Device transfer substrate and preparation method thereof, and device transfer method

Abstract

The present application provides a device transfer substrate and a preparation method thereof, as well as a device transfer method, wherein in the device transfer substrate, a plurality of support units are arranged at intervals above the first base substrate; wherein each support unit includes a support column and a connecting portion arranged on the side of the support column away from the first base substrate, and an extension portion connected to the connecting portion; a plurality of components are arranged on the side of the extension portion away from the first base substrate. In the subsequent device transfer process, when the third base substrate and the device transfer substrate are aligned and pressed together, the suspended portion of the support unit (i.e., the above-mentioned extension portion) will break under the pressing action of the component and be disconnected from the corresponding connecting portion, thereby transferring the component to the third base substrate. Without the need for immature laser processing, the transfer of components can be achieved through the pressing action between substrates, which can greatly improve the process yield.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a device transfer substrate and a preparation method thereof, and a device transfer method. Background Art

[0002] With the continuous development of display technology, light emitting diode (LED) display technology, as a new display technology, has gradually become one of the research hotspots. Among them, micro light emitting diodes (Micro LED) and sub-millimeter light emitting diodes (Mini LED) with smaller sizes are increasingly being used in large-size backlights due to their small size and thin backlight thickness. Micro-LED and mini-LED technologies are based on the miniaturization of existing LEDs to below 100μm and between 100 and 300μm, respectively.

[0003] However, the manufacturing process for Mini-LED and Micro-LED is complex and challenging, particularly its key technology: mass transfer. Mass transfer for large-scale display panels requires transferring chips from a growth substrate to a small substrate, which is then transferred to a larger substrate or to a target substrate using a stamp. However, the transfer yield is low during this "small-to-large" and stamp-removal process due to the immaturity of laser processes and equipment. Furthermore, the heating step in the laser process can affect chip performance, further reducing the transfer yield. Summary of the Invention

[0004] In response to the above problems, the present application provides a device transfer substrate and its preparation method, and a device transfer method, which can solve the technical problem of low transfer yield of Micro / mini-LED display panels in the prior art.

[0005] In a first aspect, the present application provides a device transfer substrate, comprising:

[0006] a first substrate;

[0007] A plurality of support units are spaced apart and arranged above the first base substrate; wherein each support unit comprises a support column, a connecting portion arranged on a side of the support column away from the first base substrate, and an extension portion connected to the connecting portion; an orthographic projection of the extension portion on the first base substrate does not overlap an orthographic projection of the support column on the first base substrate, and the extension portion does not contact the first base substrate;

[0008] A plurality of components are arranged on a side of the extension portion away from the first base substrate.

[0009] In some embodiments, in the above-mentioned device transfer substrate, the minimum width of the gap between the orthographic projection of the component on the first substrate and the orthographic projection of the corresponding support column on the first substrate is greater than the minimum width of the gap between the orthographic projection of the component on the first substrate and the orthographic projection of the corresponding side edge of the extension portion away from the connecting portion on the first substrate;

[0010] An area ratio of an orthographic projection of the support pillar in the support unit on the first base substrate to an orthographic projection of the support unit on the first base substrate is 12.5% ​​to 15%.

[0011] In some embodiments, in the device transfer substrate, the size of the surface of the support pillar on the side close to the first substrate is the same as the size of the surface of the support pillar on the side away from the first substrate; or

[0012] The dimension of a side surface of the support column close to the first base substrate is larger than the dimension of a side surface of the support column away from the first base substrate.

[0013] In some embodiments, in the device transfer substrate, along a direction perpendicular to a surface of the first base substrate close to the support unit, a thickness of the extension portion of the support unit is greater than or equal to a height of the support column.

[0014] In some embodiments, in the device transfer substrate, the component is adhered to a side of the extension portion away from the first base substrate through a first adhesive layer.

[0015] In some embodiments, in the device transfer substrate, along a direction perpendicular to a surface of the first base substrate close to the supporting unit, a thickness of the first adhesive layer is less than a thickness of the component.

[0016] In some embodiments, in the above-mentioned device transfer substrate, an electrode pad is provided on a side of the component close to the first base substrate.

[0017] In a second aspect, the present application provides a method for preparing a device transfer substrate, comprising:

[0018] providing a first substrate;

[0019] A plurality of support units are formed above the first base substrate, each support unit comprising a support column, a connecting portion provided on a side of the support column away from the first base substrate, and an extension portion connected to the connecting portion; an orthographic projection of the extension portion on the first base substrate does not overlap an orthographic projection of the support column on the first base substrate, and the extension portion does not contact the first base substrate;

[0020] A plurality of components are arranged on a side of the extension portion away from the first base substrate.

[0021] In some embodiments, in the method for preparing the device transfer substrate, forming a plurality of spaced support units above the first substrate includes the following steps:

[0022] forming a mask layer above the first substrate;

[0023] forming a plurality of openings on the mask layer that penetrate the mask layer;

[0024] forming a support layer covering the mask layer and filling the opening; wherein the thickness of the support layer is greater than or equal to the thickness of the mask layer;

[0025] The support layer is patterned to form the plurality of support units that are spaced apart; wherein the support columns of the support units are located in the openings, and the orthographic projection of the extension portion on the first base substrate covers a portion of the orthographic projection of the mask layer on the first base substrate.

[0026] In some embodiments, in the method for preparing the device transfer substrate, disposing a plurality of components on a side of the extension portion away from the first base substrate comprises the following steps:

[0027] Providing a second substrate; wherein the second substrate comprises a second base and the plurality of components formed on the second base;

[0028] Aligning the second base substrate with the first base substrate on which the supporting unit is formed, and removing the second base from the second base substrate to transfer the component to a side of the extension away from the first base substrate;

[0029] The remaining mask layer on the first substrate is removed.

[0030] In some embodiments, in the method for preparing the device transfer substrate, before the step of aligning the second base substrate with the first base substrate having the support unit formed thereon, the method further comprises:

[0031] A first adhesive layer is formed on a side of the extension portion away from the first base substrate.

[0032] In a third aspect, the present application provides a device transfer method, comprising:

[0033] Providing a device transfer substrate as described in any one of the first aspects or a device transfer substrate prepared by the preparation method as described in any one of the second aspects;

[0034] Providing a third base substrate, wherein a second adhesive layer is provided on one side of the third base substrate;

[0035] Aligning and pressing the third base substrate and the device transfer substrate, so that the third base substrate is bonded to the side of the device transfer substrate away from the first base substrate via the second adhesive layer, and the extending portion of the supporting unit is disconnected from the corresponding connecting portion under the pressing action of the component;

[0036] The first substrate and the supporting unit are removed from the device transfer substrate to transfer the components to the third substrate.

[0037] In some embodiments, in the above device transfer method, in the transfer substrate, the component is adhered to a side of the extension away from the first base substrate via a first adhesive layer;

[0038] Removing the first substrate and the supporting unit from the device transfer substrate to transfer the components to the third substrate includes the following steps:

[0039] Removing the first base substrate, the supporting pillars and the connecting portion of the supporting unit from the device transfer substrate to transfer the components to the third base substrate;

[0040] The first adhesive layer and the extending portion that are bonded to the component are removed.

[0041] In some embodiments, in the above device transfer method, the second adhesive layer and the first adhesive layer are made of different materials.

[0042] In some embodiments, in the above device transfer method, along a direction perpendicular to a surface of the third base substrate used for alignment with the device transfer substrate, a thickness of the second adhesive layer is less than a thickness of the component.

[0043] The above technical solution can at least achieve the following technical effects:

[0044] The present application provides a device transfer substrate and its preparation method, and a device transfer method, in which a plurality of support units are arranged at intervals above the first base substrate; wherein each support unit includes a support column and a connecting portion arranged on the side of the support column away from the first base substrate, and an extension portion connected to the connecting portion; a plurality of components are arranged on the side of the extension portion away from the first base substrate. In the subsequent device transfer process, when the third base substrate and the device transfer substrate are aligned and pressed together, the suspended portion of the support unit (i.e., the above-mentioned extension portion) will break under the pressing action of the component and be disconnected from the corresponding connecting portion, thereby transferring the component to the third base substrate. In this device transfer method, there is no need for immature laser processing, and the transfer of components can be achieved through the pressing action between substrates, which can greatly improve the process yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the following detailed description, they are used to explain the present application but do not constitute a limitation of the present application. In the accompanying drawings:

[0046] Figure 1 1 is a schematic cross-sectional structural diagram of a device transfer substrate shown in an exemplary embodiment of the present application;

[0047] Figure 2 is a schematic cross-sectional structural diagram of another device transfer substrate shown in an exemplary embodiment of the present application;

[0048] Figure 3 This is a schematic flow chart of a method for preparing a device transfer substrate according to an exemplary embodiment of the present application;

[0049] Figure 4 1 is a schematic cross-sectional structural diagram of a first intermediate structure formed by relevant steps of a method for preparing a device transfer substrate according to an exemplary embodiment of the present application;

[0050] Figure 5 is a schematic cross-sectional structural diagram of a second intermediate structure formed in relevant steps of a method for preparing a device transfer substrate shown in an exemplary embodiment of the present application;

[0051] Figure 6 1 is a schematic cross-sectional view of a third intermediate structure formed in relevant steps of a method for preparing a device transfer substrate according to an exemplary embodiment of the present application;

[0052] Figure 7 is a schematic cross-sectional structure diagram of a second substrate according to an exemplary embodiment of the present application;

[0053] Figure 8 is a schematic cross-sectional structural diagram of a fourth intermediate structure formed in relevant steps of a method for preparing a device transfer substrate shown in an exemplary embodiment of the present application;

[0054] Figure 9 is a schematic cross-sectional structural diagram of a fifth intermediate structure formed in relevant steps of a method for preparing a device transfer substrate shown in an exemplary embodiment of the present application;

[0055] Figure 10 is a schematic cross-sectional structural diagram of a sixth intermediate structure formed in relevant steps of a method for preparing a device transfer substrate shown in an exemplary embodiment of the present application;

[0056] Figure 11 is a flow chart of a device transfer method shown in an exemplary embodiment of the present application;

[0057] Figure 12 is a schematic cross-sectional structure diagram of a third substrate shown in an exemplary embodiment of the present application;

[0058] Figure 13 is a schematic cross-sectional structural diagram of a first intermediate structure formed by relevant steps of a device transfer method according to an exemplary embodiment of the present application;

[0059] Figure 14 is a schematic cross-sectional structural diagram of a second intermediate structure formed by relevant steps of a device transfer method shown in an exemplary embodiment of the present application;

[0060] Figure 15 is a schematic cross-sectional structural diagram of a third intermediate structure formed by relevant steps of a device transfer method shown in an exemplary embodiment of the present application;

[0061] Figure 16 This is a schematic cross-sectional view of a product structure obtained by a device transfer method according to an exemplary embodiment of the present application;

[0062] In the drawings, like components are denoted by like reference numerals, and the drawings are not drawn to scale;

[0063] The accompanying drawings are:

[0064] 10-device transfer substrate; 11-first base substrate; 12-support unit; 121-support column; 122-connecting portion; 123-extension portion; 13-component; 13a-electrode pad; 14-first adhesive layer; 15-mask layer; 15a-opening; 16-second base substrate; 161-second substrate;

[0065] 20-third base substrate; 21-second adhesive layer;

[0066] X - the distance between two adjacent support units; a - the distance between the orthographic projection of the component on the first substrate and the orthographic projection of the corresponding support column on the first substrate; b - the distance between the orthographic projection of the component on the first substrate and the orthographic projection of the corresponding edge of the extension portion away from the connecting portion on the first substrate; d1 - the height of the support unit; d2 - the thickness of the extension portion. DETAILED DESCRIPTION

[0067] The following will describe in detail the implementation methods of the present application in conjunction with the accompanying drawings and examples, so that the implementation process of how the present application applies technical means to solve technical problems and achieve corresponding technical effects can be fully understood and implemented accordingly. The embodiments of the present application and the various features therein can be combined with each other without conflict, and the technical solutions formed are all within the scope of protection of this application. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0068] It should be understood that although the terms "first," "second," "third," etc. may be used to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Thus, a first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion without departing from the teachings of this application.

[0069] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present application. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0070] In order to fully understand the present application, detailed structures and steps will be provided in the following description to illustrate the technical solutions proposed by the present application. The preferred embodiments of the present application are described in detail below. However, in addition to these detailed descriptions, the present application may also have other implementation methods.

[0071] In the mass transfer technology for large-scale Mini-LED and Micro-LED displays, the chips on the growth substrate are transferred to a small substrate, and then the chips on the small substrate are transferred to a large substrate or to the target substrate using a stamp. However, during the "small to large" and stamp pickup process, dissociated materials are released using lasers. This requires close-packed equipment and laser release equipment for the "small to large" process. However, the laser process and equipment for dissociated materials are currently immature, resulting in low transfer yields. In addition, the heating step in the laser process affects chip performance, resulting in a reduced transfer yield.

[0072] Therefore, the present application provides a device transfer substrate 10, such as Figure 1 As shown, the device transfer substrate 10 includes a first base substrate 11 , a plurality of supporting units 12 and a plurality of components 13 .

[0073] A plurality of support units 12 are spaced apart and disposed above the first base substrate 11. Each support unit 12 includes a support column 121, a connecting portion 122 disposed on a side of the support column 121 away from the first base substrate 11, and an extension portion 123 connected to the connecting portion 122. The orthographic projection of the extension portion 123 on the first base substrate 11 does not overlap the orthographic projection of the support column 121 on the first base substrate 11, and the extension portion 123 does not contact the first base substrate 11. In other words, the extension portion 123 is a suspended portion of the support unit 12.

[0074] The plurality of components 13 are disposed on a side of the extension portion 123 away from the first base substrate 11 .

[0075] In this structure, during the subsequent device transfer process, when the target substrate and the device transfer substrate 10 are aligned and pressed together, the suspended portion of the support unit 12 (i.e., the extension portion 123) will break under the pressing action of the component 13 and disconnect from the corresponding connection portion 122, thereby transferring the component 13 to the target substrate. In this device transfer method, there is no need for immature laser processing, and the transfer of the component 13 can be achieved through the pressing action between the substrates, which reduces the heating process and can greatly improve the process yield. In addition, the material requirements and equipment requirements are reduced, the process window is larger, more reliable, and more conducive to the manufacture of large-size display devices.

[0076] In some embodiments, the minimum width (a) of the gap between the orthographic projection of the component 13 on the first base substrate 11 and the orthographic projection of the corresponding support column 121 on the first base substrate 11 is greater than the minimum width (b) of the gap between the orthographic projection of the component 13 on the first base substrate 11 and the orthographic projection of the side edge of the corresponding extension portion 123 away from the connecting portion 122 on the first base substrate 11, that is, a is greater than b.

[0077] It can be understood that in order to facilitate the alignment and pressing of the target substrate and the device transfer substrate 10 in the subsequent device transfer process, the extension portion 123 of the support unit 12 can be easily broken under the influence of shear force with the corresponding connecting portion 122 under the pressing action of the component 13, and the minimum width (a) of the gap between the orthographic projection of the component 13 on the first base substrate 11 and the orthographic projection of the corresponding support column 121 on the first base substrate 11 can be greater than the minimum width (b) of the gap between the orthographic projection of the component 13 on the first base substrate 11 and the orthographic projection of the side edge of the corresponding extension portion 123 away from the connecting portion 122 on the first base substrate 11, that is, a is greater than b, so that the extension portion 123 can be easily broken under the influence of shear force with the corresponding connecting portion 122 under the pressing action of the component 13.

[0078] In some embodiments, as Figure 1 As shown, the size of the side surface of the support column 121 close to the first base substrate 11 (i.e., the lower surface) is the same as the size of the side surface of the support column 121 away from the first base substrate 11 (i.e., the upper surface). It can be understood that the cross-sectional shape of the support column 121 in a plane perpendicular to the first base substrate 11 includes a rectangular shape.

[0079] In some embodiments, as Figure 2 As shown, the dimensions of the support column 121 on the side closest to the first substrate 11 (i.e., the lower surface) are larger than the dimensions of the support column 121 on the side farther from the first substrate 11 (i.e., the upper surface). It can be understood that, in a plane perpendicular to the first substrate 11, the cross-sectional shape of the support column 121 comprises a regular trapezoid (a trapezoid with a smaller top and a larger bottom). This structure also allows the extension portion 123 to be disconnected from the corresponding connection portion 122 under the pressure of the component 13.

[0080] In some embodiments, the dimensions of the support pillar 121 on the side closest to the first substrate 11 (i.e., the lower surface) can also be smaller than the dimensions of the support pillar 121 on the side farther from the first substrate 11 (i.e., the upper surface). It can be understood that, in a plane perpendicular to the first substrate 11, the cross-sectional shape of the support pillar 121 comprises an inverted trapezoid (a trapezoid with a larger top and a smaller bottom). This structure also allows the extension portion 123 to be disconnected from the corresponding connection portion 122 under the pressure of the component 13.

[0081] In some embodiments, an area ratio of an orthographic projection of the support pillar 121 in the support unit 12 on the first base substrate 11 to an orthographic projection of the support unit 12 on the first base substrate 11 is 12.5% ​​to 15%.

[0082] It can be understood that in order to enable the support column 121 to better support the support unit 12 and at the same time have sufficient area to form the extension portion 123, the area ratio of the orthographic projection of the support column 121 in the support unit 12 on the first base substrate 11 to the orthographic projection of the support unit 12 on the first base substrate 11 is 12.5% ​​to 15%.

[0083] The size of the support unit 12 , especially the size of the extension portion 123 , is related to the size of the component 13 . The larger the size of the component 13 , the larger the size of the extension portion 123 .

[0084] In some embodiments, there may be a one-to-one correspondence between the components 13 and the support units 12 , with one component 13 being disposed on the extension portion 123 of one support unit 12 .

[0085] Correspondingly, when there is a one-to-one correspondence between the components 13 and the support units 12 , the spacing between two adjacent support units 12 depends on the spacing of the components 13 on the initial growth substrate or the final spacing on the target substrate.

[0086] In some embodiments, the interval X between two adjacent support units 12 is greater than or equal to 5 μm.

[0087] In some embodiments, along a direction perpendicular to the surface of the first base substrate 11 close to the support unit 12 (and the upper surface shown in the figure), the thickness d2 of the extension portion 123 of the support unit 12 is greater than or equal to the height d1 of the support column 121 .

[0088] It can be understood that the support unit 12 is formed by the same film layer through a patterning process. In order to connect the support column 121 and the extension portion 123 through the connecting portion 122 so that the support column 121 can support the extension portion 123, the thickness d2 of the above-mentioned extension portion 123 can be greater than or equal to the height d1 of the support column 121.

[0089] In some embodiments, the height d1 of the support pillars 121 is 1 μm to 3 μm in a direction perpendicular to the surface of the first base substrate 11 close to the support unit 12 (and the upper surface shown in the figure). Further, the height d1 of the support pillars 121 can be 2 μm.

[0090] In some embodiments, the dimension of the support column 121 in a direction parallel to the surface of the first base substrate 11 close to the support unit 12 (i.e., the lateral dimension of the support column 121) is greater than the dimension of the support column 121 in a direction perpendicular to the surface of the first base substrate 11 close to the support unit 12 (i.e., the longitudinal height d1 of the support column 121) to ensure that the support column 121 is well connected to the first base substrate 11, so as to achieve a good supporting effect of the support column 121.

[0091] In some embodiments, the dimension of the support pillar 121 in a direction parallel to the surface of the first base substrate 11 close to the support unit 12 (i.e., the lateral dimension of the support pillar 121) is 3 μm to 10 μm. Furthermore, the lateral dimension of the support pillar 121 can be 5 μm.

[0092] In some embodiments, the component 13 is bonded to the side of the extension portion 123 away from the first base substrate 11 through the first adhesive layer 14 to prevent the component 13 from moving during the transfer process, resulting in a change in the position of the component 13 .

[0093] In some embodiments, the thickness of the first adhesive layer 14 is less than the thickness of the component 13 in a direction perpendicular to the surface of the first base substrate 11 near the support unit 12 (and the upper surface shown in the figure). The material of the first adhesive layer 14 can be a viscous organic material. During the pressing process of the target substrate and the device transfer substrate 10, the component 13 may sink into the first adhesive layer 14 under the pressing action. Therefore, to prevent the component 13 from being completely sunken in the first adhesive layer 14 and affecting the device performance, the thickness of the first adhesive layer 14 can be less than the thickness of the component 13.

[0094] Furthermore, along a direction perpendicular to the surface of the first base substrate 11 close to the support unit 12 (and the upper surface shown in the figure), the thickness of the first adhesive layer 14 is less than or equal to one third of the thickness of the component 13 .

[0095] In some embodiments, the thickness of the first adhesive layer 14 may be 1 μm to 5 μm in a direction perpendicular to the surface of the first base substrate 11 close to the support unit 12 (and the upper surface shown in the figure). Further, the thickness of the first adhesive layer 14 may be 2 μm.

[0096] In some embodiments, an electrode pad 13 a is provided on a side of the component 13 close to the first base substrate 11 .

[0097] In some embodiments, the component 13 may be a light-emitting device. It can be understood that the device transfer substrate 10 provided in this application is suitable for the transfer technology of light-emitting devices.

[0098] In some embodiments, when the component 13 is a light-emitting device, the component 13 may be a mini LED or a micro LED. Correspondingly, the electrode pad 13a of the component 13 includes an anode pad and a cathode pad.

[0099] The cross-sectional dimensions (length, width, diagonal, or diameter) of the mini LED are between approximately 100 μm and approximately 300 μm. The cross-sectional dimensions (length, width, diagonal, or diameter) of the micro LED are approximately 100 μm or less. In some embodiments, the thickness of the micro LED is 6 μm to 8 μm in a direction perpendicular to the surface of the first substrate 11 near the support unit 12 (and the upper surface shown in the figure).

[0100] Correspondingly, component 13 includes an anode layer, a light-emitting layer, and a cathode layer stacked in sequence along a direction perpendicular to the surface of first substrate 11 near support unit 12 (and the upper surface shown in the figure). The anode pad and cathode pad are electrically connected to the anode layer and cathode layer, respectively, and are used to lead out the anode layer and cathode layer, respectively.

[0101] In some embodiments, the material of the anode is a P-type GaN layer.

[0102] In some embodiments, the cathode is made of an N-type GaN layer.

[0103] In some embodiments, the material of the light-emitting layer is an InGaN multi-quantum well active layer.

[0104] In some embodiments, the light-emitting side of the component 13 is arranged opposite to the electrode pad 13a. Correspondingly, in the above-mentioned transfer substrate, the electrode pad 13a of the component 13 is located on the side of the component 13 close to the first base substrate 11, and the light-emitting side of the component 13 is located on the side of the component 13 away from the first base substrate 11.

[0105] In some embodiments, the first base substrate 11 is made of glass, quartz, sapphire, or the like.

[0106] In some embodiments, the material of the support unit 12 includes brittle non-metallic materials such as silicon dioxide and silicon nitride, or metal materials such as titanium and copper, or a laminated structure of the above materials.

[0107] The device transfer substrate 10 provided in an embodiment of the present application comprises a plurality of support units 12 spaced apart above a first base substrate 11, wherein each support unit 12 comprises a support column 121, a connection portion 122 disposed on a side of the support column 121 away from the first base substrate 11, and an extension portion 123 connected to the connection portion 122; and a plurality of components 13 are disposed on a side of the extension portion 123 away from the first base substrate 11. During the subsequent device transfer process of the device transfer substrate 10, when the target substrate and the device transfer substrate 10 are aligned and pressed together, the suspended portion of the support unit 12 (i.e., the extension portion 123) will break under the pressing action of the component 13, disconnecting from the corresponding connection portion 122, thereby transferring the component 13. During the subsequent device transfer process, the transfer of the component 13 can be achieved through the pressing action between the substrates without the need for immature laser processing, which can greatly improve the process yield.

[0108] The present application provides a method for preparing a device transfer substrate 10. The "patterning" mentioned below includes processing steps such as coating photoresist, mask exposure, development, etching, and stripping the photoresist. Specifically, the "patterning" process for patterning the photoresist includes processing steps such as coating photoresist, mask exposure, and development, but does not include etching or stripping steps. "Deposition" can be selected from any one or more of sputtering, evaporation, and chemical vapor deposition, and etching can be selected from any one or more of dry etching and wet etching.

[0109] See also Figure 3 , a device transfer substrate 10 (such as Figure 1 The method for preparing the device transfer substrate 10) shown in FIG. 1 comprises the following steps:

[0110] Step S110: providing a first base substrate 11 .

[0111] In some embodiments, the material of the first base substrate 11 includes glass, quartz, sapphire, etc.

[0112] Step S120: A plurality of support units 12 are formed above the first base substrate 11, wherein each support unit 12 includes a support column 121 and a connecting portion 122 arranged on a side of the support column 121 away from the first base substrate 11, and an extension portion 123 connected to the connecting portion 122; the orthographic projection of the extension portion 123 on the first base substrate 11 does not cover the orthographic projection of the support column 121 on the first base substrate 11, and the extension portion 123 does not contact the first base substrate 11.

[0113] The extension portion 123 is a suspended portion of the support unit 12 .

[0114] In some embodiments, in a plane perpendicular to the first base substrate 11 , a cross-sectional shape of the support pillar 121 includes a rectangle or a trapezoid.

[0115] In some embodiments, an area ratio of an orthographic projection of the support pillar 121 in the support unit 12 on the first base substrate 11 to an orthographic projection of the support unit 12 on the first base substrate 11 is 12.5% ​​to 15%.

[0116] It can be understood that in order to enable the support column 121 to better support the support unit 12 and at the same time have sufficient area to form the extension portion 123, the area ratio of the orthographic projection of the support column 121 in the support unit 12 on the first base substrate 11 to the orthographic projection of the support unit 12 on the first base substrate 11 is 12.5% ​​to 15%.

[0117] In some embodiments, along a direction perpendicular to the surface of the first base substrate 11 close to the support unit 12 (and the upper surface shown in the figure), the thickness d2 of the extension portion 123 of the support unit 12 is greater than or equal to the height d1 of the support column 121 .

[0118] In some embodiments, the height d1 of the support pillars 121 is 1 μm to 3 μm in a direction perpendicular to the surface of the first base substrate 11 close to the support unit 12 (and the upper surface shown in the figure). Further, the height d1 of the support pillars 121 can be 2 μm.

[0119] In some embodiments, the dimension of the support column 121 in a direction parallel to the surface of the first base substrate 11 close to the support unit 12 (i.e., the lateral dimension of the support column 121) is greater than the dimension of the support column 121 in a direction perpendicular to the surface of the first base substrate 11 close to the support unit 12 (i.e., the longitudinal height d1 of the support column 121) to ensure that the support column 121 is well connected to the first base substrate 11, so as to achieve a good supporting effect of the support column 121.

[0120] In some embodiments, the dimension of the support pillar 121 in a direction parallel to the surface of the first base substrate 11 close to the support unit 12 (ie, the lateral dimension of the support pillar 121 ) is 3 μm to 10 μm. Preferably, the lateral dimension of the support pillar 121 may be 5 μm.

[0121] In some embodiments, step S120 includes the following steps:

[0122] S122: forming a mask layer 15 on the first base substrate 11;

[0123] S124: If Figure 4 As shown, a plurality of openings 15a penetrating the mask layer 15 are formed on the mask layer 15;

[0124] S126: forming a support layer covering the mask layer 15 and filling the opening 15a; wherein the thickness of the support layer is greater than or equal to the thickness of the mask layer 15;

[0125] S128: Figure 5 As shown, the support layer is patterned to form a plurality of support units 12 arranged at intervals; wherein, the support column 121 of the support unit 12 is located in the opening 15a, and the orthographic projection of the extension portion 123 on the first base substrate 11 covers part of the orthographic projection of the mask layer 15 on the first base substrate 11.

[0126] The support column 121 of the support unit 12 is located in the opening 15 a , and the shape and size of the support column 121 are consistent with those of the opening 15 a .

[0127] In some embodiments, the material of the mask layer 15 includes photoresist.

[0128] The thickness of the support layer is greater than or equal to the thickness of the mask layer 15 , so that the extension portion 123 in the support unit 12 can be connected to the support column 121 through the connection portion 122 , thereby enabling the support column 121 to support the extension portion 123 .

[0129] It can be understood that since the support unit 12 is formed by forming a support layer on the first base substrate 11 and then patterning it, the intermolecular bonding force between the support column 121 of the support unit 12 and the first base substrate 11 is strong, and the support column 121 can achieve a strong supporting effect.

[0130] In some embodiments, the material of the support layer includes brittle non-metallic materials such as silicon dioxide and silicon nitride, or metal materials such as titanium and copper, or a stacked structure of the above materials.

[0131] Step S130 : disposing a plurality of components 13 on a side of the extension portion 123 away from the first base substrate 11 .

[0132] The size of the support unit 12 , especially the size of the extension portion 123 , is related to the size of the component 13 . The larger the size of the component 13 , the larger the size of the extension portion 123 .

[0133] In some embodiments, there may be a one-to-one correspondence between the components 13 and the support units 12 , with one component 13 being disposed on the extension portion 123 of one support unit 12 .

[0134] Correspondingly, when there is a one-to-one correspondence between the components 13 and the support units 12 , the spacing between two adjacent support units 12 depends on the spacing of the components 13 on the initial growth substrate or the final spacing on the target substrate.

[0135] In some embodiments, the distance between two adjacent support units 12 is greater than or equal to 5 μm.

[0136] In some embodiments, in the final transfer substrate, the minimum width (a) of the gap between the orthographic projection of the component 13 on the first base substrate 11 and the orthographic projection of the corresponding support column 121 on the first base substrate 11 is greater than the minimum width (b) of the gap between the orthographic projection of the component 13 on the first base substrate 11 and the orthographic projection of the side edge of the corresponding extension portion 123 away from the connecting portion 122 on the first base substrate 11, that is, a is greater than b, so that the extension portion 123 is easily broken under the pressure of the component 13 and the corresponding connecting portion 122 under the influence of shear force.

[0137] In some embodiments, step S130 includes the following steps:

[0138] S132: If Figure 7 As shown, a second substrate 16 is provided; wherein the second substrate 16 includes a second base 161 and a plurality of components 13 formed on the second base 161;

[0139] S134: If Figure 8 As shown, the second base substrate 16 is aligned with the first base substrate 11 having the support unit 12 formed thereon, and the second base 161 in the second base substrate 16 is removed to transfer the component 13 to the side of the extension portion 123 away from the first base substrate 11, as shown in FIG. Figure 9 As shown;

[0140] S136 : removing the remaining mask layer 15 on the first base substrate 11 .

[0141] Finally, we get Figure 1 A device transfer substrate 10 is shown.

[0142] In some embodiments, in the second base substrate 16 , the electrode pad 13 a of the component 13 is located on a side away from the second substrate 161 , so that after the component 13 is transferred to the first base substrate 11 , the electrode pad 13 a of the component 13 is located on a side close to the first base substrate 11 .

[0143] The second substrate 161 is the initial growth substrate of the component 13. When the component 13 is a light-emitting device, the light-emitting side of the component 13 is located on the side close to the second substrate 161. The second substrate 161 and the component 13 can be separated by laser stripping, polishing, etching, etc.

[0144] In some embodiments, the conditions for alignment and pressing between the second base substrate 16 and the first base substrate 11 having the support unit 12 formed thereon may be: temperature of 80° C. to 200° C., pressure of 0.3 MPa to 1.5 MPa, and vacuum of KPa level.

[0145] Preferably, the alignment and pressing conditions are a temperature of 150° C., a pressure of 0.5 MPa, and a vacuum of -100 KPa.

[0146] In some embodiments, before aligning the second base substrate 16 with the first base substrate 11 having the support unit 12 in step S134, the method may further include:

[0147] like Figure 6 As shown, a first adhesive layer 14 is formed on a side of the extension portion 123 away from the first base substrate 11 .

[0148] So that during the alignment and pressing process of the second base substrate 16 and the first base substrate 11 formed with the support unit 12, the side of the component 13 away from the second base substrate 16 is bonded to the side of the extension 123 of the support unit 12 away from the first base substrate 11 through the first adhesive layer 14, so as to prevent the component 13 from moving during the transfer process, resulting in a change in the position of the component 13.

[0149] In some embodiments, the first adhesive layer 14 can be coated on the entire surface of the first base substrate 11, and then after removing the second base 161 in the second base substrate 16 in step S134, the first adhesive layer 14 portion other than the orthographic projection of the component 13 falling thereon can be etched away by dry etching, so that the orthographic projection of the component 13 falling on the first adhesive layer 14 overlaps with the remaining portion of the first adhesive layer 14. Figure 10 The pattern of the first adhesive layer 14 is shown.

[0150] In some embodiments, the thickness of the first adhesive layer 14 is less than the thickness of the component 13 in a direction perpendicular to the surface of the first base substrate 11 near the support unit 12 (and the upper surface shown in the figure). The material of the first adhesive layer 14 can be a viscous organic material. During the pressing process of the target substrate and the device transfer substrate 10, the component 13 may sink into the first adhesive layer 14 under the pressing action. Therefore, to prevent the component 13 from being completely sunken in the first adhesive layer 14 and affecting the device performance, the thickness of the first adhesive layer 14 can be less than the thickness of the component 13.

[0151] Furthermore, along a direction perpendicular to the surface of the first base substrate 11 close to the support unit 12 (and the upper surface shown in the figure), the thickness of the first adhesive layer 14 is less than or equal to one third of the thickness of the component 13 .

[0152] In some embodiments, when the material of the mask layer 15 is photoresist, the remaining photoresist may be removed by wet etching in step S136 .

[0153] The method for preparing the device transfer substrate 10 provided in an embodiment of the present application forms a plurality of support units 12 on a first base substrate 11, and then arranges the components 13 on the side of the extension portion 123 of the support unit 12 away from the first base substrate 11. During the subsequent device transfer process, when the target substrate and the device transfer substrate 10 are aligned and pressed together, the suspended portion of the support unit 12 (i.e., the extension portion 123) will break under the pressing action of the component 13, disconnecting from the corresponding connection portion 122, thereby transferring the component 13. In the subsequent device transfer process, the transfer of the component 13 can be achieved through the pressing action between the substrates without the need for immature laser processing, which can greatly improve the process yield.

[0154] Based on the above-mentioned device transfer substrate 10, please refer to Figure 11 , a device transfer method provided in an embodiment of the present application includes the following steps:

[0155] Step S210: providing any of the above-mentioned device transfer substrates 10 or a device transfer substrate 10 prepared by any of the above-mentioned preparation methods.

[0156] Step S220: Figure 12 As shown, a third base substrate 20 is provided, wherein a second adhesive layer 21 is provided on one side of the third base substrate 20 .

[0157] Step S230: Figure 13 As shown, the third base substrate 20 and the device transfer substrate 10 are aligned and pressed together, so that the third base substrate 20 is bonded to the side of the component 13 in the device transfer substrate 10 away from the first base substrate 11 through the second adhesive layer 21, and at the same time, the extension portion 123 of the support unit 12 is disconnected from the corresponding connection portion 122 under the pressing action of the component 13, as shown in FIG. Figure 14 shown.

[0158] Step S240 : removing the first base substrate 11 and the supporting unit 12 from the device transfer substrate 10 to transfer the component 13 to the third base substrate 20 .

[0159] In some embodiments, when the electrode pad 13a of the component 13 is located on the side close to the first base substrate 11 in the transfer substrate, after the component 13 is transferred to the third base substrate 20, the electrode pad 13a of the component 13 is located on the side away from the third base substrate 20.

[0160] That is to say, it is precisely because of the special structural design of the support unit 12 in the above-mentioned device transfer substrate 10 that when the third base substrate 20 and the device transfer substrate 10 are aligned and pressed together, the suspended part of the support unit 12 (that is, the above-mentioned extension part 123) is pressed off by the component 13, causing the component 13 to be separated from the first base substrate 11, thereby realizing the transfer of the component 13.

[0161] It can be seen that in this device transfer method, there is no need for immature laser processing, and the transfer of the component 13 can be achieved through the pressing effect between the substrates, which can greatly improve the process yield.

[0162] In some embodiments, in the structure obtained after step S240, the thickness of the second adhesive layer 21 is less than the thickness of the component 13 in a direction perpendicular to the surface of the third base substrate 20 used for alignment with the device transfer substrate 10. The material of the second adhesive layer 21 can be a viscous organic material. During the pressing process of the third base substrate 20 and the device transfer substrate 10, the component 13 may sink into the second adhesive layer 21 under the pressing action. Therefore, to prevent the component 13 from being completely sunken in the second adhesive layer 21 and affecting device performance, the thickness of the second adhesive layer 21 can be less than the thickness of the component 13.

[0163] Furthermore, along a direction perpendicular to the surface of the third base substrate 20 used for alignment with the device transfer substrate 10 , the thickness of the second adhesive layer 21 is less than or equal to one third of the thickness of the component 13 .

[0164] It should be noted that since the support unit 12 is formed directly on the first base substrate 11, the intermolecular bonding force between the support column 121 of the support unit 12 and the first base substrate 11 is relatively strong. When the suspended part of the support unit 12 (i.e., the above-mentioned extension part 123) is broken, the support column 121 of the support unit 12 can achieve strong support.

[0165] During the alignment and lamination of the third substrate 20 and the device transfer substrate 10, the first substrate 11 blocks the contact between the extension 123 and the first substrate 11. At this point, there is no intermolecular bonding between the extension 123 and the first substrate 11, resulting in a simple contact relationship. Therefore, the first substrate 11 and the support pillars 121 and connecting portions 122 of the support unit 12 thereon can be removed directly.

[0166] In some embodiments, when the component 13 is fixedly connected to the extension portion 123 , the extension portion 123 may be removed by etching or the like.

[0167] In some embodiments, in the transfer substrate, the component 13 is bonded to the side of the extension portion 123 away from the first base substrate 11 through the first adhesive layer 14. Correspondingly, step S240 includes the following steps:

[0168] S242: If Figure 15 As shown, the first base substrate 11 in the device transfer substrate 10 and the support pillars 121 and the connecting portion 122 of the support unit 12 are removed to transfer the component 13 to the third base substrate 20;

[0169] S244: If Figure 16 As shown, the first adhesive layer 14 and the extension portion 123 bonded to the component 13 are removed.

[0170] In some embodiments, the extension portion 123 and the first adhesive layer 14 bonded to the component 13 can be removed by cleaning the first adhesive layer 14 with a special chemical reagent to clean the first adhesive layer 14. The extension portion 123 will then be separated from the component 13, completing the transfer of the component 13.

[0171] In some embodiments, in order to prevent the first adhesive layer 14 from affecting the second adhesive layer 21 during cleaning and causing the components 13 to fall off from the third base substrate 20, a protective layer can be used to protect the second adhesive layer 21 during cleaning of the first adhesive layer 14.

[0172] In some embodiments, different adhesive materials can also be used to prepare the first adhesive layer 14 and the second adhesive layer 21, that is, the second adhesive layer 21 is made of a different material from the first adhesive layer 14, and then the first adhesive layer 14 is removed using a solvent that can dissolve the first adhesive layer 14 but not the second adhesive layer 21.

[0173] In some embodiments, the second adhesive layer 21 and the first adhesive layer 14 can be made soluble in different solvents by adding different additives into the same substrate.

[0174] The adhesive material used for the second adhesive layer 21 and the first adhesive layer 14 may include epoxy resin, acrylic acid or polymer organic materials.

[0175] Furthermore, the entire substrate obtained after step S242 can be placed in a solvent that can dissolve the first adhesive layer 14 but not the second adhesive layer 21. After the first adhesive layer 14 is dissolved, the extension portion 123 is separated from the component 13, and the transfer of the component 13 is completed.

[0176] The device transfer method provided in the embodiments of the present application aligns and presses the third base substrate 20 and the device transfer substrate 10, so that the third base substrate 20 is bonded to the side of the device transfer substrate 10 away from the first base substrate 11 via the second adhesive layer 21. Simultaneously, the suspended portion of the support unit 12 (i.e., the aforementioned extension portion 123) is disconnected from the corresponding connection portion 122 under the pressure of the component 13, thereby achieving transfer. This device transfer method eliminates the need for immature laser processing and can achieve component 13 transfer through the pressure between the substrates, significantly improving process yield.

[0177] An embodiment of the present application further provides a display panel, which is prepared using any of the above-mentioned device transfer methods.

[0178] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. Although the implementation methods disclosed in the present application are as above, the contents are only implementation methods adopted to facilitate understanding of the present application and are not intended to limit the present application. Any technician in the technical field to which the present application belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present application, but the scope of protection of the present application shall still be based on the scope defined in the attached claims.

Claims

1. A device transfer substrate, characterized in that: include: a first substrate; A plurality of support units are spaced apart and arranged above the first base substrate; wherein each support unit comprises a support column, a connecting portion arranged on a side of the support column away from the first base substrate, and an extension portion connected to the connecting portion; an orthographic projection of the extension portion on the first base substrate does not overlap an orthographic projection of the support column on the first base substrate, and the extension portion does not contact the first base substrate; A plurality of components are arranged on a side of the extension portion away from the first substrate; The extending portion of the supporting unit will be disconnected from the corresponding connecting portion under the pressing action of the component.

2. The device transfer substrate according to claim 1, wherein: The minimum width of the gap between the orthographic projection of the component on the first substrate and the orthographic projection of the corresponding support pillar on the first substrate is greater than the minimum width of the gap between the orthographic projection of the component on the first substrate and the orthographic projection of the edge of the extending portion away from the connecting portion on the first substrate; An area ratio of an orthographic projection of the support pillar in the support unit on the first base substrate to an orthographic projection of the support unit on the first base substrate is 12.5% ​​to 15%.

3. The device transfer substrate according to claim 2, wherein: The size of the surface of the support pillar on one side close to the first substrate is the same as the size of the surface of the support pillar on one side away from the first substrate; or, The dimension of a side surface of the support column close to the first base substrate is larger than the dimension of a side surface of the support column away from the first base substrate.

4. The device transfer substrate according to claim 1, wherein: Along a direction perpendicular to a surface of the first base substrate close to the support unit, a thickness of the extension portion in the support unit is greater than or equal to a height of the support column.

5. The device transfer substrate according to claim 1, wherein The component is adhered to a side of the extension portion away from the first base substrate through a first adhesive layer.

6. The device transfer substrate according to claim 5, characterized in that Along a direction perpendicular to a surface of the first base substrate close to the supporting unit, a thickness of the first adhesive layer is less than a thickness of the component.

7. The device transfer substrate according to claim 1, wherein: An electrode pad is provided on a side of the component close to the first base substrate.

8. A method for preparing a device transfer substrate, characterized in that: include: providing a first substrate; A plurality of support units are formed above the first base substrate, each support unit comprising a support column, a connecting portion provided on a side of the support column away from the first base substrate, and an extension portion connected to the connecting portion; an orthographic projection of the extension portion on the first base substrate does not overlap an orthographic projection of the support column on the first base substrate, and the extension portion does not contact the first base substrate; Disposing a plurality of components on a side of the extension portion away from the first substrate; The extending portion of the supporting unit will be disconnected from the corresponding connecting portion under the pressing action of the component.

9. The preparation method according to claim 8, characterized in that Forming a plurality of support units spaced apart above the first base substrate comprises the following steps: forming a mask layer above the first substrate; forming a plurality of openings on the mask layer that penetrate the mask layer; forming a support layer covering the mask layer and filling the opening; wherein the thickness of the support layer is greater than or equal to the thickness of the mask layer; The support layer is patterned to form the plurality of support units that are spaced apart; wherein the support columns of the support units are located in the openings, and the orthographic projection of the extension portion on the first base substrate covers a portion of the orthographic projection of the mask layer on the first base substrate.

10. The preparation method according to claim 9, characterized in that Arranging a plurality of components on a side of the extension portion away from the first substrate includes the following steps: Providing a second substrate; wherein the second substrate comprises a second base and the plurality of components formed on the second base; Aligning the second base substrate with the first base substrate on which the supporting unit is formed, and removing the second base from the second base substrate to transfer the component to a side of the extension away from the first base substrate; The remaining mask layer on the first substrate is removed.

11. The preparation method according to claim 10, characterized in that: Before the step of aligning the second base substrate with the first base substrate having the supporting unit formed thereon, the method further includes: A first adhesive layer is formed on a side of the extension portion away from the first base substrate.

12. A device transfer method, characterized in that: include: Providing a device transfer substrate according to any one of claims 1 to 7 or a device transfer substrate prepared by the preparation method according to any one of claims 8 to 11; Providing a third base substrate, wherein a second adhesive layer is provided on one side of the third base substrate; Aligning and pressing the third base substrate and the device transfer substrate, so that the third base substrate is bonded to the side of the device transfer substrate away from the first base substrate via the second adhesive layer, and the extending portion of the supporting unit is disconnected from the corresponding connecting portion under the pressing action of the component; The first substrate and the supporting unit are removed from the device transfer substrate to transfer the components to the third substrate.

13. The device transfer method according to claim 12, wherein: In the transfer substrate, the component is adhered to the side of the extension portion away from the first base substrate through the first adhesive layer; Removing the first substrate and the supporting unit from the device transfer substrate to transfer the components to the third substrate includes the following steps: Removing the first base substrate, the supporting pillars and the connecting portion of the supporting unit from the device transfer substrate to transfer the components to the third base substrate; The first adhesive layer and the extending portion that are bonded to the component are removed.

14. The device transfer method according to claim 13, wherein: The second adhesive layer is made of a different material from the first adhesive layer.

15. The device transfer method according to claim 12, wherein: Along a direction perpendicular to a surface of the third base substrate used for alignment with the device transfer substrate, a thickness of the second adhesive layer is less than a thickness of the component.

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