Light-emitting diode display device

A light-emitting diode display device includes a light-emitting diode and a substrate. The light-emitting diode includes a central axis, and the substrate includes a first connecting portion and a second connecting portion. The central axis is extended through the first connecting portion. The second connecting portion is disposed outside of the first connecting portion and is spaced apart from the first connecting portion by a distance which is greater than zero, and the first connecting portion and the second connecting portion are respectively electrically connected to the light-emitting diode.

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

The present disclosure relates to a light-emitting diode display device, and more particularly to a light-emitting diode display device assembled using fluid self-assembly technology.

Description of the Related Art

An electronic display device is an optoelectronic device capable of transforming electronic signals into a viewable image, so that a viewer can watch the information loaded in the electronic signals. Recently, electronic display devices such as liquid-crystal displays and Organic electroluminescence displays have become very popular.

A micro-light-emitting-diode display is an effective solution to the problem of how to reduce the volume of an electronic display device. In contrast to other types of display devices, the micro-light-emitting-diode display has the advantages of small size, high contrast, low power consumption, and fast response time.

However, the size of the micro-light-emitting diode is very small, so that the main problem in the manufacturing procedure is how to accurately and stably assemble every micro-light-emitting diode on a driving backplane of the display device.

Therefore, how to accurately and stably assemble every micro-light-emitting diode on a driving backplane is an important issue to be studied.

BRIEF SUMMARY OF THE DISCLOSURE

Accordingly, the disclosure provides a light-emitting diode display device, to solve the problems described above.

In some embodiments, the disclosure provides a light-emitting diode display device, including a light-emitting diode and a substrate. The light-emitting diode includes a central axis. The substrate includes a first connecting portion and a second connecting portion. The central axis of the light-emitting diode is extended through the first connecting portion. The second connecting portion is disposed outside of the first connecting portion and is spaced apart from the first connecting portion by a distance which is greater than zero, and the first connecting portion and the second connecting portion are respectively electrically connected to the light-emitting diode.

In some embodiments, the disclosure further provides a light-emitting diode display device including a substrate and a plurality of light-emitting diodes. The substrate includes a plurality of grooves, and an electrical contact is disposed in each of the grooves. The light-emitting diodes are configured to install in the grooves. Each of the light-emitting diodes includes a main body, a first contact, and a second contact. The first contact and the second contact are disposed on the main body, and the first contact and the second contact are respectively electrically connected to the substrate through the corresponding electrical contacts.

The disclosure provides a light-emitting diode display device applied to a display. The light-emitting diode display device includes a substrate having a plurality of grooves and a plurality of micro-light-emitting diodes. Each of the micro-light-emitting diodes can include at least one dielectric layer, so that the micro-light-emitting diode can be driven by an external electric field to move toward the corresponding groove during the fluid self-assembly procedure, so that the micro-light-emitting diode is correctly installed in the corresponding groove. The main body of the micro-light-emitting diode can also be a cuboid or a trapezoid, and the micro-light-emitting diode can be more accurately installed in the corresponding groove on the substrate due to this design.

In addition, a connecting pad in the groove (such as the first connecting portion) corresponding to the positive electrode of the micro-light-emitting diode can be configured to be a circular structure, and a connecting pad in the groove (such as the second connecting portion) corresponding to the negative electrode of the micro-light-emitting diode can be configured to be a ring structure, so that the positive electrode and the negative electrode of the micro-light-emitting diode can correctly contact the corresponding connecting pads when the micro-light-emitting diode is installed in the groove.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

In the following detailed description, for the purposes of explanation, numerous specific details and embodiments are set forth in order to provide a thorough understanding of the present disclosure. The specific elements and configurations described in the following detailed description are set forth in order to clearly describe the present disclosure. It will be apparent, however, that the exemplary embodiments set forth herein are used merely for the purpose of illustration, and the inventive concept may be embodied in various forms without being limited to those exemplary embodiments. In addition, the drawings of different embodiments may use like and/or corresponding numerals to denote like and/or corresponding elements in order to clearly describe the present disclosure. However, the use of like and/or corresponding numerals in the drawings of different embodiments does not suggest any correlation between different embodiments. The directional terms, such as “up”, “down”, “left”, “right”, “front” or “rear”, are reference directions for accompanying drawings. Therefore, using the directional terms is for description instead of limiting the disclosure.

It should be understood that component for specific description or specific figures can be present in any forms with which the skilled person is familiar. In addition, when a layer is “above” other layers or a substrate, it might be “directly” on the layers or the substrate, or some other layers are between the layer and other layers.

In this specification, relative expressions are used. For example, “lower”, “bottom”, “higher” or “top” are used to describe the position of one element relative to another. It should be appreciated that if a device is flipped upside down, an element at a “lower” side will become an element at a “higher” side.

The terms “about” and “substantially” typically mean +/−20% of the stated value, more typically +/−10% of the stated value and even more typically +/−5% of the stated value. The stated value of the present disclosure is an approximate value. When there is no specific description, the stated value includes the meaning of “about” or “substantially”.

Please refer toFIG. 1, which is a diagram of a light-emitting diode display device100according to the first embodiment of the disclosure. In this embodiment, the light-emitting diode display device100includes a substrate102and a plurality of light-emitting diodes200. Only one light-emitting diode200is illustrated in this embodiment for simplicity. Those light-emitting diodes200can be micro-light-emitting-diodes. The substrate102can include a driving circuit layer103, an insulation layer105and a bottom layer107. The driving circuit layer103is disposed on the bottom layer107, and the insulation layer105is disposed on the driving circuit layer103and forms a plurality of grooves. Only two grooves104and106are illustrated in this embodiment for easy explanation. The light-emitting diode200is configured to be installed on the groove104and the groove106, and the light-emitting diode200includes a main body202, a first contact204, a second contact206and a first dielectric layer208. In this embodiment, the main body202is a cube or a cuboid, and the main body202includes a first side2021and a second side2022. The first contact204, the second contact206and the first dielectric layer208are disposed on the same side of the main body202. For example, they can be disposed on the first side2021of the main body202.

During the fluid self-assembly procedure, the light-emitting diode200and the substrate102is immersed in a fluid (not shown in the figures). At this time, the light-emitting diode200is located on a position P1shown inFIG. 1, and the first contact204and the second contact206face upward. When an electric field E1is applied to the light-emitting diode display device100, the first dielectric layer208of the light-emitting diode200is induced and polarized, so that the first dielectric layer208correspondingly generates positive charges. Therefore, the polarized light-emitting diode200is driven by the electric field E1to flip around the X axis to a position P2, and the light-emitting diode200continues to move toward the substrate102. After that, the first contact204and the second contact206can be respectively joined with the groove104and the groove106, so that the light-emitting diode200is installed on the substrate102. At this time, the first contact204and the second contact206are respectively in contact with two electrical pads in the groove104and the groove106, so that first contact204and the second contact206are electrically connected to the driving circuit layer103via the two electrical pads.

Please refer toFIG. 2, which is a diagram of a light-emitting diode display device100A according to the second embodiment of the disclosure. In contrast to the first embodiment, the light-emitting diode200A of the light-emitting diode display device100A further includes a second dielectric layer210, and the first dielectric layer208and the second dielectric layer210are disposed on opposite sides of the main body202. For example, the first dielectric layer208is disposed on the first side2021of the main body202, and the second dielectric layer210is disposed on the second side2022of the main body202. The first dielectric layer208and the second dielectric layer210have different dielectric constants. In this embodiment, the dielectric constant of the first dielectric layer208is greater than the dielectric constant of the second dielectric layer210.

During the fluid self-assembly procedure, the light-emitting diode200A is originally located on the position P1shown inFIG. 2, and the first contact204and the second contact206face upward. When an electric field E1is applied to the light-emitting diode display device100A, the first dielectric layer208and the second dielectric layer210of the light-emitting diode200A are induced and polarized, so that the first dielectric layer208correspondingly generates positive charges, and the second dielectric layer210correspondingly generates negative charges. Therefore, the polarized light-emitting diode200A is driven by the electric field E1to flip around the X axis to the position P2, and the light-emitting diode200continues to move toward the substrate102. After that, the first contact204and the second contact206can be respectively joined with the groove104and the groove106, so that the light-emitting diode200A is installed on the substrate102.

Please refer toFIG. 3andFIG. 4, which are diagrams of a light-emitting diode display device100B according to the third embodiment of the disclosure. In contrast to the light-emitting diode200A of the second embodiment, the light-emitting diode200B in this embodiment includes the first contact204and the second contact206with different diameters, and the substrate102includes the groove104and the groove106respectively corresponding to the first contact204and the second contact206. In this embodiment, the diameter DC1of the first contact204is greater than the diameter DC2of the second contact206. Furthermore, the light-emitting diode200B further includes a third dielectric layer212and a fourth dielectric layer214. The third dielectric layer212is disposed between the main body202and the first contact204, the fourth dielectric layer214is disposed between the main body202and the second contact206, and the third dielectric layer212and the fourth dielectric layer214have different dielectric constants. For example, the dielectric constant of the third dielectric layer212is greater than the dielectric constant of the fourth dielectric layer214.

As shown inFIG. 3, the light-emitting diode200B is located in the position P1. At this time, the first contact204with a large diameter faces the groove104with a small size, and the second contact206with a small diameter faces the groove106with a large size. In order to install the light-emitting diode200B on the substrate102, an electric field E2is applied to the light-emitting diode display device100B, so that the third dielectric layer212and the fourth dielectric layer214of the light-emitting diode200B are induced and polarized due to the electric field E2, and then the third dielectric layer212correspondingly generates positive charges, and the fourth dielectric layer214correspondingly generates negative charges. Therefore, the polarized light-emitting diode200B is driven by the electric field E2to rotate along the XY plane or flip around the Y axis to the position P2shown inFIG. 4.

After that, the electric field E2is turned off and the electric field E1is turned on inFIG. 4, so that the first dielectric layer208and the second dielectric layer210of the light-emitting diode200B are induced and polarized. The first dielectric layer208correspondingly generates positive charges, and the second dielectric layer210correspondingly generates negative charges. Therefore, the polarized light-emitting diode200B is driven to move along the Y axis toward the substrate102, so that the first contact204and the second contact206can be respectively joined with the groove104and the groove106. As a result, the light-emitting diode200B is installed on the substrate102.

Please refer toFIG. 5, which is a bottom view of a light-emitting diode200C in a flow path according to the fourth embodiment of the disclosure. The structure of the light-emitting diode200C is similar to the light-emitting diode200inFIG. 1, the difference between the two light-emitting diodes200and200C is that the main body202of the light-emitting diode200C is a trapezoidal structure. The first side2021is a trapezoidal surface in a bottom view, and the first contact204, the second contact206and the first dielectric layer208are disposed on the first side2021. Similarly, the second side2022is also a trapezoidal surface from a top view.

When the light-emitting diode200C is disposed in the fluid in the flow path and the flow direction is along the arrows inFIG. 5, the trapezoidal structure of the main body202can help the light-emitting diode200C to stably flow along the direction of the fluid and the light-emitting diode200C does not rotate or drift. In addition, in other embodiment, the light-emitting diode200C can also has the first contact204and the second contact206with different diameters.

Please refer toFIG. 6, which is a diagram of a light-emitting diode display device100D according to the fifth embodiment of the disclosure. In this embodiment, a light-emitting diode200D of the light-emitting diode display device100D is configured to join with the groove104of the substrate102, and the main body202of the light-emitting diode200D includes the first side2021and the second side2022. The first dielectric layer208and the first contact204are disposed on the first side2021, and the second dielectric layer210and the second contact206are disposed on the second side2022. The first dielectric layer208and the second dielectric layer210can have different dielectric constants. For example, the dielectric constant of the first dielectric layer208is greater than the dielectric constant of the second dielectric layer210.

When the electric field E1is applied to the light-emitting diode display device100D, the first dielectric layer208and the second dielectric layer210of the light-emitting diode200D are induced and polarized, so that the first dielectric layer208correspondingly generates positive charges, and the second dielectric layer210correspondingly generates negative charges. Therefore, the polarized light-emitting diode200D is driven by the electric field E1to move toward the groove104, so that the first contact204can join with the groove104.

Please refer toFIG. 7, which is a diagram of a light-emitting diode display device100E according to the sixth embodiment of the disclosure. In this embodiment, the structure of the light-emitting diode200E of the light-emitting diode display device100E is similar to the light-emitting diode200D of the fifth embodiment, the difference is that the main body202of the light-emitting diode200E is a trapezoidal body. The first side2021and the second side2022of the main body202are rectangular surfaces and are parallel to each other. The first dielectric layer208and the first contact204are disposed on the first side2021, and the second dielectric layer210and the second contact206are disposed on the second side2022. The first dielectric layer208and the second dielectric layer210can have different dielectric constants.

For example, when it is desired to join the second contact206with the corresponding groove104using the electric field E1, the dielectric constant of the second dielectric layer210needs to be greater than the dielectric constant of the first dielectric layer208. In addition, when it is desired to join the first contact204with the corresponding groove106using the electric field E1, the dielectric constant of the first dielectric layer208needs to be greater than the dielectric constant of the second dielectric layer210.

Please refer toFIG. 8, which is a diagram of a light-emitting diode display device100F according to the seventh embodiment of the disclosure. In this embodiment, the light-emitting diode display device100F can be a sub-pixel of one pixel in a display panel, and the light-emitting diode display device100F includes a light-emitting diode200F, a light-emitting diode200G and a light-emitting diode200H. The contact areas of the light-emitting diode200F, light-emitting diode200G and light-emitting diode200H with the driving circuit layer103are different. They can emit light beams with the same wavelength, or they can be different light-emitting diodes respectively emitting light beams with different wavelengths, such as red light, green light or blue light. The structures of the light-emitting diode200F, light-emitting diode200G and light-emitting diode200H are similar to the light-emitting diode200D in the fifth embodiment, and the substrate102includes a groove104, a groove106and a groove108corresponding to the light-emitting diodes200F,200G and200H.

During the fluid self-assembly procedure, the order of installing the light-emitting diodes200F,200G and200H on the corresponding grooves104,106and108is according to their size (from the smallest one to the biggest one). For example, the light-emitting diode200H corresponding to the bigger groove108is installed on the groove108at first, and then the light-emitting diode200G is installed on the groove106. Finally, the light-emitting diode200F with the smallest size is installed on the groove104. This order of installation can prevent the light-emitting diode from being installed on a wrong groove in the procedure of installation. For example, if the light-emitting diode200G is installed first, then the light-emitting diode200G may join with the groove108instead of the corresponding groove106.

It should be noted that, because the sub-pixel (the light-emitting diode display device100F) includes three light-emitting diodes200F,200G and200H, if one of the light-emitting diodes is broken, the remaining two light-emitting diodes can serve as substitutes for the broken one and continue to emit light beams.

Please refer toFIG. 9, which is a diagram of a first driving circuit110according to one embodiment of the disclosure. The driving circuit layer103includes a plurality of first driving circuits110, configured to drive the light-emitting diodes. Each of the first driving circuits110includes a first transistor M1, a second transistor M2, a third transistor M3, and a fourth transistor M4. A first terminal of the first transistor M1is electrically connected to a first direct-current voltage VDD, a second terminal of the first transistor M1is electrically connected to an electrical contact EC1, and a control terminal of the first transistor M1is electrically connected to a first driving signal EM1. A control terminal of the second transistor M2is electrically connected to a second driving signal EM2, a first terminal of the second transistor M2is electrically connected to the second terminal of the first transistor M1, and a second terminal of the second transistor M2is electrically connected to a second direct-current voltage VSS.

A control terminal of the third transistor M3is electrically connected to the second driving signal EM2, a first terminal of the third transistor M3is electrically connected to the first direct-current voltage VDD, and a second terminal of the third transistor M3is electrically connected to an electrical contact EC2. A control terminal of the fourth transistor M4is electrically connected to the first driving signal EM1, a first terminal of the fourth transistor M4is electrically connected to the second terminal of the third transistor M3, and a second terminal of the fourth transistor M4is electrically connected to the second direct-current voltage VSS. The first direct-current voltage VDD is greater than the second direct-current voltage VSS, and the first driving signal EM1and the second driving signal EM2are square wave signals and complementary signals.

Take the first embodiment for example, the electrical contact EC1can be an electrical contact disposed in the groove104, and the electrical contact EC2can be an electrical contact in the groove106. The first contact204of the light-emitting diode200can be the positive electrode configured to be electrically connected to the electrical contact EC1, and the second contact206can be the negative electrode configured to be electrically connected to the electrical contact EC2. In this configuration, when the first driving signal EM1is at a high voltage level, the first transistor M1and the fourth transistor M4are turned on, so as to drive the light-emitting diode200to emit the light.

Conversely, during the fluid self-assembly procedure, the positive electrode (first contact204) of the light-emitting diode200may be electrically connected to the electrical contact EC2, and the negative electrode (second contact206) may be electrically connected to the electrical contact EC1. In this configuration, when the second driving signal EM2is at a high voltage level, the third transistor M3and the second transistor M2are turned on, so that the light-emitting diode200is driven to emit the light. It can be known according to the description above that when the first contact204and the second contact206of the light-emitting diode200are respectively electrically connected to the electrical contact EC1and the electrical contact EC2, the light-emitting diode200is driven by the first driving circuit110to emit the light, and when the first contact204and the second contact206are respectively electrically connected to the electrical contact EC2and the electrical contact EC1, the light-emitting diode200is driven by the first driving circuit110to emit the light as well.

Please refer toFIG. 10, which is a diagram of a second driving circuit120according to another embodiment of the disclosure. In this embodiment, the driving circuit layer103can include a plurality of second driving circuits120, configured to drive the light-emitting diodes. Each of the second driving circuits120includes a fifth transistor M5which has a control terminal, a first terminal and a second terminal. The control terminal of the fifth transistor M5is electrically connected to a driving signal EM, the first terminal of the fifth transistor M5is electrically connected to a direct-current voltage (such as the second direct-current voltage VSS), the second terminal of the fifth transistor M5is electrically connected to the electrical contact EC1, and the electrical contact EC2is electrically connected to an alternating-current voltage AC.

Similarly, take the first embodiment for example, the electrical contact EC1can be an electrical contact disposed in the groove104, and the electrical contact EC2can be an electrical contact in the groove106. The first contact204of the light-emitting diode200can be the positive electrode configured to be electrically connected to the electrical contact EC1, and the second contact206can be the negative electrode configured to be electrically connected to the electrical contact EC2. In this configuration, when the driving signal EM is at a high voltage level and the second direct-current voltage VSS is greater than a voltage level of the alternating-current voltage AC, the fifth transistor M5is turned on, so as to drive the light-emitting diode200to emit the light.

Conversely, during the fluid self-assembly procedure, the positive electrode (first contact204) of the light-emitting diode200may be electrically connected to the electrical contact EC2, and the negative electrode (second contact206) may be electrically connected to the electrical contact EC1. In this configuration, when the driving signal EM is at a high voltage level and the second direct-current voltage VSS is less than the voltage level of the alternating-current voltage AC, the fifth transistor M5is turned on, so that the light-emitting diode200is driven to emit the light. It can be known according to the description above that when the first contact204and the second contact206of the light-emitting diode200are respectively electrically connected to the electrical contact EC1and the electrical contact EC2, the light-emitting diode200is driven by the second driving circuit120to emit the light, and when the first contact204and the second contact206are respectively electrically connected to the electrical contact EC2and the electrical contact EC1, the light-emitting diode200is driven by the second driving circuit120to emit the light as well.

Please refer toFIG. 11, which is a diagram of a light-emitting diode display device100I according to the eighth embodiment of the disclosure. In this embodiment, the light-emitting diode200I can include a plurality of light-emitting diodes200I and a substrate102A. Only one light-emitting diode200I and a groove104A on the substrate102A are illustrated inFIG. 11for simplicity. The light-emitting diode200I includes a first contact204and a second contact206. The first contact204is disposed on the bottom of the light-emitting diode200I, and the central axis C of the light-emitting diode200I is extended through the first contact204. The second contact206is disposed on the bottom of the light-emitting diode200I and is spaced apart from the central axis C by a distance. In this embodiment, the first contact204is the positive electrode of the light-emitting diode200I, and the width of the first contact204can be 13 μm, but it is not limited thereto. The second contact206is disposed on two sides of the first contact204, and the width of the second contact206can be 9 μm. The distance between the second contact206and the first contact204is 4 μm, but it is not limited thereto.

Please refer toFIG. 11andFIG. 12.FIG. 12is a top view of the substrate102A and the groove104A inFIG. 11. The substrate102A can include a metal layer101, an insulation layer105, a bottom layer107and a side wall structure109. The metal layer101is disposed on the bottom layer107and is electrically connected to a driving circuit (not shown in the figures), and the insulation layer105is disposed on the metal layer101. The side wall structure109can form the groove104A, which is on the insulation layer105to contain the light-emitting diode200I. A first connecting portion112and a second connecting portion114are disposed in the groove104A. As shown inFIG. 12, when viewed along the central axis C, the first connecting portion112is a circular structure and is positioned on the center of the groove104A. The second connecting portion114is a ring structure which surrounds the first connecting portion112. The first connecting portion112is configured to be electrically connected to the first contact204, and the second connecting portion114is configured to be electrically connected to the second contact206. In this embodiment, the distance between the first connecting portion112and the second connecting portion114can be 7.3 μm, but it is not limited thereto.

In addition, the substrate102A further includes a first through hole116and a second through hole118. The first through hole116penetrates the insulation layer105, and a conductive material is disposed in the first through hole116, such as titanium, but it is not limited thereto. The first through hole116is configured to be electrically connected to the first connecting portion112and the metal layer101. The second through hole118penetrates the insulation layer105, and a conductive material is disposed in the second through hole118, such as titanium. The second through hole118is configured to be electrically connected to the second connecting portion114and the metal layer101. In this embodiment, the center of curvature of the first connecting portion112is located in the first through hole116. The second through hole118is a ring structure when viewed along the central axis C (as shown inFIG. 12). The width W2of the second through hole118is less than the width W1of the second connecting portion114, and the second through hole118is close to the outside of the second connecting portion114.

During the fluid self-assembly procedure, the light-emitting diode200I enters the groove104A, so that the first contact204and the second contact206are respectively in contact with the first connecting portion112and the second connecting portion114. As a result, the light-emitting diode200I can be electrically connected to the driving circuit (not shown in the figures), so that the driving circuit drives the light-emitting diode200I to emit the light.

It should be noted that the diameter D1(such as 45.7 μm) of the groove104A is greater than the diameter D2(such as 41 μm) of the light-emitting diode200I. Therefore, when the light-emitting diode200I enters the groove104A, the central axis C of the light-emitting diode200I may diverge from the central axis C1of the groove104A. However, because of the structural design of this embodiment, the first contact204and the second contact206can still be respectively connected to the first connecting portion112and the second connecting portion114, and the first contact204does not contact the second connecting portion114and the second contact206does not contact the first connecting portion112.

Please refer toFIG. 13andFIG. 14.FIG. 13is a diagram of a light-emitting diode display device100J according to the ninth embodiment of the disclosure.FIG. 14is a top view of the substrate102A and the groove104A inFIG. 13. The structure of the light-emitting diode display device100J in this embodiment is similar to the structure of the light-emitting diode display device100I in the eighth embodiment. The difference is that the first through hole116and the conductive material thereof are ring structures when viewed along the central axis C, which are configured to surround the first connecting portion112. The contact area of the first contact204of the light-emitting diode200I and the first connecting portion112is increased due to this structural design, so as to increase the transmission efficiency of signals between the light-emitting diode200I and the driving circuit.

Please refer toFIG. 15andFIG. 16.FIG. 15is a top view of the substrate102A and the groove104A according to the tenth embodiment of the disclosure.FIG. 16is a sectional view along line A-A′ inFIG. 15. The structure of the light-emitting diode display device100K inFIG. 16is similar to the structure of the light-emitting diode display device100I in the eighth embodiment. The difference is that the first connecting portion112includes a circular portion1121and a protruding portion1122which are connected to each other. The second connecting portion114and the second through hole118are arc structures when viewed along the central axis C, and the angle of the arc structures relative to the central axis C is greater than 180 degrees. Furthermore, as shown inFIG. 15, the protruding portion1122protrudes from the circular portion1121toward a notch in the arc structure, and the first through hole116is disposed under the protruding portion1122. The contact area of the first contact204of the light-emitting diode200I and the first connecting portion112is increased due to this structural design, so as to increase the transmission efficiency of signals between the light-emitting diode200I and the driving circuit.

Please refer toFIG. 17, which is a sectional view of a substrate102B according to the eleventh embodiment of the disclosure. In this embodiment, the substrate102B includes an active area A1and a non-active area A2. The plurality of grooves104A are formed in the active area A1, and the substrate102B further includes a ramp structure S disposed adjacent to a boundary of the non-active area A2and the active area A1. During the fluid self-assembly procedure, the light-emitting diodes are guided by the ramp structure S to smoothly move from the non-active area A2to the active area A1, and then the light-emitting diodes enter the grooves104A.

Please refer toFIG. 18, which is a sectional view of a substrate102C according to the twelfth embodiment of the disclosure. Similar to the eleventh embodiment, the substrate102C includes an active area A1and a non-active area A2. The substrate102C further includes at least one hole H disposed in the non-active area A2of the substrate102C, and the diameter D3of the hole H is less than the diameter (diameter D1) of the groove104A. During the fluid self-assembly procedure, the light-emitting diode moves from the non-active area A2to the active area A1. The diameter of light-emitting diode (such as diameter D2) is slightly less than the diameter D1and greater than the diameter D3of the hole H, so that the light-emitting diode enters the groove104A instead of falling in the hole H when the light-emitting diode moves.

Those light-emitting diode display devices provided in this disclosure can be applied to a display product served as a light source of the display product.

In conclusion, the disclosure provides a light-emitting diode display device applied to a display. The light-emitting diode display device includes a substrate having a plurality of grooves and a plurality of micro-light-emitting diodes. Each of the micro-light-emitting diodes can include at least one dielectric layer, so that the micro-light-emitting diode can be driven by an external electric field to move toward the corresponding groove during the fluid self-assembly procedure, so that the micro-light-emitting diode is correctly installed in the corresponding groove. The main body of the micro-light-emitting diode can also be a cuboid or a trapezoid, and the micro-light-emitting diode can be more accurately installed in the corresponding groove on the substrate due to this structural design.

In addition, a connecting pad in the groove (such as the first connecting portion112) corresponding to the positive electrode of the micro-light-emitting diode can be configured to be a circular structure, and a connecting pad in the groove (such as the second connecting portion114) corresponding to the negative electrode of the micro-light-emitting diode can be configured to be a ring structure, so that the positive electrode and the negative electrode of the micro-light-emitting diode can correctly contact the corresponding connecting pads when the micro-light-emitting diode is installed in the groove.