Display device

Abstract

The invention provides a display device. The display device comprises a driving substrate, a first light-emitting unit, a second light-emitting unit and a third light-emitting unit. The first light-emitting unit is bonded on one side of the driving substrate and comprises a first anode, a first light-emitting layer, a first cathode and a first contact hole connected with the first anode, and the second light-emitting unit is bonded on one side, away from the driving substrate, of the first light-emitting unit and comprises a second anode, a second light-emitting layer, a second cathode and a second contact hole connected with the second anode. The third light-emitting unit is bonded to the side, away from the driving substrate, of the second light-emitting unit and comprises a third anode, a third light-emitting layer, a third cathode and a third contact hole connected with the third anode. Wherein the first contact hole is connected with a common contact in the driving substrate, the second contact hole and the third contact hole are connected with the first contact hole, and the first anode or the first cathode is connected with the common contact in the driving substrate, so that common cathode or common anode is realized through the stacked contact holes, and the effective light-emitting area is increased.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display device. Background Art

[0002] With the maturity and development of wearable consumer electronic technologies such as AR and VR, the requirements for displays are getting higher and higher, especially in terms of the lifespan, resolution and brightness of display products. For example, the resolution (PPI) is required to be greater than 2000PPI, the brightness is required to be greater than 3000nits, and the longer the lifespan, the better. Traditional LCD or OLED displays cannot meet the display requirements of AR products. Micro semiconductor light emitting diodes (uLEDs) are considered to be the best display solution for AR products. Micro semiconductor light emitting diodes perform well in terms of brightness and lifespan.

[0003] At present, monochrome micro-semiconductor light-emitting diodes can realize the manufacturing and production of high-PPI displays, but there are still great technical difficulties in the manufacturing of full-color high-PPI display panels. The most mainstream method at present is to transfer R, G, and B monochrome micro-LEDs to the driving substrate separately through mass transfer to assemble and manufacture full-color displays. However, it is very challenging to integrate millions or even tens of millions of micro-LEDs with pixel driving circuit arrays. It becomes very difficult to ensure the stability and efficiency of the manufacturing process and the reliability of the transfer, and this method cannot achieve a micro-LED display with a higher PPI.

[0004] Application Contents

[0005] The purpose of the present application is to provide a display device, aiming to increase the effective light-emitting area by stacking contact holes.

[0006] The present application provides a display device, the display device comprising:

[0007] Driver substrate;

[0008] A first light-emitting unit, bonded to one side of the driving substrate, and comprising a first anode, a first light-emitting layer, a first cathode and a first contact hole, wherein the first contact hole penetrates the first anode, the first light-emitting unit and the first cathode;

[0009] a second light-emitting unit, bonded to a side of the first light-emitting unit away from the driving substrate, and comprising a second anode, a second light-emitting layer, a second cathode and a second contact hole, wherein the second contact hole penetrates the second anode, the second light-emitting unit and the second cathode;

[0010] a third light-emitting unit, bonded to a side of the second light-emitting unit away from the driving substrate, and comprising a third anode, a third light-emitting layer, a third cathode and a third contact hole, wherein the third contact hole penetrates the third anode, the third light-emitting unit and the third cathode;

[0011] Wherein, the first contact hole is connected to the common contact point in the driving substrate, the second contact hole is connected to the first contact hole, and the third contact hole is connected to the second contact hole;

[0012] The first anode is connected to the common contact in the driving substrate, the second anode is connected to the second contact hole, and the third anode is connected to the third contact hole;

[0013] Alternatively, the first cathode is connected to the common contact in the driving substrate, the second cathode is connected to the second contact hole, and the third cathode is connected to the third contact hole.

[0014] In some embodiments, the first contact hole includes a first conductive metal, and a first dielectric isolation layer between the first conductive metal and the first light emitting unit;

[0015] The second contact hole includes a second conductive metal and a second dielectric isolation layer located between the second conductive metal and the second light emitting unit;

[0016] The second contact hole includes a third conductive metal and a third dielectric isolation layer located between the third conductive metal and the third light emitting unit.

[0017] In some embodiments, the first contact hole is connected to the common contact point in the driving substrate, the second contact hole is connected to the first contact hole, and the third contact hole is connected to the second contact hole;

[0018] The first cathode is located at a side of the first anode away from the driving substrate, the second anode is located at a side of the second cathode away from the driving substrate, and the third anode is located at a side of the third cathode away from the driving substrate.

[0019] In some embodiments, the display device comprises:

[0020] a metal bonding layer, located between the driving substrate and the first anode, and connected to the first conductive metal;

[0021] a first transparent bonding layer, located between the first cathode and the second cathode;

[0022] a second transparent bonding layer, located between the second anode and the third cathode;

[0023] The first transparent bonding layer includes a first sub-bonding layer connected to the first cathode and a second sub-bonding layer connected to the second cathode, the first contact hole also penetrates the first sub-bonding layer, and the second contact hole also penetrates the second sub-bonding layer;

[0024] The second transparent bonding layer includes a third sub-bonding layer connected to the second anode and a fourth sub-bonding layer connected to the third cathode, and the third contact hole also penetrates the third sub-bonding layer and the fourth sub-bonding layer.

[0025] In some embodiments, the display device further comprises:

[0026] A first transparent guide layer, located between the first anode and the metal bonding layer;

[0027] A second transparent guide layer is located on a surface of the second anode facing away from the second cathode and extends between the second dielectric isolation layer and the second conductive metal;

[0028] The third transparent guide layer is located on the surface of the third anode away from the third cathode and extends between the third dielectric isolation layer and the third conductive metal.

[0029] In some embodiments, the display device has a stepped structure at an edge, and the stepped structure includes a first opening, a second opening, and a third opening respectively exposing the first cathode, the second cathode, and the third cathode; the display device further includes:

[0030] a first conductive layer connecting a first cathode exposed by the first opening and a first contact in the driving substrate;

[0031] a second conductive layer connecting a second cathode exposed by the second opening and a second contact in the driving substrate;

[0032] The third conductive layer connects the third cathode exposed by the third opening and the third contact in the driving substrate.

[0033] In some embodiments, the step structure includes a first dielectric protection layer, a second dielectric protection layer, and a third dielectric protection layer;

[0034] The first dielectric protection layer covers the edge of the step structure, and the first dielectric protection layer has the first opening and exposes the first contact; the first conductive layer covers the first dielectric protection layer and extends between the first contact and the first cathode below the first opening;

[0035] The second dielectric protection layer covers the first dielectric protection layer and the first conductive layer, and the second dielectric protection layer and the first dielectric protection layer have the second opening and expose the second contact; the second conductive layer covers the second dielectric protection layer and extends between the second contact and the second cathode below the second opening;

[0036] The third dielectric protection layer covers the second dielectric protection layer and the second conductive layer, and the third dielectric protection layer, the second dielectric protection layer and the first dielectric protection layer have the third opening and expose the third contact; the third conductive layer covers the third dielectric protection layer and extends between the third contact and the third cathode below the third opening.

[0037] In some embodiments, the top area of ​​the first contact hole away from the driving substrate is larger than the bottom area of ​​the first contact hole close to the driving substrate; the top area of ​​the second contact hole away from the driving substrate is larger than the bottom area of ​​the second contact hole close to the driving substrate; the top area of ​​the third contact hole away from the driving substrate is larger than the bottom area of ​​the third contact hole close to the driving substrate.

[0038] In some embodiments, the display device further comprises:

[0039] A first filter layer, located between the first light-emitting unit and the second light-emitting unit;

[0040] The second filter layer is located between the second light emitting unit and the third light emitting unit.

[0041] In some embodiments, the driving substrate includes a silicon substrate including a complementary metal oxide semiconductor.

[0042] In some embodiments, the first cathode is connected to the common contact of the driving substrate, the second cathode is connected to the second contact hole, and the third cathode is connected to the third contact hole;

[0043] The first anode is located at a side of the first cathode away from the drive substrate, the second cathode is located at a side of the second anode away from the drive substrate, and the third cathode is located at a side of the third anode away from the drive substrate.

[0044] In some embodiments, the display device comprises:

[0045] a metal bonding layer, located between the driving substrate and the first cathode and connected to the first conductive metal;

[0046] a first transparent bonding layer, located between the first anode and the second anode;

[0047] The second transparent bonding layer is located between the second cathode and the third anode.

[0048] In some embodiments, the display device further comprises:

[0049] a first transparent guide layer, located between the first anode and the first transparent bonding layer;

[0050] a second transparent guide layer, located between the second cathode and the second transparent bonding layer, and extending between the second dielectric isolation layer and the second conductive metal;

[0051] The third transparent guide layer is located on the surface of the third cathode away from the third anode and extends between the third dielectric isolation layer and the third conductive metal.

[0052] In some embodiments, the display device has a step structure at an edge, and the step structure includes a first opening, a second opening, and a third opening respectively exposing the first anode, the second anode, and the third anode; the display device further includes:

[0053] a first conductive layer connecting a first anode exposed by the first opening and a first contact in the driving substrate;

[0054] a second conductive layer connecting the first anode exposed by the second opening and a second contact in the driving substrate;

[0055] The third conductive layer connects the first anode exposed by the third opening and a third contact in the driving substrate.

[0056] In some embodiments, the step structure includes a first dielectric protection layer, a second dielectric protection layer, and a third dielectric protection layer;

[0057] The first dielectric protection layer covers the edge of the step structure, and the first dielectric protection layer has the first opening and exposes the first contact; the first conductive layer covers the first dielectric protection layer and extends between the first contact and the first anode below the first opening;

[0058] The second dielectric protection layer covers the first dielectric protection layer and the first conductive layer, and the second dielectric protection layer and the first dielectric protection layer have the second opening and expose the second contact; the second conductive layer covers the second dielectric protection layer and extends between the second contact and the second anode below the second opening;

[0059] The third dielectric protection layer covers the second dielectric protection layer and the second conductive layer, and the third dielectric protection layer, the second dielectric protection layer and the first dielectric protection layer have the third opening and expose the third contact; the third conductive layer covers the third dielectric protection layer and extends between the third contact and the third anode below the third opening.

[0060] The present application provides a display device, including a driving substrate, a first light-emitting unit, a second light-emitting unit and a third light-emitting unit. The first light-emitting unit is bonded to one side of the driving substrate and includes a first anode, a first light-emitting layer, a first cathode and a first contact hole, and the first contact hole penetrates the first anode, the first light-emitting unit and the first cathode. The second light-emitting unit is bonded to the side of the first light-emitting unit away from the driving substrate and includes a second anode, a second light-emitting layer, a second cathode and a second contact hole, and the second contact hole penetrates the second anode, the second light-emitting unit and the second cathode. The third light-emitting unit is bonded to the side of the second light-emitting unit away from the driving substrate and includes a third anode, a third light-emitting layer, a third cathode and a third contact hole, and the third contact hole penetrates the third anode, the third light-emitting unit and the third cathode. Wherein, the first contact hole is connected to the common contact in the driving substrate, the second contact hole is connected to the first contact hole, and the third contact hole is connected to the second contact hole. The first anode is connected to the common contact in the driving substrate, the second anode is connected to the second contact hole, and the third anode is connected to the third contact hole, or the first cathode is connected to the common contact in the driving substrate, the second cathode is connected to the second contact hole, and the third cathode is connected to the third contact hole. The present application can connect the second anode and the third anode (or the second cathode and the third cathode) to the common contact through the stacked first contact hole, the second contact hole and the third contact hole. Since the first anode (or the first cathode) is connected to the common contact, the driving substrate can drive the three anodes (or the three cathodes) together through the common contact. The stacked contact hole arrangement can save the area of ​​the contact holes, increase the effective light-emitting area, and thus increase the brightness. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0062] Figure 1 is a schematic diagram of the structure of a display device provided in some embodiments of the present application;

[0063] Figure 2 is a schematic diagram of the structure of a display device provided in some embodiments of the present application;

[0064] Figure 3a-3h is a schematic diagram of the structure of a display device provided in some embodiments of the present application during the preparation process;

[0065] Figure 4a-4h It is a schematic diagram of the structure of the display device provided in some embodiments of the present application during the preparation process. DETAILED DESCRIPTION

[0066] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0067] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0068] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0069] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0070] See also Figure 1 , Figure 11 is a schematic diagram of the structure of the display device provided in some embodiments of the present application. The display device 100 can be applied to various electronic devices, such as wearable devices such as smart bracelets, smart watches, virtual reality (VR) devices, mobile phones, e-books and e-newspapers, televisions, portable computers, foldable and rollable flexible display and lighting devices. The display device 100 can be specifically applied to micro-light-emitting diode displays (Micro-LED).

[0071] The display device 100 includes a drive substrate 10, a first light emitting unit L1, a second light emitting unit L2, and a third light emitting unit L3. The first light emitting unit L1 is bonded to one side of the drive substrate 10 and includes a first anode P1, a first cathode N1, and a first contact hole C1. The second light emitting unit L2 is bonded to the side of the first light emitting unit L1 away from the drive substrate 10 and includes a second anode P2, a second cathode N2, and a second contact hole C2. The third light emitting unit L3 is bonded to the side of the second light emitting unit L2 away from the drive substrate 10 and includes a third anode P3, a third cathode N3, and a third contact hole C3. The first contact hole C1 is connected to the common contact 124 in the drive substrate 10, the second contact hole C2 is connected to the first contact hole C1, and the third contact hole C3 is connected to the second contact hole C2. The first anode P1 is connected to the common contact 124 of the driving substrate 10, the second anode P2 is connected to the second contact hole C2, and the third anode P3 is connected to the third contact hole C3; or the first cathode N1 is connected to the common contact 124 of the driving substrate 10, the second cathode N2 is connected to the second contact hole C2, and the third cathode N3 is connected to the third contact hole C3.

[0072] In some embodiments, the driving substrate 10 includes a complementary metal oxide semiconductor (CMOS). Specifically, the CMOS may include a driving circuit layer 11 and an insulating layer 12, wherein the insulating layer 12 is located between the driving circuit layer 11 and the first light-emitting unit L1. The driving circuit layer 11 is formed in a silicon substrate, and the insulating layer 12 may be an insulating material such as silicon oxide. Due to the high integration and small size of CMOS, circuit driving can be provided for a high-resolution display device 100.

[0073] The driving substrate 10 may further include a first contact 121 , a second contact 122 , a third contact 123 and a common contact 124 located in the insulating layer 12 , and these contacts are used to achieve connection between the light emitting unit and the driving circuit layer 11 .

[0074] The first light-emitting unit L1, the second light-emitting unit L2 and the third light-emitting unit L3 can be any one of a red LED, a green LED and a blue LED, and they are different from each other. For example, the first light-emitting unit L1, the second light-emitting unit L2 and the third light-emitting unit L3 are red LED, green LED and blue LED respectively. Therefore, the present application can integrate the red LED, green LED and blue LED onto the driving substrate 10 by bonding and stacking, and can realize a micro color LED display with a resolution greater than 5000 without the method of mass transfer, and the pixel density can be increased by more than 50%.

[0075] The first light-emitting unit L1, the second light-emitting unit L2 and the third light-emitting unit L3 further include a first light-emitting layer E1, a second light-emitting layer E2 and a third light-emitting layer E3, respectively. The first light-emitting layer E1 includes a P-type semiconductor layer and an N-type semiconductor layer, the second light-emitting layer E2 includes a P-type semiconductor layer and an N-type semiconductor layer, and the third light-emitting layer E3 includes a P-type semiconductor layer and an N-type semiconductor layer. The P-type semiconductor layers are all connected to the anode, and the N-type semiconductor layers are all connected to the cathode.

[0076] In some embodiments, the first anode P1 is connected to the common contact 124 of the drive substrate 10, the second anode P2 is connected to the second contact hole C2, and the third anode P3 is connected to the third contact hole C3. The first cathode N1 is located on the side of the first anode P1 away from the drive substrate 10, the second anode P2 is located on the side of the second cathode N2 away from the drive substrate 10, and the third anode P3 is located on the side of the third cathode N3 away from the drive substrate 10. Therefore, compared with the electrodes in the first light-emitting unit L1, the directions of the electrodes in the second light-emitting unit L2 and the third light-emitting unit L3 are inverted.

[0077] The display device 100 may further include a first transparent guiding layer D1, a second transparent guiding layer D2, and a third transparent guiding layer D3. The first transparent guiding layer D1 is located on the surface of the first anode P1 away from the first cathode N1, the second transparent guiding layer D2 is located on the surface of the second anode P2 away from the second cathode N2, and the third transparent guiding layer D3 is located on the surface of the third anode P3 away from the third cathode N3. The first transparent guiding layer D1, the second transparent guiding layer D2, and the third transparent guiding layer D3 are in contact with the anode, which can promote the current of the anode to move in the lateral direction (perpendicular to the bonding direction) and reduce power consumption. The bonding direction is Z. The second transparent guiding layer D2 and the third transparent guiding layer D3 may not affect the light emission of the second light-emitting unit L2 and the third light-emitting unit L3.

[0078] The display device 100 may further include a metal bonding layer B0, a first transparent bonding layer B1, and a second transparent bonding layer B2. The materials of the first transparent bonding layer B1 and the second transparent bonding layer B2 may be silicon dioxide. The metal bonding layer B0 is located between the drive substrate 10 and the first transparent guide layer D1, the first transparent bonding layer B1 is located between the first cathode N1 and the second cathode N2, and the second transparent bonding layer B2 is located between the second anode P2 and the third cathode N3.

[0079] The metal bonding layer B0 is connected to the driving circuit layer 11 through a common contact 124. The first transparent bonding layer B1 includes a first sub-bonding layer connected to the first cathode N1, and a second sub-bonding layer (not labeled) connected to the second cathode N2. The second transparent bonding layer B2 includes a third sub-bonding layer connected to the second anode P2, and a fourth sub-bonding layer (not labeled) connected to the third cathode N3.

[0080] The display device 100 may further include a first filter layer DBR1 and a second filter layer DBR2, wherein the first filter layer DBR1 is located between the first light emitting unit L1 and the second light emitting unit L2, and the second filter layer DBR2 is located between the second light emitting unit L2 and the third light emitting unit L3. Specifically, the first filter layer DBR1 is located between the second sub-bonding layer and the second cathode N2, and the second filter layer DBR2 is located between the fourth sub-bonding layer and the third cathode N3. The first filter layer DBR1 can block the light emitted by the second light emitting unit L2 from being emitted toward the first light emitting unit L1, but does not affect the light emitted by the first light emitting unit L1 from being transmitted upward. The second filter layer DBR2 can block the light emitted by the third light emitting unit L3 from being emitted toward the second light emitting unit L2, but does not affect the light emitted by the second light emitting unit L2 from being transmitted upward.

[0081] The first contact hole C1 penetrates the first light-emitting unit L1, and is connected to the metal bonding layer B0 at one end close to the drive substrate 10. The second contact hole C2 penetrates the second light-emitting unit L2, and the second guide layer extends into the second contact hole C2. The third contact hole C3 penetrates the third light-emitting unit L3, and the third transparent guide layer D3 extends into the third contact hole C3.

[0082] In some embodiments, the first contact hole C1 includes a first conductive metal M1 and a first dielectric isolation layer S1 located between the first conductive metal M1 and the first light-emitting unit L1. The second contact hole C2 includes a second conductive metal M2, a portion of a second transparent guide layer D2, and a second dielectric isolation layer S2, wherein the portion of the second transparent guide layer D2 is located between the second conductive metal M2 and the second light-emitting unit L2, and the second dielectric isolation layer S2 is located between the portion of the second transparent guide layer D2 and the second light-emitting unit L2. The third contact hole C3 includes a third conductive metal M3, a portion of a third transparent guide layer D3, and a third dielectric isolation layer S3, wherein the portion of the third transparent guide layer D3 is located between the third conductive metal M3 and the third light-emitting unit L3, and the third dielectric isolation layer S3 is located between the third transparent guide layer D3 and the third light-emitting unit L3.

[0083] In some embodiments, the top area of ​​the first contact hole C1 away from the driving substrate 10 is larger than the bottom area of ​​the first contact hole C1 close to the driving substrate 10. The top area of ​​the second contact hole C2 away from the driving substrate 10 is larger than the bottom area of ​​the second contact hole C2 close to the driving substrate 10. The top area of ​​the third contact hole C3 away from the driving substrate 10 is larger than the bottom area of ​​the third contact hole C3 close to the driving substrate 10.

[0084] Specifically, the first contact hole C1 sequentially penetrates the first sub-bonding layer, the first cathode N1, the first light-emitting layer E1, the first anode P1, and the first transparent guide layer D1 along the bonding direction (Z), and the bottom is connected to the metal bonding layer B0. The second contact hole C2 sequentially penetrates the second anode P2, the second light-emitting layer E2, the second cathode N2, the first filter layer DBR1, and the second sub-bonding layer along the bonding direction (Z), and the bottom is connected to the first contact hole C1. The third contact hole C3 sequentially penetrates the second anode P2, the second light-emitting layer E2, the second cathode N2, the second filter layer DBR2, and the second transparent bonding layer B2 along the bonding direction (Z), and the bottom is connected to the second contact hole C2.

[0085] In order to connect the second anode P2 to the second contact hole C2 through the second transparent guide layer D2, the second anode P2 is disposed on the side of the second cathode N2 away from the drive substrate 10. If the second cathode N2 is disposed on the side of the second anode P2 away from the drive substrate 10, the second contact hole C2 cannot be formed after bonding the second light-emitting unit L2. The positional relationship between the third anode P3 and the third cathode N3 is similar.

[0086] Therefore, the present application can form the first contact hole C1 after bonding the first light-emitting unit L1 and forming the first sub-bonding layer, and then form the second contact hole C2 after bonding the second light-emitting unit L2, and finally form the third contact hole C3 after bonding the third light-emitting unit L3. There is no need to align the contact holes in the bonding process, which simplifies the bonding difficulty and improves the quality and yield of the bonding process.

[0087] In some embodiments, the display device 100 has a step structure at the edge, and the step structure includes a first opening K1, a second opening K2, and a third opening K3 that respectively expose the first cathode N1, the second cathode N2, and the third cathode N3. The display device 100 also includes a first conductive layer 101, a second conductive layer 102, and a third conductive layer 103. The first conductive layer 101 connects the first cathode N1 exposed by the first opening K1 and the first contact 121 in the drive substrate 10, the second conductive layer 102 connects the second cathode N2 exposed by the second opening K2 and the second contact 122 in the drive substrate 10, and the third conductive layer 103 connects the third cathode N3 exposed by the third opening K3 and the third contact 123 in the drive substrate 10.

[0088] Specifically, the step structure includes a first dielectric protection layer, a second dielectric protection layer and a third dielectric protection layer (not shown). The first dielectric protection layer covers the edge of the step structure, and the first dielectric protection layer has the first opening K1 and exposes the first contact 121. The first conductive layer 101 covers the first dielectric protection layer and connects the first contact 121 and the first cathode N1 below the first opening K1.

[0089] The second dielectric protection layer covers the first dielectric protection layer and the first conductive layer 101. The second dielectric protection layer and the first dielectric protection layer have the second opening K2 and expose the second contact 122. The second conductive layer 102 covers the second dielectric protection layer and connects the second contact 122 to the second cathode N2 below the second opening K2.

[0090] The third dielectric protection layer covers the second dielectric protection layer and the second conductive layer 102. The third dielectric protection layer, the second dielectric protection layer and the first dielectric protection layer have the third opening K3 and expose the third contact 123. The third conductive layer 103 covers the third dielectric protection layer and connects the third contact 123 and the third cathode N3 under the third opening K3.

[0091] Therefore, in the display device 100 provided in the embodiment of the present application, the first anode P1 is connected to the common contact 124 of the driving substrate 10, and the second anode P2 and the third anode P3 are connected to the common contact 124 of the driving substrate 10 through the first contact hole C1, the second contact hole C2 and the third contact hole C3 connected in alignment, so the first anode P1, the second anode P2 and the third anode P3 are connected to the common contact 124 as a common anode contact. The first cathode N1, the second cathode N2 and the third cathode N3 are connected to the driving circuit layer 11 through the first contact 121, the second contact 122 and the third contact 123 respectively to drive the light emission separately. Since the first contact hole C1, the second contact hole C2 and the third contact hole C3 are stacked in the bonding direction (Z), compared with the solution in which the first anode P1, the second anode P2 and the third anode P3 are led out separately through the contact hole, the area of ​​the contact hole can be saved, the effective light emitting area can be increased, and the brightness can be increased. Moreover, the first anode P1, the second anode P2 and the third anode P3 are controlled together to reduce power consumption.

[0092] See also Figure 2 , Figure 2 1 is a schematic diagram of the structure of the display device provided by some embodiments of the present application. For ease of understanding and brief description, the same reference numerals are used for the same structures as those in the above embodiments, and the same structures are not described in detail. Only the different structures are described in detail in this embodiment.

[0093] The display device 200 of this embodiment and Figure 1 The difference between the display device 100 in the embodiment is that the first cathode N1 is connected to the common contact 124 of the drive substrate 10, the second cathode N2 is connected to the second contact hole C2, the third cathode N3 is connected to the third contact hole C3, and the first anode P1, the second anode P2 and the third anode P3 are connected to the drive substrate 10 separately through the first conductive layer 101, the second conductive layer 102 and the third conductive layer 103. The first anode P1 is located on the side of the first cathode N1 away from the drive substrate 10, the second cathode N2 is located on the side of the second anode P2 away from the drive substrate 10, and the third cathode N3 is located on the side of the third anode P3 away from the drive substrate 10. In other words, the positions of the anode and cathode in each light-emitting unit in the display device 200 are opposite to those in the display device 100. In this way, the contact holes can be formed after bonding, and bonding alignment is not required, which simplifies the bonding difficulty and improves the quality and yield of the bonding process.

[0094] In some embodiments, the display device 200 has a stepped structure at an edge, and the stepped structure includes a first opening K1 , a second opening K2 , and a third opening K3 that expose the first anode P1 , the second anode P2 , and the third anode P3 , respectively.

[0095] The display device 200 further includes a first conductive layer 101, a second conductive layer 102, and a third conductive layer 103. The first conductive layer 101 connects the first anode P1 exposed by the first opening K1 and the first contact 121 in the drive substrate 10, the second conductive layer 102 connects the first anode P1 exposed by the second opening K2 and the second contact 122 in the drive substrate 10, and the third conductive layer 103 connects the first anode P1 exposed by the third opening K3 and the third contact 123 in the drive substrate 10.

[0096] Specifically, the step structure includes a first dielectric protection layer, a second dielectric protection layer and a third dielectric protection layer (not shown). The first dielectric protection layer covers the edge of the step structure, and the first dielectric protection layer has the first opening K1 and exposes the first contact 121. The first conductive layer 101 covers the first dielectric protection layer and connects the first contact 121 and the first anode P1 below the first opening K1.

[0097] The second dielectric protection layer covers the first dielectric protection layer and the first conductive layer 101. The second dielectric protection layer and the first dielectric protection layer have the second opening K2 and expose the second contact 122. The second conductive layer 102 covers the second dielectric protection layer and connects the second contact 122 to the second anode P2 below the second opening K2.

[0098] The third dielectric protection layer covers the second dielectric protection layer and the second conductive layer 102. The third dielectric protection layer, the second dielectric protection layer and the first dielectric protection layer have the third opening K3 and expose the third contact 123. The third conductive layer 103 covers the third dielectric protection layer and connects the third contact 123 and the third anode P3 under the third opening K3.

[0099] It should be noted that the first transparent guide layer D1 is connected to the first anode P1 to promote current transmission in the horizontal line, while the second transparent guide layer D2 and the third transparent guide layer D3 are connected to the second cathode N2 and the third cathode N3 respectively, and their function is to connect the cathode to the contact hole, thereby realizing a common cathode.

[0100] In some embodiments, a transparent guide layer may also be disposed on the surfaces of the second anode P2 and the third anode P3.

[0101] The display device 200 may further include a metal bonding layer B0, a first transparent bonding layer B1, and a second transparent bonding layer B2. The materials of the first transparent bonding layer B1 and the second transparent bonding layer B2 may be silicon dioxide. The metal bonding layer B0 is located between the drive substrate 10 and the first cathode N1, and is connected to the first conductive metal M1. The first transparent bonding layer B1 is located between the first anode P1 and the second anode P2, and the second transparent bonding layer B2 is located between the second cathode N2 and the third anode P3.

[0102] The display device 200 may further include a first transparent guide layer D1, a second transparent guide layer D2, and a third transparent guide layer D3. The first transparent guide layer D1 is located between the first anode P1 and the first transparent bonding layer B1, and the second transparent guide layer D2 is located between the second cathode N2 and the second transparent bonding layer B2, and extends between the second dielectric isolation layer S2 and the second conductive metal M2. The third transparent guide layer D3 is located on the surface of the third cathode N3 away from the third anode P3, and extends between the third dielectric isolation layer S3 and the third conductive metal M3.

[0103] In the display device 200 provided in the embodiment of the present application, the first cathode N1 is connected to the common contact 124 of the driving substrate 10, the second cathode N2 is connected to the second contact hole C2, and the third cathode N3 is connected to the third contact hole C3. The first contact hole C1, the second contact hole C2, and the third contact hole C3 are stacked to connect the second cathode N2 and the third cathode N3 to the common contact 124. Since the first cathode N1 is connected to the common contact 124, the driving substrate 10 can drive the three cathodes together through the common contact 124. The stacked contact hole arrangement can save the area of ​​the contact holes, increase the effective light-emitting area, and thus increase the brightness.

[0104] See also Figure 3a-3h , Figure 3a-3h 1 is a schematic diagram of the structure of the display device provided in some embodiments of the present application during the preparation process. This embodiment takes the preparation of the above-mentioned display device 100 as an example to illustrate the preparation method of the display device 100, so please refer to the following. Figure 1 , wherein the first light emitting unit L1 is a red LED, the second light emitting unit L2 is a green LED, the third light emitting unit L3 is a blue LED, the anode is a P electrode, and the cathode is an N electrode.

[0105] In the first step, a metal bonding layer B0 is deposited on the surface of the driving substrate 10, and a first transparent guide layer D1 and a metal bonding layer B0 are deposited on the surface of the red LED epitaxial layer. The red LED epitaxial layer and the driving substrate 10 are bonded together by full-surface metal bonding. The red LED epitaxial substrate backplane is peeled off and removed to expose the N-electrode surface, and the first sub-bonding layer B11 is deposited on the red LED surface without the epitaxial backplane. A first contact hole C1 is formed on the surface of the red LED by etching and patterning, and a first dielectric isolation layer S1 is deposited on the side wall of the first contact hole C1. The first dielectric isolation layer S1 at the bottom of the first contact hole C1 is etched and removed, and the first conductive metal M1 is filled in the first contact hole C1. Finally, the first conductive metal M1 in the non-first contact hole C1 is ground and removed by the CMP process. The structure is as shown in FIG. Figure 3a shown.

[0106] It should be noted that during the preparation process, the first contact hole C1 is in a hole shape, and after the first contact hole C1 is filled, the first contact hole C1 is a solid structure, so in the finally formed display device, the first contact hole C1 is a solid structure.

[0107] In the second step, the first filter layer DBR1 and the second sub-bonding layer are deposited on the N electrode surface of the green LED epitaxial (the green LED epitaxial P electrode is at the bottom and the N electrode is at the top), and the green LED epitaxial and the red LED epitaxial are bonded together through the first sub-bonding layer B11 and the second sub-bonding layer (forming the first transparent bonding layer B1). After bonding, the green LED epitaxial backplane is peeled off and removed to expose the P electrode surface. The second contact hole C2 is etched on the surface of the bonded green LED epitaxial, and the position of the second contact hole C2 is aligned with the first contact hole C1. After etching, the first conductive metal M1 in the first contact hole C1 is exposed. After the second contact hole C2 is etched, the second dielectric isolation layer S2 is deposited on the side wall of the second contact hole C2, and the second dielectric isolation layer S2 at the bottom of the second contact hole C2 and the P electrode surface of the green LED epitaxial is etched and removed, exposing the P electrode and the first conductive metal M1 in the bottom first contact hole C1. The second transparent guide layer D2 is deposited on the P electrode surface of the green LED epitaxy and in the second contact hole C2, and the second conductive metal M2 is deposited in the second contact hole C2, and the second conductive metal M2 fills the second contact hole C2. The second conductive metal M2 in the non-second contact hole C2 is ground and removed by the CMP process to expose the bottom second transparent guide layer D2, and finally the third sub-bonding layer B21 is deposited on the surface of the second transparent guide layer D2 of the green LED epitaxy. The structure is as follows Figure 3b shown.

[0108] The third step is to deposit the second filter layer DBR2 and the fourth sub-bonding layer on the N electrode surface of the blue LED epitaxial (the blue LED epitaxial P electrode is at the bottom and the N electrode is at the top), and bond the blue LED epitaxial and the green LED epitaxial together through the third sub-bonding layer B21 and the fourth sub-bonding layer (forming the second transparent bonding layer B2). After bonding, the blue LED epitaxial backplane is peeled off and removed to expose the P electrode surface, and the third contact hole C3 is etched on the bonded blue LED epitaxial surface. The position of the third contact hole C3 is aligned with the second contact hole C2, and the second conductive metal M2 in the second contact hole C2 is exposed after etching. After the third contact hole C3 is etched, the third dielectric isolation layer S3 is deposited on the side wall of the third contact hole C3, and the third dielectric isolation layer S3 at the bottom of the third contact hole C3 and the P electrode surface of the blue LED epitaxial is etched and removed, exposing the P electrode and the second conductive metal M2 in the bottom second contact hole C2. The third transparent guide layer D3 is deposited on the P electrode surface of the blue LED epitaxial and in the third contact hole C3, and the third conductive metal M3 is deposited in the third contact hole C3. The third conductive metal M3 fills the third contact hole C3. The third conductive metal M3 in the non-third contact hole C3 is ground and removed by CMP process to expose the bottom third transparent guide layer D3. The structure is as follows: Figure 3c shown.

[0109] The fourth step is to pattern the vertically bonded multi-layer LED epitaxy into a single LED light-emitting unit through a patterned etching process. Specifically, the etching is performed from top to bottom. The blue LED (third light-emitting unit L3) is etched to the N-electrode position of the blue LED, the green LED (second light-emitting unit L2) is etched to the N-electrode position of the green LED, and the red LED (first light-emitting unit L1) is etched to the N-electrode position of the red LED. Finally, the area between adjacent stacked light-emitting units is etched to a position below the underlying metal bonding layer B0, exposing the N-electrode contact holes of the three RGB light-emitting units on the underlying drive substrate 10 (the first contact 121, the second contact 122, and the third contact 123, respectively). The structure is as follows: Figure 3d shown.

[0110] In the fifth step, a dielectric protection layer S is deposited on the side wall of the light-emitting unit after etching and patterning. The dielectric protection layer S is removed at the N electrode (first cathode N1) of the red LED and the N electrode contact hole (first contact 121) by etching and patterning to form a conductive N electrode contact hole and a first opening K1, that is, the first contact 121 is exposed and the first opening K1 is formed. The structure is as follows: Figure 3e shown.

[0111] Step 6: deposit the first conductive layer 101 on the side wall surface of the red LED where the N electrode and the N electrode contact hole are leaking out, and remove the first conductive layer 101 other than the connection between the N electrode and the N electrode contact hole of the red LED by etching and patterning, so as to realize the independent conduction between the N electrode and the N electrode contact hole of the red LED. The structure is as follows: Figure 3f shown.

[0112] Step 7: Deposit a dielectric protection layer S on the side wall of the light-emitting unit after etching and patterning, and remove the dielectric protection layer S at the N electrode (second cathode N2) and the N electrode contact hole (second contact 122) of the green LED by etching and patterning, forming a conductive N electrode contact hole and a second opening K2. Deposit a second conductive layer 102 on the side wall surface of the green LED where the N electrode and the N electrode contact hole are leaking, and remove the second conductive layer 102 other than the connection between the N electrode and the N electrode contact hole of the green LED by etching and patterning, so that the N electrode and the N electrode contact hole of the green LED are separately conductive, and the structure is as follows: Figure 3g shown.

[0113] In the eighth step, a dielectric protection layer S is deposited on the side wall of the light-emitting unit after etching and patterning, and the dielectric protection layer S is removed at the N electrode (third cathode N3) of the blue LED and the N electrode contact hole (third contact 123) by etching and patterning to form a conductive N electrode contact hole and a third opening K3. A third conductive layer 103 is deposited on the side wall surface of the blue LED where the N electrode and the N electrode contact hole are leaking out, and the third conductive layer 103 other than the connection between the N electrode of the blue LED and the N electrode contact hole is removed by etching and patterning to achieve independent conduction between the N electrode of the blue LED and the N electrode contact hole. The structure is as follows: Figure 3h shown.

[0114] In the ninth step, a transparent dielectric protection layer S is deposited on the surface of the LED micro display device to protect the LED micro display device as a whole and improve the reliability of the micro display device. The dielectric protection layer S in the PAD area that does not need to be protected is etched away. The structure is as follows: Figure 1 shown.

[0115] The preparation method of the display device 100 provided in the embodiment of the present application grows the P / N electrodes of the green LED epitaxy and the blue LED epitaxy in an inverted manner (first grow the P electrode, then grow the light-emitting layer, and finally grow the N electrode). After the bonding is completed, the contact holes are etched to fill the metal to form a common anode structure, which reduces the alignment bonding, simplifies the difficulty of the bonding process, and improves the quality and yield of the bonding process.

[0116] See also Figure 4a-4h , Figure 4a-4h2 is a schematic diagram of the structure of the display device provided in some embodiments of the present application during the preparation process. This embodiment takes the preparation of the above-mentioned display device 200 as an example to illustrate the preparation method of the display device 200, so please refer to the following. Figure 2 , wherein the first light emitting unit L1 is a red LED, the second light emitting unit L2 is a green LED, the third light emitting unit L3 is a blue LED, the anode is a P electrode, and the cathode is an N electrode.

[0117] In the first step, a metal bonding layer B0 is deposited on the surface of the driving substrate 10, and a first transparent guide layer D1 and a metal bonding layer B0 are deposited on the surface of the red LED epitaxial layer. The red LED epitaxial layer and the driving substrate 10 are bonded together by full-surface metal bonding. The red LED epitaxial substrate backplane is peeled off and removed to expose the P electrode surface, and the first sub-bonding layer B11 is deposited on the red LED epitaxial surface with the epitaxial backplane removed. A first contact hole C1 is formed on the red LED epitaxial surface by etching and patterning, and a first dielectric isolation layer S1 is deposited on the side wall of the first contact hole C1. The first dielectric isolation layer S1 at the bottom of the first contact hole C1 is etched and removed, and the first conductive metal M1 is filled in the first contact hole C1. Finally, the first conductive metal M1 in non-first contact hole C1 is ground and removed by a CMP process, and the structure is as shown. Figure 4a shown.

[0118] In the second step, a second transparent guide layer D2, a first filter layer DBR1 and a second sub-bonding layer are deposited on the surface of the green LED epitaxial P electrode, and the green LED epitaxial and the red LED epitaxial are bonded together through the first sub-bonding layer B11 and the second sub-bonding layer. After bonding, the green LED epitaxial backplane is peeled off and removed to expose the N electrode surface. A second contact hole C2 is etched on the surface of the bonded green LED epitaxial. The position of the second contact hole C2 is aligned with the first contact hole C1 in the bottom red LED epitaxial. After etching, the first conductive metal M1 in the first contact hole C1 of the bottom red LED epitaxial is exposed. After the second contact hole C2 is etched, a second dielectric isolation layer S2 is deposited on the side wall of the second contact hole C2. The second dielectric isolation layer S2 at the bottom of the second contact hole C2 and the N electrode surface of the green LED epitaxial are etched and removed to expose the N electrode and the first conductive metal M1 in the bottom first contact hole C1. A transparent conductive layer D20 is deposited on the N electrode surface of the green LED epitaxy and in the second contact hole C2, and a second conductive metal M2 is deposited in the second contact hole C2, and the second conductive metal M2 fills the second contact hole C2. The second conductive metal M2 in the non-second contact hole C2 is ground and removed by a CMP process to expose the bottom transparent conductive layer D20, and finally a third sub-bonding layer B21 is deposited on the surface of the transparent conductive layer D20 of the green LED epitaxy. The structure is as follows: Figure 4b shown.

[0119] In the third step, a third transparent guide layer D3, a second filter layer DBR2 and a fourth sub-bonding layer are deposited on the surface of the blue LED epitaxial P electrode, and the blue LED epitaxial and the green LED epitaxial are bonded together through the third sub-bonding layer B21 and the fourth sub-bonding layer. After bonding, the blue LED epitaxial backplane is peeled off and removed to expose the N electrode surface, and a third contact hole C3 is etched on the bonded blue LED epitaxial surface. The position of the third contact hole C3 is aligned with the second contact hole C2 on the bottom green LED epitaxial, and the second conductive metal M2 in the second contact hole C2 of the bottom green LED epitaxial is exposed after etching. After the etching of the third contact hole C3 is completed, a third dielectric isolation layer S3 is deposited on the side wall of the third contact hole C3, and the third dielectric isolation layer S3 at the bottom of the third contact hole C3 and the N electrode surface of the blue LED epitaxial is etched and removed, exposing the N electrode and the second conductive metal M2 in the second contact hole C2 of the bottom. A transparent conductive layer D30 is deposited on the N electrode surface of the blue LED epitaxy and in the third contact hole C3, and a third conductive metal M3 is deposited in the third contact hole C3, so that the third conductive metal M3 fills the third contact hole C3. The third conductive metal M3 in the non-third contact hole C3 is polished and removed by a CMP process to expose the bottom transparent conductive layer D30. The structure is as follows: Figure 4c shown.

[0120] The fourth step is to pattern the vertically bonded multi-layer LED epitaxy into a single LED light-emitting unit through a patterned etching process. Specifically, the etching is performed from top to bottom. The blue LED etching stops at the P electrode position of the blue LED, the green LED etching stops at the P electrode position of the green LED, and the red LED etching stops at the P electrode position of the red LED. Finally, the area between adjacent light-emitting units is etched to a position below the underlying metal bonding layer B0, exposing the P electrode contact holes (the first contact 121, the second contact 122, and the third contact 123) of the three RGB light-emitting units on the underlying drive substrate 10. The structure is as follows: Figure 4d shown.

[0121] In the fifth step, a dielectric protection layer S is deposited on the side wall of the light-emitting unit after etching and patterning, and the dielectric protection layer S is removed at the P electrode (first anode P1) of the red LED and the P electrode contact hole (first contact 121) by etching and patterning to form a conductive P electrode contact hole and a first opening K1. The structure is as follows: Figure 4e shown.

[0122] Step 6: deposit the first conductive layer 101 on the side wall surface of the red LED where the P electrode and the P electrode contact hole are leaking out, and remove the first conductive layer 101 other than the connection between the P electrode and the P electrode contact hole of the red LED by etching and patterning, so as to realize the P electrode and the P electrode contact hole of the red LED to be connected separately, as shown in the structure. Figure 4f shown.

[0123] In the seventh step, a dielectric protection layer S is deposited on the side wall of the light-emitting unit after etching and patterning, and the dielectric protection layer S is removed at the P electrode (second anode P2) and the P electrode contact hole (second contact 122) of the green LED by etching and patterning, forming a conductive P electrode contact hole and a second opening K2. A second conductive layer 102 is deposited on the side wall surface of the green LED where the P electrode and the P electrode contact hole are leaking out, and the second conductive layer 102 other than the connection between the P electrode of the green LED and the P electrode contact hole is removed by etching and patterning, so that the P electrode of the green LED and the P electrode contact hole are independently conductive, and the structure is as follows: Figure 4g shown.

[0124] In the eighth step, a dielectric protection layer S is deposited on the side wall of the light-emitting unit after etching and patterning, and the dielectric protection layer S at the P electrode (third anode P3) of the blue LED and the third contact 123 of the P electrode contact hole is removed by etching and patterning to form a conductive P electrode contact hole and a third opening K3. A third conductive layer 103 is deposited on the side wall surface of the blue LED where the P electrode and the P electrode contact hole are leaking out, and the third conductive layer 103 other than the connection between the P electrode of the blue LED and the P electrode contact hole is removed by etching and patterning to achieve independent conduction between the P electrode of the blue LED and the P electrode contact hole. The structure is as follows: Figure 4h shown.

[0125] The ninth step is to deposit a transparent dielectric protection layer S on the surface of the LED micro display device to protect the LED micro display device as a whole and improve the reliability of the micro display device. The dielectric protection layer S in the PAD area that does not need to be protected is etched away. Figure 2 It should be noted that Figure 2 In the embodiment, there is no third transparent guide layer D3.

[0126] The method for preparing the display device provided in the embodiment of the present application uses silicon-based CMOS as the driving substrate 10. The silicon-based semiconductor process is mature, the process stability is good, and the yield is high. Integrating LEDs into silicon-based CMOS can achieve higher pixel density and lower power consumption. By vertically stacking the R, G, and B pixels, the pixel density can be increased by at least 50% compared to the horizontal arrangement and distribution of RGB pixels. The contact holes are used for vertical connection to increase the effective light-emitting area of ​​the vertically stacked pixels and improve the brightness.

[0127] The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technical personnel in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A display device, characterized in that: The display device comprises: Driver substrate; A first light-emitting unit, bonded to one side of the driving substrate, and comprising a first anode, a first light-emitting layer, a first cathode and a first contact hole, wherein the first contact hole penetrates the first anode, the first light-emitting unit and the first cathode; a second light-emitting unit, bonded to a side of the first light-emitting unit away from the driving substrate, and comprising a second anode, a second light-emitting layer, a second cathode and a second contact hole, wherein the second contact hole penetrates the second anode, the second light-emitting unit and the second cathode; a third light-emitting unit, bonded to a side of the second light-emitting unit away from the driving substrate, and comprising a third anode, a third light-emitting layer, a third cathode and a third contact hole, wherein the third contact hole penetrates the third anode, the third light-emitting unit and the third cathode; Wherein, the first contact hole is connected to the common contact point in the driving substrate, the second contact hole is connected to the first contact hole, and the third contact hole is connected to the second contact hole; The first anode is connected to the common contact in the driving substrate, the second anode is connected to the second contact hole, and the third anode is connected to the third contact hole; Alternatively, the first cathode is connected to the common contact in the driving substrate, the second cathode is connected to the second contact hole, and the third cathode is connected to the third contact hole.

2. The display device according to claim 1, characterized in that The first contact hole includes a first conductive metal and a first dielectric isolation layer between the first conductive metal and the first light emitting unit; The second contact hole includes a second conductive metal and a second dielectric isolation layer located between the second conductive metal and the second light emitting unit; The second contact hole includes a third conductive metal and a third dielectric isolation layer located between the third conductive metal and the third light emitting unit.

3. The display device according to claim 2, characterized in that: The first contact hole is connected to the common contact point in the driving substrate, the second contact hole is connected to the first contact hole, and the third contact hole is connected to the second contact hole; The first cathode is located at a side of the first anode away from the driving substrate, the second anode is located at a side of the second cathode away from the driving substrate, and the third anode is located at a side of the third cathode away from the driving substrate.

4. The display device according to claim 3, characterized in that: The display device comprises: a metal bonding layer, located between the driving substrate and the first anode, and connected to the first conductive metal; a first transparent bonding layer, located between the first cathode and the second cathode; a second transparent bonding layer, located between the second anode and the third cathode; The first transparent bonding layer includes a first sub-bonding layer connected to the first cathode and a second sub-bonding layer connected to the second cathode, the first contact hole also penetrates the first sub-bonding layer, and the second contact hole also penetrates the second sub-bonding layer; The second transparent bonding layer includes a third sub-bonding layer connected to the second anode and a fourth sub-bonding layer connected to the third cathode, and the third contact hole also penetrates the third sub-bonding layer and the fourth sub-bonding layer.

5. The display device according to claim 4, characterized in that: The display device further includes: A first transparent guide layer, located between the first anode and the metal bonding layer; A second transparent guide layer is located on a surface of the second anode facing away from the second cathode and extends between the second dielectric isolation layer and the second conductive metal; The third transparent guide layer is located on the surface of the third anode away from the third cathode and extends between the third dielectric isolation layer and the third conductive metal.

6. The display device according to claim 3, characterized in that: The display device has a step structure at an edge, and the step structure includes a first opening, a second opening, and a third opening respectively exposing the first cathode, the second cathode, and the third cathode; The display device further includes: a first conductive layer connecting a first cathode exposed by the first opening and a first contact in the driving substrate; a second conductive layer connecting a second cathode exposed by the second opening and a second contact in the driving substrate; The third conductive layer connects the third cathode exposed by the third opening and the third contact in the driving substrate.

7. The display device according to claim 6, characterized in that: The step structure includes a first dielectric protection layer, a second dielectric protection layer and a third dielectric protection layer; The first dielectric protection layer covers the edge of the step structure, and the first dielectric protection layer has the first opening and exposes the first contact; the first conductive layer covers the first dielectric protection layer and extends between the first contact and the first cathode below the first opening; The second dielectric protection layer covers the first dielectric protection layer and the first conductive layer, and the second dielectric protection layer and the first dielectric protection layer have the second opening and expose the second contact; the second conductive layer covers the second dielectric protection layer and extends between the second contact and the second cathode below the second opening; The third dielectric protection layer covers the second dielectric protection layer and the second conductive layer, and the third dielectric protection layer, the second dielectric protection layer and the first dielectric protection layer have the third opening and expose the third contact; the third conductive layer covers the third dielectric protection layer and extends between the third contact and the third cathode below the third opening.

8. The display device according to claim 2, characterized in that: The top area of ​​the first contact hole away from the driving substrate is larger than the bottom area of ​​the first contact hole close to the driving substrate; the top area of ​​the second contact hole away from the driving substrate is larger than the bottom area of ​​the second contact hole close to the driving substrate; the top area of ​​the third contact hole away from the driving substrate is larger than the bottom area of ​​the third contact hole close to the driving substrate.

9. The display device according to claim 1, characterized in that: The display device further includes: A first filter layer, located between the first light-emitting unit and the second light-emitting unit; The second filter layer is located between the second light emitting unit and the third light emitting unit.

10. The display device according to claim 1, characterized in that: The driving substrate includes a silicon substrate including a complementary metal oxide semiconductor.

11. The display device according to claim 2, characterized in that: The first cathode is connected to the common contact of the drive substrate, the second cathode is connected to the second contact hole, and the third cathode is connected to the third contact hole; The first anode is located at a side of the first cathode away from the drive substrate, the second cathode is located at a side of the second anode away from the drive substrate, and the third cathode is located at a side of the third anode away from the drive substrate.

12. The display device according to claim 11, characterized in that: The display device comprises: a metal bonding layer, located between the driving substrate and the first cathode and connected to the first conductive metal; a first transparent bonding layer, located between the first anode and the second anode; The second transparent bonding layer is located between the second cathode and the third anode.

13. The display device according to claim 12, characterized in that: The display device further includes: a first transparent guide layer, located between the first anode and the first transparent bonding layer; a second transparent guide layer, located between the second cathode and the second transparent bonding layer, and extending between the second dielectric isolation layer and the second conductive metal; The third transparent guide layer is located on the surface of the third cathode away from the third anode and extends between the third dielectric isolation layer and the third conductive metal.

14. The display device according to claim 11, characterized in that: The display device has a step structure at an edge, and the step structure includes a first opening, a second opening, and a third opening respectively exposing the first anode, the second anode, and the third anode; The display device further includes: a first conductive layer connecting a first anode exposed by the first opening and a first contact in the driving substrate; a second conductive layer connecting the first anode exposed by the second opening and a second contact in the driving substrate; The third conductive layer connects the first anode exposed by the third opening and a third contact in the driving substrate.

15. The display device according to claim 14, characterized in that: The step structure includes a first dielectric protection layer, a second dielectric protection layer and a third dielectric protection layer; The first dielectric protection layer covers the edge of the step structure, and the first dielectric protection layer has the first opening and exposes the first contact; the first conductive layer covers the first dielectric protection layer and extends between the first contact and the first anode below the first opening; The second dielectric protection layer covers the first dielectric protection layer and the first conductive layer, and the second dielectric protection layer and the first dielectric protection layer have the second opening and expose the second contact; the second conductive layer covers the second dielectric protection layer and extends between the second contact and the second anode below the second opening; The third dielectric protection layer covers the second dielectric protection layer and the second conductive layer, and the third dielectric protection layer, the second dielectric protection layer and the first dielectric protection layer have the third opening and expose the third contact; the third conductive layer covers the third dielectric protection layer and extends between the third contact and the third anode below the third opening.

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