Temporary substrate, manufacturing method, and mass transfer method

Abstract

The present application relates to a kind of temporary storage substrate, manufacturing method and mass transfer method.The present application provides a kind of temporary storage substrate, comprising: first substrate;And elastic layer, the elastic layer is arranged on the first substrate, and the elastic layer includes multiple groove units;Wherein, the groove in the groove unit is used to accommodate the electrode of a light emitting diode chip, and the size of at least part of the groove is less than or equal to the size of the electrode.The present application can be by the elastic force generated by the cooperation of groove unit and the electrode of light emitting diode chip, to provide fixing force for temporary storage substrate.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more particularly to temporary storage substrates, manufacturing methods, and mass transfer methods. Background Technology

[0002] In the manufacturing process of micro-LED chips, the LED chips on the growth substrate need to be transferred and bonded to a temporary substrate. The temporary substrate provides a fixing force for the LED chips through bonding. The transfer substrate is used to transfer the LED chips from the temporary substrate to the backplane. The fixing force between the temporary substrate and the LED chips affects the transfer yield of the LED chips. The fixing force on the temporary substrate is related to the performance of the adhesive material used. Therefore, it is not easy to control the fixing force between the LED chips and the temporary substrate. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this application is to provide a temporary storage substrate, a manufacturing method and a mass transfer method, which aims to solve the problem of inconvenience in controlling the fixing force between the light-emitting diode chip and the temporary storage substrate.

[0004] This invention provides a temporary storage substrate, comprising:

[0005] A first substrate; and an elastic layer disposed on the first substrate, the elastic layer comprising a plurality of trench units; wherein trenches in the trench units are used to accommodate electrodes of a light-emitting diode chip, and at least a portion of the trenches have dimensions less than or equal to the dimensions of the electrodes.

[0006] Optionally, the light-emitting diode chip includes an electrode on the side near the elastic layer, and the trench unit includes a trench; the size of the trench is less than or equal to the size of the electrode.

[0007] Optionally, the light-emitting diode chip includes at least two electrodes on the side near the elastic layer, and the at least two electrodes are housed in a trench unit, wherein the size of at least one trench is less than or equal to the size of the electrode.

[0008] Optionally, the trench with a size less than or equal to the size of the electrode has a length in a first direction less than or equal to the length of the electrode in the first direction; wherein, the first direction includes a direction parallel to the plane of the first substrate.

[0009] Optionally, the trench with a size less than or equal to the size of the electrode has a length in the second direction less than or equal to the length of the electrode in the second direction; wherein the second direction includes a direction parallel to the plane of the first substrate, and the second direction intersects the first direction.

[0010] Optionally, the trench with a size less than or equal to the size of the electrode has its projection onto the plane of the first substrate located within the projection of the corresponding electrode onto the plane of the first substrate.

[0011] Optionally, the minimum trench spacing between adjacent trench units is greater than the distance between adjacent trenches within the same trench unit.

[0012] Optionally, the grooves divide the elastic layer into multiple independent island-like structures, and the edges of the island-like structures are designed to be rounded and / or chamfered.

[0013] Based on the same inventive concept, the present invention provides a method for manufacturing a temporary storage substrate, comprising:

[0014] A second substrate is provided, and the second substrate is etched to form multiple protrusions;

[0015] A first substrate is provided, and an elastic solution is coated on the first substrate;

[0016] The first substrate is imprinted using the second substrate, and a plurality of trench units are formed on the first substrate, wherein the trenches in the trench units are used to accommodate the electrodes of a light-emitting diode chip, and at least a portion of the trenches have a size less than or equal to the size of the electrodes.

[0017] Optionally, the step of providing a second substrate and etching the second substrate to form a plurality of protrusions includes:

[0018] A photoresist layer is coated on the second substrate and photolithography is performed to form multiple photoresist units;

[0019] The second substrate is etched using the photoresist unit as a mask to form multiple protrusions.

[0020] Based on the same inventive concept, the present invention provides a mass transfer method, comprising:

[0021] A temporary storage substrate is provided, the temporary storage substrate including a first substrate and an elastic layer, the elastic layer being disposed on the first substrate, and the elastic layer including a plurality of trench units, wherein the trenches in the trench units are used to accommodate electrodes of a light-emitting diode chip, and at least a portion of the trenches have a size less than or equal to the size of the electrodes;

[0022] A growth substrate is provided, on which a plurality of light-emitting diode chips are disposed;

[0023] The temporary storage substrate is placed above the growth substrate, and the temporary storage substrate is aligned with the growth substrate.

[0024] Pressure is applied from one side of the temporary substrate and / or the growth substrate to cause the electrode to be engaged in at least a portion of the trench with a size smaller than or equal to that of the electrode under the action of the elastic layer;

[0025] The growth substrate is peeled off.

[0026] Optional, also includes:

[0027] Each of the light-emitting diode chips on the temporary storage substrate is transferred and bonded to a backplane.

[0028] In the temporary storage substrate, manufacturing method and mass transfer method provided by the present invention, the elastic force generated by the cooperation between the trench unit and the electrode unit of the light-emitting diode chip can be used to provide a fixing force for the temporary storage substrate.

[0029] The fixing force of the temporary substrate can be controlled by controlling the elastic deformation and elastic modulus when the trench unit matches the electrode unit of the light-emitting diode chip.

[0030] By reducing the number of bonding and debonding processes during the transfer, the uniformity of LED chip quality can be ensured. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a temporary storage substrate in one embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of a temporary storage substrate in one embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram of the structure of a trench unit in one embodiment of the present invention.

[0034] Figure 4 This is a schematic diagram of the structure of a trench unit in one embodiment of the present invention.

[0035] Figure 5 This is a schematic diagram of a temporary substrate manufacturing method according to an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the second substrate in one embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of the photoresist layer in one embodiment of the present invention;

[0038] Figure 8 This is a schematic diagram of a photoresist unit in one embodiment of the present invention;

[0039] Figure 9 This is a schematic diagram of a protrusion in one embodiment of the present invention;

[0040] Figure 10 This is a schematic diagram of the first substrate in one embodiment of the present invention;

[0041] Figure 11 This is a schematic diagram of an elastic solution in one embodiment of the present invention;

[0042] Figure 12 This is a schematic diagram of the second substrate imprinting onto the first substrate in one embodiment of the present invention;

[0043] Figure 13 This is a schematic diagram of a mass transfer method in one embodiment of the present invention;

[0044] Figure 14 This is a schematic diagram of the growth substrate in one embodiment of the present invention;

[0045] Figure 15 This is a schematic diagram showing the connection between the electrodes of the light-emitting diode chip and the trench in one embodiment of the present invention;

[0046] Figure 16 This is a schematic diagram illustrating the separation of the growth substrate from the light-emitting diode chip in one embodiment of the present invention;

[0047] Figure 17 This is a schematic diagram of a mass transfer method in one embodiment of the present invention;

[0048] Figure 18 This is a schematic diagram of the bonding between a light-emitting diode chip and a backplane in one embodiment of the present invention.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-First substrate; 2-Elastic layer; 20-Elastic solution; 21-Trench unit; 210-Trench; 22-Rounded corner; 3-First direction; 4-Second substrate; 41-Protrusion; 5-Photoresist layer; 51-Photoresist unit; 6-Light emission diode chip; 60-Electrode unit; 61-Electrode; 7-Growth substrate; 8-Backplane; 81-Pad. Detailed Implementation

[0051] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0053] In the manufacturing process of Micro LED or Mini LED, for example, the LED chip is transferred from the growth substrate to a temporary storage substrate and temporarily stored. This facilitates the subsequent transfer of the LED chip to the driving circuitry on the backplane via a transfer substrate. On the temporary storage substrate, the LED chip is fixed, for example, with an adhesive material. The fixing force is determined by the material properties of the adhesive, making it difficult to control. Figure 1 As shown, the present invention provides a temporary storage substrate to improve the fixing force of the temporary storage substrate. The temporary storage substrate includes: a first substrate 1 and an elastic layer 2.

[0054] like Figure 1 As shown, the elastic layer 2 is disposed on the first substrate 1, and the elastic layer 2 includes a plurality of trench units 21, wherein the trenches 210 of the trench units 21 are used to accommodate the electrodes of a light-emitting diode chip, and at least a portion of the trenches 210 have a size smaller than or equal to the size of the electrodes. When the light-emitting diode chip on the growth substrate is transferred to the temporary storage substrate, by aligning and engaging the electrodes with the trench units 21, when the size of at least a portion of the trenches 210 is equal to that of the electrodes, the trenches 210 accommodate the electrodes, restricting the degree of freedom of the electrodes, thereby fixing the light-emitting diode chip on the temporary storage substrate. The size of the trenches 210 can also be adjusted. For example, when the size of at least a portion of the trenches 210 is smaller than that of the electrodes, the trenches 210 and the electrodes are engaged, for example, with a clearance fit or an interference fit. Due to the elastic deformation of the trenches 210 and the corresponding elastic layer 2, elastic force is generated, which restricts the light-emitting diode chip. The degree of freedom of the substrate enables the temporary storage substrate to fix the light-emitting diode chip. The size of the elastic force can be controlled by changing the size of the trench 210 that mates with the electrode, thereby adjusting the fixing force of the temporary storage substrate. For example, in the trench unit 21 that mates with the electrode, at least some of the trenches 210 have a size smaller than or equal to the size of the electrode, while the size of other trenches 210 can be larger than the size of the electrode. This ensures that at least some of the trenches 210 in the trench unit 21 that mates with the electrode have a size smaller than or equal to the size of the electrode. The electrode is attached to the trench 210, which can provide a fixing force for supporting the light-emitting diode.

[0055] like Figure 3As shown, the light-emitting diode chip includes an electrode 61 on the side near the elastic layer 2. At this time, the corresponding trench unit 21 has a trench. The size of the trench 210 is smaller than or equal to the size of the electrode. For example, the size of the electrode 61 is equal to the size of the trench unit 21. The electrode 61 cooperates with the trench unit 21. When the posture of the electrode 61 changes, the trench 210 in the trench unit 21 will generate elastic deformation and elastic force, thereby restricting the degree of freedom of the electrode 61 and achieving the purpose of fixing the electrode 61. For another example, the size of the electrode 61 is larger than the size of the trench unit 21. The electrode 61 cooperates with the trench unit 21, and the trench unit 21 will generate elastic deformation and elastic force, thereby providing a fixing force to fix the electrode 61 on the temporary substrate.

[0056] like Figure 4 As shown, the light-emitting diode chip includes at least two electrodes 61 on the side near the elastic layer. These at least two electrodes 61 are housed in a trench unit 21. In the trench unit 21, the size of at least one trench 210 is less than or equal to the size of the electrode 61. Exemplarily, at least two electrodes 61 can form an electrode unit 60, where the number of trenches 210 in the trench unit 21 is the same as the number of electrodes 61 in the electrode unit 60, and the size of at least one trench 210 in the trench unit 21 is less than or equal to the size of the electrode 61. For example, the trench unit 21 includes two trenches, and the electrode unit 60 includes two electrodes 61, with the polarities of the two electrodes 61 being positive and negative, respectively. For example, the size of the electrode 61 in the electrode unit 60 is equal to the size of the trench 210 in the trench unit 21. The electrode unit 60 cooperates with the trench unit 21. When the orientation of the electrode 61 in the electrode unit 60 changes, the trench 210 in the trench unit 21 will generate elastic deformation and elastic force, thereby restricting the degree of freedom of the electrode 61 in the electrode unit 60 and achieving the purpose of fixing the electrode 61 in the electrode unit 60. For example, the size of the electrode 61 in the electrode unit 60 is larger than the size of the trench 210 in the trench unit 21, and the electrode 61 in the electrode unit 60 and the trench 210 in the trench unit 21 interact. In a combined relationship, the trenches 210 and corresponding elastic layers in the trench unit 21 will generate elastic deformation and elastic force, which fixes the electrode unit 60 to the temporary substrate through a fixing force. For example, in the trench unit 21, at least one trench 210 is smaller than the electrode. By changing the size of the trench 210, the elastic deformation and elastic force between the trench 210 and the electrode 61 are adjusted, thereby controlling the magnitude of the fixing force on the temporary substrate. Another example is that in the trench unit 21, at least one trench 210 is smaller than the electrode 210, while the other trenches 210 are larger than the electrode 210. The trenches 210 smaller than the electrode 210 hold the electrode 210 within the trench 210, thereby providing a fixing force to support the light-emitting diode. Figure 1 As shown, when the LED chip requires a large fixing force, the size of the trench 210 can be reduced, or the elastic layer 2 can be made of a material with a large elastic modulus. Therefore, when the trench 210 and the electrodes of the LED chip undergo elastic deformation, a larger fixing force can be generated, meeting the requirements for the fixing force of the temporary storage substrate. For example, when the LED chip requires a smaller fixing force to avoid the transfer substrate needing to overcome a large fixing force to transfer the LED chip, the size of the trench unit 21 can be increased, or the elastic layer 2 can be made of a material with a small elastic modulus. Therefore, when the trench unit 21 and the electrode unit of the LED chip undergo elastic deformation, a suitable fixing force is generated. Alternatively, depending on the required fixing force, the elastic layer 2 can be made of a material with a suitable elastic modulus. The deformation and size of the trench 210 can also be determined based on the elastic modulus of the material, increasing the threshold range of the fixing force provided by the trench 210 and facilitating control of the fixing force provided by the temporary storage substrate.

[0057] like Figure 2 As shown, to guide the alignment and mating of the LED chip on the growth substrate with the temporary storage substrate, the trench 210 divides the elastic layer 2 into multiple independent island-like structures, and the edges of the island-like structures are designed as rounded arcs and / or chamfers. For example, the rounded arcs and / or chamfers are provided on the island-like structures to guide the mating end of the LED chip. In some embodiments, the island-like structures may include rounded corners 22 to reduce the constraint force during the mating process between the electrodes of the LED chip and the trench 210, and to avoid inconsistencies or tilting of the LED chip on the temporary storage substrate due to deviations in constraint force.

[0058] In some embodiments, the trench, whose size is less than or equal to the size of the electrode, has a length in a first direction that is less than or equal to the length of the electrode in the first direction; wherein, the first direction includes a direction parallel to the plane containing the first substrate. Figure 1Alternatively, as shown in diagram 4, to accommodate the trench 210 and the electrode 61 of the LED chip, the length of the trench 210 in the first direction 3 is less than or equal to the length of the electrode 61 in the first direction 3. The first direction 3 includes a direction parallel to the plane of the first substrate 1. For example, the length of the trench 210 in the first direction 3 is 'a', and the length of the electrode 61 of the LED chip, which matches the trench 210, in the first direction 3 is 'b', where a ≤ b. The first direction 3 includes a direction parallel to the plane of the first substrate 1. For example, if the size of the electrode 61 of the LED chip is larger than that of the trench 210, then when the temporary storage substrate carries the LED chip, it will be constrained by the elastic force of the trench 210, achieving the purpose of fixing the LED chip on the temporary storage substrate. Alternatively, if the size of the electrode 61 of the LED chip is equal to that of the trench 210, then when the orientation of the electrode 61 changes, the trench 210 will undergo elastic deformation, thereby constraining the orientation of the electrode through elastic force, achieving the purpose of fixing the LED chip on the temporary storage substrate.

[0059] like Figure 1 As shown, in some embodiments, the trench 210, whose size is less than or equal to the size of the electrode, has a length in a second direction that is less than or equal to the length of the electrode in the second direction; wherein, the second direction includes a direction parallel to the plane of the first substrate 1, and the second direction intersects the first direction 3. For example, the second direction is perpendicular to the first direction 3, and in the second direction, the length of the trench 210 is less than or equal to the length of the electrode in the second direction. During the assembly process of the trench 210 and the electrode, the trench 210 and the elastic layer 2 deform, which can hold the electrode in the trench 210, thereby providing a fixing force for supporting the light-emitting diode chip.

[0060] In some embodiments, the trench, whose size is less than or equal to that of the electrode, has its projection onto the plane of the first substrate located within the projection of the corresponding electrode onto the plane of the first substrate. Exemplarily, the size of the trench can be controlled in multiple directions to generate an elastic force to secure the electrodes of the LED chip, such that the projection of the trench onto the plane of the first substrate is located within the projection of the corresponding electrode onto the plane of the first substrate, thereby engaging the electrode within the trench and providing a fixing force to support the LED.

[0061] In some embodiments, the minimum trench spacing between adjacent trench units is greater than the distance between adjacent trenches within the same trench unit, such as... Figure 1As shown, the distance between adjacent trenches 210 in the same trench unit 21 is less than or equal to the minimum trench spacing between adjacent trenches 210 in two adjacent groups of trench units 21. For example, in the same trench unit 21, the distance between two adjacent trenches 210 is l1; in two groups of trench units 21, the minimum trench spacing between adjacent trench units is l2, and l2 ≥ l1. The spacing between adjacent trenches can be set according to the arrangement of the LED chips to be transferred. In the same group of trench units, the distance between two adjacent trenches 210 is l1, which matches the size of the LED chips. In two groups of trench units 21, the minimum trench spacing between adjacent trenches 210 is l2, which matches the spacing between adjacent LED chips, satisfying: l2 ≥ l1.

[0062] like Figure 1 As shown, in some embodiments, the temporary storage substrate may include multiple trench units 21 of different types and / or sizes to temporarily store LED chips of different types and sizes. For example, when the temporary storage substrate needs to temporarily store LED chips of different sizes, different trench units 21 are provided on the substrate 1. The trenches 210 in the trench units 21 have different sizes and are matched with the corresponding LED chips respectively, so as to satisfy the elastic deformation of the trenches 210 and fix the electrodes of the LED chips. For example, when the temporary storage substrate needs to temporarily store different types of LED chips, different trench units 21 are provided on the substrate 1. The number and size of the trenches 210 in the trench units 21 are different and are matched with the corresponding LED chips respectively, so as to satisfy the requirements of elastic deformation and elastic force of the trenches 210 and fix the electrode units of the LED chips.

[0063] In some embodiments, to adjust the fixing force of the temporary substrate on the light-emitting diode chip, materials with different elastic moduli can be selected as the materials for the elastic layer and the trench. For example, the material of the elastic layer includes polydimethylsiloxane (PDMS). PDMS has low surface tension and certain adsorption force, which meets the requirements for supporting and fixing the light-emitting diode chip. For example, the material of the elastic layer includes polymethyl methacrylate (PMMA). For example, the material of the elastic layer includes polyimide (PI), a type of polymer containing imide rings (-CO-N-CO-) on its main chain, which is an elastic organic polymer material. For example, the material of the elastic layer includes polyurethane (PU), a polymer containing repeating -HNCOO- structural units on its main chain. It is generally formed by addition polymerization of polyisocyanates and polyol polymers. The ratio of NCO to OH in the polymer can also be changed to obtain polyurethane with certain elasticity, thermosetting properties, thermoplasticity, and good insulation.

[0064] like Figures 5 to 12 As shown, the present invention also provides a method for manufacturing a temporary storage substrate, comprising:

[0065] S1: Provide a second substrate 4, and etch the second substrate 4 to form a plurality of protrusions 41;

[0066] S2: Provide a first substrate 1, and coat the first substrate 1 with an elastic solution 20;

[0067] S3: Imprinting the first substrate 1 onto the second substrate 4 and forming a plurality of trench units on the first substrate 1, wherein the trenches in the trench units are used to accommodate the electrodes of a light-emitting diode chip, and at least a portion of the trenches have a size less than or equal to the size of the electrodes.

[0068] like Figure 6 and Figure 10As shown, in step S1, for example, the second substrate 4 can be a silicon substrate, which can be etched using a chemical method to form multiple bumps 41. In some embodiments, the etching process can be controlled according to the type and size of the light-emitting diode chip to adjust the size and arrangement of the formed bumps. For example, plasma sputtering can be used for etching, for example, sulfur hexafluoride (SF6) can be selected as the etching gas and carbon octafluoride (C4F8) can be selected as the passivation gas. Carbon octafluoride (C4F8) is first introduced for passivation, and then sulfur hexafluoride (SF6) is introduced for etching. The two gases are introduced alternately, and the radio frequency power, chamber pressure and gas flow rate are set to finally form multiple bumps 41. Before providing the second substrate 4, the second substrate can also be cleaned, for example, by ultrasonic cleaning with organic solvents such as deionized water, acetone and isopropanol, and then dried with nitrogen.

[0069] like Figure 10 and 11 As shown, in step S2, for example, an elastic solution 20 is coated on a first substrate 1, and grooves are formed on the elastic solution 20 by a nanoimprinting process.

[0070] like Figure 1 and 12 As shown, in step S3, for example, the first substrate 1 and the elastic solution are imprinted by the second substrate 4 with protrusions 41, so that the elastic solution changes shape under the action of the protrusions 41 to form a plurality of groove units 21. For example, during the imprinting process of the elastic solution, the groove units 21 are matched with the electrode units of the light-emitting diode chip.

[0071] like Figure 7 , 8 As shown in Figure 9, in some embodiments, the steps in step S1 include:

[0072] A photoresist layer 5 is coated on the second substrate 4 and photolithography is performed to form a plurality of photoresist units 51;

[0073] The second substrate 4 is etched using the photoresist unit 51 as a mask to form a plurality of the protrusions 41.

[0074] like Figure 1 and 7 As shown, the steps for forming the photoresist unit 51 include: for example, completing photolithography through a photolithography process, or for example, irradiating the exposure area of ​​the photoresist layer 5 through a mask, cleaning and retaining the photoresist unit 51, wherein the mask pattern of the mask corresponds to the arrangement and electrode size of the light-emitting diode chip to be transferred.

[0075] like Figure 8 and 9As shown, the second substrate 4 is etched using the photoresist unit 51 as a mask to form multiple protrusions 41. Since the photoresist unit 51 is attached to the surface of the second substrate 4, under the action of etching, the photoresist unit 51 will absorb the etching energy and decompose, while the area not covered by the photoresist unit 51 will be directly etched, thereby forming the protrusions 41.

[0076] like Figure 1 and 2 As shown, the trench 210 divides the elastic layer 2 into multiple independent island-like structures, and the edges of the island-like structures are rounded and / or chamfered. To facilitate the guidance of the electrode units of the light-emitting diode chip into the trench unit, the method further includes the following after step S1:

[0077] The edges of the island-like structure are etched to form rounded arcs and / or chamfers.

[0078] The trench 210 may include an arc 22 to prevent jamming during the mating of the LED chip's electrodes with the trench 210. For example, the arc and / or chamfer are provided on the island structure to guide one end of the LED chip. In some embodiments, the island structure may include rounded corners to reduce the constraint force during the mating of the LED chip's electrodes with the trench unit, thus preventing inconsistencies or tilting of the LED chip on the temporary storage substrate due to deviations in constraint force.

[0079] like Figure 11 As shown, in order to adjust the fixing force of the temporary substrate on the light-emitting diode chip, materials with different elastic moduli can be selected as solvents for the elastic solution 20. For example, the solvent material of the elastic solution 20 includes polydimethylsiloxane (PDMS). Polydimethylsiloxane has low surface tension and certain adsorption force, which meets the requirements for supporting and fixing the light-emitting diode chip. For example, the solvent material of the elastic solution 20 includes polymethyl methacrylate (PMMA). For example, the solvent material of elastic solution 20 includes polyimide (PI), a type of polymer containing an imide ring (-CO-N-CO-) in its main chain, which is an elastic organic polymer material. Another example is polyurethane (PU), a polymer containing repeating -HNCOO- structural units in its main chain. It is generally formed by addition polymerization of polyisocyanates and polyol polymers. The ratio of NCO to OH in the polymer can also be changed to obtain polyurethane with certain elasticity, thermosetting properties, thermoplasticity and good insulation properties.

[0080] After the LED chip manufacturing process is completed, the LED chip on the growth substrate is transferred to a temporary storage substrate for temporary storage. However, the fixing force of the temporary storage substrate is related to the material properties of the adhesive, making it difficult to control the fixing force of the temporary storage substrate on the LED chip. Figures 13 to 16 The present invention also provides a mass transfer method, comprising:

[0081] S10: A temporary storage substrate is provided, the temporary storage substrate includes a first substrate 1 and an elastic layer, the elastic layer is disposed on the first substrate 1, and the elastic layer includes a plurality of trench units, wherein the trenches in the trench units are used to accommodate the electrodes of a light-emitting diode chip, and at least a portion of the trenches have a size less than or equal to the size of the electrodes.

[0082] S20: A growth substrate 7 is provided, on which a plurality of light-emitting diode chips 6 are disposed;

[0083] S30: Place the temporary storage substrate above the growth substrate and control the temporary storage substrate to complete the alignment with the growth substrate;

[0084] S40: Apply pressure from one side of the temporary storage substrate and / or the growth substrate to cause the electrode to be engaged in at least a portion of the trench with a size smaller than or equal to that of the electrode under the action of the elastic layer;

[0085] S50: Peel off the growth substrate.

[0086] Please see Figure 14 In step S10, multiple trench units are used to support and fix the light-emitting diode chip 6 transferred from the growth substrate 7. The trench units in the trench units are matched with the electrodes of the corresponding light-emitting diode chips. When the light-emitting diode chips on the growth substrate are transferred to the temporary storage substrate, the electrodes are aligned and matched with the electrodes in the trench units. When the size of the trench in the trench unit is equal to that of the electrode, the trench accommodates the electrode and restricts the degree of freedom of the electrode, thereby fixing the light-emitting diode chip on the temporary storage substrate. The size of the trench can also be adjusted. For example, when the size of the trench is smaller than that of the electrode, the trench and the electrode are matched. Due to the elastic deformation of the trench, an elastic force is generated, thereby fixing the light-emitting diode chip on the temporary storage substrate. The size of the elastic force can also be controlled by changing the size of the trench, thereby adjusting the fixing force of the temporary storage substrate.

[0087] Please see Figure 14 and Figure 15In step S30, the growth substrate 7 is moved to a position corresponding to the temporary storage substrate and then aligned. In step S40, pressure is applied from one side of the temporary storage substrate and / or the growth substrate to cause the electrode to be engaged in at least a portion of the trench with a size smaller than or equal to that of the electrode under the action of the elastic layer.

[0088] like Figure 16 As shown, in step S50, for example, the growth substrate 7 can be peeled off by laser lift-off (LLO) technology, and the gallium nitride at the connection between the light-emitting diode chip 6 and the growth substrate 7 can be decomposed by laser energy, thereby completing the engagement of the electrode 61 of the light-emitting diode chip with the temporary substrate and fixing the light-emitting diode chip on the temporary substrate.

[0089] In the manufacturing process of Micro LEDs or Mini LEDs, for example, transferring LED chips onto the driving circuitry of a backplane via a transfer substrate for bonding requires multiple bonding and debonding processes, increasing the probability of damage and defects in the LED chips. This invention also provides a mass transfer method for transferring LED chips fixed on a temporary storage substrate. Since the fixing force of the temporary storage substrate on the LED chips is provided by elastic deformation, the number of bonding and debonding operations during the transfer process can be reduced. Please refer to [link to relevant documentation]. Figure 17 and Figure 18 Mass transfer methods also include:

[0090] S21: Provide a transfer substrate and attach the transfer substrate to the light-emitting diode chip 6;

[0091] S31: A backplate 8 is provided, and the light-emitting diode chip 6 is transferred to the backplate 8 through the transfer substrate;

[0092] S41: The transfer substrate is peeled off from the light-emitting diode chip 6, and the light-emitting diode chip 6 is bonded to the backplate 8.

[0093] like Figure 17 and Figure 18 As shown, in step S11, for example, the shape of the electrode of the light-emitting diode chip matches the shape of the trench in the trench unit on the temporary storage substrate. During the process of the electrode and the trench, the trench and the elastic layer undergo elastic deformation, thereby generating a fixing force on the light-emitting diode chip. When the light-emitting diode chip on the temporary storage substrate is peeled off, the fixing force needs to be eliminated. This fixing force is generated by elastic deformation. In the process of eliminating the elastic force, the number of bonding and debonding is reduced, ensuring the uniformity of the quality of the light-emitting diode chip and improving the damage and dead pixels of the light-emitting diode chip caused by multiple bonding and debonding processes.

[0094] like Figure 18 As shown, in step S41, for example, the electrode 61 of the light-emitting diode chip 6 is bonded to the pad 81 on the driving circuit of the backplate 8 to realize the electrical signal connection between the driving circuit and the light-emitting diode chip 6, so that the driving circuit can control the light-emitting diode chip to turn on or off, increase or decrease the brightness, and multiple light-emitting diode chips can be used as display pixels of the display device to display color, brightness, contrast and saturation.

[0095] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A temporary storage substrate, characterized in that, include: First base; as well as An elastic layer is disposed on the first substrate, and the elastic layer includes a plurality of groove units; The trench unit has trenches for accommodating electrodes of a light-emitting diode chip, and at least a portion of the trenches have dimensions smaller than or equal to the dimensions of the electrodes. The grooves divide the elastic layer into multiple independent island-like structures, and the edges of the island-like structures are designed to be rounded or chamfered.

2. The temporary storage substrate according to claim 1, characterized in that, The light-emitting diode chip includes an electrode on the side near the elastic layer, and the trench unit includes a trench; the size of the trench is less than or equal to the size of the electrode.

3. The temporary storage substrate according to claim 1, characterized in that, The light-emitting diode chip includes at least two electrodes on the side near the elastic layer, and the at least two electrodes are housed in a trench unit, wherein the size of at least one trench is less than or equal to the size of the electrode.

4. The temporary storage substrate according to claim 1, characterized in that, The trench, whose size is less than or equal to the size of the electrode, has a length in a first direction that is less than or equal to the length of the electrode in the first direction; wherein the first direction includes a direction parallel to the plane containing the first substrate.

5. The temporary storage substrate according to claim 4, characterized in that, The trench, whose size is less than or equal to the size of the electrode, has a length in the second direction that is less than or equal to the length of the electrode in the second direction; wherein the second direction includes a direction parallel to the plane of the first substrate, and the second direction intersects the first direction.

6. The temporary storage substrate according to claim 1, characterized in that, The projection of the groove, whose size is less than or equal to that of the electrode, onto the plane of the first substrate lies within the projection of the corresponding electrode onto the plane of the first substrate.

7. The temporary storage substrate according to claim 3, characterized in that, The minimum trench spacing between adjacent trench units is greater than the distance between adjacent trenches within the same trench unit.

8. A method for manufacturing a temporary storage substrate, characterized in that, include: A second substrate is provided, and the second substrate is etched to form multiple protrusions; A first substrate is provided, and an elastic solution is coated on the first substrate; The first substrate is imprinted using the second substrate, and a plurality of trench units are formed on the first substrate, wherein the trenches in the trench units are used to accommodate the electrodes of a light-emitting diode chip, and at least a portion of the trenches have a size less than or equal to the size of the electrodes.

9. The method for manufacturing a temporary storage substrate according to claim 8, characterized in that, The step of providing a second substrate and etching the second substrate to form a plurality of protrusions includes: A photoresist layer is coated on the second substrate and photolithography is performed to form multiple photoresist units; The second substrate is etched using the photoresist unit as a mask to form multiple protrusions.

10. A mass transfer method, characterized in that, include: A temporary storage substrate is provided, the temporary storage substrate including a first substrate and an elastic layer, the elastic layer being disposed on the first substrate, and the elastic layer including a plurality of trench units, wherein the trenches in the trench units are used to accommodate electrodes of a light-emitting diode chip, and at least a portion of the trenches have a size less than or equal to the size of the electrodes; A growth substrate is provided, on which a plurality of light-emitting diode chips are disposed; The temporary storage substrate is placed above the growth substrate, and the temporary storage substrate is aligned with the growth substrate. Pressure is applied from one side of the temporary substrate and / or the growth substrate to cause the electrode to be engaged in at least a portion of the trench with a size smaller than or equal to that of the electrode under the action of the elastic layer; The growth substrate is peeled off.

11. The mass transfer method according to claim 10, characterized in that, Also includes: Each of the light-emitting diode chips on the temporary storage substrate is transferred and bonded to a backplane.

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