Micro light-emitting chip transfer device, manufacturing method and transfer method

Abstract

The invention relates to a micro light-emitting chip transfer device, a manufacturing method and a transfer method. The micro light-emitting chip transfer device comprises a substrate; the bonding layer is fixedly arranged on the substrate, and a plurality of salient points are arranged on one surface, far away from the substrate, of the bonding layer; the bonding layer is configured in a way that one surface, far away from the substrate, of the bonding layer is attached to the surface of the micro light-emitting chip when the micro light-emitting chip is transferred; at the same time, at least a part of the salient points of the bonding layer are attached to the concave parts on the surface of the micro light-emitting chip in an aligned manner. The bonding layer is provided with a plurality of convex points, and the bonding layer can be bonded with the surface of the micro light-emitting chip in an attached mode in the transferring process and can also be bonded with the concave parts in the surface of the micro light-emitting chip in an attached mode through the convex points, so that the bonding area between the bonding layer and the micro light-emitting chip is increased, bonding is firmer, and the pickup yield of the chip is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a micro-light-emitting chip transfer device, a manufacturing method, and a transfer method. Background Art

[0002] Micro-LED (Micro Light Emitting Diode), which has the advantages of high brightness, wide color gamut coverage and high contrast, has been sought after by various manufacturers and is called the next-generation display technology.

[0003] At present, in the manufacturing process of Micro-LED, the micro-light-emitting chip needs to be transferred to a temporary substrate, and then the micro-light-emitting chip on the temporary substrate is picked up and transferred to the backplane by a stamp. In order to improve the luminous efficiency of the micro-light-emitting chip, a luminous epitaxial structure will be grown on the patterned substrate. The surface of the micro-light-emitting chip thus made will have several concave parts. In the process of picking up the micro-light-emitting chip with the stamp, the adhesive surface of the stamp cannot be completely in contact with the surface of the micro-light-emitting chip with the concave parts, resulting in the problem of weak adhesion between the stamp and the micro-light-emitting chip, which reduces the chip picking yield.

[0004] Therefore, how to improve the chip picking yield is an urgent problem to be solved. Summary of the invention

[0005] In view of the deficiencies of the above-mentioned related technologies, the purpose of the present application is to provide a micro-light-emitting chip transfer device and a manufacturing method and a transfer method, aiming to solve the problem of low chip pickup yield.

[0006] A micro light-emitting chip transfer device, comprising:

[0007] substrate; and

[0008] An adhesive layer is fixedly arranged on the substrate, and a plurality of protrusions are arranged on a side of the adhesive layer away from the substrate; the adhesive layer is configured so that when the micro-light-emitting chip is transferred, the side of the adhesive layer away from the substrate is bonded to the surface of the micro-light-emitting chip; and at the same time, at least a part of the protrusions of the adhesive layer are aligned and bonded to the concave parts on the surface of the micro-light-emitting chip.

[0009] In the above-mentioned chip transfer device, the adhesive layer has a plurality of protrusions. During the transfer process, the adhesive layer can not only adhere to the surface of the micro light-emitting chip, but also adhere to the recessed parts on the surface of the micro light-emitting chip through the protrusions, thereby increasing the bonding area between the adhesive layer and the micro light-emitting chip, making the bonding stronger and improving the chip pickup yield.

[0010] Optionally, the adhesive layer includes a support adhesive layer and an adhesive layer. The support adhesive layer is disposed between the substrate and the adhesive layer, and the hardness of the support adhesive layer is greater than that of the adhesive layer. Since the support adhesive layer has a relatively large hardness and undergoes little deformation during the transfer process, the position accuracy of the transfer of the micro-light-emitting chip can be improved, ensuring a high transfer yield. On the other hand, the adhesive layer has a relatively small hardness and good deformation ability, which is more conducive to the good adhesion between the adhesive layer and the micro-light-emitting chip during the transfer process, improving the pick-up yield of the chip.

[0011] Based on the same inventive concept, the present application also provides a method for manufacturing the above-mentioned micro-light-emitting chip transfer device, including:

[0012] Disposing the adhesive layer on the substrate, and a plurality of the bumps are disposed on a surface of the adhesive layer away from the substrate.

[0013] In the method for manufacturing the above chip transfer device, the manufactured adhesive layer has a plurality of bumps, so that during the transfer process, the adhesive layer can not only be adhered to the surface of the micro-light-emitting chip, but also be adhered to the concave portions on the surface of the micro-light-emitting chip through the bumps, thereby increasing the bonding area between the adhesive layer and the micro-light-emitting chip, making the bonding more firm and improving the pick-up yield of the chip.

[0014] Based on the same inventive concept, the present application also provides a method for transferring a micro-light-emitting chip, including:

[0015] Providing the above-mentioned micro-light-emitting chip transfer device;

[0016] Bringing a surface of the adhesive layer away from the substrate into contact with the surface of the micro-light-emitting chip, and aligning and fitting at least a part of the bumps of the adhesive layer with the concave portions on the surface of the micro-light-emitting chip;

[0017] Removing the carrier substrate of the micro-light-emitting chip.

[0018] In the above method for transferring a micro-light-emitting chip, the adhesive layer of the micro-light-emitting chip transfer device has a plurality of bumps, so that during the transfer process, the adhesive layer can not only be adhered to the surface of the micro-light-emitting chip, but also be adhered to the concave portions on the surface of the micro-light-emitting chip through the bumps, thereby increasing the bonding area between the adhesive layer and the micro-light-emitting chip, making the bonding more firm and improving the pick-up yield and transfer yield of the chip. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of a micro-light-emitting chip transfer device provided by an embodiment of the present application;

[0020] Figure 2 is a schematic structural diagram of bumps disposed on the adhesive layer provided by an embodiment of the present application;

[0021] Figure 3 Another structural schematic diagram of the micro light-emitting chip transfer device provided by the embodiment of the present application;

[0022] Figure 4 Still another structural schematic diagram of the micro light-emitting chip transfer device provided by the embodiment of the present application;

[0023] Figure 5 Yet another structural schematic diagram of the micro light-emitting chip transfer device provided by the embodiment of the present application;

[0024] Figure 6 Structural schematic diagram of a micro light-emitting chip to be transferred on a carrier substrate provided by the embodiment of the present application, where the surface of the micro light-emitting chip has several recesses;

[0025] Figure 7 Schematic diagram of the micro light-emitting chip transfer device provided by the embodiment of the present application transferring a micro light-emitting chip;

[0026] Figure 8 Flowchart of a method for manufacturing a micro light-emitting chip transfer device provided by another alternative embodiment of the present application;

[0027] Figure 9 Flowchart of a micro light-emitting chip transfer method provided by still another alternative embodiment of the present application;

[0028] Explanation of reference numerals:

[0029] 1 - Substrate; 2 - Adhesive layer; 201 - Bump; 202 - Support glue layer; 203 - Adhesive layer; 3 - Micro light-emitting chip; 301 - Recess. Detailed implementation manners

[0030] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs. The terms used in the specification of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0032] Currently, in the manufacturing process of Micro-LEDs, it is necessary to transfer micro-light-emitting chips to a transient substrate, and then pick up and transfer the micro-light-emitting chips on the transient substrate to the backplane through a stamp. In order to improve the light-emitting efficiency of the micro-light-emitting chips, a light-emitting epitaxial structure is grown on the patterned substrate. The surface of the patterned substrate has several convex structures, and the surface of the epitaxial structure grown on the patterned substrate that contacts the substrate will have several concave portions, as Figure 6 shown. Therefore, the surface of the micro-light-emitting chip finally fabricated after peeling off the patterned substrate will have several concave portions. During the process of the stamp picking up the micro-light-emitting chip, the bonding surface of the stamp cannot be completely attached to the surface of the micro-light-emitting chip with concave portions, resulting in the problem of poor bonding between the stamp and the micro-light-emitting chip, which reduces the picking yield of the chip.

[0033] Based on this, the present application hopes to provide a solution that can solve the above technical problems, and its detailed content will be elaborated in the following embodiments.

[0034] This embodiment provides a micro-light-emitting chip transfer device, which can be applied to the mass transfer of micro-light-emitting chips. It can be understood that the micro-light-emitting chips in this embodiment may include, but are not limited to, Mini LED (Mini Light Emitting Diode, sub-millimeter light-emitting diode), Micro LED (Micro Light Emitting Diode, micron-scale light-emitting diode), nano-scale light-emitting diodes, and the like.

[0035] As Figures 1-7 shown, the micro-light-emitting chip transfer device in this embodiment includes a substrate 1 and an adhesive layer 2. It can be understood that the substrate 1 in this embodiment serves to carry and support the adhesive layer 202 and the adhesive layer 2, and can be made of a material with a certain hardness, such as, but not limited to, glass or sapphire. Specifically, the glass can be ordinary glass or quartz glass. The thickness of the substrate 1 in this embodiment is not specifically limited and can be set as needed.

[0036] The adhesive layer 2 in this embodiment is fixed on the substrate 1, and a plurality of bumps 201 are provided on the surface of the adhesive layer 2 away from the substrate 1; the adhesive layer 2 is configured such that when transferring the micro-light-emitting chip 3, the surface of the adhesive layer 2 away from the substrate 1 is attached to the surface of the micro-light-emitting chip 3, and at least a part of the bumps 201 of the adhesive layer 2 is aligned and attached to the concave portions 301 on the surface of the micro-light-emitting chip 3. During the transfer process, the adhesive layer 2 can not only be attached and bonded to the surface of the micro-light-emitting chip 3, but also be attached and bonded to the concave portions 301 on the surface of the micro-light-emitting chip 3 through the bumps 201. Thus, the bonding area between the adhesive layer 2 and the micro-light-emitting chip 3 is increased, making the bonding more firm and improving the picking yield of the chip.

[0037] It can be understood that, as Figure 7 shown, when transferring, the side of the adhesive layer 2 away from the substrate 1 is attached to the surface of the micro light-emitting chip 3, that is, the surface area between the bumps 201 on the side of the adhesive layer 2 away from the substrate 1 is attached to the surface area between the recesses 301 on the micro light-emitting chip 3. In some application scenarios, it can be that a partial surface area between the bumps 201 on the side of the adhesive layer 2 away from the substrate 1 is attached to the surface area between the recesses 301 on the micro light-emitting chip 3 when transferring. In some application scenarios, it can also be that the entire surface area between the bumps 201 on the side of the adhesive layer 2 away from the substrate 1 is attached to the surface area between the recesses 301 on the micro light-emitting chip 3 when transferring.

[0038] In this embodiment, at least a part of the bumps 201 of the adhesive layer 2 are aligned and attached to the recesses 301 on the surface of the micro light-emitting chip 3 when transferring, that is, the surface of the bump 201 is in contact with the surface of the corresponding recess 301 to achieve bonding. In some embodiments, as Figure 4 shown, the bumps 201 can be arranged in a full-surface array on the side of the adhesive layer 2 away from the substrate 1. When transferring, select the corresponding part of the bumps 201 and the surface area between the corresponding part of the bumps 201 for bonding. In some embodiments, as Figure 1 、 Figure 3 shown, a plurality of independent array units can be arranged on the side of the adhesive layer 2 away from the substrate 1. One array unit corresponds to one micro light-emitting chip 3, and each array unit includes a plurality of bumps 201 arranged in an array. When transferring, all the bumps 201 on the adhesive layer 2 are used for bonding, and the surface area between the corresponding bumps 201 for the micro light-emitting chip 3 is used for bonding. In some application scenarios, as Figure 5 shown, several raised bonding units can be arranged on the side of the adhesive layer 2 away from the substrate 1. One bonding unit corresponds to one micro light-emitting chip 3, and several bumps 201 are arranged on the side of each bonding unit away from the substrate 1. When transferring, all the bumps 201 on the adhesive layer 2 are used for bonding, and the entire surface area between the bumps 201 is used for bonding.

[0039] In some embodiments, Figure 3 、 Figure 4, the adhesive layer 2 includes a support glue layer 202 and an adhesive layer 203. The support glue layer 202 is disposed between the substrate 1 and the adhesive layer 203, and the bump 201 is located on the side of the adhesive layer 203 away from the substrate 1. The hardness of the support glue layer 202 is greater than that of the adhesive layer 203. The support glue layer 202 has a relatively large hardness, and during the transfer process, the deformation of the support glue layer 202 is small, which can improve the position accuracy of the transfer of the micro-light-emitting chip 3 and ensure the transfer yield. While the adhesive layer 203 has a relatively small hardness and good deformation ability, which is more conducive to the good adhesion between the adhesive layer 203 and the micro-light-emitting chip 3 during the transfer process and improves the chip picking yield. In some application scenarios, the material of the support glue layer 202 may include any one of UV glue and PDMS glue, and the material of the adhesive layer 203 includes silicone gel. For example, the support glue layer 202 can be made of UV glue or PDMS glue, and the adhesive layer 203 is made of silicone gel. After production, the hardness of UV glue and PDMS glue is greater than that of silicone gel. The UV (Ultraviolet Rays) glue in this embodiment is ultraviolet glue, which is an adhesive cured by ultraviolet light, and the PDMS (Polydimethylsiloxane) glue is polydimethylsiloxane glue.

[0040] In this embodiment, the thicknesses of the support glue layer 202 and the adhesive layer 203 can be set as needed. In some application scenarios, in order to enable the support glue layer 202 to form a good support for the adhesive layer 203, as Figure 4 shown, the thickness D1 of the support glue layer 202 can be greater than the thickness D2 of the adhesive layer 203. For example, the thickness of the support glue layer 202 can be 20μm - 50μm, and the thickness of the adhesive layer 203 can be 1μm - 2μm.

[0041] In some embodiments, as Figure 1 , Figure 5 shown, the adhesive layer 2 can be an integral structure. The integral structure can also achieve the picking of the micro-light-emitting chip 3 by the adhesive layer 2. Still, the contact adhesion between the bump 201 and the concave portion 301 on the micro-light-emitting chip 3 can be used to increase the adhesion area between the adhesive layer 2 and the micro-light-emitting chip 3 and improve the chip picking yield. In some application scenarios, the material of the adhesive layer 2 includes any one of UV glue, PDMS glue, and silicone gel. For example, the adhesive layer 2 can be made of UV glue, PDMS glue, or silicone gel. A plurality of bumps 201 are provided on the side of the UV glue, PDMS glue, or silicone gel away from the substrate 1. Through the contact adhesion between the bumps 201 and the concave portion 301 on the micro-light-emitting chip 3, the adhesion area between the adhesive layer 2 and the micro-light-emitting chip 3 can be increased. When the adhesive layer 2 is made of silicone gel, in order to ensure the position accuracy of the transfer, the thickness of the silicone gel needs to be controlled within a relatively thin value range.

[0042] In some embodiments, the shape of the bump 201 can be adapted to the shape of the recess 301. For example, when the shape of the recess 301 is conical, the shape of the bump 201 is also conical; when the shape of the recess 301 is hemispherical, the shape of the bump 201 is also hemispherical; or when the shape of the recess 301 is frustum-shaped, the shape of the bump 201 is also frustum-shaped. In some application scenarios, for example, when the adhesive layer 2 is made of a material with a relatively low hardness and the deformation ability of the bump 201 is good, the shape of the bump 201 does not have to be adapted to the shape of the recess 301, and the adhesion between the surface of the bump 201 and the surface of the recess 301 can be ensured through the deformation of the adhesive layer 2 and the bump 201. In some embodiments, the size of the bump 201 does not have to match the size of the recess 301 either. For example, the size of the bump 201 can be made smaller than the size of the recess 301, and the adhesion between the surface of the bump 201 and the surface of the recess 301 can be achieved through the deformation ability of the adhesive layer 2 and the bump 201.

[0043] In the above micro light-emitting chip transfer device, the adhesive layer 2 has a number of bumps 201. During the transfer process, the adhesive layer 2 can not only be adhered to the surface of the micro light-emitting chip 3, but also be adhered to the recesses 301 on the surface of the micro light-emitting chip 3 through the bumps 201. As a result, the adhesion area between the adhesive layer 2 and the micro light-emitting chip 3 is increased, making the adhesion more firm and improving the pick-up yield of the chip.

[0044] Another optional embodiment of the present application:

[0045] This embodiment provides a manufacturing method of the above-mentioned micro light-emitting chip transfer device, including the following steps:

[0046] An adhesive layer 2 is provided on the substrate 1, and a number of bumps 201 are provided on the side of the adhesive layer 2 away from the substrate 1. In this embodiment, the specific setting of the adhesive layer 2 is the same as that in the above embodiment and will not be described in detail here.

[0047] In some embodiments, the adhesive layer 2 includes a support glue layer 202 and an adhesive layer 203. As Figure 8 shown, providing the adhesive layer 2 on the substrate 1 includes the following steps:

[0048] S11: Coat a layer of support glue on the substrate.

[0049] The support glue layer 202 in this embodiment is any one of UV glue and PDMS glue.

[0050] S12: After the support glue layer is cured, coat a layer of adhesive layer on the support glue layer.

[0051] The adhesive layer 203 in this embodiment is made of silicone gel.

[0052] S13: Imprint the side of the adhesive layer away from the substrate. After the adhesive layer cures, a number of bumps are formed on the side of the bonding layer away from the substrate.

[0053] In this embodiment, a number of bumps 201 can be formed at one time through nanoimprint technology.

[0054] The cured support adhesive layer 202 has a relatively high hardness and undergoes little deformation during the transfer process, which can improve the position accuracy of the transfer of the micro-light-emitting chip 3 and ensure the transfer yield. The cured adhesive layer 203 has a relatively low hardness and good deformation ability, which is more conducive to the good bonding between the adhesive layer 203 and the micro-light-emitting chip 3 during the transfer process and improves the chip pick-up yield.

[0055] In the manufacturing method of the above chip transfer device, the bonding layer 2 manufactured has a number of bumps 201, so that during the transfer process, the bonding layer 2 can not only be bonded to the surface of the micro-light-emitting chip 3, but also be bonded to the concave portion 301 on the surface of the micro-light-emitting chip 3 through the bumps 201. Thus, the bonding area between the bonding layer 2 and the micro-light-emitting chip 3 is increased, making the bonding more firm and improving the chip pick-up yield.

[0056] Another alternative embodiment of the present application:

[0057] This embodiment provides a method for transferring a micro-light-emitting chip, as Figure 9 shown, including the following steps:

[0058] S21: Provide a micro-light-emitting chip transfer device.

[0059] The micro-light-emitting chip transfer device in this embodiment is the same as the above embodiment and will not be elaborated here.

[0060] S22: Fit the side of the bonding layer away from the substrate to the surface of the micro-light-emitting chip, and align and fit at least a part of the bumps of the bonding layer with the concave portions on the surface of the micro-light-emitting chip.

[0061] Contact bonding can be formed between the bonding layer 2 and the surface of the micro-light-emitting chip 3 as well as the concave portion 301, realizing the complete fitting contact between the bonding layer 2 and the micro-light-emitting chip 3.

[0062] S23: Remove the carrier substrate of the micro-light-emitting chip.

[0063] The carrier substrate in this embodiment is the substrate that carried the micro-light-emitting chip 3 before transfer. After removing the carrier substrate of the micro-light-emitting chip 3, the micro-light-emitting chip 3 can be transferred to the backplane for bonding through the micro-light-emitting chip transfer device.

[0064] In the above micro light-emitting chip transfer method, the adhesive layer 2 of the micro light-emitting chip transfer device has a number of bumps 201, so that during the transfer process, the adhesive layer 2 can not only be bonded to the surface of the micro light-emitting chip 3, but also be bonded to the concave part 301 on the surface of the micro light-emitting chip 3 through the bumps 201. Thereby, the bonding area between the adhesive layer 2 and the micro light-emitting chip 3 is increased, making the bonding more firm, and improving the pick-up yield and transfer yield of the chip.

[0065] It should be understood that the application of this application 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 description, and all such improvements and transformations should fall within the protection scope of the appended claims of this application.

Claims

1. A micro light-emitting chip transfer device, characterized in that, Comprising: A substrate; And An adhesive layer fixedly provided on the substrate, and a plurality of bumps are provided on a surface of the adhesive layer away from the substrate; The adhesive layer is configured such that when transferring the micro light-emitting chip, the surface of the adhesive layer away from the substrate is attached to the surface of the micro light-emitting chip, and at least a part of the bumps of the adhesive layer are attached to the concave portions on the surface of the micro light-emitting chip in a position-aligned manner.

2. The micro light-emitting chip transfer device according to claim 1, wherein The adhesive layer includes a support adhesive layer and an adhesive layer, the support adhesive layer is provided between the substrate and the adhesive layer, and the hardness of the support adhesive layer is greater than that of the adhesive layer.

3. The micro light-emitting chip transfer device according to claim 2, wherein The material of the support adhesive layer includes any one of UV glue and PDMS glue, and the material of the adhesive layer includes silicone gel.

4. The micro light-emitting chip transfer device according to claim 2, characterized in that The thickness of the support adhesive layer is 20μm - 50μm, and the thickness of the adhesive layer is 1μm - 2μm.

5. The micro light-emitting chip transfer device according to claim 1, characterized in that, The adhesive layer is an integral structure.

6. The micro light-emitting chip transfer device according to claim 5, wherein, The material of the adhesive layer includes any one of UV glue, PDMS glue, and silicone gel.

7. The micro light-emitting chip transfer device according to any one of claims 1-6, characterized in that A plurality of independent array units are provided on a surface of the adhesive layer away from the substrate, one array unit corresponds to one micro light-emitting chip, and each array unit includes a plurality of the bumps arranged in an array.

8. A method for manufacturing a micro light-emitting chip transfer device according to any one of claims 1-7, characterized in that, Comprising: Providing the adhesive layer on the substrate, and a plurality of the bumps are provided on a surface of the adhesive layer away from the substrate.

9. The manufacturing method of the micro light-emitting chip transfer device according to claim 8, characterized in that, The providing the adhesive layer on the substrate includes: Coating a layer of support adhesive layer on the substrate; After the support adhesive layer is cured, coating a layer of adhesive layer on the support adhesive layer; Imprinting a surface of the adhesive layer away from the substrate, and after the adhesive layer is cured, forming a plurality of the bumps on a surface of the adhesive layer away from the substrate.

10. A method for transferring a micro light-emitting chip, characterized in that, Comprising: Providing the micro light-emitting chip transfer device according to any one of claims 1 - 7; Attaching the surface of the adhesive layer away from the substrate to the surface of the micro light-emitting chip, and at least a part of the bumps of the adhesive layer are attached to the concave portions on the surface of the micro light-emitting chip in a position-aligned manner; Removing the carrier substrate of the micro light-emitting chip.

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