Substrate, method for manufacturing substrate, and method for transferring display chip

Abstract

The substrate, the substrate manufacturing method and the display chip transfer method provided by the embodiments of the present application relate to the technical field of display. The adhesion strengthening area for strengthening the adhesion between the substrate and the adhesive layer is arranged on the substrate. When the display chip on the adhesive layer is transferred by laser, the adhesion between the adhesive layer and the substrate is increased, so that the adhesive material in the adhesive layer is not easy to be taken away by the display chip, the probability that the adhesive material in the adhesive layer is transferred to the target substrate together with the display chip in the laser transfer process is reduced, and the display effect of the display panel manufactured by using the transferred display chip is improved.

Description

Technical Field

[0001] This application relates to the field of display technology, and more specifically, to a substrate, a method for fabricating the substrate, and a method for transferring display chips. Background Technology

[0002] Mass transfer technology refers to growing display chips (such as Micro-LED chips) on a source substrate, and then separating the display chips from the source substrate and transferring them quickly, accurately, and reliably to a target substrate, including array driving circuitry, using certain forces (such as electrostatic forces, van der Waals forces, and magnetic forces). For broader display applications such as mobile phones, tablets, and televisions, the transfer of display chips from the substrate inevitably requires mass transfer to assemble them on a larger target substrate to meet application requirements. However, due to the extremely small size and huge number of display chips transferred each time, the precision and speed requirements of the transfer process are very high, becoming one of the key factors currently restricting the mass production of Micro LEDs. Summary of the Invention

[0003] In order to overcome the technical problems mentioned in the above technical background, this application provides a substrate, a substrate fabrication method, and a display chip transfer method.

[0004] In a first aspect, this application provides a substrate substrate that carries a wafer via an adhesive layer located on one side of the substrate substrate, the wafer including a plurality of display chips;

[0005] The substrate includes an adhesion-enhancing region on the side where the adhesive layer is disposed, for enhancing the adhesion between the substrate and the adhesive layer.

[0006] In the above structure, an adhesion strengthening region is provided on the substrate to enhance the adhesion between the substrate and the adhesive layer. This can increase the adhesion between the adhesive layer and the substrate when laser transfer is performed on the display chip located on the adhesive layer, thereby reducing the probability that the adhesive material in the adhesive layer will be transferred to the target substrate along with the display chip during the laser transfer process, and improving the display effect of the display panel made from the display chip.

[0007] In one possible embodiment of this application, the adhesion strengthening region is a patterned region formed on the side of the substrate where the adhesive layer is disposed after patterning. Further, the adhesion strengthening region includes a groove recessed relative to one side of the substrate and / or a protrusion convex relative to one side of the substrate. This design increases the adhesive force between the substrate and the adhesive layer by increasing the contact area in the patterned region, thereby preventing the adhesive material in the adhesive layer from being transferred to the target substrate along with the display chip during laser transfer.

[0008] In one possible embodiment of this application, when the wafer is located on the substrate, the orthographic projection of the display chip on the substrate does not overlap with the bonding reinforcement region. This design allows for automatic alignment of the wafer bonding equipment before wafer placement and the display chip transfer equipment before display chip transfer, using the bonding reinforcement region as an alignment marker, thereby improving alignment accuracy and speed.

[0009] A second aspect of this application also provides a method for fabricating a substrate, the method comprising:

[0010] Provide a substrate;

[0011] An adhesion strengthening region is formed on one side of the substrate to enhance the adhesion between the substrate and the adhesive layer.

[0012] In one possible embodiment of this application, the step of forming an adhesion strengthening region on one side of the substrate to enhance the adhesion between the substrate and the adhesive layer includes:

[0013] A patterned region is obtained by patterning one side of the substrate, and the patterned region is used as the adhesion strengthening region.

[0014] In one possible embodiment of this application, the method further includes:

[0015] The substrate after the adhesion reinforcement region is formed is cleaned;

[0016] Preferably, the substrate is cleaned using ultraviolet light or ozone.

[0017] A third aspect of this application also provides a display chip transfer method, the method comprising:

[0018] Provide the substrate as described in the first aspect;

[0019] An adhesive layer is formed on one side of the substrate where the adhesion reinforcement area is located;

[0020] The wafer is bonded to the adhesive layer on the side away from the substrate, wherein the wafer includes a wafer substrate and a plurality of display chips located on the wafer substrate;

[0021] The wafer substrate on the wafer is peeled off, leaving a plurality of display chips spaced apart on the adhesive layer;

[0022] The plurality of display chips are transferred onto the target substrate.

[0023] In one possible embodiment of this application, the step of bonding the wafer to the adhesive layer on the side away from the substrate includes:

[0024] The wafer bonding equipment is controlled to align the wafer using the adhesion reinforcement region in the substrate as an alignment mark, and after alignment is completed, the wafer is bonded to the adhesive layer on the side away from the substrate.

[0025] Preferably, after the wafer is bonded to the adhesive layer on the side away from the substrate, the orthographic projection of the display chip in the wafer onto the substrate does not overlap with the adhesion enhancement region.

[0026] In one possible embodiment of this application, the step of peeling off the wafer substrate from the wafer and leaving a plurality of spaced-apart display chips on the adhesive layer includes:

[0027] The control stripping device strips the wafer substrate from the wafer to leave a plurality of spaced display chips on the adhesive layer.

[0028] In one possible embodiment of this application, the step of transferring the plurality of display chips onto a target substrate includes:

[0029] The control display chip transfer device uses the adhesion reinforcement region in the substrate as an alignment mark for alignment, and after the alignment is completed, picks up the plurality of display chips and transfers the plurality of display chips onto the target substrate.

[0030] This application provides a substrate, a substrate fabrication method, and a display chip transfer method. An adhesion enhancement region is provided on the substrate to strengthen the adhesion between the substrate and the adhesive layer. When laser transferring the display chip located on the adhesive layer, the adhesion between the adhesive layer and the substrate is increased, thereby reducing the probability that the adhesive material in the adhesive layer is transferred to the target substrate along with the display chip during the laser transfer process, and improving the display effect of the display panel made of the display chip. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This application provides a schematic diagram illustrating one possible structure of the substrate provided in the first embodiment.

[0033] Figure 2 An exploded view of the wafer, adhesive layer, and substrate provided in the first embodiment of this application is illustrated.

[0034] Figure 3 A second possible structural schematic diagram of the substrate provided in the first embodiment of this application is illustrated;

[0035] Figure 4 A diagram illustrating the positional relationship between the wafer, adhesive layer, and substrate provided in the first embodiment of this application is shown.

[0036] Figure 5 A schematic flowchart illustrating the substrate fabrication method provided in the second embodiment of this application is illustrated.

[0037] Figure 6 Example Figure 5 Corresponding process flow diagram;

[0038] Figure 7 A flowchart illustrating the display chip transfer method provided in the third embodiment of this application is shown;

[0039] Figure 8 Example Figure 7 The corresponding process flow diagram.

[0040] Icons: 100-Substrate; 100A-First side; 100B-Second side; 101-Groove; 102-Protrusion; 110-Adhesion reinforcement area; 200-Adhesive layer; 300-Wafer; 310-Display chip; 320-Wafer substrate; 400-Target substrate. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0044] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0045] It should be noted that, where there is no conflict, different features in the embodiments of this application can be combined with each other.

[0046] To improve the accuracy and speed of the transfer process, existing technologies generally employ laser transfer technology, using pulsed lasers to transfer display chips. However, the inventors discovered that display panels fabricated using laser transfer technology suffer from poor display quality. Further research revealed that one cause of this poor display quality is the adhesive material adhering to the display chip, which interferes with the light emitted by the chip. Analysis of the adhesive material's composition revealed that it is identical to the adhesive layer supporting the display chip before laser transfer. This means that during the laser transfer process, the display chip, along with the adhesive layer and the remaining adhesive material, is transferred to the target substrate.

[0047] To address the aforementioned technical problems, the inventors have innovatively designed the following technical solutions, which will be described in detail below with reference to the accompanying drawings. It should be noted that the deficiencies in the existing solutions are the result of the inventors' practical experience and careful research. Therefore, the discovery process of the aforementioned technical problems and the solutions proposed in the embodiments of this application below should be considered contributions made by the inventors during the invention process, and should not be construed as technical content known to those skilled in the art.

[0048] First Embodiment

[0049] To better describe the technical solution provided in this embodiment, please refer to Figure 1 and Figure 2 , Figure 1 This diagram illustrates a possible structure of the substrate 100 provided in this embodiment. Figure 2 An exploded view of the wafer, adhesive layer, and substrate provided in this embodiment is shown. Figure 1 and Figure 2 As shown, the substrate 100 includes a first side 100A and a second side 100B disposed opposite to each other. The substrate 100 carries a wafer 300 through an adhesive layer 200 located on the first side 100A. The wafer 300 includes a plurality of display chips 310. The display chips 310 can be inorganic light-emitting diodes, such as Mini LEDs or Micro LEDs.

[0050] For example, the substrate 100 can be circular, and the wafer 300 can be square, wherein the diameter of the substrate 100 is larger than the length of the long side of the wafer 300, so that the wafer 300 can be completely placed on the substrate 100 and supported by the substrate 100. In this embodiment, the first side 100A of the substrate 100 may also include an adhesion strengthening region 110 for enhancing the adhesion between the substrate 100 and the adhesive layer 200.

[0051] In this embodiment, the adhesion reinforcement region 110 may be a patterned region formed after patterning the first side 100A of the substrate 100. Exemplarily, the adhesion reinforcement region 110 may include a groove recessed relative to one side of the substrate 100, and / or a protrusion convex relative to one side of the substrate 100. Thus, by increasing the contact area between the substrate 100 and the adhesive layer 200, the adhesive force between the substrate 100 and the adhesive layer 200 can be increased.

[0052] In the first embodiment of this example, the adhesion reinforcement region 110 can be Figure 1 The patterned area shown has an adhesion reinforcement region 110 formed by a groove 101 recessed relative to the first side 100A of the substrate 100. In the adhesion reinforcement region 110, the contact area between the adhesive layer 200 and the substrate 100 is increased.

[0053] In the second embodiment of this example, the adhesion reinforcement region 110 can be Figure 3 The patterned area shown has an adhesion reinforcement region 110 formed by a protrusion 102 that protrudes outward relative to the first side 100A of the substrate 100. At the adhesion reinforcement region 110, the contact area between the adhesive layer 200 and the substrate 100 is increased.

[0054] In the third embodiment of this example, the adhesion reinforcement region 110 may also be formed by the groove 101 in the first embodiment and the protrusion 102 in the second embodiment. At the location of the adhesion reinforcement region 110, the contact area between the adhesive layer 200 and the substrate 100 is increased.

[0055] Because the adhesive layer 200 has a certain degree of fluidity, when the adhesive layer 200 is fabricated on the first side 100A of the substrate 100, the adhesive layer 200 can be fully bonded to the adhesion reinforcement region 110. At the same time, the flatness of the side of the adhesive layer 200 away from the substrate 100 can be ensured, so that the wafer 300 can be placed flat on the adhesive layer 200. In this embodiment, the adhesive layer 200 can be one of a photosensitive adhesive layer, a PDMS (polydimethylsiloxane) adhesive layer, and a polyimide film layer.

[0056] Further, please refer to Figure 4 , Figure 4 A schematic diagram of the film structure of a wafer located on a substrate is provided in an embodiment of this application. When the wafer 300 is located on the substrate 100, the orthographic projection of the display chip 310 on the substrate 100 does not overlap with the adhesion reinforcement region 110. With this design, the adhesion reinforcement region 110 can be used as an alignment mark to achieve automatic alignment of the wafer bonding equipment before wafer 300 bonding and automatic alignment of the display chip transfer equipment before display chip 310 transfer, thereby improving the accuracy and speed of wafer 300 bonding and display chip 310 transfer.

[0057] The inventors discovered through statistics that when laser transfer is used in the prior art for display chips 310, about 30% of the display chips 310 will have adhesive material adhering to them to varying degrees. The substrate 100 provided in this embodiment can control the proportion of adhesive material adhering to the display chips 310 to less than 10% when laser transfer is used for display chips 310.

[0058] In the above structure, an adhesion strengthening region 110 is provided on the substrate 100 to enhance the adhesion between the substrate 100 and the adhesive layer 200. When laser transfer is performed on the display chip 310 located on the adhesive layer 200, the adhesion between the adhesive layer 200 and the substrate 100 is increased, making it less likely that the adhesive material in the adhesive layer 200 will be carried away by the display chip 310. This reduces the probability that the adhesive material in the adhesive layer 200 will be transferred to the target substrate along with the display chip 310 during the laser transfer process, thereby improving the display effect of the display panel made using the transferred display chip 310.

[0059] Second Embodiment

[0060] Please refer to Figure 5 and Figure 6 , Figure 5A schematic flowchart illustrating the substrate fabrication method provided in the embodiments of this application is illustrated. Figure 6 Example Figure 5 The corresponding process flow diagram. (See below for details.) Figure 5 and Figure 6 The substrate fabrication method provided in this embodiment will be described in detail.

[0061] Step S11: Provide a substrate 100.

[0062] In this embodiment, the provided substrate 100 can be a glass substrate or a quartz substrate.

[0063] Step S12: An adhesion strengthening region 110 is formed on one side of the substrate 100 to enhance the adhesion between the substrate 100 and the adhesive layer 200.

[0064] In this embodiment, a patterned region can be obtained by patterning one side of the substrate 100, and the patterned region can be used as the adhesion reinforcement region 110.

[0065] In the adhesion reinforcement region 110 Figure 1 When the patterned area is shown, a groove pattern can be etched on one side of the substrate 100 relative to that side by means of etching. In the adhesion strengthening region 110... Figure 3 When the patterned area is shown, the non-adhesive reinforcement area can be thinned by etching, and the unetched area can form an outward convex pattern; or an outward convex pattern can be formed on one side of the substrate 100 by vapor deposition.

[0066] Furthermore, in this embodiment, the substrate 100 can be cleaned after the adhesion reinforcement region 110 is formed to improve the cleanliness of the substrate 100 surface, avoid the decrease in adhesion caused by unclean substrate 100 surface, and improve the adhesion between the adhesive layer 200 and the substrate 100.

[0067] Optionally, in this embodiment, the substrate 100 after forming the adhesion reinforcement region 110 can be cleaned using ultraviolet light or ozone. The inventors compared cases where cleaning was performed and found that the percentage of display chips 310 with adhesive material adhered to them (less than 3%) when the substrate 100 was cleaned was lower than the percentage of display chips 310 with adhesive material adhered to them (less than 10%) when the substrate 100 was not cleaned.

[0068] Third Embodiment

[0069] Please refer to Figure 7 and Figure 8 , Figure 7A flowchart illustrating the display chip transfer method provided in an embodiment of this application is shown. Figure 8 Example Figure 7 The corresponding process flow diagram. (See below for details.) Figure 7 and Figure 8 The display chip transfer method provided in this embodiment will be described in detail.

[0070] Step S21: Provide the substrate 100 of the first embodiment.

[0071] Step S22: An adhesive layer 200 is formed on one side of the substrate 100 where the adhesion reinforcement region 110 is located.

[0072] Step S23: The wafer 300 is bonded to the adhesive layer 200 on the side away from the substrate 100, wherein the wafer 300 includes a wafer substrate 320 and a plurality of display chips 310 located on the wafer substrate 320.

[0073] The display chip 310 can be an inorganic light-emitting diode, such as a Mini LED or a Micro LED.

[0074] Step S24: The wafer substrate 320 on the wafer 300 is peeled off, leaving a plurality of display chips 310 spaced apart on the adhesive layer 200.

[0075] Step S25: Transfer multiple display chips 310 onto the target substrate 400.

[0076] In this embodiment, in step S23, after the wafer 300 is bonded to the side of the adhesive layer 200 away from the substrate 100, the orthographic projection of the display chip 310 in the wafer 300 onto the substrate 100 does not overlap with the adhesion reinforcement region 110.

[0077] In one possible implementation of this embodiment, step S23 can be implemented in the following way.

[0078] The wafer bonding equipment is controlled to align the wafer 300 using the adhesion reinforcement region 110 in the substrate 100 as an alignment mark. After alignment is completed, the wafer 300 is bonded to the side of the adhesive layer 200 away from the substrate 100. This allows for automatic alignment through the adhesion reinforcement region 110, improving the accuracy and speed of wafer placement.

[0079] In one possible implementation of this embodiment, step S24 can be implemented in the following way.

[0080] The control stripping device peels off the wafer substrate 320 on the wafer 300 to leave a plurality of display chips 310 spaced apart on the adhesive layer 200. Exemplarily, a GaN layer may be disposed between the wafer substrates 320 and the display chips 310, and Ga and N2 may be generated in the GaN layer by laser irradiation, thereby achieving the separation of the wafer substrate 320 from the display chips 310 and removing the wafer substrate 320 from the substrate 100. In this embodiment, the stripping device may be a laser stripping device.

[0081] In one possible implementation of this embodiment, step S25 can be implemented in the following way.

[0082] The display chip transfer device uses the adhesion reinforcement region 110 in the substrate 100 as an alignment mark for alignment. After alignment, it picks up multiple display chips 310 and transfers them onto the target substrate 400. This automatic alignment via the adhesion reinforcement region 110 improves the accuracy and speed of alignment during display chip transfer. It also avoids the problem that when alignment marks are placed on the wafer substrate 320, they are not left after the wafer substrate 320 is peeled off, preventing the display chip transfer device from performing alignment during the transfer process. In this embodiment, the display chip transfer device is a laser transfer device.

[0083] In summary, the substrate, substrate fabrication method, and display chip transfer method provided in this application provide an adhesion enhancement region on the substrate to strengthen the adhesion between the substrate and the adhesive layer. This increases the adhesion between the adhesive layer and the substrate during laser transfer of the display chip located on the adhesive layer, making it less likely for the adhesive material in the adhesive layer to be carried away by the display chip. This reduces the probability that the adhesive material in the adhesive layer will be transferred to the target substrate along with the display chip during the laser transfer process, thereby improving the display effect of the display panel made using the transferred display chip.

[0084] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A substrate, characterized in that, The substrate supports the wafer via an adhesive layer located on one side of the substrate, and the wafer includes multiple display chips; The substrate includes an adhesion strengthening region on the side where the adhesive layer is disposed, for enhancing the adhesion between the substrate and the adhesive layer; The adhesion enhancement region is a patterned region formed on the side of the substrate where the adhesive layer is disposed after patterning. When the wafer is located on the substrate, the orthographic projection of the display chip on the substrate does not overlap with the adhesion reinforcement region, which serves as an alignment mark.

2. The substrate as described in claim 1, characterized in that, The adhesion-strengthening region includes a groove recessed on one side of the substrate and / or a protrusion convex on one side of the substrate.

3. A method for fabricating a substrate, characterized in that, The method includes: Provide a substrate; An adhesion reinforcement region is formed on one side of the substrate to enhance the adhesion between the substrate and the adhesive layer. The adhesion reinforcement region is a patterned region formed on the side of the substrate where the adhesive layer is disposed after patterning. When the wafer is located on the substrate, the orthographic projection of the display chip on the substrate does not overlap with the adhesion reinforcement region. The adhesion reinforcement region is used as an alignment mark.

4. The substrate fabrication method as described in claim 3, characterized in that, The method further includes: The substrate after the adhesion reinforcement region is formed is cleaned. The substrate is cleaned using ultraviolet light or ozone.

5. A method for transferring a display chip, characterized in that, The method includes: Provide a substrate according to any one of claims 1-2; An adhesive layer is formed on one side of the substrate where the adhesion reinforcement area is located; The wafer is bonded to the adhesive layer on the side away from the substrate, wherein the wafer includes a wafer substrate and a plurality of display chips located on the wafer substrate, the display chips being in contact with the adhesive layer; The wafer substrate on the wafer is peeled off, leaving a plurality of display chips spaced apart on the adhesive layer; The plurality of display chips are transferred onto the target substrate.

6. The display chip transfer method as described in claim 5, characterized in that, The step of bonding the wafer to the adhesive layer on the side away from the substrate includes: The wafer bonding equipment is controlled to align the wafer using the adhesion reinforcement region in the substrate as an alignment mark, and after alignment is completed, the wafer is bonded to the adhesive layer on the side away from the substrate. Wherein, after the wafer is bonded to the adhesive layer on the side away from the substrate, the orthographic projection of the display chip in the wafer onto the substrate does not overlap with the adhesion enhancement region.

7. The display chip transfer method as described in claim 6, characterized in that, The step of peeling off the wafer substrate from the wafer and leaving a plurality of spaced-apart display chips on the adhesive layer includes: The control stripping device strips the wafer substrate from the wafer to leave a plurality of spaced display chips on the adhesive layer.

8. The display chip transfer method as described in claim 6, characterized in that, The step of transferring the plurality of display chips onto the target substrate includes: The control display chip transfer device uses the adhesion reinforcement region in the substrate as an alignment mark for alignment, and after the alignment is completed, picks up the plurality of display chips and transfers the plurality of display chips onto the target substrate.

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