Chip assembly and method of making same, chip transfer method

Abstract

The application relates to a chip assembly and a manufacturing method and a chip transfer method thereof. In the manufactured chip assembly, each micro-LED chip is suspendedly supported on a second substrate by a support arm and a support body located at least on opposite first and second side surfaces and lapping on the bottom surface edge. When the chip is transferred, a force is only needed to be applied from the bottom surface of the micro-LED chip to the second substrate to make the support arm break, so that the micro-LED chip is separated from the second substrate, the transfer difficulty of the micro-LED chip is effectively reduced, and the chip assembly is very suitable for large-scale industrial application.

Description

Technical Field

[0001] This application relates to the field of chip transfer, and more particularly to a chip component and its manufacturing method and chip transfer method. Background Technology

[0002] Micro LED (also known as μLed) refers to chips with a size of less than 100μm. Like ordinary LEDs, they are self-emissive, and pixels are composed of LED chips with RGB colors for display. Micro LEDs have characteristics such as high resolution, low power consumption, high brightness, high contrast, high color saturation, fast response speed, thinness, and long lifespan. Each Micro LED can be addressed and driven individually, making it more energy-efficient, faster in response, and with higher brightness and saturation compared to OLEDs.

[0003] Currently, there are still many technological bottlenecks to overcome in the development of Micro LED. Due to the small size of Micro LED chips, taking a 15μm*30um Micro LED as an example, the number of Micro LEDs on a single 4-inch display panel is approximately three million. Mass transfer is a major technological hurdle limiting its development. Micro LED mass transfer technology is divided into several schools of thought based on different principles, among which van der Waals forces are the most widely used and have the greatest potential for mass production. Van der Waals forces use elastic molds to mass transfer Micro LEDs. The elastic mold uses polydimethylsiloxane (PDMS) material to create a transfer head with adhesive capabilities. The treatment of the native substrate is crucial to achieving this transfer process. For the prepared Micro LED chip to successfully adhere to and detach from the native substrate via the transfer head, the Micro LED chip needs to be fixed to the native substrate only through anchor points and broken chains. The transfer head is bonded to the Micro LED chip through van der Waals forces, and when separating the transfer head from the native substrate, the broken chains need to break so that the Micro LED chip can be transferred to the transfer head. This structure of "anchor points and break chains" is the chip's weakening structure. The quality of the weakening structure determines the quality of subsequent mass transfer.

[0004] Therefore, how to provide a weakened structure that facilitates chip transfer is an urgent problem to be solved. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a chip component and its manufacturing method and chip transfer method, aiming to solve the problem of how to provide a weakened structure that facilitates chip transfer.

[0006] This application provides a method for manufacturing a chip component, including:

[0007] A plurality of micro LED chips are fabricated on a first substrate. Each micro LED chip has a top surface, a bottom surface away from the top surface, and a first side surface and a second side surface located between the top surface and the bottom surface. The first side surface and the second side surface are two opposite sides of the micro LED chip. The bottom surface is close to the first substrate, and the electrodes of the micro LED chip are formed on the top surface.

[0008] A sacrificial layer is formed on the first substrate, the sacrificial layer covering at least one end of the electrode of each micro LED chip away from the top surface, the first side surface, and the second side surface;

[0009] The sacrificial layer and each of the micro-LED chips are transferred to the second substrate, and the first substrate is removed; the second substrate has exposed areas of the sacrificial layer in the regions of the first side and the second side of each of the micro-LED chips respectively.

[0010] On each of the exposed areas of the second substrate, a support extending toward the bottom surface of each of the micro LED chips is formed, and a support arm extending toward the bottom surface and overlapping the edge region of the bottom surface is formed from one end of the support near the bottom surface, the support arm being made of a brittle material.

[0011] After the sacrificial layer is removed, each of the micro-LED chips is suspended and supported on the second substrate by the support arm and the support body.

[0012] The above-described chip assembly fabrication method involves forming a sacrificial layer on a first substrate, covering at least one end of each micro-LED chip away from its top surface, as well as the first and second sides of the micro-LED chip. This layer is then transferred to a second substrate. The second substrate has exposed areas near the first and second sides of each micro-LED chip, and a support extending towards the bottom surface of each micro-LED chip is formed in each exposed area. A support arm is formed from one end of the support near the bottom surface of the micro-LED chip, extending towards the bottom surface of each micro-LED chip and overlapping the edge area of ​​the bottom surface. The sacrificial layer is then removed, allowing each micro-LED chip to be suspended and supported on the second substrate by the support and support arm. This creates a weakened structure, making the fabrication process simple and efficient. Furthermore, during subsequent chip transfer, since the support arm is made of a brittle material, applying an external force towards the second substrate to the bottom surface of the micro-LED chip easily breaks the support arm, allowing the micro-LED chip to detach from the second substrate. This effectively reduces the difficulty of transferring the micro-LED chip and is highly suitable for large-scale industrial applications.

[0013] Based on the same inventive concept, this application also provides a chip transfer method, comprising:

[0014] The chip assembly is manufactured using the chip assembly manufacturing method described above;

[0015] The transfer head is attached to the target micro-LED chip to be picked up in the micro-LED chip, and a force is applied toward the second substrate, causing the support arm that is attached to the target micro-LED chip to break, so as to complete the picking up of the target micro-LED chip.

[0016] The target micro-LED chip picked up by the transfer head is transferred onto the circuit board.

[0017] The chip transfer method described above can directly select the target micro LED chip to be transferred from the chip assembly with a weakened structure having a support body and a support arm. During the transfer, only a force is applied along the bottom surface of the target micro LED chip toward the second substrate to detach the target micro LED chip from the second substrate. The operation is simple, the transfer efficiency is high, and the yield is high. It is especially suitable for the mass transfer of target micro LED chips.

[0018] Based on the same inventive concept, this application also provides a chip component, including:

[0019] A second substrate, a support member disposed on the second substrate, and a micro LED chip suspended and supported on the second substrate by the support member; the micro LED chip has a top surface, a bottom surface away from the top surface, and a first side surface and a second side surface located between the top surface and the bottom surface, the first side surface and the second side surface being two opposite sides of the micro LED chip, the bottom surface being away from the second substrate, and electrodes of the micro LED chip being formed on the top surface, with a gap between the electrodes and the second substrate;

[0020] The support includes a support body disposed on the second substrate and close to the first side and the second side respectively, and a support arm extending from one end of the support body close to the bottom surface toward the bottom surface and overlapping the edge region of the bottom surface, the support arm being supported by a brittle material.

[0021] Each micro LED chip in the aforementioned chip assembly is suspended and supported on the second substrate by a weakened structure consisting of a support arm and a support body. When transferring chips, the target micro LED chip to be transferred can be directly selected from the chip assembly, and a force is applied along the bottom surface of the target micro LED chip toward the second substrate, which can detach the target micro LED chip from the second substrate. This method is simple to operate, has a high yield rate, and high transfer efficiency. Attached Figure Description

[0022] Figure 1A schematic diagram of the manufacturing process of the chip assembly provided in the embodiments of this application;

[0023] Figure 2-1 This is a schematic diagram of the distribution of micro LED chips on a first substrate provided in an embodiment of this application;

[0024] Figure 2-2 A schematic diagram of the fabrication process of the chip assembly provided in the embodiments of this application. Figure 1 ;

[0025] Figure 2-3 Schematic diagram of the sacrificial layer distribution on the first substrate provided in the embodiments of this application Figure 1 ;

[0026] Figure 2-4 Schematic diagram 2 showing the distribution of the sacrificial layer on the first substrate provided in the embodiments of this application;

[0027] Figure 2-5 Schematic diagram of the sacrificial layer distribution on the second substrate provided in the embodiments of this application. Figure 1 ;

[0028] Figure 2-6 Schematic diagram 2 of the sacrificial layer distribution on the second substrate provided in the embodiments of this application;

[0029] Figure 2-7 Schematic diagram three showing the distribution of the sacrificial layer on the second substrate provided in this application embodiment;

[0030] Figure 2-8 Schematic diagram of the support arm distribution on the second substrate provided in the embodiments of this application Figure 1 ;

[0031] Figure 2-9 Schematic diagram 2 showing the distribution of support arms on the second substrate provided in the embodiments of this application;

[0032] Figure 2-10 Schematic diagram three showing the distribution of support arms on the second substrate provided in the embodiments of this application;

[0033] Figure 2-11 A schematic diagram of the sacrificial layer removal on the second substrate provided in this application embodiment. Figure 1 ;

[0034] Figure 2-12 Schematic diagram 2 showing the removal of the sacrificial layer on the second substrate provided in this application embodiment;

[0035] Figure 2-13 Schematic diagram 3 showing the removal of the sacrificial layer on the second substrate provided in this application embodiment;

[0036] Figure 3-1 Schematic diagram 2 illustrating the manufacturing process of the chip assembly provided in this application embodiment;

[0037] Figure 3-2 Schematic diagram three showing the distribution of the sacrificial layer on the first substrate provided in the embodiments of this application;

[0038] Figure 3-3 Schematic diagram of the sacrificial layer distribution on the first substrate provided in the embodiments of this application Figure 4 ;

[0039] Figure 3-4 Schematic diagram of the sacrificial layer distribution on the first substrate provided in the embodiments of this application Figure 5 ;

[0040] Figure 4 Schematic diagram three illustrating the manufacturing process of the chip assembly provided in this application embodiment;

[0041] Figure 5 A schematic diagram of the fabrication process of the chip assembly provided in the embodiments of this application. Figure 4 ;

[0042] Figure 6-1 A schematic diagram of the structure of a chip assembly provided in another embodiment of this application. Figure 1 ;

[0043] Figure 6-2 A second schematic diagram of the structure of a chip assembly provided in another embodiment of this application;

[0044] Figure 6-3 Schematic diagram three of the chip assembly provided in another embodiment of this application;

[0045] Figure 7-1 This is a schematic flowchart of a chip transfer method provided in another embodiment of this application;

[0046] Figure 7-2 A schematic diagram of a chip transfer process provided in another embodiment of this application Figure 1 ;

[0047] Figure 8-1 A schematic diagram of the micro LED chip fabrication process provided in yet another embodiment of this application;

[0048] Figure 8-2 This is a schematic diagram of the chip assembly manufacturing process provided in yet another embodiment of this application;

[0049] Figure 8-3 Schematic diagram 2 of the chip transfer process provided in yet another embodiment of this application;

[0050] Explanation of reference numerals in the attached figures:

[0051] 1-First substrate, 2-Micro LED chip, 20-Electrode, 21-First semiconductor layer, 22-Active layer, 23-Second semiconductor layer, 24-ITO layer, 25-DBR layer, 3-Sacrificial layer, 31-Protective adhesive layer, 4-Second substrate, 51-Support, 52-Support arm, 6-Transfer head, 61-Transfer head protrusion, 7-Circuit substrate, 71-Pad area. Detailed Implementation

[0052] 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.

[0053] 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.

[0054] In related technologies, specific weakening structures need to be fabricated during the transfer of Micro LED chips. Therefore, this application aims to provide a solution that can solve the aforementioned technical problems, the details of which will be described in subsequent embodiments.

[0055] This embodiment provides a method for manufacturing a chip component, including:

[0056] S101: Fabricate several micro LED chips on the first substrate.

[0057] It should be understood that the fabrication process of the micro-LED chip on the first substrate in this embodiment is not limited. Various fabrication methods for micro-LED chips can be used. The micro-LED chip in this embodiment is, but is not limited to, a Mini LED chip, and can also be a Micro LED chip. Of course, the micro-LED chip in this embodiment can also be replaced with a larger LED chip as needed.

[0058] The micro-LED chip fabricated in this embodiment includes at least a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first and second semiconductor layers. This embodiment does not limit the specific materials of the first semiconductor layer, the second semiconductor layer, and the active layer. For example, in some applications, the first semiconductor layer can be N-type GaN, P-type GaN, or other GaAs or GaP materials, etc. Correspondingly, the second semiconductor layer can be P-type GaN, N-type GaN, or other GaAs or GaP materials, etc. In some applications, to improve conductivity and luminous efficiency, the micro-LED chip in this embodiment may also include a diffusion layer. This diffusion layer can be, but is not limited to, a transparent or semi-transparent conductive material, such as, but not limited to, an indium tin oxide (ITO) layer.

[0059] The micro-LED chip fabricated in this embodiment has a top surface, a bottom surface away from the top surface, and a first side surface and a second side surface located between the top and bottom surfaces. The bottom surface of the micro-LED chip is close to the first substrate, while the top surface is away from the first substrate. Electrodes of the micro-LED chip are provided on the top surface. The micro-LED chip in this embodiment can be a flip-chip LED chip, in which case the electrodes on the top surface include N-electrodes and P-electrodes, and the bottom surface is its main light-emitting surface. The micro-LED chip in this embodiment can also be a standard-mount LED chip, in which case the electrodes on the top surface also include N-electrodes and P-electrodes, and the top surface is its main light-emitting surface. The micro-LED chip in this embodiment can also be a vertical LED chip, in which case the electrodes on the top surface include one of N-electrodes and P-electrodes, and the bottom surface has the other of N-electrodes and P-electrodes. In this embodiment, the first and second side surfaces of the micro-LED chip are two opposite side surfaces, and the bottom surface is close to the first substrate.

[0060] In this embodiment, the first substrate can be, but is not limited to, a growth substrate, and the specific material of the growth substrate is not limited. For example, the growth substrate can be, but is not limited to, materials such as AlO, SiC, GaAs, Si, and AlGaInP. In some applications, the growth substrate can be a sapphire substrate, glass substrate, or quartz substrate with good epitaxial quality. The growth substrate is the original substrate used to fabricate micro-LED chips. The original substrate is the substrate on which the micro-LED chips are manufactured or grown, not another temporary substrate or temporary base on which the micro-LED chips have been transferred. That is, the micro-LED chips are directly fabricated on the growth substrate. However, it should be understood that the first substrate in this embodiment can also be replaced with a temporary substrate or temporary base as needed. In other words, one way to fabricate several micro-LED chips on the first substrate in this embodiment is to first fabricate several micro-LED chips on the growth substrate, and then transfer these micro-LED chips to the first substrate.

[0061] S102: A sacrificial layer is formed on the first substrate, the formed sacrificial layer covering at least the end of the electrode of each micro LED chip away from the top surface, the first side surface and the second side surface of each micro LED chip.

[0062] It should be understood that the sacrificial layer in this embodiment can be made of various materials that can be subsequently removed without damaging or affecting the normal operation of the micro-LED chip. The thickness and shape of the sacrificial layer in this embodiment can be flexibly set and are not limited. In this embodiment, the sacrificial layer can also cover at least one other surface of each micro-LED chip besides the top surface, the first side surface, and the second side surface. Furthermore, the sacrificial layer in this embodiment can be a single-layer or multi-layer structure made of one material, or a multi-layer structure made of different materials.

[0063] S103: Transfer the sacrificial layer and each micro LED chip to the second substrate, and remove the first substrate.

[0064] In one example, the sacrificial layer and each micro-LED chip can be transferred to the second substrate by aligning and bonding the front side of the second substrate with the sacrificial layer on the first substrate, thereby bonding the sacrificial layer to the front side of the second substrate (bonding can be achieved by, but is not limited to, adhesive bonding, etc.). Then, the first substrate is removed. In this embodiment, various substrate removal methods can be used for removing the first substrate, such as, but not limited to, laser lift-off; this embodiment does not impose any limitations on this method.

[0065] In this embodiment, after the sacrificial layer and each micro-LED chip are transferred to the second substrate, the areas of the second substrate near the first and second sides of each micro-LED chip have exposed areas that are exposed to the sacrificial layer. The formation method of these exposed areas in this embodiment can be flexibly configured. For example, when the sacrificial layer is formed on the first substrate, the position on the first substrate corresponding to the exposed area on the second substrate may not have a sacrificial layer formed; alternatively, when the sacrificial layer is formed on the first substrate, the sacrificial layer covers the position on the first substrate corresponding to the exposed area on the second substrate, but the sacrificial layer at that position is removed before being transferred to the second substrate, or the sacrificial layer at that position is removed after being transferred to the second substrate. The specific method used is flexible and will not be elaborated further here.

[0066] In this embodiment, the method of forming the sacrificial layer can also be flexibly set. For example, various methods such as coating and deposition can be used, but not limited to these. These will not be described in detail here.

[0067] In this embodiment, there are no specific restrictions on the material of the second substrate. For example, it can be a glass substrate, sapphire substrate, quartz substrate, etc.

[0068] S104: A support extending toward the bottom surface of each micro LED chip is formed on each exposed area of ​​the second substrate, and a support arm extending toward the bottom surface and overlapping the edge area of ​​the bottom surface is formed from one end of the support near the bottom surface of the micro LED chip. The support arm is made of a brittle material.

[0069] In this embodiment, the support formed on the second substrate extends perpendicular to the second substrate towards the bottom surface of the micro-LED chip (but it should be understood that the support can be perpendicular to the second substrate or not). The support arm in this embodiment extends laterally from the end of the support away from the second substrate (i.e., closer to the bottom surface of the micro-LED chip) towards the bottom surface of the micro-LED chip and overlaps the edge region of the bottom surface of the micro-LED chip. In this embodiment, the overlap means that the support arm is in direct contact and engagement with the bottom surface of the micro-LED chip, allowing the micro-LED chip to be suspended and supported on the second substrate through this overlap. In this embodiment, the support arm overlaps the edge region of the bottom edge of the micro-LED chip, which on the one hand meets the stability support requirements of the micro-LED chip, and on the other hand facilitates the support arm's breakage under stress during subsequent chip transfer, improving the convenience and efficiency of chip transfer.

[0070] In this embodiment, to further improve the stability of the support for the micro-LED chip and facilitate subsequent chip transfer, support bodies and support arms are formed on at least both sides of the opposite first and second sides of the micro-LED chip to support the areas of the bottom surface of the micro-LED chip near the first and second sides, respectively, making the support force on the micro-LED chip more uniform and symmetrical. Of course, when forming support bodies and support arms on only one side of the first and second sides of the micro-LED chip can also provide stable support, support bodies and support arms can be formed on only one side, thereby further simplifying the fabrication of the weakened structure, reducing costs and efficiency. Of course, in this embodiment, in addition to forming support bodies and support arms on the first and second sides of the micro-LED chip, support bodies and support arms can also be formed on at least one other side of the micro-LED chip, as long as the stable support of the micro-LED chip and the requirements for subsequent chip transfer are met, this embodiment does not impose any restrictions.

[0071] S105: Remove the sacrificial layer, and each micro LED chip is suspended and supported on the second substrate by the support arm and the support body.

[0072] In this embodiment, removing the sacrificial layer on the end of each micro-LED chip away from its top surface creates a gap between each micro-LED chip and the second substrate, allowing each micro-LED chip to be suspended and supported on the second substrate by the support body and support arm. Removing the sacrificial layer covering the first and second sides of each micro-LED chip creates a gap between the first and second sides and the support body. This allows for easy chip transfer later, where the support arm only needs to break under stress, facilitating chip pickup and improving pickup efficiency and yield.

[0073] In this embodiment, the sacrificial layer can be removed using wet, dry, or other methods depending on its specific material. These methods will not be elaborated upon further here.

[0074] It should be understood that, Figure 1 In the method for fabricating the chip assembly shown, the chip fabricated on the first substrate is a micro LED chip. The chip assembly in this embodiment is not limited to a micro LED chip, and some embodiments can also be applied to other micro semiconductor devices (that is, other micro semiconductor devices can be used to replace the micro LED chip), such as including but not limited to diodes, transistors, lasers, etc.

[0075] To facilitate understanding, this embodiment will be described below using several examples of chip component fabrication methods as examples.

[0076] Example 1: In this example, forming a sacrificial layer that covers at least the end of the electrodes of each microLED chip away from the top surface, the first side surface, and the second side surface may include: forming a sacrificial layer that covers the top surface of each microLED chip, the end of the electrodes away from the top surface, the first side surface, the second side surface, and the first substrate between adjacent microLED chips; after transferring the sacrificial layer and each microLED chip onto the second substrate, the method further includes: removing at least a portion of the sacrificial layer on the second substrate located between adjacent microLED chips, so that the regions of the second substrate adjacent to the first side surface and the second side surface of each microLED chip have exposed areas to the sacrificial layer to form exposed areas. See the example fabrication process. Figure 2-2 As shown, it includes, but is not limited to:

[0077] S201: A plurality of micro-LED chips 2 are fabricated on the first substrate 1. Each micro-LED chip 2 has a top surface T and a bottom surface D, and an electrode 20 is formed on the top surface D. (See also...) Figure 2-1 As shown, the micro LED chip 2 has opposing first side S1 and second side S2. It also has opposing third side S3 and fourth side S4. In this example, the plurality of micro LED chips 2 fabricated on the first substrate 1 are arranged in an array, with gaps between adjacent micro LED chips 2. It should be understood that the distribution of the plurality of micro LED chips 2 on the first substrate 1 is not limited to an array distribution; it can also be an alternating distribution between adjacent rows or columns or a random distribution, etc., which will not be elaborated here.

[0078] S202: A sacrificial layer 3 is formed on the first substrate 1, and the formed sacrificial layer 3 covers at least the end of the electrode 20 of each micro LED chip 2 away from the top surface, the first side surface and the second side surface of each micro LED chip 1.

[0079] See also some application scenarios in this example. Figure 2-3 As shown, the formed sacrificial layer 3 covers the top surface T of each micro LED chip 2, the end of the electrode 20 away from the top surface, the first side surface S1 and the second side surface S2 of each micro LED chip 1, and the area of ​​the first substrate 1 located between adjacent micro LED chips 2. Figure 2-3 The area between adjacent columns of micro LED chips 1 is covered, but the sacrificial layer may not cover the third side S3 and the fourth side S4 of each micro LED chip 2.

[0080] For further application scenarios in this example, see [link / reference]. Figure 2-4 As shown, it is relative to Figure 2-3 The main difference is that the sacrificial layer 3 also covers the third side S3 and the fourth side S4 of each micro LED chip 1, and covers all the areas of the first substrate 1 located between adjacent micro LED chips 2.

[0081] Figure 2-3 and Figure 2-4 In the example shown, the area of ​​the first substrate 1 near the first side S1 and the second side S2 of the micro-LED chip 2 is covered by a sacrificial layer 3. At least a portion of the sacrificial layer 3 in this area needs to be removed to allow for the exposure area of ​​the second substrate to be formed. In this example, this removal can be performed after the substrate is transferred to the second substrate. Of course, in some examples, when forming the sacrificial layer 3 on the first substrate, the sacrificial layer 3 may not cover this area, thus omitting the step of removing the sacrificial layer in this area after the substrate is transferred to the second substrate, improving manufacturing efficiency.

[0082] S203: Transfer the sacrificial layer 3 and each micro LED chip 2 onto the second substrate 4.

[0083] For example, a bonding layer that bonds with the sacrificial layer 3 can be provided on the front side of the second substrate 4 (the material of the bonding layer can be flexibly set according to the material of the sacrificial layer 3 and the specific bonding method with the sacrificial layer 3 (such as bonding or bonding, etc.), such as but not limited to adhesive layer, metal layer, etc.). Then, the side of the second substrate 4 with the bonding layer is aligned and bonded with the side of the first substrate 1 with the sacrificial layer 3, so that the sacrificial layer 3 is bonded with the bonding layer on the second substrate 4.

[0084] S204: Remove the first substrate 1.

[0085] The first substrate 1 can be removed by methods such as laser stripping, which will not be described in detail here.

[0086] S205: At least a portion of the sacrificial layer 3 located between adjacent micro-LED chips 2 on the second substrate 4 is removed so that the areas of the second substrate 4 near the first side and the second side of each micro-LED chip 2 are exposed to the sacrificial layer 3 to form exposed areas.

[0087] For example, see one application scenario. Figure 2-5 As shown, it corresponds to Figure 2-3 The sacrificial layer 3 is shown. At least a portion of the sacrificial layer 3 located between adjacent micro-LED chips 2 on the second substrate 4 is removed to form channel A, and the second substrate 4 forms an exposed area through channel A exposed to the sacrificial layer 3. In another application scenario, see... Figure 2-6 As shown, it corresponds to Figure 2-4 The sacrificial layer 3 shown is used to remove at least a portion of the sacrificial layer 3 located between adjacent micro-LED chips 2 on the second substrate 4 to form channel A. In another application scenario, see... Figure 2-7 As shown, it is relative to Figure 2-6The main difference lies in removing a portion of the sacrificial layer 3 between adjacent rows of micro LED chips 2, so that the areas of the second substrate 4 near the third and fourth sides of each micro LED chip 2 are exposed to the sacrificial layer 3 to form exposed areas.

[0088] It should be understood that if the sacrificial layer 3 is formed on the first substrate 1 and the sacrificial layer 3 does not cover the area corresponding to channel A, then step S205 can be omitted.

[0089] S206: A support body 51 extending toward the bottom surface of each micro LED chip 2 is formed on each exposed area of ​​the second substrate 4, and a support arm 52 extending toward the bottom surface and overlapping the edge area of ​​the bottom surface is formed from one end of the support body 51 near the bottom surface of the micro LED chip 2, wherein the support arm is made of a brittle material.

[0090] It should be understood that in some applications, the support body 51 and the support arm 52 may be made of the same material and may be integrally formed. In other applications, the support body 51 and the support arm 52 may be made of different materials. However, in this embodiment, the support arm 52 must be made of a brittle material, such as metal or inorganic silicon (e.g., including but not limited to silicon dioxide, silicon oxide, silicon nitride, etc.).

[0091] In this example, the support arm 52 extends laterally from one end of the support body 51 away from the second substrate 4 towards the bottom surface of the micro-LED chip 2, and overlaps the edge region of the bottom surface of the micro-LED chip 2. In this example, to further improve the stability of the support for the micro-LED chip and facilitate subsequent chip transfer, see [reference needed]. Figure 2-8 and Figure 2-9 As shown, supports and support arms 52 can be formed only on the opposite first and second sides of the micro LED chip 2 to support the areas of the bottom surface of the micro LED chip 2 near the first and second sides, respectively, making the support force on the micro LED chip 2 more uniform and symmetrical. Figure 2-8 and Figure 2-9 The main difference is that, Figure 2-8 The width W of the middle support arm 52 (see) Figure 2-11 The width of the substrate is the same as that of the micro LED chip 2. Figure 2-9 The width W of the middle support arm 52 (see) Figure 2-12 The width of the support arm 52 is smaller than that of the micro LED chip 2. Therefore, the width of the support arm 52 in this embodiment can be flexibly set, as long as it meets the support strength requirements of the micro LED chip 2. Figure 2-9 The support arm 52 shown is relative to Figure 2-8 The support arm 52 in the middle can use less material, reducing costs.

[0092] In another application scenario of this example, see Figure 2-10 (which corresponds to) Figure 2-7 As shown in the sacrificial layer 3), corresponding supports 51 and support arms 52 can also be provided on each side of the micro LED chip 2, which can further improve the stability of the support for the micro LED chip 2.

[0093] S207: The sacrificial layer 3 is removed, and each micro-LED chip 2 is suspended and supported on the second substrate 4 by the support arm 52 and the support body 51. See, for example. Figure 2-2 As shown, after the sacrificial layer 3 is removed, there are gaps between the electrodes and top surface of the micro LED chip 2 and the second substrate 4 to form a suspension. Furthermore, there are gaps between the sides (e.g., the first and second sides) of the micro LED chip 2 and the corresponding support 51, so that during subsequent chip transfer, the micro LED chip 2 can be separated from the second substrate 4 simply by breaking the support arm 52.

[0094] See one application example. Figure 2-11 As shown, it is Figure 2-8 A schematic diagram showing the result after sacrificial layer 3 has been removed. See another application example. Figure 2-12 , it is Figure 2-9 A schematic diagram showing the result after sacrificial layer 3 has been removed. See another application example. Figure 2-13 , it is Figure 2-10 A schematic diagram after the sacrificial layer 3 has been removed.

[0095] Example 2: In this example, forming a sacrificial layer that covers at least the end of the electrodes of each microLED chip away from the top surface, the first side surface, and the second side surface may include: forming a sacrificial layer that covers the top surface of each microLED chip, the end of the electrodes away from the top surface, the first side surface, the second side surface, and the first substrate between adjacent microLED chips; before transferring the sacrificial layer and each microLED chip onto the second substrate, the method further includes: removing at least a portion of the sacrificial layer on the first substrate located between adjacent microLED chips, so that at least a portion of the regions of the first substrate adjacent to the first side surface and the second side surface of each microLED chip are exposed in the sacrificial layer. See the example fabrication process. Figure 3-1 As shown, it includes, but is not limited to:

[0096] S301: Several micro LED chips 2 are fabricated on the first substrate 1.

[0097] S302: A sacrificial layer 3 is formed on the first substrate 1. The formed sacrificial layer 3 covers at least the end of the electrode 20 of each micro LED chip 2 away from the top surface, and the first and second sides of each micro LED chip 1. For details, please refer to, but are not limited to, S202 above, which will not be repeated here.

[0098] S303: Remove at least a portion of the sacrificial layer 3 on the first substrate 1 located between adjacent micro LED chips 2, so that at least a portion of the area of ​​the first substrate 1 close to the first side and the second side of each micro LED chip 2 is exposed to the sacrificial layer.

[0099] For example, see one application scenario. Figure 3-2 As shown, it corresponds to Figure 2-3 The sacrificial layer 3 is shown. At least a portion of the sacrificial layer 3 located between adjacent micro-LED chips 2 on the first substrate 1 is removed to form channel A, through which the first substrate 1 is exposed to the sacrificial layer 3. In another application scenario, see... Figure 3-3 As shown, it corresponds to Figure 2-4 The sacrificial layer 3 shown is formed by removing at least a portion of the sacrificial layer 3 located between adjacent micro-LED chips 2 on the first substrate 1. In another application scenario, see... Figure 3-4 As shown, it is relative to Figure 2-6 The main difference lies in removing a portion of the sacrificial layer 3 between adjacent rows of micro LED chips 2, so that the areas of the first substrate 1 near the third and fourth sides of each micro LED chip 2 are exposed to the sacrificial layer 3.

[0100] It should be understood that if the sacrificial layer 3 is formed on the first substrate 1 and the sacrificial layer 3 does not cover the area corresponding to channel A, then step S303 can be omitted.

[0101] S304: Transfer the sacrificial layer 3 and each micro LED chip 2 onto the second substrate 4.

[0102] S305: Remove the first substrate 1.

[0103] S306: A support body 51 extending toward the bottom surface of each micro LED chip 2 is formed on each exposed area of ​​the second substrate 4, and a support arm 52 extending toward the bottom surface and overlapping the edge region of the bottom surface is formed from one end of the support body 51 near the bottom surface of the micro LED chip 2. For example, see, but not limited to, S206 above, which will not be described again here.

[0104] S307: The sacrificial layer 3 is removed, and each micro LED chip 2 is suspended and supported on the second substrate 4 by the support arm 52 and the support body 51. For example, see, but not limited to, the above-described S207, which will not be repeated here.

[0105] See Figure 2-2 and Figure 3-1As shown in the two examples above, the support 51 and support arm 52 located at the edge of the second substrate 4 form an L-shape, with one end of the support arm 52 extending from the support 51 overlapping the bottom surface of the micro LED chip 2. The support 51 and support arm 52 located between adjacent micro LED chips 2 on the second substrate 4 form an inverted T-shape, with both ends of the support arm 52 extending from the support 51 overlapping the bottom surface of the adjacent micro LED chip 2. Of course, it should be understood that the shape of the support 51 and support arm 52 located between adjacent micro LED chips 2 on the second substrate 4 in this embodiment can also be L-shaped. That is, the shape of the support 51 and support arm 52 in this embodiment can be flexibly set, as long as it can achieve the support of the micro LED chip 2 in the above examples and facilitate the subsequent picking up of the micro LED chip 2. For example, see the manufacturing process of another chip assembly. Figure 4 As shown, it includes:

[0106] S401: Several micro LED chips 2 are fabricated on the first substrate 1.

[0107] S402: A sacrificial layer 3 is formed on the first substrate 1. The formed sacrificial layer 3 covers at least the end of the electrode 20 of each micro LED chip 2 away from the top surface, as well as the first and second sides of each micro LED chip 1. The main difference between S402 in this example and S202 and S302 above is that the sacrificial layer 3 fills the entire area between adjacent micro LED chips 2, which will not be described in detail here.

[0108] S403: At least a portion of the sacrificial layer 3 on the first substrate 1 located between adjacent micro-LED chips 2 is removed, so that at least a portion of the regions of the first substrate 1 adjacent to the first side and the second side of each micro-LED chip 2 are exposed to the sacrificial layer. The main difference between S403 and S303 in this example is that a channel A is formed in each region adjacent to the first side and the second side of the adjacent micro-LED chip 2. It should be understood that in other applications, channel A may also be formed after the substrate is transferred to the second substrate 4.

[0109] S404: Transfer the sacrificial layer 3 and each micro LED chip 2 onto the second substrate 4.

[0110] S405: Remove the first substrate 1.

[0111] S406: A support body 51 extending toward the bottom surface of each micro-LED chip 2 is formed on each exposed area of ​​the second substrate 4, and a support arm 52 extending toward the bottom surface and overlapping the edge region of the bottom surface is formed from one end of the support body 51 near the bottom surface of the micro-LED chip 2. The main difference between this example and S206 and S306 above is that the shape of the support body 51 and support arm 52 located between adjacent micro-LED chips 2 on the second substrate 4 can also be L-shaped.

[0112] S407: The sacrificial layer 3 is removed, and each micro LED chip 2 is suspended and supported on the second substrate 4 by the support arm 52 and the support body 51.

[0113] In some examples of this embodiment, the sacrificial layer may include a protective adhesive layer that can be removed by a first removal solution; in the above examples, forming a sacrificial layer that covers at least one end of the electrodes of each microLED chip away from the top surface, the first side surface, and the second side surface includes forming a protective adhesive layer that covers at least one end of the electrodes of each microLED chip away from the top surface, the first side surface, and the second side surface. In some application scenarios, the sacrificial layer may consist only of a protective adhesive layer.

[0114] In some further examples of this embodiment, the sacrificial layer may also include an inorganic silicon layer removable by the second removal solution, and the protective adhesive layer is not corroded by the second removal solution. After forming a protective adhesive layer that covers at least one end of the electrodes of each microLED chip away from the top surface, the first side surface, and the second side surface, the method further includes forming an inorganic silicon layer covering the protective adhesive layer. In this example, the inorganic silicon layer includes at least one of a silicon oxide layer (e.g., including but not limited to silicon dioxide, silicon oxynitride) and a silicon nitride layer. Using an inorganic silicon layer covering the protective adhesive layer facilitates the subsequent removal of the sacrificial layer and better avoids the sacrificial layer remaining on the second substrate or microLED chip after removal.

[0115] In some examples of this embodiment, both the support body and the support arm may be made of metal. The formation of a support body extending towards the bottom surface of each micro-LED chip on each exposed area of ​​the second substrate, and the formation of a support arm extending towards the bottom surface and overlapping the edge region of the bottom surface from the end of the support body near the bottom surface, includes: depositing (e.g., by, but not limited to, vapor deposition) a first metal layer extending towards the bottom surface of each micro-LED chip as a support body on at least each exposed area of ​​the second substrate, and depositing a second metal layer extending towards the bottom surface and overlapping the edge region of the bottom surface from the end of the first metal layer near the bottom surface as a support arm. In some specific applications, only the first metal layer extending towards the bottom surface of each micro-LED chip may be deposited on each exposed area of ​​the second substrate as a support body, and a second metal layer extending towards the bottom surface and overlapping the edge region of the bottom surface may be deposited from the end of the first metal layer near the bottom surface as a support arm. Alternatively, the second substrate may have exposed areas on each side of each micro-LED chip, with the area exposed to the sacrificial layer. A first metal layer extending towards the bottom surface of each micro-LED chip is deposited on each exposed area of ​​the second substrate (i.e., on each side of each micro-LED chip) as a support. A second metal layer extending towards the bottom surface and overlapping the edge area of ​​the bottom surface is deposited from the end of the first metal layer near the bottom surface as a support arm. For ease of understanding, this embodiment will use an example where the sacrificial layer includes a protective adhesive layer and an inorganic silicon layer, and both the support and the support arm are made of metal, to illustrate one fabrication process of the chip assembly. See [link to documentation]. Figure 5 As shown, it includes, but is not limited to:

[0116] S501: A plurality of micro LED chips 2 are fabricated on the first substrate 1, and a protective adhesive layer 31 is formed on the first substrate 1. The protective adhesive layer 31 covers at least the end of the electrode 20 of each micro LED chip 2 away from the top surface, the first side surface and the second side surface of each micro LED chip 1.

[0117] S502: An inorganic silicon layer 32 is formed on the protective adhesive layer 31.

[0118] S503: Transfer the inorganic silicon layer 32, the protective adhesive layer 31, and each micro LED chip 2 onto the second substrate 4.

[0119] S504: Remove the first substrate 1.

[0120] S505: At least a portion of the inorganic silicon layer 32 and the protective adhesive layer 31 located between adjacent micro LED chips 2 on the second substrate 4 are removed so that the areas of the second substrate 4 near the first side and the second side of each micro LED chip 2 are exposed to the inorganic silicon layer 32 and the protective adhesive layer 31 to form exposed areas.

[0121] S506: A first metal layer extending toward the bottom surface of each micro LED chip 2 is deposited on each exposed area of ​​the second substrate 4 to form a support 51, and a second metal layer extending toward the bottom surface and overlapping the edge area of ​​the bottom surface is deposited from one end of the support 51 near the bottom surface of the micro LED chip 2 to form a support arm 52.

[0122] S507: The inorganic silicon layer 32 is removed using a second removal solution.

[0123] For example, in one application scenario, when the inorganic silicon layer 32 is a silicon oxide layer, the second removal solution can be, but is not limited to, hydrofluoric acid, which corrodes away the silicon oxide.

[0124] S508: After the protective adhesive layer 31 is removed by the first removal solution, each micro LED chip 2 is suspended and supported on the second substrate 4 by the support arm 52 and the support body 51.

[0125] For example, in one application scenario, the first removal solution can be, but is not limited to, various adhesive removers, which are used to wash away the adhesive protective layer 31. The resulting support 51 and support arm 52 form a weakened structure, making the manufacturing process simple and efficient. Furthermore, during subsequent chip transfer, since the support arm 52 is made of a brittle material, only an external force needs to be applied to the bottom surface of the micro-LED chip 2 towards the second substrate 4 to easily break the support arm, thereby allowing the micro-LED chip 2 to detach from the second substrate 4. This effectively reduces the difficulty of transferring the micro-LED chip and is very suitable for large-scale industrial applications.

[0126] Another alternative embodiment:

[0127] This embodiment provides a chip assembly, comprising: a second substrate, a support member disposed on the second substrate, and a micro-LED chip suspended above the second substrate by the support member; the micro-LED chip has a top surface, a bottom surface away from the top surface, and a first side surface and a second side surface located between the top surface and the bottom surface, the first side surface and the second side surface being two opposite sides of the micro-LED chip, the bottom surface of the micro-LED chip being away from the second substrate, and electrodes of the micro-LED chip being formed on the top surface, with a gap between the electrodes of the micro-LED chip and the second substrate, i.e., the micro-LED chip is suspended above the second substrate. The support member in this embodiment includes a support body disposed on the second substrate and respectively close to the first side surface and the second side surface of the micro-LED chip, and a support arm extending from one end of the support body near the bottom surface of the micro-LED chip towards the bottom surface and overlapping the edge region of the bottom surface, the support arm being supported by a brittle material. The support body and support arm form a weakened structure for supporting and fixing the micro-LED chip. During subsequent chip transfer, since the support arm is made of a brittle material, only an external force needs to be applied to the bottom surface of the micro-LED chip towards the second substrate to easily break the support arm, thereby allowing the micro-LED chip to detach from the second substrate. This effectively reduces the difficulty of transferring the micro-LED chip and is very suitable for large-scale industrial applications. For ease of understanding, this embodiment will be described below with several examples of chip assembly structures.

[0128] See one example Figure 6-1 The chip assembly shown includes: a second substrate 4, a support member disposed on the second substrate, and a micro-LED chip 2 suspended above the second substrate 4 by the support member; an electrode 20 is formed on the top surface of the micro-LED chip 2, and there is a gap between the electrode 20 of the micro-LED chip 2 and the second substrate 4, that is, the micro-LED chip 2 is suspended above the second substrate 4. The support member includes a support body 51 disposed on the second substrate 4 and close to a first side and a second side of the micro-LED chip 2, respectively, and a support arm 52 extending from one end of the support body 51 close to the bottom surface of the micro-LED chip 2 and overlapping the edge region of the bottom surface, the support arm 52 being supported by a brittle material. In this example, there is a first gap C1 between the first side of the micro-LED chip 2 and the adjacent support body 51, and a second gap C2 between the second side of the micro-LED chip 2 and the adjacent support body 51. By setting the first gap C1 and the second gap C2, each micro-LED chip 2 has only its bottom surface touching the support arm 52, while the other areas are suspended. Therefore, during subsequent transfer of the micro-LED chips 2, only an external force needs to be applied to the bottom surface of the micro-LED chip 2 towards the second substrate 4 to easily break the support arm, thus allowing the micro-LED chip 2 to detach from the second substrate 4. (See also...) Figure 6-1In the chip assembly shown, in this example, the support body 51 and support arm 52 of the support member located at the edge of the second substrate 4 form an L-shape, with one end of the support arm 52 extending from the support body and overlapping the bottom surface of the micro LED chip 2. The support body 51 and support arm 52 of the support member located between adjacent micro LED chips 2 on the second substrate 4 form an inverted T-shape, with both ends of the support arm 52 extending from the support body 52 overlapping the bottom surface of the adjacent micro LED chip. This inverted T-shaped support arm 52 configuration allows two support arms 52 overlapping the bottom surface of adjacent micro LED chips 2 to share a single support body 51, simplifying the structure and manufacturing process while reducing material costs. Of course, it should be understood that in this embodiment, the support body 51 and support arm 52 of the support member located between adjacent micro LED chips 2 on the second substrate 4 also form an inverted L-shape, for example, see [reference needed]. Figure 6-2 As shown. It should be understood that in some other examples of this embodiment, at least one of the first gap C1 and the second gap C2 may not be provided. In this case, the first side and / or the second side of the microLED chip 2 can directly contact the adjacent support post 51. In this case, the support post 51 can also be made of a brittle material, so that pressure can be applied directly to the support post 51 to break it during chip transfer, thus completing the transfer of the microLED chip 2. Accordingly, when manufacturing such a chip assembly, based on the method shown in the above embodiment, it is only necessary to ensure that the sacrificial layer does not cover the first side and the second side of the microLED chip.

[0129] It should be understood that the micro LED chip 2 in this embodiment can be a standard LED chip or a flip-chip LED chip (see, for example, [reference needed]). Figure 6-1 and Figure 6-2 As shown, when the micro LED chip 2 is a flip chip, its bottom surface is the main light-emitting surface; when it is a top-mounted chip, its top surface (i.e., the surface with electrodes) is the main light-emitting surface. In this embodiment, the micro LED chip 2 can also be a vertical LED chip, for example, see [reference needed]. Figure 6-3 As shown, its electrodes 20 are respectively disposed on the top and bottom surfaces of the micro LED chip 2.

[0130] It should be understood that in this embodiment Figures 6-1 to 6-3 The chip assembly shown is obtained by, but is not limited to, the chip assembly fabrication method shown in the above embodiments, and may also be obtained by other methods. Figures 6-1 to 6-3 The manufacturing methods for the chip components shown will not be described in detail here.

[0131] Another alternative embodiment:

[0132] For ease of understanding, this embodiment provides a chip transfer method, which includes:

[0133] S701: Obtain the chip assembly shown in the above embodiment.

[0134] S702: The transfer head is attached to the target micro-LED chip to be picked up from the micro-LED chips on the second substrate, and a force is applied toward the second substrate to break the support arm attached to the target micro-LED chip, thereby completing the picking up of the target micro-LED chip.

[0135] It should be understood that the transfer head in this embodiment can be a transfer head capable of picking up micro LED chips. For example, according to the picking principle, it can be a transfer head of various types such as adhesive picking, magnetic picking, vacuum adsorption picking, etc.

[0136] S703: Transfer the target micro-LED chip picked up by the transfer head onto the circuit board. The circuit board in this embodiment can be, but is not limited to, various display backplanes, lighting circuit boards, etc. It can be flexibly selected according to the application scenario.

[0137] For ease of understanding, the following will use... Figure 6-1 The chip assembly shown is an example illustrating a chip transfer process. See [link to documentation]. Figure 7-2 As shown, it includes, but is not limited to:

[0138] S801: The transfer head 61 attaches to the target micro-LED chip to be picked up in the micro-LED chip 2 on the second substrate 4, and a force F is applied toward the second substrate 4, causing the support arm 52 attached to the target micro-LED chip to break (see...). Figure 7-2 (At the fracture location shown in S), to complete the pickup of the target micro LED chip.

[0139] In some applications, after the support arm 52 breaks, a portion of the support arm 52 that overlaps the bottom surface of the micro-LED chip 2 may remain on the micro-LED chip 2. Since it only overlaps the edge area of ​​the bottom surface of the micro-LED chip 2, it has virtually no impact on the normal operation and light emission efficiency of the micro-LED chip 2. In some specific applications, before transferring the target micro-LED chip picked up by the transfer head 61 onto the circuit board 7, a step of removing the support arm 52 remaining on the target micro-LED chip may also be included. The specific removal method can be flexibly set according to the specific material of the support arm 52, and will not be elaborated here.

[0140] S802: Transfer the target micro LED chip picked up by the transfer head 61 onto the circuit board 7.

[0141] S803: Completes the bonding of the target micro-LED chip to the corresponding pad 71 on the circuit board 7. The bonding can be accomplished using, but is not limited to, conductive adhesive or solder.

[0142] S804: Remove transfer head 61.

[0143] It should be understood that the specific thicknesses and dimensions of the sacrificial layer, support arm, and support body mentioned above in this embodiment can be flexibly set according to the specific application scenario. For ease of understanding, this embodiment will be described below with an example of the fabrication process of a micro LED chip with a specific structure, the fabrication process of the chip assembly containing the micro LED chip, and the subsequent chip transfer process.

[0144] For the fabrication process of a specific micro LED chip, please refer to [link / reference]. Figure 8-1 As shown, it includes, but is not limited to:

[0145] S901: Take an epitaxial wafer grown on a first substrate 1. The epitaxial wafer includes the following layers: a first semiconductor layer 21 (e.g., an N-GaN layer), an active layer 22 (e.g., MQW), and a second semiconductor layer 23 (e.g., P-GaN). Photolithographically pattern a mesa pattern on the epitaxial wafer, and then dry etch the epitaxial wafer using a method such as BCl3Cl2 as the etching gas. After removing the resist, the mesa layer (N-GaN layer) is obtained.

[0146] S902: Photolithographically pattern the ISO pattern on the mesa layer, and use a dry etching machine to etch through GaN to the substrate layer. The etching gas can be BCl3 or Cl2, and the etching depth can be, but is not limited to, 4um-8um. After removing the resist, the ISO pattern is obtained, which is the epitaxial layer of each separated micro LED chip.

[0147] S903: A whole ITO layer is sputtered on the epitaxial layer of each micro LED chip. The thickness of the whole ITO layer can be 200A-2000A. ITO pattern is photolithographically etched on the whole ITO layer. After wet etching to remove the resist, the ITO layer 24 on the epitaxial layer of each micro LED chip is obtained.

[0148] S904: A full-layer DBR (Distributed Bragg Reflection) layer is formed on the ITO layer 24 (for example, the DBR layer 25 can be formed by evaporating, but not limited to, a stack of silicon oxide and silicon nitride). The thickness of the full-layer DBR layer can be, but not limited to, 1um-4um. The DBR pattern is photolithographically etched on the full-layer DBR layer. The DBR layer is dry etched using a dry etching machine. Note that this step requires etching through the DBR layer. The etching gas can be, but not limited to, CF4 O2Ar. After removing the resist, the DBR layer 25 of each micro LED chip is obtained.

[0149] S905: A negative photoresist is used to pattern the electrode (PAD) on the DBR layer. For example, the electrode is deposited using a Fujitsu evaporation machine. The electrode thickness can be, but is not limited to, 1µm-4µm. After the blue film is stripped away, electrode 20 is obtained. The negative photoresist used in this example can have the following components: Resin: Phenolic resin (small molecular weight, fast dissolution rate); Photosensitive component: Photoacid generator (generates acid during broadband, G / line exposure); Crosslinking agent: Small molecule compounds containing multiple functional groups, such as epichlorohydrin, glutaraldehyde, N,N-methylenebisacrylamide, etc.; Solvent: PGMEA, EL. It should be understood that in some examples, a positive photoresist can be used instead of a negative photoresist, which will not be elaborated here.

[0150] based on Figure 8-1 See one example of using the fabricated micro-LED chips to create a chip assembly. Figure 8-2 As shown, it includes, but is not limited to:

[0151] S906: A protective adhesive layer 31 is coated on the first substrate 1. The protective adhesive layer 31 is not corroded by hydrofluoric acid. Its thickness can be, but is not limited to, 1µm to 10µm, and it covers at least the end of the electrode 20 of each micro LED chip 2 away from the top surface, the first side surface and the second side surface of each micro LED chip 1.

[0152] S907: An inorganic silicon layer 32 is formed on the protective adhesive layer 31. For example, a silicon oxide layer is deposited on the protective adhesive layer 31, and the silicon oxide covers the entire protective layer. The thickness can be, but is not limited to, 2000 Å-40000 Å.

[0153] S908: Transfer the inorganic silicon layer 32, the protective adhesive layer 31, and each micro LED chip 2 onto the second substrate 4; for example, a metal layer may be deposited on the second substrate 4 for bonding with the inorganic silicon layer 32.

[0154] S909: Remove the first substrate 1, for example, by laser stripping. The specific operation process can adopt the laser stripping method commonly used in the art. For example, a laser with a wavelength of 266nm can be used to thermally decompose the nitride layer between the first substrate 1 and each micro LED chip 2 to achieve the stripping of the first substrate 1.

[0155] S910: At least a portion of the inorganic silicon layer 32 and the protective adhesive layer 31 located between adjacent micro-LED chips 2 on the second substrate 4 are removed, so that the areas of the second substrate 4 near the first side and the second side of each micro-LED chip 2 have exposed areas of the inorganic silicon layer 32 and the protective adhesive layer 31. For example, a uniform photoresist layer can be formed, an exposure pattern can be created, and the inorganic silicon layer 32 and the protective adhesive layer at the connection of each micro-LED chip 2 can be etched to form a channel A, so that the areas of the second substrate 4 near the first side and the second side of each micro-LED chip 2 have exposed areas of the inorganic silicon layer 32 and the protective adhesive layer 31.

[0156] S911: A first metal layer extending toward the bottom surface of each micro LED chip 2 is formed on each exposed area of ​​the second substrate 4 by vapor deposition to form a support 51, and a second metal layer extending toward the bottom surface and overlapping the edge area of ​​the bottom surface is deposited from one end of the support 51 near the bottom surface of the micro LED chip 2 to form a support arm 52.

[0157] S912: The silicon oxide layer (i.e., inorganic silicon layer 32) is removed by hydrofluoric acid etching.

[0158] S913: After removing the protective adhesive layer 31 with adhesive remover, each micro LED chip 2 is suspended and supported on the second substrate 4 by the support arm 52 and the support body 51.

[0159] based on Figure 8-2 For the process of transferring the fabricated chip components, please refer to [link / reference]. Figure 8-3 As shown, it includes, but is not limited to:

[0160] S914-S915: The transfer head 61 is attached to the target micro-LED chip to be picked up in the micro-LED chip 2 on the second substrate 4, and a force F is applied toward the second substrate 4, causing the support arm 52 attached to the target micro-LED chip to break (see...). Figure 8-3 (The fracture location is shown in the middle S).

[0161] S916: Align and bond the target micro LED chip picked up by the transfer head 61 with the corresponding pad 71 on the circuit board 7, and complete the bonding between the target micro LED chip and the corresponding pad 71 on the circuit board 7.

[0162] S917: Removing transfer head 61 completes the chip transfer.

[0163] As can be seen, the above-described method for fabricating the weakened structure and the chip transfer method can effectively reduce the difficulty of transferring micro-devices, ensure yield, and facilitate the widespread use of micro LED chips.

[0164] Another alternative embodiment:

[0165] This embodiment also provides a display screen, including a frame and a display panel; the display panel is fixed on the frame; the display panel includes a display backplate and a plurality of micro LED chips disposed on the display backplate, wherein the plurality of micro LED chips are transferred to the display backplate by the chip transfer method described in the above embodiment. This embodiment also provides a splicing display screen, which can be formed by splicing at least two displays as shown above. This display screen and the splicing display screen can be applied to, but are not limited to, various smart mobile terminals, vehicle terminals, PCs, monitors, electronic advertising boards, etc.

[0166] It should be understood that the application of this application 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 method for manufacturing a chip component, characterized in that, include: A plurality of micro LED chips are fabricated on a first substrate. Each micro LED chip has a top surface, a bottom surface away from the top surface, and a first side surface and a second side surface located between the top surface and the bottom surface. The first side surface and the second side surface are two opposite sides of the micro LED chip. The bottom surface is close to the first substrate, and the electrodes of the micro LED chip are formed on the top surface. A sacrificial layer is formed on the first substrate, the sacrificial layer covering at least one end of the electrode of each micro LED chip away from the top surface, the first side surface, and the second side surface; The sacrificial layer and each of the micro-LED chips are transferred to the second substrate, and the first substrate is removed; the second substrate has exposed areas of the sacrificial layer in the regions of the first side and the second side of each of the micro-LED chips respectively. On each of the exposed areas of the second substrate, a support extending toward the bottom surface of each of the micro LED chips is formed, and a support arm extending toward the bottom surface and overlapping the edge region of the bottom surface is formed from one end of the support near the bottom surface, the support arm being made of a brittle material. After the sacrificial layer is removed, each of the micro-LED chips is suspended and supported on the second substrate by the support arm and the support body.

2. The method for manufacturing a chip assembly as described in claim 1, characterized in that, The sacrificial layer forming at least covers one end of each of the microLED chips away from the top surface, the first side surface, and the second side surface includes: A sacrificial layer is formed that covers the top surface of each of the micro LED chips, the end of the electrode away from the top surface, the first side surface and the second side surface, and the first substrate between adjacent micro LED chips; After transferring the sacrificial layer and each of the microLED chips onto the second substrate, the method further includes: At least a portion of the sacrificial layer on the second substrate located between adjacent microLED chips is removed, so that regions of the second substrate near the first side and the second side of each microLED chip have exposed areas to the sacrificial layer.

3. The method for manufacturing a chip assembly as described in claim 1, characterized in that, The sacrificial layer forming at least covers one end of each of the microLED chips away from the top surface, the first side surface, and the second side surface includes: A sacrificial layer is formed that covers the top surface of each of the micro LED chips, the end of the electrode away from the top surface, the first side surface and the second side surface, and the first substrate between adjacent micro LED chips; Before transferring the sacrificial layer and each of the microLED chips onto the second substrate, the method further includes: At least a portion of the sacrificial layer on the first substrate located between adjacent microLED chips is removed, so that at least a portion of the regions of the first substrate near the first side and the second side of each microLED chip are exposed to the sacrificial layer.

4. The method for manufacturing a chip assembly as described in any one of claims 1-3, characterized in that, The sacrificial layer includes a protective adhesive layer that can be removed by the first removal solution; The sacrificial layer forming at least covers one end of each of the microLED chips away from the top surface, the first side surface, and the second side surface includes: A protective adhesive layer is formed that covers at least one end of the electrodes of each of the micro LED chips away from the top surface, the first side surface, and the second side surface.

5. The method for manufacturing a chip assembly as described in claim 4, characterized in that, The sacrificial layer further includes an inorganic silicon layer that can be removed by the second removal solution, and the protective adhesive layer is not corroded by the second removal solution; After forming a protective adhesive layer that at least covers one end of each of the microLED chips away from the top surface, the first side surface, and the second side surface, the method further includes: An inorganic silicon layer is formed that covers the protective adhesive layer.

6. The method for manufacturing a chip assembly as described in any one of claims 1-3, characterized in that, The support body and the support arm are made of metal. The provision of forming a support extending toward the bottom surface of each of the micro-LED chips on each of the exposed areas of the second substrate, and forming a support arm extending toward the bottom surface and overlapping the edge region of the bottom surface from one end of the support near the bottom surface, includes: A first metal layer extending toward the bottom surface of each micro LED chip is deposited only on each of the exposed areas of the second substrate as a support, and a second metal layer extending toward the bottom surface and overlapping the edge area of ​​the bottom surface is deposited from one end of the first metal layer near the bottom surface as a support arm. Alternatively, the second substrate has exposed areas on each side of each of the micro-LED chips that are exposed to the sacrificial layer; the formation of supports extending toward the bottom surface of each of the exposed areas of the second substrate, and the formation of support arms extending toward the bottom surface and overlapping the edge region of the bottom surface from one end of the support near the bottom surface, comprising: A first metal layer extending toward the bottom surface of each micro LED chip is deposited on each of the exposed areas of the second substrate as a support, and a second metal layer extending toward the bottom surface and overlapping the edge region of the bottom surface is deposited from one end of the first metal layer near the bottom surface as a support arm.

7. A chip transfer method, characterized in that, include: The chip assembly is manufactured using the method for manufacturing a chip assembly as described in any one of claims 1-6; The transfer head is attached to the target micro-LED chip to be picked up in the micro-LED chip, and a force is applied toward the second substrate, causing the support arm that is attached to the target micro-LED chip to break, so as to complete the picking up of the target micro-LED chip. The target micro-LED chip picked up by the transfer head is transferred onto the circuit board.

8. A chip assembly, manufactured using the method for manufacturing a chip assembly as described in any one of claims 1-6, characterized in that, include: The second substrate, the support member disposed on the second substrate, and the micro LED chip suspended and supported on the second substrate by the support member. The micro LED chip has a top surface, a bottom surface away from the top surface, and a first side surface and a second side surface located between the top surface and the bottom surface. The first side surface and the second side surface are two opposite sides of the micro LED chip. The bottom surface is away from the second substrate. The electrodes of the micro LED chip are formed on the top surface. There is a gap between the electrodes and the second substrate. The support includes a support body disposed on the second substrate and close to the first side and the second side respectively, and a support arm extending from one end of the support body close to the bottom surface toward the bottom surface and overlapping the edge region of the bottom surface, the support arm being supported by a brittle material.

9. The chip assembly as described in claim 8, characterized in that, The first side has a first gap between itself and the adjacent support; and / or, the second side has a second gap between itself and the adjacent support.

10. The chip assembly as claimed in claim 8 or 9, characterized in that, The support body and the support arm of the support member located at the edge of the second substrate form an L-shape, with one end of the support arm extending from the support body overlapping the bottom surface; and / or, the support body and the support arm of the support member located between adjacent micro LED chips on the second substrate form an inverted T-shape, with both ends of the support arm extending from the support body overlapping the bottom surface of the adjacent micro LED chips respectively.

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