CN114388420A - Temporary substrate, manufacturing method thereof and micro light-emitting chip transfer method - Google Patents

Abstract

The present invention relates to a temporary substrate and a manufacturing method thereof, and a transfer method of a micro light-emitting chip. A shielding layer is arranged on the adhesive layer of the temporary substrate, and the shielding layer is provided with electrode accommodating holes for inserting at least two electrodes of the micro light-emitting chip respectively and forming bonding with the adhesive layer, and at least a part of the adjacent electrodes is provided with an electrode receiving hole. There is an overflow port for the colloid of the adhesive layer to overflow between the chip areas, so that 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 press the adhesive layer on the temporary substrate. During the process, 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 from contacting the epitaxial layer of the micro light-emitting chip, so that the transfer to The micro-light-emitting chip on the temporary substrate only has the electrodes and the adhesive layer to form a bond, which can ensure the subsequent normal transfer of the micro-light-emitting chip.

Description

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

technical field

The invention relates to the field of semiconductor devices, in particular to a temporary substrate and a method for making the same, and a method for transferring a micro light-emitting chip.

Background technique

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 art, generally, a releasable adhesive layer is provided on the first temporary substrate, and the micro-LED chip is transferred from the growth substrate to the first temporary substrate through adhesion through the releasable adhesive layer. A second temporary substrate is used to transfer the micro-LED chips from the first temporary substrate to the display backplane. In this process, the adhesive layer set on the first temporary substrate or the second temporary substrate will be deformed to a certain extent by the extrusion of the electrodes of the micro-LED chip, and may contact with the epitaxial layer of the micro-LED chip to form a bond, but Because it is not completely fluid, it will not be leveled after bonding with the epitaxial layer, which will cause difficulties in transferring the micro-LED chip after cooling and fixing.

Therefore, how to avoid the bonding between the epitaxial layer and the colloid of the LED chip during the transfer process, resulting in difficulty in subsequent transfer, is an urgent problem to be solved.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies in the related art, the purpose of the present application is to provide a temporary substrate and a method for making the same, and a method for transferring a micro light-emitting chip, aiming to solve the problem that the epitaxial layer of the LED chip and the colloid form adhesion during the transfer process in the related art. , leading to the difficulty of subsequent transfer.

A temporary substrate comprising:

substrate body;

an adhesive layer disposed on the substrate body;

A shielding layer disposed on the adhesive layer, the shielding layer has a plurality of chip areas; the chip area is provided with at least two electrode accommodating holes communicated with the adhesive layer for micro At least two electrodes of the light-emitting chip are respectively inserted and bonded with the adhesive layer; at least a part of adjacent chip regions are provided with overflow ports for the colloid of the adhesive layer to overflow.

The above temporary substrate is provided with a shielding layer on the adhesive layer, and the shielding layer is provided with electrode accommodating holes for inserting at least two electrodes of the corresponding micro light-emitting chip respectively and forming adhesion with the adhesive layer, and at least A part of adjacent chip areas is provided with an overflow port for the colloid of the adhesive layer to overflow, so that 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 adhere to the temporary substrate. During the extrusion process of the adhesive layer, the colloid adhering to 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 from contacting the epitaxial layer of the micro light-emitting chip. As a result, 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 normal transfer of the micro light-emitting chip.

Optionally, in an example of this embodiment, the temporary substrate further includes an expansion material layer disposed on a side wall of the electrode accommodating hole, and the expansion material layer is inserted into the electrode accommodating hole when the electrode is inserted into the electrode accommodating hole. After the hole is formed and bonded with the adhesive layer, it expands under a set expansion environment, and closely adheres to the electrode.

The expansion material layer in the electrode accommodating hole forms a close contact with the electrode after expansion, which can further prevent the colloid from overflowing along the gap between the electrode and the side wall of the electrode accommodating hole during the extrusion process, so it can further improve the guarantee of micro-luminescence Only the electrodes of the chip form a bond with the adhesive layer, and other areas are not in contact with the adhesive layer.

Optionally, in an example of this embodiment, the temporary substrate further includes an isolation wall disposed on the shielding layer and isolating the overflow port from the chip area.

The arrangement of 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.

Based on the same inventive concept, the present application also provides a method for manufacturing a temporary substrate, including:

forming an adhesive layer on the substrate body;

forming a shielding layer on the adhesive layer, the shielding layer has a plurality of chip areas;

At least two electrode receiving holes communicated 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 with the adhesive layer, and at least two electrodes of the micro light-emitting chip can be inserted into the adhesive layer. An overflow port for the colloid of the adhesive layer to overflow is formed between a part of the adjacent chip regions.

The temporary substrate prepared by the above-mentioned manufacturing method of the temporary substrate can ensure that only the electrodes and the adhesive layer of the micro light-emitting chip transferred to the temporary substrate are bonded when it is applied to the chip transfer, and other areas are not connected to the adhesive layer. contact, thereby ensuring the subsequent transfer of the micro light-emitting chip.

Based on the same inventive concept, the present application also provides a method for transferring a micro light-emitting chip, including:

Align and press the side of the carrier substrate that carries the micro-light-emitting chips to be transferred with the side of the temporary substrate provided with the adhesive layer, after pressing, the electrodes of the micro-light-emitting chips are pressed together. Insert the corresponding electrode accommodating holes respectively and embed them in the adhesive layer, and a part of the colloid squeezed by the adhesive layer during the pressing process overflows through the overflow port;

The carrier substrate is separated from the micro light-emitting chip, and the transfer of the micro light-emitting chip to the temporary substrate is completed.

The above-mentioned micro-light-emitting chip transfer method uses the above-mentioned temporary substrate to transfer the micro-light-emitting chip, which can ensure that the micro-light-emitting chip transferred to the temporary substrate only has electrodes bonded to the adhesive layer, and other areas are not in contact with the adhesive layer. .

Description of drawings

FIG. 1 is a schematic diagram of the transfer of a micro light-emitting chip from a growth substrate to a transfer substrate in the related art;

FIG. 2-1 is a schematic diagram 1 of a temporary substrate provided by an embodiment of the present invention;

Fig. 2-2 is a schematic diagram of the temporary substrate in Fig. 2-1 used for chip transfer;

FIG. 3-1 is a second schematic diagram of a temporary substrate provided by an embodiment of the present invention;

Fig. 3-2 is a schematic diagram of the temporary substrate in Fig. 3-1 used for chip transfer;

FIG. 4-1 is a schematic diagram 3 of a temporary substrate provided by an embodiment of the present invention;

Fig. 4-2 is a schematic diagram of the temporary substrate in Fig. 4-1 used for chip transfer;

FIG. 5 is a schematic diagram 4 of a temporary substrate provided by an embodiment of the present invention;

FIG. 6 is a schematic diagram of the temporary substrate in FIG. 5 used for chip transfer;

FIG. 7-1 is a schematic diagram 5 of a temporary substrate provided by an embodiment of the present invention;

Fig. 7-2 is a schematic diagram of the temporary substrate in Fig. 7-1 used for chip transfer;

FIG. 8-1 is a schematic diagram VI of a temporary substrate provided by an embodiment of the present invention;

Fig. 8-2 is a schematic diagram of the temporary substrate in Fig. 8-1 used for chip transfer;

FIG. 9 is a schematic diagram of a method for fabricating a temporary substrate provided by another optional embodiment of the present invention;

FIG. 10-1 is a schematic flow chart 1 of a method for fabricating a temporary substrate provided by another optional embodiment of the present invention;

10-2 is a schematic diagram 1 of a manufacturing process of a temporary substrate provided by another optional embodiment of the present invention;

11-1 is a second schematic flowchart of a method for fabricating a temporary substrate provided by another optional embodiment of the present invention;

FIG. 11-2 is a second schematic diagram of a manufacturing process of a temporary substrate provided by another optional embodiment of the present invention;

12-1 is a schematic diagram of a transfer process flow of a micro light-emitting chip provided by another optional embodiment of the present invention;

12-2 is a schematic diagram of a temporary substrate used for chip transfer provided by another optional embodiment of the present invention;

Description of reference numbers:

10- Growth substrate, 11, 31- Epitaxial layer, 12, 32- Electrode, 13, 21- Adhesive glue layer, 131, 211- Adhesive glue layer colloid, 14- Transfer substrate, 20- Substrate body, 22- Blocking layer, 23-chip area, 24-electrode receiving hole, 25-overflow port, 26-expandable material layer, 27-separating wall, 30-bearing substrate, 40-auxiliary substrate.

Detailed ways

In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the related drawings. The preferred embodiments of the present application are shown in the accompanying drawings. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the disclosure of this application is provided.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the present application are for the purpose of describing particular embodiments only, and are not intended to limit the present application.

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 to transfer the micro-LED chip from the first temporary substrate to the display backplane in a similar manner, The adhesive layer set on the first temporary substrate or the second temporary substrate will be deformed to a certain extent by the extrusion of the electrodes of the micro-LED chip, and may contact the epitaxial layer of the micro-LED chip to form a bond, but because it is not completely It is fluid and will not be leveled after bonding with the epitaxial layer. After cooling and fixing, it will make the transfer of the micro-LED chip difficult.

For example, as shown in FIG. 1 , during the process of pressing and embedding the electrodes 12 of the micro light-emitting chips 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 electrodes 12 are pressed and deformed. The colloid 131 is in contact with the epitaxial layer 11 of the micro light-emitting chip to form a bond, which makes the subsequent transfer of the micro light-emitting chip difficult, and even the transfer failure occurs.

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

The temporary substrate exemplified in this embodiment includes a substrate body, an adhesive layer disposed on the substrate body, and a shielding layer disposed on the adhesive layer, and the shielding layer has a plurality of chip regions; There are at least two electrode accommodating holes communicating with the adhesive layer, so that at least two electrodes of the micro light-emitting chip can be inserted into the adhesive layer respectively and form a bond with the adhesive layer, so that the epitaxial layer between the two electrodes of the micro light-emitting chip is formed. It is isolated from the adhesive layer by the shielding layer, which can prevent the adhesive layer from being squeezed and deformed from contact with the epitaxial layer, and in this embodiment, there is an adhesive layer between at least a part of adjacent chip areas The colloid overflows the overflow port, so that the excess part of the colloid that is squeezed overflows from the overflow port, so that the micro light-emitting chip transferred to the temporary substrate only has the electrode and the adhesive layer to form a bond, and other areas are not adhered to the adhesive layer. The adhesive layer is in contact, thereby ensuring the subsequent transfer of the micro light-emitting chip.

It should be understood that, in some application examples of this embodiment, each chip area may have a one-to-one correspondence with a plurality of micro light-emitting chips to be transferred carried on the carrier substrate, or may be set in a non-one-to-one correspondence according to actual requirements. For example, in some application scenarios, the number of micro light-emitting chips to be transferred carried on the carrier substrate may be less than the number of chip areas.

It should be understood that the position and number of the overflow openings in this embodiment can be set flexibly, as long as the squeezed excess colloid can be discharged from the overflow opening and will not come into contact with the micro light-emitting chip. For example, in an application example, an overflow port for the colloid of the adhesive layer to overflow may be provided between all adjacent chip areas on the shielding layer, and in this embodiment, the size and shape of the overflow port may be different. It can be set flexibly 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 it can be a square hole, a circular hole, an oval hole or a hole of any other shape; for example, another In some examples, the overflow can be a through slot.

In other application examples of this embodiment, only a part of adjacent chip regions may be provided with overflow ports for the colloid of the adhesive layer to overflow, for example, N (N greater than or equal to 2) phases may be provided. The adjacent chip area is a chip area group, and an overflow port is set between the adjacent chip area groups. It is also possible to randomly set the overflow port in the area between some adjacent chips, or use other arbitrary rules to set the overflow port in the area between some adjacent chips.

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.

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 an 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.

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 front-mounted LED chip. For example, in one example, the micro-light-emitting chip may be a flip-chip LED chip; In one example, the miniature light-emitting chip may be a front mounted LED chip.

The micro light-emitting chip in this embodiment includes, but is not limited to, an epitaxial layer and electrodes. This embodiment does not limit the specific structure of the epitaxial layer of the micro light-emitting chip. 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 further 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 an example, the material of the electrode may include but not limited to Cr, Ni, Al, Ti, Au, Pt, W, Pb, Rh, Sn, Cu, at least one of Ag.

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

It should be understood that the carrier substrate in this embodiment may be a growth substrate, and the substrate body at this time may be the body of the first temporary substrate; and the material of the growth substrate is various semiconductors that can grow micro light-emitting chips on the growth substrate Material, 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 be understood that the carrier substrate is not limited to the growth substrate, but can also be a first temporary substrate for carrying micro light-emitting chips, and in this case, the temporary substrate in this embodiment can be a second temporary substrate.

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

For ease of understanding, the following description will be made with reference to an example of a temporary substrate arrangement in the accompanying drawings.

An example of setting is shown in FIG. 2-1. An adhesive layer 21 is arranged on the substrate body 20, and a shielding layer 22 is arranged on the adhesive layer 21, wherein the shielding layer 22 has a plurality of chip regions 23. , one chip area 23 corresponds to one micro light-emitting chip on the carrier substrate. Each chip area 23 is provided with two electrode accommodating holes 24 (it should be understood that the number of electrode accommodating holes can be set according to the number of electrodes of the micro light-emitting chip), and overflows are provided between adjacent chip areas 23 Exit 25.

In this example, when the micro light-emitting chips are transferred from the carrier substrate to the temporary substrate, as shown in FIG. 2-2 , the side of the carrier substrate 30 with the micro light-emitting chips and the substrate body 20 are provided with an adhesive layer One side of 21 is attached, and a certain pressure is applied to make the electrodes 32 of the micro light-emitting chip embedded in the adhesive layer 21. During the pressing process, a part of the excess colloid 211 is squeezed to overflow from the overflow port 25, so as to prevent the colloid from overflowing from the adhesive layer 21. The two electrodes of the micro light-emitting chip overflow between the electrodes and form a bond with the epitaxial layer 31 of the micro light-emitting chip, which is more convenient for the subsequent transfer of the micro light-emitting chip from the substrate body 20 .

For another setting example, please refer to FIG. 3-1. An adhesive layer 21 is provided on the substrate body 20, and a blocking layer 22 is provided on the adhesive layer 21, wherein the blocking layer 22 has a plurality of chip areas. 23. One chip area 23 corresponds to one micro light-emitting chip on the carrier substrate. Each chip area 23 is provided with two electrode accommodating holes 24 , and two adjacent chip areas 23 are each set as a chip area group, and an overflow port 25 is provided between the adjacent chip area groups.

In this example, when the micro light-emitting chips are transferred from the carrier substrate to the temporary substrate, as shown in FIG. 3-2 , the side of the carrier substrate 30 with the micro light-emitting chips and the substrate body 20 are provided with an adhesive layer 21, and apply a certain pressure to make the electrodes 32 of the micro light-emitting chip embedded in the adhesive layer 21. During the pressing process, a part of the excess colloid 211 is squeezed to overflow from the overflow port 25, which can also prevent the colloid from overflowing from the adhesive layer 21. The two electrodes of the micro light-emitting chip overflow and form a bond with the epitaxial layer 31 of the micro light-emitting chip.

Optionally, in some examples of this 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 further includes a The expansion material layer, after the electrode is inserted into the electrode accommodating hole and formed into a bond with the adhesive layer, expands under the set expansion environment and forms a close contact with the electrode, which can further improve and ensure that the micro light-emitting chip has only the electrode and the electrode. The adhesive layer forms the bond and no other areas are in contact with the adhesive layer.

The material of the expansion material layer in this embodiment can be made of various materials that can expand under a set expansion environment and do not damage the electrodes. For example, it may be a layer of heat-expandable material or a layer of water-swellable material.

When the material layer is heated to expand, it can be heated to make it expand and form close contact with the electrode, and the heating environment can be an environment for heating and debonding the adhesive layer.

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

It should be understood that the water absorption environment in this embodiment can be set flexibly, as long as the swelling material layer can be swelled by water absorption, so that the degree of close contact between the swelling material layer and the electrode during the swelling process is gradually tighter.

For example, in some examples, the water absorbing environment may be set such that the air humidity is 50% to 100%, and the ambient temperature is normal temperature.

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

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

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;

The pressure is 1.5 standard atmospheres to 2 standard atmospheres, for example, but not limited to, 1.5 standard atmospheres, 1.6 standard atmospheres, 1.7 standard atmospheres, 1.8 standard atmospheres, 2 standard atmospheres, etc.

For ease of understanding, the following description will be made with reference to an example of a temporary substrate arrangement in the accompanying drawings.

An example of setting is shown in FIG. 4-1. An adhesive layer 21 is arranged on the substrate body 20, and a shielding layer 22 is arranged on the adhesive layer 21, wherein the shielding layer 22 has a plurality of chip regions 23. , one chip area 23 corresponds to one micro light-emitting chip on the carrier substrate. Each chip area 23 is provided with two electrode accommodating holes 24 , and at least a part of the two adjacent chip areas 23 is provided with an overflow port 25 . The expanded material layer 26 on the side wall of the electrode accommodating hole 24. After the expanded material layer 26 is provided on the side wall of the electrode accommodating hole 24, the enclosing aperture of the expanded 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 electrodes.

In this example, when the micro light-emitting chips are transferred from the carrier substrate to the temporary substrate, as shown in FIG. 4-2 , an adhesive layer is provided on the side of the carrier substrate 30 with the micro-light-emitting chips and the substrate body 20 . One side of 21 is attached, and then it is placed in an expansion environment and a certain pressure is applied to make the electrode 32 of the micro light-emitting chip 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 overflow between them. During the pressing process, a part of the excess colloid 211 is squeezed and overflowed from the overflow port 25, which can prevent the colloid from overflowing between the two electrodes of the micro light-emitting chip and form bonding with the epitaxial layer 31 of the micro light-emitting chip.

Optionally, in some examples of this 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 overflowing 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. The sum of the heights of the separation wall and the shielding layer is less than or equal to the total height of the micro light-emitting chip minus the electrode embedding adhesive of the micro light-emitting chip. The height of the layer section. The arrangement of the isolation wall can prevent the colloid overflowing from the overflow port from flowing to the chip area, thereby further avoiding the contact between the side of the micro light-emitting chip and the overflowing colloid, and ensuring the subsequent smooth transfer of the micro light-emitting chip.

In some examples of this embodiment, the sum of the heights of the isolation wall and the shielding layer may be equal to the total height of the micro light-emitting chip minus the height of the portion where the electrodes of the micro-light-emitting chip are embedded in the adhesive layer, so that the electrodes of the micro-light-emitting chip are embedded in the adhesive layer. When the height of the embedded adhesive layer reaches a certain level, it can be blocked by the partition wall to prevent it from being further embedded in the adhesive layer. At this time, the partition wall can also play a limiting role.

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

For ease of understanding, the following description will be made with reference to an example of a temporary substrate arrangement in the accompanying drawings.

An example of the arrangement is shown in FIG. 5 , an adhesive layer 21 is arranged on the substrate body 20 , and a shielding layer 22 is arranged on the adhesive layer 21 , wherein the shielding layer 22 has a plurality of chip areas 23 , one The chip area 23 corresponds to a micro light-emitting chip on the carrier substrate. Each chip area 23 is provided with two electrode accommodating holes 24 , and an overflow port 25 is provided between two adjacent chip areas 23 . The expansion material layer 26 on the side wall of the electrode accommodating hole 24 is provided with a partition wall 27 on the shielding layer 22 to isolate each overflow port from the chip area.

In this example, when the micro light-emitting chips are transferred from the carrier substrate to the temporary substrate, as shown in FIG. One side is attached, and then it is placed in an expansion environment and a certain pressure is applied to make the electrode 32 of the micro light-emitting chip 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 passing between the two. overflow. During the pressing process, a part of the excess colloid 211 is squeezed and overflowed from the overflow port 25, and the overflowing colloid 211 is blocked by the partition wall 27 to prevent it from flowing to the chip area, which can prevent the colloid from overflowing from between the two electrodes of the micro light-emitting chip. Bonding is formed with the epitaxial layer 31 of the micro light-emitting chip; and the isolation wall 27 can also prevent the electrodes of the micro light-emitting chip from being excessively embedded in the adhesive layer.

For another setting example, please refer to FIG. 7-1. An adhesive layer 21 is provided on the substrate body 20, and a blocking layer 22 is provided on the adhesive layer 21, wherein the blocking layer 22 has a plurality of chip regions. twenty three. Each chip area 23 is provided with two electrode accommodating holes 24 , and two adjacent chip areas 23 are set as a chip area group, and an overflow port 25 is provided between the adjacent chip area groups. The expansion material layer 26 on the side wall of the electrode accommodating hole 24 is provided with a partition wall 27 on the shielding layer 22 to isolate each overflow port from the chip area. In this example, when the micro light-emitting chips are transferred from the carrier substrate to the temporary substrate, as shown in FIG. 7-2 , an adhesive layer is provided on the side of the carrier substrate 30 with the micro light-emitting chips and the substrate body 20 . One side of 21 is attached, and then it is placed in an expansion environment (such as a heating environment) and a certain pressure is applied to make the electrode 32 of the micro light-emitting chip embedded in the adhesive layer 21, and the expansion material layer 26 is expanded to form close contact with the electrode 32 , to prevent the colloid from overflowing between the two. During the pressing process, a part of the excess colloid 211 is squeezed and overflowed from the overflow port 25, and the overflowing colloid 211 is blocked by the partition wall 27 to prevent it from flowing to the chip area, which can prevent the colloid from overflowing from between the two electrodes of the micro light-emitting chip. Bonding is formed with the epitaxial layer 31 of the micro light-emitting chip; and the isolation wall 27 can also prevent the electrodes of the micro light-emitting chip from being excessively embedded in the adhesive layer.

It should be understood that, in this embodiment, the position of the partition wall 27 on the shielding layer 22 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, please refer to Fig. 8-1 to Fig. 8-2 for an example. Compared with the structures shown in Fig. 7-1 and Fig. 7-2, the main difference is that the partition wall 27 is disposed closer to the electrode accommodating hole. twenty four.

Another optional embodiment of the present invention:

This embodiment provides a method for fabricating the temporary substrate shown in the above embodiments, but it should be understood that the method for fabricating the temporary substrate in this embodiment is only a fabrication example, and the fabrication of the temporary substrate is not limited to method shown in this example. Referring to FIG. 9 , the manufacturing method of the temporary substrate shown in this embodiment includes but is not limited to:

S901: Provide a substrate body.

S902 : forming an adhesive layer on the substrate body.

It should be understood that the material and forming process of the adhesive layer in this embodiment are not limited. For example, the adhesive layer may be formed on the front surface of the substrate body by, but not limited to, coating, printing, and molding.

S903 : forming a shielding layer on the adhesive layer, and the shielding layer has a plurality of chip regions.

The specific material and forming process of the shielding layer are also not limited in this embodiment. For example, in some examples, it can be a metal material or an inorganic material, and the shielding layer can be formed by, but not limited to, deposition, evaporation, etc. .

S904: Form at least two electrode accommodating holes in the chip area that communicate with the adhesive layer, so that at least two electrodes of the corresponding micro light-emitting chip can be inserted respectively and form a bond with the adhesive layer, and at least a part of the electrodes is connected to the adhesive layer. An overflow port for the colloid of the adhesive layer to overflow is formed between adjacent chip areas.

In this embodiment, the formation of the electrode accommodating hole and the overflow port may be formed in the same process step, or may be formed by different process steps. And the formation method used may include, but is not limited to, forming on the shielding layer by etching, cutting, and the like.

Optionally, in this example, in order to prevent the glue from overflowing along the gap between the electrode and the side wall of the electrode accommodating hole during the extrusion process, at least two shielded layers are formed in the chip area and separated from the adhesive glue layer. After the communicating electrode accommodating holes, it can also include but is not limited to:

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 with the adhesive layer, the expansion material layer expands under a set expansion environment to form a close fit with the electrode.

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 with the overflowing 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 separate the overflow from the chip area, 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 electrode embedded in the adhesive layer of the micro light-emitting chip. Wherein, in an example, after forming an overflow port for the colloid of the adhesive layer to overflow between at least a part of the adjacent chip areas, the method may further include: forming an overflow port on the shielding layer to isolate the overflow port from the chip area. The isolation wall, the height of the isolation wall is less than or equal to the total height of the micro light-emitting chip minus the height of the part where the electrodes of the micro-light-emitting chip are embedded in the adhesive layer.

In other examples of this embodiment, the separation wall may also be formed simultaneously with the process of forming the overflow.

For ease of understanding, this embodiment is described below with reference to the two methods for fabricating temporary substrates shown in FIG. 10 and FIG. 11 as examples.

A fabrication method of a temporary substrate is shown in FIGS. 10-1 to 10-2, including but not limited to:

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

The shielding layer 22 can be, but not limited to, a hard metal layer or a hard inorganic layer.

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

It should be understood that step S1001 and S1002 may be performed simultaneously, or S1001 may be performed first, and then S1002 may be performed, or S1002 may be performed first, and then S1001 may be performed.

S1003 : decompressing and bonding the surface of the auxiliary substrate 40 on which the shielding layer 22 is provided with the adhesive layer 21 on the substrate body 20 under high temperature.

In this step, the shielding layer 22 is bonded to the adhesive layer, and at the same time, because the shielding layer 22 has a good plane shape, the adhesive layer 21 can be flattened under a certain pressure.

S1004: Remove the auxiliary substrate 40.

The auxiliary substrate 20 can be removed to expose the shielding layer 22 through, but not limited to, physical grinding, plasma etching, chemical etching, etc. Optionally, the thickness of the shielding layer 22 can be reserved with a certain margin to prevent the auxiliary substrate 20 from being removed. As a result, the thickness of the shielding layer 22 is insufficient.

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

For example, the shielding layer 22 can be formed into a pattern with electrode accommodating holes 24 and overflow openings 25 by, but not limited to, photolithography and etching, and the shielding layer 22 leaves electrode accommodating holes 24 corresponding to the electrodes of the micro light-emitting chip. The electrode accommodating holes The pattern of 24 is the same as that of 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, there is an opening between the chip regions corresponding to the adjacent micro-light-emitting chip as the overflow port 25, and the shape is not limited.

S1006 : forming the expansion material layer 26 in the electrode receiving hole 24 and the overflow port 25 on the shielding layer 22 .

S1007: Remove the middle area of the expansion material layer 26 in the electrode receiving hole 24, keep the expansion material layer 26 on the side wall of the electrode receiving hole 24; and remove all the expansion material layer 26 in the overflow port.

For example, the expansion material layer 26 can be formed in the electrode accommodating hole 24 by coating, photolithography, etc., which has a larger thermal expansion coefficient or water absorption expansion coefficient. After the buffer is formed, the expansion material layer 26 encloses the formed opening. The aperture is slightly larger than the size of the electrodes of the micro light-emitting chip.

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

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.

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 .

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.

In this example, if the organic material used in the material layer of the isolation wall 27 is already a photoresist material with photosensitivity, it is sufficient to directly perform photolithography to form a pattern, and there is no need to perform etching or the like.

Please refer to Fig. 11-1 to Fig. 11-2 for another fabrication method of the temporary substrate, which includes but is not limited to:

S1101: Form a hard shielding layer 22 on the auxiliary substrate 40 by deposition (eg physical vapor deposition) or evaporation.

The shielding layer 22 can 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 The electrode is to be pressed into the glue material depth).

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

It should be understood that step S1101 and S1102 may be performed simultaneously, or S1101 may be performed first, and then S1102, or S1102 may be performed first, and then S1101 may be performed.

S1103: Decompressing and bonding the surface of the auxiliary substrate 40 on which the shielding layer 22 is provided with the adhesive layer 21 on the substrate body 20 by high temperature decompression.

In this step, the shielding layer 22 and the adhesive layer are bonded together. At the same time, because the shielding layer 22 has a good plane shape, the adhesive layer 21 can be flattened under a certain pressure.

S1104: Remove the auxiliary substrate 40.

The auxiliary substrate 20 can be removed to expose the shielding layer 22 through, but not limited to, physical grinding, plasma etching, chemical etching, etc. Optionally, the thickness of the shielding layer 22 can be reserved with a certain margin to prevent the auxiliary substrate 20 from being removed. As a result, the thickness of the shielding layer 22 is insufficient.

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

For example, the shielding layer 22 can be formed into a pattern with electrode accommodating holes 24, overflow ports 25 and shielding walls 27 by, but not limited to, photolithography and etching, and the shielding layer 22 leaves electrode accommodating holes 24 corresponding to the electrodes 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. The height of the formed isolation wall 27 plus the height of the blocking 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.

S1106 : forming the expansion material layer 26 in the electrode receiving hole 24 and the overflow port 25 on the shielding layer 22 .

S1107: Remove the middle area of the expansion material layer 26 in the electrode receiving hole 24, keep the expansion material layer 26 on the side wall of the electrode receiving hole 24; and remove all the expansion material layer 26 in the overflow port.

For example, the expansion material layer 26 can be formed in the electrode accommodating hole 24 by coating, photolithography, etc., which has a larger thermal expansion coefficient or water absorption expansion coefficient. After the buffer is formed, the expansion material layer 26 encloses the formed opening. The aperture is slightly larger than the size of the electrodes of the micro light-emitting chip.

Another optional embodiment of the present invention:

This embodiment also provides a method for transferring a micro light-emitting chip, including:

Align and press the side of the carrier substrate carrying a plurality of micro-light-emitting chips to be transferred with the side of the temporary substrate provided with the adhesive layer, and each electrode of the micro-light-emitting chip is inserted into the corresponding The electrode accommodating hole is embedded in the adhesive layer, and a part of the colloid squeezed by the adhesive layer during the pressing process overflows through the overflow outlet;

The carrier substrate is separated from the micro light-emitting chip, and the transfer of the micro light-emitting chip to the temporary substrate is completed.

For ease of understanding, this embodiment is described below with reference to a transfer example, please refer to FIG. 12-1 to FIG. 12-2 , which include but are not limited to:

S1201 : generating micro light-emitting chips on the carrier substrate 30 .

The carrier substrate 30 in this example 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 the first temporary substrate, and the temporary substrate 20 may be the second temporary substrate.

S1202: Laminating the side of the carrier substrate 30 on which the micro light-emitting chips are grown with the side of the temporary substrate 20 provided with the shielding layer 22 in an example.

The carrier substrate 30 and the temporary substrate 20 are aligned and bonded, 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 closely attached 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 layer 21 Among the glue materials, the extruded glue material will not protrude from both sides of the micro light-emitting chip or in front of the two electrodes of the micro light-emitting chip due to the blocking layer 22, but will be extruded from the overflow port, thereby avoiding the need for glue. At the same time, the existence of the separation wall 27 prevents the electrode 32 of the micro light-emitting chip from being pressed into the adhesive layer to an abnormal depth even if the pressure is too large, and the separation wall 27 is wrapped around the overflow port to prevent extrusion The extruded glue material flows around the micro light-emitting chip, and the space volume enclosed by the partition wall 27 only needs to ensure that the height of the extruded glue material cannot touch the carrier substrate 30 .

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

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 made of a water-absorbing expansion material, it can be dehydrated by heating or the like to return to its original size). Affect the subsequent transfer of the micro light-emitting chip; and then transfer the micro light-emitting chip from the temporary substrate to other substrates or transfer and weld it to a specific position on the backplane by weakening the structure, transfer head transfer, etc.

It should be noted that the transfer method for micro light-emitting chips provided in this application is not only applicable to micro light-emitting chips, but also to other micro-chips with similar transfer processes, and also to light-emitting chips of ordinary size that need to be transferred.

It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above descriptions, and all these improvements and transformations should belong to the protection scope of the appended claims of the present invention.

Claims (10)

1. A temporary substrate, characterized in that, comprising: substrate body; an adhesive layer disposed on the substrate body; A shielding layer disposed on the adhesive layer, the shielding layer has a plurality of chip areas; the chip area is provided with at least two electrode accommodating holes communicated with the adhesive layer for micro At least two electrodes of the light-emitting chip are respectively inserted and bonded with the adhesive layer; at least a part of the adjacent chip regions are provided with overflow ports for the colloid of the adhesive layer to overflow. 2 . The temporary substrate according to claim 1 , wherein all adjacent chip regions are provided with overflow ports for the colloid of the adhesive layer to overflow. 3 . 3. The temporary substrate of claim 1, wherein 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, wherein the temporary substrate further comprises an intumescent material layer disposed on the sidewall of the electrode receiving hole, the intumescent material layer in the After the electrode is inserted into the electrode accommodating hole and forms a bond with the adhesive layer, it expands under a set expansion environment, and is closely attached to the electrode. 5 . The temporary substrate of claim 4 , wherein the expansion material layer is a heat expansion material layer or a water absorption expansion material layer. 6 . 6 . The temporary substrate according to claim 1 , wherein the temporary substrate further comprises an isolation wall disposed on the shielding layer to isolate the overflow port from the chip area. 7 . 7. A method for making a temporary substrate, comprising: forming an adhesive layer on the substrate body; forming a shielding layer on the adhesive layer, the shielding layer has a plurality of chip areas; At least two electrode receiving holes communicated 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 with the adhesive layer, and at least two electrodes of the micro light-emitting chip can be inserted into the adhesive layer. An overflow port for the colloid of the adhesive layer to overflow is formed between a part of the adjacent chip regions. 8 . The manufacturing method of the temporary substrate according to claim 7 , wherein after the forming at least two electrode receiving holes in the chip area that communicate with the adhesive layer, the method further comprises: 9 . An expansion material layer is formed on the side wall of the electrode accommodating hole, and the expansion material layer is formed under a set expansion environment after the electrode is inserted into the electrode accommodating hole and forms a bond with the adhesive layer. expand and fit tightly with the electrode. 9 . The manufacturing method of the temporary substrate according to claim 7 , wherein after forming an overflow port for the colloid of the adhesive layer to overflow between at least a part of the adjacent chip regions. 10 . ,Also includes: A separation wall is formed on the shielding layer to isolate the overflow port from the chip area. 10. A method for transferring miniature light-emitting chips, comprising: Align and press the side of the carrier substrate carrying the micro-light-emitting chips to be transferred with the side of the temporary substrate provided with the adhesive layer according to any one of claims 1-6. Each electrode of the micro light-emitting chip is respectively inserted into the corresponding electrode accommodating hole and embedded in the adhesive layer, and a part of the colloid squeezed by the adhesive layer during the pressing process overflows through the overflow port; The carrier substrate is separated from the micro light-emitting chip, and the transfer of the micro light-emitting chip to the temporary substrate is completed.

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