Full-color LED display structure and preparation method thereof

Abstract

The invention discloses a full-color LED display structure and a preparation method thereof. The full-color LED display structure comprises at least one light-emitting unit group, each light-emitting unit group comprises first, second and third color light-emitting units; the first color light-emitting unit comprises first and second light-emitting sub-units; the first light-emitting sub-unit and the second light-emitting sub-unit comprise a left side area and a right side area which are connected with each other, each first light-emitting sub-unit corresponds to a second color light-emitting unit, and the vertical projection of the second color light-emitting unit on the first light-emitting sub-unit at least covers part of the left side area of the first light-emitting sub-unit. The second light-emitting sub-units face the left side area of part of the second light-emitting sub-units. Each second sub-light-emitting unit corresponds to one third-color light-emitting unit, and the vertical projection of the third-color light-emitting unit on the second sub-light-emitting unit at least covers the right side area of part of the second sub-light-emitting unit and is right opposite to the right side area of part of the first sub-light-emitting unit. Full-color display can be achieved, and the PPI of the display structure is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a full-color LED display structure and a preparation method thereof. Background Art

[0002] Light-emitting diode (LED) epitaxial wafers have great application prospects in the field of inorganic light-emitting diodes. However, when using epitaxial wafers of different luminous colors to form a tiled or stacked structure to achieve full colorization, there are many difficulties that need to be solved. Summary of the invention

[0003] The invention provides a full-color LED display structure and a preparation method thereof, which can realize full color and improve the luminous efficiency of the device.

[0004] According to one aspect of the present invention, a full-color LED display structure is provided, comprising:

[0005] At least one light emitting unit group; each light emitting unit group includes a first color light emitting unit, a second color light emitting unit and a third color light emitting unit; the third color light emitting unit is located on a side of the second color light emitting unit away from the first color light emitting unit;

[0006] The first color light-emitting unit includes a first sub-light-emitting unit and a second sub-light-emitting unit; the first sub-light-emitting unit and the second sub-light-emitting unit extend along the first direction and are arranged at intervals along the second direction; along the first direction, the first sub-light-emitting unit and the second sub-light-emitting unit include a left area and a right area that are connected to each other, each first sub-light-emitting unit corresponds to a second color light-emitting unit, and the vertical projection of the second color light-emitting unit on the first sub-light-emitting unit at least covers a portion of the left area of ​​the first sub-light-emitting unit and is opposite to the left area of ​​a portion of the second sub-light-emitting unit; each second sub-light-emitting unit corresponds to a third color light-emitting unit, and the vertical projection of the third color light-emitting unit on the second sub-light-emitting unit at least covers a portion of the right area of ​​the second sub-light-emitting unit and is opposite to the right area of ​​a portion of the first sub-light-emitting unit; the vertical projection of the third color light-emitting unit on the second color light-emitting unit does not overlap with the second color light-emitting unit.

[0007] Optionally, the first color light emitting unit is a red light LED unit, the second color light emitting unit is a green light LED unit, and the third color light emitting unit is a blue light LED unit.

[0008] Optionally, the area of ​​the first sub-light-emitting unit is larger than the area of ​​the second color light-emitting unit, and the area of ​​the second sub-light-emitting unit is larger than the area of ​​the third color light-emitting unit.

[0009] Optional, full-color LED display structure also includes:

[0010] An isolation layer, one isolation layer is provided for each light-emitting unit, and the isolation layer is provided around the light-emitting unit;

[0011] A passivation layer, the passivation layer is used to insulate each light-emitting unit;

[0012] The driving substrate is located at a side of the first color light emitting unit away from the third color light emitting unit.

[0013] Optionally, the first sub-light emitting unit and the second sub-light emitting unit include a first semiconductor layer, a first light emitting layer, and a second semiconductor layer stacked in sequence;

[0014] The second color light emitting unit includes a first semiconductor layer, a second light emitting layer, and a second semiconductor layer stacked in sequence;

[0015] The third color light emitting unit comprises a first semiconductor layer, a third light emitting layer and a second semiconductor layer stacked in sequence; the second semiconductor layer is located on a side of the first semiconductor layer away from the driving substrate;

[0016] The driving substrate includes a first electrode contact and a second electrode contact. The first electrode contact is electrically connected to the first semiconductor layer of each light emitting unit, and the second electrode contact is electrically connected to the second semiconductor layer of each light emitting unit.

[0017] Optional, full-color LED display structure also includes:

[0018] A reflective layer, each light-emitting unit corresponds to a reflective layer;

[0019] The reflective layer includes a first reflective layer, a second reflective layer and a third reflective layer; the first reflective layer is located on a side of the first color light emitting unit adjacent to the driving substrate; the second reflective layer is located on a side of the second color light emitting unit adjacent to the driving substrate; the third reflective layer is located on a side of the third color light emitting unit adjacent to the driving substrate.

[0020] According to one aspect of the present invention, there is provided a method for preparing a full-color LED display structure, comprising:

[0021] At least one light-emitting unit group is formed; each light-emitting unit group includes a first color light-emitting unit, a second color light-emitting unit and a third color light-emitting unit; the third color light-emitting unit is located on a side of the second color light-emitting unit away from the first color light-emitting unit;

[0022] The first color light-emitting unit includes a first sub-light-emitting unit and a second sub-light-emitting unit; the first sub-light-emitting unit and the second sub-light-emitting unit extend along the first direction and are arranged at intervals along the second direction; along the first direction, the first sub-light-emitting unit and the second sub-light-emitting unit include a left area and a right area that are connected to each other, each first sub-light-emitting unit corresponds to a second color light-emitting unit, and the vertical projection of the second color light-emitting unit on the first sub-light-emitting unit at least covers a portion of the left area of ​​the first sub-light-emitting unit and is opposite to the left area of ​​a portion of the second sub-light-emitting unit; each second sub-light-emitting unit corresponds to a third color light-emitting unit, and the vertical projection of the third color light-emitting unit on the second sub-light-emitting unit at least covers a portion of the right area of ​​the second sub-light-emitting unit and is opposite to the right area of ​​a portion of the first sub-light-emitting unit; the vertical projection of the third color light-emitting unit on the second color light-emitting unit does not overlap with the second color light-emitting unit.

[0023] Optionally, at least one light emitting unit group is formed, including:

[0024] providing a first substrate;

[0025] A third color light emitting material layer is formed on one side of the first substrate; the third color light emitting material layer comprises a first semiconductor layer, a third light emitting layer and a second semiconductor layer which are stacked in sequence; the first semiconductor layer of the third color light emitting material layer is located on a side of the second semiconductor layer away from the first substrate;

[0026] providing a second substrate;

[0027] A second color light emitting material layer is formed on one side of the second substrate; the second color light emitting material layer comprises a first semiconductor layer, a second light emitting layer and a second semiconductor layer which are sequentially stacked; the first semiconductor layer of the second color light emitting material layer is located on a side of the second semiconductor layer adjacent to the second substrate;

[0028] Removing the second substrate and part of the first semiconductor layer of the second color light-emitting material layer to form a second color light-emitting unit;

[0029] The third color light emitting material layer and the second color light emitting material layer are combined; the second semiconductor layer of the second color light emitting material layer is located on a side of the first semiconductor layer of the second color light emitting material layer adjacent to the first substrate;

[0030] providing a third substrate;

[0031] A first color light emitting material layer is formed on one side of the third substrate; the first color light emitting material layer comprises a first semiconductor layer, a first light emitting layer and a second semiconductor layer stacked in sequence; the first semiconductor layer of the second color light emitting material layer is located on a side of the second semiconductor layer away from the third substrate;

[0032] Removing the third substrate and part of the second semiconductor layer of the first color light emitting material layer to form a first color light emitting unit;

[0033] A first color light emitting material layer and a second color light emitting unit are combined; the first semiconductor layer of the first color light emitting material layer is located on a side of the second semiconductor layer of the first color light emitting material layer adjacent to the first substrate;

[0034] The first substrate and a portion of the second semiconductor layer of the third color light-emitting material layer are removed to form a third color light-emitting unit, thereby forming at least one light-emitting unit group.

[0035] Optionally, before removing the third substrate and forming the first color light emitting unit, the method further includes:

[0036] forming a driving substrate;

[0037] A driving substrate and a first color light emitting material layer are combined; the first semiconductor layer of the first color light emitting material layer is located on a side of the second semiconductor layer of the first color light emitting material layer adjacent to the driving substrate.

[0038] Optionally, after forming the third color light emitting material layer on one side of the first substrate, the method further includes:

[0039] forming a third reflective layer on a side of the third color light emitting unit adjacent to the driving substrate;

[0040] After forming a second color light emitting material layer on one side of the second substrate, the method further comprises:

[0041] forming a second reflective layer on a side of the second color light emitting unit adjacent to the driving substrate;

[0042] After forming a first color light emitting material layer on one side of the third substrate, the method further includes:

[0043] A first reflective layer is formed on a side of the third color light emitting unit adjacent to the driving substrate, and the first reflective layer, the second reflective layer and the third reflective layer are reflective layers.

[0044] In the technical solution of the embodiment of the present invention, the first color light-emitting unit, the second color light-emitting unit and the third color light-emitting unit can realize full-color display; the second color light-emitting unit, the left area of ​​the second sub-light-emitting unit opposite to the second color light-emitting unit and the third color light-emitting unit form a first pixel; the second color light-emitting unit, the third color light-emitting unit and the right area of ​​the first sub-light-emitting unit opposite to the third color light-emitting unit form a second pixel; the first pixel and the second pixel form a light-emitting unit group, and the first pixel and the second pixel share the second color light-emitting unit and the third color light-emitting unit. In the actual display process, one light-emitting unit group is displayed as two pixels, which can achieve a two-fold increase in PPI and improve the PPI of the display structure.

[0045] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0047] Figure 1 It is a schematic diagram of a full-color LED display structure provided by an embodiment of the present invention.

[0048] Figure 2 This is a light emitting unit arrangement diagram provided by an embodiment of the present invention.

[0049] Figure 3 This is a first color light emitting unit arrangement diagram provided by an embodiment of the present invention.

[0050] Figure 4 This is another light emitting unit arrangement diagram provided by an embodiment of the present invention.

[0051] Figure 5 The present invention provides a flowchart of a method for preparing a full-color LED display structure.

[0052] Figure 6 yes Figure 5 A detailed flow chart included in S100.

[0053] Figure 7-Figure 21 It is a schematic diagram of the intermediate structure of a full-color LED display structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0055] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0056] The embodiment of the present invention provides a full-color LED display structure. Figure 1 is a structural schematic diagram of a full-color LED display structure provided by an embodiment of the present invention, Figure 2 is a light emitting unit arrangement diagram provided by an embodiment of the present invention, refer to Figure 1 and Figure 2 , full-color LED display structure includes:

[0057] At least one light emitting unit group 100; each light emitting unit group 100 includes a first color light emitting unit 10, a second color light emitting unit 20 and a third color light emitting unit 30; the third color light emitting unit 30 is located on a side of the second color light emitting unit 20 away from the first color light emitting unit 10;

[0058] The first color light-emitting unit 10 includes a first sub-light-emitting unit 11 and a second sub-light-emitting unit 12; the first sub-light-emitting unit 11 and the second sub-light-emitting unit 12 extend along the first direction X and are arranged at intervals along the second direction Y; along the first direction X, the first sub-light-emitting unit 11 and the second sub-light-emitting unit 12 include a left area and a right area connected to each other, each first sub-light-emitting unit 11 corresponds to a second color light-emitting unit 20, and the vertical projection of the second color light-emitting unit 20 on the first sub-light-emitting unit 11 at least covers a portion of the left area of ​​the first sub-light-emitting unit 11, and is opposite to the left area of ​​a portion of the second sub-light-emitting unit 12; each second sub-light-emitting unit 12 corresponds to a third color light-emitting unit 30, and the vertical projection of the third color light-emitting unit 30 on the second sub-light-emitting unit 12 at least covers a portion of the right area of ​​the second sub-light-emitting unit 12, and is opposite to the right area of ​​a portion of the first sub-light-emitting unit 11; the vertical projection of the third color light-emitting unit 30 on the second color light-emitting unit 20 does not overlap with the second color light-emitting unit 20.

[0059] Among them, the side walls of the first color light-emitting unit 10, the second color light-emitting unit 20 and the third color light-emitting unit 30 can be inclined side walls to improve the light-emitting efficiency. The first color light-emitting unit 10, the second color light-emitting unit 20 and the third color light-emitting unit 30 are stacked vertically in sequence, which can reduce the lateral size of the device. For example, the first color light-emitting unit 10 can be a red light LED unit, the second color light-emitting unit 20 can be a green light LED unit, and the third color light-emitting unit 30 can be a blue light LED unit. Since the light-emitting efficiency of red light is relatively low, the number of the first color light-emitting units 10 can be set to be twice the number of the second color light-emitting units 20 or twice the number of the third color light-emitting units 30, so as to improve the light-emitting efficiency of the first color light, thereby realizing full-color display.

[0060] Specifically, the arrangement of the light emitting units in the embodiment of the present invention is as follows: Figure 2 As shown, each first sub-light-emitting unit 11 corresponds to a second color light-emitting unit 20, and each second sub-light-emitting unit 12 corresponds to a third color light-emitting unit 30. Along the first direction X, the length of the first sub-light-emitting unit 11 is greater than the length of the second color light-emitting unit 20, the length of the second sub-light-emitting unit 12 is greater than the length of the third color light-emitting unit 30, and the length of each sub-light-emitting unit is greater than the sum of the length of the second color light-emitting unit 20 and the length of the third color light-emitting unit 30; along the second direction Y, the width of each first sub-light-emitting unit 11 can be less than, equal to, or greater than the width of the second color light-emitting unit 20, and the width of each second sub-light-emitting unit 12 can be less than, equal to, or greater than the width of the third color light-emitting unit 30. The embodiment of the present invention does not specifically limit the width of the sub-light-emitting unit; along the first direction X, the first sub-light-emitting unit 11 and the second sub-light-emitting unit 12 include mutually The left and right areas of the connected sub-light emitting unit 11 and the second sub-light emitting unit 12 are opposite to each other in the two left areas and the two right areas; the second color light emitting unit 20, the left area of ​​the second sub-light emitting unit 12 opposite to the second color light emitting unit 20 and the third color light emitting unit 30 form the first pixel 13; the second color light emitting unit 20, the third color light emitting unit 30 and the right area of ​​the first sub-light emitting unit 11 opposite to the third color light emitting unit 30 form the second pixel 14; the first pixel 13 and the second pixel 14 form a light emitting unit group 100, and the first pixel 13 and the second pixel 14 share the second color light emitting unit 20 and the third color light emitting unit 30. In the actual display process, one light emitting unit group 100 is displayed as two pixels, which can achieve a two-fold increase in PPI and improve the PPI of the display structure; wherein, PPI, namely Pixels Per Inch, is also called the pixel density unit, which represents the number of pixels per inch. Therefore, the higher the PPI value, the higher the density at which the display screen can display images; the higher the display density, the higher the degree of realism.

[0061] In the technical solution of the embodiment of the present invention, the first color light-emitting unit 10, the second color light-emitting unit 20 and the third color light-emitting unit 30 can be used to realize full-color display; the second color light-emitting unit 20, the left area of ​​the second sub-light-emitting unit 12 opposite to the second color light-emitting unit 20 and the third color light-emitting unit 30 form a first pixel 13; the second color light-emitting unit 20, the third color light-emitting unit 30 and the right area of ​​the first sub-light-emitting unit 11 opposite to the third color light-emitting unit 30 form a second pixel 14; the first pixel 13 and the second pixel 14 form a light-emitting unit group 100, and the first pixel 13 and the second pixel 14 share the second color light-emitting unit 20 and the third color light-emitting unit 30. In the actual display process, one light-emitting unit group 100 is displayed as two pixels, which can achieve a two-fold increase in PPI and improve the PPI of the display structure.

[0062] Optional, reference Figure 1 and Figure 2 The first color light emitting unit 10 is a red light LED unit, the second color light emitting unit 20 is a green light LED unit, and the third color light emitting unit 30 is a red light LED unit.

[0063] Among them, since the red light LED unit has a low luminous efficiency, setting the first color light-emitting unit 10 as a red light LED unit can improve the luminous efficiency of red light and achieve full-color display; the blue light LED unit, the green light LED unit and the red light LED unit can all be made of GaN-based materials. In other embodiments, the red light LED unit can also be made of gallium arsenide materials; the blue light LED unit, the green light LED unit and the red light LED unit can realize the colorization of the LED structure and achieve full-color display.

[0064] Optional, reference Figure 1 and Figure 2 , the area of ​​the first sub-light-emitting unit 11 is larger than the area of ​​the second color light-emitting unit 20 , and the area of ​​the second sub-light-emitting unit 12 is larger than the area of ​​the third color light-emitting unit 30 .

[0065] Among them, the area of ​​the first sub-light-emitting unit 11 is larger than the area of ​​the second color light-emitting unit 20, and the area of ​​the second sub-light-emitting unit 12 is larger than the area of ​​the third color light-emitting unit 30, which can improve the luminous efficiency of the first color light, thereby realizing full-color display.

[0066] Optional, reference Figure 1The full-color LED display structure also includes: an isolation layer 40, each light-emitting unit is correspondingly provided with an isolation layer 40, and the isolation layer 40 is arranged around the light-emitting unit; a passivation layer 50, and the passivation layer 50 is used to insulate each light-emitting unit; a driving substrate 60, and the driving substrate 60 is located on the side of the first color light-emitting unit 10 away from the third color light-emitting unit 30.

[0067] The isolation layer 40 is an opaque layer. The material of the isolation layer 40 can be tungsten or other metals or black resin. The isolation layer 40 surrounds each light-emitting unit. Figure 3 is a first color light emitting unit arrangement diagram provided by an embodiment of the present invention, referring to Figure 3 , the isolation layer 40 surrounds the first sub-light emitting unit 11, and the isolation layer 40 surrounds the second sub-light emitting unit 12; Figure 4 is another arrangement diagram of light emitting units provided in an embodiment of the present invention, refer to Figure 4 The isolation layer 40 surrounds the second color light emitting unit 20, and the isolation layer 40 surrounds the third color light emitting unit 30; the isolation layer 40 is used to avoid optical crosstalk between adjacent light emitting units, which can prevent the occurrence of optical crosstalk problems. Figure 3 This is just one example.

[0068] The driving substrate 60 can be an IC driving chip or a CMOS driving backplane; the first color light-emitting unit 10 can be bonded to the driving substrate 60 through a hybrid bonding process; the driving substrate 60 can include multiple driving units, and the multiple driving units independently control the first color light-emitting unit 10, the second color light-emitting unit 20 and the third color light-emitting unit 30, and the light-emitting units will not affect each other after the voltage is applied, so full-color display can be achieved and the luminous efficiency is improved.

[0069] The material of the passivation layer 50 can be silicon dioxide or transparent resin, etc.; the passivation layer 50 is located between the driving substrate 60 and the first color light-emitting unit 10, between adjacent sub-light-emitting units, between the first color light-emitting unit 10 and the second color light-emitting unit 20, and between the second color light-emitting unit 20 and the third color light-emitting unit 30; if the full-color LED display structure includes multiple light-emitting unit groups 100, the passivation layer 50 is also located between adjacent first color light-emitting units 10, between adjacent second color light-emitting units 20 and between adjacent third color light-emitting units 30, and the passivation layer 50 can play a role of insulation protection; subsequently, a through hole can be set in the passivation layer 50, and a conductive bonding point can be formed after the through hole is filled with metal to realize the electrical connection between the driving substrate 60 and each light-emitting unit.

[0070] Optional, reference Figure 1The first sub-light-emitting unit 11 and the second sub-light-emitting unit 12 include a first semiconductor layer 15, a first light-emitting layer 16 and a second semiconductor layer 17 stacked in sequence; the second color light-emitting unit 20 includes a first semiconductor layer 15, a second light-emitting layer 18 and a second semiconductor layer 17 stacked in sequence; the third color light-emitting unit 30 includes a first semiconductor layer 15, a third light-emitting layer 19 and a second semiconductor layer 17 stacked in sequence; the second semiconductor layer 17 is located on the side of the first semiconductor layer 15 away from the driving substrate 60; the driving substrate 60 includes a first electrode contact 61 and a second electrode contact 62, the first electrode contact 61 is electrically connected to the first semiconductor layer 15 of each light-emitting unit, and the second electrode contact 62 is electrically connected to the second semiconductor layer 17 of each light-emitting unit.

[0071] The first semiconductor layer 15 and the second semiconductor layer 17 have different conductivity types, one of which is an N-type doped semiconductor layer and the other is a P-type doped semiconductor layer. The materials of the first semiconductor layer 15 and the second semiconductor layer 17 include one or more materials of AlN, GaN, AlGaN or InGaN. The first electrode contact 61 is electrically connected to the first semiconductor layer 15 of each light-emitting unit, that is, the first electrode contact 61 is electrically connected to the first semiconductor layer 15 of the first sub-light-emitting unit 11, the first semiconductor layer 15 of the second sub-light-emitting unit 12, the first semiconductor layer 15 of the second color light-emitting unit 20, and the first semiconductor layer 15 of the third color light-emitting unit 30; the second electrode contact 62 is electrically connected to the second semiconductor layer 17 of each light-emitting unit, that is, the second electrode contact 62 is electrically connected to the second semiconductor layer 17 of the first sub-light-emitting unit 11, the second semiconductor layer 17 of the second sub-light-emitting unit 12, the second semiconductor layer 17 of the second color light-emitting unit 20, and the second semiconductor layer 17 of the third color light-emitting unit 30.

[0072] The full-color LED display structure also includes a first conductive layer and a second conductive layer. The first conductive layer can be located on the side of the first semiconductor layer 15 adjacent to the driving substrate 60. The first conductive layer at least partially covers each first semiconductor layer 15. The material of the first conductive layer can be an indium tin oxide (ITO) film. The indium tin oxide film has good conductivity and visible light transmittance. The first conductive layer is electrically connected to the first electrode contact 61 of the driving substrate 60, so that the driving unit in the driving substrate 60 provides an electrical signal to each light-emitting unit through the first conductive layer; the second conductive layer 70 is located on the side of the second semiconductor layer 17 of each light-emitting unit away from the driving substrate 60. The second conductive layer 70 at least partially covers part of the second semiconductor layer 17. The second conductive layer 70 is electrically connected to the second electrode contact 62 of the driving substrate 60, so that the driving unit in the driving substrate 60 provides an electrical signal to each light-emitting unit through the second conductive layer 70. Figure 1In the structure in FIG. 1 , the electrical signal of the second conductive layer 70 is continuous, and the second electrode contact 62 is electrically connected to the second conductive layer 70 through the conductive bonding point.

[0073] Optionally, the full-color LED display structure also includes: a reflective layer, each light-emitting unit corresponds to a reflective layer; the reflective layer includes a first reflective layer 81, a second reflective layer 82 and a third reflective layer 83; the first reflective layer 81 is located on the side of the first color light-emitting unit 10 adjacent to the driving substrate 60; the second reflective layer 82 is located on the side of the second color light-emitting unit 20 adjacent to the driving substrate 60; the third reflective layer 83 is located on the side of the third color light-emitting unit 30 adjacent to the driving substrate 60.

[0074] The first reflective layer 81 is used to reflect the light of the first color; the second reflective layer 82 is used to transmit the light of the first color and reflect the light of the second color; the third reflective layer 83 is used to transmit the light of the first color and reflect the light of the third color, thereby improving the utilization rate of light. If a first conductive layer is provided, the first conductive layer is located between the reflective layer and the first semiconductor layer 15.

[0075] The embodiment of the present invention provides a method for preparing a full-color LED display structure based on the above embodiment, which is used to prepare the full-color LED display structure described in any embodiment of the present invention; Figure 5 is a flow chart of a method for preparing a full-color LED display structure provided by an embodiment of the present invention, with reference to Figure 5 , the preparation method comprises:

[0076] S100, forming at least one light-emitting unit group; each light-emitting unit group includes a first color light-emitting unit, a second color light-emitting unit and a third color light-emitting unit; the third color light-emitting unit is located on a side of the second color light-emitting unit away from the first color light-emitting unit; the first color light-emitting unit includes a first sub-light-emitting unit and a second sub-light-emitting unit; the first sub-light-emitting unit and the second sub-light-emitting unit extend along the first direction and are arranged at intervals along the second direction; along the first direction, the first sub-light-emitting unit and the second sub-light-emitting unit include a left area and a right area that are connected to each other, each first sub-light-emitting unit corresponds to a second color light-emitting unit, and the vertical projection of the second color light-emitting unit on the first sub-light-emitting unit at least covers a portion of the left area of ​​the first sub-light-emitting unit and is opposite to the left area of ​​a portion of the second sub-light-emitting unit; each second sub-light-emitting unit corresponds to a third color light-emitting unit, and the vertical projection of the third color light-emitting unit on the second sub-light-emitting unit at least covers a portion of the right area of ​​the second sub-light-emitting unit and is opposite to the right area of ​​a portion of the first sub-light-emitting unit; the vertical projection of the third color light-emitting unit on the second color light-emitting unit does not overlap with the second color light-emitting unit.

[0077] In the preparation method provided by the technical solution of the embodiment of the present invention, the first color light-emitting unit, the second color light-emitting unit and the third color light-emitting unit can realize full-color display; the second color light-emitting unit, the left area of ​​the second sub-light-emitting unit opposite to the second color light-emitting unit and the third color light-emitting unit form a first pixel; the second color light-emitting unit, the third color light-emitting unit and the right area of ​​the first sub-light-emitting unit opposite to the third color light-emitting unit form a second pixel; the first pixel and the second pixel form a light-emitting unit group, and the first pixel and the second pixel share the second color light-emitting unit and the third color light-emitting unit. In the actual display process, one light-emitting unit group is displayed as two pixels, which can achieve a two-fold increase in PPI and improve the PPI of the display structure.

[0078] Optional, Figure 6 yes Figure 5 A detailed flow chart included in S100, Figure 7-Figure 15 1 is a schematic diagram of an intermediate structure of a full-color LED display structure provided by an embodiment of the present invention. S100: forming at least one light-emitting unit group, including:

[0079] S110 , providing a first substrate.

[0080] Among them, reference Figure 7 , a first buffer layer 02 is formed on the first substrate 01.

[0081] S120, forming a third color light-emitting material layer on one side of the first substrate; the third color light-emitting material layer includes a first semiconductor layer, a third light-emitting layer and a second semiconductor layer stacked in sequence; the first semiconductor layer of the third color light-emitting material layer is located on a side of the second semiconductor layer away from the first substrate.

[0082] Among them, reference Figure 7 , a third color luminescent material layer is formed on the first buffer layer 02, the third color luminescent material layer includes a first semiconductor layer 15, a third luminescent layer 19, a second semiconductor layer 17 and a third reflective layer 83 which are stacked in sequence, and the third color luminescent material layer covers the first buffer layer 02; Figure 8 , the third color light emitting material layer is etched by photolithography, so that the second semiconductor layer 17 of the third color material layer is partially etched away, and the remaining part completely covers the first buffer layer 02. Then, the isolation layer 40 is formed; after the isolation layer 40 is formed, the first passivation layer 51 is formed, and the first passivation layer 51 covers the isolation layer 40, the third reflective layer 83, the first semiconductor layer 15, the side wall of the third light emitting layer 19 and part of the second semiconductor layer 17; then, the first conductive bonding point A1 is formed, and the first conductive bonding point A1 covers part of the third reflective layer 83.

[0083] S130, providing a second substrate.

[0084] Among them, reference Fig. 9 , a second buffer layer 05 is formed on the second substrate 04 .

[0085] S140, forming a second color light-emitting material layer on one side of the second substrate; the second color light-emitting material layer includes a first semiconductor layer, a second light-emitting layer, and a second semiconductor layer stacked in sequence; the first semiconductor layer of the second color light-emitting material layer is located on a side of the second semiconductor layer adjacent to the second substrate.

[0086] Among them, reference Fig. 9 , a second color luminescent material layer is formed on the second buffer layer 05, the second color luminescent material layer includes a first semiconductor layer 15, a second luminescent layer 18, a second semiconductor layer 17 and a second reflective layer 82 which are stacked in sequence, and the second color luminescent material layer covers the second buffer layer 05; the second color luminescent material layer is etched by photolithography, so that a part of the first semiconductor layer 15 of the second color material layer is etched away, and the remaining part covers the second buffer layer 05. Then, an isolation layer 40 is formed; then, a second passivation layer 52 is formed, and the second passivation layer 52 covers the second conductive layer 70, the isolation layer 40, the second semiconductor layer 17, the sidewall of the second luminescent layer 18 and a part of the first semiconductor layer 15; and then, a second conductive bonding point A2 is formed. Reference Fig.10 A second sub-substrate 03 is formed on a side of the second passivation layer 52 away from the second substrate 04 , and the material of the second sub-substrate 03 may be silicon.

[0087] S150, removing the second substrate and part of the first semiconductor layer of the second color light-emitting material layer to form a second color light-emitting unit.

[0088] Among them, reference Fig.10 and Fig.11 , remove the second substrate 04, the second buffer layer 05 and part of the second semiconductor layer 17 covering the second buffer layer 05 to form a second color light-emitting unit, and then form a second conductive layer 70 of the second color light-emitting unit. After forming the second conductive layer 70, form a second passivation sublayer 521.

[0089] S160, combining the third color light-emitting material layer and the second color light-emitting material layer; the second semiconductor layer of the second color light-emitting material layer is located on a side of the first semiconductor layer of the second color light-emitting material layer adjacent to the first substrate.

[0090] Among them, reference Fig.12 The first passivation layer 51 and the second passivation sublayer 521 are bonded by fusion bonding to form a third passivation layer 53, wherein the third passivation layer 53 includes the first passivation layer 51, the second passivation layer 52 and the second passivation sublayer 521, and the third color luminescent material layer and the second color luminescent material layer are combined; Fig.13, then remove the second sub-substrate 03, form a third conductive bonding point A3 in the third passivation layer 53, part of the third conductive bonding point A3 is electrically connected to the second conductive bonding point A2, and part of the third conductive bonding point A3 is electrically connected to the second conductive layer 70 of the second color light-emitting unit 20, and the second conductive layers 70 on the same layer are electrically connected.

[0091] S170 , providing a third substrate.

[0092] Among them, reference Fig.14 , a third buffer layer 08 is formed on the third substrate 07 .

[0093] S180, forming a first color light-emitting material layer on one side of the third substrate; the first color light-emitting material layer includes a first semiconductor layer, a first light-emitting layer and a second semiconductor layer stacked in sequence; the first semiconductor layer of the first color light-emitting material layer is located on a side of the second semiconductor layer away from the third substrate.

[0094] Among them, reference Fig.14 A first color luminescent material layer is formed on the third buffer layer 08, the first color luminescent material layer covers the third buffer layer 08, and the first color luminescent material layer includes a first semiconductor layer 15, a first luminescent layer 16, a second semiconductor layer 17 and a first reflective layer 81 which are stacked in sequence. Fig.15 , the first color light emitting material layer is etched by photolithography, so that part of the second semiconductor layer 17 of the first color material layer is etched away, and the remaining part covers the third buffer layer 08. Then, the isolation layer 40 is formed; then the fourth passivation layer 54 is formed, and the fourth passivation layer 54 covers the isolation layer 40, the first reflective layer 81, the first semiconductor layer 15, the side wall of the first light emitting layer 16 and part of the second semiconductor layer 17; then, the fourth conductive bonding point A4 is formed, and the fourth conductive bonding point A4 covers part of the first reflective layer 81.

[0095] S190, removing the third substrate and part of the second semiconductor layer of the first color light-emitting material layer to form a first color light-emitting unit.

[0096] Among them, reference Fig.16 , before removing the third substrate and part of the second semiconductor layer of the first color light-emitting material layer to form the first color light-emitting unit, it also includes: forming a driving substrate 60, forming a first electrode contact 61 and a second electrode contact 62 on the driving substrate 60; then forming a fifth passivation layer 55 and a fifth conductive bonding point A5, and the fifth conductive bonding point A5 and the fourth conductive bonding point A4 are correspondingly arranged; refer to Fig.17Then, the driving substrate 60 and the first color light emitting material layer are combined, and the fifth conductive bonding point A5 and the fourth conductive bonding point A4 are bonded by a hybrid bonding method, and the fifth passivation layer 55 and the fourth passivation layer 54 are bonded, and the fifth passivation layer 55 and the fourth passivation layer 54 form a sixth passivation layer 56; Fig.18 , then remove the third substrate 07, the third buffer layer 08 and a portion of the second semiconductor layer 17 covering the third buffer layer 08 to form a first color light emitting unit 10; then form a second conductive layer 70 and a seventh passivation layer 57 of the first color light emitting unit 10; refer to Fig.19 , the seventh passivation layer 57 is etched to form a sixth conductive bonding point A6, part of the sixth conductive bonding point A6 is electrically connected to part of the first electrode contact 61, and part of the sixth conductive bonding point A6 is electrically connected to the second conductive layer 70 of the first color light-emitting unit 10.

[0097] S200, combining a first color light-emitting material layer and a second color light-emitting unit; the first semiconductor layer of the first color light-emitting material layer is located on a side of the second semiconductor layer of the first color light-emitting material layer adjacent to the first substrate.

[0098] Among them, reference Fig. 20 By hybrid bonding the seventh passivation layer 57 and the third passivation layer 53, and bonding the third conductive bonding point A3 and the sixth conductive bonding point A6, the first color light emitting material layer and the second color light emitting unit 20 are combined. The bonded seventh passivation layer 57, the third passivation layer 53 and the sixth passivation layer 56 are the passivation layer 50 in the embodiment of the present invention.

[0099] S210 , removing the first substrate and a portion of the second semiconductor layer of the third color light-emitting material layer to form a third color light-emitting unit, thereby forming at least one light-emitting unit group.

[0100] Among them, reference Fig.21 , remove the first substrate 01 and the first buffer layer 02 and a portion of the second semiconductor layer 17 covering the first buffer layer 02 to form a third color light emitting unit 30, referring to Figure 1 , a second conductive layer 70 of the third color light emitting unit is formed on the third color light emitting unit 30 , and at least one light emitting unit group 100 is formed.

[0101] The embodiment of the present invention adopts the method of melt bonding and hybrid bonding to prepare the three-layer light-emitting unit stack, and finally performs hybrid bonding, which has a simple process, a large process window and a high yield.

[0102] Optionally, before removing the third substrate and forming the first color light emitting unit, the method further includes:

[0103] forming a driving substrate;

[0104] A driving substrate and a first color light emitting material layer are combined; the first semiconductor layer of the first color light emitting material layer is located on a side of the second semiconductor layer of the first color light emitting material layer adjacent to the driving substrate.

[0105] This step has been described in detail in the above step S190.

[0106] Optionally, after S120, forming a third color light emitting material layer on one side of the first substrate, the method further includes:

[0107] A third reflective layer is formed on a side of the third color light emitting unit adjacent to the driving substrate.

[0108] This step has been described in detail in the above step S120.

[0109] S140, after forming a second color light emitting material layer on one side of the second substrate, further comprising:

[0110] forming a second reflective layer on a side of the second color light emitting unit adjacent to the driving substrate;

[0111] This step has been described in detail in the above step S140.

[0112] S180, after forming a first color light emitting material layer on one side of the third substrate, further comprising:

[0113] A first reflective layer is formed on a side of the third color light emitting unit adjacent to the driving substrate, and the first reflective layer, the second reflective layer and the third reflective layer are reflective layers.

[0114] This step has been described in detail in the above step S180.

[0115] The method for preparing the full-color LED display structure provided by the technical solution of the embodiment of the present invention has the same beneficial effects as the full-color LED display structure described in any embodiment of the present invention.

[0116] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

Claims

1. A full-color LED display structure, characterized in that: include: At least one light emitting unit group; each of the light emitting unit groups includes a first color light emitting unit, a second color light emitting unit and a third color light emitting unit; The third color light emitting unit is located on a side of the second color light emitting unit away from the first color light emitting unit; The first color light-emitting unit includes a first sub-light-emitting unit and a second sub-light-emitting unit; the first sub-light-emitting unit and the second sub-light-emitting unit extend along the first direction and are arranged at intervals along the second direction; along the first direction, the first sub-light-emitting unit and the second sub-light-emitting unit include a left area and a right area that are connected to each other, each of the first sub-light-emitting units corresponds to a second color light-emitting unit, and the vertical projection of the second color light-emitting unit on the first sub-light-emitting unit at least covers a portion of the left area of ​​the first sub-light-emitting unit and is opposite to the left area of ​​a portion of the second sub-light-emitting unit; each of the second sub-light-emitting units corresponds to a third color light-emitting unit, and the vertical projection of the third color light-emitting unit on the second sub-light-emitting unit at least covers a portion of the right area of ​​the second sub-light-emitting unit and is opposite to the right area of ​​a portion of the first sub-light-emitting unit; the vertical projection of the third color light-emitting unit on the second color light-emitting unit does not overlap with the second color light-emitting unit.

2. The full-color LED display structure according to claim 1, characterized in that: The first color light emitting unit is a red light LED unit, the second color light emitting unit is a green light LED unit, and the third color light emitting unit is a blue light LED unit.

3. The full-color LED display structure according to claim 2, characterized in that: The area of ​​the first sub-light emitting unit is larger than the area of ​​the second color light emitting unit, and the area of ​​the second sub-light emitting unit is larger than the area of ​​the third color light emitting unit.

4. The full-color LED display structure according to claim 1, characterized in that: Also includes: An isolation layer, one isolation layer is provided for each light-emitting unit, and the isolation layer is provided around the light-emitting unit; A passivation layer, the passivation layer is used to insulate each light-emitting unit; A driving substrate is located on a side of the first color light emitting unit away from the third color light emitting unit.

5. The full-color LED display structure according to claim 4, characterized in that: The first sub-light emitting unit and the second sub-light emitting unit include a first semiconductor layer, a first light emitting layer, and a second semiconductor layer stacked in sequence; The second color light emitting unit comprises a first semiconductor layer, a second light emitting layer, and a second semiconductor layer stacked in sequence; The third color light emitting unit comprises a first semiconductor layer, a third light emitting layer and a second semiconductor layer stacked in sequence; the second semiconductor layer is located on a side of the first semiconductor layer away from the driving substrate; The driving substrate includes a first electrode contact and a second electrode contact, the first electrode contact is electrically connected to the first semiconductor layer of each of the light-emitting units, and the second electrode contact is electrically connected to the second semiconductor layer of each of the light-emitting units.

6. The full-color LED display structure according to claim 4, characterized in that: Also includes: A reflective layer, each light-emitting unit corresponds to a reflective layer; The reflective layer includes a first reflective layer, a second reflective layer and a third reflective layer; the first reflective layer is located on a side of the first color light-emitting unit adjacent to the driving substrate; the second reflective layer is located on a side of the second color light-emitting unit adjacent to the driving substrate; and the third reflective layer is located on a side of the third color light-emitting unit adjacent to the driving substrate.

7. A method for preparing a full-color LED display structure, characterized in that: include: Forming at least one light emitting unit group; each of the light emitting unit groups includes a first color light emitting unit, a second color light emitting unit and a third color light emitting unit; The third color light emitting unit is located on a side of the second color light emitting unit away from the first color light emitting unit; The first color light-emitting unit includes a first sub-light-emitting unit and a second sub-light-emitting unit; the first sub-light-emitting unit and the second sub-light-emitting unit extend along the first direction and are arranged at intervals along the second direction; along the first direction, the first sub-light-emitting unit and the second sub-light-emitting unit include a left area and a right area that are connected to each other, each of the first sub-light-emitting units corresponds to a second color light-emitting unit, and the vertical projection of the second color light-emitting unit on the first sub-light-emitting unit at least covers a portion of the left area of ​​the first sub-light-emitting unit and is opposite to the left area of ​​a portion of the second sub-light-emitting unit; each of the second sub-light-emitting units corresponds to a third color light-emitting unit, and the vertical projection of the third color light-emitting unit on the second sub-light-emitting unit at least covers a portion of the right area of ​​the second sub-light-emitting unit and is opposite to the right area of ​​a portion of the first sub-light-emitting unit; the vertical projection of the third color light-emitting unit on the second color light-emitting unit does not overlap with the second color light-emitting unit.

8. The preparation method according to claim 7, characterized in that: At least one light emitting unit group is formed, comprising: providing a first substrate; A third color light emitting material layer is formed on one side of the first substrate; the third color light emitting material layer comprises a first semiconductor layer, a third light emitting layer and a second semiconductor layer which are stacked in sequence; the first semiconductor layer of the third color light emitting material layer is located on a side of the second semiconductor layer away from the first substrate; providing a second substrate; A second color light emitting material layer is formed on one side of the second substrate; the second color light emitting material layer comprises a first semiconductor layer, a second light emitting layer and a second semiconductor layer which are sequentially stacked; the first semiconductor layer of the second color light emitting material layer is located on a side of the second semiconductor layer adjacent to the second substrate; removing part of the first semiconductor layer of the second substrate and the second color light-emitting material layer to form a second color light-emitting unit; The third color light emitting material layer and the second color light emitting material layer are combined; the second semiconductor layer of the second color light emitting material layer is located on a side of the first semiconductor layer of the second color light emitting material layer adjacent to the first substrate; providing a third substrate; A first color light emitting material layer is formed on one side of the third substrate; the first color light emitting material layer comprises a first semiconductor layer, a first light emitting layer, and a second semiconductor layer which are sequentially stacked; the first semiconductor layer of the second color light emitting material layer is located on a side of the second semiconductor layer away from the third substrate; Removing the third substrate and part of the second semiconductor layer of the first color light-emitting material layer to form a first color light-emitting unit; The first color light emitting material layer and the second color light emitting unit are combined; the first semiconductor layer of the first color light emitting material layer is located on a side of the second semiconductor layer of the first color light emitting material layer adjacent to the first substrate; Part of the second semiconductor layer of the first substrate and the third color light-emitting material layer is removed to form a third color light-emitting unit, thereby forming at least one light-emitting unit group.

9. The preparation method according to claim 8, characterized in that: Before removing the third substrate and forming the first color light emitting unit, the method further includes: forming a driving substrate; The driving substrate and the first color light-emitting material layer are combined; the first semiconductor layer of the first color light-emitting material layer is located on a side of the second semiconductor layer of the first color light-emitting material layer adjacent to the driving substrate.

10. The preparation method according to claim 9, characterized in that: After forming a third color light emitting material layer on one side of the first substrate, the method further includes: forming a third reflective layer on a side of the third color light emitting unit adjacent to the driving substrate; After forming a second color light emitting material layer on one side of the second substrate, the method further includes: forming a second reflective layer on a side of the second color light emitting unit adjacent to the driving substrate; After forming a first color light emitting material layer on one side of the third substrate, the method further includes: A first reflective layer is formed on a side of the third color light emitting unit adjacent to the driving substrate, and the first reflective layer, the second reflective layer and the third reflective layer are reflective layers.

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