CN116190526A

CN116190526A - Light-emitting element, light-emitting element and preparation method of display panel

Info

Publication number: CN116190526A
Application number: CN202111435546.6A
Authority: CN
Inventors: 董小彪; 黄秀颀; 盛翠翠; 李蒙蒙; 高文龙; 林佳桦; 葛泳; 王程功; 钱先锐
Original assignee: Chengdu Vistar Optoelectronics Co Ltd
Current assignee: Chengdu Vistar Optoelectronics Co Ltd
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2023-05-30

Abstract

The invention relates to the technical field of display panels, and discloses a light-emitting element, a light-emitting element and a preparation method of a display panel. When the growth substrate irradiates laser, namely, a laser stripping process is performed, the shading structure can shade the laser between the adjacent light emitting units, and the part of the laser is prevented from irradiating the bonding layer on the temporary substrate, so that the degree of the influence of the laser of the bonding layer can be reduced, and the yield of the laser stripping process can be improved.

Description

Light-emitting element, light-emitting element and preparation method of display panel

Technical Field

The present invention relates to the field of display panels, and in particular, to a light emitting device, and a method for manufacturing a display panel.

Background

The Micro-LED display technology has the advantages of high brightness, high response speed, low power consumption, long service life and the like, and gradually becomes a research hot spot of a new generation of display technology. The Micro-LED display technology relates to a batch transfer process of LED chips, and hundreds of thousands of LED chips are transferred onto a driving backboard with high efficiency and high yield.

The batch transfer process for Micro-LEDs includes a Laser Lift-off (LLO) process. However, in the current laser lift-off process, the temporary bonding adhesive layer on the temporary substrate for transferring the LED chip is easily affected by the laser, resulting in a low yield of the current laser lift-off process.

Disclosure of Invention

In view of the above, the present invention mainly solves the technical problem of providing a light emitting device, a light emitting device and a method for manufacturing a display panel, which can improve the yield of the laser lift-off process.

In order to solve the technical problems, the invention adopts a technical scheme that: a light emitting element is provided. The light emitting element includes a growth substrate. The light-emitting element further comprises at least two light-emitting units, and the at least two light-emitting units are arranged on the growth substrate along a preset direction. The light-emitting element further comprises a light shielding structure, wherein the light shielding structure is arranged on the growth substrate along a preset direction and is positioned on the same side of the growth substrate with the at least two light-emitting units; the orthographic projection of the shading structure on the reference plane is positioned between orthographic projections of adjacent light emitting units on the reference plane, and the reference plane is perpendicular to the preset direction.

In order to solve the technical problems, the invention adopts another technical scheme that: a method for manufacturing a light emitting element is provided. The preparation method comprises the following steps: and forming a shading structure and at least two light-emitting units on the growth substrate, wherein the shading structure and the at least two light-emitting units are arranged on the growth substrate along a preset direction and are positioned on the same side of the growth substrate, orthographic projections of the shading structure on a reference plane are positioned between orthographic projections of adjacent light-emitting units on the reference plane, and the reference plane is perpendicular to the preset direction.

In order to solve the technical problems, the invention adopts another technical scheme that: a method for manufacturing a display panel is provided. The preparation method comprises the following steps: a light-emitting element was produced according to the production method described in the above examples; bonding at least two light emitting units of the light emitting element with a bonding layer on the first temporary substrate; irradiating laser on one side of the growth substrate of the light-emitting element, which is away from the first temporary substrate, so as to transfer the at least two light-emitting units to the first temporary substrate; and transferring the light emitting units on the first temporary substrate to a driving backboard.

The beneficial effects of the invention are as follows: the invention provides a light-emitting element, a light-emitting element and a preparation method of a display panel. When the growth substrate irradiates laser, namely, a laser stripping process is performed, the shading structure can shade the laser between the adjacent light emitting units, and the part of the laser is prevented from irradiating the bonding layer on the temporary substrate (namely, the first temporary substrate), so that the degree of influence of the laser of the bonding layer can be reduced, and the yield of the laser stripping process can be improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. Furthermore, these drawings and the written description are not intended to limit the scope of the inventive concept in any way, but to illustrate the inventive concept to those skilled in the art by referring to the specific embodiments.

FIG. 1 is a schematic flow chart of a first embodiment of a method for manufacturing a light-emitting device according to the present invention;

FIG. 2 is a schematic flow chart of a second embodiment of a method for manufacturing a light-emitting device according to the present invention;

FIGS. 3a-3b are schematic structural views of steps in the preparation method shown in FIG. 2;

FIG. 4 is a schematic flow chart of a third embodiment of a method for fabricating a light-emitting device according to the present invention;

FIGS. 5a-5c are schematic structural views of steps in the preparation method shown in FIG. 4;

FIG. 6 is a schematic flow chart of a fourth embodiment of a method for manufacturing a light-emitting device according to the present invention;

FIGS. 7a-7b are schematic structural views of steps in the preparation method shown in FIG. 6;

FIG. 8 is a schematic flow chart of an embodiment of a method for manufacturing a display panel according to the present invention;

FIGS. 9a-9d are schematic structural views of steps in the preparation method shown in FIG. 8;

FIG. 10 is a schematic flow chart of another embodiment of a method for manufacturing a display panel according to the present invention;

FIGS. 11a-11d are schematic structural views showing steps in the production method shown in FIG. 10;

fig. 12 is a schematic structural view of a first embodiment of a light emitting element of the present invention;

fig. 13 is a schematic structural view of a second embodiment of the light emitting element of the present invention;

fig. 14 is a schematic structural view of a third embodiment of a light emitting element of the present invention;

FIG. 15 is a schematic diagram of an embodiment of a driving back plate according to the present invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described in the following in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. The following embodiments and features of the embodiments may be combined with each other without conflict.

Referring to fig. 1, fig. 1 is a schematic flow chart of a first embodiment of a method for manufacturing a light emitting device according to the present invention.

S101: and forming a shading structure and at least two light emitting units on the growth substrate.

In this embodiment, the growth substrate is a growth substrate of a light emitting unit, and at least a part of structures related to manufacturing the light emitting unit are formed on the growth substrate. The at least two light-emitting units are arranged on the growth substrate along a preset direction, namely, the at least two light-emitting units and the growth substrate are stacked along the preset direction. Specifically, the light emitting unit of the present embodiment is directly formed on the growth substrate. Of course, in other embodiments of the present invention, a portion of the structure related to the light emitting unit may be formed on the growth substrate, and the rest of the structure related to the light emitting unit may be formed in other process steps.

In addition, the present embodiment also forms a light shielding structure on the growth substrate. The shading structure is arranged on the growth substrate along a preset direction, namely the shading structure and the growth substrate are laminated along the preset direction. The shading structure and the at least two light emitting units are positioned on the same side of the growth substrate. The orthographic projection of the shading structure on the reference plane is positioned between orthographic projections of adjacent light emitting units on the reference plane, and the reference plane is perpendicular to the preset direction. In this way, the light shielding structure can shield the laser between the adjacent light emitting units in the laser peeling process.

In the related art, however, laser light between adjacent light emitting units cannot be blocked, and the portion of the laser light may be irradiated to a bonding layer on a temporary substrate (i.e., a first temporary substrate described below) through an area between the adjacent light emitting units. Since the bonding layer is generally made of a photosensitive material, the adhesive force provided by the bonding layer is reduced by irradiation with a laser having a specific wavelength. The laser passing between the adjacent light emitting units is refracted and reflected after reaching the bonding layer, which is easy to cause light side etching, namely, part of the laser irradiates the bonding part of the bonding layer and the light emitting units, so that the bonding force of the bonding part is reduced, and the light emitting units on the first temporary substrate are easy to fall off, so that the yield of the laser stripping process is reduced.

As can be seen from the above, the present embodiment provides a method for manufacturing a light-emitting element. The preparation method forms a shading structure on a growth substrate. When the growth substrate is far away from the side of the temporary substrate and irradiates laser, a laser stripping process is performed, the shading structure can shade laser between adjacent light emitting units, and the part of laser is prevented from irradiating the bonding layer on the temporary substrate, so that the degree of influence of the laser of the bonding layer can be reduced, and the yield of the laser stripping process can be improved.

Referring to fig. 2 and fig. 3a-3b, fig. 2 is a schematic flow chart of a second embodiment of a method for manufacturing a light emitting device according to the present invention, and fig. 3a-3b are schematic structural diagrams of steps in the manufacturing method shown in fig. 2. In the method for manufacturing a light emitting element according to the present embodiment, the light shielding structure is formed together when at least a part of the structure related to manufacturing the light emitting unit is formed.

S201: at least two epitaxial cells are formed on a growth substrate.

In the present embodiment, the light emitting unit 20 is directly formed on the growth substrate 10. Specifically, as shown in fig. 3a, at least two epitaxial cells 21 are first formed on a growth substrate 10. The different epitaxial cells 21 are spaced apart from each other on the growth substrate 10. The epitaxial cells 21 may be obtained from an entire epitaxial layer by etching. The epitaxial unit 21 generally includes a P-type semiconductor layer, a quantum well layer, an N-type semiconductor layer, etc., which are understood by those skilled in the art, and will not be described herein.

Alternatively, the growth substrate 10 may be a sapphire substrate or the like, which is not limited herein.

S202: a metal structure is formed on each epitaxial cell and between adjacent epitaxial cells.

In this embodiment, as shown in fig. 3b, a metal structure 30 is formed on each epitaxial cell 21 and between adjacent epitaxial cells 21. In other words, a portion of the metal structure 30 is located on the side of the epitaxial cells 21 facing away from the growth substrate 10, and the remaining portion of the metal structure 30 is located on the growth substrate 10 between adjacent epitaxial cells 21.

The light emitting unit 20 is composed of the epitaxial unit 21 and the metal structure 30 thereon, and the metal structure 30 on the epitaxial unit 21 is used as the electrode 22 of the light emitting unit 20 for electrically connecting with the driving circuit on the driving back plate 40. The metal structures 30 between adjacent epitaxial cells 21 form a light shielding structure a, i.e. the metal structures 30 between adjacent epitaxial cells 21 serve as light shielding structures a. The light shielding structure a and the light emitting unit 20 are located on the same side of the growth substrate 10. That is, the present embodiment forms the light shielding structure a together when forming the electrode 22 of the light emitting unit 20. The light shielding structure A and the electrode 22 of the light emitting unit 20 are formed by the same process, so that the influence of the process for manufacturing the light shielding structure A on the original process of manufacturing the light emitting unit 20 can be reduced.

The at least two light emitting units 20 are disposed on the growth substrate 10 along a predetermined direction (as indicated by arrow X in fig. 3b, the same applies hereinafter), i.e., the at least two light emitting units 20 are stacked with the growth substrate 10 along the predetermined direction. The light shielding structure a is disposed on the growth substrate 10 along the predetermined direction, that is, the light shielding structure a and the growth substrate 10 are stacked along the predetermined direction. And, the light shielding structure a is located on the same side of the growth substrate 10 as the light emitting unit 20. The orthographic projection of the light shielding structure a on the reference plane (as indicated by plane α in fig. 3b, the same applies hereinafter) is located between orthographic projections of adjacent light emitting units 20 on the reference plane. In this way, the light shielding structure a can shield the laser light between the adjacent light emitting units 20 in the laser lift-off process.

Alternatively, in the present embodiment, the light shielding structure a is the same as the electrode 22 of the light emitting unit 20, and the metal structure 30 may be a metal with good light blocking performance, for example, the metal structure 30 is made of at least one of gold, silver, copper, and the like. The metal structure 30 may be formed on the growth substrate 10 by a thermal evaporation process. The thickness of the metal structure 30 may be 0.5 μm to 3 μm to ensure that the metal structure 30 has sufficient light blocking properties. In addition, the metal structure 30 has a mesh shape.

Of course, in other embodiments of the present invention, the light shielding structure a may not be formed in the same process as the electrode 22 of the light emitting unit 20, for example, the light shielding structure a may be separately manufactured before or after forming the light emitting unit 20. In this case, the light shielding structure a may be made of an organic gel material or an inorganic material having good light blocking performance, such as PI (polyimide), epoxy resin, polyurethane, etc., in addition to the foregoing metal materials, and is not limited thereto.

As can be seen from the above, the present embodiment forms the light shielding structure a together when the electrode 22 of the light emitting unit 20 is formed. When the laser lift-off process is performed, the light shielding structure a can shield the laser between the adjacent light emitting units 20, and prevent the laser from irradiating the bonding layer on the temporary substrate, so that the degree of influence of the laser on the bonding layer can be reduced, and the yield of the laser lift-off process can be improved. In addition, the yield of the laser stripping process in the prior art is not more than 10%, and the yield of the laser stripping process in the embodiment can reach more than 99%.

Referring to fig. 4 and fig. 5a-5c, fig. 4 is a schematic flow chart of a third embodiment of a method for manufacturing a light emitting device according to the present invention, and fig. 5a-5c are schematic structural diagrams of steps in the manufacturing method shown in fig. 4. In the method for manufacturing a light emitting element according to the present embodiment, the light shielding structure is formed together when at least a part of the structure related to manufacturing the light emitting unit is formed.

S301: a sacrificial layer and an epitaxial layer are sequentially formed on a growth substrate.

In the present embodiment, the light emitting unit 20 is directly formed on the growth substrate 10. Specifically, as shown in fig. 5a, a sacrificial layer 23 and an epitaxial layer 24 are first sequentially formed on a growth substrate 10. In the laser lift-off process, the laser irradiates the sacrificial layer 23 between the epitaxial layer 24 and the growth substrate 10, so that the sacrificial layer 23 is decomposed, and thus the epitaxial layer 24 and the growth substrate 10 are lifted off. Epitaxial layer 24 generally includes P-type semiconductor layers, quantum well layers, N-type semiconductor layers, etc., which are well understood by those skilled in the art and will not be described in detail herein.

The sacrificial layer 23 and the epitaxial layer 24 are of a whole-layer structure, namely, the sacrificial layer 23 and the epitaxial layer 24 are laid on the growth substrate 10 in a whole-layer mode.

Alternatively, the sacrificial layer 23 has good light blocking properties, and the sacrificial layer 23 may be a laser decomposition layer, such as a GaN layer, etc., which is not limited herein. The thickness of the sacrificial layer 23 may be 1 μm to 10 μm to ensure that the sacrificial layer 23 has sufficient light blocking properties. Further, the sacrifice layer 23 has a mesh shape.

S302: the epitaxial layer is patterned to form at least two epitaxial cells.

In this embodiment, as shown in fig. 5a and 5b, the epitaxial layer 24 is subjected to patterning treatment, that is, ISO etching is performed on the epitaxial layer 24 to separate at least two epitaxial cells 21 spaced apart from each other, and each epitaxial cell 21 is used for the subsequent formation of the light emitting cell 20.

It should be noted that, in this embodiment, only the epitaxial layer 24 is patterned, and the sacrificial layer 23 is remained, that is, the sacrificial layer 23 between the adjacent epitaxial units 21 is remained. The sacrificial layer 23 between adjacent epitaxial units 21, i.e., the sacrificial layer 23 between adjacent light emitting units 20 described below, forms a light shielding structure a, which shields the laser light at a subsequent laser lift-off stage.

S303: electrodes are formed on the respective epitaxial cells.

In this embodiment, as shown in fig. 5c, after patterning the epitaxial layer 24 to form at least two epitaxial units 21, an electrode 22 is formed on each epitaxial unit 21, that is, each epitaxial unit 21 and the electrode 22 thereon form the light emitting unit 20, so that the light emitting unit 20 is completed, and a subsequent transfer process of the light emitting unit 20 is required.

As can be seen from the above, the sacrificial layer 23 between the adjacent light emitting units 20 forms the light shielding structure a, which can shield the laser between the adjacent light emitting units 20, prevent the laser from irradiating the bonding layer on the temporary substrate, reduce the influence of the laser on the bonding layer, and further improve the yield of the laser lift-off process. The sacrificial layer 23 is laid over the entire growth substrate 10, and can block the laser light to the maximum extent and reduce the laser light irradiated to the bonding layer 51 to the maximum extent. In addition, the sacrificial layer 23 can be completely decomposed by irradiation of laser light, and the growth substrate 10 can be easily peeled off.

Referring to fig. 6 and fig. 7a-7b, fig. 6 is a schematic flow chart of a fourth embodiment of a method for manufacturing a light emitting device according to the present invention, and fig. 7a-7b are schematic structural diagrams of steps in the manufacturing method shown in fig. 6.

S401: at least two light emitting units are formed on the growth substrate.

In the present embodiment, as shown in fig. 7a, at least two light emitting units 20 are directly formed on a growth substrate 10. The process of forming the light emitting unit 20 is understood by those skilled in the art, and will not be described herein.

S402: a light shielding material layer is formed on a growth substrate.

In the present embodiment, as shown in fig. 7b, a light shielding material layer 70 is formed on the growth substrate 10. Wherein the light shielding material layer 70 covers the light emitting units 20 and the growth substrate 10 between adjacent light emitting units 20.

The light shielding material layer 70 between adjacent light emitting cells 20 forms a light shielding structure a. The light shielding structure a and the light emitting unit 20 are located on the same side of the growth substrate 10. The light shielding structure a can shield the laser between the adjacent light emitting units 20, can prevent the laser from irradiating the bonding layer on the temporary substrate, can reduce the influence of the laser on the bonding layer, and can further improve the yield of the laser lift-off process.

Alternatively, the material of the light shielding material layer 70 may be photoresist with light blocking property. The thickness of the light shielding material layer 70 may be 0.1 μm to 10 μm to ensure that the light shielding material layer 70 has sufficient light blocking performance. The light shielding material layer 70 has a mesh shape.

S403: the light shielding material layer is patterned to expose the electrodes of the light emitting units.

In this embodiment, as shown in fig. 7b, the light shielding material layer 70 is patterned to expose the electrode 22 of the light emitting unit 20, so as to ensure that the electrode 22 of the light emitting unit 20 can be electrically connected to the driving circuit on the driving back plate.

As can be seen from the above, the present embodiment uses the light shielding material layer 70 as the light shielding structure a. When the laser lift-off process is performed, the light shielding structure a can shield the laser between the adjacent light emitting units 20, and prevent the laser from irradiating the bonding layer on the temporary substrate, so that the degree of influence of the laser on the bonding layer can be reduced, and the yield of the laser lift-off process can be improved.

Referring to fig. 8 and fig. 9a-9d, fig. 8 is a schematic flow chart of an embodiment of a method for manufacturing a display panel according to the present invention, and fig. 9a-9d are schematic structural diagrams of each step in the manufacturing method shown in fig. 8.

S501: a light-emitting element was prepared.

In this embodiment, the light-emitting element is manufactured according to the manufacturing method of the light-emitting element described in the above embodiment, and will not be described here again.

Specifically, as shown in fig. 9a, the light emitting element includes a growth substrate 10.

The light emitting element further comprises at least two light emitting units 20. The at least two light emitting units 20 are disposed on the growth substrate 10 along a predetermined direction, that is, the at least two light emitting units 20 and the growth substrate 10 are stacked along the predetermined direction.

The light-emitting element further includes a light shielding structure a disposed on the growth substrate 10 along the predetermined direction, that is, the light shielding structure a and the growth substrate 10 are stacked along the predetermined direction. And, the light shielding structure a is located on the same side of the growth substrate 10 as the light emitting unit 20.

It should be noted that, in the above embodiment, the light shielding structure a is formed by taking the light shielding material layer 70 between the adjacent light emitting units 20 as an example, which is only needed for discussion, and the forming manner of the light shielding structure a is not limited.

S502: at least two light emitting units of the light emitting element are bonded to a bonding layer on the first temporary substrate.

In the present embodiment, as shown in fig. 9b, a first temporary substrate 50 is provided, and a bonding layer 51 is formed on the first temporary substrate 50, the bonding layer 51 being used to temporarily bond the light emitting units 20 on the growth substrate 10. In order to peel the at least two light emitting units 20 formed as described above from the growth substrate 10, it is necessary to bond the growth substrate 10 and the first temporary substrate 50 such that the at least two light emitting units 20 formed as described above are bonded to the bonding layer 51 on the first temporary substrate 50 for the subsequent laser peeling process.

Alternatively, the bonding layer 51 may be made of a photosensitive adhesive material, which may have a phenomenon of decreasing adhesion under irradiation of a laser with a specific wavelength. Specifically, the bonding layer 51 may be made of a triazene polymer, polyimide, or the like. The thickness of the bonding layer 51 may be 1 μm to 1mm. In addition, the bonding layer 51 is entirely laid on the first temporary substrate 50.

S503: and irradiating laser on one side of the growth substrate of the light-emitting element, which is away from the first temporary substrate, so as to transfer at least two light-emitting units to the first temporary substrate.

In the present embodiment, as shown in fig. 9b and 9c, after the light emitting unit 20 is bonded to the bonding layer 51 on the first temporary substrate 50, a laser lift-off process may be performed. Specifically, laser light is irradiated on a side of the growth substrate 10 facing away from the first temporary substrate 50 to transfer the at least two light emitting units 20 formed as described above to the first temporary substrate 50. The light shielding structure a can shield the laser light between the adjacent light emitting units 20, prevent the laser light from being irradiated to the bonding layer 51 on the first temporary substrate 50, reduce the influence of the laser light on the bonding layer 51, and improve the yield of the laser lift-off process.

Alternatively, the laser lift-off process of the present embodiment may employ excimer laser or laser output from a solid state laser, etc., and the wavelength of the laser may be 248nm or 266nm, etc. The bonding layer 51 may employ a photosensitive material such as a triazene polymer or the like. The first temporary substrate 50 may be made of glass, sapphire, or the like.

Note that the light shielding material layer 70 on the micro light emitting device 20 remains during the transfer of the light emitting unit 20 to the first temporary substrate 50. The remaining light shielding material layer 70 covers other areas of the surface of the micro light emitting device 20 facing the first temporary substrate 50 than the area occupied by the electrode 22. In this way, after the micro light emitting device 20 of the present embodiment is transferred to the driving back plate 40, the reserved light shielding material layer 70 can avoid the crosstalk of the light beams output by the adjacent micro light emitting devices 20, which is beneficial to reducing the packaging difficulty of the micro light emitting devices 20.

S504: and transferring the light emitting units on the first temporary substrate to the driving backboard.

In the present embodiment, as shown in fig. 9d, after transferring the above-described at least two light emitting units 20 to the first temporary substrate 50, the light emitting units 20 on the first temporary substrate 50 are transferred to the driving back plate 40. The driving back plate 40 is integrated with a driving circuit (not shown), and the light emitting unit 20 is electrically connected to the driving circuit, and the driving circuit is used for driving the light emitting unit 20 to emit light for display.

Further, a plurality of stopper structures 80 are formed on the driving back plate 40. Wherein, a limit groove 81 is formed between adjacent limit structures 80. The limit groove 81 exposes the solder 41 on the driving back plate 40 for electrically connecting the light emitting unit 20, and the electrode 22 of the light emitting unit 20 is electrically connected to the driving circuit board through the solder 41.

Alternatively, ACF (Anisotropic Conductive Film ), metal solder, or the like may be used as the solder 41, and indium, tin, indium tin alloy, or the like may be used as the solder 41.

In the present embodiment, the light emitting unit 20 is transferred into the limit groove 81. In this embodiment, the position of the light emitting unit 20 on the driving back plate 40 is limited by the limiting groove 81, so that the risk of thermal mismatch, sliding, crystal breakage and other problems of the light emitting unit 20 in the process of being electrically connected with the driving back plate 40 is reduced.

Alternatively, the stopper 80 may be made of a photoresist, such as PDMS (Polydimethylsiloxane). The thickness of the limiting structure 80 is 0.5 μm to 50 μm, and by reasonably setting the thickness of the limiting structure 80, that is, reasonably setting the size of the limiting groove 81, the limiting groove 81 can reliably limit the micro light emitting device 20 and ensure that the electrode 22 of the micro light emitting device 20 can contact the solder 41. In addition, the limiting structure 80 is in a grid shape.

The limit structure 80 and the limit groove 81 are formed by spin-coating a photoresist on the driving back plate 40, and performing processes such as baking, exposure, and development. Also, the spacing structure 80 may have a viscosity and/or elasticity, i.e., the spacing structure 80 has at least one of a viscosity and elasticity. The limiting structure 80 has viscosity, and can temporarily fix the light emitting unit 20 after the light emitting unit 20 is transferred to the limiting groove 81, so as to further reduce the sliding risk of the light emitting unit 20. And the limit structure 80 has elasticity, can play the cushioning effect to the light emitting unit 20 in the process that the light emitting unit 20 is transferred to the limit groove 81, reduces the impact force received by the light emitting unit 20, and is favorable for guaranteeing the transfer yield of the light emitting unit 20.

In the present embodiment, the solder 41 is melted by the high-voltage reflow soldering process, and thus the light emitting unit 20 is reliably bonded to the driving circuit and electrical connection between the two is established, that is, the light emitting unit 20 is electrically connected to the driving circuit.

Alternatively, the driving backplate 40 may employ LTPS (Low Temperature Poly-Silicon, low temperature polysilicon) technology, IGZO (Indium Gallium Zinc Oxide ) technology, LTPO (Low Temperature Polycrystalline Oxide, low temperature polysilicon oxide) technology, or the like.

Referring to fig. 10 and fig. 11a to 11d, fig. 10 is a schematic flow chart of another embodiment of a method for manufacturing a display panel according to the present invention, and fig. 11a to 11d are schematic structural diagrams of each step in the manufacturing method shown in fig. 10. Fig. 10 shows a specific process of step S504 in the above embodiment.

S5041: at least two first temporary substrates are provided.

In this embodiment, as shown in fig. 11a, at least two first temporary substrates 50 are provided, wherein the luminescent colors of the luminescent units 20 on different first temporary substrates 50 are different, the luminescent colors of the luminescent units 20 on the same first temporary substrate 50 are the same, and the luminescent units 20 on each first temporary substrate 50 can be obtained by the above-mentioned method steps. For example, the display device generally includes the light emitting units 20 with three light emitting colors of red, green and blue, so the present embodiment can provide three first temporary substrates 50, and the light emitting colors of the light emitting units 20 on each first temporary substrate 50 are sequentially red, green and blue.

S5042: the light emitting units of the first temporary substrates are transferred to the second temporary substrate.

In this embodiment, as shown in fig. 11b and 11c, after the light emitting units 20 are transferred to the first temporary substrates 50, the electrodes 22 of the light emitting units 20 for electrically connecting the driving circuit are bonded to the bonding layer 51, and at this time, the electrode 22 of the light emitting units 20 need to be turned around, and thus cannot be directly transferred to the driving back plate 40, and it is necessary to transfer the light emitting units 20 of the respective first temporary substrates 50 to the second temporary substrates 60, that is, turn around the electrode 22 of the light emitting units 20 through the second temporary substrates 60, so that the electrode 22 of the light emitting units 20 faces away from the second temporary substrates 60, so that the electrode 22 of the light emitting units 20 is electrically connected to the driving circuit.

Further, each light emitting unit 20 of each light emitting color has a corresponding mounting position on the driving back plate 40, that is, the light emitting unit 20 of the corresponding light emitting color needs to be correctly mounted on the corresponding mounting position on the driving back plate 40. In order to integrate the light emitting units 20 with multiple light emitting colors on the driving back plate 40, the present embodiment selectively transfers the light emitting units 20 of each first temporary substrate 50 to the second temporary substrate 60, the positions of the transferred light emitting units 20 on each first temporary substrate 50 on the second temporary substrate 60 are consistent with the positions of the corresponding driving back plate 40, and then transfers the light emitting units 20 on the second temporary substrate 60 to the driving back plate 40.

In other words, the present embodiment avoids the transfer procedure of transferring the light emitting units 20 of each first temporary substrate 50 to the driving back plate 40 by selectively transferring the light emitting units 20 of each first temporary substrate 50 to the same second temporary substrate 60 and uniformly transferring the light emitting units 20 of each first temporary substrate 50 to the driving back plate 40 through the second temporary substrate 60, thereby reducing the number of transfer procedures, being beneficial to improving the efficiency of the batch transfer process of the light emitting units 20 and avoiding the yield loss caused by more transfers of the light emitting units 20.

S5043: and transferring the light emitting units on the second temporary substrate to the driving backboard.

In the present embodiment, as shown in fig. 11d, after the light emitting units 20 of each first temporary substrate 50 are selectively transferred to the second temporary substrate 60, the light emitting units 20 on the second temporary substrate 60 are transferred to the driving back plate 40.

Referring to fig. 12, fig. 12 is a schematic structural diagram of a light emitting device according to a first embodiment of the present invention.

In an embodiment, the light emitting element may be applied to a batch transfer process of the light emitting unit 20. Further, the light emitting element is used to transfer the light emitting unit 20 to the driving back plate. The light emitting unit 20 may be a Micro LED (Micro light emitting diode) or the like.

The light emitting element comprises a growth substrate 10. Alternatively, the growth substrate 10 may be a sapphire substrate or the like, which is not limited herein.

The light emitting element further comprises at least two light emitting units 20. The at least two light emitting units 20 are disposed on the growth substrate 10 along a predetermined direction (as indicated by arrow X in fig. 12, the same applies hereinafter), i.e., the at least two light emitting units 20 are stacked with the growth substrate 10 along the predetermined direction.

The orthographic projection of the light shielding structure a on the reference plane is located between orthographic projections of adjacent light emitting units 20 on the reference plane. In this way, when the growth substrate 10 is irradiated with laser light, that is, the laser lift-off process is performed, the light shielding structure a can shield the laser light between the adjacent light emitting units 20, and prevent the part of the laser light from being irradiated to the bonding layer on the temporary substrate (i.e., the first temporary substrate), so that the degree of influence of the laser light on the bonding layer can be reduced, and the yield of the laser lift-off process can be improved.

Please continue to refer to fig. 12. In an embodiment, the material of the light shielding structure a is the same as the material of at least part of the structure of the light emitting element. In other words, the light shielding structure a and at least part of the light emitting element are formed by the same process, so that the influence of the process for manufacturing the light shielding structure a on the original process of manufacturing the light emitting unit 20 can be reduced.

Specifically, the light shielding structure a is a metal structure 30, and the electrode 22 on the light emitting unit 20 is a metal structure 30. In other words, the light emitting element further comprises a metal structure 30. The metal structure 30 is provided on the growth substrate 10 between the light emitting units 20 and the adjacent light emitting units 20. In other words, a portion of the metal structure 30 is located on a side of the light emitting cells 20 facing away from the growth substrate 10, and the remaining portion of the metal structure 30 is located on the growth substrate 10 between adjacent light emitting cells 20.

The metal structure 30 on the light emitting unit 20 is the electrode 22 of the light emitting unit 20, and is used for electrically connecting with the driving circuit on the driving back plate 40. The metal structure 30 on the growth substrate 10 between adjacent light emitting cells 20 is a light shielding structure a. The light shielding structure a and the light emitting unit 20 are located on the same side of the growth substrate 10. The present embodiment forms the light shielding structure a together when forming the electrode 22 of the light emitting unit 20. The light shielding structure A and the electrode 22 of the light emitting unit 20 are formed by the same process, so that the influence of the process for manufacturing the light shielding structure A on the original process of manufacturing the light emitting unit 20 can be reduced.

Referring to fig. 13, fig. 13 is a schematic structural diagram of a light emitting device according to a second embodiment of the invention.

In an alternative embodiment, the light emitting element further comprises a sacrificial layer 23. The at least two light emitting units 20 described above are connected to the growth substrate 10 through the sacrificial layer 23. The sacrificial layer 23 between adjacent light emitting cells 20 forms a light shielding structure a. The light shielding structure a and the light emitting unit 20 are located on the same side of the growth substrate 10. In this embodiment, the part of the sacrificial layer 23 is used as the light shielding structure a, that is, the light shielding structure a is formed together in the process of manufacturing the sacrificial layer 23, so that the influence of the process of manufacturing the light shielding structure a on the original process of manufacturing the light emitting unit 20 can be reduced.

The light shielding structure a can shield the laser between the adjacent light emitting units 20, can prevent the laser from irradiating the bonding layer on the temporary substrate, can reduce the influence of the laser on the bonding layer, and can further improve the yield of the laser lift-off process. The sacrificial layer 23 is laid over the entire growth substrate 10, and can block the laser light to the maximum extent and reduce the laser light irradiated to the bonding layer 51 to the maximum extent. In addition, the sacrificial layer 23 can be completely decomposed by irradiation of laser light, and the growth substrate 10 can be easily peeled off.

Referring to fig. 14, fig. 14 is a schematic structural diagram of a light emitting device according to a third embodiment of the invention.

In one embodiment, the light emitting element further includes a light shielding material layer 70. The light shielding material layer 70 covers the light emitting cells 20 and the growth substrate 10 between adjacent light emitting cells 20. The light shielding material layer 70 between adjacent light emitting cells 20 serves as a light shielding structure a. The light shielding structure a and the light emitting unit 20 are located on the same side of the growth substrate 10. The light shielding structure a can shield the laser between the adjacent light emitting units 20, can prevent the laser from irradiating the bonding layer on the temporary substrate, can reduce the influence of the laser on the bonding layer, and can further improve the yield of the laser lift-off process.

Further, the light shielding material layer 70 exposes the electrode 22 of the light emitting unit 20, so as to ensure that the electrode 22 of the light emitting unit 20 can be electrically connected to the driving circuit on the driving back plate.

It should be noted that, during the process of transferring the light emitting unit 20 from the growth substrate 10 to the temporary substrate (i.e., the first temporary substrate described above), the light shielding material layer 70 on the light emitting unit 20 remains. The remaining light shielding material layer 70 covers other areas of the surface of the light emitting unit 20 facing the temporary substrate than the area occupied by the electrode 22. In this way, after the light emitting units 20 are transferred to the driving back plate, the reserved light shielding material layer 70 can avoid the crosstalk of the light rays output by the adjacent light emitting units 20, which is beneficial to reducing the packaging difficulty of the light emitting units 20.

Referring to fig. 15, fig. 15 is a schematic structural diagram of a driving back plate according to an embodiment of the invention.

In one embodiment, the driving back plate 40 is provided with a plurality of limiting structures 80. Wherein, a limit groove 81 is arranged between the adjacent limit structures 80. The limiting groove 81 is used for accommodating the light emitting unit 20 transferred to the driving back plate 40, and the position of the light emitting unit 20 on the driving back plate 40 is limited by the limiting groove 81 in the embodiment, so that the risk of thermal mismatch, sliding, crystal breakage and other problems of the light emitting unit 20 in the process of being electrically connected with the driving back plate 40 is reduced.

In addition, in the present invention, unless explicitly specified and limited otherwise, the terms "connected," "stacked," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. A light-emitting element, comprising:

growing a substrate;

at least two light-emitting units arranged on the growth substrate along a preset direction;

the shading structure is arranged on the growth substrate along the preset direction and is positioned on the same side of the growth substrate as the light emitting unit;

the orthographic projection of the shading structure on the reference plane is positioned between the orthographic projections of the adjacent light emitting units on the reference plane, and the reference plane is perpendicular to the preset direction.

2. A light-emitting element according to claim 1, wherein,

the shading structure is a metal structure;

wherein, the electrode on the light-emitting unit is of a metal structure;

preferably, the metal structure is made of at least one of gold, silver and copper, the thickness of the metal structure is 0.5-3 μm, and the metal structure is in a grid shape.

3. A light-emitting element according to claim 1, wherein,

the at least two light emitting units are connected with the growth substrate through a sacrificial layer;

wherein the shading structure is a sacrificial layer between adjacent light emitting units;

preferably, the material of the sacrificial layer is gallium nitride, the thickness of the sacrificial layer is 1-10 μm, and the sacrificial layer is in a grid shape.

4. A light-emitting element according to claim 1, wherein,

the shading structure is a shading material layer;

wherein the light-emitting unit is covered with the shading material layer;

preferably, the light shielding material layer exposes an electrode of the light emitting unit;

preferably, the material of the light shielding material layer is photoresist with light blocking performance, the thickness of the light shielding material layer is 0.1 μm to 10 μm, and the light shielding material layer is in a grid shape.

5. A method of manufacturing a light-emitting element, the method comprising:

forming a shading structure and at least two light emitting units on a growth substrate;

the light shielding structure and the at least two light emitting units are arranged on the growth substrate and located on the same side of the growth substrate along a preset direction, orthographic projections of the light shielding structure on a reference plane are located between orthographic projections of adjacent light emitting units on the reference plane, and the reference plane is perpendicular to the preset direction.

6. The method according to claim 5, wherein,

the step of forming the light shielding structure and the at least two light emitting units on the growth substrate comprises the following steps:

forming at least two epitaxial units on the growth substrate;

forming a metal structure on each epitaxial unit and between adjacent epitaxial units, wherein the epitaxial units and the metal structures on the epitaxial units form the light-emitting units, and the metal structures between the adjacent epitaxial units form the light-shielding structures;

7. The method according to claim 5, wherein,

forming a sacrificial layer and an epitaxial layer on the growth substrate in sequence;

patterning the epitaxial layer to form at least two epitaxial units, wherein the sacrificial layer between adjacent epitaxial units forms the shading structure;

forming an electrode on each of the epitaxial cells;

8. The method according to claim 5, wherein,

forming the at least two light emitting units on the growth substrate;

forming a light shielding material layer on the growth substrate, wherein the light shielding material layer covers the light emitting units and the growth substrate between adjacent light emitting units, and the light shielding structure is formed by the light shielding material layer between adjacent light emitting units;

preferably, the step of forming a light shielding material layer on the growth substrate includes: patterning the light shielding material layer to expose the electrode of the light emitting unit;

9. A method for manufacturing a display panel, the method comprising:

preparing a light-emitting element according to the preparation method of any one of claims 5 to 8;

bonding at least two light emitting units of the light emitting element with a bonding layer on the first temporary substrate;

irradiating laser on one side of the growth substrate of the light-emitting element, which is away from the first temporary substrate, so as to transfer the at least two light-emitting units to the first temporary substrate;

transferring the light emitting units on the first temporary substrate to a driving back plate;

preferably, the bonding layer is made of photosensitive adhesive material, the thickness of the bonding layer is 1 μm to 1mm, and the bonding layer is laid on the first temporary substrate.

10. The method according to claim 9, wherein,

the step of transferring the light emitting unit on the first temporary substrate to a driving back plate includes:

providing at least two first temporary substrates, wherein the light emitting colors of the light emitting units on different first temporary substrates are different;

transferring the light emitting units of each first temporary substrate to a second temporary substrate;

transferring the light emitting units on the second temporary substrate to the driving back plate; and/or the number of the groups of groups,

the step of transferring the light emitting unit on the first temporary substrate to a driving back plate includes, before:

forming a plurality of limit structures on the driving backboard, wherein limit grooves are formed between adjacent limit structures;

transferring the light-emitting unit into the limiting groove to limit the position of the light-emitting unit on the driving backboard;

preferably, the material of the limiting structure is photoresist, the thickness of the limiting structure is 0.5 μm to 50 μm, and the limiting structure is in a grid shape.