Method for manufacturing a flexible display panel
By setting channels on the sacrificial layer and removing the filling material inside the channels, the problem of low chemical etching efficiency was solved, enabling efficient production of flexible display panels.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HKC CORP LTD
- Filing Date
- 2026-04-27
- Publication Date
- 2026-05-29
AI Technical Summary
In existing technologies, chemical etching methods have low etching efficiency for the sacrificial layer in flexible display panel manufacturing, which affects production efficiency.
By setting channels on the sacrificial layer and removing the filler material in the channels before chemical corrosion, the chemical corrosion solution can quickly penetrate into the interior of the sacrificial layer, thereby improving corrosion efficiency.
It significantly improves the chemical etching efficiency of the sacrificial layer and enhances the production efficiency of flexible display panels.
Smart Images
Figure CN122116762A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of display technology, and in particular to a method for preparing a flexible display panel. Background Technology
[0002] Flexible display technology, as a key direction for next-generation information display, is driving the rapid development of innovative applications such as foldable phones, wearable devices, and rollable screens. Compared to traditional rigid displays, flexible displays have advantages such as bendability, thinness, and impact resistance, making them more suitable for diverse and portable terminal needs. However, in the manufacturing process of flexible display devices, due to technical challenges such as poor stability and low alignment accuracy in key processes such as film formation, cutting, and packaging of flexible substrates, the industry generally completes the fabrication of all flexible display devices on rigid glass substrates and then separates the flexible display devices from the glass substrates.
[0003] In related technologies, a sacrificial layer is typically placed between a glass substrate and a flexible substrate and removed in subsequent processes to achieve separation between the flexible and rigid substrates. However, the currently used chemical etching method for removing the sacrificial layer suffers from low etching efficiency, which to some extent restricts production efficiency. Summary of the Invention
[0004] To address the aforementioned issues, this application provides a method for fabricating a flexible display panel that can solve the problem of low etching efficiency of the etching solution on the sacrificial layer.
[0005] To address the aforementioned problems, the first technical solution provided in this application is: a method for fabricating a flexible display panel, the method comprising the following steps: Provide rigid substrates; A sacrificial layer is prepared on one surface of a rigid substrate; wherein the sacrificial layer has channels; The trench is filled with filler material; the sacrificial layer and the filler material form a composite sacrificial layer; A flexible substrate is fabricated on the surface of the composite sacrificial layer that is away from the rigid substrate; In this case, after the flexible substrate is formed, at least some of the channels remain open to allow external media to enter the channels. The preparation method further includes: Remove the filler material from the composite sacrificial layer; The sacrificial layer is chemically etched to separate the rigid substrate from the flexible substrate.
[0006] The step of preparing a sacrificial layer on one surface of a rigid substrate includes: A sacrificial layer is prepared on one surface of a rigid substrate; The sacrificial layer is patterned to form channels on it.
[0007] The step of patterning the sacrificial layer includes: The sacrificial layer is patterned to form a plurality of first channels extending along the length direction of the sacrificial layer; wherein each first channel penetrates the sacrificial layer along both the thickness and length directions; the first channel serves as the channel on the sacrificial layer; or, The sacrificial layer is patterned to form a plurality of second channels extending along the width direction of the sacrificial layer; wherein each second channel penetrates the sacrificial layer along both the thickness and width directions; the second channel serves as the channel on the sacrificial layer; or, The sacrificial layer is patterned to form a plurality of first channels extending along the length direction of the sacrificial layer and a plurality of second channels extending along the width direction of the sacrificial layer; wherein the first channels penetrate the sacrificial layer along the thickness direction and the length direction; the second channels penetrate the sacrificial layer along the thickness direction and the width direction; and the first channels and the second channels intersect; the first channels and the second channels serve as the channels on the sacrificial layer.
[0008] Wherein, one surface of the rigid substrate has trenches; the step of preparing a sacrificial layer on one surface of the rigid substrate includes: A sacrificial layer is prepared on the trenched surface of a rigid substrate; wherein a portion of the sacrificial layer is recessed within the trench, thereby forming a channel.
[0009] The step of filling the channel with filler material includes: The trench is filled with polyvinyl alcohol, such that the surface of the polyvinyl alcohol facing away from the rigid substrate is flush with the surface of the sacrificial layer facing away from the rigid substrate; or Polymethyl methacrylate (PMMA) is filled in the channel, such that the surface of PMMA away from the rigid substrate is flush with the surface of the sacrificial layer away from the rigid substrate.
[0010] The step of fabricating a flexible substrate on the surface of the composite sacrificial layer away from the rigid substrate includes: A polyimide solution is coated on the surface of the composite sacrificial layer that is away from the rigid substrate; A first preform of a flexible substrate is formed by curing a polyimide solution. The first preform is imidized to form a flexible substrate; The filler material is polyvinyl alcohol; the step of removing the filler material from the composite sacrificial layer includes: Before imidizing the first preform, the composite sacrificial layer is placed in water at a first preset temperature to dissolve the filler material; or During the imidization of the first preform, the filler material undergoes thermal decomposition.
[0011] The step of fabricating a flexible substrate on the surface of the composite sacrificial layer away from the rigid substrate includes: A polyimide solution is coated on the surface of the composite sacrificial layer that is away from the rigid substrate; A first preform of a flexible substrate is formed by curing a polyimide solution. The first preform is imidized to form a flexible substrate; The filler material is polymethyl methacrylate; the step of removing the filler material from the composite sacrificial layer includes: During the imidization of the first preform, the filler material undergoes thermal decomposition.
[0012] The preparation method further includes: An encapsulation layer is prepared on the surface of a flexible substrate that is away from the rigid substrate.
[0013] The step of fabricating an encapsulation layer on the surface of the flexible substrate facing away from the rigid substrate includes: A silicon nitride layer is prepared on the surface of a flexible substrate that is away from the rigid substrate. A silicon oxide layer is prepared on the surface of the silicon nitride layer away from the rigid substrate.
[0014] The method further includes: A preform of a flexible display panel is formed by assembling a first composite substrate and a second composite substrate together; wherein both the first composite substrate and the second composite substrate include a rigid substrate, a sacrificial layer with channels, and a flexible substrate. The step of chemically etching the sacrificial layer includes: The preform of the flexible display panel is placed in a chemical etching environment to chemically etch the sacrificial layer.
[0015] The beneficial effect of this application is that, unlike the prior art, the method for preparing a flexible display panel provided in this application involves setting channels on the sacrificial layer and removing the filling material in the channels before performing a chemical etching process on the sacrificial layer. This allows the chemical etching substance to quickly penetrate into the interior of the sacrificial layer through the channels during the subsequent chemical etching process, thereby significantly improving the chemical etching efficiency of the sacrificial layer and thus improving the production efficiency of the flexible display panel. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 A schematic flowchart illustrating a method for fabricating a flexible display panel according to an embodiment of this application; Figure 2a for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S11 in one embodiment; Figure 2b for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S11 in another embodiment; Figure 2c for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S11 in another embodiment; Figure 3a for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S12 in one embodiment; Figure 3b for Figure 1 A schematic diagram of the intermediate product obtained after step S12 in another embodiment; Figure 3c for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S12 in another embodiment; Figure 4 for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S12 in an embodiment from a first perspective; Figure 5 for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S12 in another embodiment from a first perspective; Figure 6a for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S12 in an embodiment, viewed from a second perspective. Figure 6b for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S12 in another embodiment from a second perspective; Figure 6c for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S12 in another embodiment, viewed from a second perspective. Figure 7 for Figure 1A schematic diagram of the structure of the intermediate product obtained after step S12 in another embodiment from a second perspective; Figure 8a for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S13; Figure 8b for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S13 in another embodiment; Figure 8c for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S13 in another embodiment; Figure 8d for Figure 8c A schematic diagram of the structure after the first and second substrates are separated. Figure 9 for Figure 1 A schematic diagram of the intermediate product obtained after step S14; Figure 10 for Figure 1 A flowchart illustrating a specific embodiment of step S14; Figure 11 A schematic flowchart illustrating a method for fabricating a flexible display panel according to another embodiment of this application; Figure 12 for Figure 11 A schematic diagram of the intermediate product obtained after step S21; Figure 13 A schematic flowchart illustrating a method for fabricating a flexible display panel according to another embodiment of this application; Figure 14 for Figure 13 A schematic diagram of the intermediate product obtained after step S31; Figure 15 A schematic flowchart illustrating a method for fabricating a flexible display panel according to another embodiment of this application; Figure 16 for Figure 15 A schematic diagram of the intermediate product obtained after step S41; Figure 17 A schematic flowchart illustrating the fabrication method of a flexible display panel provided in other embodiments of this application; Figure 18 for Figure 17 A schematic diagram of the structure of the intermediate product obtained after step S51.
[0017] Label Explanation: 10-Rigid substrate; 11-Trench; 101-First substrate; 102-Second substrate; 103-Through hole; 20-Sacrificial layer; 21-Channel; 30-Filling material; 40-Composite sacrificial layer; 50-Flexible substrate; 60-Encapsulation layer; 70-Common electrode; 80-Drive circuit layer; 90-Display layer; 100-First composite substrate; 200-Second composite substrate. Detailed Implementation
[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0019] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.
[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0021] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.
[0022] The present application will now be described in detail with reference to the accompanying drawings and embodiments.
[0023] Among related technologies, the main methods for separating flexible display devices from glass substrates include laser lift-off (LLO), mechanical lift-off (MLO), and chemical etching.
[0024] While laser peeling technology has advantages such as high precision and non-contact operation, the high cost of laser equipment, complex process debugging, and high maintenance requirements make it difficult to adapt to the needs of small-batch panel production in terms of economy and flexibility.
[0025] Mechanical peeling does not require expensive lasers and sophisticated optical systems, making it a simple and low-cost peeling solution. However, the adhesive or release layer it relies on faces challenges in material selection and preparation processes, such as difficulty in controlling the bonding strength and interface residue, which affect the peeling quality and yield.
[0026] Chemical etching typically requires a sacrificial layer to be placed between the glass substrate and the flexible substrate, which is then removed in subsequent processes. It is convenient to operate and applicable to a wide range of materials. However, the current chemical etching method for removing the sacrificial layer suffers from low etching efficiency of the etching solution, which to some extent restricts production efficiency.
[0027] Therefore, this application proposes a method for preparing a flexible display panel, the core of which lies in designing a sacrificial layer structure that can greatly accelerate the chemical etching process while simultaneously ensuring the flatness of the flexible substrate surface, thus solving the efficiency problem of existing chemical peeling technologies.
[0028] See Figures 1-9 , Figure 1 A schematic flowchart illustrating a method for fabricating a flexible display panel according to an embodiment of this application; Figure 2a for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S11 in one embodiment; Figure 2b for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S11 in another embodiment; Figure 2c for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S11 in another embodiment; Figure 3afor Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S12 in one embodiment; Figure 3b for Figure 1 A schematic diagram of the intermediate product obtained after step S12 in another embodiment; Figure 3c for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S12 in another embodiment; Figure 4 for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S12 in an embodiment from a first perspective; Figure 5 for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S12 in another embodiment from a first perspective; Figure 6a for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S12 in an embodiment, viewed from a second perspective. Figure 6b for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S12 in another embodiment from a second perspective; Figure 6c for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S12 in another embodiment, viewed from a second perspective. Figure 7 for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S12 in another embodiment from a second perspective; Figure 8a for Figure 1 A schematic diagram of the structure of an intermediate product obtained after step S13; Figure 8b for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S13 in another embodiment; Figure 8c for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S13 in another embodiment; Figure 8d for Figure 8c A schematic diagram of the structure after the first and second substrates are separated. Figure 9 for Figure 1 A schematic diagram of the structure of the intermediate product obtained after step S14.
[0029] It should be noted that the "first perspective" in the accompanying drawings of this application refers to the side view of the intermediate product, and the "second perspective" refers to the top view of the intermediate product. The above perspective names are only used to distinguish the viewing direction and do not constitute a limitation on this application.
[0030] For details, see Figure 1 The method for manufacturing a flexible display panel provided in this application includes the following steps: Step S11: Provide a rigid substrate 10.
[0031] See details Figure 2a and Figure 2b First, a rigid substrate 10 is obtained as a support base for the fabrication process. The material of the rigid substrate 10 is not limited. In this application, the material of the rigid substrate 10 includes, but is not limited to, glass substrate, metal substrate, semiconductor substrate, etc.
[0032] Step S12: Prepare a sacrificial layer 20 on one surface of the rigid substrate 10.
[0033] Among them, the sacrificial layer 20 has a channel 21.
[0034] Optionally, the material of the sacrificial layer 20 may include, but is not limited to, common metals such as Cu and Al.
[0035] Optionally, the sacrificial layer 20 may be formed by sputtering with PVD equipment, chemical vapor deposition, electroplating or electrochemical deposition, etc., and is not limited here.
[0036] Optionally, the thickness of the sacrificial layer 20 can be 0.5~20μm. For example, the thickness of the sacrificial layer 20 can be 0.5μm; or, the thickness of the sacrificial layer 20 can be 5μm; or, the thickness of the sacrificial layer 20 can be 10μm; or, the thickness of the sacrificial layer 20 can be 20μm, etc., and there is no limitation here.
[0037] Of course, the dimensions of the rigid substrate 10 and the sacrificial layer 20 can be selected as needed, and are not limited here.
[0038] Among them, combined Figure 3a and Figure 4 The step of preparing a sacrificial layer 20 on one surface of a rigid substrate 10 includes: A sacrificial layer 20 is prepared on one surface of a rigid substrate 10.
[0039] The sacrificial layer 20 is patterned to form channels 21 on the sacrificial layer 20.
[0040] Specifically, by setting channels 21 on the sacrificial layer 20 and removing the filling material 30 in the channels 21 before performing the chemical etching process on the sacrificial layer 20, the chemical etching substances can quickly penetrate into the interior of the sacrificial layer 20 through the channels 21 during the subsequent chemical etching process, thereby significantly improving the chemical etching efficiency of the sacrificial layer 20 and thus improving the production efficiency of the flexible display panel.
[0041] In addition, by setting the channel 21 on the sacrificial layer 20, there is no need to set an auxiliary film layer for constructing the etching channel, which reduces the deposition process steps of the relevant film layer and also reduces the number of interlayer interfaces.
[0042] In the embodiments of this application, see Figure 4The channel 21 can penetrate the sacrificial layer 20 along its thickness direction. Alternatively, see... Figure 5 The channel 21 may extend along the surface of the sacrificial layer 20 away from the surface of the rigid substrate 10 toward the surface of the rigid substrate 10 but does not penetrate the sacrificial layer 20.
[0043] The sacrificial layer 20 can be patterned to form the grooves 21 using traditional coating, exposure, and development processes. The patterning method is not limited here.
[0044] In an alternative embodiment, see Figure 6a The sacrificial layer 20 is patterned to form a plurality of first channels extending along the length direction of the sacrificial layer 20; wherein each first channel penetrates the sacrificial layer 20 along the thickness direction and the length direction of the sacrificial layer 20; the first channel serves as a channel 21 on the sacrificial layer 20.
[0045] In another alternative embodiment, see Figure 6b The sacrificial layer 20 is patterned to form a plurality of first channels extending along the length direction of the sacrificial layer 20; wherein each first channel penetrates the sacrificial layer 20 along the thickness direction but does not penetrate the sacrificial layer 20 along the length direction.
[0046] Optionally, see Figure 6c A plurality of first channels extending along the length direction of the sacrificial layer 20 are formed on the sacrificial layer 20, and at least two second channels extending along the width direction of the sacrificial layer 20 are formed to connect the plurality of first channels.
[0047] In another alternative embodiment, see Figure 7 The sacrificial layer 20 is patterned to form a plurality of second channels extending along the width direction of the sacrificial layer 20; wherein each second channel penetrates the sacrificial layer 20 along the thickness direction and the width direction; the second channel serves as a channel 21 on the sacrificial layer 20.
[0048] In another alternative embodiment, the sacrificial layer 20 is patterned to form a plurality of first channels extending along the length direction of the sacrificial layer 20 and a plurality of second channels extending along the width direction of the sacrificial layer 20; wherein the first channels penetrate the sacrificial layer 20 along the thickness direction and the length direction; the second channels penetrate the sacrificial layer 20 along the thickness direction and the width direction; and the first channels and the second channels intersect; the first channels and the second channels serve as channels 21 on the sacrificial layer 20; in this embodiment, the remaining sacrificial layers 20 are arranged in an array.
[0049] In this embodiment of the application, the ratio of the spacing between adjacent first channels to the width of the first channel along the width direction is 1:0.5-1:1.
[0050] And / or, the ratio of the spacing between adjacent second channels to the width of the second channel along its length is 1:0.5-1:1.
[0051] For example, the ratio of the spacing between adjacent first channels to the width of the first channel along the width direction is 1:1; another example is that the ratio of the spacing between adjacent first channels to the width of the first channel along the width direction is 1:0.75; yet another example is that the ratio of the spacing between adjacent first channels to the width of the first channel along the width direction is 1:0.5.
[0052] For example, the ratio of the spacing between adjacent second channels to the width of the second channel along the length direction is 1:1; another example is that the ratio of the spacing between adjacent second channels to the width of the second channel along the width direction is 1:0.75; yet another example is that the ratio of the spacing between adjacent second channels to the width of the second channel along the width direction is 1:0.5.
[0053] Specifically, by setting the ratio of the spacing between channels 21 to the width of channels 21 in the width direction to 1:0.5-1:1, it is possible to ensure that the channels 21 are distributed relatively evenly, so that the etching solution can etch the sacrificial layer 20 more evenly. On the other hand, it can also avoid the sacrificial layer 20 being too small due to the channels 21 being set too sparsely or too densely, which is conducive to balancing etching efficiency and the structural support role of the sacrificial layer 20 before separation.
[0054] It is understood that the above ratios are only some optional implementation methods and are not limited here. In actual applications, they can be adjusted according to device size, sacrificial layer thickness, material properties and etching process parameters.
[0055] In other embodiments, the channels 21 may also be arranged in a meandering manner, and the inner diameters of the channels 21 may be inconsistent or not consistent, which can be selected as needed and is not limited here.
[0056] In another embodiment of this application, see Figure 2b and Figure 3b The rigid substrate 10 has a trench 11 on one surface; the step of preparing a sacrificial layer 20 on one surface of the rigid substrate 10 includes: A sacrificial layer 20 is prepared on the surface of a rigid substrate 10 having a trench 11; wherein a portion of the sacrificial layer 20 is recessed within the trench 11, thereby forming a channel 21.
[0057] See details Figure 2b The depth of the trench 11 can be less than the thickness of the rigid substrate 10. For example, a surface of the rigid substrate 10 can be patterned to form the trench 11 on the rigid substrate 10.
[0058] See details Figure 3b By forming channels 21 by partially recessing the sacrificial layer 20 within the trench 11 during the deposition process, the step of patterning the sacrificial layer 20 can be omitted.
[0059] It is understood that by setting channels 21 on the sacrificial layer 20 and removing the filling material 30 in the channels 21 before performing the chemical etching process on the sacrificial layer 20, the chemical etching substances can quickly penetrate into the interior of the sacrificial layer 20 through the channels 21 during the subsequent chemical etching process, thereby significantly improving the chemical etching efficiency of the sacrificial layer 20 and thus improving the production efficiency of the flexible display panel.
[0060] Furthermore, by forming trenches 11 on the rigid substrate 10, the sacrificial layer 20 is partially recessed within the trenches 11 to form channels 21. This prevents the sacrificial layer 20 at both ends of the channel 21 from being etched away first during subsequent etching, which could cause the edges of the flexible substrate 50 to lose the support of the sacrificial layer 20 and adhere to the rigid substrate 10. This would make it difficult for the chemical etching material to flow from both ends of the channel 21 to the middle area, resulting in blocked or insufficient etching in the middle area. In addition, the waste liquid formed by the chemical etching material etching the sacrificial layer 20 can flow out along the trenches 11 and be recycled, avoiding operational difficulties caused by the waste liquid flowing freely between the flexible substrate 50 and the rigid substrate 10.
[0061] in, Figure 3b The channel 21 shown can be connected with Figure 4 The dimensions of the channels 21 are consistent and will not be described in detail here.
[0062] In another embodiment of this application, see Figure 2c and Figure 3c The rigid substrate 10 includes a first substrate 101 and a second substrate 102 stacked together; the first substrate 101 has a seamless structure, and the second substrate 102 has a plurality of through holes 103 spaced apart. The first substrate 101 blocks the through holes 103 to form a trench 11.
[0063] This application, by combining a first substrate 101 and a second substrate 102, allows the channel 21 to be formed without patterning the sacrificial layer 20, thus simplifying the fabrication process. Furthermore, the first substrate 101 and the second substrate 102 can be reused as molds, thereby reducing manufacturing costs.
[0064] The step of preparing a sacrificial layer 20 on one surface of a rigid substrate 10 includes: See Figure 8c A sacrificial layer 20 is prepared on the surface of the second substrate 102 away from the first substrate 101; wherein a portion of the sacrificial layer 20 is recessed in the trench 11, thereby forming a channel 21.
[0065] Step S13: Fill the channel 21 with filler material 30.
[0066] See Figure 8a , Figure 8b or Figure 8c The sacrificial layer 20 and the filler material 30 form a composite sacrificial layer 40.
[0067] Specifically, by filling the channel 21 with filler material 30, the depressions or steps formed in the channel 21 can be improved, thereby providing a relatively flat support interface for the subsequent formation of the flexible substrate 50. This avoids the flexible substrate 50 from sinking locally at the corresponding channel 21 position due to suspension or insufficient support, improves the thickness uniformity and surface flatness of the subsequently formed flexible substrate 50, and ensures its structural stability and device performance.
[0068] Optionally, the filler material 30 may include, but is not limited to, polyvinyl alcohol (PVA), polymethyl methacrylate (PMMA), epoxy resin, or photoresist.
[0069] In some embodiments, step S13 includes: Polyvinyl alcohol is filled in the channel 21, such that the surface of the polyvinyl alcohol away from the rigid substrate 10 is flush with the surface of the sacrificial layer 20 away from the rigid substrate 10.
[0070] Alternatively, polymethyl methacrylate (PMMA) can be filled into the channel 21, such that the surface of PMMA away from the rigid substrate 10 is flush with the surface of the sacrificial layer 20 away from the rigid substrate 10.
[0071] Specifically, by making the surface of the filling material 30 facing away from the rigid substrate 10 flush with the surface of the sacrificial layer 20 facing away from the rigid substrate 10, the depression or step formed by the channel 21 on the surface of the sacrificial layer 20 can be further reduced, thereby providing a flat support interface for the subsequent formation of the flexible substrate 50, improving the thickness uniformity and surface flatness of the subsequently formed flexible substrate 50, and ensuring its structural stability and device performance.
[0072] The filling method of the filler material 30 includes, but is not limited to, printing or coating processes, and is not limited here.
[0073] Step S14: Prepare a flexible substrate 50 on the surface of the composite sacrificial layer 40 that is away from the rigid substrate 10.
[0074] After the flexible substrate 50 is formed, at least part of the channel 21 remains open so that external medium can enter the channel 21 to prepare for the flow of chemical etching material into the sacrificial layer 20.
[0075] Optionally, see Figure 6a and Figure 7At least part of the channel 21 extends to the edge of the sacrificial layer 20, so that the flexible substrate 50 does not completely cover the channel 21, so that the channel 21 remains open.
[0076] Optional, see Figure 8d Since the sacrificial layer 20 on the surface of the first substrate 101 is bonded to the first substrate 101, when the first substrate 101 and the second substrate 102 are separated, the separated first substrate 101 will take away the sacrificial layer 20 on its surface, thereby exposing the channel 21 and the filling material 30 so that the channel 21 remains open.
[0077] Alternatively, in other embodiments, the flexible substrate 50 may not completely cover the channel 21 of the sacrificial layer 20, so that at least part of the channel 21 is exposed.
[0078] See details Figure 9 The flexible substrate 50 may be made of materials including, but not limited to, polyimide (PI), transparent polyimide (CPI), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN). This application example uses transparent polyimide as the material of the flexible substrate 50.
[0079] Optional, see Figure 10 , Figure 10 for Figure 1 A flowchart illustrating a specific embodiment of step S14, which includes: Step S141: Apply a polyimide solution to the surface of the composite sacrificial layer 40 facing away from the rigid substrate 10.
[0080] Step S142: Curing the polyimide solution to form the first preform of the flexible substrate 50.
[0081] Step S143: Imidize the first preform to form a flexible substrate 50.
[0082] In one specific embodiment, step S142 includes a first stage and a second stage, wherein the preparation temperature of the first stage is 80~120℃ and the holding time is 5~15min, which is used to remove most of the organic solvent; the preparation temperature of the second stage is 150~180℃ and the holding time is 20~40min, which is used to remove the remaining organic solvent.
[0083] Step S143 includes a third stage and a fourth stage. The preparation temperature of the third stage is 250~300℃ and the holding time is 20~40min, which is used to perform an imidization reaction on the first preform to form a polyimide structure. The preparation temperature of the fourth stage is 350~400℃ and the holding time is 30~60min, which is used to completely imidize the first preform to obtain a flexible substrate 50 and obtain the best heat resistance and mechanical properties.
[0084] See Figures 11-12 , Figure 11 A schematic flowchart illustrating a method for fabricating a flexible display panel according to another embodiment of this application; Figure 12 for Figure 11 A schematic diagram of the structure of the intermediate product obtained after step S21. In this embodiment of the application, the preparation method further includes: Step S21: Remove the filler material 30 within the composite sacrificial layer 40.
[0085] Specifically, after the flexible substrate 50 is prepared, or during the preparation of the flexible substrate 50, or after all the film layers of the flexible display panel are prepared, the filling material 30 in the composite sacrificial layer 40 can be removed so that the subsequent chemical etching substances can enter the channel 21 and etch the sacrificial layer 20.
[0086] Taking polyvinyl alcohol as an example, the filler material 30 may be removed from the composite sacrificial layer 40. Optionally, the step of removing the filler material 30 may include: Before imidizing the first preform, the composite sacrificial layer 40 is placed in water at a first preset temperature to dissolve the filler material 30.
[0087] For example, after the second stage, the composite sacrificial layer 40 is dissolved in warm water at 70~95°C, which can dissolve the filler material 30 and expose the patterned structure of the sacrificial layer 20.
[0088] Alternatively, during the imidization of the first preform, the filler material 30 is thermally decomposed.
[0089] For example, during the fourth stage of complete imidization of the first preform, the filler material 30 is simultaneously decomposed, exposing the patterned structure of the sacrificial layer 20. At this point, it is necessary to extend the holding time of the fourth stage, for example, to 90-120 minutes.
[0090] In another embodiment of this application, polymethyl methacrylate is used as an example for the filler material 30. Optionally, the step of removing the filler material 30 within the composite sacrificial layer 40 includes: During the imidization of the first preform, the filler material 30 is thermally decomposed.
[0091] For example, during the fourth stage of the complete imidization of the first preform, the filler material 30 is simultaneously thermally decomposed, exposing the patterned structure of the sacrificial layer 20.
[0092] Through the above treatment, the channel 21 on the sacrificial layer 20 can be re-exposed so that subsequent chemical etching substances can enter along the channel 21 and etch the sacrificial layer 20, thereby achieving the separation of the rigid substrate 10 and the flexible substrate 50.
[0093] See Figure 13 and Figure 14 , Figure 13 A schematic flowchart illustrating a method for fabricating a flexible display panel according to another embodiment of this application; Figure 14 for Figure 13 A schematic diagram of the structure of the intermediate product obtained after step S31. In one embodiment of this application, the method for preparing a flexible display panel further includes: Step S31: Prepare an encapsulation layer 60 on the surface of the flexible substrate 50 that is opposite to the rigid substrate 10.
[0094] See details Figure 14 The encapsulation layer 60 is used to fill the micro-nano-level pores and defects that may exist on the surface of the flexible substrate 50 after coating and curing, and to block moisture and prevent corrosion of the upper film layer, such as metal wires.
[0095] The encapsulation layer 60 can be a single film layer or a composite film layer, and the material of the encapsulation layer 60 includes, but is not limited to, silicon oxide, silicon nitride, aluminum oxide, silicon oxynitride, polyimide, epoxy resin, acrylic resin and combinations thereof, which are not limited here.
[0096] Optionally, step S31 includes: Step S311: A silicon nitride layer is prepared on the surface of the flexible substrate 50 opposite to the rigid substrate 10.
[0097] Step S312: Prepare a silicon oxide layer on the surface of the silicon nitride layer away from the rigid substrate 10.
[0098] Optionally, the silicon nitride layer (SiNx) and the silicon oxide layer (SiO2) can be prepared by PECVD process, and the thickness of the silicon nitride layer and the silicon oxide layer can be 1~10μm, respectively.
[0099] Specifically, this application adds an encapsulation layer 60 formed by a silicon nitride layer and a silicon oxide layer between the flexible substrate 50 and subsequent film layers (such as a display device layer). Both the silicon nitride layer and the silicon oxide layer have good density. The silicon nitride layer is beneficial for blocking moisture and impurities, while the silicon oxide layer is beneficial for further improving the interface protection effect and structural stability. Therefore, by combining the two to form the encapsulation layer 60, the adverse effects of the external environment on subsequent film layers can be effectively reduced, and the stability of subsequent film layers and the overall reliability of the device can be improved.
[0100] Further, see Figure 15 and Figure 16 , Figure 15 A schematic flowchart illustrating a method for fabricating a flexible display panel according to another embodiment of this application; Figure 16 for Figure 15A schematic diagram of the intermediate product obtained after step S41. In one embodiment of this application, the method for manufacturing a flexible display panel further includes: Step S41: The first composite substrate 100 and the second composite substrate 200 are assembled together to form a preform of a flexible display panel.
[0101] The first composite substrate 100 and the second composite substrate 200 are disposed opposite to each other, and a display layer 90 is disposed between them to form a preform of a flexible display panel.
[0102] The first composite substrate 100 and the second composite substrate 200 may each include a rigid substrate 10, a sacrificial layer 20 with a channel 21 and a flexible substrate 50. Furthermore, the first composite substrate 100 and the second composite substrate 200 may also include an encapsulation layer 60.
[0103] The first composite substrate 100 may further include a driving circuit layer 80; the second composite substrate 200 may further include a common electrode layer 70, etc., to meet the application requirements of the display device. By aligning the first composite substrate 100 and the second composite substrate 200 together and placing a display layer 90 between them, a preform of a flexible display panel is formed.
[0104] Optionally, a display layer 90 may be disposed between the first composite substrate 100 and the second composite substrate 200. For the sake of brevity, the accompanying drawings... Figure 16 The related structures located between the first composite substrate 100 and the second composite substrate 200 and used to realize the display function can be collectively referred to as the display layer 90.
[0105] In one embodiment, when the flexible display panel is a liquid crystal display panel, the display layer 90 may include a liquid crystal layer, and the first composite substrate 100 and the second composite substrate 200 are disposed opposite to each other to form a preform of the liquid crystal display panel. In another embodiment, when the flexible display panel is an OLED display panel, the display layer 90 may include a light-emitting layer. Optionally, the light-emitting layer may be disposed on one side of the first composite substrate 100 or on one side of the second composite substrate 200, and the specific choice can be made according to the needs of the device structure design, which is not limited here.
[0106] See Figure 17 and Figure 18 , Figure 17 A schematic flowchart illustrating the fabrication method of a flexible display panel provided in other embodiments of this application; Figure 18 for Figure 17 A schematic diagram of the structure of the intermediate product obtained after step S51. In one embodiment of this application, the method for manufacturing a flexible display panel provided by this application further includes: Step S51: Chemically etch the sacrificial layer 20 to separate the rigid substrate 10 from the flexible substrate 50.
[0107] Optionally, step S51 includes: The sacrificial layer 20 is placed in a chemical solution to etch the sacrificial layer 20, thereby separating the rigid substrate 10 from the flexible substrate 50.
[0108] Alternatively, the sacrificial layer 20 can be placed in a chemical atmosphere to etch the sacrificial layer 20, thereby separating the rigid substrate 10 from the flexible substrate 50.
[0109] After step S51, a flexible display panel is formed.
[0110] The sacrificial layer 20 has channels 21, and the etching medium can penetrate into the interior of the sacrificial layer 20 along the channels 21 and increase the contact area with the sacrificial layer 20, thereby improving the corrosion efficiency and shortening the separation time.
[0111] exist Figure 17 In the embodiment shown, step S51 can be performed after step S41 or before step S41. The specific execution sequence can be selected according to the product structure design, process integration method and production needs, and is not limited here.
[0112] It should be understood that the sequence of steps shown in the flowchart of this application is only illustrative and does not constitute a limitation on this application. Unless otherwise specified, the execution order of each step can be adjusted according to actual process requirements.
[0113] This application improves chemical etching efficiency by creating channels 21 on the sacrificial layer 20, allowing the etching solution to quickly penetrate into the interior of the sacrificial layer 20 in subsequent steps. By making the channels 21 flush with the surface of the filler material 30 away from the rigid substrate 10, the formation of depressions or steps on that surface by the channels 21 is avoided, providing a smoother support interface for the subsequent formation of the flexible substrate 50. Furthermore, by creating channels 21 on the sacrificial layer 20, this application eliminates the need for additional auxiliary films for constructing etching channels, reducing the number of deposition steps for related films and the number of interlayer interfaces. This application can also form channels 21 by creating trenches 11 on the rigid substrate 10, causing the sacrificial layer 20 to partially recess into the trenches 11. This prevents the flexible substrate 50 from losing the support of the sacrificial layer 20 and adhering to the rigid substrate 10 during subsequent etching, thus avoiding the blockage of the chemical etching material from continuing to etch.
[0114] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.
Claims
1. A method for manufacturing a flexible display panel, characterized in that, include: Provide rigid substrates; A sacrificial layer is prepared on one surface of the rigid substrate; wherein the sacrificial layer has channels; The channel is filled with a filler material; the sacrificial layer and the filler material form a composite sacrificial layer. A flexible substrate is fabricated on the surface of the composite sacrificial layer that is away from the rigid substrate; Wherein, after the flexible substrate is formed, at least a portion of the channels remain open to allow external media to enter the channels; The preparation method further includes: Remove the filler material within the composite sacrificial layer; The sacrificial layer is chemically etched to separate the rigid substrate from the flexible substrate.
2. The preparation method according to claim 1, characterized in that, The step of preparing a sacrificial layer on one surface of the rigid substrate includes: The sacrificial layer is prepared on one surface of the rigid substrate; The sacrificial layer is patterned to form the trench on the sacrificial layer.
3. The preparation method according to claim 2, characterized in that, The step of patterning the sacrificial layer includes: The sacrificial layer is patterned to form a plurality of first channels extending along the length direction of the sacrificial layer; wherein each first channel penetrates the sacrificial layer along both the thickness and length directions; the first channel serves as a channel on the sacrificial layer; or... The sacrificial layer is patterned to form a plurality of second channels extending along the width direction of the sacrificial layer; wherein each second channel penetrates the sacrificial layer along both the thickness and width directions; the second channel serves as a channel on the sacrificial layer; or... The sacrificial layer is patterned to form a plurality of first channels extending along the length direction of the sacrificial layer and a plurality of second channels extending along the width direction of the sacrificial layer; wherein the first channels penetrate the sacrificial layer along the thickness direction and the length direction; the second channels penetrate the sacrificial layer along the thickness direction and the width direction; and the first channels and the second channels intersect; the first channels and the second channels serve as channels on the sacrificial layer.
4. The preparation method according to claim 1, characterized in that, One surface of the rigid substrate has grooves; The step of preparing a sacrificial layer on one surface of the rigid substrate includes: The sacrificial layer is prepared on the surface of the rigid substrate having the trench; wherein a portion of the sacrificial layer is recessed within the trench, thereby forming the channel.
5. The preparation method according to claim 1, characterized in that, The step of filling the trench with filler material includes: The trench is filled with polyvinyl alcohol, such that the surface of the polyvinyl alcohol facing away from the rigid substrate is flush with the surface of the sacrificial layer facing away from the rigid substrate; or The channel is filled with polymethyl methacrylate, such that the surface of the polymethyl methacrylate facing away from the rigid substrate is flush with the surface of the sacrificial layer facing away from the rigid substrate.
6. The preparation method according to claim 5, characterized in that, The step of fabricating a flexible substrate on the surface of the composite sacrificial layer opposite to the rigid substrate includes: A polyimide solution is coated on the surface of the composite sacrificial layer that is away from the rigid substrate; The polyimide solution is cured to form a first preform of the flexible substrate; The first preform is imidized to form the flexible substrate; The filler material is polyvinyl alcohol; the step of removing the filler material from the composite sacrificial layer includes: Before imidizing the first preform, the composite sacrificial layer is placed in water at a first preset temperature to dissolve the filler material; or During the imidization of the first preform, the filler material undergoes thermal decomposition.
7. The preparation method according to claim 5, characterized in that, The step of fabricating a flexible substrate on the surface of the composite sacrificial layer opposite to the rigid substrate includes: A polyimide solution is coated on the surface of the composite sacrificial layer that is away from the rigid substrate; The polyimide solution is cured to form a first preform of the flexible substrate; The first preform is imidized to form the flexible substrate; The filler material is the polymethyl methacrylate; the step of removing the filler material from the composite sacrificial layer includes: During the imidization of the first preform, the filler material undergoes thermal decomposition.
8. The preparation method according to claim 1, characterized in that, The preparation method further includes: An encapsulation layer is prepared on the surface of the flexible substrate opposite to the rigid substrate.
9. The preparation method according to claim 8, characterized in that, The step of fabricating an encapsulation layer on the surface of the flexible substrate opposite to the rigid substrate includes: A silicon nitride layer is prepared on the surface of the flexible substrate opposite to the rigid substrate; A silicon oxide layer is prepared on the surface of the silicon nitride layer that is away from the rigid substrate.
10. The preparation method according to claim 1, characterized in that, The method further includes: A first composite substrate and a second composite substrate are assembled together to form a preform of the flexible display panel; wherein, both the first composite substrate and the second composite substrate include the rigid substrate, the sacrificial layer having the channel, and the flexible substrate; The step of chemically etching the sacrificial layer includes: The preform of the flexible display panel is placed in a chemical etching environment to chemically etch the sacrificial layer.
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