Light-emitting device, packaging method of light-emitting device and display panel

Abstract

The invention provides a light-emitting device, a packaging method of the light-emitting device and a display panel, and belongs to the technical field of photoelectron manufacturing. The packaging method comprises the following steps: transferring a plurality of pixel chips to the surface of a temporary substrate; all the pixel chips are bound to a circuit substrate, and the sides, away from the temporary substrate, of the pixel chips are made to be connected with the circuit substrate; filling packaging glue between the circuit substrate and the temporary substrate to form a packaging glue layer wrapping the pixel chips; and removing the temporary substrate to expose the surface, far away from the circuit substrate, of the pixel chip. According to the invention, the problem that the shielding areas of the packaging adhesive layer to different pixel chips are inconsistent can be improved, and the display effect of the light-emitting device is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of optoelectronic manufacturing technologies, and particularly to a light-emitting device, a packaging method for a light-emitting device, and a display panel. Background Art

[0002] In the emerging display field, Mini / Micro LEDs are continuously expanding the application boundaries of display screens. For a light-emitting device of MIP (MicroLED in package), by separately packaging a large-area integral display panel, an organic combination of Micro LEDs and discrete devices is achieved.

[0003] In related technologies, a light-emitting device of MIP includes a plurality of pixel chips and a circuit board. The plurality of pixel chips are bonded to solder joints on the circuit board, and an encapsulation glue layer is further provided on the circuit board to fill the gaps between the pixel chips. The thickness of the filled encapsulation glue layer is usually greater than the height of the pixel chips. Therefore, after forming the encapsulation glue layer, an etching method is required to expose the pixel chips to avoid affecting the light emission or conductivity of the pixel chips.

[0004] When manufacturing a light-emitting device, usually, pixel chips of different light-emitting devices are bonded to the same circuit board. However, the pitch between pixel chips within the same light-emitting device is small, while the pitch between pixel chips of different light-emitting devices is large. Thus, when etching the encapsulation glue layer, in the area where the gap between pixel chips is small, due to factors such as narrow channels where less etching gas enters or it is difficult for gas to be replaced and discharged, the etching speed is slow, while in the area where the gap between pixel chips is large, the etching speed is fast. Therefore, there will be a situation where the thickness of the encapsulation glue layer within the gap between pixel chips in the same light-emitting device is greater than the thickness of the encapsulation glue layer within the gap between adjacent light-emitting devices. This thickness difference will cause the shielding area of the encapsulation glue layer for different pixel chips to be inconsistent, affecting the packaging effect and also causing monochromatic viewing angle differences, seriously affecting the display effect. Summary of the Invention

[0005] Embodiments of the present disclosure provide a light-emitting device, a packaging method for a light-emitting device, and a display panel, which can improve the problem of inconsistent shielding areas of the encapsulation glue layer for different pixel chips and enhance the display effect of the light-emitting device. The technical solutions are as follows:

[0006] Embodiments of the present disclosure provide a packaging method for a light-emitting device. The packaging method includes: transferring a plurality of pixel chips onto the surface of a temporary substrate; bonding each of the pixel chips to a circuit board such that the side of the pixel chip away from the temporary substrate is connected to the circuit board; filling an encapsulation glue between the circuit board and the temporary substrate to form an encapsulation glue layer that wraps each of the pixel chips; and removing the temporary substrate to expose the surface of the pixel chip away from the circuit board.

[0007] In another implementation manner of the embodiment of the present disclosure, the surface of the temporary substrate has glue injection holes penetrating through the temporary substrate, and the glue injection holes are arranged at intervals from the pixel chips; filling encapsulation glue between the circuit substrate and the temporary substrate to form an encapsulation glue layer wrapping each of the pixel chips includes: injecting encapsulation glue into the gap between the circuit substrate and the temporary substrate through the glue injection holes; after the encapsulation glue fills the gaps between the pixel chips, curing the encapsulation glue to obtain the encapsulation glue layer.

[0008] In another implementation manner of the embodiment of the present disclosure, the surface of the temporary substrate has one glue injection hole, and the glue injection hole is located at the geometric center of the temporary substrate; alternatively, the surface of the temporary substrate has a plurality of glue injection holes, and the plurality of glue injection holes are circumferentially arranged at intervals with the geometric center of the temporary substrate as the center; alternatively, the surface of the temporary substrate has a plurality of glue injection holes, and the plurality of glue injection holes are arranged in an array.

[0009] In another implementation manner of the embodiment of the present disclosure, curing the encapsulation glue to obtain the encapsulation glue layer includes: controlling the temperature to rise above 50°C and heating and curing the encapsulation glue; controlling the temperature to rise above 150°C and baking the encapsulation glue for 1 h to 2 h to obtain the encapsulation glue layer; or irradiating the encapsulation glue with ultraviolet light for 1 min to 10 min to obtain the encapsulation glue layer.

[0010] In another implementation manner of the embodiment of the present disclosure, the diameter of the glue injection hole is less than or equal to the gap between adjacent pixel chips.

[0011] In another implementation manner of the embodiment of the present disclosure, filling encapsulation glue between the circuit substrate and the temporary substrate to form an encapsulation glue layer wrapping each of the pixel chips includes: placing the circuit substrate bound with the pixel chips in a glue injection container, and the glue injection container is filled with liquid encapsulation glue, and the liquid level height of the encapsulation glue is greater than the sum of the thicknesses of the pixel chips and the circuit substrate.

[0012] In another implementation manner of the embodiment of the present disclosure, the surface of the glue injection container has air extraction holes communicating with the inner cavity of the glue injection container; after placing the circuit substrate bound with the pixel chips in the glue injection container, it further includes: evacuating the inner cavity of the glue injection container through the air extraction holes to reduce the air pressure in the glue injection container, so that the encapsulation glue fills the gaps between the pixel chips.

[0013] In another implementation of the embodiments of the present disclosure, removing the temporary substrate to expose the surface of the pixel chip away from the circuit substrate includes: laser peeling the temporary substrate, and cleaning the glue layer on the surface of the pixel chip with a cleaning agent to expose the pixel chip.

[0014] The embodiments of the present disclosure provide a light-emitting device, which includes: a circuit substrate, a plurality of pixel chips, and a packaging glue layer; the plurality of pixel chips are all located on the surface of the circuit substrate, the packaging glue layer is located on the surface of the circuit substrate and wraps each pixel chip, and the surface of the packaging glue layer away from the circuit substrate is flush with the surface of the pixel chip away from the circuit substrate.

[0015] The embodiments of the present disclosure provide a display panel, which includes a plurality of light-emitting devices, a driving integrated circuit, and a circuit board as described above, and the plurality of light-emitting devices and the driving integrated circuit are all located on the circuit board.

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

[0017] When encapsulating the light-emitting device by the encapsulation method provided by the embodiments of the present disclosure, first transfer a plurality of pixel chips onto the surface of the temporary substrate; then, bond one side of each pixel chip away from the temporary substrate to the circuit substrate; next, fill the encapsulation glue between the circuit substrate and the temporary substrate to form an encapsulation glue layer that wraps each pixel chip; finally, remove the temporary substrate to expose the surface of the pixel chip away from the circuit substrate. This method of filling the encapsulation glue between the circuit substrate and the temporary substrate limits the upper limit of the thickness of the encapsulation glue layer by using the area formed by sandwiching the temporary substrate and the circuit substrate, so that the thickness of the encapsulation glue layer does not exceed the thickness of the pixel chip. In the related art, the thickness of the encapsulation glue layer formed by the spin coating method exceeds the thickness of the pixel chip, so it is necessary to etch the encapsulation glue layer to expose the pixel chip. Therefore, the encapsulation method provided by the embodiments of the present disclosure does not require an etching process, and only needs to peel off the temporary substrate to expose the pixel chip, and the surfaces of all regions of the encapsulation glue layer are flush with the top surface of the pixel chip. This fundamentally avoids the problem that the thickness of the encapsulation glue layer in the gap between pixel chips in the same light-emitting device is greater than the thickness of the encapsulation glue layer in the gap between adjacent light-emitting devices caused by the etching process, improves the problem that the shielding area of the encapsulation glue layer for different pixel chips is inconsistent, and enhances the encapsulation effect of the encapsulation glue layer and the display effect of the light-emitting device. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0019] Figure 1 It is a flowchart of a method for packaging a light-emitting device provided by an embodiment of the present disclosure;

[0020] Figure 2 It is a flowchart of another method for packaging a light-emitting device provided by an embodiment of the present disclosure;

[0021] Figure 3 It is a schematic diagram of the packaging of a light-emitting device provided by an embodiment of the present disclosure;

[0022] Figure 4 It is a top view of a temporary substrate provided by an embodiment of the present disclosure;

[0023] Figure 5 It is a schematic diagram of the packaging of a light-emitting device provided by an embodiment of the present disclosure;

[0024] Figure 6 It is a top view of a light-emitting device provided by an embodiment of the present disclosure;

[0025] Figure 7 It is a top view of a light-emitting device provided by an embodiment of the present disclosure.

[0026] The descriptions of each mark in the figure are as follows:

[0027] 11. Temporary substrate; 110. Glue injection hole; 12. Circuit board;

[0028] 20. Pixel chip; 21. First pixel chip; 22. Second pixel chip; 23. Third pixel chip;

[0029] 31. First pad; 32. Second pad; 33. Third pad; 34. Fourth pad;

[0030] 41. First electrode; 42. Second electrode;

[0031] 50. Encapsulation glue layer;

[0032] 60. Glue injection container; 61. Air extraction hole. Detailed implementation manners

[0033] To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following will further describe the embodiments of the present disclosure in detail with reference to the accompanying drawings.

[0034] Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which this disclosure pertains. The terms "first", "second", "third" and similar terms used in the specification and claims of this patent application of the disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a quantity limitation, but rather indicate the presence of at least one. Terms such as "comprising" or "including" mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, and do not exclude other elements or items. Terms such as "connected" or "coupled" 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", "bottom" are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0035] Figure 1 is a flowchart of a packaging method for a light-emitting device provided by an embodiment of the disclosure. As Figure 1 shown, the packaging method includes:

[0036] Step 101: Transfer a plurality of pixel chips onto the surface of a temporary substrate.

[0037] Step 102: Bond each pixel chip to a circuit substrate, such that the side of the pixel chip away from the temporary substrate is connected to the circuit substrate.

[0038] Step 103: Fill a packaging adhesive between the circuit substrate and the temporary substrate to form a packaging adhesive layer that wraps each pixel chip.

[0039] Step 104: Remove the temporary substrate to expose the surface of the pixel chip away from the circuit substrate.

[0040] When encapsulating a light-emitting device using the encapsulation method provided in an embodiment of the present disclosure, first, a plurality of pixel chips are transferred onto the surface of a temporary substrate; then, one side of each pixel chip away from the temporary substrate is bonded to a circuit substrate; next, an encapsulation adhesive is filled between the circuit substrate and the temporary substrate to form an encapsulation adhesive layer that wraps each pixel chip; finally, the temporary substrate is removed to expose the surface of the pixel chip away from the circuit substrate. This way of filling the encapsulation adhesive between the circuit substrate and the temporary substrate uses the area formed by sandwiching the temporary substrate and the circuit substrate to limit the upper limit of the thickness of the encapsulation adhesive layer, so that the thickness of the encapsulation adhesive layer does not exceed the thickness of the pixel chip. In the related art, the thickness of the encapsulation adhesive layer formed by the spin coating method exceeds the thickness of the pixel chip, so an etching method is also required to etch the encapsulation adhesive layer to expose the pixel chip. Therefore, the encapsulation method provided in the embodiment of the present disclosure does not require an etching process. Only by peeling off the temporary substrate can the pixel chip be exposed, and the surfaces of all regions of the encapsulation adhesive layer are flush with the top surface of the pixel chip. In this way, the problem that the thickness of the encapsulation adhesive layer in the gap between pixel chips in the same light-emitting device is greater than the thickness of the encapsulation adhesive layer in the gap between adjacent light-emitting devices caused by the etching process is fundamentally avoided, the problem that the shielding area of the encapsulation adhesive layer for different pixel chips is inconsistent is improved, and the encapsulation effect of the encapsulation adhesive layer and the display effect of the light-emitting device are enhanced.

[0041] Figure 2 is a flowchart of another encapsulation method for a light-emitting device provided in an embodiment of the present disclosure. As Figure 2 shown, this encapsulation method includes:

[0042] Step 201: Transfer a plurality of pixel chips onto the surface of a temporary substrate.

[0043] Specifically, it may include: As Figure 3 shown, a plurality of pixel chips 20 are arranged on a temporary substrate 11 by a mass transfer method.

[0044] Exemplarily, the temporary substrate 11 may be a sapphire substrate or a glass substrate.

[0045] Optionally, as Figure 3 shown, the plurality of pixel chips 20 include a first pixel chip 21, a second pixel chip 22, and a third pixel chip 23, and the light-emitting colors of the first pixel chip 21, the second pixel chip 22, and the third pixel chip 23 are all different.

[0046] In an embodiment of the present disclosure, the first pixel chip 21 may be a pixel chip that emits red light, the second pixel chip 22 may be a pixel chip that emits green light, and the third pixel chip 23 may be a pixel chip that emits blue light.

[0047] In the embodiments of the present disclosure, each pixel chip includes an epitaxial layer, a passivation layer, and an electrode. The epitaxial layer is located on the surface of the substrate. The epitaxial layer includes a p-type layer, a light-emitting layer, and an n-type layer stacked in sequence. The n-type layer has a groove exposing the p-type layer. The passivation layer is located on the surface of the n-type layer and in the groove, and the passivation layer has a through hole exposing the n-type layer and the groove.

[0048] Wherein, a first electrode 41 and a second electrode 42 are provided on the surface of the passivation layer. The first electrode 41 and the second electrode 42 are respectively connected to the n-type layer and the p-type layer through two through holes.

[0049] In the embodiments of the present disclosure, a plurality of pixel chips include a first pixel chip 21 that emits red light, a second pixel chip 22 that emits green light, and a third pixel chip 23 that emits blue light.

[0050] The difference among the first pixel chip 21, the second pixel chip 22, and the third pixel chip 23 lies in the different light-emitting colors of the epitaxial layers.

[0051] For the first pixel chip 21, the epitaxial layer is a red-light epitaxial layer. For the second pixel chip 22, the epitaxial layer is a green-light epitaxial layer. For the third pixel chip 23, the epitaxial layer is a blue-light epitaxial layer.

[0052] Wherein, the red-light epitaxial layer includes a first p-type layer, a first light-emitting layer, and a first n-type layer stacked in sequence.

[0053] In the red-light epitaxial layer, the first p-type layer includes a p-type AlInP layer.

[0054] Wherein, the first light-emitting layer includes alternately grown AlGaInP quantum well layers and AlGaInP quantum barrier layers, and 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.

[0055] Wherein, the first n-type layer includes an n-type AlGaInP current spreading layer.

[0056] In the embodiments of the present disclosure, the green-light epitaxial layer includes a second p-type layer, a second light-emitting layer, and a second n-type layer stacked in sequence.

[0057] In the green-light epitaxial layer, the second p-type layer includes a p-type GaN layer.

[0058] Wherein, 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.

[0059] Wherein, the second n-type layer includes an n-type GaN layer.

[0060] In an embodiment of the present disclosure, the blue light epitaxial layer includes a third p-type layer, a third light-emitting layer, and a third n-type layer that are stacked in sequence.

[0061] In the blue light epitaxial layer, the third p-type layer includes a p-type GaN layer.

[0062] Among them, 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.

[0063] Among them, the third n-type layer includes an n-type GaN layer.

[0064] Optionally, the thickness of the pixel chip is 2 μm to 10 μm.

[0065] Exemplarily, the thickness of the red light epitaxial layer is 5 μm, the thickness of the green light epitaxial layer is 8 μm, and the thickness of the blue light epitaxial layer is 6 μm.

[0066] Step 202: Bond each pixel chip to the circuit board 12 so that the side of the pixel chip away from the temporary substrate 11 is connected to the circuit board 12.

[0067] Among them, the circuit board includes: a base board, a first conductive layer, and a second conductive layer. The first conductive layer and the second conductive layer are respectively located on opposite sides of the base board, and through holes are provided on the base board. The through holes are filled with a conductive material. The first conductive layer and the second conductive layer are electrically connected through the conductive material. Solder joints are further provided on the surface of the first conductive layer or the second conductive layer. The solder joints are used to bond with the pixel chip so that the pixel chip is electrically connected to the conductive layer.

[0068] Specifically, it may include: as Figure 3 shown, use laser welding or thermocompression bonding process to bond each pixel chip and the solder joints on the circuit board 12 in one-to-one correspondence.

[0069] In an embodiment of the present disclosure, forming the encapsulation glue layer 50 that wraps each pixel chip may include two implementation manners. Among them, one implementation manner is Steps 203 to 204, and the specific processes of Steps 203 to 204 can be referred to Figure 3 ; another implementation manner is Steps 205 to 206.

[0070] Step 203: Inject encapsulation glue into the gap between the circuit board 12 and the temporary substrate 11 through the glue injection hole 110.

[0071] Figure 4 is a top view of a temporary substrate 11 provided by an embodiment of the present disclosure. As Figure 3 、 4As shown, the surface of the temporary substrate 11 has glue injection holes 110 penetrating through the temporary substrate 11, and the glue injection holes 110 are arranged at intervals from the pixel chips.

[0072] Step 204: After the encapsulation glue fills the gaps between the pixel chips, cure the encapsulation glue to obtain the encapsulation glue layer 50.

[0073] In the above implementation, the glue injection holes 110 are formed on the surface of the temporary substrate 11, which facilitates the rapid injection of the encapsulation glue into the gap between the temporary substrate 11 and the circuit board 12; compared with the injection method from the side of the gap between the temporary substrate 11 and the circuit board 12, the injection method from the glue injection holes 110 is more likely to inject the encapsulation glue into the central area of the temporary substrate 11 to fill the gaps between the pixel chips.

[0074] Optionally, the light absorption rate of the encapsulation glue layer 50 is greater than or equal to 0.8. Wrapping the pixel chips with the encapsulation glue layer 50 having a light absorption rate greater than or equal to 0.8 can block the lateral light emission of the pixel chips and improve the front light emission effect of the light emitting device.

[0075] Exemplarily, the encapsulation glue layer 50 can be black, and black is more likely to absorb light to avoid more light emitting from the side of the pixel chips. Moreover, during the injection of the encapsulation glue, the black encapsulation glue is easier to observe, which is beneficial for technicians to accurately judge whether the encapsulation glue completely wraps each pixel chip.

[0076] Optionally, the diameter of the glue injection hole 110 is less than or equal to the gap between adjacent pixel chips. This can prevent the surface of the pixel chip far from the circuit board 12 from being exposed in the area where the glue injection hole 110 is formed on the temporary substrate 11, so as to prevent the encapsulation glue from adhering to the surface of the pixel chip far from the circuit board 12 during the glue injection process.

[0077] Exemplarily, the ratio of the diameter of the glue injection hole 110 to the gap between adjacent pixel chips is 1 / 2.

[0078] Exemplarily, as Figure 4 shown, the surface of the temporary substrate 11 has a glue injection hole 110, and the glue injection hole 110 is located at the geometric center of the temporary substrate 11.

[0079] Setting the glue injection hole 110 at the geometric center of the temporary substrate 11 makes it easier for the encapsulation glue injected from the glue injection hole 110 to enter the central area of the temporary substrate 11 to fill the gaps between the pixel chips.

[0080] Moreover, during the glue injection process, the encapsulation glue will gradually expand from the central area of the temporary substrate 11 to the edge area of the temporary substrate 11. And the edge area of the temporary substrate 11 is easier to observe. Therefore, when the encapsulation glue overflows from the edge area of the temporary substrate 11, technicians can judge that the glue injection is completed.

[0081] Exemplarily, the plate surface of the temporary substrate 11 has a plurality of glue injection holes 110, and the plurality of glue injection holes 110 are arranged at circumferential intervals with the geometric center of the temporary substrate 11 as the center of the circle.

[0082] Exemplarily, the plate surface of the temporary substrate 11 has a plurality of glue injection holes 110, and the plurality of glue injection holes 110 are arranged in an array.

[0083] Compared with setting one glue injection hole 110, setting a plurality of glue injection holes 110 can improve the speed of injecting the encapsulation glue into the gap between the circuit substrate 12 and the temporary substrate 11, so that the gap between the pixel chips can be quickly filled.

[0084] Optionally, obtaining the encapsulation glue layer 50 by curing the encapsulation glue can also include two implementation manners.

[0085] The first curing method is heat curing. Specifically, it can include: controlling the temperature to rise above 50°C and heating and curing the encapsulation glue; controlling the temperature to rise above 150°C and baking the encapsulation glue for 1 h to 2 h to obtain the encapsulation glue layer 50.

[0086] Among them, first controlling the temperature to rise above 50°C can accelerate the curing speed and achieve rapid curing of the encapsulation glue; then controlling the temperature to rise above 150°C and baking the encapsulation glue can make the encapsulation glue completely cured.

[0087] The second curing method is curing by ultraviolet light irradiation. Specifically, it can include: irradiating the encapsulation glue with ultraviolet light for 1 min to 10 min to obtain the encapsulation glue layer 50.

[0088] Using the method of ultraviolet light irradiation to cure the encapsulation glue has a faster speed and can improve the preparation efficiency of the encapsulation glue layer 50.

[0089] Step 205: Place the circuit substrate 12 bound with the pixel chips in the glue injection container 60.

[0090] Figure 5 It is a schematic diagram of the encapsulation of a light-emitting device provided by an embodiment of the present disclosure. As Figure 5 shown, the glue injection container 60 is filled with liquid encapsulation glue X, and the liquid level height of the encapsulation glue X is greater than the sum of the thicknesses of the pixel chips 20 and the circuit substrate 12, that is, the encapsulation glue X covers the pixel chips and the circuit substrate 12.

[0091] As Figure 5 shown, the surface of the glue injection container 60 has an air extraction hole 61 communicated with the inner cavity of the glue injection container 60.

[0092] Step 206: Evacuate the inner cavity of the glue injection container 60 through the air extraction hole 61 to reduce the air pressure inside the glue injection container 60, so that the encapsulation glue fills the gaps between the pixel chips.

[0093] In the above implementation, the air pressure inside the glue injection container 60 is reduced by evacuation, and the residual air inside the glue injection container 60 is removed, which can accelerate the injection of the encapsulation glue into the gaps between the pixel chips and fully wrap the pixel chips.

[0094] Step 207: Remove the temporary substrate 11 to expose the surface of the pixel chip away from the circuit board 12.

[0095] Specifically, it may include: laser peeling the temporary substrate 11 and cleaning the glue layer on the surface of the pixel chip with a cleaning agent to expose the pixel chip.

[0096] Among them, the temporary substrate 11 and the pixel chip are usually bonded with a photosensitive glue. After the temporary substrate 11 is peeled off by laser, there is usually still some photosensitive glue remaining on the surface of the pixel chip. Therefore, a cleaning agent for the photosensitive glue can be used to clean the photosensitive glue remaining on the surface of the pixel chip, which can make the surface of the pixel chip cleaner.

[0097] As Figure 3 shown, after step 207, ISO etching can also be performed to etch the appearance size of the light-emitting device, and multiple light-emitting devices can be obtained by laser scribing.

[0098] The embodiment of the present disclosure provides a light-emitting device, and the light-emitting device is encapsulated by using the encapsulation method of the light-emitting device as described above. Figure 6 is a top view of a light-emitting device provided by an embodiment of the present disclosure. Figure 6 Schematically shows the state before the encapsulation glue layer 50 is formed on the circuit board 12. Figure 7 is a top view of a light-emitting device provided by an embodiment of the present disclosure. Figure 7 Schematically shows the state after the encapsulation glue layer 50 is formed on the circuit board 12.

[0099] As Figure 6 、 7 shown, the light-emitting device includes: a circuit board 12, a plurality of pixel chips, and an encapsulation glue layer 50; the plurality of pixel chips are all located on the surface of the circuit board 12, the encapsulation glue layer 50 is located on the surface of the circuit board 12 and wraps each pixel chip, and the surface of the encapsulation glue layer 50 away from the circuit board 12 is flush with the surface of the pixel chip away from the circuit board 12.

[0100] Optionally, as Figure 6 、 7As shown, a plurality of pixel chips include: a first pixel chip 21, a second pixel chip 22, and a third pixel chip 23, and the light-emitting colors of the first pixel chip 21, the second pixel chip 22, and the third pixel chip 23 are all different.

[0101] Optionally, as Figure 6 shown, the light-emitting device further includes a first pad 31, a second pad 32, a third pad 33, and a fourth pad 34. The first pad 31, the second pad 32, the third pad 33, and the fourth pad 34 are all located on the surface of the circuit board 12 and are connected to the solder joints of the circuit board 12.

[0102] As Figure 6 shown, the first electrodes 41 of the first pixel chip 21, the first electrodes 41 of the second pixel chip 22, and the first electrodes 41 of the third pixel chip 23 are all connected to the first pad 31.

[0103] In this way, the first pad 31 is connected to the first electrodes 41 of each pixel chip, and the first pad 31 is used as a common pad, thereby avoiding setting more pads on the flat layer to reduce the size of the light-emitting device.

[0104] As Figure 6 shown, the second electrode 42 of the first pixel chip 21 is connected to the second pad 32, the second electrode 42 of the second pixel chip 22 is connected to the third pad 33, and the second electrode 42 of the third pixel chip 23 is connected to the fourth pad 34.

[0105] In the embodiments of the present disclosure, a pad is separately provided for each pixel chip, and whether the pixel chip emits light can be controlled by controlling the power supply to the pad corresponding to the pixel chip.

[0106] In the embodiments of the present disclosure, the plurality of pixel chips include a first pixel chip 21 that emits red light, a second pixel chip 22 that emits green light, and a third pixel chip 23 that emits blue light.

[0107] The difference between the first pixel chip 21, the second pixel chip 22, and the third pixel chip 23 lies in the different light-emitting colors of the epitaxial layers.

[0108] For the first pixel chip 21, the epitaxial layer is a red-light epitaxial layer. For the second pixel chip 22, the epitaxial layer is a green-light epitaxial layer. For the third pixel chip 23, the epitaxial layer is a blue-light epitaxial layer.

[0109] Among them, the red-light epitaxial layer includes a first p-type layer, a first light-emitting layer, and a first n-type layer stacked in sequence.

[0110] In the red-light epitaxial layer, the first p-type layer includes a p-type AlInP layer.

[0111] Among them, the first light-emitting layer includes alternately grown AlGaInP quantum well layers and AlGaInP quantum barrier layers, where 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.

[0112] Among them, the first n-type layer includes an n-type AlGaInP current spreading layer.

[0113] In the embodiment of the present disclosure, the green light epitaxial layer includes a second p-type layer, a second light-emitting layer, and a second n-type layer stacked in sequence.

[0114] In the green light epitaxial layer, the second p-type layer includes a p-type GaN layer.

[0115] Among them, 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.

[0116] Among them, the second n-type layer includes an n-type GaN layer.

[0117] In the embodiment of the present disclosure, the blue light epitaxial layer includes a third p-type layer, a third light-emitting layer, and a third n-type layer stacked in sequence.

[0118] In the blue light epitaxial layer, the third p-type layer includes a p-type GaN layer.

[0119] Among them, 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.

[0120] Among them, the third n-type layer includes an n-type GaN layer.

[0121] Optionally, the thickness of the pixel chip is 2 μm to 10 μm.

[0122] Exemplarily, the thickness of the red light epitaxial layer is 5 μm, the thickness of the green light epitaxial layer is 8 μm, and the thickness of the blue light epitaxial layer is 6 μm.

[0123] Exemplarily, the substrate may be a sapphire substrate or a glass substrate.

[0124] Optionally, the passivation layer may be a silicon oxide layer. Among them, the thickness of the silicon oxide layer may be 3 μm to 30 μm.

[0125] Exemplarily, the thickness of the passivation layer may be 10 μm.

[0126] Optionally, the passivation layer may be a Distributed Bragg Reflection (DBR) layer, which includes multiple periodically alternating stacked SiO 2 layers and TiO 2 layers. And the number of periods of the DBR layer can be between 20 and 50. For example, the number of periods of the DBR layer is 32.

[0127] Among them, the thickness of the SiO 2 layer in the DBR layer can be 800 angstroms to 1200 angstroms, and the thickness of the TiO 2 layer can be 500 angstroms to 900 angstroms.

[0128] In the embodiments of the present disclosure, the first electrode 41 of each pixel chip is connected to the n-type layer, and the second electrode 42 of each pixel chip is connected to the p-type layer. And the first electrode 41 is connected to the first pad 31, so the first pad 31 is the negative pad. Correspondingly, the second pad 32, the third pad 33, and the fourth pad 34 are all positive pads.

[0129] The embodiments of the present disclosure provide a display panel, which includes a plurality of light-emitting devices, a driving integrated circuit (IC), and a circuit board as described above. The plurality of light-emitting devices and the driving IC are both located on the circuit board.

[0130] Exemplarily, a plurality of light-emitting devices are arranged in an array on the circuit board.

[0131] Among them, the driving IC is electrically connected to the circuit board through the driving traces on the circuit board, and the solder pads of the plurality of light-emitting devices are also electrically connected to the driving traces on the circuit board. In this way, the driving IC can control each light-emitting device through the driving traces.

[0132] The above is not any form of limitation to the present disclosure. Although the present disclosure has been disclosed as above through embodiments, it is not intended to limit the present disclosure. Any person skilled in the art, without departing from the scope of the technical solution of the present disclosure, may make some changes or modifications to the above-disclosed technical content to obtain equivalent embodiments with equivalent changes. However, as long as it does not depart from the content of the technical solution of the present disclosure, any simple modification, equivalent change, and modification made to the above embodiments according to the technical essence of the present disclosure still fall within the scope of the technical solution of the present disclosure.

Claims

1. A packaging method for a light emitting device, characterized in that: The packaging method comprises: transferring a plurality of pixel chips (20) onto a surface of a temporary substrate (11); Binding each pixel chip (20) to a circuit substrate (12) so that a side of the pixel chip (20) away from the temporary substrate (11) is connected to the circuit substrate (12); Filling packaging glue between the circuit substrate (12) and the temporary substrate (11) to form a packaging glue layer (50) that wraps each pixel chip (20); The temporary substrate (11) is removed to expose the surface of the pixel chip (20) away from the circuit substrate (12).

2. The packaging method according to claim 1, characterized in that: The surface of the temporary substrate (11) has a glue injection hole (110) penetrating the temporary substrate (11), and the glue injection hole (110) and the pixel chip (20) are arranged at intervals; Filling packaging glue between the circuit substrate (12) and the temporary substrate (11) to form a packaging glue layer (50) that wraps each pixel chip (20) comprises: Injecting packaging glue into the gap between the circuit substrate (12) and the temporary substrate (11) through the glue injection hole (110); After the encapsulation adhesive fills the gaps between the pixel chips (20), the encapsulation adhesive is cured to obtain the encapsulation adhesive layer (50).

3. The packaging method according to claim 2, characterized in that: The plate surface of the temporary substrate (11) has one of the glue injection holes (110), and the glue injection hole (110) is located at the geometric center of the temporary substrate (11); or, The plate surface of the temporary substrate (11) has a plurality of the glue injection holes (110), and the plurality of the glue injection holes (110) are arranged at intervals in the circumferential direction with the geometric center of the temporary substrate (11) as the center; or, The surface of the temporary substrate (11) has a plurality of glue injection holes (110), and the plurality of glue injection holes (110) are arranged in an array.

4. The packaging method according to claim 3, characterized in that: Curing the encapsulation adhesive to obtain the encapsulation adhesive layer (50) comprises: Control the temperature to rise above 50°C to heat and cure the packaging glue; Control the temperature to rise to above 150° C., bake the encapsulation glue for 1 to 2 hours, and obtain the encapsulation glue layer (50); or, The packaging glue is irradiated with ultraviolet light for 1 to 10 minutes to obtain the packaging glue layer (50).

5. The packaging method according to claim 2, characterized in that: The diameter of the glue injection hole (110) is smaller than or equal to the gap between adjacent pixel chips.

6. The packaging method according to claim 1, characterized in that: Filling packaging glue between the circuit substrate (12) and the temporary substrate (11) to form a packaging glue layer (50) that wraps each pixel chip comprises: The circuit substrate (12) bound with the pixel chip is placed in a glue injection container (60), and liquid packaging glue is injected into the glue injection container (60), wherein the liquid level of the packaging glue is greater than the sum of the thicknesses of the pixel chip and the circuit substrate (12).

7. The packaging method according to claim 6, characterized in that: The surface of the glue injection container (60) has an air extraction hole (61) which is in communication with the inner cavity of the glue injection container (60); After placing the circuit substrate (12) bound with the pixel chip in a glue injection container (60), the method further comprises: The inner cavity of the glue injection container (60) is evacuated through the air extraction hole (61), so that the air pressure in the glue injection container (60) is reduced, allowing the packaging glue to fill the gaps between the pixel chips.

8. The packaging method according to any one of claims 1 to 7, characterized in that: Removing the temporary substrate (11) to expose the surface of the pixel chip away from the circuit substrate (12) comprises: The temporary substrate (11) is peeled off by laser, and the adhesive layer on the surface of the pixel chip is cleaned by a cleaning agent to expose the pixel chip.

9. A light emitting device, characterized in that: The light emitting device comprises: a circuit substrate (12), a plurality of pixel chips and a packaging adhesive layer (50); The plurality of pixel chips are all located on the surface of the circuit substrate (12); the encapsulation adhesive layer (50) is located on the surface of the circuit substrate (12) and wraps each of the pixel chips; the surface of the encapsulation adhesive layer (50) away from the circuit substrate (12) is flush with the surface of the pixel chip away from the circuit substrate (12).

10. A display panel, characterized in that: The display panel comprises a plurality of light emitting devices as claimed in claim 9, a driving integrated circuit and a circuit board, wherein the plurality of light emitting devices and the driving integrated circuit are both located on the circuit board.

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