Chip transfer assembly and manufacturing method thereof, chip transfer method and display backplane

Abstract

The present invention relates to a chip transfer component and a manufacturing method thereof, a chip transfer method and a display backplane. The chip transfer component includes a transfer substrate on which a chip adhesive is arranged, and the adhesive layer of the chip adhesive can be bonded to a growth substrate, and a micro LED chip is transferred from the growth substrate to the transfer substrate. A portion of the sacrificial layer of the chip adhesive can be dissolved and removed by the target, and the remaining portion is used as a support to reduce the adhesion strength between the micro LED chip and the transfer substrate, so that when picking up the micro LED chip from the transfer substrate, it is no longer necessary to perform a debonding treatment on the adhesive layer on the transfer substrate by light or heat, which simplifies the transfer step of the micro LED chip, improves the convenience and transfer efficiency of the micro LED chip transfer, shortens the production cycle of the display backplane and the display device to a certain extent, and reduces the production cost.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and in particular to a chip transfer component and a manufacturing method thereof, a chip transfer method and a display backplane. Background Art

[0002] At present, a key technology facing micro-LED (Light Emitting Diode) is to transfer micro-LED chips to the display backplane through mass transfer. In related technologies, a removable adhesive layer is generally set on the first temporary substrate, and the micro-LED chip is transferred from the growth substrate to the first temporary substrate through the removable adhesive layer by adhesion, and then the second temporary substrate is used to transfer the micro-LED chip from the first temporary substrate to the display backplane. In this process, because the adhesive layer on the first temporary substrate has a strong adhesion to the micro-LED chip, the adhesive layer on the first temporary substrate needs to be debonded by light or heat to achieve the transfer of the micro-LED chip to the second substrate. The process of using this LED chip transfer method is relatively complicated and the transfer efficiency is low.

[0003] Therefore, how to achieve convenient and efficient transfer of LED chips is an urgent problem to be solved. Summary of the invention

[0004] In view of the deficiencies of the above-mentioned related technologies, the purpose of the present application is to provide a chip transfer component and its manufacturing method, a chip transfer method and a display backplane, aiming to solve the problem of complex and low efficiency of the transfer process of LED chips in the related technologies.

[0005] A chip transfer assembly, comprising:

[0006] A transfer substrate, and a plurality of groups of chip adhesives disposed on one side of the transfer substrate, wherein the positions of the plurality of groups of chip adhesives on the transfer substrate correspond to the positions of the plurality of micro LED chips to be transferred on the growth substrate, and one group of chip adhesives corresponds to one micro LED chip;

[0007] The chip bonding member includes an adhesive layer and a sacrificial layer arranged in sequence from top to bottom on a transfer substrate, wherein:

[0008] The adhesive layer is used to bond with the first protective layer on the corresponding micro LED chip when the transfer substrate is attached to the growth substrate, so as to remove the micro LED chip from the growth substrate;

[0009] After the micro LED chip is transferred from the growth substrate to the adhesion layer, a portion of the sacrificial layer reacts with the target solution and is dissolved and removed, and the remaining portion serves as a support body for supporting the adhesion layer on the transfer substrate. The support body is subjected to tension during the process of picking up the micro LED chip on the adhesion layer, and falls off from the transfer substrate together with the micro LED chip and the adhesion layer; the first protective layer and the adhesion layer do not react with the target solution.

[0010] In the above-mentioned chip transfer component, the adhesive layer of the chip adhesive on the transfer substrate can be bonded with the growth substrate to transfer the micro LED chip from the growth substrate to the transfer substrate. A portion of the sacrificial layer of the chip adhesive can be dissolved and removed by the target, and the remaining portion of the sacrificial layer serves as a support body to reduce the adhesion strength between the micro LED chip and the transfer substrate. Therefore, when the micro LED chip is picked up from the transfer substrate, the support body of the picked up micro LED chip is subjected to tension and falls off from the transfer substrate together with the micro LED chip and the adhesive layer, thereby omitting the step of debonding the adhesive layer on the transfer substrate by light or heat, simplifying the micro LED chip transfer process and improving the convenience and efficiency of micro LED chip transfer.

[0011] Based on the same inventive concept, the present application also provides a method for manufacturing the above-mentioned chip transfer assembly, comprising:

[0012] A sacrificial layer and an adhesive layer are sequentially arranged from bottom to top on one side of the transfer substrate;

[0013] According to the position distribution of the multiple micro LED chips to be transferred on the growth substrate, a portion of the sacrificial layer and the adhesion layer is removed, and the remaining portions of the sacrificial layer and the adhesion layer form multiple groups of chip adhesives, and a group of chip adhesives corresponds to one micro LED chip.

[0014] The manufacturing method of the chip transfer component is simple, fast and low-cost. When the prepared chip transfer component is used for chip transfer, the step of debonding the adhesive layer on the transfer substrate by light or heat can be omitted, thereby simplifying the transfer steps and improving the transfer efficiency.

[0015] Based on the same inventive concept, the present application also provides a micro LED chip transfer method, comprising:

[0016] On the growth substrate on which the micro LED chips are grown, a first protective layer is formed to cover each micro LED chip, and the first protective layers of each micro LED chip are separated from each other;

[0017] Laying the side of the growth substrate on which the micro LED chips are grown to the side of the transfer substrate provided with multiple sets of chip adhesives in the chip transfer assembly as shown above, so that the first protective layer of each micro LED chip is bonded to the adhesive layer of the corresponding chip adhesive, so as to transfer each micro LED chip to its corresponding adhesive layer;

[0018] The target solution is used to partially dissolve the sacrificial layer of each plurality of chip adhesives, and the remaining sacrificial layer is used as a support for supporting the adhesive layer on the transfer substrate, and the first protective layer and the adhesive layer do not react with the target solution;

[0019] Pick up the micro LED chip from the adhesive layer. During the picking process, the support body of the picked up micro LED chip is subjected to tension and falls off from the transfer substrate along with the micro LED chip and the adhesive layer.

[0020] Removing the first protective layer of the picked-up micro LED chip, the adhesive layer falls off together with the first protective layer;

[0021] The picked-up micro LED chip is transferred to the die-bonding area of ​​the display backplane body.

[0022] In the above-mentioned micro LED chip transfer method, after the micro LED chip is transferred from the growth substrate to the transfer substrate, the target solution can be directly used to dissolve and remove a portion of the sacrificial layer on the transfer substrate, and the remaining portion is used as a support body to reduce the adhesion strength between the micro LED chip and the transfer substrate. In this way, when the micro LED chip is picked up from the transfer substrate, the support body of the picked up micro LED chip is subjected to tension and falls off from the transfer substrate together with the micro LED chip and the adhesion layer. It is no longer necessary to debond the adhesion layer on the transfer substrate by light or heat, which simplifies the micro LED chip transfer steps and improves the convenience and efficiency of micro LED chip transfer.

[0023] Based on the same inventive concept, the present application also provides a display backplane, which includes a display backplane main body, on which a plurality of solid crystal areas are arranged; the display backplane also includes a plurality of micro LED chips, and the plurality of micro LED chips are transferred to the solid crystal areas through the micro LED chip transfer method shown above to complete bonding.

[0024] Due to the adoption of a more convenient and efficient micro-LED chip transfer method, the production of display backplanes has also become more convenient and efficient, thereby shortening the system cycle of display versions to a certain extent and reducing the production cost of display backplanes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of a chip transfer assembly provided in Embodiment 1 of the present invention Figure 1 ;

[0026] Figure 2 for Figure 1 A support column formed after a portion of the sacrificial layer is removed;

[0027] Figure 3-1 Schematic diagram of a chip transfer assembly provided in Embodiment 1 of the present invention Figure 2 ;

[0028] Figure 3-2 for Figure 3-1 A support column formed after a portion of the sacrificial layer is removed;

[0029] Figure 4-1 Schematic diagram 3 of the chip transfer assembly provided in the first embodiment of the present invention;

[0030] Figure 4-2 for Figure 4-1 A support column formed after a portion of the sacrificial layer is removed;

[0031] Figure 4-3 Schematic diagram 4 of a chip transfer assembly provided in Embodiment 1 of the present invention;

[0032] Figure 4-4 for Figure 4-3 A support column formed after a portion of the sacrificial layer is removed;

[0033] Figure 5-1 Schematic diagram 5 of a chip transfer assembly provided in Embodiment 1 of the present invention;

[0034] Figure 5-2 for Figure 5-1 A support column formed after a portion of the sacrificial layer is removed;

[0035] Figure 5-3 Schematic diagram 6 of a chip transfer assembly provided in Embodiment 1 of the present invention;

[0036] Figure 5-4 for Figure 5-3 A support column formed after a portion of the sacrificial layer is removed;

[0037] Figure 5-5 Schematic diagram 6 of a chip transfer assembly provided in Embodiment 1 of the present invention;

[0038] Figure 5-6 for Figure 5-5 A support column formed after a portion of the sacrificial layer is removed;

[0039] Figure 5-7 Schematic diagram of a chip transfer assembly provided in Embodiment 1 of the present invention Figure 7 ;

[0040] Figure 5-8 for Figure 5-7A support column formed after a portion of the sacrificial layer is removed;

[0041] Figure 6-1 Schematic diagram of a chip transfer assembly provided in Embodiment 1 of the present invention Figure 8 ;

[0042] Figure 6-2 for Figure 6-1 A support column formed after a portion of the sacrificial layer is removed;

[0043] Figure 6-3 Schematic diagram of a chip transfer assembly provided in Embodiment 1 of the present invention Figure 9 ;

[0044] Figure 6-4 for Figure 6-3 A support column formed after a portion of the sacrificial layer is removed;

[0045] Figure 7 A schematic diagram of a process flow of a chip transfer assembly manufacturing method provided in Embodiment 2 of the present invention;

[0046] Figure 8 Schematic diagram of the chip transfer assembly manufacturing process provided in the second embodiment of the present invention Figure 1 ;

[0047] Fig. 9 Schematic diagram of the chip transfer assembly manufacturing process provided in the second embodiment of the present invention Figure 2 ;

[0048] Fig.10 Schematic diagram 3 of the chip transfer assembly manufacturing process provided in the second embodiment of the present invention;

[0049] Fig.11 Schematic diagram 4 of the chip transfer assembly manufacturing process provided in the second embodiment of the present invention;

[0050] Figure 12-1 A schematic diagram of a process flow of a micro LED chip transfer method provided in Embodiment 3 of the present invention;

[0051] Figure 12-2 A schematic diagram of a micro LED chip transfer process provided in Embodiment 3 of the present invention;

[0052] Description of reference numerals:

[0053] 1-transfer substrate, 2-sacrificial layer, 3-adhesion layer, 4-barrier layer, 5-peeling layer, 6-mask, 7-growth substrate, 81-epitaxial layer, 82-electrode, 83-first protective layer, 9-pick-up substrate, 91-pick-up protrusion, 10-backplane base, 11-backplane film layer. DETAILED DESCRIPTION

[0054] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly and comprehensively understood.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0056] In the related art, when the micro-LED chip is transferred from the first temporary substrate, since the adhesive layer on the first temporary substrate has a strong adhesion to the micro-LED chip, the adhesive layer on the first temporary substrate needs to be debonded by light or heat in order to transfer the micro-LED chip. This micro-LED chip transfer method has relatively complicated steps and low transfer efficiency, resulting in a long production cycle and high cost for the display backplane and display device.

[0057] Based on this, the present application hopes to provide a solution that can solve the above-mentioned technical problems, the details of which will be described in the subsequent embodiments.

[0058] Embodiment 1:

[0059] The chip transfer assembly provided in this embodiment includes: a transfer substrate, and a plurality of groups of chip adhesives disposed on one side of the transfer substrate, the position distribution of the plurality of groups of chip adhesives on the transfer substrate corresponds to the position distribution of the plurality of micro LED chips to be transferred on the growth substrate, a group of chip adhesives corresponds to one micro LED chip, and a group of chip adhesives includes at least one chip adhesive, wherein:

[0060] The chip bonding member includes an adhesive layer and a sacrificial layer arranged in sequence from top to bottom on a transfer substrate, wherein:

[0061] The adhesive layer is used to bond with the first protective layer on the micro LED chip corresponding to the position when the transfer substrate is attached to the side of the growth substrate on which the micro LED chip is grown, so as to remove the micro LED chip from the growth substrate;

[0062] The sacrificial layer is configured to be a material that can react with the target solution and be dissolved, and the first protective layer on the micro LED chip is configured not to react with the target solution, so as not to be dissolved by the target solution. After the micro LED chip is transferred from the growth substrate to the adhesive layer on the transfer substrate, the target solution can be used to partially dissolve the sacrificial layer between the adhesive layer and the transfer substrate, so that the sacrificial layer is partially removed, and the remaining part of the sacrificial layer serves as a support body that supports the adhesive layer (and the micro LED chip on the adhesive layer) on the transfer substrate. The support body is subjected to tension during the process of picking up the micro LED chip on the adhesive layer, and falls off the transfer substrate together with the micro LED chip and the adhesive layer. Therefore, it is no longer necessary to debond the adhesive layer on the transfer substrate through a complex debonding process, thereby simplifying the micro LED chip transfer process and improving the convenience and efficiency of micro LED chip transfer.

[0063] In this embodiment, there is no limitation on the material of the transfer substrate. For example, in one example, the material of the transfer substrate can be, but is not limited to, any one of glass, sapphire, quartz and silicon.

[0064] In this embodiment, the material of the sacrificial layer and the composition of the target solution can be set accordingly. For example, in some examples, the material of the sacrificial layer can be, but not limited to, a metal that can react with acid and be etched, such as Al, Mo, Cu, etc. At this time, the sacrificial layer can be formed by, but not limited to, a metal film-forming method, and correspondingly, the target solution can be an acidic solution. For another example, in some other examples, the material of the sacrificial layer can be, but not limited to, an alkaline organic substance that can react with acid, such as, but not limited to, polyimide PI or PMMA (Poly Methyl Meth Acrylate, polymethyl methacrylate) as the main chain structure, and the side chain has an amine group -NH2 and other alkaline groups.

[0065] In this embodiment, the specific material of the adhesive layer of the chip adhesive on the transfer substrate can also be flexibly selected, and it does not react with the above-mentioned target solution. The viscosity of the adhesive layer is sufficient to reliably adhere the corresponding micro LED chip when it is attached to the side of the growth substrate on which multiple micro LED chips are grown. Optionally, when the micro LED chip is peeled off from the growth substrate and transferred to the transfer substrate, LLO (Laser Lift Off) can also be used but is not limited to ensure that the micro LED chip is smoothly peeled off from the growth substrate.

[0066] The material of the growth substrate in this embodiment is a semiconductor material on which the epitaxial layer of the micro LED chip can be grown. For example, the material of the growth substrate can be but is not limited to sapphire, silicon carbide, silicon, gallium arsenide, or other semiconductor materials, which are not limited here.

[0067] The micro LED chip generated on the growth substrate in this embodiment includes an epitaxial layer and an electrode. This embodiment does not limit the specific structure of the epitaxial layer of the micro LED chip. In one example, the epitaxial layer of the micro LED chip may include an N-type semiconductor, a P-type semiconductor, and an active layer located between the N-type semiconductor and the P-type semiconductor. The active layer may include a quantum well layer and may also include other structures. In other examples, optionally, the epitaxial layer may also include at least one of a reflective layer and a passivation layer. The material and shape of the electrode in this embodiment are also not limited. For example, in one example, the material of the electrode may include but is not limited to at least one of Cr, Ni, Al, Ti, Au, Pt, W, Pb, Rh, Sn, Cu, and Ag.

[0068] It should be understood that the micro LED chip in this embodiment may include but is not limited to at least one of a micro-LED chip and a mini-LED chip. For example, in one example, the micro LED chip may be a micro-LED chip; in another example, the micro LED chip may be a mini-LED chip.

[0069] It should be understood that the micro LED chip in this embodiment may include but is not limited to at least one of a flip-chip LED chip and a face-mounted LED chip. For example, in one example, the micro LED chip may be a flip-chip LED chip; in another example, the micro LED chip may be a face-mounted LED chip.

[0070] In this embodiment, after the micro LED chip is grown on the transfer substrate, a first protective layer covering the micro LED chip is formed. As described above, the material of the first protective layer does not react with the target solution, and the first protective layer covers all surfaces of the micro LED chip except the surface in contact with the growth substrate, so as to provide reliable protection for the LED chip and prevent the micro LED chip from being damaged by contact with the target solution.

[0071] Optionally, in some examples of this embodiment, in order to prevent the sacrificial layer from being embedded in the adhesion layer under pressure, especially when a portion of the sacrificial layer is dissolved and removed, and the support column formed by the remaining portion is embedded in the adhesion layer under pressure, the chip adhesive may further include a barrier layer disposed between the adhesion layer and the sacrificial layer, the barrier layer having a higher hardness than the adhesion layer, and the barrier layer does not react with the target solution. The material of the barrier layer can be flexibly selected according to the specific application scenario. For example, when the target solution is an acidic solution, the barrier layer may be, but is not limited to, SiOx or SiNx. Since the hardness of the barrier layer is higher than that of the adhesion layer, the sacrificial layer is more difficult to be embedded in the barrier layer under pressure compared to the adhesion layer, thereby ensuring that the subsequent micro LED chip can be smoothly picked up from the transfer substrate.

[0072] As shown above, optionally, in some examples of this embodiment, when the target solution may be an acidic solution, the sacrificial layer may be an alkaline organic glue layer that can react with the acidic solution, and the sacrificial layer may be directly disposed on the transfer substrate;

[0073] Optionally, in some other examples of this embodiment, the sacrificial layer may be a metal film layer that can react with an acidic solution. Since the adhesion between the metal film layer and the transfer substrate is strong, in order to further ensure that the subsequent micro LED chip can be smoothly picked up and transferred from the transfer substrate, the chip adhesive also includes a peeling layer arranged between the sacrificial layer and the transfer substrate. The peeling layer does not react with the target solution, and its material can be flexibly selected according to the specific application scenario. And the adhesion between the sacrificial layer and the peeling layer is less than the adhesion between the sacrificial layer and the transfer substrate when it is directly arranged on the transfer substrate. In some application scenarios of this example, the peeling layer may not be covered in the spacing area between adjacent chip adhesives. In other application scenarios of this example, the spacing area between adjacent chip adhesives may also be covered by the peeling layer.

[0074] As shown above, in the multiple groups of chip adhesives arranged on the transfer substrate in this embodiment, one group of chip adhesives corresponds to one micro LED chip, and the number of chip adhesives included in one group of chip adhesives can be flexibly set.

[0075] For instance, in one example, a group of chip adhesives may include two chip adhesives, the positions of the two chip adhesives respectively corresponding to the positions of the two electrodes of the micro LED chip, and there is a gap between the two chip adhesives. The setting of the gap facilitates the subsequent dissolution and removal of the sacrificial layer by the target solution, thereby ensuring that the sacrificial layers on both sides corresponding to the area between the two electrodes of the micro LED chip can be dissolved synchronously, thereby avoiding the micro LED chip on the adhesive layer from tilting after dissolution, thereby ensuring stable support for the micro LED chip.

[0076] For another example, in this embodiment, a group of chip adhesives may include only one chip adhesive, and the position of the chip adhesive corresponds to the target area between the two electrodes of the micro LED chip, that is, the middle position of the micro LED chip, so as to ensure a stable support for the micro LED chip. When the sacrificial layer is subsequently dissolved and removed by the target solution, the target solution can dissolve the sacrificial layer from all sides.

[0077] For a better understanding, several specific setting examples are provided below for explanation.

[0078] For an example of a setup, see Figure 1 to Figure 2As shown, a plurality of groups of chip adhesives are arranged on the transfer substrate 1, each group of chip adhesives includes two chip adhesives, and the two chip adhesives are arranged corresponding to the two electrodes of the micro LED chip on the growth substrate. Each chip adhesive includes a sacrificial layer 2 directly arranged on the transfer substrate, and an adhesive layer 3 arranged on the sacrificial layer 2. In this example, the sacrificial layer 2 can be but is not limited to an alkaline organic adhesive layer. After the sacrificial layer 2 reacts with the target solution and a part is removed, the support body formed is shown in FIG. Figure 2 The remaining sacrificial layer 2 can greatly reduce the bonding strength between the sacrificial layer 2 and the transfer substrate 3, so that the sacrificial layer 2 can be separated from the transfer substrate 3 without the need for debonding treatment and can withstand the pulling force applied when picking up the micro LED chip.

[0079] For another example of a setup, see Figure 3-1 to Figure 3-2 As shown, it is Figure 1 to Figure 2 Compared with the example shown, the main difference is that each group of chip bonding parts only includes one chip bonding part, and this one chip bonding part corresponds to the middle area between the two electrodes of the micro LED chip on the growth substrate. Figure 3-1 After the sacrificial layer 2 in the reaction with the target solution is partially removed, the support body formed is shown in FIG. Figure 3-2 The remaining sacrificial layer 2 can greatly reduce the bonding strength between the sacrificial layer 2 and the transfer substrate 3, so that the sacrificial layer 2 can be separated from the transfer substrate 3 without the need for debonding treatment and can withstand the pulling force applied when picking up the micro LED chip.

[0080] For another example of a setup, see Figure 4-1 to Figure 4-2 As shown, it is Figure 1 to Figure 2 Compared with the example shown, the main difference is that a barrier layer 4 is arranged between the sacrificial layer 2 and the adhesion layer 3. Figure 4-1 After the sacrificial layer 2 in the reaction with the target solution is partially removed, the support body formed is shown in FIG. Figure 4-2 As for the remaining sacrificial layer 2, since the hardness of the barrier layer 4 is higher than that of the adhesion layer 3, it is possible to prevent the sacrificial layer 2 from being embedded in the adhesion layer 3 due to the increased pressure caused by the reduced contact area after a part of the sacrificial layer 2 is removed. Figure 4-3 and Figure 4-4 The die attach assembly shown, with Figure 4-1 and Figure 4-2 Compared with the example shown, the main difference is that each group of chip bonding parts only includes one chip bonding part, and this one chip bonding part corresponds to the middle area between the two electrodes of the micro LED chip on the growth substrate. Figure 4-3 After the sacrificial layer 2 in the reaction with the target solution is partially removed, the support body formed is shown in FIG. Figure 4-4 The remaining sacrificial layer 2.

[0081] For another example of a setup, see Figure 5-1 to Figure 5-2 As shown, it is Figure 1 to Figure 2 Compared with the example shown, the main difference is that a peeling layer 5 is provided between the sacrificial layer 2 and the transfer substrate 3. The sacrificial layer 2 in this example can be, but is not limited to, a metal film layer. The adhesion between the sacrificial layer 2 and the peeling layer 5 is less than the adhesion between the sacrificial layer 2 and the transfer substrate 3 when the sacrificial layer 2 is directly provided on the transfer substrate 3, so that the sacrificial layer 2 can be smoothly separated from the peeling layer 5 later. Figure 5-1 After the sacrificial layer 2 in the reaction with the target solution is partially removed, the support body formed is shown in FIG. Figure 5-2 The remaining sacrificial layer 2. Figure 5-3 and Figure 5-4 The die attach assembly shown, with Figure 5-1 and Figure 5-2 The main difference compared to the example shown is that the release layer 5 also covers the spacing areas between the die attach components. Figure 5-5 and Figure 5-6 The die attach assembly shown, with Figure 5-1 and Figure 5-2 Compared with the example shown, the main difference is that each group of chip bonding parts only includes one chip bonding part, and this one chip bonding part corresponds to the middle area between the two electrodes of the micro LED chip on the growth substrate. Figure 5-7 and Figure 5-8 The die attach assembly shown, with Figure 5-3 and Figure 5-4 Compared with the example shown, the main difference is that each group of chip bonding parts only includes one chip bonding part, and this chip bonding part corresponds to the middle area between the two electrodes of the micro LED chip on the growth substrate.

[0082] For another example of a setup, see Figure 6-1 to Figure 6-2 As shown, it is Figure 1 to Figure 2 Compared with the example shown, the main difference is that a release layer 5 is provided between the sacrificial layer 2 and the transfer substrate 3, and a barrier layer 4 is provided between the sacrificial layer 2 and the adhesive layer 3. Figure 6-1 After the sacrificial layer 2 in the reaction with the target solution is partially removed, the support body formed is shown in FIG. Figure 6-2 The remaining sacrificial layer 2. Figure 6-3 and Figure 6-4 The die attach assembly shown, with Figure 6-1 and Figure 6-2 Compared with the example shown, the main difference is that each group of chip bonding parts only includes one chip bonding part, and this one chip bonding part corresponds to the middle area between the two electrodes of the micro LED chip on the growth substrate.

[0083] Based on the above examples, it can be seen that the number of chip adhesives included in a group of chip adhesives in this embodiment, as well as the position distribution of the chip adhesives corresponding to the micro LED chips can be flexibly set and are not limited to the above examples.

[0084] It can be seen that the chip transfer component provided by the embodiment has a transfer substrate on which a plurality of groups of chip bonding components corresponding to the micro LED chips are arranged. The sacrificial layer of the chip bonding component can be reacted with the target solution, and a support column that weakens the bonding strength between the micro LED chip and the transfer substrate can be formed on the transfer substrate, that is, a weakening structure that weakens the bonding strength between the micro LED chip and the transfer substrate is formed, thereby omitting the process step of debonding the adhesive layer on the transfer substrate, making the chip transfer more convenient and efficient.

[0085] Embodiment 2:

[0086] For ease of understanding, this embodiment below illustrates a method for making the chip transfer assembly of the above example. Figure 7 As shown, including but not limited to:

[0087] S701: a sacrificial layer and an adhesive layer are sequentially disposed from bottom to top on one side of the transfer substrate.

[0088] S702: According to the position distribution of the multiple micro LED chips to be transferred on the growth substrate, a portion of the sacrificial layer and the adhesion layer on the transfer substrate is removed, and the remaining portions of the sacrificial layer and the adhesion layer form multiple groups of chip adhesives, and a group of chip adhesives corresponds to one of the micro LED chips.

[0089] In this example, the method of removing a portion of the sacrificial layer and the adhesive layer on the transfer substrate may be, but is not limited to, photolithography, cutting, etc. For ease of understanding, the following is an explanation of the production method in conjunction with an application example. Figure 8 As shown, including:

[0090] S801: A sacrificial layer 2 and an adhesive layer 3 are sequentially formed on a transfer substrate 1, wherein the sacrificial layer 2 may be, but is not limited to, an alkaline organic layer. The sacrificial layer 2 and the adhesive layer 3 in this application example contain a photosensitive material, so that they have photoresist properties, that is, after being irradiated by ultraviolet light, the irradiated part will be washed away by a developer (i.e., a positive photoresist) or after being irradiated by ultraviolet light, the unirradiated part will be washed away by a developer, while the irradiated part will remain (i.e., a negative photoresist); this application example is described below using a positive photoresist as an example.

[0091] S802: Expose and develop the adhesive layer 3 side through a mask plate 6 having a specific pattern (the pattern corresponds to the spacing and distribution of the micro LEDs on the growth substrate), so that a portion of the sacrificial layer 2 and the adhesive layer 3 are washed away.

[0092] S803: After the sacrificial layer 2 and the adhesive layer 3 are washed off, the remaining parts form a plurality of groups of chip adhesives, one group of chip adhesives corresponds to one of the micro LED chips, and one group of chip adhesives includes two chip adhesives. For an example in which a group of chip adhesives includes only one chip adhesive, it is only necessary to adjust the pattern on the mask 6 accordingly, which will not be described in detail.

[0093] Optionally, in some examples, in order to prevent the sacrificial layer from being embedded in the adhesion layer under pressure, especially when a portion of the sacrificial layer is dissolved and removed, and the support column formed by the remaining portion is embedded in the adhesion layer under pressure, the chip adhesive may also include a barrier layer disposed between the adhesion layer and the sacrificial layer, the barrier layer having a higher hardness than the adhesion layer, and the barrier layer does not react with the target solution. The material of the barrier layer can be flexibly selected according to the specific application scenario. For example, when the target solution is an acidic solution, the barrier layer may be, but is not limited to, SiOx or SiNx. Therefore, in this example, the sacrificial layer and the adhesion layer are disposed sequentially from bottom to top on one side of the transfer substrate, and may include, but is not limited to:

[0094] Disposing a sacrificial layer on one side of the transfer substrate;

[0095] A barrier layer is provided on the sacrificial layer, wherein the hardness of the barrier layer is higher than that of the adhesion layer;

[0096] An adhesion layer is provided on the barrier layer, and when the sacrificial layer and a part of the adhesion layer are removed, the corresponding part of the barrier layer is also removed. For ease of understanding, the following is an explanation of the manufacturing method in conjunction with an application example. Fig. 9 As shown, including:

[0097] S901: A sacrificial layer 2, a barrier layer 4 and an adhesion layer 3 are sequentially formed on a transfer substrate 1. The barrier layer 4 in this application example also has a photosensitive material, which enables it to have photoresist properties, that is, after being irradiated by ultraviolet light, the irradiated portion will be washed away by a developer (i.e., positive photoresist) or after being irradiated by ultraviolet light, the unirradiated portion will be washed away by a developer, while the irradiated portion will be retained (i.e., negative photoresist); this application example is described below using positive photoresist as an example.

[0098] S902: Expose and develop the adhesive layer 3 side through a mask plate 6 having a specific pattern (the pattern corresponds to the spacing and distribution of micro LEDs on the growth substrate), so that a portion of the sacrificial layer 2, the barrier layer 4 and the adhesive layer 3 are washed away.

[0099] S903: After the sacrificial layer 2, the barrier layer 4 and the adhesive layer 3 are washed off, the remaining parts form a plurality of groups of chip adhesives, one group of chip adhesives corresponds to one of the micro LED chips, and one group of chip adhesives includes two chip adhesives. For an example in which a group of chip adhesives includes only one chip adhesive, it is only necessary to adjust the pattern on the mask 6 accordingly, which will not be described in detail.

[0100] Optionally, in some other examples of this embodiment, the sacrificial layer may be a metal film layer that can react with an acidic solution. Since the adhesion between the metal film layer and the transfer substrate is strong, in order to further ensure that the subsequent micro LED chip can be smoothly picked up and transferred from the transfer substrate, the chip adhesive also includes a peeling layer arranged between the sacrificial layer and the transfer substrate. The peeling layer does not react with the target solution, and its material can be flexibly selected according to the specific application scenario. And the adhesion between the sacrificial layer and the peeling layer is less than the adhesion between the sacrificial layer and the transfer substrate when it is directly arranged on the transfer substrate. Therefore, in this example, the sacrificial layer and the adhesion layer are arranged in sequence from bottom to top on one side of the transfer substrate, which may include but are not limited to:

[0101] Disposing a peeling layer on one side of the transfer substrate;

[0102] A sacrificial layer is arranged on the peeling layer, and the adhesion between the sacrificial layer and the peeling layer is smaller than the adhesion between the sacrificial layer and the transfer substrate when the sacrificial layer is directly arranged on the transfer substrate;

[0103] An adhesive layer is provided on the sacrificial layer. For ease of understanding, the following is an explanation of the production method in conjunction with an application example. Fig.10 As shown, including:

[0104] S1001: forming a peeling layer 5, a sacrificial layer 2 and an adhesive layer 3 in sequence on a transfer substrate 1. The peeling layer 5 in this application example may contain a photosensitive material, or a photosensitive material may be provided.

[0105] S1002: Expose and develop the adhesive layer 3 side through a mask plate 6 having a specific pattern (the pattern corresponds to the spacing and distribution of micro LEDs on the growth substrate), so that a portion of the sacrificial layer 2 and the adhesive layer 3 are washed away, and the peeling layer 5 may not include the photosensitive material and will not be washed away; of course, the photosensitive material can also be set to wash it away as required.

[0106] S1003: After the sacrificial layer 2 and the adhesive layer 3 are washed off, the remaining parts form a plurality of groups of chip adhesives, one group of chip adhesives corresponds to one of the micro LED chips, and one group of chip adhesives includes two chip adhesives. For an example in which a group of chip adhesives includes only one chip adhesive, it is only necessary to adjust the pattern on the mask 6 accordingly, which will not be described in detail.

[0107] Of course, in some other examples of this embodiment, the barrier layer and the peeling layer can be provided at the same time. For example, an exemplary manufacturing process is shown in FIG. Fig.11 As shown, including:

[0108] S1101 : forming a peeling layer 5 , a sacrificial layer 2 , a barrier layer 4 and an adhesive layer 3 in sequence on a transfer substrate 1 .

[0109] S1102: Exposure and development are performed on the side of the adhesion layer 3 through a mask plate 6 having a specific pattern (the pattern corresponds to the spacing and distribution of micro LEDs on the growth substrate), so that a portion of the sacrificial layer 2, the barrier layer 4 and the adhesion layer 3 are washed away.

[0110] S1103: After the sacrificial layer 2, the barrier layer 4 and the adhesive layer 3 are washed off, the remaining parts form a plurality of groups of chip adhesives, one group of chip adhesives corresponds to one of the micro LED chips, and one group of chip adhesives includes two chip adhesives. For an example in which a group of chip adhesives includes only one chip adhesive, it is only necessary to adjust the pattern on the mask 6 accordingly, which will not be described in detail.

[0111] It can be seen that the number of chip adhesives included in a group of chip adhesives in this embodiment, as well as the position distribution of the chip adhesives corresponding to the micro LED chips, can be flexibly controlled by photolithography or cutting, and are not limited to the above examples.

[0112] Embodiment three:

[0113] For ease of understanding, this embodiment uses the above-mentioned example of the chip transfer component in the chip transfer process as an example to illustrate. Figure 12-1 to Figure 12-2 As shown, the micro LED chip transfer method in this example includes but is not limited to:

[0114] S1201: On the growth substrate on which the micro LED chips are grown, a first protective layer is formed to cover each micro LED chip, and the first protective layers of each micro LED chip are separated from each other. Figure 12-2 As shown in step S1201, a micro LED chip is generated on the growth substrate 7, which includes an epitaxial layer 81 and an electrode 82, and a first protective layer 83 covering each micro LED chip is formed. The first protective layer 83 can be, but is not limited to, a PI protective layer or a PMMA protective layer, and does not react with the acidic target solution.

[0115] S1202: The side of the growth substrate on which the micro LED chip is grown is aligned with the above Fig.11In the obtained chip transfer assembly, the transfer substrate is provided with a plurality of groups of chip adhesives on one side so that the first protective layer of each micro LED chip is bonded to the adhesive layer of the corresponding chip adhesive. Of course, the chip transfer assembly shown in the other figures above can also be selected according to the application scenario. Figure 12-2 As shown in the corresponding step S1201, after lamination, the first protective layer 83 on the micro LED chip is bonded to the adhesive layer of the chip bonding component.

[0116] S1203: Transferring each micro LED chip from the growth substrate to its corresponding adhesive layer.

[0117] In some examples, the micro LED chip on the growth substrate may be peeled off by, but not limited to, LLO (Laser Lift Off), and the micro LED chip may be transferred and fixed on a transfer substrate.

[0118] S1204: forming a second protective layer on the surface of the micro LED chip not covered by the first protective layer (ie, the other surface of the micro LED chip opposite to the surface where the electrode is located), wherein the second protective layer does not react with the target solution.

[0119] It should be understood that step S1204 is an optional step that does not have to be performed. For example, in some application examples, when the material of the surface of the micro LED chip that is not covered by the first protective layer is a material that does not react with the target solution, S1204 may not be performed. For example, when the target solution is an acidic solution, and the material of the other surface of the micro LED chip opposite to the surface where the electrode is located is but not limited to gallium nitride GaN, step S1204 may not be performed. In this application scenario, when the material of the surface of the micro LED chip that is not covered by the first protective layer is a material that reacts with the target solution, step S1204 needs to be performed. In this case, see Figure 12-2 As shown in step S1204 in the figure, a second protective layer 84 is generated. Optionally, in other examples, regardless of whether the material of the surface of the micro LED chip not covered by the first protective layer is a material that reacts with the target solution, the second protective layer is directly formed on the surface of the micro LED chip not covered by the first protective layer.

[0120] S1205: using the target solution to partially dissolve the sacrificial layer of each of the plurality of chip adhesives, and the remaining sacrificial layer serves as a support for supporting the adhesive layer on the transfer substrate.

[0121] See for example Figure 12-2As shown in the corresponding step S1205, assuming that the sacrificial layer 2 is a metal film layer that reacts with the acidic solution, the acidic solution can be used to dissolve a portion of the sacrificial layer 2. And because there is a gap between the two chip bonding parts corresponding to the two electrodes of the micro LED chip, the target solution can flow into the gap and dissolve the sacrificial layers on both sides of the gap synchronously, thereby ensuring the symmetry of the support body obtained on both sides and preventing the micro LED chip from tilting and affecting the subsequent pick-up and bonding.

[0122] S1206: Pick up the micro LED chip from the adhesive layer.

[0123] In this embodiment, when picking up the micro LED chips from the transfer substrate, a single chip can be picked up or a batch of multiple chips can be picked up. When a batch of multiple chips is picked up, the chips can be picked up selectively according to specific application requirements. It should be understood that in this embodiment, when picking up the micro LED chips from the transfer substrate, a pick-up substrate can be used, or a transfer head or other methods can be used. The specific method can be flexibly selected according to specific application requirements. The following uses a pick-up substrate as an example, see Figure 12-2 In the step corresponding to S1206, the pick-up substrate 9 is bonded to the transfer substrate 3. The pick-up substrate 9 has a plurality of patterned pick-up protrusions 91, and the pick-up protrusions 91 have a selectively weakly sticky adhesive layer. After bonding with the transfer substrate 1, the adhesion between the pick-up protrusions 91 and the micro LED chip is greater than the adhesion between the sacrificial layer 2 and the peeling layer 5. The micro LED chip can be transferred by adhesion without debonding the transfer substrate 1. The spacing between the pick-up protrusions 91 can correspond to the pixel spacing on the display backplane (for example, in order to reduce costs, LEDs are manufactured more densely, and the spacing between LEDs needs to be adjusted to be consistent with the pixel spacing of the display backplane).

[0124] S1207: During the picking process, the support body of the picked micro LED chip is subjected to tension, and falls off from the transfer substrate along with the micro LED chip and the adhesive layer, thereby achieving the transfer of the micro LED chip from the transfer substrate to the picking substrate.

[0125] See also Figure 12-2 In the step corresponding to S1207 , the micro LED chip is selectively transferred from the transfer substrate 1 to the pickup substrate 9 .

[0126] S1208: removing the first protective layer of the picked-up micro LED chip, and the adhesive layer falls off together with the first protective layer.

[0127] In this example, a cleaning solution that can dissolve and clean the first protective layer without damaging the micro LED chip can be used. For example, when the first protective layer is a PI protective layer or a PMMA protective layer, the cleaning solution can be a solvent such as N-methylpyrrolidone NMP, but not limited to, and then the electrode is dried. For a form after the first protective layer is cleaned, please refer to the step corresponding to S1208 in Figure 3.

[0128] S1209: Transferring the picked-up micro LED chip to the die bonding area of ​​the display backplane.

[0129] See for example Figure 12-2 In the step corresponding to 1209, the display backplane in this example may be, but not limited to, a display backplane, including a backplane substrate 10 and a backplane film layer 11. The metal Bump material required for binding and welding (for example, but not limited to tin Sn or indium In) may be prepared in advance in the solid crystal area on the backplane film layer 8. The electrodes of the micro LED chip are connected to the Bump by pressure bonding, and then the Bump is heated to melt, thereby welding the electrodes of the micro LED chip. After that, the pick-up substrate 9 is removed, because the pick-up protrusions 91 of the pick-up substrate 9 are weakly sticky to the micro LED chip, and the fixing force of the electrodes of the micro LED chip on the LED after binding is greater than the adhesion force of the pick-up protrusions 91 on the micro LED chip, so that the pick-up substrate 9 does not need to be debonded, and the separation from the pick-up substrate 9 can be completed, thereby completing the transfer of the micro LED chip to the solid crystal area to complete the bonding. The entire process does not require complex debonding process processing, which simplifies the chip transfer process and improves the convenience and efficiency of chip transfer.

[0130] S1210: peeling off the pick-up substrate, a form after peeling off is shown in FIG. Figure 12-2 As shown in the step corresponding to S1210.

[0131] The present embodiment provides a display backplane and a method for manufacturing the display backplane, wherein the display backplane includes a display backplane main body on which a plurality of solid crystal areas are arranged; in the method for manufacturing the display backplane, a transfer method for transferring a micro LED chip on a growth substrate to the solid crystal area to complete bonding may adopt but is not limited to the micro LED chip transfer method exemplified in the above embodiment.

[0132] The present embodiment also provides a display device, which can be used as an electronic device that can display various display backplanes made of micro LED chips, such as various smart mobile terminals, PCs, monitors, electronic billboards, etc., wherein the display backplane of the display device can be but is not limited to being made using the above-mentioned display backplane manufacturing method.

[0133] It should be understood that the process of picking up the micro LED chip from the transfer substrate using the transfer head is similar to the process of using the pickup substrate described above, and will not be described in detail here. In addition, when the micro LED chip is a normal-mounted LED chip, it is only necessary to use the transfer substrate with the weakened structure described above according to the specific application scenario to transfer it once more, so that the electrode portion of the micro LED chip faces the die-bonding area on the display backplane when picking it up. The transfer process is similar, and will not be described in detail here.

[0134] It can be seen that in each of the above application examples, after the micro LED chip is transferred to the transfer substrate as the growth substrate, a portion of the sacrificial layer between the transfer substrate and each micro LED chip is removed, and the unremoved portion serves as a support body for supporting each micro LED chip on the transfer substrate. When the micro LED chip is picked up from the transfer substrate, the support body of the picked up micro LED chip is pulled apart from the transfer substrate, so that the picked up micro LED chip is detached from the transfer substrate. The entire chip transfer process can omit the step of debonding the adhesive layer on the transfer substrate by light or heat, which can simplify the chip transfer process and improve the convenience and efficiency of chip transfer.

[0135] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A chip transfer assembly, characterized in that: include: A transfer substrate, and a plurality of groups of chip adhesives disposed on one side of the transfer substrate, wherein the positions of the plurality of groups of chip adhesives on the transfer substrate correspond to the positions of the plurality of micro LED chips to be transferred on the growth substrate, and one group of the chip adhesives corresponds to one micro LED chip; The chip bonding member includes an adhesive layer and a sacrificial layer arranged sequentially from top to bottom on the transfer substrate, wherein: The adhesive layer is used to bond with the first protective layer on the corresponding micro LED chip when the transfer substrate is attached to the growth substrate, so as to remove the micro LED chip from the growth substrate; After the micro LED chip is transferred from the growth substrate to the adhesion layer, a portion of the sacrificial layer reacts with the target solution and is dissolved and removed, and the remaining portion of the sacrificial layer serves as a support body for supporting the adhesion layer on the transfer substrate. The support body is subjected to tension during the process of picking up the micro LED chip on the adhesion layer, and falls off from the transfer substrate together with the micro LED chip and the adhesion layer; the first protective layer and the adhesion layer do not react with the target solution.

2. The chip transfer assembly according to claim 1, characterized in that: The chip bonding component further includes a barrier layer disposed between the adhesion layer and the sacrificial layer, the barrier layer has a higher hardness than the adhesion layer, and the barrier layer does not react with the target solution.

3. The chip transfer assembly according to claim 1, characterized in that: The target solution is an acidic solution, the sacrificial layer is an alkaline organic glue layer that can react with the acidic solution, and the sacrificial layer is directly disposed on the transfer substrate; or, The sacrificial layer is a metal film layer that can react with the acidic solution. The chip adhesive also includes a peeling layer arranged between the sacrificial layer and the transfer substrate. The peeling layer does not react with the target solution. The adhesion between the sacrificial layer and the peeling layer is smaller than the adhesion between the sacrificial layer and the transfer substrate when the sacrificial layer is directly arranged on the transfer substrate.

4. The chip transfer assembly according to any one of claims 1 to 3, characterized in that: A group of the chip bonding parts includes two chip bonding parts, the positions of the two chip bonding parts respectively correspond to the positions of the two electrodes of the micro LED chip, and there is a gap between the two chip bonding parts; or, A group of the chip bonding parts includes one chip bonding part, and a position of the chip bonding part corresponds to a target area position between two electrodes of the micro LED chip.

5. A method for manufacturing a chip transfer assembly according to any one of claims 1 to 4, characterized in that: include: A sacrificial layer and an adhesive layer are sequentially arranged from bottom to top on one side of the transfer substrate; According to the position distribution of the multiple micro LED chips to be transferred on the growth substrate, the sacrificial layer and a portion of the adhesion layer are removed, and the remaining portions of the sacrificial layer and the adhesion layer constitute the multiple groups of chip adhesives, and one group of the chip adhesives corresponds to one of the micro LED chips.

6. The method for manufacturing a chip transfer assembly according to claim 5, characterized in that: The step of sequentially arranging a sacrificial layer and an adhesive layer from bottom to top on one side of the transfer substrate comprises: Disposing a sacrificial layer on one side of the transfer substrate; Disposing a barrier layer on the sacrificial layer, wherein the barrier layer has a higher hardness than the adhesion layer; providing an adhesive layer on the barrier layer; When removing a portion of the sacrificial layer and the adhesion layer, the method further includes removing a corresponding portion of the barrier layer.

7. The method for manufacturing a chip transfer assembly according to claim 6, characterized in that: When the sacrificial layer is a metal film layer, the step of sequentially arranging the sacrificial layer and the adhesive layer from bottom to top on one side of the transfer substrate comprises: Disposing a peeling layer on one side of the transfer substrate; A sacrificial layer is disposed on the peeling layer, wherein the adhesion between the sacrificial layer and the peeling layer is smaller than the adhesion between the sacrificial layer and the transfer substrate when the sacrificial layer is directly disposed on the transfer substrate; An adhesion layer is disposed on the sacrificial layer.

8. A method for transferring a micro LED chip, characterized in that: include: On the growth substrate on which the micro LED chips are grown, a first protective layer is formed to cover each micro LED chip, wherein the first protective layers of each micro LED chip are separated from each other; Laying the side of the growth substrate on which the micro LED chips are grown to the side of the transfer substrate provided with the plurality of groups of chip adhesives in the chip transfer assembly according to any one of claims 1 to 4, so that the first protective layer of each micro LED chip is bonded to the adhesive layer in the corresponding chip adhesive, so as to transfer each micro LED chip to the corresponding adhesive layer; The target solution is used to partially dissolve the sacrificial layer of each of the plurality of chip adhesives, and the remaining sacrificial layer is used as a support for supporting the adhesive layer on the transfer substrate, and the first protective layer and the adhesive layer do not react with the target solution; Picking up the micro LED chip from the adhesive layer, wherein during the picking up process, the support body of the picked up micro LED chip is subjected to a tensile force and falls off from the transfer substrate along with the micro LED chip and the adhesive layer; Removing the first protective layer of the picked up micro LED chip, and the adhesive layer and the first protective layer fall off together; The picked-up micro LED chip is transferred to the solid crystal area of ​​the display backplane body.

9. The micro LED chip transfer method according to claim 8, wherein: After transferring each of the micro LED chips to the corresponding adhesive layer, before partially dissolving the sacrificial layer of each of the plurality of chip adhesives using the target solution, the method further includes: A second protective layer is formed on the surface of the micro LED chip not covered by the first protective layer, and the second protective layer does not react with the target solution.

10. A display backplane, characterized in that it includes a display backplane main body, on which a plurality of solid crystal areas are arranged; the display backplane also includes a plurality of micro LED chips, and the plurality of micro LED chips are transferred to the solid crystal areas to complete bonding through the micro LED chip transfer method according to claim 8 or 9.

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