Light-emitting chip, display device, and chip transfer method

Abstract

The present application provides a light-emitting chip, a display device and a chip transfer method. The light-emitting chip includes an epitaxial layer, an electrode layer and a limiting component. The electrode layer is arranged on the first side of the epitaxial layer in the thickness direction, and the electrode layer includes a first electrode. The limiting component is arranged on the first side of the epitaxial layer, and the positive projection of the limiting component on the epitaxial layer is staggered with the positive projection of the first electrode on the epitaxial layer, and in the direction away from the epitaxial layer, the limiting component at least partially protrudes from the first electrode. The height of the limiting component in the thickness direction changes as the distance between it and the first electrode changes, so as to form a tip protruding from the first electrode. In the embodiment of the present application, since the tip itself has a relatively sharp structure, it can more easily enter a deeper position in the buffer material, thereby being able to drive the first electrode close to the circuit substrate, and then the bonding between the light-emitting chip and the circuit substrate can be achieved without large pressure, thereby improving the bonding yield.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to a light-emitting chip, a display device, and a chip transfer method. Background Art

[0002] Light-emitting diodes (LEDs) are semiconductor diodes that convert electrical energy into light and are widely used in display devices and backlighting. The chip is the core component of an LED, and microLED chips are micron-sized diode chips.

[0003] After the LED chips are manufactured, they usually need to be transferred in batches so that they can be transferred to the corresponding circuit to achieve conduction and illumination. However, the current bonding yield of the light-emitting chips after transfer is low, which leads to increased costs. Summary of the Invention

[0004] The embodiments of the present application provide a light-emitting chip, a display device, and a chip transfer method, which can improve the bonding effect between the light-emitting chip and the circuit substrate.

[0005] In a first aspect, an embodiment of the present application provides a light-emitting chip, comprising an epitaxial layer, an electrode layer, and a limiting component, wherein the electrode layer is arranged on a first side in a thickness direction of the epitaxial layer, and the electrode layer comprises a first electrode.

[0006] The limiting assembly is disposed on a first side of the epitaxial layer, with an orthographic projection of the limiting assembly on the epitaxial layer being offset from an orthographic projection of the first electrode on the epitaxial layer, and at least partially protruding beyond the first electrode in a direction away from the epitaxial layer. The height of the limiting assembly in the thickness direction varies as the distance between the limiting assembly and the first electrode changes, thereby forming a tip portion protruding beyond the first electrode.

[0007] In a second aspect, an embodiment of the present application provides a display device, comprising the light-emitting chip in any of the aforementioned embodiments.

[0008] In a third aspect, a chip transfer method is provided, comprising:

[0009] Arranging a plurality of light-emitting chips on one side of the substrate to be transferred, wherein the light-emitting chips are the light-emitting chips of any of the aforementioned embodiments, and the electrode layer is located on the side of the epitaxial layer away from the substrate to be transferred;

[0010] A plurality of first conductive portions and a soft adhesive layer are provided on one side of the target substrate, wherein at least a portion of the soft adhesive layer surrounds the outer periphery of the first conductive portion, and the hardness of the soft adhesive layer is less than that of the limiting component;

[0011] The substrate to be transferred and the target substrate are arranged opposite to each other and spaced apart, and the light-emitting chip is dropped onto the target substrate, with the tip portion embedded in the soft adhesive layer, and the first electrode is in contact with and connected to the first conductive portion.

[0012] In some embodiments, in the thickness direction of the target substrate, the height of the soft adhesive layer is smaller than the height of the first conductive portion, and the height difference between the soft adhesive layer and the first conductive portion is no greater than 2 μm.

[0013] The embodiments of the present application provide a light-emitting chip, a display device, and a chip transfer method. Since the tip protrudes from the first electrode, during the laser transfer process, the tip will be embedded in the buffer material above the circuit substrate before the first electrode. Since the tip itself has a relatively sharp structure, it can more easily penetrate into a deeper position in the buffer material, thereby driving the first electrode close to the circuit substrate, and then achieving bonding between the light-emitting chip and the circuit substrate without requiring large pressure, thereby improving the bonding yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0015] Figure 1 This is a schematic structural diagram of a light-emitting chip provided in an embodiment of the present application;

[0016] Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure of AA;

[0017] Figure 3 This is a structural diagram of another light-emitting chip provided in an embodiment of the present application;

[0018] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure of the middle BB;

[0019] Figure 5 yes Figure 3 A schematic diagram of the structure of transferring the light-emitting chip to the circuit substrate;

[0020] Figure 6 1 is a schematic cross-sectional view of another light-emitting chip provided in an embodiment of the present application;

[0021] Figure 7 This is a structural diagram of another light-emitting chip provided in an embodiment of the present application;

[0022] Figure 8 is a structural schematic diagram of a display device provided in an embodiment of the present application;

[0023] Figure 9 This is a flow chart of a chip transfer method provided in an embodiment of the present application;

[0024] Figures 10a to 10c This is a process structure diagram of a chip transfer method provided in an embodiment of the present application.

[0025] Marking Description:

[0026] 1. epitaxial layer; 11. first semiconductor layer; 12. active layer; 13. second semiconductor layer;

[0027] 2. Electrode layer; 21. First electrode; 22. Second electrode;

[0028] 3. Limiting assembly; 31. Tip portion; 32. First limiting portion; 33. Second limiting portion; 34. Microtubule structure;

[0029] 4. Circuit substrate; 41. Soft rubber layer; 42. First conductive portion; 43. Second conductive portion;

[0030] 5. Substrate to be transferred;

[0031] O, ring structure;

[0032] L, spacing; H, height; ΔH, height difference;

[0033] X, first direction; Y, thickness direction. DETAILED DESCRIPTION

[0034] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0035] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article, or device comprising the elements.

[0036] In the manufacturing process of micro-LED displays, the light-emitting chip is usually first obtained on a sapphire substrate, then separated from the substrate and transferred to the corresponding circuit substrate. Currently, the industry's process development direction is to directly transfer the light-emitting chip to the corresponding circuit substrate and complete the bonding using laser transfer technology. Specifically, a soft adhesive layer is applied to the circuit substrate to receive the light-emitting chip released by the laser. Then, the bonding between the light-emitting chip and the circuit substrate is achieved through methods such as heat pressing.

[0037] However, in existing technologies, the bonding yield between the circuit substrate and the light-emitting chip is often low. The applicant's research has found that this is because the soft adhesive layer hinders the bonding between the light-emitting chip and the circuit substrate. Extruding the soft adhesive layer by increasing pressure consumes significant energy and can easily damage the light-emitting chip, resulting in a decrease in yield.

[0038] To solve the above problem, please refer to Figures 1 to 5 An embodiment of the present application provides a light-emitting chip, including an epitaxial layer 1, an electrode layer 2 and a limiting component 3, wherein the electrode layer 2 is arranged on a first side of the epitaxial layer 1 in a thickness direction Y, and the electrode layer 2 includes a first electrode 21.

[0039] The limiting component 3 is disposed on the first side of the epitaxial layer 1. The orthographic projection of the limiting component 3 on the epitaxial layer 1 is offset from the orthographic projection of the first electrode 21 on the epitaxial layer 1. In the direction away from the epitaxial layer 1, the limiting component 3 at least partially protrudes beyond the first electrode 21. The height of the limiting component 3 in the thickness direction Y changes as the distance between the limiting component 3 and the first electrode 21 changes, thereby forming a tip portion 31 that protrudes beyond the first electrode 21.

[0040] In the embodiment of the present application, the light-emitting chip may include but is not limited to a Mini LED (Mini Light Emitting Diode, sub-millimeter light-emitting diode) chip, a Micro LED (Micro Light Emitting Diode, micro light-emitting diode) chip or other various LED (Light Emitting Diode, light-emitting diode) chips.

[0041] The epitaxial layer 1 can provide conditions for the preparation of the electrode layer 2. Exemplarily, the epitaxial layer 1 includes a first semiconductor layer 11, an active layer 12, and a second semiconductor layer 13 stacked in sequence, and an insulating passivation layer (not shown in the figure) covering these layers, etc., wherein the first semiconductor layer 11 and the second semiconductor layer 13 can be an N-type semiconductor layer and a P-type semiconductor layer respectively, the active layer 12 includes a quantum well layer, etc., and the insulating passivation layer can be an insulating material with relatively stable properties including but not limited to silicon dioxide (SiO2), aluminum oxide (Al2O3), etc.

[0042] The electrode layer 2 is formed on one side of the epitaxial layer 1 and includes a first electrode 21. The first electrode 21 can be a P-type electrode or an N-type electrode. Specifically, when the first electrode 21 contacts the N-type semiconductor layer, the first electrode 21 is an N-type electrode; when the first electrode 21 contacts the P-type semiconductor layer, the first electrode 21 is a P-type electrode.

[0043] In addition, the light emitting chip further includes a second electrode 22 in addition to the first electrode 21. The first electrode 21 and the second electrode 22 can be located on the same side of the epitaxial layer 1 or on different sides of the epitaxial layer 1. This embodiment of the present application does not limit this. When the light emitting chip is a vertical structure, such as Figure 2 The second electrode 22 is located on the side of the epitaxial layer 1 away from the first electrode 21; when the light emitting chip is a face-up structure or a flip-chip structure, as shown in FIG. Figure 4 As shown, the second electrode 22 is also located in the electrode layer 2 .

[0044] The limiting component 3 and the electrode layer 2 are located on the same side of the epitaxial layer 1, and the orthographic projection of the limiting component 3 on the epitaxial layer 1 is staggered with the orthographic projection of the first electrode 21 on the epitaxial layer 1. Therefore, the existence of the limiting component 3 will not affect the electrical connection between the first electrode 21 and the corresponding conductive part on the circuit substrate 4.

[0045] At the same time, in the direction away from the epitaxial layer 1, the limiting component 3 at least partially protrudes from the first electrode 21. This indicates that in the thickness direction Y, the distance between at least part of the limiting component 3 and the epitaxial layer 1 is greater than the distance between any position of the first electrode 21 and the epitaxial layer 1. The limiting component 3 can be arranged in the electrode layer 2 at the same time as the first electrode 21, or it can be arranged on the side of the electrode layer 2 facing away from the epitaxial layer 1. The presence of the limiting component 3 can, to a certain extent, play a role in positioning and limiting during the transfer of the light-emitting chip, ensuring that the light-emitting chip can be transferred to a specific position and improving transfer accuracy.

[0046] In addition, in the embodiment of the present application, the height of the limiting component 3 at different positions is different, and the height of the limiting component 3 in the thickness direction Y changes as the distance between the limiting component 3 and the first electrode 21 changes. The "change in the distance between the limiting component 3 and the first electrode 21" mentioned here means that the distance between the limiting component 3 and the first electrode 21 at different positions perpendicular to the thickness direction Y is different.

[0047] Since the heights of the limiting component 3 at different positions in the thickness direction Y are different, the limiting component 3 can form a tip portion 31 protruding from the first electrode 21. Figure 2In the figure, the tip portion 31 is the portion of the limiting component 3 located within the dotted box. Specifically, the tip portion 31 represents the portion of the limiting component 3 that is away from the epitaxial layer 1. It also means that the distance between any position of the tip portion 31 and the epitaxial layer 1 in the thickness direction is greater than the distance between any position of the first electrode 21 and the epitaxial layer 1.

[0048] Since the tip portion 31 protrudes from the first electrode 21, during the laser transfer process, the tip portion 31 will be embedded in the soft glue layer 41 above the circuit substrate 4 before the first electrode 21. Since the tip portion 31 itself has a relatively sharp structure, it can more easily enter a deeper position in the soft glue layer 41, thereby being able to drive the first electrode 21 close to the circuit substrate 4, and then achieve bonding between the light-emitting chip and the circuit substrate 4 without requiring large pressure, thereby improving the bonding yield. The embodiment of the present application does not limit the material of the limiting component 3. As long as the hardness of the limiting component 3 is greater than the hardness of the soft glue layer 41, the limiting component 3 can enter the soft glue layer 41.

[0049] It should be noted that the embodiment of the present application does not limit the variation in height of the limiting component 3 at different positions, as long as the limiting component 3 can form a tip portion 31 protruding from the first electrode 21. In addition, the light-emitting chip provided in the embodiment of the present application may include other functional film layers in addition to the epitaxial layer 1, the electrode layer 2, the limiting component 3, and the second electrode 22, and the embodiment of the present application also does not limit this.

[0050] In some embodiments, as Figure 4 and Figure 5 As shown, the limiting assembly 3 includes a first limiting portion 32 distributed around the circumference of the first electrode 21 , and the height of the first limiting portion 32 in the thickness direction Y tends to gradually increase in the direction away from the first electrode 21 .

[0051] The first limiting portion 32 is distributed around the outer periphery of the first electrode 21. In addition to helping the first electrode 21 to more easily approach the circuit substrate 4 during the transfer process, the first limiting portion 32 can also protect the first electrode 21 when the light-emitting chip is used to emit light, reduce the risk of dust and impurities contacting the first electrode 21, and improve reliability.

[0052] It should be noted that the first limiting portion 32 can be a one-piece structure or can be composed of multiple microstructures. Optionally, the first limiting portion 32 includes multiple microtube structures, and the multiple microtube structures are evenly arranged on the outer periphery of the first electrode 21 to protect the first electrode 21.

[0053] The height of the first limiting portion 32 in the thickness direction Y gradually increases in a direction away from the first electrode 21. That is, the farther away from the first electrode 21, the higher the height of the first limiting portion 32. Therefore, at least part of the tip portion 31 is located at the end of the first limiting portion 32 away from the first electrode 21.

[0054] In the embodiment of the present application, the height of the first limiting portion 32 is gradually increased in the direction away from the first electrode 21, so that the end of the first limiting portion 32 away from the first electrode 21 can form a pointed portion 31. Therefore, the first limiting portion 32 can protect the first electrode 21 while also helping the first electrode 21 to more easily approach the circuit substrate 4 during the laser transfer process, thereby improving the bonding yield.

[0055] In some embodiments, in a direction away from the first electrode 21 , the height of the first limiting portion 32 in the thickness direction Y increases in a gradient or linear manner.

[0056] Compared to other dimensional change methods, gradient or linear increase is simpler and also makes it easier to control the shape and size of the first limiter 32, thereby reducing the difficulty of manufacturing the first limiter 32. Furthermore, the linear increase method helps to make the outer surface of the tip 31 smoother, making it easier for the tip 31 to penetrate deeply into the soft rubber layer 41, further improving the bonding effect.

[0057] In some embodiments, the first limiting portions 32 are symmetrically distributed around the first electrode 21 .

[0058] During the laser transfer process, the tip 31 on the first limiting portion 32 will contact the soft adhesive layer 41 before the first electrode 21. If the first limiting portion 32 is only provided on one side of the first electrode 21, when the tip 31 contacts the soft adhesive layer 41, the light-emitting chip will easily tilt toward the other side of the first electrode 21, resulting in transfer deviation.

[0059] To reduce the risk of this phenomenon, the present embodiment of the present invention symmetrically distributes the first stoppers 32 on both sides of the first electrode 21. This allows the light-emitting chip to be vertically embedded in the soft adhesive layer 41 and bonded to the circuit substrate 4 with a greater probability during the transfer process, thereby improving transfer accuracy. Optionally, the first stoppers 32 are annular and symmetrically surround the outer periphery of the first electrode 21.

[0060] In some embodiments, see Figure 6 The first limiting portion 32 includes a plurality of microtube structures 34, and the plurality of microtube structures 34 are nested multilayer structures around the first electrode 21, and the heights of different microtube structures 34 in the thickness direction Y tend to gradually increase in the direction away from the first electrode 21.

[0061] The microtubule structure 34 is a micro-tubular structure formed by nanoimprinting or other methods. Multiple microtubule structures 34 are arranged side by side in a direction away from the first electrode 21. The multiple microtubule structures 34 are combined to form a first stopper 32. The farther the microtubule structure 34 is from the first electrode 21, the higher its height in the thickness direction Y. The tip of the tip portion 31 is located at the end of the microtubule structure 34 with the highest height, away from the epitaxial layer 1.

[0062] In the embodiment of the present application, multiple microtube structures 34 are included. By controlling the relative distance between the microtube structures 34 and the first electrode 21 and the height of the microtube structures 34 in the thickness direction Y, a first stopper 32 with a gradually varying height is formed. Furthermore, the multiple microtube structures 34 form a nested, multi-layered retaining wall structure away from the first electrode 21, providing multi-layer protection for the first electrode 21 and improving the protective effect.

[0063] In some embodiments, as Figure 6 As shown, the diameter of the micro-tube structure 34 decreases as the height of the micro-tube structure 34 in the thickness direction Y increases.

[0064] As can be seen from the foregoing, the first stopper 32 includes a tip portion 31 protruding from the first electrode 21. Furthermore, the first stopper 32 includes multiple microtube structures 34 of varying heights. The end of the tallest microtube structure 34, located away from the epitaxial layer 1, is the tip of the tip portion 31. Generally, the sharper the tip portion 31, the easier it is to penetrate deep into the soft plastic layer.

[0065] On this basis, the embodiment of the present application sets the tube diameters of different microtube structures 34 to different sizes. The microtube structure 34 with higher height has a smaller tube diameter, which helps to form a sharp tip 31, so that the first limiting portion 32 can enter deeper into the soft rubber layer during the transfer process, thereby further improving the bonding effect between the light-emitting chip and the circuit substrate.

[0066] In some embodiments, see Figures 3 to 6 The electrode layer 2 further includes a second electrode 22. The orthographic projection of the limiting component 3 on the epitaxial layer 1 is offset from the orthographic projection of the second electrode 22 on the epitaxial layer 1. The limiting component 3 includes a second limiting portion 33 distributed around the circumference of the second electrode 22. The height of the second limiting portion 33 in the thickness direction Y gradually increases in a direction away from the second electrode 22.

[0067] One of the first electrode 21 and the second electrode 22 is an N-type electrode, contacting the N-type semiconductor layer; the other is a P-type electrode, contacting the P-type semiconductor layer. Because the second electrode 22 and the first electrode 21 are located on the same side of the epitaxial layer 1, like the first electrode 21, the second electrode 22 also needs to be electrically connected to the corresponding conductive structure on the circuit substrate 4.

[0068] In order to improve the electrical connection reliability between the second electrode 22 and the corresponding conductive structure on the circuit substrate 4, the embodiment of the present application adds a second limiting portion 33 on the basis of the first limiting portion 32. The second limiting portion 33 is distributed around the circumference of the second electrode 22 and also has a tip portion 31. The structure of the second limiting portion 33 is similar to that of the first limiting portion 32. For details, please refer to the above description of the first limiting portion 32. The embodiment of the present application will not be repeated here. And the material of the first limiting portion 32 is

[0069] Furthermore, the present embodiment does not impose any restrictions on the height of the tip portion 31 on the first limiting portion 32 and the tip portion 31 on the second limiting portion 33. That is, the tip portion 31 on the first limiting portion 32 can be slightly higher than the tip portion 31 on the second limiting portion 33, or the tip portion 31 on the second limiting portion 33 can be slightly higher than the tip portion 31 on the first limiting portion 32. Optionally, the tip portion 31 on the first limiting portion 32 and the tip portion 31 on the second limiting portion 33 are located at the same height, thereby further reducing the risk of the light-emitting chip tilting during transfer and improving reliability.

[0070] In some optional embodiments, in a direction away from the second electrode 22 , the height of the second limiting portion 33 in the thickness direction Y increases in a gradient or linear manner.

[0071] In some optional embodiments, the first limiting portions 32 are symmetrically distributed around the second electrode 22 .

[0072] In some optional embodiments, the second limiting portion 33 includes multiple microtube structures 34 and presents a nested multi-layer structure around the second electrode 22, and in the direction away from the second electrode 22, the heights of different microtube structures 34 in the thickness direction Y tend to gradually increase.

[0073] In some optional embodiments, the diameter of the micro-tube structure 34 in the second limiting portion 33 decreases as the height of the micro-tube structure 34 in the thickness direction Y increases.

[0074] In some embodiments, as Figure 4 As shown, the first limiting portion 32 and the second limiting portion 33 located between the first electrode 21 and the second electrode 22 are an integrated structure.

[0075] The first limiting portion 32 is disposed around the first electrode 21, and the second limiting portion 33 is disposed around the second electrode 22. For example, both the first limiting portion 32 and the second limiting portion 33 are annular structures. A portion of the first limiting portion 32 is located between the first electrode 21 and the second electrode 22, and similarly, a portion of the second limiting portion 33 is located between the first electrode 21 and the second electrode 22.

[0076] In the embodiment of the present application, the first limiting portion 32 and the second limiting portion 33 located between the first electrode 21 and the second electrode 22 are configured as an integrated structure. Therefore, during the manufacturing process, the first limiting portion 32 and the second limiting portion 33 located between the first electrode 21 and the second electrode 22 can be manufactured and formed in the same process, thereby simplifying the manufacturing process and improving production efficiency. For example, the first limiting portion 32 and the second limiting portion 33 are made of the same material and can be simultaneously manufactured and formed by methods such as chemical vapor deposition.

[0077] The height of the first limiting portion 32 located between the first electrode 21 and the second electrode 22 gradually increases in the direction away from the first electrode 21, while the height of the second limiting portion 33 located between the first electrode 21 and the second electrode 22 gradually decreases in the direction away from the first electrode 21. Therefore, the height of the integrated structure composed of the first limiting portion 32 and the second limiting portion 33 decreases on both sides from the center position between the first electrode 21 and the second electrode 22. The cross-sectional shape of the first limiting portion 32 located on the side of the first electrode 21 away from the second electrode 22 and the second limiting portion 33 located on the side of the second electrode 22 away from the first electrode 21 resembles a right triangle.

[0078] In some embodiments, at least one of the first limiting portion 32 and the second limiting portion 33 located between the first electrode 21 and the second electrode 22 comprises an insulating material.

[0079] The first and second limiting portions 32, 33 located between the first and second electrodes 21, 22 not only protect the first and second electrodes 21, 22 and improve the bonding effect of the light-emitting chip, but also isolate the first and second electrodes 21, 22. On this basis, in the embodiment of the present application, at least one of the first and second limiting portions 32, 33 located between the first and second electrodes 21, 22 is provided with an insulating material, thereby reducing the risk of a short circuit between the first and second electrodes 21, 22.

[0080] In some embodiments, see Figure 7 The orthographic projections of the first limiting portion 32 and the second limiting portion 33 on the epitaxial layer 1 together form a ring structure O, and the orthographic projections of the first electrode 21 and the second electrode 22 on the epitaxial layer 1 are both located within the ring structure O. Figure 7In FIG, the ring structure O is shown in dotted form.

[0081] The first limiting portion 32 and the second limiting portion 33 can be combined to form a closed annular structure O. The first electrode 21 and the second electrode 22 are both located within the annular structure O. This design can simultaneously protect the first electrode 21 and the second electrode 22, thereby improving the reliability of the light-emitting chip. During the manufacturing process, the first limiting portion 32 and the second limiting portion 33 located within the annular structure O can be formed integrally, or the first limiting portion 32 and the second limiting portion 33 located between the first electrode 21 and the second electrode 22 can be formed integrally, thereby further simplifying the manufacturing process.

[0082] In some embodiments, the distance L between the outer contour of the orthographic projection of either the first electrode 21 or the second electrode 22 on the epitaxial layer 1 and the inner ring of the ring structure O in the first direction X is not less than 3 μm, and the second electrode 22 is located on one side of the first electrode 21 in the first direction X. Exemplarily, the first direction X is perpendicular to the thickness direction Y.

[0083] During the transfer process, a predetermined distance exists between the light-emitting chip and the circuit substrate, and the light-emitting chip is exposed to laser light and falls onto the circuit substrate. This process typically results in a certain degree of error, causing the light-emitting chip to shift in the first direction X. If the annular structure O is too close to the first electrode 21 or the second electrode 22, the first limiting portion 32 or the second limiting portion 33 may be transferred to the top of the conductive structure on the circuit substrate. However, because the first limiting portion 32 and the second limiting portion 33 protrude beyond the first electrode 21 and the second electrode 22, it is easy for at least one of the first electrode 21 and the second electrode 22 to lose contact with the conductive structure.

[0084] In order to avoid the risk of such a problem, in the embodiment of the present application, the first electrode 21 and the second electrode 22 are spaced apart from the ring structure O, thereby allowing a certain offset margin during the transfer of the light-emitting chip and improving the yield rate.

[0085] In some embodiments, as Figure 4 As shown, the maximum height H of the portion of the limiting component 3 protruding from the first electrode 21 in the thickness direction Y is no more than 2 μm.

[0086] The protruding portion of the stopper component 3 can form a pointed end 31, which can more easily penetrate deep into the soft rubber layer 41, thereby helping the light-emitting chip to more easily approach the circuit substrate 4. However, if the protruding height of the stopper component 3 is too large, even if the stopper component 3 penetrates deep into the soft rubber layer 41, it will not be possible to achieve contact between the light-emitting chip and the conductive structure on the circuit substrate 4. Therefore, it is necessary to limit the protruding height of the stopper component to enable it to better help the light-emitting chip approach the circuit substrate 4.

[0087] Second, see Figure 8 The embodiment of the present application provides a display device, comprising a light-emitting chip according to any of the aforementioned embodiments. The presence of the limiter group can play a supporting role and reduce the risk of damage to the first electrode due to compression.

[0088] It should be noted that the display device provided in the embodiment of the present application has the beneficial effects of the light-emitting chip provided in the embodiment of the present application. For details, please refer to the specific description of the light-emitting chip in the above embodiments, which will not be repeated in this embodiment.

[0089] Thirdly, please refer to Figure 9 10 , an embodiment of the present application provides a chip transfer method, including:

[0090] S100: a plurality of light-emitting chips are arranged on one side of the substrate to be transferred, and the electrode layer is located on the side of the epitaxial layer away from the substrate to be transferred.

[0091] In step S100, refer to Figure 10a The substrate 5 to be transferred can be a growth substrate for a light-emitting chip, which can be any of the light-emitting chips described in any of the aforementioned embodiments. The electrode layer 2 is located on one side of the epitaxial layer 1 and can include only the first electrode 21 or both the first electrode 21 and the second electrode 22. The embodiments of this application will be described below using the example of the electrode layer 2 including both the first electrode 21 and the second electrode 22.

[0092] S110: Disposing a plurality of first conductive portions and a soft adhesive layer on one side of the target substrate, wherein at least a portion of the soft adhesive layer is disposed around the outer periphery of the first conductive portion, and the hardness of the soft adhesive layer is less than that of the limiting component.

[0093] In step S110, refer to Figure 10b The target substrate is a circuit substrate 4, wherein the first conductive portion 42 is electrically connected to the first electrode. The circuit substrate 4 controls the light-emitting chip to emit light or extinguish light through the first conductive portion 42. For example, in addition to the first conductive portion 42, the circuit substrate 4 further includes a second conductive portion 43, which is electrically connected to the second electrode.

[0094] The soft adhesive layer 41 is used to receive the dropped light-emitting chip. The soft adhesive layer 41 includes a soft adhesive layer 41. During the subsequent transfer process, the limiting component in the light-emitting chip needs to be inserted into the soft adhesive layer 41. To ensure that the limiting component can enter the soft adhesive layer 41, the hardness of the soft adhesive layer 41 is set to be less than the hardness of the limiting component in the embodiment of the application.

[0095] S120: The substrate to be transferred and the target substrate are arranged opposite to each other and spaced apart, and the light-emitting chip is dropped onto the target substrate, with the tip portion embedded in the soft adhesive layer, and the first electrode is in contact with and connected to the first conductive portion.

[0096] In step S120, refer to Figure 10c The tip portion 31 protrudes from the first electrode 21 and the second electrode 22. Therefore, during the laser transfer process, the tip portion 31 will be embedded into the soft glue layer 41 above the circuit substrate 4 before the first electrode 21 and the second electrode 22. Since the tip portion 31 itself has a relatively sharp structure, it can more easily enter a deeper position in the soft glue layer 41, thereby driving the light-emitting chip close to the circuit substrate 4, and then achieving bonding between the light-emitting chip and the circuit substrate 4 without requiring large pressure, thereby improving the bonding yield.

[0097] In some embodiments, as shown in FIG10 b , in the thickness direction Y of the target substrate, the height of the soft adhesive layer 41 is smaller than the height of the first conductive portion 42 , and the height difference ΔH therebetween is no greater than 2 μm.

[0098] If the soft adhesive layer 41 is too high, bonding between the light-emitting chip and the circuit substrate 4 will be difficult. Therefore, in this embodiment, the height of the soft adhesive layer 41 is set to be less than the height of the first conductive portion 42 to reduce the risk of this problem. If the height of the soft adhesive layer 41 is too low, its cushioning effect on the light-emitting chip will be insufficient, which may easily cause the light-emitting chip to malfunction. Therefore, in this embodiment, the height difference ΔH between the soft adhesive layer 41 and the first conductive portion 42 is set to no more than 2μm.

[0099] Although the embodiments disclosed in this application are as described above, the contents described are merely embodiments adopted to facilitate understanding of this application and are not intended to limit the present invention. Any person skilled in the art to which this application belongs may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application. However, the scope of protection of this application shall still be based on the scope defined by the appended claims.

[0100] The above description is only a specific embodiment of the present application. Those skilled in the art will clearly understand that for the convenience and brevity of description, the replacement of other connection methods described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the scope of protection of the present application is not limited to this. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the scope of protection of this application.

Claims

1. A light-emitting chip, characterized in that: include: epitaxial layer; an electrode layer, disposed on a first side in a thickness direction of the epitaxial layer, the electrode layer comprising a first electrode; a limiting component disposed on the first side of the epitaxial layer, wherein an orthographic projection of the limiting component on the epitaxial layer is offset from an orthographic projection of the first electrode on the epitaxial layer, at least a portion of the limiting component is distributed around a circumference of the electrode layer, and in a direction away from the epitaxial layer, the limiting component at least partially protrudes beyond the first electrode; In the direction perpendicular to the thickness direction, the height of the limiting component in the thickness direction tends to change, so as to form a tip portion protruding from the first electrode; in the direction away from the electrode layer, the height of at least part of the limiting component in the thickness direction tends to gradually increase, so as to guide the electrode layer close to the circuit substrate for bonding; The circuit substrate has multiple conductive parts and a soft rubber layer, at least part of the soft rubber layer surrounds the outer peripheral side of the conductive part, and the hardness of the soft rubber layer is less than that of the limiting component. When the light-emitting chip falls onto the circuit substrate, the tip is embedded in the soft rubber layer.

2. The light-emitting chip according to claim 1, wherein: The limiting assembly includes a first limiting portion distributed around the circumference of the first electrode, and the height of the first limiting portion in the thickness direction tends to gradually increase in a direction away from the first electrode.

3. The light-emitting chip according to claim 2, characterized in that: In a direction away from the first electrode, the height of the first limiting portion in the thickness direction increases gradually or linearly.

4. The light-emitting chip according to claim 2, wherein: The first limiting portions are symmetrically distributed around the first electrode.

5. The light-emitting chip according to claim 2, wherein: The first limiting portion includes a plurality of microtube structures; the plurality of microtube structures are nested multilayer structures around the first electrode, and the heights of different microtube structures in the thickness direction tend to gradually increase in the direction away from the first electrode.

6. The light-emitting chip according to claim 5, characterized in that: The diameter of the micro-tube structure decreases as the height of the micro-tube structure in the thickness direction increases.

7. The light-emitting chip according to claim 2, characterized in that: The electrode layer further includes a second electrode, and an orthographic projection of the limiting component on the epitaxial layer and an orthographic projection of the second electrode on the epitaxial layer are staggered and distributed; The limiting assembly includes a second limiting portion distributed around the circumference of the second electrode, and the height of the second limiting portion in the thickness direction tends to gradually increase in a direction away from the second electrode.

8. The light-emitting chip according to claim 7, characterized in that: The first limiting portion and the second limiting portion located between the first electrode and the second electrode are an integrated structure.

9. The light-emitting chip according to claim 8, characterized in that: At least one of the first limiting portion and the second limiting portion located between the first electrode and the second electrode comprises an insulating material.

10. The light-emitting chip according to claim 7, characterized in that: The orthographic projections of the first limiting portion and the second limiting portion on the epitaxial layer together enclose a ring structure, and the orthographic projections of the first electrode and the second electrode on the epitaxial layer are both located within the ring structure.

11. The light-emitting chip according to claim 10, characterized in that: The distance between the outer contour of the orthographic projection of either the first electrode or the second electrode on the epitaxial layer and the inner ring of the annular structure in the first direction is not less than 3 μm, and the second electrode is located on one side of the first electrode in the first direction.

12. The light-emitting chip according to claim 1, wherein: The maximum height of the portion of the limiting component protruding from the first electrode in the thickness direction is no more than 2 μm.

13. A display device, characterized in that: The light-emitting chip comprises the light-emitting chip according to any one of claims 1 to 12.

14. A chip transfer method, characterized in that: include: A plurality of light-emitting chips are arranged on one side of the substrate to be transferred, wherein the light-emitting chips are the light-emitting chips according to any one of claims 1 to 12, and the electrode layer is located on a side of the epitaxial layer away from the substrate to be transferred; A plurality of first conductive portions and a soft adhesive layer are provided on one side of the target substrate, wherein at least a portion of the soft adhesive layer surrounds the outer periphery of the first conductive portion, and the hardness of the soft adhesive layer is less than that of the limiting component; The substrate to be transferred and the target substrate are arranged opposite to each other and spaced apart, and the light-emitting chip is dropped onto the target substrate, the tip portion is embedded in the soft glue layer, and the first electrode is in contact with and connected to the first conductive portion.

15. The transfer method according to claim 14, characterized in that In the thickness direction of the target substrate, the height of the soft adhesive layer is smaller than the height of the first conductive portion, and the height difference between the soft adhesive layer and the first conductive portion is no more than 2 μm.

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