A light emitting diode display panel and its manufacturing method, and a display device

Abstract

The present invention discloses a light-emitting diode display panel, a method for preparing the same, and a display device. The light-emitting diode display panel includes a substrate, a pixel driving circuit and a light-emitting unit sequentially located on one side of the substrate, the light-emitting unit includes a first electrode, the first electrode includes a first electrode section and a second electrode section connected to each other, the first electrode section is located on the side wall of the light-emitting unit, the light-emitting diode display panel also includes a first connection electrode, the first connection electrode includes a first connection section and a second connection section connected to each other, the plane where the first connection section is located intersects with the plane where the substrate is located, the first connection section is connected to the first electrode section, and the second connection section is connected to the pixel driving circuit. The light-emitting diode display panel, the method for preparing the same, and the display device provided by the embodiments of the present invention reduce the process difficulty and cost by setting the first connection section and the first electrode section to be in contact and connected along the side wall of the light-emitting unit.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of display technology, and in particular to a light emitting diode display panel and a manufacturing method thereof, and a display device. Background Art

[0002] A Micro Light Emitting Diode (Micro LED) display is a display that is made by individually manufacturing Micro LED chips, then transferring them through a mass transfer method and bonding them to a pixel driving circuit on an array substrate. This type of display has the advantages of good display performance, small size, and low power consumption, and has broad application prospects.

[0003] However, in the prior art, the process of bonding Micro LEDs to an array substrate is difficult and costly. Summary of the invention

[0004] The present invention provides a light emitting diode display panel and a manufacturing method thereof, and a display device, so as to reduce the difficulty of the connection process between Micro LED and an array substrate and reduce the cost.

[0005] In a first aspect, an embodiment of the present invention provides a light emitting diode display panel, comprising:

[0006] A substrate, and a pixel driving circuit and a light-emitting unit sequentially located on one side of the substrate;

[0007] The light-emitting unit includes a first electrode; the first electrode includes a first electrode portion and a second electrode portion connected to each other, the first electrode portion is located on the side wall of the light-emitting unit, and the second electrode portion is located on a side of the light-emitting unit close to the substrate;

[0008] The light-emitting diode display panel also includes a first connecting electrode, which includes a first connecting section and a second connecting section that are connected to each other, and a plane where the first connecting section is located intersects with a plane where the substrate is located; the first connecting section is connected to the first electrode section, and the second connecting section is connected to the pixel driving circuit.

[0009] In a second aspect, an embodiment of the present invention further provides a display device, comprising the light emitting diode display panel described in the first aspect.

[0010] In a third aspect, an embodiment of the present invention further provides a method for preparing a light emitting diode display panel, the method comprising:

[0011] Prepare a pixel driving circuit on one side of the substrate;

[0012] A light-emitting unit is prepared on a growth substrate, wherein the light-emitting unit includes a first electrode, wherein the first electrode includes a first electrode portion and a second electrode portion connected to each other, wherein the first electrode portion is located on a side wall of the light-emitting unit, and the second electrode portion is located on a side of the light-emitting unit away from the growth substrate;

[0013] Placing the light-emitting unit on a side of the pixel driving circuit away from the substrate, wherein the second electrode portion is located on a side of the light-emitting unit close to the substrate;

[0014] A first connecting electrode is prepared, wherein the first connecting electrode comprises a first connecting section and a second connecting section connected to each other, wherein a plane where the first connecting section is located intersects with a plane where the substrate is located, the first connecting section is connected to the first electrode section, and the second connecting section is connected to the pixel driving circuit.

[0015] The light-emitting diode display panel and its preparation method and display device provided by the embodiments of the present invention are configured such that the first electrode of the light-emitting unit includes a first electrode portion located on the side wall of the light-emitting unit, the first connection electrode of the light-emitting diode display panel includes a first connection portion intersecting with the plane where the substrate is located, and the first connection portion is configured to be in contact and connected with the first electrode portion along the side wall of the light-emitting unit to realize signal transmission between the pixel driving circuit and the light-emitting unit, so that the first connection electrode can be prepared and connected through a conventional photolithography patterning process, without the need to perform the steps of heating-pressing-bonding the eutectic layer in the prior art, thereby reducing the process difficulty; at the same time, the light-emitting diode display panel does not need to set a eutectic layer with a relatively high cost, thereby reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of a light emitting diode display panel provided by an embodiment of the present invention;

[0017] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure along the A-A' direction;

[0018] Figure 3 A schematic diagram of an enlarged structure of a light-emitting unit provided in an embodiment of the present invention;

[0019] Figure 4 A schematic diagram of an enlarged structure of another light-emitting unit provided in an embodiment of the present invention;

[0020] Figure 5 A schematic diagram of an enlarged structure of another light-emitting unit provided in an embodiment of the present invention;

[0021] Figure 6 A schematic diagram of an enlarged structure of another light-emitting unit provided in an embodiment of the present invention;

[0022] Figure 7 A schematic diagram of an enlarged structure of another light-emitting unit provided in an embodiment of the present invention;

[0023] Figure 8 A schematic diagram of a partial cross-sectional structure of a light emitting diode display panel provided by an embodiment of the present invention;

[0024] Fig. 9 A schematic diagram of a process for preparing a light emitting diode display panel provided by an embodiment of the present invention;

[0025] Fig.10 A schematic diagram of the structure of a display device provided by an embodiment of the present invention;

[0026] Fig.11 A schematic flow chart of a method for preparing a light emitting diode display panel provided by an embodiment of the present invention;

[0027] Fig.12 A schematic diagram of a process for preparing a pixel driving circuit provided by an embodiment of the present invention;

[0028] Fig.13 A schematic diagram of a process for preparing a light-emitting unit provided in an embodiment of the present invention;

[0029] Fig.14 A schematic diagram of a process for placing a light-emitting unit provided in an embodiment of the present invention;

[0030] Fig.15 A schematic diagram of a process for preparing a first insulating layer provided by an embodiment of the present invention;

[0031] Fig.16 A schematic diagram of a process for etching a first insulating layer provided by an embodiment of the present invention;

[0032] Fig.17 A schematic diagram of a process for preparing a connecting electrode layer provided in an embodiment of the present invention;

[0033] Fig.18 A schematic diagram of a process for preparing a first connecting electrode provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0035] Figure 1A schematic diagram of the structure of a light emitting diode display panel provided by an embodiment of the present invention, Figure 2 for Figure 1 The schematic diagram of the cross-sectional structure along the A-A' direction is as follows: Figure 1 and Figure 2 As shown, the light emitting diode display panel provided by the embodiment of the present invention includes a substrate 10, and a pixel driving circuit 11 and a light emitting unit 12 sequentially located on one side of the substrate 10, the light emitting unit 12 includes a first electrode 21; the first electrode 21 includes a first electrode sub-portion 211 and a second electrode sub-portion 212 connected to each other, the first electrode sub-portion 211 is located on the side wall of the light emitting unit 12, and the second electrode sub-portion 212 is located on the side of the light emitting unit 21 close to the substrate 10. The light emitting diode display panel also includes a first connecting electrode 31, the first connecting electrode 31 includes a first connecting sub-portion 311 and a second connecting sub-portion 312 connected to each other, the plane where the first connecting sub-portion 311 is located intersects with the plane where the substrate 10 is located; the first connecting sub-portion 311 is connected to the first electrode sub-portion 211, and the second connecting sub-portion 312 is connected to the pixel driving circuit 11.

[0036] Specifically, Figure 1 and Figure 2 As shown, a plurality of pixel driving circuits 11 and a plurality of light emitting units 12 are provided on one side of the substrate 10. The plurality of light emitting units 12 may be arranged in an array. The pixel driving circuit 11 is used to make the light emitting unit 12 emit light to realize display. The pixel driving circuit 11 may be provided in a one-to-one correspondence with the light emitting unit 12 so that one pixel driving circuit 11 drives a corresponding light emitting unit 12. One pixel driving circuit 11 may also be provided to drive a plurality of light emitting units 12. The embodiment of the present invention is not limited to this.

[0037] Continue to refer Figure 1 and Figure 2 The light-emitting unit 12 can be a micro light-emitting diode (Micro Light Emitting Diode, Micro LED). Micro LED has the advantages of good display performance, small size, low power, etc., and has broad application prospects. In other embodiments, the light-emitting unit 12 can also use other types of light-emitting diodes, such as Mini LED, etc. Those skilled in the art can set it according to actual needs, and the embodiments of the present invention are not limited to this.

[0038] Continue to refer Figure 1 and Figure 2 The first electrode 21 of the light-emitting unit 12 includes a first electrode sub-portion 211 and a second electrode sub-portion 212 connected to each other, the first electrode sub-portion 211 is located on the side wall of the light-emitting unit 12, and the second electrode sub-portion 212 is located on the side of the light-emitting unit 21 close to the substrate 10, and the plane where the first electrode sub-portion 211 is located intersects with the plane where the second electrode sub-portion 212 is located. For example, Figure 2 As shown, the cross-section of the first electrode sub-portion 211 and the second electrode sub-portion 212 is "L" shaped. The first connection electrode 31 of the light emitting diode display panel includes a first connection sub-portion 311 and a second connection sub-portion 312 connected to each other, the plane where the first connection sub-portion 311 is located intersects with the plane where the substrate 10 is located, and the plane where the first connection sub-portion 311 is located intersects with the plane where the second connection sub-portion 312 is located. For example, Figure 2 As shown, excluding the part connected by punching, the plane where the second connection section 312 is located can be parallel to the plane where the substrate 10 is located, and the cross-sections of the first connection section 311 and the second connection section 312 are "L"-shaped.

[0039] Continue to refer Figure 2 By setting the second connection division 312 to be connected to the pixel driving circuit 11, the first connection division 311 is overlapped with the first electrode division 211, so that the driving signal of the pixel driving circuit 11 is transmitted on the path of the second connection division 312-the first connection division 311-the first electrode division 211-the second electrode division 212, thereby driving the light-emitting unit 12 to emit light.

[0040] Compared with the technical solution of bonding the light-emitting unit to the array substrate through a eutectic layer in the prior art, this embodiment realizes that the pixel driving circuit 11 drives the light-emitting unit 12 to emit light by setting the first connection section 311 of the first connection electrode 31 to contact and connect with the first electrode section 211 of the first electrode 21 along the side wall of the light-emitting unit 12 (at this time, the plane where the contact surface of the first connection section 311 and the first electrode section 211 intersects with the plane where the substrate 10 is located), so that the first connection electrode 31 can be prepared and connected through a conventional photolithography patterning process, without the need to perform the steps of heating-pressing-bonding the eutectic layer, thereby reducing the process difficulty; at the same time, in this embodiment, there is no need to set a more expensive eutectic layer, thereby reducing the cost of the light-emitting diode display panel.

[0041] In summary, the light-emitting diode display panel provided by the embodiment of the present invention is provided with a first electrode 21 of the light-emitting unit 12 including a first electrode portion 211 located on the side wall of the light-emitting unit 12, and the first connection electrode 31 of the light-emitting diode display panel includes a first connection portion 311 intersecting with the plane where the substrate 10 is located, and the first connection portion 311 is provided to be in contact and connected with the first electrode portion 211 along the side wall of the light-emitting unit 12 to realize signal transmission between the pixel driving circuit 11 and the light-emitting unit 12, so that the first connection electrode 31 can be prepared and connected by a conventional photolithography patterning process, without the need to perform the steps of heating-pressing-bonding the eutectic layer in the prior art, thereby reducing the process difficulty; at the same time, the light-emitting diode display panel does not need to set a eutectic layer with a higher cost, thereby reducing the cost.

[0042] Continue to refer Figure 1 and Figure 2 Optionally, the light-emitting diode display panel provided in the embodiment of the present invention further includes a first metal layer 13 located on the side of the substrate 10 close to the light-emitting unit 12, and the first metal layer 13 is used to transmit a first power signal. The light-emitting unit 12 further includes a second electrode 22, the second electrode 22 includes a third electrode division 221 and a fourth electrode division 222 connected to each other, the third electrode division 221 is located on the side wall of the light-emitting unit 12, and the fourth electrode division 222 is located on the side of the light-emitting unit 12 close to the substrate 10. The light-emitting diode display panel further includes a second connection electrode 32, the second connection electrode 32 includes a third connection division 321 and a fourth connection division 322 connected to each other, the plane where the third connection division 321 is located intersects with the plane where the substrate 10 is located, the third connection division 321 is connected to the third electrode division 221, and the fourth connection division 322 is connected to the first metal layer 13.

[0043] Specifically, Figure 1 and Figure 2 As shown, the second electrode 22 of the light-emitting unit 12 includes a third electrode division 221 and a fourth electrode division 222 connected to each other, the third electrode division 221 is located on the side wall of the light-emitting unit 12, and the fourth electrode division 222 is located on the side of the light-emitting unit 21 close to the substrate 10. The plane where the third electrode division 221 is located intersects with the plane where the fourth electrode division 222 is located. For example, Figure 2 As shown, the cross-section of the third electrode sub-portion 221 and the fourth electrode sub-portion 222 is "L" shaped. The second connection electrode 32 of the light emitting diode display panel includes a third connection sub-portion 321 and a fourth connection sub-portion 322 connected to each other, the plane where the third connection sub-portion 321 is located intersects with the plane where the substrate 10 is located, and the plane where the third connection sub-portion 321 is located intersects with the plane where the fourth connection sub-portion 322 is located. For example, Figure 2 As shown, excluding the punched connection portion, the plane where the fourth connection portion 322 is located can be parallel to the plane where the substrate 10 is located, and the cross-sections of the third connection portion 321 and the fourth connection portion 322 are "L"-shaped.

[0044] Continue to refer Figure 2 By setting the fourth connection division 322 to be connected to the first metal layer 13, the third connection division 321 is overlapped with the third electrode division 221, so that the first power signal transmitted on the first metal layer 13 is transmitted on the path of the fourth connection division 322-the third connection division 321-the third electrode division 221-the fourth electrode division 222, thereby driving the light-emitting unit 12 to emit light.

[0045] Compared with the technical solution of bonding the light-emitting unit to the array substrate through a eutectic layer in the prior art, this embodiment drives the light-emitting unit 12 to emit light by setting the third connection division 321 of the second connection electrode 32 to contact and connect with the third electrode division 221 of the second electrode 22 along the side wall of the light-emitting unit 12 (at this time, the plane where the contact surface of the third connection division 321 and the third electrode division 221 intersects with the plane where the substrate 10 is located), so that the second connection electrode 32 can be prepared and connected through a conventional photolithography patterning process, without the need to perform the steps of heating-pressing-bonding the eutectic layer, thereby reducing the process difficulty; at the same time, in this embodiment, there is no need to set a more expensive eutectic layer, thereby reducing the cost of the light-emitting diode display panel.

[0046] It should be noted that the first power supply signal may be a PVEE signal, a GND signal or other signals, and those skilled in the art may set it according to actual needs, which is not limited in the embodiments of the present invention.

[0047] Continue to refer Figure 1 and Figure 2 Optionally, the light-emitting unit 12 also includes a first-type semiconductor layer 121, a first active layer 122 and a second-type semiconductor layer 123 which are stacked, the first active layer 122 is located between the first-type semiconductor layer 121 and the second-type semiconductor layer 123, the second electrode portion 212 is connected to the first-type semiconductor layer 121, and the fourth electrode portion 222 is connected to the second-type semiconductor layer 123.

[0048] Among them, Figure 2 As shown, in this embodiment, the second electrode portion 212 at the bottom of the first electrode 21 is connected to the first-type semiconductor layer 121, and the fourth electrode portion 222 at the bottom of the second electrode 22 is connected to the second-type semiconductor layer 123, which helps to increase the contact area between the first electrode 21 and the first-type semiconductor layer 121, and increase the contact area between the second electrode 22 and the second-type semiconductor layer 123, thereby reducing the transmission impedance of the driving signal.

[0049] For example, Figure 2As shown, the first-type semiconductor layer 121 can be a P-type semiconductor layer, and the second-type semiconductor layer 123 can be an N-type semiconductor layer. At this time, the first electrode 21 connected to the first-type semiconductor layer 121 serves as an anode, and the second electrode 22 connected to the second-type semiconductor layer 123 serves as a cathode. When the driving signal of the pixel driving circuit 11 is transmitted along the path of the second connection division 312-first connection division 311-first electrode division 211-second electrode division 212-first-type semiconductor layer 121-first active layer 122-second-type semiconductor layer 123-fourth electrode division 222-third electrode division 221-third connection division 321-fourth connection division 322, the driving signal flows through the first active layer 122, thereby driving the light-emitting unit 12 to emit light.

[0050] It should be noted that the materials of the first-type semiconductor layer 121, the first active layer 122 and the second-type semiconductor layer 123 can be set according to actual needs, for example, they can be materials such as gallium nitride or gallium arsenide. Those skilled in the art can choose different materials according to the different luminous colors of the light-emitting unit 12, and the embodiments of the present invention are not limited to this.

[0051] Figure 3 An enlarged structural diagram of a light emitting unit provided in an embodiment of the present invention is shown in FIG. Figure 3 As shown, optionally, the contact area between the third electrode portion 221 and the third connection portion 321 is greater than the contact area between the first electrode portion 211 and the first connection portion 311 .

[0052] Among them, Figure 3 As shown, by setting the area of ​​the contact surface 431 between the third electrode division 221 and the third connection division 321 to be larger than the area of ​​the contact surface 432 between the first electrode division 211 and the first connection division 311, the contact area between the third electrode division 221 and the third connection division 321 is increased, thereby reducing the impedance between the third electrode division 221 and the third connection division 321, solving the problem of IR drop of the first power supply signal between the third electrode division 221 and the third connection division 321, thereby helping to improve the display uniformity of the light emitting diode display panel.

[0053] It should be noted that, in order to clearly illustrate the positions and sizes of the third electrode sub-portion 221, the third connecting sub-portion 321, the first electrode sub-portion 211 and the first connecting sub-portion 311, Figure 3 for Figure 2 A schematic diagram of the structure of the light emitting unit 12 after being turned upside down.

[0054] Figure 4 Another enlarged structural diagram of a light emitting unit provided in an embodiment of the present invention is shown in FIG. Figure 4As shown, optionally, the third electrode subdivision 221 and the third connection subdivision ( Figure 4 The contact surface 431 between the first electrode portion 211 and the first connection portion (not shown) is located on at least two side walls of the light emitting unit 12. Figure 4 The contact surface 432 between the two (not shown) is located on at least one side wall of the light emitting unit 12.

[0055] Among them, Figure 4 As shown, by setting the third electrode section 221 and the third connection section ( Figure 4 The contact surface 431 between the first electrode portion 211 and the first connection portion (not shown) is located on at least two side walls of the light emitting unit 12. Figure 4 The contact surface 432 between the third electrode division 221 and the third connection division (not shown) is located on at least one side wall of the light-emitting unit 12, so that the contact surface 431 between the third electrode division 221 and the third connection division covers more side walls, thereby further increasing the contact area between the third electrode division 221 and the third connection division, so as to further reduce the impedance between the third electrode division 221 and the third connection division, solve the problem of IR drop of the first power supply signal between the third electrode division 221 and the third connection division 321, and further improve the display uniformity of the light-emitting diode display panel.

[0056] As a feasible implementation method, Figure 4 As shown, the third electrode section 221 and the third connection section ( Figure 4 The contact surface 431 between the first electrode portion 211 and the first connection portion (not shown) is located on the two side walls of the light emitting unit 12. Figure 4 The contact surface 432 between the two (not shown) is located on a side wall of the light emitting unit 12.

[0057] As another possible implementation, Figure 5 A schematic diagram of an enlarged structure of another light-emitting unit provided in an embodiment of the present invention is shown in FIG. Figure 5 As shown, the third electrode section 221 and the third connection section ( Figure 5 The contact surface 431 between the first electrode portion 211 and the first connection portion (not shown) is located on the three side walls of the light emitting unit 12. Figure 5 The contact surface 432 between the two (not shown) is located on a side wall of the light emitting unit 12.

[0058] As another feasible implementation method, Figure 6 A schematic diagram of an enlarged structure of another light-emitting unit provided in an embodiment of the present invention is shown in FIG. Figure 6 As shown, the third electrode section 221 and the third connection section ( Figure 6The contact surface 431 between the first electrode portion 211 and the first connection portion (not shown) is located on the two side walls of the light emitting unit 12. Figure 6 The contact surface 432 between the first electrode portion 211 and the first connection portion (not shown) is located on the two side walls of the light-emitting unit 12, so that the contact surface 432 between the first electrode portion 211 and the first connection portion also covers more side walls, so as to increase the contact area between the first electrode portion 211 and the first connection portion, reduce the impedance between the first electrode portion 211 and the first connection portion, solve the problem of IR drop of the driving signal between the first electrode portion 211 and the first connection portion, and improve the display uniformity of the light-emitting diode display panel.

[0059] Continue to refer Figure 3 Optionally, the first electrode portion 211 and the third electrode portion 221 are respectively located on opposite side walls of the light emitting unit 12 .

[0060] Among them, by arranging the first electrode division 211 and the third electrode division 221 on the opposite side walls of the light-emitting unit 12 respectively, the distance between the first electrode division 211 and the third electrode division 221 is increased, thereby avoiding a short circuit between the first electrode division 211 and the third electrode division 221 and improving the reliability of the light-emitting diode display panel.

[0061] For example, Figure 3 As shown, the first electrode portion 211 and the third electrode portion 221 can be arranged on opposite side walls of the light-emitting unit 12 that are farther away, so as to further increase the distance between the first electrode portion 211 and the third electrode portion 221, thereby avoiding a short circuit between the first electrode portion 211 and the third electrode portion 221 and improving the reliability of the light-emitting diode display panel.

[0062] In other embodiments, Figure 7 A schematic diagram of an enlarged structure of another light-emitting unit provided in an embodiment of the present invention is shown in FIG. Figure 7 As shown, the first electrode section 211 and the third electrode section 221 may be respectively located on opposite side walls of the light emitting unit 12 that are close to each other, thereby increasing the distance between the first electrode section 211 and the third electrode section 221 and also facilitating increasing the distance between the third electrode section 221 and the third connection section ( Figure 7 The area of ​​the contact surface 431 between the first electrode portion 211 and the first connection portion ( Figure 7 The area of ​​the contact surface 432 between the two surfaces (not shown) is reduced, thereby reducing the signal transmission impedance.

[0063] Figure 8 A partial cross-sectional structure diagram of a light emitting diode display panel provided by an embodiment of the present invention is shown in FIG. Figure 8As shown, optionally, the angle between the first electrode portion 211 and the second electrode portion 212 is θ1, where θ1<90°.

[0064] By setting the angle θ1 between the first electrode section 211 and the second electrode section 212 to be less than 90°, the side wall of the light-emitting unit 12 will not be too steep, thereby reducing the possibility of disconnection of the first connecting section 311 and reducing the difficulty of preparing the first connecting section 311.

[0065] It should be noted that the angle θ1 between the first electrode portion 211 and the second electrode portion 212 can be arbitrarily set according to actual needs, for example 45°<θ1<90°, so as to reduce the possibility of disconnection of the first connecting portion 311 while making the preparation of the light-emitting unit 12 not too difficult and easy to implement.

[0066] Furthermore, when the first electrode division 211 is located on at least two side walls of the light-emitting unit 12, the first electrode division 211 includes at least two first sub-divisions, and different first sub-divisions are located on different side walls. By setting the angle between each first sub-division and the second electrode division 212 to be less than 90°, the possibility of disconnection when the first connecting division 311 contacts and connects with each first sub-division is reduced, thereby improving the reliability of the light-emitting diode display panel.

[0067] For example, Figure 6 As shown, the first electrode division 211 is located on the two side walls of the light-emitting unit 12, and the first electrode division 211 includes two first sub-divisions, and different first sub-divisions are located on different side walls, wherein the angle between each first sub-division and the second electrode division 212 is set to be less than 90°, so that the first connection division 311 is easier to connect with the two first sub-divisions, thereby reducing the possibility of disconnection of the first connection division 311.

[0068] Continue to refer Figure 8 Optionally, the angle between the third electrode portion 221 and the fourth electrode portion 222 is θ2, where θ2<90°.

[0069] By setting the angle θ2 between the third electrode portion 221 and the fourth electrode portion 222 to be less than 90°, the side wall of the light-emitting unit 12 will not be too steep, thereby reducing the possibility of disconnection of the third connection portion 321 and reducing the difficulty of preparing the third connection portion 321.

[0070] It should be noted that the angle θ2 between the third electrode division 221 and the fourth electrode division 222 can be arbitrarily set according to actual needs, for example 45°<θ2<90°, so as to reduce the possibility of disconnection of the third connection division 321 while making the preparation of the light-emitting unit 12 not too difficult and easy to implement.

[0071] Furthermore, when the third electrode division 221 is located on at least two side walls of the light-emitting unit 12, the third electrode division 221 includes at least two second sub-divisions, and different second sub-divisions are located on different side walls. By setting the angle between each second sub-division and the fourth electrode division 222 to be less than 90°, the possibility of disconnection when the third connection division 321 contacts and connects with each second sub-division is reduced, thereby improving the reliability of the light-emitting diode display panel.

[0072] For example, Figure 4 As shown, the third electrode division 221 is located on the two side walls of the light-emitting unit 12, and the third electrode division 221 includes two second sub-divisions, and different second sub-divisions are located on different side walls, wherein the angle between each second sub-division and the fourth electrode division 222 is set to be less than 90°, so that the third connection division 321 is easier to connect with the two second sub-divisions, thereby reducing the possibility of disconnection of the third connection division 321.

[0073] In other embodiments, Figure 5 As shown, exemplarily, the third electrode division 221 is located on the three side walls of the light-emitting unit 12, and the third electrode division 221 includes three second sub-divisions, and different second sub-divisions are located on different side walls, wherein the angle between each second sub-division and the fourth electrode division 222 is set to be less than 90°, so that the third connection division 321 is easier to connect with the two second sub-divisions, thereby reducing the possibility of disconnection of the third connection division 321.

[0074] Continue to refer Figure 2 and Figure 8 Optionally, the light emitting diode display panel provided in the embodiment of the present invention further includes a sticky insulating layer 14 located on the side of the substrate 10 facing the light emitting unit 12 , and the sticky insulating layer 14 is in contact with the light emitting unit 12 .

[0075] Specifically, Figure 2 and Figure 8As shown, in the process of preparing the light-emitting diode display panel, the light-emitting unit 12 is first prepared on the growth substrate, and then the light-emitting unit 12 is transferred and released to the side of the pixel driving circuit 11 away from the substrate 10. In this embodiment, a sticky insulating layer 14 in contact with the light-emitting unit 12 is set on the side of the pixel driving circuit 11 away from the substrate 10. When the light-emitting unit 12 is transferred to the sticky insulating layer 14, the light-emitting unit 12 can be fixed by the stickiness of the sticky insulating layer 14, thereby reducing the possibility of movement and dislocation of the light-emitting unit 12, thereby helping to improve the display effect of the light-emitting diode display panel.

[0076] Fig. 9 A schematic diagram of a preparation process of a light emitting diode display panel provided by an embodiment of the present invention is shown in FIG. Fig. 9 As shown, optionally, the light emitting unit 12 is prepared on the growth substrate 44 , and the adhesion between the adhesive insulating layer 14 and the light emitting unit 12 is greater than the adhesion between the light emitting unit 12 and the growth substrate 44 .

[0077] Among them, Fig. 9 As shown, in the process of preparing the light emitting diode display panel, the light emitting unit 12 is first prepared on the growth substrate 44, and then the light emitting unit 12 is transferred to the pixel driving circuit ( Fig. 9 The adhesive insulating layer 14 is not shown in the figure, and is located on a side away from the substrate 10. In this embodiment, by setting the adhesiveness between the adhesive insulating layer 14 and the light-emitting unit 12 to be greater than the adhesiveness between the light-emitting unit 12 and the growth substrate 44, when the light-emitting unit 12 is transferred to the side of the pixel driving circuit away from the substrate 10, the growth substrate 44 on which the light-emitting unit 12 is grown can be directly inverted on the adhesive insulating layer 14, and the light-emitting unit 12 can be peeled off from the growth substrate 44 and adhered to the adhesive insulating layer 14 by utilizing the greater adhesiveness of the adhesive insulating layer 14, thereby improving the transfer efficiency of the light-emitting unit 12. At the same time, this process does not require an additional transfer device to pick up and release the light-emitting unit 12, which simplifies the transfer process and helps to achieve a large-scale transfer of light-emitting units 12 over a large area.

[0078] It should be noted that the embodiment of the present invention does not limit the specific material of the sticky insulating layer 14. The sticky insulating layer 14 may be made of adhesive such as a die-bonding adhesive, or other organic layers with adhesiveness. Those skilled in the art may configure it according to actual needs.

[0079] Meanwhile, the embodiment of the present invention does not limit the specific material of the growth substrate 44 . The growth substrate 44 may be made of a material suitable for epitaxial growth, such as sapphire, and those skilled in the art may configure it according to actual needs.

[0080] Continue to refer Figure 2 and Figure 8Optionally, the light-emitting diode display panel provided in the embodiment of the present invention further includes a first insulating layer 15 , which is located on a side of the substrate 10 close to the light-emitting unit 12 , and the first insulating layer 15 includes a first opening 151 , and the light-emitting unit 12 is located in the first opening 151 .

[0081] Among them, Figure 2 and Figure 8 As shown, by disposing a first insulating layer 15 including a first opening 151 on a side of the substrate 10 close to the light-emitting unit 12 and positioning the light-emitting unit 12 in the first opening 151, the light-emitting unit 12 can be further fixed. At the same time, the first insulating layer 15 can serve as an insulator between adjacent light-emitting units 12 to avoid a short circuit between the second electrode portion 212 and the fourth electrode portion 222 of adjacent light-emitting units 12, thereby improving the reliability of the light-emitting diode display panel.

[0082] For example, Figure 2 and Figure 8 As shown, the first insulating layer 15 can be arranged on the side of the adhesive insulating layer 14 away from the substrate 10. When the light-emitting unit 12 is transferred, the adhesive insulating layer 14 can be used to preliminarily fix the light-emitting unit 12 to prevent the light-emitting unit 12 from sliding, and then the first insulating layer 15 is prepared to further fix the light-emitting unit 12, thereby preventing the light-emitting unit 12 from shaking and improving the stability of the light-emitting diode display panel.

[0083] Continue to refer Figure 2 and Figure 8 Optionally, the light-emitting diode display panel provided in the embodiment of the present invention further includes a first metal layer 13 located on the side of the substrate 10 close to the light-emitting unit 12, and the first metal layer 13 is used to transmit a first power signal. The light-emitting unit 12 further includes a second electrode 22, the second electrode 22 includes a third electrode division 221 and a fourth electrode division 222 connected to each other, the third electrode division 221 is located on the side wall of the light-emitting unit 12, and the fourth electrode division 222 is located on the side of the light-emitting unit 12 close to the substrate 10. The light-emitting diode display panel further includes a second connection electrode 32, the second connection electrode 32 includes a third connection division 321 and a fourth connection division 322 connected to each other, the plane where the third connection division 321 is located intersects with the plane where the substrate 10 is located, the third connection division 321 is connected to the third electrode division 221, and the fourth connection division 322 is connected to the first metal layer 13. The height of the first insulating layer 15 is H1, the height of the second electrode portion 212 is H2, the height of the fourth electrode portion 222 is H3, the height of the first electrode 21 is H5, the height of the second electrode 22 is H6, H4 is the larger one of H2 and H3, and H7 is the smaller one of H5 and H6, wherein H4

[0084] ​Among them, H4 is the larger one between H2 and H3, and H7 is the smaller one between H5 and H6, which means: if H2>H3, then H4=H2; if H2<H3, then H4=H3; if H2=H3, then H4=H2=H3; if H5>H6, then H7=H6; if H5<H6, then H7=H5; if H5=H6, then H7=H5=H6.

[0085] Continue to refer Figure 2 and Figure 3 In this embodiment, the height H1 of the first insulating layer 15 is set to satisfy H4

[0086] Continue to refer Figure 2 and Figure 8 Optionally, a side of the light emitting unit 12 away from the substrate 10 includes an uneven surface.

[0087] Among them, Figure 2 and Figure 8 As shown, by setting the surface of the light-emitting unit 12 away from the substrate 10 to be an uneven surface, the problem of total reflection of the light generated by the light-emitting unit 12 at the interface between the light-emitting unit 12 and the air due to the large refractive index of the material of the light-emitting unit 12 can be improved, thereby improving the luminous efficiency of the light-emitting unit 12 and helping to improve the display brightness of the light-emitting diode display panel.

[0088] Optionally, the material of the first connection electrode 31 and the second connection electrode 32 includes any one of aluminum (Al), molybdenum (Mo), silver (Ag) and indium tin oxide (ITO).

[0089] ​Among them, by setting the first connection electrode 31 and the second connection electrode 32 to use aluminum (Al), molybdenum (Mo), silver (Ag) or indium tin oxide (ITO), the first connection electrode 31 and the second connection electrode 32 can be formed by a wet etching process, and the process equipment is simple, the etching rate is high, the reliability is good, and it is easy to implement. Those skilled in the art can set it according to actual needs. For example, the first connection electrode 31 and the second connection electrode 32 use aluminum (Al) with good ductility, thereby further reducing the possibility of disconnection of the first connection electrode 31 and the second connection electrode 32, and improving the reliability of the light-emitting diode display panel.

[0090] Further, the material of the first electrode 21 and the second electrode 22 includes gold (Au) or titanium (Ti).

[0091] Among them, by setting the material of the first electrode 21 and the second electrode 22 to be gold (Au) or titanium (Ti), the first electrode 21 and the second electrode 22 can be unaffected by the wet etching process during the preparation of the first connecting electrode 31 and the second connecting electrode 32, thereby further improving the reliability of the light-emitting diode display panel.

[0092] It should be noted that, based on any of the above embodiments, those skilled in the art may also set any other functional film layer in the light emitting diode display panel according to actual needs, and the embodiments of the present invention are not limited to this.

[0093] For example, Figure 2 and Figure 8 As shown, the light emitting unit 12 further includes an insulating passivation layer 46 , which is located at least between the first electrode 21 and the first active layer 122 and the second-type semiconductor layer 123 , and between the second electrode 22 and the first active layer 122 and the first-type semiconductor layer 121 .

[0094] By providing the insulating passivation layer 46 , short circuits between the film layers in the light-emitting unit 12 can be avoided, thereby ensuring that the light-emitting unit 12 can display normally.

[0095] Continue to refer Figure 2 and Figure 8 Optionally, the light emitting unit 12 further includes a lattice matching layer 124 , and the lattice matching layer 124 is located on a side of the second-type semiconductor layer 123 away from the substrate 10 .

[0096] Among them, when preparing the light-emitting unit 12 on the growth substrate 44, the lattice matching layer 124 can be formed by ion beam assisted deposition technology (Ion Beam Assisted Deposition, IBAD) technology, and the light-emitting unit 12 can be subsequently grown on the side of the lattice matching layer 124 away from the growth substrate 44 by epitaxial method. By setting the lattice matching layer 124, the lattice matching layer 124 is matched with the lattice of the epitaxial layer, which is helpful for the subsequent growth of the light-emitting unit 12.

[0097] Continue to refer Figure 2 and Figure 8 Optionally, the pixel driving circuit 11 includes a thin film transistor 50, and the thin film transistor 50 includes an active layer 51, a source electrode 52, a gate electrode 53 and a drain electrode 54. The pixel driving circuit 11 may also include a capacitor structure 60, and the capacitor structure 60 includes a first capacitor plate 61 and a second capacitor plate 62. The first capacitor plate 61 and / or the second capacitor plate 62 can be arranged in the same layer as the metal layer (source electrode 52, gate electrode 53 or drain electrode 54) in the thin film transistor 50, thereby reducing the setting of a metal layer, thereby achieving the purpose of reducing production costs and reducing substrate thickness. At the same time, the first capacitor plate 61 and / or the second capacitor plate 62 can be made of the same material as the metal layer in the thin film transistor 50, and the first capacitor plate 61 and / or the second capacitor plate 62 and the metal layer in the thin film transistor 50 can be prepared in the same process, thereby shortening the process time.

[0098] Continue to refer Figure 2 and Figure 8 Optionally, the light-emitting diode display panel also includes an insulating layer to isolate the various metal layers. For example, the insulating layer may include a stacked gate insulating layer 71, an interlayer dielectric layer 72, an insulating intermediate layer 73, a passivation layer 74 and a planarization layer 75. Those skilled in the art can set them according to actual needs.

[0099] Continue to refer Figure 2 and Figure 8 Optionally, a buffer layer 70 is further provided on one side of the substrate 10 close to the pixel driving circuit 11, and the buffer layer 70 can play a role in shockproofing, buffering and isolation.

[0100] Based on the same inventive concept, an embodiment of the present invention further provides a display device, Fig.10 A schematic diagram of a display device according to an embodiment of the present invention is shown in FIG. Fig.10 As shown, the display device 90 includes the display panel 91 described in any embodiment of the present invention. Therefore, the display device 90 provided in the embodiment of the present invention has the technical effect of the technical solution in any of the above embodiments, and the explanation of the same or corresponding structures and terms as the above embodiments will not be repeated here. The display device 90 provided in the embodiment of the present invention can be Fig.10 The mobile phone shown can also be any electronic product with a display function, including but not limited to the following categories: televisions, laptops, desktop displays, tablet computers, digital cameras, smart bracelets, smart glasses, car displays, medical equipment, industrial control equipment, touch interactive terminals, etc. The embodiments of the present invention do not specifically limit this.

[0101] Based on the same inventive concept, an embodiment of the present invention further provides a method for preparing a light emitting diode display panel, which is used to prepare any light emitting diode display panel provided in the above embodiments. The explanation of the structures and terms that are the same or corresponding to the above embodiments will not be repeated here. Fig.11 A schematic diagram of a process for preparing a light emitting diode display panel provided by an embodiment of the present invention is shown in FIG. Fig.11 As shown, the method comprises the following steps:

[0102] Step 110: Prepare a pixel driving circuit on one side of the substrate.

[0103] Fig.12 A schematic diagram of a process for preparing a pixel driving circuit provided by an embodiment of the present invention is shown in FIG. Fig.12 As shown, the pixel driving circuit 11 may include a thin film transistor 50, which includes an active layer 51, a source 52, a gate 53 and a drain 54. The pixel driving circuit 11 may also include a capacitor structure 60, which includes a first capacitor plate 61 and a second capacitor plate 62.

[0104] Continue to refer Fig.12 Optionally, an insulating layer may be prepared on the side of the substrate 10 close to the pixel driving circuit 11 to isolate the metal layers. For example, the insulating layer may include a stacked gate insulating layer 71, an interlayer dielectric layer 72, an insulating intermediate layer 73, a passivation layer 74 and a planarization layer 75. Those skilled in the art may set them according to actual needs.

[0105] Continue to refer Fig.12 Optionally, a buffer layer 70 may be prepared on the side of the substrate 10 close to the pixel driving circuit 11 to play a role in shockproofing, buffering and isolation.

[0106] Continue to refer Fig.12 Optionally, the light emitting diode display panel provided in the embodiment of the present invention further includes a sticky insulating layer 14 located on the side of the substrate 10 facing the light emitting unit 12 , and the sticky insulating layer 14 is in contact with the light emitting unit 12 .

[0107] Continue to refer Fig.12Optionally, a sticky insulating layer 14 may be prepared on the side of the pixel driving circuit 11 away from the substrate 10. When the light-emitting unit is subsequently transferred to the sticky insulating layer 14, the light-emitting unit can be fixed by the viscosity of the sticky insulating layer 14, thereby reducing the possibility of movement and misalignment of the light-emitting unit, thereby helping to improve the display effect of the light-emitting diode display panel.

[0108] Step 120, prepare a light-emitting unit on a growth substrate, wherein the light-emitting unit includes a first electrode, wherein the first electrode includes a first electrode portion and a second electrode portion connected to each other, wherein the first electrode portion is located on a side wall of the light-emitting unit, and the second electrode portion is located on a side of the light-emitting unit away from the growth substrate.

[0109] Fig.13 A schematic diagram of a process for preparing a light-emitting unit provided in an embodiment of the present invention is shown in FIG. Fig.13 As shown, the light-emitting unit 12 includes a first electrode 21 , which includes a first electrode portion 211 and a second electrode portion 212 connected to each other. The first electrode portion 211 is located on the side wall of the light-emitting unit 12 , and the second electrode portion 212 is located on a side of the light-emitting unit 21 away from the growth substrate 44 .

[0110] Continue to refer Fig.13 Optionally, the light emitting unit 12 further includes a first-type semiconductor layer 121, a first active layer 122 and a second-type semiconductor layer 123 which are stacked, the first active layer 122 is located between the first-type semiconductor layer 121 and the second-type semiconductor layer 123, and the second electrode portion 212 is connected to the first-type semiconductor layer 121.

[0111] Among them, Fig.13 As shown, in this embodiment, the second electrode portion 212 at the bottom of the first electrode 21 is connected to the first-type semiconductor layer 121, which helps to increase the contact area between the first electrode 21 and the first-type semiconductor layer 121, thereby reducing the transmission impedance of the driving signal.

[0112] Continue to refer Fig.13 Optionally, the light emitting unit 12 further includes a lattice matching layer 124 , and the lattice matching layer 124 is located on a side of the growth substrate 44 close to the second-type semiconductor layer 123 .

[0113] Among them, when preparing the light-emitting unit 12 on the growth substrate 44, the lattice matching layer 124 can be formed by ion beam assisted deposition technology (Ion Beam Assisted Deposition, IBAD) technology, and the light-emitting unit 12 can be subsequently grown on the side of the lattice matching layer 124 away from the growth substrate 44 by epitaxial method. By setting the lattice matching layer 124, the lattice matching layer 124 is matched with the lattice of the epitaxial layer, which is helpful for the subsequent growth of the light-emitting unit 12.

[0114] Continue to refer Fig.13 Optionally, a lattice matching layer 124 is provided on a side close to the growth substrate 44 and includes an uneven surface, which can improve the problem of total reflection of light generated by the light emitting unit 12 at the interface between the light emitting unit 12 and the air due to the large refractive index of the material of the light emitting unit 12, thereby improving the luminous efficiency of the light emitting unit 12 and helping to improve the display brightness of the light emitting diode display panel.

[0115] Herein, a patterning process may be performed on the growth substrate 44 to form an uneven shape, and then the light emitting unit 12 may be formed by epitaxial growth on the growth substrate 44 .

[0116] It should be noted that the embodiment of the present invention does not limit the specific material of the growth substrate 44. The growth substrate 44 may be made of sapphire or other materials suitable for epitaxial growth, and those skilled in the art may configure it according to actual needs.

[0117] Step 130: placing the light-emitting unit on a side of the pixel driving circuit away from the substrate, wherein the second electrode portion is located on a side of the light-emitting unit close to the substrate.

[0118] Fig.14 A schematic diagram of a process for placing a light-emitting unit provided in an embodiment of the present invention, such as Fig.14 As shown, the light emitting unit 12 is placed on a side of the pixel driving circuit 11 away from the substrate 10 , wherein the second electrode portion 212 is located on a side of the light emitting unit 12 close to the substrate 10 .

[0119] Continue to refer Fig.14 Optionally, the light emitting unit 12 is transferred to the adhesive insulating layer 14, so that the light emitting unit 12 is fixed by the adhesiveness of the adhesive insulating layer 14, reducing the possibility of movement and dislocation of the light emitting unit 12, thereby helping to improve the display effect of the light emitting diode display panel.

[0120] Step 140, prepare a first connecting electrode, wherein the first connecting electrode includes a first connecting portion and a second connecting portion connected to each other, wherein a plane where the first connecting portion is located intersects with a plane where the substrate is located, the first connecting portion is connected to the first electrode portion, and the second connecting portion is connected to the pixel driving circuit.

[0121] Continue to refer Figure 2By preparing a first connecting electrode 31, and setting the second connecting division 312 of the first connecting electrode 31 to be connected to the pixel driving circuit 11, the first connecting division 311 of the first connecting electrode 31 is overlapped with the first electrode division 211, so that the driving signal of the pixel driving circuit 11 is transmitted on the path of the second connecting division 312-first connecting division 311-first electrode division 211-second electrode division 212, thereby driving the light-emitting unit 12 to emit light.

[0122] Compared with the technical solution of bonding the light-emitting unit to the array substrate through a eutectic layer in the prior art, this embodiment realizes that the pixel driving circuit 11 drives the light-emitting unit 12 to emit light by setting the first connection section 311 of the first connection electrode 31 to contact and connect with the first electrode section 211 of the first electrode 21 along the side wall of the light-emitting unit 12 (at this time, the plane where the contact surface of the first connection section 311 and the first electrode section 211 intersects with the plane where the substrate 10 is located), so that the first connection electrode 31 can be prepared and connected through a conventional photolithography patterning process, without the need to perform the steps of heating-pressing-bonding the eutectic layer, thereby reducing the process difficulty; at the same time, in this embodiment, there is no need to set a more expensive eutectic layer, thereby reducing the cost of the light-emitting diode display panel.

[0123] Optionally, the light-emitting unit further includes a second electrode, the second electrode includes a third electrode portion and a fourth electrode portion connected to each other, the third electrode portion is located on a side wall of the light-emitting unit, and the fourth electrode portion is located on a side of the light-emitting unit away from the growth substrate.

[0124] Among them, continue to refer to Fig.13 The light-emitting unit 12 also includes a second electrode 22, which includes a third electrode portion 221 and a fourth electrode portion 222 connected to each other. The third electrode portion 221 is located on the side wall of the light-emitting unit 12, and the fourth electrode portion 222 is located on a side of the light-emitting unit 12 away from the growth substrate 40.

[0125] Optionally, the light emitting unit is placed before the pixel driving circuit on a side away from the substrate, further comprising:

[0126] A first metal layer is prepared on one side of the substrate, and the first metal layer is used to transmit a first power supply signal.

[0127] Among them, continue to refer to Fig.12 A first metal layer 13 is prepared on one side of the substrate 10. The first metal layer 13 is used to transmit a first power signal. The first power signal can be a PVEE signal, a GND signal or other signals. Those skilled in the art can set it according to actual needs, and the embodiment of the present invention is not limited to this.

[0128] Furthermore, after the light emitting unit is placed on a side of the pixel driving circuit away from the substrate, the method further comprises:

[0129] A second connecting electrode is prepared, the second connecting electrode comprising a third connecting section and a fourth connecting section connected to each other, the plane where the third connecting section is located intersects with the plane where the substrate is located, the third connecting section is connected to the third electrode section, and the fourth connecting section is connected to the first metal layer.

[0130] Continue to refer Figure 2 , by preparing a second connecting electrode 32, and setting the fourth connecting division 322 of the second connecting electrode 32 to be connected to the first metal layer 13, the third connecting division 321 of the second connecting electrode 32 is overlapped with the third electrode division 221, so that the first power supply signal transmitted on the first metal layer 13 is transmitted on the path of the fourth connecting division 322-the third connecting division 321-the third electrode division 221-the fourth electrode division 222, thereby driving the light-emitting unit 12 to emit light.

[0131] Compared with the technical solution of bonding the light-emitting unit to the array substrate through a eutectic layer in the prior art, this embodiment drives the light-emitting unit 12 to emit light by setting the third connection division 321 of the second connection electrode 32 to contact and connect with the third electrode division 221 of the second electrode 22 along the side wall of the light-emitting unit 12 (at this time, the plane where the contact surface of the third connection division 321 and the third electrode division 221 intersects with the plane where the substrate 10 is located), so that the second connection electrode 32 can be prepared and connected through a conventional photolithography patterning process, without the need to perform the steps of heating-pressing-bonding the eutectic layer, thereby reducing the process difficulty; at the same time, in this embodiment, there is no need to set a more expensive eutectic layer, thereby reducing the cost of the light-emitting diode display panel.

[0132] It should be noted that the first connection electrode 31 and the second connection electrode 32 can be manufactured in the same process, thereby shortening the process time.

[0133] Optionally, the preparing the first connecting electrode includes:

[0134] A first insulating layer is prepared, wherein the first insulating layer is located on a side of the substrate close to the light emitting unit, the first insulating layer comprises a first opening, and the light emitting unit is located in the first opening.

[0135] in, Fig.15 A schematic diagram of a process for preparing a first insulating layer provided by an embodiment of the present invention is as follows: Fig.15As shown, a first insulating layer 15 is prepared on a side of the substrate 10 close to the light emitting unit 12, and the first insulating layer 15 includes a first opening 151, and the light emitting unit 12 is located in the first opening 151. By preparing the first insulating layer 15 and locating the light emitting unit 12 in the first opening 151, the light emitting unit 12 can be further fixed. At the same time, the first insulating layer 15 can play an insulating role between adjacent light emitting units 12 to avoid short circuits between adjacent light emitting units 12, thereby improving the reliability of the light emitting diode display panel.

[0136] The first insulating layer is etched to expose a portion of the pixel driving circuit.

[0137] in, Fig.16 A schematic diagram of a process for etching a first insulating layer provided by an embodiment of the present invention, such as Fig.16 As shown, the first insulating layer 15 is etched to form a connection hole, thereby exposing the pixel driving circuit 11.

[0138] A connection electrode layer is formed on the first insulating layer and the side of the light emitting unit away from the substrate.

[0139] in, Fig.17 A schematic diagram of a process for preparing a connecting electrode layer provided in an embodiment of the present invention is as follows: Fig.17 As shown, a whole layer of connecting electrode layer 33 is prepared on the side of the first insulating layer 15 and the light emitting unit 12 away from the substrate 10 .

[0140] The connecting electrode layer is patterned to form the first connecting electrode.

[0141] in, Fig.18 A schematic diagram of a process for preparing a first connecting electrode provided by an embodiment of the present invention is shown in FIG. Fig.18 and Figure 2 As shown, photoresist coating, exposure and development are performed on the side of the connection electrode layer 33 away from the substrate 10 , and then the connection electrode layer 33 is etched and the photoresist is stripped to form the first connection electrode 31 .

[0142] Optionally, the preparing the second connecting electrode includes:

[0143] A first insulating layer is prepared, wherein the first insulating layer is located on a side of the substrate close to the light emitting unit, the first insulating layer comprises a first opening, and the light emitting unit is located in the first opening.

[0144] Among them, continue to refer to Figure 5A first insulating layer 15 is prepared on a side of the substrate 10 close to the light emitting unit 12. The first insulating layer 15 includes a first opening 151, and the light emitting unit 12 is located in the first opening 151. By preparing the first insulating layer 15 and locating the light emitting unit 12 in the first opening 151, the light emitting unit 12 can be further fixed. At the same time, the first insulating layer 15 can play an insulating role between adjacent light emitting units 12 to avoid short circuits between adjacent light emitting units 12, thereby improving the reliability of the light emitting diode display panel.

[0145] The first insulating layer is etched to expose a portion of the first metal layer.

[0146] Among them, continue to refer to Fig.16 , the first insulating layer 15 is etched to form a connection hole, thereby exposing the pixel driving circuit 11.

[0147] A connection electrode layer is formed on the first insulating layer and the side of the light emitting unit away from the substrate.

[0148] Among them, continue to refer to Fig.17 A whole connecting electrode layer 33 is prepared on the side of the first insulating layer 15 and the light emitting unit 12 away from the substrate 10 .

[0149] The connecting electrode layer is patterned to form the second connecting electrode.

[0150] Among them, continue to refer to Fig.18 and Figure 2 As shown, photoresist coating, exposure and development are performed on the side of the connection electrode layer 33 away from the substrate 10 , and then the connection electrode layer 33 is etched and the photoresist is stripped to form the second connection electrode 32 .

[0151] It should be noted that the first connection electrode 31 and the second connection electrode 32 can be manufactured in the same process, thereby shortening the process time.

[0152] Optionally, placing the light emitting unit on a side of the pixel driving circuit away from the substrate comprises:

[0153] The growth substrate prepared with the light-emitting unit is inverted on a side of the pixel driving circuit away from the substrate.

[0154] Among them, continue to refer to Fig. 9 For example, the growth substrate 44 on which the light-emitting units 12 are grown can be directly inverted on the adhesive insulating layer 14 to perform mass transfer of the light-emitting units 12 .

[0155] The light emitting unit is released to a side of the pixel driving circuit away from the substrate through a laser lift-off process.

[0156] Among them, continue to refer to Fig. 9 For example, the light-emitting unit 12 is released to the side of the pixel driving circuit 11 away from the substrate 10 through the laser lift-off process. This process does not require an additional transfer device to pick up and release the light-emitting unit 12, is not limited by the spacing between the pixels of the transfer device, has strong applicability, and improves the transfer efficiency of the light-emitting unit 12, which helps to achieve a large-scale transfer of large-area light-emitting units 12.

[0157] Optionally, when preparing the light-emitting unit 12 on the growth substrate 44, the surfaces of the second electrode portion 212 of the first electrode 21 and the fourth electrode portion 222 of the second electrode 22 away from the growth substrate 44 are polished so that the surfaces of the second electrode portion 212 and the fourth electrode portion 222 away from the growth substrate 44 are at the same height, which facilitates the subsequent transfer of the light-emitting unit 12.

[0158] It should be noted that releasing the light-emitting unit 12 to the side of the pixel driving circuit 11 away from the substrate 10 is not limited to the laser lift-off process. In other embodiments, those skilled in the art may also use a transfer device to perform mass transfer of the light-emitting unit 12, and the embodiments of the present invention are not limited to this.

[0159] Optionally, the material of the first connecting electrode 31 and the second connecting electrode 32 includes any one of aluminum (Al), molybdenum (Mo), silver (Ag) and indium tin oxide (ITO), so that the first connecting electrode 31 and the second connecting electrode 32 can be formed by a wet etching process, with simple process equipment, high etching rate, good reliability, and easy implementation.

[0160] Furthermore, the material of the first electrode 21 and the second electrode 22 includes gold (Au) or titanium (Ti), so that the first electrode 21 and the second electrode 22 are not affected by the wet etching process when preparing the first connecting electrode 31 and the second connecting electrode 32, thereby further improving the reliability of the light emitting diode display panel.

[0161] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A light emitting diode display panel, characterized in that: include: A substrate, and a pixel driving circuit and a light-emitting unit sequentially located on one side of the substrate; The light emitting unit comprises a first electrode; The first electrode comprises a first electrode sub-portion and a second electrode sub-portion connected to each other, the first electrode sub-portion is located on the side wall of the light-emitting unit, and the second electrode sub-portion is located on a side of the light-emitting unit close to the substrate; The light emitting diode display panel further comprises a first connecting electrode, the first connecting electrode comprises a first connecting sub-portion and a second connecting sub-portion connected to each other, the plane where the first connecting sub-portion is located intersects with the plane where the substrate is located; the first connecting sub-portion is connected to the first electrode sub-portion, the second connecting sub-portion is connected to the pixel driving circuit, and the plane where the first connecting sub-portion is located intersects with the plane where the second connecting sub-portion is located; The light emitting diode display panel further comprises a first metal layer located on a side of the substrate close to the light emitting unit, the first metal layer being used to transmit a first power signal; The light-emitting unit further includes a second electrode, the second electrode includes a third electrode portion and a fourth electrode portion connected to each other, the third electrode portion is located on a side wall of the light-emitting unit, and the fourth electrode portion is located on a side of the light-emitting unit close to the substrate; The light emitting diode display panel further comprises a second connecting electrode, the second connecting electrode comprises a third connecting sub-portion and a fourth connecting sub-portion connected to each other, the plane where the third connecting sub-portion is located intersects with the plane where the substrate is located; the third connecting sub-portion is connected to the third electrode sub-portion, and the fourth connecting sub-portion is connected to the first metal layer; A contact area between the third electrode section and the third connection section is greater than a contact area between the first electrode section and the first connection section.

2. The light emitting diode display panel according to claim 1, characterized in that: The light emitting unit further comprises a first-type semiconductor layer, a first active layer and a second-type semiconductor layer which are stacked, wherein the first active layer is located between the first-type semiconductor layer and the second-type semiconductor layer; The second electrode section is connected to the first-type semiconductor layer, and the fourth electrode section is connected to the second-type semiconductor layer.

3. The light emitting diode display panel according to claim 1, characterized in that: A contact surface between the third electrode section and the third connection section is located on at least two side walls of the light emitting unit, and a contact surface between the first electrode section and the first connection section is located on at least one side wall of the light emitting unit.

4. The light emitting diode display panel according to claim 1, characterized in that: The first electrode section and the third electrode section are respectively located on opposite side walls of the light emitting unit.

5. The light emitting diode display panel according to claim 1, characterized in that: The included angle between the first electrode portion and the second electrode portion is θ1, where θ1<90°.

6. The light emitting diode display panel according to claim 1, characterized in that: The light emitting diode display panel further comprises a sticky insulating layer located on a side of the substrate facing the light emitting unit, and the sticky insulating layer is in contact with the light emitting unit.

7. The light emitting diode display panel according to claim 6, characterized in that: The light-emitting unit is prepared on a growth substrate; the adhesion between the adhesive insulating layer and the light-emitting unit is greater than the adhesion between the light-emitting unit and the growth substrate.

8. The light emitting diode display panel according to claim 1, characterized in that: The light emitting diode display panel further includes a first insulating layer, the first insulating layer is located on a side of the substrate close to the light emitting unit, the first insulating layer includes a first opening, and the light emitting unit is located in the first opening.

9. The light emitting diode display panel according to claim 8, characterized in that: The height of the first insulating layer is H1, the height of the second electrode portion is H2, the height of the fourth electrode portion is H3, the height of the first electrode is H5, the height of the second electrode is H6, H4 is the larger one of H2 and H3, and H7 is the smaller one of H5 and H6, wherein H4<H1<H7.

10. The light emitting diode display panel according to claim 1, characterized in that: A side of the light emitting unit away from the substrate includes an uneven surface.

11. A display device, characterized in that: A light emitting diode display panel comprising any one of claims 1-10.

12. A method for preparing a light emitting diode display panel, characterized in that: The preparation method comprises: Prepare a pixel driving circuit on one side of the substrate; A light-emitting unit is prepared on a growth substrate, wherein the light-emitting unit includes a first electrode, wherein the first electrode includes a first electrode portion and a second electrode portion connected to each other, wherein the first electrode portion is located on a side wall of the light-emitting unit, and the second electrode portion is located on a side of the light-emitting unit away from the growth substrate; Placing the light-emitting unit on a side of the pixel driving circuit away from the substrate, wherein the second electrode portion is located on a side of the light-emitting unit close to the substrate; Prepare a first connection electrode, wherein the first connection electrode comprises a first connection sub-portion and a second connection sub-portion connected to each other, wherein a plane where the first connection sub-portion is located intersects with a plane where the substrate is located, the first connection sub-portion is connected to the first electrode sub-portion, the second connection sub-portion is connected to the pixel driving circuit, and a plane where the first connection sub-portion is located intersects with a plane where the second connection sub-portion is located; The light-emitting unit further includes a second electrode, the second electrode includes a third electrode portion and a fourth electrode portion connected to each other, the third electrode portion is located on a side wall of the light-emitting unit, and the fourth electrode portion is located on a side of the light-emitting unit away from the growth substrate; The light emitting unit is placed before the pixel driving circuit on a side away from the substrate, and further comprises: Prepare a first metal layer on one side of the substrate, wherein the first metal layer is used to transmit a first power supply signal; After the light emitting unit is placed on a side of the pixel driving circuit away from the substrate, the method further comprises: Prepare a second connection electrode, wherein the second connection electrode comprises a third connection sub-portion and a fourth connection sub-portion connected to each other, wherein a plane where the third connection sub-portion is located intersects with a plane where the substrate is located; the third connection sub-portion is connected to the third electrode sub-portion, and the fourth connection sub-portion is connected to the first metal layer; A contact area between the third electrode section and the third connection section is greater than a contact area between the first electrode section and the first connection section.

13. The method for preparing a light emitting diode display panel according to claim 12, characterized in that: The step of preparing the first connecting electrode comprises: Prepare a first insulating layer, wherein the first insulating layer is located on a side of the substrate close to the light-emitting unit, the first insulating layer comprises a first opening, and the light-emitting unit is located in the first opening; Etching the first insulating layer to expose a portion of the pixel driving circuit; forming a connection electrode layer on the first insulating layer and on a side of the light emitting unit away from the substrate; The connecting electrode layer is patterned to form the first connecting electrode.

14. The method for preparing a light emitting diode display panel according to claim 12, characterized in that: The method of preparing the second connecting electrode comprises: Prepare a first insulating layer, wherein the first insulating layer is located on a side of the substrate close to the light-emitting unit, the first insulating layer comprises a first opening, and the light-emitting unit is located in the first opening; Etching the first insulating layer to expose a portion of the first metal layer; forming a connection electrode layer on the first insulating layer and on a side of the light emitting unit away from the substrate; The connecting electrode layer is patterned to form the second connecting electrode.

15. The method for preparing a light emitting diode display panel according to claim 12, characterized in that: Placing the light emitting unit on a side of the pixel driving circuit away from the substrate comprises: Inverting the growth substrate prepared with the light-emitting unit on a side of the pixel driving circuit away from the substrate; The light emitting unit is released to a side of the pixel driving circuit away from the substrate through a laser lift-off process.

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