Preparation method of display panel, display panel and display module

Abstract

The invention provides a preparation method of a display panel, the display panel and a display module, and belongs to the technical field of photoelectron manufacturing. The preparation method comprises the steps that a chip carrier plate is bound to a driving circuit board, the chip carrier plate comprises a substrate and a plurality of pixel chips, the surface of the substrate comprises a light-emitting area and a handle area surrounding the light-emitting area, the pixel chips are located in the light-emitting area, orthographic projections of the light-emitting area on the board surface of the driving circuit board are all located on the board surface of the driving circuit board, and the handle area surrounds the light-emitting area; at least part of the orthographic projection of the handle area on the board surface of the driving circuit board is located outside the driving circuit board; forming a packaging layer between the substrate and the driving circuit board, and enabling the packaging layer to wrap each pixel chip; laser irradiates the chip carrier plate and applies external force to the handle area, so that the substrate is separated from the pixel chip and the packaging layer. According to the invention, the stripping difficulty of the substrate and the pixel chip can be reduced, and the preparation efficiency of the display panel can be improved.

Description

Technical Field

[0001] The present disclosure relates to the field of optoelectronic manufacturing technology, and in particular to a method for manufacturing a display panel, a display panel, and a display module. Background Art

[0002] Micro LED displays are display panels formed by thermally bonding ultra-small vertical micro LED chips to a specific driver circuit board. These panels can achieve resolutions exceeding 2.5K and brightness exceeding hundreds of thousands or even millions of nits in a display area less than 1 inch.

[0003] In the related art, when manufacturing a display panel, a pixel chip with a substrate is first thermally bonded directly to a driver circuit board, securing the pixel chip's electrodes to the driver circuit board's pads. Typically, bonding wires are installed in areas of the driver circuit board outside the area where the pixel chip is bonded. These wires connect to the pads, facilitating power flow to the driver circuit board via the bonding wires. To ensure high current supply and achieve high-power display, bonding wires are also installed in the area surrounding the pixel chip on the driver circuit board.

[0004] After the pixel chip is bonded to the driver circuit board, laser stripping is required to remove the substrate from the pixel chip. However, the bonding wires of the driver circuit board cannot be irradiated by the laser, otherwise they are very likely to short-circuit or break due to laser ablation. Therefore, during the substrate stripping process, the area of the substrate irradiated by the laser is usually reduced to avoid irradiating the edge of the substrate, which would allow the laser to irradiate the bonding wires. This will result in some pixel chips not being irradiated by the laser, making it difficult for the pixel chip to be naturally separated from the substrate, affecting the production efficiency of the display panel. Summary of the Invention

[0005] The embodiments of the present disclosure provide a method for manufacturing a display panel, a display panel, and a display module, which can reduce the difficulty of peeling the substrate and the pixel chip and improve the manufacturing efficiency of the display panel. The technical solution is as follows:

[0006] An embodiment of the present disclosure provides a method for preparing a display panel, the method comprising: binding a chip carrier to a driving circuit board, the chip carrier comprising a substrate and a plurality of pixel chips, the surface of the substrate comprising a light-emitting area and a handle area surrounding the light-emitting area, the pixel chips being located in the light-emitting area, the orthographic projections of the light-emitting areas on the board surface of the driving circuit board being all located on the board surface of the driving circuit board, and at least a portion of the orthographic projections of the handle areas on the board surface of the driving circuit board being located outside the driving circuit board; forming an encapsulation layer between the substrate and the driving circuit board so that the encapsulation layer wraps each of the pixel chips; irradiating the chip carrier with a laser and applying an external force to the handle area so that the substrate is separated from the pixel chips and the encapsulation layer.

[0007] In another implementation of the embodiment of the present disclosure, before binding the chip carrier to the driver circuit board, the process further includes: immersing the driver circuit board in a release agent to form a release layer on the board surface of the driver circuit board.

[0008] In another implementation of the embodiment of the present disclosure, soaking the driver circuit board in the release agent includes: soaking the driver circuit board in the release agent for 5 to 10 minutes; baking the driver circuit board for 20 to 30 minutes, and controlling the baking temperature to 80°C to 100°C.

[0009] In another implementation of the embodiment of the present disclosure, binding the chip carrier to the driving circuit board includes: forming a first metal layer on the electrode of the pixel chip and forming a second metal layer on the pad of the driving circuit board; bonding the electrode of the pixel chip to the pad of the driving circuit board so that the first metal layer and the second metal layer form an alloy layer.

[0010] In another implementation of the embodiment of the present disclosure, one of the first metal layer and the second metal layer is an Au layer, and the other of the first metal layer and the second metal layer is a Sn layer or an In layer; when the other of the first metal layer and the second metal layer is a Sn layer, the bonding temperature is controlled to be 260°C to 320°C, and lasts for 3 to 8 minutes; when the other of the first metal layer and the second metal layer is an In layer, the bonding temperature is controlled to be 180°C to 220°C, and lasts for 3 to 8 minutes.

[0011] In another implementation of the embodiment of the present disclosure, forming a packaging layer between the substrate and the driving circuit board includes: placing the driving circuit board and the chip carrier in a vacuum environment, and dripping packaging glue around the chip carrier on the board surface of the driving circuit board so that the packaging glue fills the gaps between each of the pixel chips.

[0012] In another implementation of the embodiment of the present disclosure, laser irradiating the chip carrier includes: laser irradiating the surface of the substrate to form a laser irradiation area on the surface of the substrate, the laser irradiation area is located in the light-emitting area, and the shortest distance from the peripheral edge of the laser irradiation area to the peripheral edge of the light-emitting area is 20μm to 30μm.

[0013] In another implementation of the embodiment of the present disclosure, after applying external force to the handle area to separate the substrate from the pixel chip and the packaging layer, it also includes: using soft tweezers to remove the packaging glue between the handle area and the driving circuit board to expose the welding wires of the driving circuit board located below the handle area.

[0014] An embodiment of the present disclosure provides a display panel, which is prepared using the preparation method described above. The display panel includes: a pixel chip, a driving circuit board and an encapsulation layer. The driving circuit board is provided with a soldering pad and a soldering wire. The soldering wire is arranged around the soldering pad on the driving circuit board. The pixel chip is located on the driving circuit board, and the electrode of the pixel chip is connected to the soldering pad. The encapsulation layer is located on the surface of the driving circuit board, the encapsulation layer includes the pixel chip, and the soldering wire is exposed.

[0015] An embodiment of the present disclosure provides a display panel, wherein the display module includes the display panel and the circuit control board as described above, wherein the display panel is located on the circuit control board; the circuit control board is provided with wiring electrodes on its surface, and the wiring electrodes are connected to the welding wires of the display panel through routing.

[0016] The beneficial effects of the technical solutions provided by the embodiments of the present disclosure include at least:

[0017] The method for preparing a display panel provided by an embodiment of the present disclosure first binds a chip carrier to a driver circuit board, wherein at least part of the orthographic projection of the handle area of the chip carrier substrate on the board surface of the driver circuit board is located outside the driver circuit board. That is, in a direction parallel to the driver circuit board, part of the handle area protrudes from the driver circuit board. Then, an encapsulation layer is formed between the substrate and the driver circuit board; finally, a laser is used to irradiate the chip carrier to decompose the epitaxial material between the substrate and the pixel chip, and the encapsulation layer between the substrate and the driver circuit board. In this way, by applying external force to the part of the handle area protruding from the driver circuit board, the substrate can be more easily peeled off from the pixel chip and the encapsulation layer.

[0018] Compared with the related art, the embodiment of the present disclosure extends the length of the substrate of the chip carrier so that the handle area on the substrate can protrude from the driving circuit board in a direction parallel to the driving circuit board. This makes it easier for technicians to apply external force to the substrate, thereby making it easier to peel the substrate off the driving circuit board, thereby improving the production efficiency of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, 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 disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 is a flow chart of a method for manufacturing a display panel provided by an embodiment of the present disclosure;

[0021] Figure 2 is a diagram showing a state of preparation of a display panel provided by an embodiment of the present disclosure;

[0022] Figure 3 is a flow chart of another method for manufacturing a display panel provided by an embodiment of the present disclosure;

[0023] Figure 4 is a diagram showing a state of preparation of a display panel provided by an embodiment of the present disclosure;

[0024] Figure 5 is a diagram showing a state of preparation of a display panel provided by an embodiment of the present disclosure;

[0025] Figure 6 is a diagram showing a state of preparation of a display panel provided by an embodiment of the present disclosure;

[0026] Figure 7 is a diagram showing a state of preparation of a display panel provided by an embodiment of the present disclosure;

[0027] Figure 8 1 is a schematic structural diagram of a display module provided by an embodiment of the present disclosure;

[0028] Figure 9 FIG. 1 is a structural diagram of another display module provided in an embodiment of the present disclosure.

[0029] The descriptions of the marks in the figure are as follows:

[0030] 10. Chip carrier; 11. Substrate; 111. Light-emitting area; 112. Handle area; 12. Pixel chip;

[0031] 20. Driver circuit board; 21. Solder pad; 22. Solder wire; 221. Top surface; 222. Side wall;

[0032] 30. Encapsulation layer;

[0033] 40. Circuit control board; 41. Wiring electrodes; 42. Wiring. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0035] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by a person of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," "third," and similar words used in the patent specification and claims of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish between different components. Similarly, terms such as "a" or "an" do not indicate a quantitative limitation, but rather indicate the presence of at least one. Terms such as "include" or "comprise" mean that the elements or objects preceding "include" or "comprises" encompass the elements or objects listed after "include" or "comprises," and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," "right," "top," and "bottom" are used only to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0036] Figure 1 FIG. 1 is a flow chart of a method for manufacturing a display panel according to an embodiment of the present disclosure. Figure 1 As shown, the preparation method comprises:

[0037] Step 101: Bind the chip carrier to the driver circuit board.

[0038] Figure 2 FIG. 1 is a diagram showing the preparation state of a display panel provided by an embodiment of the present disclosure. Figure 2 As shown, the chip carrier 10 includes a substrate 11 and a plurality of pixel chips 12. The surface of the substrate 11 includes a light-emitting area 111 and a handle area 112 surrounding the light-emitting area 111. The pixel chips 12 are located in the light-emitting area 111. The orthographic projections of the light-emitting area 111 on the surface of the driving circuit board 20 are all located on the surface of the driving circuit board 20. At least part of the orthographic projection of the handle area 112 on the surface of the driving circuit board 20 is located outside the driving circuit board 20.

[0039] Step 102 : forming a packaging layer 30 between the substrate 11 and the driving circuit board 20 , so that the packaging layer 30 wraps each pixel chip 12 .

[0040] Step 103 : Laser irradiates the chip carrier 10 and applies external force to the handle area 112 to separate the substrate 11 from the pixel chip 12 and the packaging layer 30 .

[0041] The method for manufacturing a display panel provided by an embodiment of the present disclosure first binds a chip carrier 10 to a driver circuit board 20, wherein at least part of the orthographic projection of the handle area 112 of the substrate 11 of the chip carrier 10 on the surface of the driver circuit board 20 is located outside the driver circuit board 20. That is, in a direction parallel to the driver circuit board 20, a portion of the handle area 112 protrudes from the driver circuit board 20. Then, an encapsulation layer 30 is formed between the substrate 11 and the driver circuit board 20; finally, a laser is used to irradiate the chip carrier 10 to decompose the epitaxial material between the substrate 11 and the pixel chip 12, and the encapsulation layer 30 between the substrate 11 and the driver circuit board 20. In this way, by applying external force to the portion of the handle area 112 protruding from the driver circuit board 20, the substrate 11 can be more easily peeled off from the pixel chip 12 and the encapsulation layer 30.

[0042] Compared with the related art, the embodiment of the present disclosure extends the length of the substrate 11 of the chip carrier 10 so that the handle area 112 on the substrate 11 can protrude from the driving circuit board 20 in a direction parallel to the driving circuit board 20. This makes it convenient for technicians to apply external force to the substrate 11, thereby making it easier to peel the substrate 11 off the driving circuit board 20, thereby improving the production efficiency of the display panel.

[0043] Figure 3 FIG. 1 is a flow chart of another method for manufacturing a display panel provided by an embodiment of the present disclosure. Figure 3 As shown, the preparation method comprises:

[0044] Step 201 : Immerse the driving circuit board 20 in a release agent to form a release layer on the board surface of the driving circuit board 20 .

[0045] Specifically, the process may include: soaking the driving circuit board 20 in a release agent for 5 to 10 minutes; and baking the driving circuit board for 20 to 30 minutes, with the baking temperature being controlled at 80° C. to 100° C.

[0046] For example, the release agent can be a water-based release agent or a fluorine-based release agent. For example, the driver circuit board 20 can be immersed in a fluorine-based release agent. During the immersion process, the driver circuit board 20 can be turned over to ensure that the driver circuit board 20 is fully in contact with the release agent.

[0047] In the embodiment of the present disclosure, controlling the soaking time of the driver circuit board 20 within the above range can ensure that the release agent fully penetrates the micropores on the board surface of the driver circuit board 20 to form a continuous and uniform coating, avoid missing coating or accumulation, and reduce the risk of demolding failure.

[0048] Exemplarily, the time for soaking the driving circuit board 20 may be 7 minutes.

[0049] In the embodiment of the present disclosure, by baking the driving circuit board 20 , micropores in the coating layer on the driving circuit board 20 are eliminated, the surface hydrophobicity is improved, and the risk of liquid material penetrating into the coating layer is reduced.

[0050] For example, the driving circuit board is baked for 25 minutes, and the baking temperature is controlled to be 90° C.

[0051] In the disclosed embodiment, the driving circuit board 20 includes a board body and a plurality of pads 21 on the board body. The pads 21 are arranged corresponding to the electrodes on the pixel chip 12 so that the pixel chip 12 can be bonded to the driving circuit board 20 .

[0052] like Figure 4 As shown, bonding wires 22 are arranged around a plurality of bonding pads 21 on the driver circuit board 20, and the bonding wires 22 are electrically connected to the bonding pads 21. The bonding wires 22 surround the bonding pads 21 in a rectangular frame shape, so that more bonding wires 22 can inject current into the bonding pads 21, thereby ensuring that a large current is supplied to the pixel chip 12 to achieve high-power display.

[0053] Illustratively, after the driving circuit board 20 is soaked in the release agent, a thin layer of release agent is retained on the surface of the driving circuit board 20 , the pads 21 and the welding wires 22 , so that residual glue deposited on the welding wires 22 can be subsequently cleaned.

[0054] like Figure 2 As shown, since there is an overlapping area between the handle area 112 and the driver circuit board 20, and some of the welding wires 22 on the driver circuit board 20 are located in the overlapping area, when the packaging glue is formed on the driver circuit board 20, some of the welding wires 22 are covered by the packaging glue. The welding wires 22 need to be connected to an external power supply to transmit current. Therefore, after removing the substrate 11 from the handle area 112, the packaging glue remaining in the overlapping area also needs to be removed. If the packaging glue is removed by external force, it will easily cause damage to the welding wires 22 at that location. Therefore, the embodiment of the present disclosure treats the driver circuit board 20 with a release agent first, so that a thin layer of release agent is formed on the surface of the welding wires 22. In this way, when cleaning the residual glue, the residual glue is more likely to fall off from the thin layer of release agent, thereby avoiding the problem of external force removing the packaging glue, causing damage to the welding wires 22 at that location.

[0055] Step 202 : forming a first metal layer on the electrode of the pixel chip 12 , and forming a second metal layer on the pad 21 of the driving circuit board 20 .

[0056] Step 203 : bonding the electrodes of the pixel chip 12 to the pads 21 of the driving circuit board 20 , so that the first metal layer and the second metal layer form an alloy layer.

[0057] Optionally, one of the first metal layer and the second metal layer is an Au layer, and the other of the first metal layer and the second metal layer is a Sn layer or an In layer.

[0058] For example, when the other of the first metal layer and the second metal layer is a Sn layer, the bonding temperature is controlled to be 260° C. to 320° C. and the duration is 3 min to 8 min.

[0059] The Au layer and the Sn layer are bonded to form an AuSn alloy. The AuSn alloy has a high thermal conductivity and can effectively conduct the heat generated by the pixel chip 12, thereby reducing thermal resistance and preventing overheating failure.

[0060] In addition, the resistance of gold in the AuSn alloy is low, which can reduce the contact resistance of the alloy, ensure efficient current transmission, and reduce energy consumption and light efficiency loss.

[0061] During the bonding process, controlling the bonding temperature within this range allows the tin to melt and rapidly diffuse with the gold to form a stable eutectic phase, while avoiding the formation of brittle and unstable intermetallic compounds. The efficient completion of the eutectic reaction ensures a uniform and strong bond interface, and achieves a clean surface bond without the need for flux.

[0062] For example, when the other of the first metal layer and the second metal layer is an In layer, the bonding temperature is controlled to be 180° C. to 220° C. and the duration is 3 min to 8 min.

[0063] When bonding the Au layer to the In layer, since the melting point of indium is only 156°C, when forming a eutectic alloy with Au, the bonding temperature can be controlled within 180°C to 220°C. This feature allows for soldering without the need for high-temperature processes, significantly reducing the risk of damage to the pixel chip 12.

[0064] At the same time, the thermal conductivity of indium is higher than that of traditional tin. Combined with the thermal conductivity of gold, it can more efficiently conduct the heat generated by the pixel chip 12, reduce the junction temperature and improve the light efficiency.

[0065] Step 204 : placing the driving circuit board 20 and the chip carrier 10 in a vacuum environment, dripping packaging glue around the chip carrier 10 onto the board surface of the driving circuit board 20 so that the packaging glue fills the gaps between the pixel chips 12 .

[0066] like Figure 5 As shown, the method may include dripping epoxy resin or silicone glue around the chip carrier 10 on the driver circuit board 20. The glue will gradually flow into the gaps between adjacent pixel chips 12 by the capillary effect, and then be heated to cure the glue.

[0067] Optionally, heating and curing the encapsulation adhesive may specifically include: controlling the temperature to rise to above 50° C. and heating and curing the encapsulation adhesive; controlling the temperature to rise to above 150° C. and baking the encapsulation adhesive for 1 to 2 hours to obtain the encapsulation layer 30 .

[0068] Among them, first controlling the temperature to rise to above 50°C can accelerate the curing speed and achieve rapid curing of the encapsulation glue; then controlling the temperature to rise to above 150°C to bake the encapsulation glue so that the encapsulation glue can be completely cured.

[0069] In the embodiment of the present disclosure, the purpose of providing the packaging glue between the chip carrier 10 and the driving circuit board 20 is to protect the pixel chip 12 and prevent the pixel chip 12 from being damaged by the laser due to the lack of a protective film layer during the peeling process of the substrate 11.

[0070] Optionally, the light absorption rate of the encapsulant is greater than or equal to 0.8. Wrapping the pixel chip 12 with an encapsulant having a light absorption rate greater than or equal to 0.8 can block the side light emission of the pixel chip 12 and improve the front light emission effect of the light emitting device.

[0071] For example, the encapsulation layer 30 can be black, as black absorbs light more easily, thereby preventing more light from being emitted from the sides of the pixel chips 12. Furthermore, during the encapsulation process, the black encapsulation is easier to observe, helping technicians accurately determine whether the encapsulation is completely encapsulated by each pixel chip 12.

[0072] Step 205 : Laser irradiates the chip carrier 10 and applies external force to the handle area 112 to separate the substrate 11 from the pixel chip 12 and the packaging layer 30 .

[0073] like Figure 6 As shown, after applying external force from the handle area to peel the substrate and the pixel chip 12, the pixel chip 12 and the encapsulation layer 30 remain on the driving circuit board 20, and the encapsulation layer 30 also remains in the area opposite to the handle area 112 and the driving circuit board 20.

[0074] In the embodiment of the present disclosure, irradiating the chip carrier 10 with laser may include: irradiating the surface of the substrate 11 with laser to form a laser irradiation area on the surface of the substrate 11 .

[0075] The laser irradiation area is located within the light emitting area 111 , and the shortest distance from the peripheral edge of the laser irradiation area to the peripheral edge of the light emitting area 111 is 20 μm to 30 μm.

[0076] Exemplarily, the pixel chips 12 on the substrate 11 are arranged in a rectangular array, that is, the area on the substrate 11 that needs to be irradiated by the laser is rectangular in shape. Therefore, the shape of the laser irradiation area can also be set to be rectangular.

[0077] By appropriately reducing the area of the laser irradiation area so that the peripheral edge of the laser irradiation area maintains a certain distance from the peripheral edge of the light-emitting area 111, the laser can be prevented from irradiating the welding wires 22 around the chip carrier 10, thereby preventing the laser from burning the welding wires 22 and causing the welding wires 22 to short-circuit or break.

[0078] Step 206 : Use soft tweezers to remove the packaging glue between the handle area 112 and the driver circuit board 20 to expose the solder wires 22 of the driver circuit board 20 below the handle area 112 .

[0079] In the embodiment of the present disclosure, the driving circuit board 20 is treated with a release agent so that a thin layer of release agent is formed on the surface of the welding wire 22. Figure 6 、 7 As shown, when cleaning the encapsulation glue, the encapsulation glue covering the bonding wires 22 is more likely to fall off from the release agent layer. Therefore, the remaining encapsulation glue can be easily removed using soft tweezers, and the soft tweezers are less likely to damage the driver circuit board 20 and the pixel chip 12.

[0080] The embodiment of the present disclosure provides a display panel, which is prepared by the preparation method described above. Figure 7 As shown, the display panel includes: a pixel chip 12, a driving circuit board 20 and an encapsulation layer 30. The driving circuit board 20 is provided with a soldering pad 21 and a soldering wire 22. The soldering wire 22 is arranged around the soldering pad 21 on the driving circuit board 20. The pixel chip 12 is located on the driving circuit board 20, and the electrode of the pixel chip 12 is connected to the soldering pad 21. The encapsulation layer 30 is located on the surface of the driving circuit board 20. The encapsulation layer 30 includes the pixel chip 12, and the encapsulation layer 30 exposes the soldering wire 22 to facilitate the subsequent connection of the soldering wire 22 with the trace 42, so that the soldering wire 22 can be connected to an external power supply or electronic device.

[0081] Pixel chips 12 of different colors may be arranged on the driving circuit board 20 to achieve full-color display.

[0082] Optionally, the pixel chips 12 of different colors include a first pixel chip, a second pixel chip, and a third pixel chip, and the first pixel chip, the second pixel chip, and the third pixel chip all emit different colors.

[0083] In the embodiment of the present disclosure, the first pixel chip may be a pixel chip 12 that emits red light, the second pixel chip may be a pixel chip 12 that emits green light, and the third pixel chip may be a pixel chip 12 that emits blue light.

[0084] In the disclosed embodiment, each pixel chip 12 includes an epitaxial layer, a passivation layer, and electrodes. The epitaxial layer is located on the surface of the substrate 11 and includes a p-type layer, a light-emitting layer, and an n-type layer stacked in sequence. The n-type layer has a groove that exposes the p-type layer. The passivation layer is located on the surface of the n-type layer and within the groove, and the passivation layer has a through hole that exposes the n-type layer and the groove.

[0085] The surface of the passivation layer is provided with a first electrode and a second electrode, which are connected to the n-type layer and the p-type layer respectively through two through holes. The first electrode and the second electrode are both used to bond with the pad 21 on the driving circuit board 20.

[0086] The difference between the first pixel chip, the second pixel chip and the third pixel chip lies in the different luminescent colors of the epitaxial layers.

[0087] For the first pixel chip, the epitaxial layer is a red epitaxial layer. For the second pixel chip, the epitaxial layer is a green epitaxial layer. For the third pixel chip, the epitaxial layer is a blue epitaxial layer.

[0088] The red epitaxial layer includes a first p-type layer, a first light-emitting layer and a first n-type layer stacked in sequence.

[0089] In the red epitaxial layer, the first p-type layer includes a p-type AlInP layer.

[0090] The first light-emitting layer includes alternately grown AlGaInP quantum well layers and AlGaInP quantum barrier layers, wherein the Al content in the AlGaInP quantum well layers and the AlGaInP quantum barrier layers is different. The first light-emitting layer may include 3 to 8 periods of alternately stacked AlGaInP quantum well layers and AlGaInP quantum barrier layers.

[0091] The first n-type layer includes an n-type AlGaInP current spreading layer.

[0092] In the embodiment of the present disclosure, the green epitaxial layer includes a second p-type layer, a second light-emitting layer, and a second n-type layer stacked in sequence.

[0093] In the green epitaxial layer, the second p-type layer includes a p-type GaN layer.

[0094] The second light-emitting layer includes alternately grown InGaN quantum well layers and GaN quantum barrier layers. The second light-emitting layer may include 3 to 8 periods of alternately stacked InGaN quantum well layers and GaN quantum barrier layers.

[0095] The second n-type layer includes an n-type GaN layer.

[0096] In the embodiment of the present disclosure, the blue epitaxial layer includes a third p-type layer, a third light-emitting layer, and a third n-type layer stacked in sequence.

[0097] In the blue epitaxial layer, the third p-type layer includes a p-type GaN layer.

[0098] The third light-emitting layer may include alternately grown InGaN quantum well layers and GaN quantum barrier layers. The third light-emitting layer may include 3 to 8 periods of alternately stacked InGaN quantum well layers and GaN quantum barrier layers.

[0099] The third n-type layer includes an n-type GaN layer.

[0100] Optionally, the thickness of the pixel chip 12 is 2 μm to 10 μm.

[0101] Exemplarily, the thickness of the red epitaxial layer is 5 μm, the thickness of the green epitaxial layer is 8 μm, and the thickness of the blue epitaxial layer is 6 μm.

[0102] Figure 8 FIG. 1 is a schematic diagram of a structure of a display module provided by an embodiment of the present disclosure. Figure 8 As shown, the display module includes the display panel and the circuit control board 40 as described above, and the display panel is located on the circuit control board 40.

[0103] Exemplarily, a wiring electrode 41 is provided on the board surface of the circuit control board 40 , and the wiring electrode 41 is connected to the bonding wire 22 of the display panel via a trace 42 .

[0104] For example, as shown in the figure, in the display panel, the driver circuit board 20 is further provided with bonding wires 22 surrounding the pixel chip 12. The bonding wires 22 of the driver circuit board 20 are connected to the wiring electrodes 41 on the circuit control board 40 via traces 42, so that an external power source can transmit current to the bonding wires 22 through the wiring electrodes 41, thereby controlling the pixel chip 12 to be energized.

[0105] Alternatively, as Figure 9 As shown, one end of the trace 42 may be connected to the wiring electrode 41 , and the other end of the trace 42 may be connected to the side wall of the bonding wire 22 .

[0106] In the embodiment of the present disclosure, the surface of the bonding wire 22 includes a top surface 221 away from the circuit control board 40 , and a side wall 222 connected between the top surface 221 and the circuit control board 40 .

[0107] After the chip carrier 10 is bonded to the driver circuit board 20, a portion of the handle region 112 of the substrate 11 of the chip carrier 10 overlaps with the top surface of the bonding wire 22. Therefore, when the encapsulation layer 30 is subsequently prepared, the top surface 221 of the bonding wire 22 is easily adhered to by the encapsulation layer 30. Furthermore, if the encapsulation layer 30 remains on the top surface 221 of the bonding wire 22 after the handle region 112 is removed and is not completely removed, making it difficult for the trace 42 to be electrically connected to the bonding wire 22, one end of the trace 42 can be connected to the exposed sidewall 222 of the bonding wire 22, thereby ensuring a path between the wiring electrode 41 and the bonding wire 22.

[0108] The above does not limit the present disclosure in any form. Although the present disclosure has been disclosed as above through the embodiments, it is not intended to limit the present disclosure. Any technician familiar with the profession can make slight changes or modifications to equivalent embodiments with equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present disclosure. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present disclosure without departing from the content of the technical solution of the present disclosure are still within the scope of the technical solution of the present disclosure.

Claims

1. A method for preparing a display panel, characterized in that: The preparation method comprises: Binding a chip carrier (10) to a driving circuit board (20), wherein the chip carrier (10) comprises a substrate (11) and a plurality of pixel chips (12), wherein a surface of the substrate (11) comprises a light-emitting area (111) and a handle area (112) surrounding the light-emitting area (111), wherein the pixel chips (12) are located in the light-emitting area (111), and the orthographic projections of the light-emitting area (111) on the surface of the driving circuit board (20) are all located on the surface of the driving circuit board (20), and at least a portion of the orthographic projections of the handle area (112) on the surface of the driving circuit board (20) is located outside the driving circuit board (20); forming a packaging layer (30) between the substrate (11) and the driving circuit board (20), so that the packaging layer (30) wraps each pixel chip (12); Laser irradiates the chip carrier (10), and external force is applied to the handle area (112), so that the substrate (11) is separated from the pixel chip (12) and the packaging layer (30).

2. The preparation method according to claim 1, characterized in that Before the chip carrier (10) is bound to the driver circuit board (20), the method further includes: The driving circuit board (20) is immersed in a release agent to form a release layer on the board surface of the driving circuit board (20).

3. The preparation method according to claim 2, characterized in that Soaking the driving circuit board (20) in a release agent comprises: Soaking the driving circuit board (20) in a release agent for 5 to 10 minutes; The driving circuit board (20) is baked for 20 to 30 minutes, and the baking temperature is controlled to be 80° C. to 100° C.

4. The preparation method according to any one of claims 1 to 3, characterized in that Binding the chip carrier (10) to the driver circuit board (20) includes: forming a first metal layer on the electrode of the pixel chip (12), and forming a second metal layer on the pad (21) of the driving circuit board (20); The electrodes of the pixel chip (12) are bonded to the pads (21) of the driving circuit board (20), so that the first metal layer and the second metal layer form an alloy layer.

5. The preparation method according to claim 4, characterized in that One of the first metal layer and the second metal layer is an Au layer, and the other of the first metal layer and the second metal layer is a Sn layer or an In layer; When the other of the first metal layer and the second metal layer is a Sn layer, the bonding temperature is controlled to be 260° C. to 320° C. for 3 to 8 minutes; When the other of the first metal layer and the second metal layer is an In layer, the bonding temperature is controlled to be 180° C. to 220° C. and the duration is 3 minutes to 8 minutes.

6. The preparation method according to any one of claims 1 to 3, characterized in that Forming a packaging layer (30) between the substrate (11) and the driving circuit board (20) includes: The driving circuit board (20) and the chip carrier board (10) are placed in a vacuum environment, and packaging glue surrounding the chip carrier board (10) is dripped onto the board surface of the driving circuit board (20) so that the packaging glue fills the gaps between the pixel chips (12).

7. The preparation method according to any one of claims 1 to 3, characterized in that Laser irradiation of the chip carrier (10) comprises: Laser irradiates the surface of the substrate (11) to form a laser irradiation area on the surface of the substrate (11), wherein the laser irradiation area is located within the light-emitting area (111), and the shortest distance from the peripheral edge of the laser irradiation area to the peripheral edge of the light-emitting area (111) is 20 μm to 30 μm.

8. The preparation method according to any one of claims 1 to 3, characterized in that After applying an external force to the handle area (112) so as to separate the substrate (11) from the pixel chip (12) and the encapsulation layer (30), the method further comprises: Soft tweezers are used to remove the packaging glue between the handle area (112) and the driving circuit board (20) to expose the welding wire (22) of the driving circuit board (20) located below the handle area (112).

9. A display panel, characterized in that: The display panel is prepared by the preparation method according to any one of claims 1 to 8, and the display panel comprises: a pixel chip (12), a driving circuit board (20) and an encapsulation layer (30), wherein the driving circuit board (20) is provided with a soldering pad (21) and a soldering wire (22), and the soldering wire (22) is arranged on the driving circuit board (20) around the soldering pad (21), the pixel chip (12) is located on the driving circuit board (20), and the electrode of the pixel chip (12) is connected to the soldering pad (21), and the encapsulation layer (30) is located on the surface of the driving circuit board (20), the encapsulation layer (30) includes the pixel chip (12), and the soldering wire (22) is exposed.

10. A display module, characterized in that: The display module comprises the display panel according to claim 9 and a circuit control board (40), wherein the display panel is located on the circuit control board (40); The circuit control board (40) is provided with a wiring electrode (41) on its surface, and the wiring electrode (41) is connected to the welding wire (22) of the display panel via a wiring (42).

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