diodes of other colors. The light-emitting diodes can be controlled by separate thin-film transistors (TFTs), so that the light of different colors is mixed in the respective display units, and then the light is emitted through the display surface of the micro-light-emitting diode display 100 'to improve the color. saturation.

The manufacturing method of the micro light-emitting diode display is described in detail below. The embodiments are only used as examples, and are not intended to limit the scope of the present invention. Since the manufacturing methods of the first light-emitting element 106a, the second light-emitting element 106b, and the third light-emitting element 106c are substantially the same, the following embodiments only describe the manufacturing method of the first light-emitting element 106a.

Referring to FIGS. 3A to 3H, a method of manufacturing a micro-light emitting diode display 100 according to an embodiment of the present invention is as follows. In FIG. 3A, a first light emitting structure 102 is formed on a first substrate 101. The first light emitting structure 102 includes a first semiconductor layer 1021, an active layer 1022, and a second semiconductor layer 1023. The active layer 1022 Located between the first semiconductor layer 1021 and the second semiconductor layer 1023. The first substrate 101 is, for example, a sapphire substrate or a silicon carbide substrate. By performing an epitaxial process on the first substrate 101, the first semiconductor layer 1021, the active layer 1022, and the second semiconductor layer 1023 can be transferred from the surface of the first substrate 101. Formed in order and stacked on top of each other. The first semiconductor layer 1021 is, for example, an N-type semiconductor layer, and the second semiconductor layer 1023 is, for example, a P-type semiconductor layer. The first semiconductor layer 1021 and the second semiconductor layer 1023 have different electrical properties. In addition, the active layer 1022 may be a multiple quantum well layer, which is located between the first semiconductor layer 1021 and the second semiconductor layer 1023 having different electrical properties, so that conductive electrons and holes pass through the first semiconductor layer 1021 and the second semiconductor layer, respectively. The semiconductor layer 1023 is transmitted to the active layer 1022 and combined with each other, and then emits energy in the form of light.

The material of the first semiconductor layer 1021, the active layer 1022, and the second semiconductor layer 1023 may be composed of a nitride of a group IIIA element of the periodic table. One or a combination of a group consisting of aluminum gallium nitride (AlGaN) and aluminum indium gallium nitride (AlInGaN), but not limited thereto.

In FIG. 3B, the first light emitting structure 102 is patterned to form a plurality of first light emitting units 103 a on the first substrate 101. Next, in FIG. 3C, a portion of the second semiconductor layer 1023 and a portion of the active layer 1022 located above the first semiconductor layer 1021 in each of the first light-emitting units 103a are etched to form a first layer having an exposed portion 1024. Semiconductor layer 1021. Each first light emitting unit 103a has a first sidewall 1031 and a second sidewall 1032. The first sidewall 1031 is located in each One side of a light emitting unit 103a, and the second side wall 1032 is located on the other side of each first light emitting unit 103a.

Next, in FIG. 3D, an insulating layer 1025 is formed on each first light emitting unit 103a, and the insulating layer 1025 covers the first sidewall 1031 of each first light emitting unit 103a and the second sidewall 1032 of each first light emitting unit 103a. The insulating layer 1025 is, for example, a material with poor conductivity such as silicon oxide, silicon nitride, or silicon oxynitride, but is not limited to the examples mentioned above.

In FIG. 3E, a first electrode 1033 is formed on the second semiconductor layer 1023 of each first light emitting unit 103a, and a second electrode 1034 is formed on the exposed portion 1024 of the first semiconductor layer 1021 of each first light emitting unit 103a. . The first electrode 1033 may be directly formed on the second semiconductor layer 1023 or formed on the second semiconductor layer 1023 through an ohmic contact layer to reduce the contact resistance between the first electrode 1033 and the second semiconductor layer 1023.

In FIG. 3F, a first transparent extension electrode 104a and a second transparent extension electrode 105a are formed on each first light emitting unit 103a to form a plurality of first light emitting elements 106a. The first transparent extension electrode 104a is at least partially covered on the insulation layer 1025 of the first sidewall 1031, the second transparent extension electrode 105a is at least partially covered on the insulation layer 1025 of the second sidewall 1032, and the first transparent extension electrode 104a is electrically connected to the first The first electrode 1033 and the second transparent extension electrode 105a of a light-emitting element 106a are electrically connected to the second electrode 1034 of the first light-emitting element 106a. The first transparent extension electrode 104a and the second transparent extension electrode 105a have a first film thickness T1.

The first transparent extended electrode 104b and the second transparent extended electrode 105b on the second light emitting element 106b in FIG. 2 and the first transparent extended electrode 104c and the second transparent extended electrode 105c on the third light emitting element 106c are similar to the first The first transparent extension electrode 104a and the second transparent extension electrode 105a on a light-emitting element 106a differ only in film thickness or material, and are not repeated here.

The material of the first transparent extension electrode 104a and the second transparent extension electrode 105a is, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or other transparent conductive materials. In addition, the material of the first transparent extension electrode 104a and the second transparent extension electrode 105a may also be a conductive polymer, a nano carbon tube, or a nano metal. In another embodiment, for example, the first light emitting unit 103a is formed on a transition substrate, and then the first transparent extension electrode 104a and the second transparent extension electrode 105a are formed on the first light emitting unit 103a to form a plurality of The light emitting element 106a is on a transition substrate.

In FIG. 3G, the first light-emitting element 106a is transferred to the element substrate 110 or first to a transition substrate (not shown) and then transferred to the element substrate 110. The element substrate 110 has a The first pad 1101 and the second pad 1102. In this embodiment, after forming the first transparent extension electrode 104 a and the second transparent extension electrode 105 a on each of the first light emitting units 103 a, the first light emitting element 106 a can be directly transferred to the element substrate 110. Alternatively, before forming the first transparent extension electrode 104a and the second transparent extension electrode 105a before each of the first light emitting units 103a, the first light emitting unit 103a may be transferred to a first transition substrate (not shown), and wait until the first light emitting unit 103a is formed. A transparent extension electrode 104a and a second transparent extension electrode The extension electrode 105 a is after each of the first light emitting units 103 a, and then the first light emitting element 106 a is transferred onto the element substrate 110.

Similarly, the second light emitting element 106b and the third light emitting element 106c in FIG. 2 can also be transferred to the second and third transition substrates (not shown), respectively, and wait until the first transparent extension electrodes 104b, 104c, and the first After the two transparent extension electrodes 105b and 105c are after the second light emitting unit 103b and the third light emitting unit 103c, the second light emitting element 106b and the third light emitting element 106c are transferred to the element substrate 110, respectively.

In FIG. 3H, a first connection electrode 107a and a second connection electrode 108a are formed on the element substrate 110. The first connection electrode 107a is electrically connected to the first transparent extension electrode 104a and the first pad 1101, and the second connection electrode 108a. The second transparent extension electrode 105a is electrically connected to the second pad 1102.

In FIG. 2, the first connection electrode 107 b and the second connection electrode 108 b on the second light emitting element 106 b and the first connection electrode 107 c and the second connection electrode 108 c on the third light emitting element 106 c may be on the first light emitting element 103 a. The first connection electrode 107a and the second connection electrode 108a are formed at the same time, and therefore have the same electrode film thickness.

The material of the first connection electrode 107a and the second connection electrode 108a is, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or other transparent conductive materials. In addition, the material of the first connection electrode 107a and the second connection electrode 108a may also be a conductive polymer, a nano carbon tube, or a nano metal.

In one embodiment, the material of the first transparent extension electrode 104a and the second transparent extension electrode 105a and the material of the first connection electrode 107a and the second connection electrode 108a may be different transparent conductive materials, such as indium tin oxide (ITO). ) Or indium zinc oxide (IZO). The first light-emitting element 106a of this embodiment can pass through the combination of two transparent conductive materials to make light transmittance better.

In another embodiment, a material of the first connection electrode 107a and the second connection electrode 108a may be a metal, such as a titanium alloy, an aluminum alloy, or a titanium-aluminum-titanium (Ti-Al-Ti) alloy. Since the resistance value of the metal material is low, the influence of the excessive resistance on the display panel can be reduced, for example, the problem of RC loading can be reduced.

Referring to FIG. 3H, when the material of the first connection electrode 107a and the second connection electrode 108a is metal, the first connection electrode 107a and the first electrode 1033 do not overlap in a direction perpendicular to the element substrate 110 to avoid the first The colored light emitted by a light emitting element 106a is reflected by the first connection electrode 107 of a metallic material, so that the light emitting effect of the first light emitting element 106a is better.

In addition, in consideration of improving the light emitting effect, the first connection electrode 107a and the first transparent extension electrode 104a are overlapped on the first side wall 1031 of the first light emitting element 106a, so that the colored light emitted by the first light emitting element 106a passes through the first side wall. At 1031, it has a high transmittance, which further improves the light emitting effect of the first light emitting element 106a.

In addition, in consideration of improving the light emitting effect, the first connection electrode 107 a and the first transparent extension electrode 104 a are parallel to the first connection electrode 107 in a direction parallel to the element substrate 110. The active layer 1022 of a light-emitting element 106a overlaps, so that the electrical distribution of the active layer 1022 of the first light-emitting element 106a is better, the luminous efficiency is better, and the level of colored light emitted has a higher transmittance when passing through the overlapping area, thereby improving Light emitting effect of the first light emitting element 106a.

The above-mentioned manufacturing method of the first light-emitting element 106a can also be applied to the manufacturing method of the second light-emitting element 106b and the third light-emitting element 106c. The only difference is the first transparent extension electrode 104b and the second transparent extension on the second light-emitting element 106b. The first transparent extension electrode 104c and the second transparent extension electrode 105c on the electrode 105b and the third light emitting element 106c have a second film thickness T2 and a third film thickness T3, respectively, and then the first light emitting element 106a and the second light emitting element 106b and the third light-emitting element 106c are placed on the same element substrate 110, and first connection electrodes 107a, 107b, 107c and second connection electrodes 108a, 108b, 108c having the same electrode film thickness are formed on the first light-emitting element 106a, On the second light emitting element 106b and the third light emitting element 106c.

Please refer to FIGS. 3H and 4, where FIG. 4 is a schematic top view of the first light emitting element 106 a in FIG. 3H. In FIG. 3H, an adhesive layer 109a is provided at the bottom of the first light emitting element 106a to fix the first light emitting element 106a on the element substrate 110, and the first connection electrode 107a is electrically connected to the first pad 1101, and the first connection There is no adhesion layer 109a between the contact positions of the electrode 107a and the first pad 1101. In addition, the second connection electrode 108a is also electrically connected to the second pad 1102. In an embodiment, the first connection electrode 107a and the second connection electrode 108a may extend along a predetermined direction, and the first connection electrode 107a and the second connection electrode are connected in a predetermined extension direction. The width B1 of the electrode 108a is at least two times greater than the width A1 of the first transparent extension electrode 104a and the second transparent extension electrode 105a, that is, B1> 2A1, to reduce the impedance of the first connection electrode 107a and the second connection electrode 108a without affecting Light emission efficiency of the first light emitting element 106a. In terms of area ratio, the area of the first connection electrode 107a and the second connection electrode 108a perpendicular to the element substrate 110 is larger than the area of the first transparent extension electrode 104a and the second transparent extension electrode 105a perpendicular to the element substrate 110. More than twice.

The micro-light emitting diode display and the manufacturing method thereof disclosed in the above embodiments of the present invention, because the first transparent extension electrode and the second transparent extension electrode are formed after the first light emitting unit, the second light emitting unit, and the third light emitting unit, and then The first light-emitting element, the second light-emitting element, and the third light-emitting element that have formed a transparent extension electrode and a second transparent extension electrode are transferred to the same element substrate, respectively. This will not only increase the difficulty of the process, but also can target different colors of light. The wavelength uses transparent conductive materials with different film thicknesses, thereby improving the light emitting efficiency of the light emitting element. Therefore, the brightness of the display can be made better. In addition, the manufacturing process on the element substrate can be relatively simplified, which is a mass production process. In addition, the material of the first / second transparent extension electrode and the material of the first / second connection electrode may be different transparent conductive materials. By combining the two transparent conductive materials, the light emitting efficiency of the light emitting element can be improved.

In summary, although the present invention has been disclosed as above with the embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims (32)

A manufacturing method of a miniature light emitting diode display includes forming a plurality of first light emitting units, each of the first light emitting units including a first electrode and a second electrode, wherein each of the first light emitting units has a first side wall, A second side wall and an insulating layer, the first electrode is adjacent to the first side wall and the second electrode is adjacent to the second side wall, the insulating layer covers the first side wall and the second side wall; forming a plurality of second light emitting units, Each of the second light-emitting units includes a first electrode and a second electrode, wherein each of the second light-emitting units has a first side wall, a second side wall, and an insulating layer, and the first electrode is adjacent to the first side wall and the A second electrode is adjacent to the second side wall, and the insulating layer covers the first side wall and the second side wall; a first transparent extension electrode and a second transparent extension electrode are formed on the first side wall of each of the first light emitting units, respectively. The first electrode and the second electrode of the first light-emitting unit corresponding to the insulating layer of the second sidewall are electrically connected respectively to form a plurality of first light-emitting elements. For emitting a first color light, wherein the first transparent extension electrode and the second transparent extension electrode of each of the first light emitting elements have a first film thickness T1; a first transparent extension electrode and a second The transparent extension electrode is on the first side wall and the insulating layer of the second side wall of each of the second light emitting units, and the first electrode and the second electrode of the corresponding second light emitting unit are electrically connected respectively, and Forming a plurality of second light emitting elements for emitting a second color light different from the first color light, wherein the first transparent extension electrode and the second transparent extension electrode of each of the second light emitting elements have a second Film thickness T2, the second film thickness T2 is different from the first film thickness T1; the first light emitting elements and the second light emitting elements are disposed on an element substrate having a plurality of first pads and A plurality of second connection pads; and a plurality of first connection electrodes and a plurality of second connection electrodes are formed on the element substrate, and each of the first connection electrodes is electrically connected to the corresponding first transparent extension electrode and the corresponding first connection electrode. Pads The second connection electrodes are electrically connected to the corresponding second transparent extension electrodes and the corresponding second pads. The manufacturing method according to item 1 of the scope of patent application, wherein the first film thickness T1 is between 2000 angstroms and 2300 angstroms, and the second film thickness T2 is between 200 angstroms and 500 angstroms. The manufacturing method according to item 2 of the scope of the patent application, wherein the first connection electrode and the second connection electrode have an electrode film thickness d, and the electrode film thickness d is between 500 angstroms and 800 angstroms. The production method described in item 3 of the scope of patent application, where 1.4 <(T1 + d) / (T2 + d) <2.8. The manufacturing method according to item 2 of the scope of patent application, wherein the first color light emitted by the first light-emitting element has a main wavelength range of 480 nm to 750 nm, and the second color light emitted by the second light-emitting element has A dominant wavelength range is 380nm to 480nm. The manufacturing method according to item 1 of the scope of patent application, further comprising: forming a plurality of third light-emitting units, each of the third light-emitting units including a first electrode and a second electrode, wherein each of the third light-emitting units has a first A side wall, a second side wall, and an insulating layer, the first electrode is adjacent to the first side wall and the second electrode is adjacent to the second side wall, and the insulating layer covers the first side wall and the second side wall; A transparent extension electrode and a second transparent extension electrode are on the first side wall and the insulation layer of the second side wall of each of the third light emitting units, and are electrically connected to the first of the corresponding third light emitting units respectively. An electrode and the second electrode to form a plurality of third light emitting elements for emitting a third color light, wherein the colors of the first color light, the second color light, and the third color light are different; The light emitting element is disposed on the element substrate, wherein the first transparent extension electrode and the second transparent extension electrode of each of the third light emitting elements have a third film thickness T3, which is different from the second film Thick T2 And the third film thickness T3 is between 2000 angstroms and 2300 angstroms. The manufacturing method according to item 1 of the scope of patent application, wherein the materials of the first transparent extension electrode and the second transparent extension electrode corresponding to the first light emitting element and the material corresponding to the second light emitting element are different. The manufacturing method according to item 1 of the scope of patent application, wherein the material of the first transparent extension electrode and the second transparent extension electrode is indium tin oxide (ITO), indium zinc oxide (IZO), conductive polymer, nanometer Carbon tube or nano metal. The manufacturing method according to item 1 of the scope of patent application, wherein the materials of the first transparent extension electrode and the second transparent extension electrode and the materials of the first connection electrode and the second connection electrode are different transparent conductive materials. The manufacturing method according to item 1 of the scope of patent application, wherein the material of the first connection electrode and the second connection electrode is indium tin oxide (ITO), indium zinc oxide (IZO), a conductive polymer, and a carbon nanotube. Or nano metal. The manufacturing method according to item 1 of the scope of patent application, wherein a material of the first connection electrode and the second connection electrode is metal. The manufacturing method according to item 1 of the scope of patent application, wherein the width of the first connection electrode and the second connection electrode is greater than the width of the first transparent extension electrode and the second transparent extension electrode by at least twice. The manufacturing method according to item 1 of the scope of patent application, wherein before forming the first transparent extension electrodes and the second transparent extension electrodes, the method further includes: transferring the first light emitting units to a first transition substrate; And transferring the second light emitting units to a second transition substrate. A miniature light-emitting diode includes a light-emitting unit including a first electrode, a light-emitting structure, and a second electrode. The light-emitting unit has a first side wall, a second side wall, and an insulating layer. The first electrode is adjacent to the first side wall and the second electrode is adjacent to the second side wall; the insulating layer covers the first side wall and the second side wall; and a first transparent extension electrode and a second transparent extension electrode are formed, A light emitting element is formed on the insulating layer of the first side wall and the second side wall of the light emitting unit, and the first electrode and the second electrode are electrically connected to form a light emitting element for emitting a color light. A transparent extension electrode and the second transparent extension electrode have a first film thickness; wherein if the color light emitted by the light-emitting element has a main wavelength range of 480 nm to 750 nm, the first film thickness is between 2000 Angstroms and 2300 Angstroms. And if the colored light emitted by the light-emitting element has a main wavelength range of 380 nm to 480 nm, the first film thickness is between 200 angstroms and 500 angstroms. A miniature light emitting diode display includes: an element substrate having a plurality of first pads and a plurality of second pads; a plurality of first light emitting elements disposed on the element substrate, and the first light emitting elements are used for the first light emitting elements. To emit a first color light; a plurality of second light emitting elements are disposed on the element substrate, the second light emitting elements are used to emit a second color light, the first color light is different from the color of the second color light Each of the first and second light-emitting elements includes: a first electrode; a second electrode; and a first transparent extension electrode and a second transparent extension electrode, wherein the first transparent extension electrode is electrically connected to the first An electrode, the second transparent extension electrode is electrically connected to the second electrode, and the first transparent extension electrode and the second transparent extension electrode of each of the first light emitting elements have a first film thickness, and each of the second light emitting elements The first transparent extension electrode and the second transparent extension electrode of the element have a second film thickness, the first film thickness is different from the second film thickness; and a plurality of first connection electrodes and a plurality of second connection electrodes , The first and second light-emitting elements are respectively arranged, wherein each of the first connection electrodes is electrically connected to the corresponding first transparent extension electrode and the corresponding first pad, and each of the second connection electrodes is electrically connected. The corresponding second transparent extension electrodes are correspondingly connected to the corresponding second pads. The display according to item 15 of the scope of patent application, wherein the first film thickness is between 2000 angstroms and 2300 angstroms, and the second film thickness is between 200 angstroms and 500 angstroms. The display according to item 15 of the scope of patent application, wherein the first color light emitted by each of the first light emitting elements has a main wavelength range of 480 nm to 750 nm, and the second color light emitted by each of the second light emitting elements It has a dominant wavelength range from 380nm to 480nm. The display according to item 15 of the scope of patent application, further comprising a plurality of third light emitting elements disposed on the element substrate. The third light emitting elements are used to emit a third color light, the first color light, the first light The color of the two-color light is different from that of the third color light. The first transparent extension electrode and the second transparent extension electrode of each third light-emitting element have a third film thickness, and the third film thickness is different from the second film thickness. And the third film thickness is between 2000 angstroms and 2300 angstroms. The display according to item 18 of the scope of patent application, wherein the first connection electrode and the second connection electrode have an electrode film thickness, and the electrode film thickness is between 500 angstroms and 800 angstroms. The display according to item 18 of the scope of patent application, wherein the width of the first connection electrode and the second connection electrode is at least two times greater than the width of the first transparent extension electrode and the second transparent extension electrode. The display device according to item 15 of the scope of patent application, wherein each of the first connection electrodes and the corresponding electrically connected first electrodes do not overlap in a direction perpendicular to the direction projected on the element substrate, and each of the second connection electrodes and The second electrodes corresponding to the electrical connections do not overlap in a direction perpendicular to the element substrate. The display according to item 15 of the scope of patent application, wherein each of the first connection electrodes and the corresponding first transparent extension electrode are overlapped on the first side wall of the corresponding light emitting element, and each of the second connection electrodes and the corresponding The second transparent extension electrode is overlapped on the second side wall of the corresponding light emitting element. The display according to item 15 of the scope of patent application, wherein each of the first and second light-emitting elements further includes: a light-emitting unit including a first semiconductor layer, an active layer, and a second semiconductor layer. The active layer is located at Between the first semiconductor layer and the second semiconductor layer, wherein the first semiconductor layer has an exposed portion, and the light-emitting unit has a first side wall and a second side wall, and the first side wall is located on one side of the light-emitting unit The second side wall is located on the other side of the light emitting unit; and an insulating layer covering the first side wall and the second side wall of the light emitting unit, wherein the first electrode is disposed on the second semiconductor layer, the A second electrode is disposed on the exposed portion of the first semiconductor layer. The display according to item 23 of the scope of patent application, wherein each of the first connection electrodes and the corresponding first transparent extension electrode overlap with the corresponding active layer in a direction parallel to the element substrate. A manufacturing method of a miniature light emitting diode includes forming a first semiconductor layer, an active layer, and a second semiconductor layer on a substrate. The active layer is located between the first semiconductor layer and the second semiconductor layer. ; Patterning the first semiconductor layer, the active layer, and the second semiconductor layer to form a plurality of light emitting structures; removing a portion of the second semiconductor layer and a portion of the active layer above the first semiconductor layer in each of the light emitting structures Layer to form a plurality of light-emitting units of the first semiconductor layer having an exposed portion; forming an insulating layer on each of the light-emitting units, wherein each of the light-emitting units includes a first side wall and a second side wall, the first The side wall is located on one side of each of the light emitting units, the second side wall is located on the other side of each of the light emitting units, and the insulating layer covers the first side wall and the second side wall of each of the light emitting units; a first electrode is formed respectively On the second semiconductor layer of each light-emitting unit; forming a second electrode on the exposed portion of the first semiconductor layer of each of the light-emitting units; and separately forming A first transparent extension electrode and a second transparent extension electrode are on the insulating layer of each of the light emitting units. Each of the first transparent extension electrodes is electrically connected to the first electrode of the corresponding light emitting unit, and each of the second transparent extension electrodes. An electrode is electrically connected to the second electrode of the corresponding light-emitting unit to form a plurality of light-emitting elements. The first transparent extension electrode and the second transparent extension electrode have a first film thickness, and the first film thickness is between 2000 and 2000. Angstroms to 2300 angstroms, and the first color light emitted by the light-emitting elements has a main wavelength range of 480 nm to 750 nm. A manufacturing method of a miniature light emitting diode includes forming a first semiconductor layer, an active layer, and a second semiconductor layer on a substrate. The active layer is located between the first semiconductor layer and the second semiconductor layer. ; Patterning the first semiconductor layer, the active layer, and the second semiconductor layer to form a plurality of light emitting structures; removing a portion of the second semiconductor layer and a portion of the active layer above the first semiconductor layer in each of the light emitting structures Layer to form a plurality of light-emitting units of the first semiconductor layer having an exposed portion; forming an insulating layer on each of the light-emitting units, wherein each of the light-emitting units includes a first side wall and a second side wall, the first The side wall is located on one side of each of the light emitting units, the second side wall is located on the other side of each of the light emitting units, and the insulating layer covers the first side wall and the second side wall of each of the light emitting units; a first electrode is formed respectively On the second semiconductor layer of each light-emitting unit; forming a second electrode on the exposed portion of the first semiconductor layer of each of the light-emitting units; and separately forming A first transparent extension electrode and a second transparent extension electrode are on the insulating layer of each of the light emitting units. Each of the first transparent extension electrodes is electrically connected to the first electrode of the corresponding light emitting unit, and each of the second transparent extension electrodes. An electrode is electrically connected to the second electrode of the corresponding light-emitting unit to form a plurality of light-emitting elements. The first transparent extension electrode and the second transparent extension electrode have a first film thickness, where the first film thickness is between 200 and 200. Angstroms to 500 angstroms, and the first color light emitted by the first light emitting element has a main wavelength range of 380 nm to 480 nm. A manufacturing method of a miniature light emitting diode display includes: providing a plurality of first light emitting elements and a plurality of second light emitting elements, the first light emitting elements are used for emitting a first color light, and the second light emitting elements are used for To emit a second color light, the first color light is different from the second color light; forming a first transparent extension electrode and a second transparent extension electrode on each of the first light emitting element and each of the second light emitting element, respectively Wherein the first transparent extension electrode and the second transparent extension electrode of each of the first light emitting elements have a first film thickness, and the first transparent extension electrode and the second transparent extension electrode of each of the second light emitting elements have A second film thickness, the first film thickness being different from the second film thickness; transferring the first light-emitting elements and the second light-emitting element parts to a circuit substrate, the circuit substrate having a corresponding A light emitting element and a first pad and a second pad of each of the second light emitting elements; and forming a first connection electrode and a second connection electrode on each of the first light emitting element and each of the second light emitting element yuan Each of the first connection electrodes is electrically connected to the first transparent extension electrode corresponding to the first light emitting element or the second light emitting element and the corresponding first pad, and each of the second connection electrodes is electrically connected to correspond to The second transparent extension electrode of the first light-emitting element or the second light-emitting element and the corresponding second pad. The manufacturing method of the micro-light emitting diode display according to item 27 of the scope of the patent application, wherein the width of the first connection electrode and the second connection electrode is greater than the width of the first transparent extension electrode and the second transparent extension electrode At least twice as much. The manufacturing method of the micro-light emitting diode display according to item 27 of the scope of patent application, wherein the material of the first transparent extension electrode and the second transparent extension electrode and the material of the first connection electrode and the second connection electrode For different transparent conductive materials. The manufacturing method of the micro-light emitting diode display according to item 27 of the scope of the patent application, wherein the materials of the first connection electrode and the second connection electrode, the first transparent extension electrode and the second transparent extension electrode are oxidized. Indium tin (ITO), indium zinc oxide (IZO), conductive polymer, nano carbon tube or nano metal. According to the manufacturing method of the miniature light-emitting diode display according to item 27 of the patent application scope, wherein the first transparent extension electrode and the second transparent extension electrode are respectively formed after the light emitting elements, the manufacturing method further includes: Transfer the first light-emitting elements or the second light-emitting elements to a transition substrate, and then transfer the first light-emitting elements or the second light-emitting elements to the circuit substrate. The manufacturing method of the micro-light-emitting diode display according to item 27 of the scope of patent application, wherein before transferring the light-emitting elements to the circuit substrate, the method further includes: transferring the first light-emitting elements to a first transition substrate Step of transferring the second light-emitting elements to a second transition substrate; and forming the first transparent extension electrode and the second transparent extension electrode on each of the light-emitting elements, respectively, including: forming the first transparent electrodes separately. An extension electrode and the second transparent extension electrode on each of the first light-emitting elements of the first transition substrate; and forming the first transparent extension electrode and the second transparent extension electrode on each of the first transition substrates respectively Two light emitting elements.