Transfer apparatus and transfer method for micro light emitting diodes

Abstract

The application discloses a transfer device and a transfer method for micro light emitting diodes. The transfer device comprises a carrier substrate and an expandable material. The carrier substrate is provided with a groove for accommodating the micro light emitting diodes. The expandable material is arranged at the bottom of the groove. The micro light emitting diodes are ejected by the expandable material, vacuum adsorption is avoided, and the micro light emitting diodes can be transferred more safely.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro light emitting diode manufacturing, in particular to a micro light emitting diode transfer device and a transfer method. BACKGROUND

[0002] In the prior art, the transfer device for transferring micro light emitting diodes is usually a vacuum suction device, but micro light emitting diodes are small and fragile, and vacuum suction can easily damage micro light emitting diodes.

[0003] In addition, in the prior art, the transfer method for transferring micro light emitting diode arrays with bridge arm structures is prone to break the bridge arm structure, so that the micro light emitting diodes fall into the grooves, and the micro light emitting diodes falling into the grooves cannot be transferred when using the vacuum suction device for transfer. SUMMARY

[0004] The present application aims to overcome the above-mentioned defects in the prior art, and provides a micro light emitting diode transfer device and a transfer method, which uses an expandable material to eject micro light emitting diodes, avoids using vacuum suction, and can more safely transfer micro light emitting diodes, and the method of the present application can transfer 100% of micro light emitting diode arrays with bridge arm structures.

[0005] To achieve the above-mentioned purpose, the technical solution of the present application is as follows:

[0006] A micro light emitting diode transfer device, characterized in that it comprises a carrier substrate and an expandable material, the carrier substrate is provided with a groove for accommodating a micro light emitting diode, and the expandable material is arranged at the bottom of the groove.

[0007] The present application also provides a micro light emitting diode transfer method, comprising the following processes:

[0008] A micro light emitting diode transfer device is provided, which comprises a carrier substrate and an expandable material, the carrier substrate is provided with a groove for accommodating a micro light emitting diode, and the expandable material is arranged at the bottom of the groove, so that the opening of the groove is upward;

[0009] A micro light emitting diode is placed in the groove, and the micro light emitting diode is located above the expandable material;

[0010] The expandable material is excited to expand, and the expansion of the expandable material ejects the micro light emitting diode out of the groove;

[0011] The micro light emitting diode is combined with a target substrate.

[0012] The implementation of the present application will have the following beneficial effects:

[0013] The embodiment of the present application sets the expandable material at the bottom of the groove for accommodating the micro light emitting diode, which can protect the micro light emitting diode and reduce environmental pollution. When the micro light emitting diode needs to be transferred to a target substrate, the expandable material is only needed to be expanded to push the micro light emitting diode out of the groove, so that the micro light emitting diode can be combined with the target substrate. The expandable material can push all the micro light emitting diodes out of the groove, and there is no case that part of the micro light emitting diodes is not pushed out, so the success rate of the transfer is higher. Therefore, the transfer device of the present application can not only ensure the safety of the micro light emitting diode, but also ensure that the success rate of the transfer reaches 100%. On the other hand, when the micro light emitting diodes to be transferred are connected by a bridge arm, the expandable material can push the micro light emitting diodes out together during the transfer, so there is no need to worry about the problem that the micro light emitting diode falls to the bottom of the groove and cannot be transferred due to the breakage of the bridge arm. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0015] In the drawings:

[0016] Figure 1 is a structural schematic diagram of a micro light emitting diode transfer device according to an embodiment of the present application.

[0017] Figure 2 is Figure 1 is a structural schematic diagram of the expandable material after expansion in the structure shown in

[0018] Figure 3 is a structural schematic diagram of a micro light emitting diode transfer device according to another embodiment of the present application.

[0019] Figure 4 is Figure 3 is a structural schematic diagram of the expandable material after expansion in the structure shown in

[0020] Figure 5 is a structural schematic diagram of a micro light emitting diode transfer device according to another embodiment of the present application.

[0021] Figure 6 is Figure 5 is a structural schematic diagram of the micro light emitting diode released by laser irradiation in the structure shown in

[0022] Figure 7 isFigure 6 Structure diagram of the structure shown after removing the substrate.

[0023] Figure 8 Figure 7 Structure diagram of the structure shown after the expandable material expands.

[0024] Figure 9 Figure 5 Structure diagram of the structure shown after the expandable material expands.

[0025] Figure 10 Structure diagram of the transfer device of the micro light emitting diode according to another embodiment of the present application.

[0026] Figure 11 Figure 10 Structure diagram of the structure shown after the expandable material expands. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0028] Embodiment 1

[0029] With reference to Figures 1-4 The present application discloses a transfer device of a micro light emitting diode 20, comprising a carrier substrate 11 and an expandable material 12, the carrier substrate 11 is provided with a groove 13 for accommodating the micro light emitting diode 20, and the expandable material 12 is arranged at the bottom of the groove 13. By arranging the expandable material 12 at the bottom of the groove 13, the groove 13 is used for accommodating the micro light emitting diode 20, the groove 13 can protect the micro light emitting diode 20 and reduce environmental pollution. When it is needed to transfer the micro light emitting diode 20 to a target substrate, the expandable material 12 is only needed to be excited to expand, the micro light emitting diode 20 is pushed out of the groove 13 by the expansion of the expandable material 12, so that the micro light emitting diode 20 can be combined with the target substrate. The expandable material 12 can uniformly push all the micro light emitting diodes 20 out of the groove 13, and there is no case that part of the micro light emitting diodes 20 is not pushed out, and the transfer success rate is higher. Therefore, the transfer device of the present application not only can guarantee the safety of the micro light emitting diode 20, but also can guarantee that the transfer success rate reaches 100%.

[0030] ​​​The number of micro light emitting diodes 20 is multiple, and the multiple micro light emitting diodes 20 can be transferred in batches. When the multiple micro light emitting diodes 20 are transferred in batches, the number of grooves 13 can be only one, and the multiple micro light emitting diodes 20 to be transferred fall into the same groove 13, or the number of grooves 13 can be more than two, and one groove 13 contains one or a group of micro light emitting diodes 20.

[0031] The expandable material 12 can be any expandable material in principle, such as a thermal type, an electric type, a light type, or a chemical sensing type expansion material, etc. In a preferred embodiment, the expandable material 12 is a memory polymer deformation material. The memory polymer deformation material is a product with an initial shape, which can be expanded and fixed under the excitation of certain conditions, and can restore its initial shape through the stimulation of external conditions (such as heat, electricity, light, chemical sensing, etc.). By using the memory polymer deformation material as the expandable material 12, on the one hand, the transfer device can be reused, and on the other hand, the shape of the expandable material 12 before and after expansion can be controlled.

[0032] The memory polymer deformation material can be thermal type, electric type, light type, or chemical sensing type, etc. The thermal type memory polymer deformation material can be expanded by heating or cooling to excite the expandable material 12; the electric type memory polymer deformation material mainly expands by exciting the expandable material 12 through conductive or non-conductive states; the light type memory polymer deformation material mainly expands by exciting the expandable material 12 through light (laser, ultraviolet light, etc.) irradiation; and the chemical sensing type memory polymer deformation material mainly expands by exciting the expandable material 12 through chemical reaction.

[0033] In a preferred embodiment, the transfer device further comprises a bonding layer 14 arranged above the expandable material 12, which is used to bond and fix the micro light emitting diode 20, and on the other hand, the bonding layer 14 also acts as an isolation layer to isolate the expandable material 12 from the micro light emitting diode 20, so as to avoid direct contact between the expandable material 12 and the micro light emitting diode 20, and to prevent the micro light emitting diode 20 from being contaminated.

[0034] In a preferred embodiment, the bonding layer can be PDMS (polydimethylsiloxane), which has elasticity and moderate adhesion. By using PDMS to adhere the micro light emitting diode 20, there will be no PDMS residue on the micro light emitting diode 20. Usually, the PDMS is bonded to the micro light emitting diode 20 by slight embossing. The deeper the depth of embossing, the stronger the bonding force. On the other hand, the adhesion of PDMS will decrease when it is heated. When the expandable material is a thermal expansion material, the heat excites the thermal expansion material to expand, and at the same time, the heat reduces the adhesion of the PDMS, so that the micro light emitting diode can be separated from the bonding layer, thereby better completing the transfer.

[0035] The material of the carrier substrate 11 can be a hard material such as glass or the like, or a flexible material such as a flexible resin material (polyimide, epoxy resin, or the like), a eutectic metal or a soft metal, or the like, which can be appropriately selected as needed. The carrier substrate 11 can be a material formed in one piece, or can be a structure formed by connecting two or more members, and a device for exciting the expandable material 12 to expand can be provided inside the carrier substrate 11, such as a heating device for exciting the expandable material 12 to expand by heat, or the like. Of course, the device for exciting such as the heating device can also be provided separately from the carrier substrate 11, such as by placing the carrier substrate 11 in a sealed heating chamber to heat, or placing the carrier substrate 11 on a stage with a heating function to heat, or the like.

[0036] In an embodiment, the transfer device further comprises an isolation layer, the isolation layer is arranged above the expandable material, and the isolation layer is configured to isolate the expandable material from the micro light emitting diodes.

[0037] Reference Figure 3 and Figure 4 In an embodiment, the transfer device further comprises a blocking member 15, the blocking member 15 is arranged at the opening of the groove 13, when the expandable material 12 expands, the expandable material 12 abuts against the blocking member 15, at this time, the abutting force makes the expandable material 12 and the transfer device in a relatively fixed state, moving the transfer device can make the micro light emitting diodes 20 remain fixed, avoiding displacement, resulting in inaccurate positioning with the target substrate. After the blocking member 15 abuts against the expandable material 12, the height of all the micro light emitting diodes 20 can be kept consistent, which is conducive to accurate positioning with the target substrate.

[0038] When the expandable material 12 is further provided with a bonding layer 14 above, when the expandable material 12 expands, the bonding layer 14 abuts against the blocking member 15. When the bonding layer 14 is provided, the bonding layer 14 bonds the micro light emitting diodes 20, at this time, the transfer device can be rotated to make the opening of the groove 13 downward.

[0039] In an embodiment, a transfer method of a micro light emitting diode 20 can comprise the following steps:

[0040] Step 11: providing a transfer device, the transfer device comprising: a carrier substrate 11 and an expandable material 12, the carrier substrate 11 is provided with a groove 13 for accommodating a micro light emitting diode 20, and the expandable material 12 is arranged at the bottom of the groove 13, so that the opening of the groove 13 is upward.

[0041] Step 12: placing the micro light emitting diode 20 in the groove 13, the micro light emitting diode 20 is above the expandable material 12.

[0042] Step 13: expand the expandable material 12 to eject the micro light emitting diode 20 out of the groove 13.

[0043] Step 14: combine the micro light emitting diode 20 with a target substrate.

[0044] In this embodiment, when transferring, the micro light emitting diode 20 is first put into the groove 13, and when transferring the micro light emitting diode 20 to a target substrate, the expandable material 12 is expanded to eject the micro light emitting diode 20 out of the groove 13.

[0045] The target substrate can be any temporary transfer substrate used in the manufacturing process, or a driving circuit board.

[0046] In another embodiment, a method for transferring a micro light emitting diode 20 can include the following steps:

[0047] Step 21: provide a transfer device, which includes a carrier substrate 11 and an expandable material 12, the carrier substrate 11 is provided with a groove 13 for accommodating a micro light emitting diode 20, the expandable material 12 is arranged at the bottom of the groove 13, the expandable material 12 is a thermally induced memory polymer deformation material, and the transfer device further includes an adhesive layer 14 arranged above the expandable material 12, so that the opening of the groove 13 is upward.

[0048] Step 22: heat to expand the expandable material 12, and at the same time, heat to weaken the adhesion of the adhesive layer 14.

[0049] Step 23: release the micro light emitting diode 20 onto the molten adhesive layer 14.

[0050] Step 24: cool the expandable material 12, the expandable material 12 returns to its original state, and at the same time, the adhesion of the adhesive layer 14 is enhanced to fix the micro light emitting diode 20.

[0051] Step 25: heat again to expand the expandable material 12 to eject the micro light emitting diode 20 out of the groove 13, and at the same time, heat to weaken the adhesion of the adhesive layer 14 to combine the micro light emitting diode 20 with a target substrate.

[0052] In this embodiment, the thermally induced memory polymer deformation material is matched with the adhesive layer 14 which is heated, melted, cooled and solidified, which not only facilitates the accurate positioning of the micro light emitting diode 20, but also facilitates the release of the micro light emitting diode 20.

[0053] In another embodiment, a method for transferring a micro light emitting diode 20 can include the following steps:

[0054] Step 31: providing a transfer device, the transfer device comprising a carrier substrate 11 and an expandable material 12, the carrier substrate 11 being provided with a recess 13 for accommodating a micro light emitting diode 20, the expandable material 12 being arranged at the bottom of the recess 13, the expandable material 12 being a memory polymer deformation material, the transfer device further comprising a bonding layer 14 arranged above the expandable material 12, the bonding layer 14 being made of PDMS, and the opening of the recess 13 being upward.

[0055] Step 32: exciting the expandable material 12 to expand, and pressing the micro light emitting diode 20 onto the bonding layer 14 of the PDMS.

[0056] Step 33: restoring the expandable material 12 to its original state, and accommodating the micro light emitting diode 20 together with the bonding layer 14 into the recess 13.

[0057] Step 34: arranging the target substrate opposite to the transfer device, and exciting the expandable material 12 to expand, and connecting the micro light emitting diode 20 to the target substrate when the expandable material 12 expands.

[0058] In the specific embodiment, by using the elastic imprinting material as the bonding layer 14, the adhesive residue is avoided, and by using the pushing force of the expandable material 12 when it expands, the micro light emitting diode 20 is facilitated to be connected to the target substrate.

[0059] Preferably, in the specific embodiment, when the target substrate is a temporary transfer substrate, the temporary transfer substrate is preferably an elastic imprinting substrate, and when the target substrate is a driving circuit board, a welding electrode can be directly arranged on the top of the micro light emitting diode 20, and the pushing force of the expandable material 12 can directly realize the electrical connection of the micro light emitting diode 20 to the driving circuit board.

[0060] Embodiment 2

[0061] Reference Figures 5-9 Compared with Embodiment 1, the improvement of Embodiment 2 is that the transfer device further comprises a positioning structure arranged on the carrier substrate 11, the positioning structure being used for positioning the micro light emitting diode 20, so that the micro light emitting diode 20 is opposite to the transfer device, and especially when the micro light emitting diode 20 is multiple, the positioning structure can position all the micro light emitting diodes 20 at one time. By arranging the positioning structure, the positioning of the batch of micro light emitting diodes 20 is facilitated, and the difficulty of positioning the transfer device and the batch of micro light emitting diodes 20 is reduced.

[0062] Reference Figure 5 and Figure 7In a specific embodiment, the positioning structure is the clamping structure 16, the array substrate includes a substrate 25 and a plurality of micro light emitting diodes 20 arrayed on the substrate 25, the clamping structure 16 is used to clamp and connect with the substrate 25, and the array substrate is connected with the carrier substrate 11 through the clamping structure 16. At this time, the micro light emitting diodes 20 are suspended in the grooves 13, and the clamping structure 16 can keep the transfer device and the array substrate fixed, facilitating positioning of all micro light emitting diodes 20. After the array substrate is clamped and connected with the transfer device, the micro light emitting diodes 20 are caused to fall into the grooves 13, so that the distance between the micro light emitting diodes 20 and the transfer device during positioning can be minimized. The smaller the distance, the smaller the displacement caused during the transfer process, and the more accurate the positioning.

[0063] Specifically, in the specific embodiment, the clamping structure 16 is a clamping groove.

[0064] In the specific embodiment, the substrate 25 can be a substrate for growing an epitaxial wafer, or a temporary transfer substrate. When the substrate 25 is a substrate, the substrate can be removed by mechanical polishing to release the micro light emitting diodes 20, or the micro light emitting diodes 20 can be released by laser irradiation. When the substrate 25 is a temporary transfer substrate, the micro light emitting diodes 20 can be released by laser or ultraviolet light irradiation, heating, or solution dissolution.

[0065] In a specific embodiment, referring to Figures 5-8 A transfer method of a micro light emitting diode 20 can include the following steps.

[0066] Step 41: providing a transfer device, the transfer device including a carrier substrate 11 and an expandable material 12, the carrier substrate 11 being provided with grooves 13 for accommodating micro light emitting diodes 20, the expandable material 12 being arranged at the bottom of the grooves 13, and the transfer device further including a clamping structure 16 arranged on the carrier substrate 11 to make the opening of the grooves 13 upward; and providing an array substrate, the array substrate including a substrate 25 and a plurality of micro light emitting diodes 20 arrayed on the substrate 25.

[0067] In this step, the substrate 25 can be a substrate for growing an epitaxial wafer, such as sapphire, or a temporary transfer substrate.

[0068] Step 42: connecting the substrate 25 with the clamping structure 16 to make the array substrate opposite to the transfer device, at this time, the micro light emitting diodes 20 are suspended in the grooves 13.

[0069] Step 43: releasing the micro light emitting diodes 20, and causing the micro light emitting diodes 20 to fall into the grooves 13.

[0070] In this step, the micro light emitting diode 20 can be released by mechanical peeling or laser irradiation.

[0071] Preferably, a bonding layer 14 is further arranged above the expandable material 12, and the micro light emitting diode 20 falls onto the bonding layer 14 and is fixedly connected with the bonding layer 14.

[0072] Step 44: expand the expandable material 12 to push the micro light emitting diode 20 out of the groove 13 and combine the micro light emitting diode 20 with the target substrate.

[0073] In another specific embodiment, referring to Figure 5 and Figure 9 a transfer method of a micro light emitting diode 20 can include the following steps:

[0074] Step 51: provide a transfer device, which includes a carrier substrate 11 and an expandable material 12, the carrier substrate 11 is provided with a groove 13 for accommodating the micro light emitting diode 20, the expandable material 12 is arranged at the bottom of the groove 13, and the transfer device further includes a clamping structure 16 arranged on the carrier substrate 11 to make the opening of the groove 13 upward;

[0075] An array substrate is provided, which includes a substrate 25 and a plurality of micro light emitting diodes 20 arranged in an array on the substrate 25.

[0076] Step 52: connect the substrate 25 with the clamping structure 16 to make the array substrate opposite to the transfer device, at this time, the micro light emitting diode 20 is suspended in the groove 13.

[0077] Step 53: expand the expandable material 12 to push the micro light emitting diode 20 out of the groove 13 together with the substrate 25.

[0078] In this embodiment, preferably, a bonding layer 14 is arranged above the expandable material 12, and the bonding layer 14 is fixedly connected with the micro light emitting diode 20 when the expandable material 12 expands to push the micro light emitting diode 20, and preferably, the bonding layer 14 is an elastic imprint material.

[0079] Step 54: remove the substrate 25.

[0080] In this step, the substrate 25 can be removed by mechanical peeling, laser irradiation or heating, etc. For example, the material of the substrate 25 is a photosensitive material, which can be removed by laser irradiation, the material of the substrate 25 is a heat-sensitive material, etc., which can be removed by heating, the material of the substrate 25 is a sapphire substrate for growing an epitaxial wafer, etc., which can be removed by mechanical peeling or laser irradiation, etc.

[0081] Step 55: combine the micro light emitting diode 20 with a target substrate.

[0082] Reference Figures 10-11 In another embodiment, the positioning structure is a bonding structure, the bonding structure is used to bond and fix with the bridge arm 21, the adjacent micro light emitting diodes 20 are connected through the bridge arm 21, and the micro light emitting diode 20 is suspended in the groove 13. When the expandable material 12 expands, the micro light emitting diode 20 is pushed out of the groove 13 by the expansion of the expandable material 12, and the micro light emitting diode 20 is separated from the bridge arm 21.

[0083] Further, the positioning structure includes the clamping structure 16 and the bonding structure, the clamping structure 16 is used to clamp and connect with the bridge arm 21, and the bonding structure is arranged between the carrier substrate 11 and the bridge arm 21, and is used to bond and fix with the bridge arm 21. It should be noted that the bonding structure includes bonding by an adhesive, and also includes bonding by imprint bonding.

[0084] In an embodiment, reference Figure 10 and Figure 11 A transfer method of a micro light emitting diode 20 can include the following steps:

[0085] Step 61: provide a transfer device, the transfer device includes a carrier substrate 11 and an expandable material 12, the carrier substrate 11 is provided with a groove 13 for accommodating a micro light emitting diode 20, the expandable material 12 is arranged at the bottom of the groove 13, and the transfer device further includes a bonding structure arranged on the carrier substrate 11, so that the opening of the groove 13 is upward.

[0086] An array substrate is provided, the array substrate includes a bridge arm 21 and a plurality of micro light emitting diodes 20 arranged in an array, and the adjacent micro light emitting diodes 20 are connected through the bridge arm 21.

[0087] Step 62: connect the bridge arm 21 with the bonding structure, so that the array substrate is opposite to the transfer device, and the micro light emitting diode 20 is suspended in the groove 13.

[0088] Step 63: stimulate the expansion of the expandable material 12, the micro light emitting diode 20 is pushed out of the groove 13 by the expansion of the expandable material 12, and the micro light emitting diode 20 is separated from the bridge arm 21.

[0089] Step 64: combine the micro light emitting diode 20 with a target substrate.

[0090] Embodiment 3

[0091] Compared with Embodiment 1 and Embodiment 2, the improvement of Embodiment 3 is the further improvement of the material of the carrier substrate 11.

[0092] In an embodiment, the reference carrier substrate 11 comprises a bottom plate 111 and a top plate 112 connected to the bottom plate 111, the top plate 112 is provided with the recess 13, and the material of the top plate 112 is a flexible material such as a flexible resin material (polyimide, epoxy resin, etc.), a eutectic metal or a soft metal, etc., and the recess 13 can be formed by polishing, stamping or etching the top plate 112. The top plate 112 is made of the flexible material, and the purpose is to make the top plate 112 easy to be bonded to the temporary transfer substrate or the substrate by pressure, so that the top plate 112 is fixedly connected to the temporary transfer substrate or the substrate, and the step of coating the adhesive can be omitted, and the process is simpler.

[0093] In an embodiment, the material of the bottom plate 111 is a transparent material such as transparent glass, etc., and the expandable material 12 can be excited by transmitting heat energy or light energy by light irradiation such as laser. The carrier substrate 11 is more suitable for use in multiple steps of the preparation process of the micro light emitting diode 20.

[0094] In summary, the transfer device of the present application is safer than the vacuum suction device of the prior art, and the process of ejecting the micro light emitting diode 20 by the expandable material 12 is 100% ejection, so that the success rate of transfer can reach 100%.

[0095] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A transfer apparatus for micro light emitting diodes, characterized by The micro light emitting diode transfer device comprises: a carrier substrate and an expandable material, the carrier substrate is provided with a groove for accommodating a micro light emitting diode, and the expandable material is arranged at the bottom of the groove; Further comprising a positioning structure arranged on the carrier substrate, the positioning structure is used for positioning the micro light emitting diode; The positioning structure is a clamping structure and / or a bonding structure; In the case that the positioning structure is the clamping structure, the array substrate comprises a substrate and a plurality of micro light emitting diodes arrayed on the substrate, the clamping structure is used for clamping connection with the substrate, the array substrate is connected with the carrier substrate through the clamping structure, so as to keep the array substrate and the carrier substrate fixed, and the micro light emitting diode is suspended in the groove, and after the array substrate and the carrier substrate are clamped and connected, the micro light emitting diode can fall into the groove; In the case that the positioning structure is the bonding structure, the adjacent micro light emitting diodes are connected through a bridge arm, the bonding structure is used for bonding and fixing with the bridge arm, so as to suspend the micro light emitting diode in the groove, and when the expandable material expands, the expandable material expands to push the micro light emitting diode out of the groove, so that the micro light emitting diode is separated from the bridge arm.

2. The micro light emitting diode transfer apparatus of claim 1, wherein, The expandable material is a memory polymer deformation material.

3. The micro LED transfer apparatus of claim 2, wherein, The memory polymer deformation material is a thermal type memory polymer deformation material, an electrical type memory polymer deformation material, a light type memory polymer deformation material or a chemical sensing type memory polymer deformation material.

4. The micro LED transfer apparatus of claim 3, wherein, Further comprising a bonding layer arranged above the expandable material, the bonding layer is used for fixing the micro light emitting diode.

5. The micro LED transfer apparatus of claim 4, wherein, The bonding layer material is PMDS.

6. The micro LED transfer apparatus according to any one of claims 1 to 5, wherein Further comprising a blocking member arranged at the opening of the groove, when the expandable material expands, the expandable material abuts against the blocking member.

7. The micro LED transfer apparatus according to any one of claims 1-5, wherein The carrier substrate comprises a bottom plate and a top plate arranged on the bottom plate, the top plate is provided with the groove, and the material of the top plate is a flexible resin material, a eutectic metal or a soft metal; The material of the bottom plate is a transparent material; Further comprising an isolation layer arranged above the expandable material, the isolation layer is used for isolating the expandable material from the micro light emitting diode.

8. A method of transferring micro light emitting diodes, characterized by, The micro light emitting diode transfer device comprises the following processes: Providing the micro light emitting diode transfer device as claimed in claim 1, and making the opening of the groove upward; Placing a micro light emitting diode in the groove, the micro light emitting diode is above the expandable material; Expanding the expandable material, the expandable material expands to push the micro light emitting diode out of the groove; Combining the micro light emitting diode with a target substrate.

Images