Substrate Preparation Method and Display Panel

Abstract

The present invention discloses a method for preparing a substrate and a display panel. The method for preparing the substrate includes: providing a substrate to be processed, the substrate to be processed having opposite first and second surfaces, and a registration mark portion being formed on the first surface; flipping the substrate to be processed so that the positions of the first surface and the second surface are interchanged; coating a photoresist on the second surface of the substrate to be processed; fixing the substrate to be processed on a fixing plate, with the first surface and the fixing plate being disposed opposite to each other, and the difference between the thicknesses of the fixing plate and the substrate to be processed being less than or equal to a preset value; aligning the exposure portion with the registration mark portion, and exposing the second surface of the substrate to be processed through the exposure portion. By setting the difference between the thickness of the fixing plate and the thickness of the substrate to be processed to be less than or equal to the preset value, it is ensured that the elevation height of the fixing plate for the registration mark portion can enable exposure focusing and positioning. The process is simple and easy to operate, effectively improving the production efficiency of the substrate.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic products, and particularly relates to a method for preparing a substrate and a display panel. Background Art

[0002] Double-sided exposure is a processing technology developed for silicon and other semiconductor substrates, aiming to fabricate photolithography patterns on both sides of the substrate and achieve mapping alignment exposure. Limited by the focusing and positioning range of existing exposure machines, accurate registration of the patterns on the front side cannot be achieved during backside exposure, which affects the production efficiency of the substrate.

[0003] Therefore, there is an urgent need for a new method for preparing a substrate and a display panel. Summary of the Invention

[0004] An embodiment of the present invention provides a method for preparing a substrate and a display panel. By setting the difference between the thickness of the fixing plate and the thickness of the substrate to be processed to be less than or equal to a preset value, it is ensured that the elevation height of the fixing plate for the alignment mark portion can enable exposure focusing and positioning. The process is simple and easy to operate, effectively improving the production efficiency of the substrate.

[0005] An embodiment of the present invention provides a method for preparing a substrate, including: providing a substrate to be processed, the substrate to be processed having opposite first and second surfaces, and an alignment mark portion being formed on the first surface; flipping the substrate to be processed so that the first surface and the second surface exchange positions; coating a photoresist on the second surface of the substrate to be processed; fixing the substrate to be processed on a fixing plate, with the first surface facing the fixing plate, and the difference between the thickness of the fixing plate and the thickness of the substrate to be processed being less than or equal to a preset value; aligning the exposure portion with the alignment mark portion, and exposing the second surface of the substrate to be processed through the exposure portion.

[0006] According to one aspect of the present invention, between the steps of providing the substrate to be processed and flipping the substrate to be processed, it further includes: coating a photoresist on the side of the alignment mark portion away from the substrate to be processed and on the portion of the first surface not covered by the alignment mark portion.

[0007] According to one aspect of the present invention, in the step of fixing the substrate to be processed on the fixing plate, it includes: the fixing plate is formed with a receiving groove for receiving the alignment mark portion, and the depth of the receiving groove is greater than or equal to the height of the alignment mark portion.

[0008] According to one aspect of the present invention, in the step of fixing the substrate to be processed on the fixing plate, it includes: the fixing plate is formed with at least one limiting member to limit the movement of the substrate to be processed through the limiting member.

[0009] According to one aspect of the present invention, the number of the limiting members is greater than or equal to two, and each of the limiting members is symmetrically distributed about the center of the receiving groove.

[0010] According to one aspect of the present invention, in the step of fixing the substrate to be processed to the fixing plate: the thicknesses of the fixing plate and the substrate to be processed are equal.

[0011] According to one aspect of the present invention, in the step of fixing the substrate to be processed to the fixing plate: the preset value is 10 μm to 20 μm.

[0012] According to one aspect of the present invention, in the step of fixing the substrate to be processed to the fixing plate, it includes: the fixing plate is a transparent plate body; preferably, the transparent plate body is transparent glass or transparent polyimide.

[0013] According to one aspect of the present invention, in the step of providing the substrate to be processed, it includes: patterning a first surface of the substrate to be processed to form a first pattern layer, and the first pattern layer includes the alignment mark portion.

[0014] Another aspect of the embodiments of the present invention provides a display panel, including: a substrate prepared by using the substrate preparation method in any one of the above embodiments.

[0015] Compared with the prior art, the substrate preparation method provided by the embodiments of the present invention needs to perform exposure on the first surface and the second surface of the substrate respectively, that is, double-sided exposure. Since the positioning and focusing range of the exposure portion is limited, the exposure portion can only focus and position the plane where the first surface is located before the substrate to be processed is flipped or the plane with a difference from the plane where the first surface is located less than or equal to the preset value. Therefore, when the substrate to be processed is flipped so that the first surface and the second surface are interchanged to expose the second surface, it is necessary to fix and raise the plane where the alignment mark portion is located through the fixing plate so that the alignment mark portion can be focused and positioned by the exposure portion. Specifically, since the second surface where the alignment mark portion is located and the first surface differ by the thickness of the substrate to be processed, by setting the difference between the thickness of the fixing plate and the thickness of the substrate to be processed to be less than or equal to the preset value, it is ensured that the raising height of the fixing plate for the alignment mark portion can enable exposure focusing and positioning, and the process is simple and easy to operate, effectively improving the production efficiency of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments of the present invention. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a flowchart of a substrate preparation method provided by an embodiment of the present invention;

[0018] Figure 2 It is a schematic structural diagram during the substrate preparation provided by an embodiment of the present invention;

[0019] Figure 3 It is a schematic structural diagram during the substrate preparation provided by another embodiment of the present invention;

[0020] Figure 4 It is a schematic structural diagram during the substrate preparation provided by yet another embodiment of the present invention;

[0021] Figure 5 It is a schematic structural diagram during the substrate preparation provided by yet another embodiment of the present invention;

[0022] Figure 6 It is a top view of a fixing plate provided by an embodiment of the present invention.

[0023] In the drawings:

[0024] 1 - substrate to be processed; 2 - alignment marking part; 3 - photoresist; 4 - fixing plate; 5 - limiting member; K - receiving groove; P1 - first surface; P2 - second surface. Detailed Description of the Invention

[0025] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by showing examples of the present invention.

[0026] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, elements defined by the statement "comprising..." do not preclude the existence of additional identical elements in the process, method, article or device comprising the said elements.

[0027] It should be understood that when describing the structure of a component, when a layer or a region is referred to as being "above" or "over" another layer or another region, it may mean directly above the other layer or another region, or there may be other layers or regions between it and the other layer or another region. And if the component is flipped, this layer or region will be "below" or "under" the other layer or another region.

[0028] Without departing from the spirit or scope of the present invention, various modifications and variations can be made to the present invention, which will be obvious to those skilled in the art. Therefore, the present invention is intended to cover modifications and variations of the present invention that fall within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided by the embodiments of the present invention can be combined with each other without contradiction.

[0029] Embodiments of the present invention provide a method for preparing a substrate and a display panel. The following will be combined with the drawings Figures 1 to 6 to describe each embodiment of the substrate preparation method and the display panel.

[0030] Please refer to Figures 1 to 5 , a method for preparing a substrate provided by an embodiment of the present invention includes:

[0031] S110: Provide a substrate 1 to be processed. The substrate 1 to be processed has opposite first surface P1 and second surface P2, and a registration mark portion 2 is formed on the first surface P1, as Figure 2 shown;

[0032] S120: Flip the substrate 1 to be processed so that the positions of the first surface P1 and the second surface P2 are interchanged,

[0033] as Figure 3 shown;

[0034] S130: Coat a photoresist 3 on the second surface P2 of the substrate 1 to be processed, asFigure 4 as shown;

[0035] S140: Fix the substrate 1 to be processed on the fixing plate 4, with the first surface P1 facing the fixing plate 4, and the difference between the thicknesses of the fixing plate 4 and the substrate 1 to be processed is less than or equal to a preset value, such as Figure 5 as shown;

[0036] S150: Align the exposure part with the alignment mark part 2, and expose the second surface P2 of the substrate 1 to be processed through the exposure part.

[0037] The substrate preparation method provided by the embodiment of the present invention needs to expose the first surface P1 and the second surface P2 of the substrate respectively, that is, double-sided exposure. Since the positioning and focusing range of the exposure part is limited, the exposure part can only focus and position the plane where the first surface P1 is located before the substrate 1 to be processed is flipped or the plane whose difference from the plane where the first surface P1 is located is less than or equal to the preset value. Therefore, when the substrate 1 to be processed is flipped so that the first surface P1 and the second surface P2 exchange positions to expose the second surface P2, it is necessary to fix and raise the plane where the alignment mark part 2 is located through the fixing plate 4 so that the alignment mark part 2 can be focused and positioned by the exposure part. Specifically, since the second surface P2 where the alignment mark part 2 is located is different from the first surface P1 by the thickness of the substrate 1 to be processed, by setting the thickness of the fixing plate 4 so that the difference from the thickness of the substrate 1 to be processed is less than or equal to the preset value, it is ensured that the height of the fixing plate 4 for raising the alignment mark part 2 can enable focusing and positioning, realizing overlay exposure. The process is simple and easy to operate, effectively improving the production efficiency of the substrate.

[0038] In step S110, the substrate 1 to be processed can be a rigid substrate, such as a glass substrate; or a flexible substrate, and its material can be polyimide, polystyrene, polyethylene terephthalate, parylene, polyethersulfone or polyethylene naphthalate. The substrate 1 to be processed can also include a conductive layer, and devices such as traces and thin film transistors are formed by means of exposure and etching.

[0039] In step S120, in order to facilitate subsequent processes such as coating, exposure, development, and etching on the second surface P2 of the substrate 1 to be processed, it is necessary to flip the substrate 1 to be processed so that the second surface P2 faces upward.

[0040] In step S130, a photoresist 3 is coated on the second surface P2 of the substrate 1 to be processed. The photoresist 3, also known as a photo resist, refers to a corrosion-resistant thin film material whose solubility changes upon irradiation or radiation by ultraviolet light, electron beam, ion beam, X-ray, etc. It is a light-sensitive liquid mixture composed of three main components: a photosensitive resin, a sensitizer, and a solvent. When processing the surface of a semiconductor material, if an appropriate and selective photoresist 3 is used, the desired image can be obtained on the surface. The photoresist 3 is classified into two major categories: positive and negative, according to the images formed. In the photoresist 3 process, after the coating is exposed and developed, the exposed part is dissolved and the unexposed part remains. This coating material is a positive photoresist 3. If the exposed part is retained and the unexposed part is dissolved, this coating material is a negative photoresist 3.

[0041] In this step, the photoresist 3 coated on the second surface P2 of the substrate 1 to be processed can be either a positive photoresist 3 or a negative photoresist 3, without any special limitation.

[0042] In step S140, the substrate 1 to be processed is fixed to the fixing plate 4, and the height of the alignment mark portion 2 on the first surface P1 is raised by the thickness of the fixing plate 4 to facilitate subsequent focusing alignment by the exposure unit.

[0043] In step S150, the exposure unit first performs focusing alignment on the alignment mark portion 2 to determine the position of the entire substrate 1 to be processed, and then uses the exposure unit to expose the second surface P2 of the substrate 1 to be processed coated with the photoresist 3, and then forms the required pattern through development and etching. Specifically, the exposure unit can perform alignment through a CCD (charge coupled device) camera.

[0044] To protect the alignment mark portion 2 and the first surface P1 of the substrate 1 to be processed, in some optional embodiments, between the steps of providing the substrate 1 to be processed and flipping the substrate 1 to be processed, it further includes: coating a photoresist 3 on the side of the alignment mark portion 2 facing away from the substrate 1 to be processed and on the part of the first surface P1 not covered by the alignment mark portion 2.

[0045] The alignment mark portion 2 and the part of the first surface P1 not covered by the alignment mark portion 2 are protected from being blocked by coating the photoresist 3, so as to avoid damage to the patterns of the alignment mark portion 2 and the first surface P1 after flipping the substrate 1 to be processed.

[0046] In some optional embodiments, in the step of fixing the substrate 1 to be processed to the fixing plate 4, it includes: the fixing plate 4 is formed with a receiving groove K for receiving the alignment mark portion 2, and the depth of the receiving groove K is greater than or equal to the height of the alignment mark portion 2.

[0047] It should be noted that since the first surface P1 of the substrate 1 to be processed has undergone patterning processes such as exposure and etching, and a patterned alignment mark portion 2 has been formed on the first surface P1. To avoid interference between the patterns formed on the first surface P1 of the substrate 1 to be processed, such as the alignment mark portion 2, and the fixing plate 4 after the substrate 1 to be processed is fixed to the fixing plate 4, resulting in damage to the alignment mark portion 2, a receiving groove K for accommodating the alignment mark portion 2 can be formed on the fixing plate 4. By making the depth of the receiving groove K greater than or equal to the height of the alignment mark portion 2, the patterns on the first surface P1 of the substrate 1 to be processed can be protected. Optionally, the shape of the receiving groove K can be circular, rectangular, or other shapes, and the shape and size of the receiving groove K can be specifically selected according to the substrate 1 to be processed and the patterns on its first surface P1. Optionally, the depth of the receiving groove K is 2 μm.

[0048] In some alternative embodiments, in the step of fixing the substrate 1 to be processed to the fixing plate 4, it includes: the orthographic projection of the fixing plate 4 on the substrate 1 to be processed is one of a circle and a polygon. The size of the fixing plate 4 can be slightly larger than the size of the substrate 1 to be processed, so as to facilitate the protection of the patterns on the first surface P1, such as the alignment mark portion 2, by the receiving groove K of the fixing plate 4, and the shape and size of the fixing plate 4 can be specifically selected according to the substrate 1 to be processed.

[0049] Please refer to Figure 6 , to avoid the substrate 1 to be processed from moving during steps such as alignment or exposure, which may affect the alignment accuracy or exposure effect. In some alternative embodiments, in the step of fixing the substrate 1 to be processed to the fixing plate 4, it includes: the fixing plate 4 is formed with at least one limiting member 5 to limit the movement of the substrate 1 to be processed through the limiting member 5.

[0050] It can be understood that the limiting member 5 can specifically adopt structural forms such as a limiting post or a baffle to fix the substrate 1 to be processed and effectively limit the movement of the substrate 1 to be processed. The limiting member 5 can be specifically arranged at the edge portion of the fixing plate 4 close to the receiving groove K to facilitate the fixation of the substrate 1 to be processed.

[0051] To further improve the stability of the fixation of the substrate 1 to be processed, in some alternative embodiments, the number of the limiting members 5 is greater than or equal to two, and the respective limiting members 5 are symmetrically distributed about the center of the receiving groove K.

[0052] In this embodiment, the respective limiting members 5 are symmetrically distributed about the center of the receiving groove K. Thus, the forces exerted on the substrate 1 to be processed by the respective limiting members 5 are evenly distributed, and can effectively prevent the substrate 1 to be processed from moving in various different directions. Optionally, four limiting members 5 are symmetrically provided on the fixing plate 4, and the substrate 1 to be processed can be stably fixed through multiple limiting members 5.

[0053] In order to achieve accurate alignment of the exposure unit with respect to the alignment mark portion 2 of the substrate 1 to be processed, in some alternative embodiments, in the step of fixing the substrate 1 to be processed to the fixing plate 4: the thicknesses of the fixing plate 4 and the substrate 1 to be processed are equal.

[0054] It should be noted that, without considering the influence of factors such as alignment errors, the plane where the exposure unit can focus for alignment and the plane where the first surface P1 of the substrate 1 to be processed is located before flipping are in the same horizontal plane. When the substrate 1 to be processed is flipped, the position where the alignment mark portion 2 is located is lower than the plane where the exposure unit can focus for alignment, and the height difference between the two is the thickness of the substrate 1 to be processed. Therefore, in the embodiments of the present invention, the fixing plate 4 is additionally provided, and the thicknesses of the fixing plate 4 and the substrate 1 to be processed are made equal to raise the alignment mark portion 2 to the same horizontal plane as the plane where the exposure unit can focus for alignment, so as to achieve the alignment of the exposure unit with respect to the alignment mark portion 2 and facilitate the subsequent exposure process. Optionally, the thicknesses of both the fixing plate 4 and the substrate 1 to be processed are 0.5 mm.

[0055] In some alternative embodiments, considering the influence of factors such as alignment errors and processing errors, in the step of fixing the substrate 1 to be processed to the fixing plate 4: the preset value is 10 μm to 20 μm.

[0056] Specifically, the thicknesses of the fixing plate 4 and the substrate 1 to be processed do not necessarily have to be equal, as long as they are within the allowable error range, that is, the difference between the thicknesses of the fixing plate 4 and the substrate 1 to be processed is less than or equal to 10 μm to 20 μm.

[0057] In order to facilitate alignment and avoid affecting the exposure effect of the substrate 1 to be processed, in some alternative embodiments, in the step of fixing the substrate 1 to be processed to the fixing plate 4, it includes: the fixing plate 4 is a transparent plate body.

[0058] Optionally, the transparent plate body is transparent glass or transparent polyimide. In order to reduce production costs, the fixing plate 4 and the substrate 1 to be processed can be formed using the same material process.

[0059] In some alternative embodiments, in the step of providing the substrate 1 to be processed, it includes: performing patterning on the first surface P1 of the substrate 1 to be processed to form a first pattern layer, and the first pattern layer includes the alignment mark portion 2.

[0060] It should be noted that the patterning specifically includes steps such as coating a photoresist 3, exposure, development, and etching to form the first pattern layer. In addition to the alignment mark portion 2, the first pattern layer may include other parts that need to be formed on the substrate, such as thin film transistors and traces.

[0061] The embodiments of the present invention also provide a display panel, including: a substrate prepared by using the substrate preparation method in any of the above embodiments.

[0062] The display panel provided by the embodiment of the present invention has the technical effects of the technical solutions of the substrates in any of the above embodiments. The same or corresponding structures and explanations of terms as those in the above embodiments will not be elaborated herein. The display panel provided by the embodiment of the present invention can be applied to mobile phones, or any electronic product with a display function, including but not limited to the following categories: televisions, laptop computers, desktop monitors, tablet computers, digital cameras, smart bracelets, smart glasses, in-vehicle displays, medical devices, industrial control devices, touch interaction terminals, etc. The embodiment of the present invention does not make special limitations in this regard.

[0063] The above is only the specific implementation manner of the present invention. Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described systems, modules, and units can refer to the corresponding processes in the foregoing method embodiments, which will not be elaborated herein. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention.

[0064] It should also be noted that the exemplary embodiments mentioned in the present invention describe some methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the above steps, that is, the steps can be executed in the order mentioned in the embodiments, or different from the order in the embodiments, or several steps can be executed simultaneously.

Claims

1. A method for preparing a substrate, characterized in that, Comprising: Providing a substrate to be processed, the substrate to be processed having opposite first and second surfaces, and a registration mark portion formed on the first surface; Flipping the substrate to be processed so that the positions of the first surface and the second surface are interchanged; Coating a photoresist on the second surface of the substrate to be processed; Fixing the substrate to be processed to a fixing plate, with the first surface and the fixing plate disposed opposite to each other, and the difference between the thicknesses of the fixing plate and the substrate to be processed being less than or equal to a preset value; Aligning the exposure portion with the registration mark portion, and exposing the second surface of the substrate to be processed through the exposure portion.

2. The substrate preparation method according to claim 1, wherein Between the steps of providing the substrate to be processed and flipping the substrate to be processed, further comprising: Coating a photoresist on the side of the registration mark portion away from the substrate to be processed and on the portion of the first surface not covered by the registration mark portion.

3. The substrate preparation method according to claim 1, wherein In the step of fixing the substrate to be processed to the fixing plate, comprising: The fixing plate is formed with a receiving groove for receiving the registration mark portion, and the depth of the receiving groove is greater than or equal to the height of the registration mark portion.

4. The substrate preparation method according to claim 3, wherein In the step of fixing the substrate to be processed to the fixing plate, comprising: The fixing plate is formed with at least one limiting member to limit the movement of the substrate to be processed through the limiting member.

5. The substrate preparation method according to claim 4, characterized in that, The number of the limiting members is greater than or equal to two, and the respective limiting members are symmetrically distributed about the center of the receiving groove.

6. The substrate preparation method according to claim 1, wherein In the step of fixing the substrate to be processed to the fixing plate: The thicknesses of the fixing plate and the substrate to be processed are equal.

7. The substrate preparation method according to claim 1, characterized in that In the step of fixing the substrate to be processed to the fixing plate: The preset value is 10 μm to 20 μm.

8. The substrate preparation method according to claim 1, wherein In the step of fixing the substrate to be processed to the fixing plate, comprising: The fixing plate is a transparent plate body.

9. The substrate preparation method according to claim 8, wherein, The transparent plate body is transparent glass or transparent polyimide.

10. The substrate preparation method according to claim 1, characterized in that, In the step of providing the substrate to be processed, comprising: Performing a patterning process on the first surface of the substrate to be processed to form a first pattern layer, the first pattern layer including the registration mark portion.

11. A display panel, characterized in that, Comprising: A substrate prepared by using the substrate preparation method according to any one of claims 1 to 10.

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