Temporary substrate and its manufacturing method, and micro-light emitting chip transfer method

Abstract

The present invention relates to a temporary substrate and a method for making the same, and a method for transferring a micro-light-emitting chip. A shielding layer is provided on the adhesive layer of the temporary substrate, and the shielding layer is provided with electrode accommodating holes for at least two electrodes of the micro-light-emitting chip to be inserted and bonded with the adhesive layer respectively, and an overflow port is provided between at least a portion of adjacent chip regions for the colloid of the adhesive layer to overflow, so that in the process of transferring the micro-light-emitting chip from the carrier substrate to the temporary substrate, the electrodes of the micro-light-emitting chip squeeze the adhesive layer on the temporary substrate, and the colloid of the adhesive layer can overflow from the overflow port when it is squeezed and deformed, and at the same time, a shielding layer is provided between the two electrodes of the micro-light-emitting chip to prevent the colloid from deforming and contacting the epitaxial layer of the micro-light-emitting chip, so that only the electrodes of the micro-light-emitting chip transferred to the temporary substrate are bonded with the adhesive layer, and the subsequent normal transfer of the micro-light-emitting chip can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and in particular to a temporary substrate and a manufacturing method thereof, and a micro-light-emitting chip transfer method. Background Art

[0002] At present, a key technology facing micro-LED (micro-Light Emitting Diode) is to transfer micro-LED chips to the display backplane through mass transfer. In the related technology, 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 micro-LED chip is transferred from the first temporary substrate to the display backplane using the second temporary substrate in a similar manner. In this process, the adhesive layer set on the first temporary substrate or the second temporary substrate will be squeezed by the electrodes of the micro-LED chip and will be deformed to a certain extent. It may contact and bond with the epitaxial layer of the micro-LED chip, but because it is not completely fluid, it will not level again after bonding with the epitaxial layer, and it will make it difficult to transfer the micro-LED chip after cooling and fixing.

[0003] Therefore, how to prevent the epitaxial layer of the LED chip from bonding with the colloid during the transfer process, which would lead to difficulties in subsequent transfer, 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 temporary substrate and a method for manufacturing the same, as well as a method for transferring a micro-light-emitting chip, aiming to solve the problem in the related technology that the epitaxial layer of the LED chip forms adhesion with the colloid during the transfer process, resulting in difficulty in subsequent transfer.

[0005] A temporary substrate, comprising:

[0006] substrate body;

[0007] An adhesive layer disposed on the substrate body;

[0008] A shielding layer is arranged on the adhesive layer, and the shielding layer has multiple chip areas; at least two electrode accommodating holes are arranged in the chip area and communicated with the adhesive layer, so that at least two electrodes of the micro light-emitting chip can be respectively inserted and bonded with the adhesive layer; an overflow port is arranged between at least a portion of adjacent chip areas for the colloid of the adhesive layer to overflow.

[0009] The above-mentioned temporary substrate has a shielding layer on its adhesive layer, and the shielding layer is provided with electrode accommodating holes for at least two electrodes of the corresponding micro-light-emitting chip to be respectively inserted and bonded with the adhesive layer, and an overflow port is provided between at least a portion of adjacent chip areas for the colloid of the adhesive layer to overflow. In this way, during the process of transferring the micro-light-emitting chip from the carrier substrate to the temporary substrate, the electrodes of the micro-light-emitting chip are squeezed against the adhesive layer on the temporary substrate, and the colloid of the adhesive layer can overflow from the overflow port when it is squeezed and deformed. At the same time, a shielding layer is provided between the two electrodes of the micro-light-emitting chip to prevent the deformation of the colloid and contact with the epitaxial layer of the micro-light-emitting chip, so that only the electrodes of the micro-light-emitting chip transferred to the temporary substrate are bonded with the adhesive layer, and other areas do not contact the adhesive layer, thereby ensuring the subsequent normal transfer of the micro-light-emitting chip.

[0010] Optionally, in an example of this embodiment, the temporary substrate also includes an expansion material layer arranged on the side wall of the electrode accommodating hole, and after the electrode is inserted into the electrode accommodating hole and bonded with the adhesive layer, the expansion material layer expands under a set expansion environment and fits tightly with the electrode.

[0011] By allowing the expandable material layer in the electrode accommodating hole to form a tight fit with the electrode after expansion, the colloid can be further prevented from overflowing along the gap between the electrode and the side wall of the electrode accommodating hole during the extrusion process. Therefore, it can be further improved to ensure that only the electrode of the micro light-emitting chip is bonded to the adhesive layer, and other areas are not in contact with the adhesive layer.

[0012] Optionally, in an example of this embodiment, the temporary substrate further includes an isolation wall disposed on the shielding layer to isolate the overflow port from the chip area.

[0013] The isolation wall can prevent the colloid overflowing from the overflow port from flowing to the chip area, thereby further preventing the side of the micro-light-emitting chip from contacting the overflowing colloid, and further ensuring the subsequent smooth transfer of the micro-light-emitting chip.

[0014] Based on the same inventive concept, the present application also provides a method for manufacturing a temporary substrate, comprising:

[0015] forming an adhesive layer on the substrate body;

[0016] forming a shielding layer on the adhesive layer, wherein the shielding layer has a plurality of chip areas;

[0017] At least two electrode accommodating holes communicating with the adhesive layer are formed in the chip area so that at least two electrodes of the micro light-emitting chip can be respectively inserted and bonded to the adhesive layer, and an overflow port for the colloid of the adhesive layer to overflow is formed between at least a portion of adjacent chip areas.

[0018] The temporary substrate made by the above temporary substrate making method, when used for chip transfer, can ensure that only the electrodes of the micro-light-emitting chip transferred to the temporary substrate are bonded to the adhesive layer, and other areas are not in contact with the adhesive layer, thereby ensuring the subsequent transfer of the micro-light-emitting chip.

[0019] Based on the same inventive concept, the present application also provides a micro-light-emitting chip transfer method, comprising:

[0020] Aligning and pressing one side of the carrier substrate carrying a plurality of micro-light-emitting chips to be transferred with the one side of the temporary substrate provided with the adhesive layer, after pressing, the electrodes of the micro-light-emitting chips are respectively inserted into the corresponding electrode receiving holes and embedded in the adhesive layer, and a part of the colloid squeezed from the adhesive layer overflows through the overflow port during the pressing process;

[0021] The carrying substrate is separated from the micro-light emitting chip, and the micro-light emitting chip is transferred to the temporary substrate.

[0022] The micro light-emitting chip transfer method uses the temporary substrate to transfer the micro light-emitting chip, which can ensure that only the electrodes of the micro light-emitting chip transferred to the temporary substrate are bonded to the adhesive layer, and other areas are not in contact with the adhesive layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of transferring a micro light-emitting chip from a growth substrate to a transfer substrate in the related art;

[0024] Figure 2-1 A schematic diagram of a temporary substrate provided in an embodiment of the present invention Figure 1 ;

[0025] Figure 2-2 for Figure 2-1 Schematic diagram of a temporary substrate for chip transfer;

[0026] Figure 3-1 Schematic diagram 2 of a temporary substrate provided in an embodiment of the present invention;

[0027] Figure 3-2 for Figure 3-1 Schematic diagram of a temporary substrate for chip transfer;

[0028] Figure 4-1 Schematic diagram 3 of a temporary substrate provided in an embodiment of the present invention;

[0029] Figure 4-2 for Figure 4-1 Schematic diagram of a temporary substrate for chip transfer;

[0030] Figure 5 Schematic diagram 4 of a temporary substrate provided by an embodiment of the present invention;

[0031] Figure 6 for Figure 5 Schematic diagram of a temporary substrate for chip transfer;

[0032] Figure 7-1 A schematic diagram of a temporary substrate provided in an embodiment of the present invention Figure 5 ;

[0033] Figure 7-2 for Figure 7-1 Schematic diagram of a temporary substrate for chip transfer;

[0034] Figure 8-1 A schematic diagram of a temporary substrate provided in an embodiment of the present invention Figure 6 ;

[0035] Figure 8-2 for Figure 8-1 Schematic diagram of a temporary substrate for chip transfer;

[0036] Fig. 9 A schematic diagram of a temporary substrate manufacturing method provided by another optional embodiment of the present invention;

[0037] Figure 10-1 A schematic diagram of a temporary substrate manufacturing method provided by another optional embodiment of the present invention Figure 1 ;

[0038] Figure 10-2 A schematic diagram of a temporary substrate manufacturing process provided by another optional embodiment of the present invention Figure 1 ;

[0039] Figure 11-1 A second schematic flow chart of a temporary substrate manufacturing method provided by another optional embodiment of the present invention;

[0040] Figure 11-2 Schematic diagram 2 of a temporary substrate manufacturing process provided by another optional embodiment of the present invention;

[0041] Figure 12-1 A schematic diagram of a micro-light-emitting chip transfer process provided by another optional embodiment of the present invention;

[0042] Figure 12-2 A schematic diagram of a temporary substrate used for chip transfer provided in yet another optional embodiment of the present invention;

[0043] Description of reference numerals:

[0044] 10-growth substrate, 11, 31-epitaxial layer, 12, 32-electrode, 13, 21-adhesive layer, 131, 211-colloid of the adhesive layer, 14-transfer substrate, 20-substrate body, 22-shielding layer, 23-chip area, 24-electrode accommodating hole, 25-overflow port, 26-expansion material layer, 27-isolation wall, 30-carrying substrate, 40-auxiliary substrate. DETAILED DESCRIPTION

[0045] 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.

[0046] 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.

[0047] In the related art, in the process of transferring the micro-LED chip from the growth substrate to the first temporary substrate, and then using the second temporary substrate in a similar manner to transfer the micro-LED chip from the first temporary substrate to the display backplane, the glue layer provided on the first temporary substrate or the second temporary substrate will be squeezed by the electrodes of the micro-LED chip and will be deformed to a certain extent. It may contact and bond with the epitaxial layer of the micro-LED chip, but because it is not completely fluid, it will not flow flat again after bonding with the epitaxial layer, and will make it difficult to transfer the micro-LED chip after cooling and fixing.

[0048] See for example Figure 1 As shown, during the process of pressing and embedding the electrode 12 of the micro-light-emitting chip on the growth substrate 10 into the adhesive layer 13 on the transfer substrate 14, the adhesive layer 13 is squeezed and deformed, and a part of the colloid 131 therein contacts and bonds with the epitaxial layer 11 of the micro-light-emitting chip, thereby making the subsequent transfer of the micro-light-emitting chip difficult or even causing transfer failure.

[0049] 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.

[0050] The temporary substrate illustrated in the present embodiment includes a substrate body, an adhesive layer arranged on the substrate body, and a shielding layer arranged on the adhesive layer, wherein the shielding layer has a plurality of chip regions; and each chip region is provided with at least two electrode accommodating holes communicated with the adhesive layer, so that at least two electrodes of the micro-light-emitting chip can be respectively inserted and bonded with the adhesive layer, so that the epitaxial layer between the two electrodes of the micro-light-emitting chip is isolated from the adhesive layer by the shielding layer, which can prevent the adhesive layer from being squeezed and deformed and contacting the epitaxial layer, and in the present embodiment, an overflow port for the colloid of the adhesive layer to overflow is provided between at least a portion of adjacent chip regions, so that the excess part of the colloid squeezed can overflow from the overflow port, so that only the electrode of the micro-light-emitting chip transferred to the temporary substrate is bonded with the adhesive layer, and other regions are not in contact with the adhesive layer, thereby ensuring the subsequent transfer of the micro-light-emitting chip.

[0051] It should be understood that in some application examples of the present embodiment, each chip region may correspond to a plurality of micro-light-emitting chips to be transferred on the carrier substrate one by one, or may be set to be non-one-to-one according to actual needs. For example, in some application scenarios, the number of micro-light-emitting chips to be transferred on the carrier substrate may be less than the number of chip regions.

[0052] It should be understood that the position and number of the overflow ports in this embodiment can be flexibly set, as long as the squeezed excess colloid can be discharged from the overflow ports and will not contact the micro-light-emitting chip. For example, in one application example, an overflow port for the colloid of the adhesive layer to overflow can be provided between all adjacent chip areas on the shielding layer, and the size and shape of the overflow port in this embodiment can be flexibly set according to the application scenario; for example, in some examples, the overflow port can be in the shape of a hole, and the shape of the hole is not limited, and can be a square hole, a circular hole, an elliptical hole, or a hole of any other shape; for example, in other examples, the overflow port can be a through groove.

[0053] In other application examples of this embodiment, an overflow port for the colloid of the adhesive layer to overflow may be provided only between a portion of adjacent chip regions. For example, N (N is greater than or equal to 2) adjacent chip regions may be a chip region group, and an overflow port may be provided between adjacent chip region groups. An overflow port may also be provided randomly in the region between some adjacent chips, or in the region between some adjacent chips using any other rule.

[0054] In this embodiment, the shape and size of the electrode accommodating hole provided on the shielding layer match the shape and size of the electrode.

[0055] It should be understood that the micro-light-emitting 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-light-emitting chip may be a micro-LED chip; in another example, the micro-light-emitting chip may be a mini-LED chip.

[0056] It should be understood that the micro-light-emitting 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-light-emitting chip may be a flip-chip LED chip; in another example, the micro-light-emitting chip may be a face-mounted LED chip.

[0057] The micro-light-emitting chip in this embodiment includes but is not limited to an epitaxial layer and an electrode. This embodiment does not limit the specific structure of the epitaxial layer of the micro-light-emitting chip. In one example, the epitaxial layer of the micro-light-emitting 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.

[0058] It should be understood that the material of the substrate body in this embodiment is not limited, and it can be any one of glass, sapphire, quartz and silicon, but is not limited to it.

[0059] It should be understood that the carrier substrate in this embodiment can be a growth substrate, and the substrate body in this case can be the body of the first temporary substrate; and the material of the growth substrate can be various semiconductor materials on which the micro-light-emitting chip can be grown, for example, the material of the growth substrate can be but not limited to sapphire, silicon carbide, silicon, gallium arsenide, or other semiconductor materials, which are not limited here. It should also be understood that the carrier substrate is not limited to the growth substrate, and can also be the first temporary substrate for carrying the micro-light-emitting chip, and the temporary substrate in this embodiment can be the second temporary substrate.

[0060] The shielding layer in this embodiment may be made of various materials with good hardness, such as but not limited to a metal layer or an inorganic material layer.

[0061] For ease of understanding, the following description is given with reference to the temporary substrate setting example in the accompanying drawings.

[0062] For an example of a setup, see Figure 2-1As shown, an adhesive layer 21 is provided on the substrate body 20, and a shielding layer 22 is provided on the adhesive layer 21, wherein the shielding layer 22 has a plurality of chip regions 23, and one chip region 23 corresponds to one micro-light-emitting chip on the carrier substrate. Two electrode accommodating holes 24 are provided in each chip region 23 (it should be understood that the number of electrode accommodating holes can be provided in accordance with the number of electrodes of the micro-light-emitting chip), and an overflow port 25 is provided between adjacent chip regions 23.

[0063] In this example, when transferring the micro-light emitting chip from the carrier substrate to the temporary substrate, see Figure 2-2 As shown, the side of the carrier substrate 30 provided with the micro-light-emitting chip is laminated with the side of the substrate body 20 provided with the adhesive layer 21, and a certain pressure is applied to make the electrode 32 of the micro-light-emitting chip embedded in the adhesive layer 21. During the lamination process, a part of the excess colloid 211 is squeezed out from the overflow port 25, thereby preventing the colloid from overflowing from between the two electrodes of the micro-light-emitting chip and forming a bond with the epitaxial layer 31 of the micro-light-emitting chip, which is more conducive to the subsequent transfer of the micro-light-emitting chip from the substrate body 20.

[0064] For another example of a setup, see Figure 3-1 As shown, an adhesive layer 21 is provided on the substrate body 20, and a shielding layer 22 is provided on the adhesive layer 21, wherein the shielding layer 22 has a plurality of chip regions 23, and one chip region 23 corresponds to one micro light-emitting chip on the carrier substrate. Two electrode accommodating holes 24 are provided in each chip region 23, and two adjacent chip regions 23 form a chip region group, and an overflow port 25 is provided between adjacent chip region groups.

[0065] In this example, when transferring the micro-light emitting chip from the carrier substrate to the temporary substrate, see Figure 3-2 As shown, the side of the carrier substrate 30 provided with the micro-light-emitting chip is laminated with the side of the substrate body 20 provided with the adhesive layer 21, and a certain pressure is applied to make the electrode 32 of the micro-light-emitting chip embedded in the adhesive layer 21. During the lamination process, a part of the excess colloid 211 is squeezed out from the overflow port 25, which can also prevent the colloid from overflowing from between the two electrodes of the micro-light-emitting chip and forming a bond with the epitaxial layer 31 of the micro-light-emitting chip.

[0066] Optionally, in some examples of the present embodiment, in order to prevent the colloid from overflowing along the gap between the electrode and the side wall of the electrode accommodating hole during the extrusion process, the temporary substrate also includes an expansion material layer arranged on the side wall of the electrode accommodating hole. After the electrode is inserted into the electrode accommodating hole and bonded with the adhesive layer, the expansion material layer expands under a set expansion environment to form a tight fit with the electrode, which can further enhance and ensure that only the electrode of the micro light-emitting chip is bonded with the adhesive layer, and other areas are not in contact with the adhesive layer.

[0067] The material of the expansion material layer in this embodiment can be various materials that can expand under a set expansion environment and do not damage the electrode, for example, a heat expansion material layer or a water absorption expansion material layer.

[0068] When it is a heat-expandable material layer, it can be heated to expand it and form a close fit with the electrode. The heating environment can be an environment for heating and debonding the adhesive layer.

[0069] When the water-swellable material layer is used, it can be placed in a water-absorbing environment so that the swellable material layer absorbs water and swells, and the binding force between the swellable material layer and the electrode becomes smaller during the expansion process. In some examples, the water-swellable material can be, but is not limited to, an organic porous material or lithium fluoride.

[0070] It should be understood that the water absorption environment in this embodiment can be flexibly set as long as it can make the expansion material layer absorb water and expand, thereby making the expansion material layer gradually more closely contacted with the electrode during the expansion process.

[0071] For example, in some examples, the water absorption environment can be set to an air humidity of 50% to 100% and an ambient temperature of normal temperature.

[0072] Optionally, in some examples of this embodiment, in order to improve the efficiency of the expansion material layer absorbing water and expanding, the ambient temperature and air pressure may be appropriately increased, thereby improving the transfer efficiency. For example, in one example, the water absorption environment may include but is not limited to:

[0073] The air humidity is 50% to 100%; for example, the air humidity may be, but is not limited to, 50%, 60%, 70%, 80%, 90%, 100%;

[0074] The ambient temperature is 60°C to 85°C; for example, the ambient temperature can be set to, but not limited to, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C;

[0075] The air pressure is 1.5 standard atmospheres to 2 standard atmospheres, for example, it can be set to but not limited to 1.5 standard atmospheres, 1.6 standard atmospheres, 1.7 standard atmospheres, 1.8 standard atmospheres, 2 standard atmospheres, etc.

[0076] For ease of understanding, the following description is given with reference to the temporary substrate setting example in the accompanying drawings.

[0077] For an example of a setup, see Figure 4-1As shown, an adhesive layer 21 is provided on the substrate body 20, and a shielding layer 22 is provided on the adhesive layer 21, wherein the shielding layer 22 has a plurality of chip areas 23, and one chip area 23 corresponds to one micro-light-emitting chip on the carrier substrate. Two electrode accommodating holes 24 are provided in each chip area 23, and an overflow port 25 is provided between at least a portion of two adjacent chip areas 23. An expansion material layer 26 is provided on the side wall of the electrode accommodating hole 24. After the expansion material layer 26 is provided on the side wall of the electrode accommodating hole 24, the aperture enclosed by the expansion material layer 26 matches the size of the electrode of the micro-light-emitting chip, for example, it can be equal to or slightly larger than the size of the electrode.

[0078] In this example, when transferring the micro-light emitting chip from the carrier substrate to the temporary substrate, see Figure 4-2 As shown, the side of the carrier substrate 30 provided with the micro-light-emitting chip is laminated with the side of the substrate body 20 provided with the adhesive layer 21, and then they are placed in an expansion environment and a certain pressure is applied so that the electrode 32 of the micro-light-emitting chip is embedded in the adhesive layer 21, and the expansion material layer 26 forms a close contact with the electrode 32 after expansion, so as to prevent the colloid from overflowing from between the two. During the lamination process, a part of the excess colloid 211 is squeezed out from the overflow port 25, so as to prevent the colloid from overflowing from between the two electrodes of the micro-light-emitting chip and forming a bond with the epitaxial layer 31 of the micro-light-emitting chip.

[0079] Optionally, in some examples of the present embodiment, in order to prevent the colloid overflowing from the overflow port from flowing to the chip area, the side of the micro-light-emitting chip is further prevented from contacting with the overflowed colloid, so as to ensure the subsequent smooth transfer of the micro-light-emitting chip. The temporary substrate also includes an isolation wall arranged on the shielding layer to isolate the overflow port from the chip area, and the sum of the heights of the isolation wall and the shielding layer is less than or equal to the total height of the micro-light-emitting chip minus the height of the electrode of the micro-light-emitting chip embedded in the adhesive layer. By setting up the isolation wall, the colloid overflowing from the overflow port can be prevented from flowing to the chip area, thereby further preventing the side of the micro-light-emitting chip from contacting with the overflowed colloid, and ensuring the subsequent smooth transfer of the micro-light-emitting chip.

[0080] In some examples of the present embodiment, the sum of the heights of the isolation wall and the shielding layer can be equal to the total height of the micro-light-emitting chip minus the height of the portion of the micro-light-emitting chip where the electrode is embedded in the adhesive layer. Thus, after the height of the micro-light-emitting chip where the electrode is embedded in the adhesive layer reaches a certain level, it can be blocked by the isolation wall to prevent it from being further embedded in the adhesive layer. At this time, the isolation wall can also play a limiting role.

[0081] In one example of this embodiment, the isolation wall can be integrally formed with the shielding layer, for example, the isolation wall can also be made of metal material or inorganic material. In another example of this embodiment, the isolation wall and the shielding layer may not be integrally formed structures, and its material can be different from that of the shielding layer, for example, it can be an organic material; of course, it can also be the same as the material of the shielding layer, for example, it can also be made of metal material or inorganic material.

[0082] For ease of understanding, the following description is given with reference to the temporary substrate setting example in the accompanying drawings.

[0083] For an example of a setup, see Figure 5 As shown, an adhesive layer 21 is provided on the substrate body 20, and a shielding layer 22 is provided on the adhesive layer 21, wherein the shielding layer 22 has a plurality of chip regions 23, and one chip region 23 corresponds to one micro-light-emitting chip on the carrier substrate. Two electrode accommodating holes 24 are provided in each chip region 23, and an overflow port 25 is provided between each two adjacent chip regions 23. An expansion material layer 26 is provided on the side wall of the electrode accommodating hole 24, and an isolation wall 27 is provided on the shielding layer 22 to isolate each overflow port from the chip region.

[0084] In this example, when transferring the micro-light emitting chip from the carrier substrate to the temporary substrate, see Figure 6 As shown, the side of the carrier substrate 30 provided with the micro-light-emitting chip is laminated with the side of the substrate body 20 provided with the adhesive layer 21, and then the substrate is placed in an expansion environment and a certain pressure is applied so that the electrode 32 of the micro-light-emitting chip is embedded in the adhesive layer 21, and the expansion material layer 26 forms a close contact with the electrode 32 after expansion, so as to prevent the colloid from overflowing from between the two. During the lamination process, a part of the excess colloid 211 is squeezed out from the overflow port 25, and the overflowed colloid 211 is blocked by the isolation wall 27 to prevent it from flowing to the chip area, so as to prevent the colloid from overflowing from between the two electrodes of the micro-light-emitting chip and forming a bond with the epitaxial layer 31 of the micro-light-emitting chip; and the isolation wall 27 can also prevent the electrode of the micro-light-emitting chip from being excessively embedded in the adhesive layer.

[0085] For another example of a setup, see Figure 7-1 As shown, an adhesive layer 21 is provided on the substrate body 20, and a shielding layer 22 is provided on the adhesive layer 21, wherein the shielding layer 22 has a plurality of chip regions 23. Two electrode accommodating holes 24 are provided in each chip region 23, and two adjacent chip regions 23 form a chip region group, and an overflow port 25 is provided between adjacent chip region groups. An expansion material layer 26 is provided on the side wall of the electrode accommodating hole 24, and an isolation wall 27 is provided on the shielding layer 22 to isolate each overflow port from the chip region. In this example, when the micro-light-emitting chip is transferred from the carrier substrate to the temporary substrate, see Figure 7-2As shown, the side of the carrier substrate 30 provided with the micro-light-emitting chip is laminated with the side of the substrate body 20 provided with the adhesive layer 21, and then they are placed in an expansion environment (e.g., a heating environment) and a certain pressure is applied so that the electrode 32 of the micro-light-emitting chip is embedded in the adhesive layer 21, and the expansion material layer 26 forms a close contact with the electrode 32 after expansion, so as to prevent the colloid from overflowing from between the two. During the lamination process, a part of the excess colloid 211 is squeezed out from the overflow port 25, and the overflowed colloid 211 is blocked by the isolation wall 27 to prevent it from flowing to the chip area, so as to prevent the colloid from overflowing from between the two electrodes of the micro-light-emitting chip and forming a bond with the epitaxial layer 31 of the micro-light-emitting chip; and the isolation wall 27 can also prevent the electrode of the micro-light-emitting chip from being excessively embedded in the adhesive layer.

[0086] It should be understood that in this embodiment, the isolation wall 27 can be set at the edge of each overflow port, or at any other position on the shielding layer 22, as long as the above purpose can be achieved. For example, see Figure 8-1 to Figure 8-2 As shown, it is Figure 7-1 and Figure 7-2 Compared with the structure shown in the figure, the main difference is that the isolation wall 27 is arranged closer to the electrode accommodating hole 24.

[0087] Another optional embodiment of the present invention:

[0088] This embodiment provides a method for manufacturing a temporary substrate as shown in the above embodiment, but it should be understood that the method for manufacturing a temporary substrate in this embodiment is only an example of manufacturing, and the manufacturing of a temporary substrate is not limited to the method shown in this embodiment. Fig. 9 As shown, the method for making the temporary substrate shown in this embodiment includes but is not limited to:

[0089] S901: Provide base body.

[0090] S902: forming an adhesive layer on the substrate body.

[0091] It should be understood that the material and formation process of the adhesive layer in this embodiment are not limited. For example, the adhesive layer can be formed on the front side of the substrate body by, but not limited to, coating, printing, molding, etc.

[0092] S903: forming a shielding layer on the adhesive layer, wherein the shielding layer has a plurality of chip regions.

[0093] In this embodiment, there is no limitation on the specific material and formation process of the shielding layer. For example, in some instances, it may be made of metal or inorganic material, and the shielding layer may be formed by methods including but not limited to deposition and evaporation.

[0094] S904: forming at least two electrode receiving holes in the chip area and communicating with the adhesive layer, so that at least two electrodes of the corresponding micro light-emitting chip can be respectively inserted and bonded with the adhesive layer, and forming an overflow port between at least a portion of adjacent chip areas for the colloid of the adhesive layer to overflow.

[0095] In this embodiment, the electrode receiving hole and the overflow port can be formed in the same process step or in different process steps, and the formation method adopted can include but is not limited to etching, cutting, etc. on the shielding layer.

[0096] Optionally, in this example, in order to prevent the colloid from overflowing along the gap between the electrode and the side wall of the electrode receiving hole during the extrusion process, after at least two electrode receiving holes isolated by the shielding layer and communicating with the adhesive layer are formed in the chip area, the following may also be included but are not limited to:

[0097] An expansion material layer is formed on the side wall of the electrode receiving hole. After the electrode is inserted into the electrode receiving hole and bonded to the adhesive layer, the expansion material layer expands under a set expansion environment to form a tight fit with the electrode.

[0098] Optionally, in this example, in order to prevent the colloid overflowing from the overflow port from flowing to the chip area, the side of the micro-light-emitting chip is further prevented from contacting the overflowed colloid, so as to ensure the subsequent smooth transfer of the micro-light-emitting chip. The temporary substrate also includes a separation wall arranged on the shielding layer to isolate the overflow port from the chip area, and the height of the separation wall is less than or equal to the total height of the micro-light-emitting chip minus the height of the portion of the micro-light-emitting chip where the electrode is embedded in the adhesive layer. In one example, after an overflow port for the colloid of the adhesive layer to overflow is formed between at least a portion of adjacent chip areas, it may also include: forming a separation wall on the shielding layer to isolate the overflow port from the chip area, and the height of the separation wall is less than or equal to the total height of the micro-light-emitting chip minus the height of the portion of the micro-light-emitting chip where the electrode is embedded in the adhesive layer.

[0099] In some other examples of this embodiment, the isolation wall may be formed simultaneously during the process of forming the overflow port.

[0100] For ease of understanding, this embodiment is described below with reference to two temporary substrate manufacturing methods shown in FIG. 10 and FIG. 11 as examples.

[0101] A method for making a temporary substrate can be found in Figure 10-1 to Figure 10-2 As shown, it includes but is not limited to:

[0102] S1001 : forming a hard shielding layer 22 on the auxiliary substrate 40 by deposition (eg physical vapor deposition) or evaporation.

[0103] The shielding layer 22 may be, but is not limited to, a hard metal layer or a hard inorganic layer.

[0104] S1002 : forming an adhesive layer 21 on the substrate body 20 .

[0105] It should be understood that step S1001 may be executed simultaneously with step S1002, or step S1001 may be executed first and then S1002, or step S1002 may be executed first and then S1001.

[0106] S1003 : Decompress and bond the side of the auxiliary substrate 40 provided with the shielding layer 22 to the adhesive layer 21 on the substrate body 20 at high temperature.

[0107] In this step, the shielding layer 22 is bonded to the adhesive layer. At the same time, since the shielding layer 22 has a good planar shape, the adhesive layer 21 can be flattened under a certain pressure.

[0108] S1004: removing the auxiliary substrate 40.

[0109] The auxiliary substrate 20 may be removed to expose the shielding layer 22 by means of, but not limited to, physical grinding, plasma etching, chemical corrosion, etc. Optionally, a certain margin may be reserved for the thickness of the shielding layer 22 to prevent the removal of the auxiliary substrate 20 from causing insufficient thickness of the shielding layer 22.

[0110] S1005 : forming an electrode accommodating hole 24 and an overflow port 25 on the shielding layer 22 .

[0111] For example, the shielding layer 22 can be formed into a pattern with an electrode accommodating hole 24 and an overflow port 25 through, but not limited to, photolithography and etching. The shielding layer 22 reserves an electrode accommodating hole 24 corresponding to the electrode of the micro-light-emitting chip. The pattern of the electrode accommodating hole 24 is the same as the electrode of the micro-light-emitting chip, and the size is slightly larger than the electrode of the micro-light-emitting chip. At the same time, an opening is reserved between the chip areas corresponding to adjacent micro-light-emitting chips as the overflow port 25, and the shape is not limited.

[0112] S1006 : forming an expansion material layer 26 in the electrode accommodating hole 24 and the overflow port 25 on the shielding layer 22 .

[0113] S1007: The middle area of ​​the expansion material layer 26 in the electrode accommodating hole 24 is removed, and the expansion material layer 26 on the side wall of the electrode accommodating hole 24 is retained; and the expansion material layer 26 in the overflow port is completely removed.

[0114] For example, an expansion material layer 26 having a large thermal expansion coefficient or water absorption expansion coefficient can be formed in the electrode accommodating hole 24 by coating, photolithography, etc. After forming a buffer, the diameter of the opening enclosed by the expansion material layer 26 is slightly larger than the size of the electrode of the micro light-emitting chip.

[0115] S1008 : forming a material layer of a whole isolation wall 27 on the shielding layer 22 .

[0116] The material layer of the isolation wall 27 may be an organic material layer, and may be a photoresist layer or a non-photoresist layer.

[0117] S1009 : Partially remove the material layer of the isolation wall 27 , and the remaining material layer of the isolation wall 27 forms the isolation wall 27 .

[0118] The height of the formed isolation wall 27 plus the height of the shielding layer = the total height of the micro light-emitting chip (eg, the sum of the height of the epitaxial layer and the height of the electrode) minus the depth of the electrode to be pressed into the glue.

[0119] In this example, if the organic material used in the material layer of the isolation wall 27 is already a photosensitive photoresist material, it can be directly photolithographically patterned without etching.

[0120] Another method for making a temporary substrate can be found in Figure 11-1 to Figure 11-2 As shown, it includes but is not limited to:

[0121] S1101 : forming a hard shielding layer 22 on the auxiliary substrate 40 by deposition (eg, physical vapor deposition) or evaporation.

[0122] The shielding layer 22 may be, but is not limited to, a hard metal layer or a hard inorganic layer, and its height (also referred to as thickness) is less than or equal to the total height of the micro light-emitting chip (for example, the sum of the height of the epitaxial layer and the height of the electrode minus the depth of the electrode to be pressed into the glue).

[0123] S1102 : forming an adhesive layer 21 on the substrate body 20 .

[0124] It should be understood that step S1101 may be executed simultaneously with step S1102, or step S1101 may be executed first and then S1102, or step S1102 may be executed first and then S1101.

[0125] S1103 : Decompress and bond the side of the auxiliary substrate 40 provided with the shielding layer 22 to the adhesive layer 21 on the substrate body 20 at high temperature.

[0126] In this step, the shielding layer 22 is bonded to the adhesive layer. At the same time, since the shielding layer 22 has a good planar shape, the adhesive layer 21 can be flattened under a certain pressure.

[0127] S1104: removing the auxiliary substrate 40.

[0128] The auxiliary substrate 20 may be removed to expose the shielding layer 22 by means of, but not limited to, physical grinding, plasma etching, chemical corrosion, etc. Optionally, a certain margin may be reserved for the thickness of the shielding layer 22 to prevent the removal of the auxiliary substrate 20 from causing insufficient thickness of the shielding layer 22.

[0129] S1105 : forming an electrode accommodating hole 24 , an overflow port 25 and a shielding wall 27 on the shielding layer 22 .

[0130] For example, the shielding layer 22 can be formed into a pattern with an electrode accommodating hole 24, an overflow port 25 and a shielding wall 27 by, but not limited to, photolithography and etching. The shielding layer 22 leaves an electrode accommodating hole 24 corresponding to the electrode of the micro-light-emitting chip. The pattern of the electrode accommodating hole 24 is the same as the electrode of the micro-light-emitting chip, and the size is slightly larger than the electrode of the micro-light-emitting chip. At the same time, an opening is left between the chip regions corresponding to adjacent micro-light-emitting chips as an overflow port 25, and the shape is not limited. The height of the formed isolation wall 27 plus the height of the shielding layer = the total height of the micro-light-emitting chip (for example, the sum of the height of the epitaxial layer and the height of the electrode) minus the depth of the electrode to be pressed into the glue material.

[0131] S1106 : forming an expansion material layer 26 in the electrode accommodating hole 24 and the overflow port 25 on the shielding layer 22 .

[0132] S1107: The middle area of ​​the expansion material layer 26 in the electrode accommodating hole 24 is removed, and the expansion material layer 26 on the side wall of the electrode accommodating hole 24 is retained; and the expansion material layer 26 in the overflow port is completely removed.

[0133] For example, an expansion material layer 26 having a large thermal expansion coefficient or water absorption expansion coefficient can be formed in the electrode accommodating hole 24 by coating, photolithography, etc. After forming a buffer, the diameter of the opening enclosed by the expansion material layer 26 is slightly larger than the size of the electrode of the micro light-emitting chip.

[0134] Another optional embodiment of the present invention:

[0135] This embodiment also provides a micro-light-emitting chip transfer method, including:

[0136] Aligning and pressing one side of the carrier substrate carrying the plurality of micro-light-emitting chips to be transferred with the one side of the temporary substrate provided with the adhesive layer, after pressing, the electrodes of the micro-light-emitting chips are respectively inserted into the corresponding electrode receiving holes and embedded in the adhesive layer, and a part of the colloid squeezed from the adhesive layer overflows through the overflow port during the pressing process;

[0137] The carrying substrate is separated from the micro-light-emitting chip, and the micro-light-emitting chip is transferred to the temporary substrate.

[0138] For ease of understanding, this embodiment is described below in conjunction with a transfer example. Figure 12-1 to Figure 12-2 As shown, it includes but is not limited to:

[0139] S1201 : generating a micro light-emitting chip on the carrier substrate 30 .

[0140] In this example, the carrier substrate 30 is a growth substrate, and the temporary substrate 20 is a first temporary substrate. Of course, in some application scenarios, the carrier substrate 30 may also be a first temporary substrate, and the temporary substrate 20 may be a second temporary substrate.

[0141] S1202 : Laminating the side of the carrier substrate 30 on which the micro-light-emitting chip is grown with the side of an exemplary temporary substrate 20 on which the shielding layer 22 is provided.

[0142] The carrier substrate 30 is aligned and fitted with the temporary substrate 20, and then heated and pressurized. At this time, since the expansion material layer 26 has a large thermal expansion coefficient, after thermal expansion, it will be tightly fitted around the electrode 32 of the micro-light-emitting chip to form a seal; then, the electrode 32 of the micro-light-emitting chip is pressed into the adhesive material of the adhesive layer 21, and the extruded adhesive material will not protrude from the two sides of the micro-light-emitting chip or from between the two electrodes of the micro-light-emitting chip due to the blocking layer 22, but will be squeezed out from the overflow port, thereby preventing the adhesive material from affecting the micro-light-emitting chip; at the same time, the existence of the isolation wall 27 can prevent the electrode 32 of the micro-light-emitting chip from being pressed into the adhesive layer abnormally even if the pressure is too large, and at the same time, the isolation wall 27 is wrapped around the overflow port to prevent the extruded adhesive material from flowing around the micro-light-emitting chip, and the space volume enclosed by the isolation wall 27 only needs to ensure that the height of the extruded adhesive material cannot touch the carrier substrate 30.

[0143] S1203: Separate the carrier substrate 30 from the micro light-emitting chip.

[0144] In this step, the carrier substrate 30 is peeled off, and after the temperature drops, the expansion material layer 26 will return to its original size (when the expansion material layer 26 is a water-absorbing expansion material, it can be dehydrated and restored to its original size by heating or other methods), which will not affect the subsequent transfer of the micro light-emitting chip; then, the micro light-emitting chip is transferred from the temporary substrate to other substrates or transferred and welded to a specific position on the backplane through weakening structure, transfer head transfer, etc.

[0145] It should be noted that the transfer method of the micro light-emitting chip provided in the present application is not only applicable to the micro light-emitting chip, but also to other micro chips with similar transfer processes, and also to light-emitting chips of ordinary sizes that need to be transferred.

[0146] 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 temporary substrate, characterized in that: include: substrate body; An adhesive layer disposed on the substrate body; A shielding layer disposed on the adhesive layer, wherein the shielding layer has a plurality of chip areas; At least two electrode accommodating holes communicating with the adhesive layer are provided in the chip region, so that at least two electrodes of the micro light-emitting chip can be respectively inserted and bonded to the adhesive layer; an overflow port for the colloid of the adhesive layer to overflow is provided between at least a portion of adjacent chip regions.

2. The temporary substrate according to claim 1, characterized in that An overflow port is provided between all adjacent chip regions for the colloid of the adhesive layer to overflow.

3. The temporary substrate according to claim 1, characterized in that The shielding layer is a metal layer or an inorganic material layer.

4. The temporary substrate according to any one of claims 1 to 3, characterized in that: The temporary substrate also includes an expansion material layer disposed on the side wall of the electrode accommodating hole. After the electrode is inserted into the electrode accommodating hole and bonded to the adhesive layer, the expansion material layer expands under a set expansion environment and fits tightly with the electrode.

5. The temporary substrate according to claim 4, characterized in that The expansion material layer is a heat expansion material layer or a water absorption expansion material layer.

6. The temporary substrate according to any one of claims 1 to 3, characterized in that: The temporary substrate also includes an isolation wall which is arranged on the shielding layer and isolates the overflow port from the chip area.

7. A method for making a temporary substrate, characterized in that: include: forming an adhesive layer on the substrate body; forming a shielding layer on the adhesive layer, wherein the shielding layer has a plurality of chip areas; At least two electrode accommodating holes communicating with the adhesive layer are formed in the chip area so that at least two electrodes of the micro light-emitting chip can be respectively inserted and bonded to the adhesive layer, and an overflow port for the colloid of the adhesive layer to overflow is formed between at least a portion of adjacent chip areas.

8. The method for manufacturing a temporary substrate according to claim 7, characterized in that: After forming at least two electrode accommodating holes in the chip region and communicating with the adhesive layer, the method further comprises: An expansion material layer is formed on the side wall of the electrode accommodating hole. After the electrode is inserted into the electrode accommodating hole and bonded to the adhesive layer, the expansion material layer expands under a set expansion environment and closely fits the electrode.

9. The method for manufacturing a temporary substrate according to claim 7 or 8, characterized in that: After forming an overflow port for the colloid of the adhesive layer to overflow between at least a portion of the adjacent chip regions, the method further includes: An isolation wall is formed on the shielding layer to isolate the overflow port from the chip area.

10. A method for transferring a micro-luminescent chip, characterized in that: include: Aligning and pressing a side of the carrier substrate carrying a plurality of micro-light-emitting chips to be transferred with a side of the temporary substrate according to any one of claims 1 to 6 provided with the adhesive layer, wherein after pressing, each electrode of the micro-light-emitting chip is respectively inserted into the corresponding electrode receiving hole and embedded in the adhesive layer, and a part of the colloid squeezed from the adhesive layer overflows through the overflow port during the pressing process; The carrying substrate is separated from the micro-light emitting chip, and the micro-light emitting chip is transferred to the temporary substrate.

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