阅读说明：本技术 柔性显示面板及其制备方法 (Flexible display panel and preparation method thereof ) 是由 陈逸 于 2019-10-30 设计创作，主要内容包括：本申请公开了一种柔性显示面板及其制备方法，制备方法包括：提供一柔性基板，柔性基板至少包括柔性弯折区；在柔性基板上形成无机膜层；对无机膜层上和柔性弯折区对应区域的进行一次刻蚀，以形成具有坡度的深孔；向深孔中填充有机材料以形成有机膜层；在有机膜层和无机膜层上形成金属走线层。通过上述方式，本申请能够缩短制程的流程，降低生产成本，提高产线的生产效率。(The application discloses a flexible display panel and a preparation method thereof, wherein the preparation method comprises the following steps: providing a flexible substrate, wherein the flexible substrate at least comprises a flexible bending area; forming an inorganic film layer on a flexible substrate; etching the areas corresponding to the flexible bending areas on the inorganic film layer for the first time to form a deep hole with gradient; filling organic materials into the deep hole to form an organic film layer; and forming a metal wiring layer on the organic film layer and the inorganic film layer. Through the mode, the process of the manufacturing procedure can be shortened, the production cost is reduced, and the production efficiency of a production line is improved.)

1. A method for manufacturing a flexible display panel, the method comprising:

providing a flexible substrate, wherein the flexible substrate at least comprises a flexible bending area;

forming an inorganic film layer on the flexible substrate;

etching the inorganic film layer and the area corresponding to the flexible bending area for the first time to form a deep hole with gradient;

filling organic materials into the deep hole to form an organic film layer;

and forming a metal wiring layer on the organic film layer and the inorganic film layer.

2. The preparation method according to claim 1, wherein the performing of the primary etching on the inorganic film layer and the region corresponding to the flexible bending region to form the deep hole with the slope comprises:

coating a photoresist layer on the inorganic film layer;

patterning the photoresist layer to expose at least the flexible bending region corresponding to the organic film layer;

and etching the flexible bending area for one time to form the deep hole with gradient.

3. The method of claim 2, wherein the photoresist layer has a thickness greater than or equal to 2.5 um.

4. The manufacturing method according to claim 2, wherein the time for performing the primary etching on the flexible bending region is in a range of 450s-600 s.

5. The preparation method according to claim 2, wherein the flexible bending region is etched by dry etching.

6. The method of claim 2, wherein the patterning the photoresist layer to expose at least the flexible bending region corresponding to the organic film layer comprises:

aligning the photoresist layer by using a photoetching template with a preset pattern;

transferring the preset pattern onto the photoresist layer by exposure;

copying the preset pattern onto the photoresist layer through development so as to expose at least the flexible bending area corresponding to the organic film layer.

7. The method according to claim 1, wherein the forming an inorganic film layer on the flexible substrate comprises:

and sequentially depositing and patterning an isolation layer, a buffer layer, an active layer, a first gate insulating layer, a gate layer and a second gate insulating layer on the flexible substrate.

8. The method of manufacturing according to claim 1, further comprising:

and sequentially forming a flat layer, an anode layer, a pixel layer and a supporting layer on the metal wiring layer to manufacture the flexible display panel.

9. The manufacturing method according to any one of claims 1 to 8, wherein the metal routing layer on the organic film layer comprises a hollowed-out metal routing design.

10. A flexible display panel is characterized by comprising a flexible substrate, wherein the flexible substrate at least comprises a flexible bending area, an inorganic film layer, an organic film layer and a metal wiring layer, wherein the inorganic film layer and the organic film layer are sequentially arranged on the flexible substrate;

wherein, the inorganic film layer has a deep hole corresponding to the flexible bending region, the organic film layer is at least filled in the deep hole, and the preparation methods of the organic film layer, the deep hole and the inorganic film layer are as set in any one of claims 1 to 9.

Technical Field

The application relates to the technical field of display, in particular to a flexible display panel and a preparation method thereof.

Background

Organic Light-Emitting diodes (OLEDs) are increasingly used in a wide range of applications due to their advantages of Light weight, self-luminescence, wide viewing angle, low driving voltage, high Light-Emitting efficiency, low power consumption, fast response speed, and the like. Especially, a Flexible organic light emitting diode (Flexible OLED) display device is a main field of research and development in the field of display technology because of its characteristics of being bendable and easy to carry.

The number of the photoetching templates (masks) is very important in the fabrication of the driving back plate of the OLED, more than 12 photoetching templates are generally needed for realizing the flexible display panel, and 14-15 photoetching templates are needed for realizing a high-resolution product.

At present, the flexible OLED and the non-flexible OLED are different in that a deep hole region (deep hole) is required in the flexible OLED, but in the prior art, 2 photolithography templates are required to be used when the deep hole region is formed, and the process is complex and the cost is high.

Disclosure of Invention

The application provides a flexible display panel and a preparation method thereof, which can solve the problems of complex manufacturing process and high cost when a deep hole region of the flexible display panel is formed in the prior art.

In order to solve the technical problem, the application adopts a technical scheme that: provided is a method of manufacturing a flexible display panel, the method including: providing a flexible substrate, wherein the flexible substrate at least comprises a flexible bending area; forming an inorganic film layer on the flexible substrate; etching the inorganic film layer and the area corresponding to the flexible bending area for the first time to form a deep hole with gradient; filling organic materials into the deep hole to form an organic film layer; and forming a metal wiring layer on the organic film layer and the inorganic film layer.

Wherein, the etching of the inorganic film layer and the corresponding region of the flexible bending region for one time to form a deep hole with a slope comprises: coating a photoresist layer on the inorganic film layer; patterning the photoresist layer to expose at least the flexible bending region corresponding to the organic film layer; and etching the flexible bending area to form the deep hole with gradient.

Wherein the thickness of the photoresist layer is greater than or equal to 2.5 um.

Wherein, the time range of the primary etching of the flexible bending area is 450s-600 s.

And etching the flexible bending area by adopting a dry etching method.

Wherein the patterning the photoresist layer to expose at least the flexible bending region corresponding to the organic film layer comprises: aligning the photoresist layer by using a photoetching template with a preset pattern; transferring the preset pattern onto the photoresist layer by exposure; copying the preset pattern onto the photoresist layer through development so as to expose at least the flexible bending area corresponding to the organic film layer.

Wherein the forming an inorganic film layer on the flexible substrate includes: and sequentially depositing and patterning the flexible substrate to form an interlayer, a buffer layer, an active layer, a first grid insulating layer, a grid layer, a second grid insulating layer and a drain layer.

Wherein, the preparation method further comprises the following steps: and sequentially forming a flat layer, an anode layer, a pixel layer and a supporting layer on the metal wiring layer to manufacture the flexible display panel.

The metal wiring layer on the organic film layer comprises a hollow metal wiring design.

In order to solve the above technical problem, another technical solution adopted by the present application is: the flexible display panel comprises a flexible substrate, wherein the flexible substrate at least comprises a flexible bending area, an inorganic film layer, an organic film layer and a metal wiring layer, wherein the inorganic film layer and the organic film layer are sequentially arranged on the flexible substrate; the inorganic film layer is provided with a deep hole corresponding to the flexible bending area, the organic film layer is at least filled in the deep hole, and the preparation methods of the organic film layer, the deep hole and the inorganic film layer are any one of the preparation methods.

The beneficial effect of this application is: different from the situation of the prior art, the application provides the flexible display panel and the preparation method thereof, the deep hole of the flexible display panel is formed through one-step etching, the process flow can be shortened, the production cost is reduced, and the production efficiency of a production line is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

FIG. 1 is a schematic flow chart diagram illustrating an embodiment of a method for manufacturing a flexible display panel according to the present disclosure;

FIG. 2 is a schematic view of the preparation of one embodiment of the inorganic film layer of the present application;

FIG. 3 is a schematic view of one embodiment of a one-step process for preparing a deep hole region according to the present application;

FIG. 4 is a schematic flow chart diagram illustrating an embodiment of step S320;

FIG. 5 is a schematic illustration of the preparation of one embodiment of the deep hole region of the present application;

FIG. 6 is a schematic view of the fabrication of an embodiment of the organic film layer of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that if directional indications (such as up, down, left, right, front, and back … …) are referred to in the embodiments of the present application, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present application, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present application.

Referring to fig. 1, fig. 1 is a schematic flow chart of an embodiment of a method for manufacturing a flexible display panel, as shown in fig. 1, the method for manufacturing a flexible display panel includes the following steps:

step S100: a flexible substrate is provided, wherein the flexible substrate at least comprises a flexible bending area.

With further reference to fig. 2, fig. 2 is a schematic view illustrating the preparation of an organic film according to an embodiment of the present invention, such as providing a flexible substrate 110 shown in fig. 2. In general, the material of the flexible substrate 110 may be polymer material such as polyimide plastic, polyetheretherketone, or transparent conductive polyester. In this embodiment, a Polyimide (PI) material is used, which has the characteristics of high temperature resistance, wide application temperature range, no obvious melting point, high insulating property, stable dielectric constant, and the like, and thus is widely used in a flexible substrate. The flexible substrate 110 at least includes a flexible bending region a, the flexible bending region a is used for bending or folding in the flexible display panel, and the flexible bending region a is usually configured as an inorganic film layer that does not include an active layer and various metal layers in the flexible display panel.

Step S200: an inorganic film layer is formed on a flexible substrate.

Optionally, the inorganic film layer may further include a barrier layer 120, a buffer layer 130, an active layer 140, a first gate insulating layer 150, a gate layer, and a second gate insulating layer 160.

In step S200, the barrier layer (barrier) 120, the buffer layer (buffer layer)130, the active layer (active layer)140, the first gate insulating layer (gate insulating layer1)150, the gate layer (gate layer)170, and the second gate insulating layer (GI2)160 are sequentially deposited and patterned on the flexible substrate 110.

Alternatively, the barrier layer 120 and the buffer layer 130 are formed on the flexible substrate 110, and a vapor deposition technique is generally used. Vapor deposition techniques utilize physical and chemical processes that occur in the vapor phase to form functional or decorative metallic, non-metallic, or compound coatings on the surface of a workpiece. The vapor deposition technology can be classified into three categories, i.e., chemical vapor deposition, physical vapor deposition, and plasma vapor deposition, according to the film forming mechanism.

Specifically, the barrier layer 120 may be formed of a nano silicon oxide (SiOx) for blocking moisture and air. In a specific embodiment, the thickness of the barrier layer 120 may be 5000 meters. Further, a buffer layer 130 is deposited on the barrier layer 120 by using a chemical vapor deposition technique, wherein the buffer layer 130 may be a mixture of nano silicon-based oxide and nano silicon-based nitride (SiNx), a thickness of the buffer layer 130 may be 3500 meters, and formation of the barrier layer 120 and the buffer layer 130 provides conditions for subsequent fabrication of amorphous silicon. In this embodiment, the barrier layer 120 and the buffer layer 130 can be generally manufactured in the same chamber, wherein the thicknesses of the barrier layer 120 and the buffer layer 130 are only an example and are not limited, and the thicknesses of the other layers are also examples for visual understanding and are not limited in this application.

Alternatively, an amorphous silicon layer is deposited on the buffer layer 130, and then crystallization exposure is performed, thereby etching to form the active layer 140, i.e., the Poly-Si layer. Optionally, a gate insulating layer and a gate layer are further deposited on the active layer 140. The gate insulating layer includes a first gate insulating layer 150(GI1) and a second gate insulating layer 160(GI2), and correspondingly, the gate layer includes a first gate layer 170 and a second gate layer 180. The first gate insulating layer 150 and the second gate insulating layer 160 may be made of SiOx or SiNx, and the first gate layer 170 and the second gate layer 180 may be made of one of chromium, gold, nickel, tungsten, titanium, or titanium nitride, or any combination thereof.

An interlayer insulating layer 190, i.e., an interlayer insulating layer 190(ILD layer) grown on the second gate layer 180 is further formed on the gate layer, thereby fabricating an inorganic film layer. The specific preparation method and process of the film layer can refer to the prior art, and the application is not limited herein.

S300, etching the inorganic film layer and the area corresponding to the flexible bending area for the first time to form a deep hole with gradient.

Referring to fig. 3, fig. 3 is a schematic flow chart of an embodiment of step S300 of the present application, and step S300 of fig. 3 further includes the following sub-steps:

and S310, coating a photoresist layer on the inorganic film layer.

In this application, in order to ensure that the photoresist can be well adhered to the surface of the inorganic film layer of the flexible substrate 110, so as to form a smooth film layer with good adhesion, the flexible substrate 110 must be pretreated, including cleaning, baking, and adhesion-promoting treatments, to keep the surface of the inorganic film layer of the flexible substrate 110 dry and clean.

Alternatively, photoresists can be classified into both negative and positive photoresists according to their chemical reaction mechanism and development principle. The insoluble matter formed after illumination is negative glue; on the contrary, the positive glue is insoluble in some solvents and becomes a soluble substance after being irradiated by light. By utilizing the performance, the photoresist is used as a coating, and a required circuit pattern can be etched on the surface of the silicon wafer.

The photoresist coated in the present application may be a negative photoresist or a positive photoresist, which is not specifically limited herein, and the coating manner may be spin coating, so that the thickness thereof is uniform. And in a specific embodiment, the thickness of the photoresist layer 300 coated on the inorganic film layer (interlayer insulating layer 190) in the present application ranges from 2.5um or more, and the thickness of the photoresist layer 300 in the present application ranges from 2.5 um. After the photoresist layer 300 is coated, it may be baked at a higher temperature to enhance the adhesion of the photoresist layer 300 and the inorganic film layer.

Compared with the scheme of forming the deep hole by etching for 2 times in the prior art, the method increases the thickness of the photoresist layer 300 to be more than or equal to 2.5um, and can improve the problem that more etching can not be performed due to insufficient thickness of the photoresist layer 300 in the prior art.

And S320, patterning the photoresist layer to at least expose the flexible bending area corresponding to the organic film layer.

Referring to fig. 4, fig. 4 is a schematic flow chart of an embodiment of step S320 of the present application, and step S320 of fig. 4 further includes the following sub-steps:

and S321, aligning the photoresist layer by using a photoetching template with a preset pattern.

Referring to fig. 5, fig. 5 is a schematic diagram of the preparation of an embodiment of the deep hole region of the present application, and referring to fig. 5, a photolithographic template 400 with a preset pattern is precisely aligned with a substrate after baking.

And S322, transferring the preset pattern to the photoresist layer through exposure.

The exposure time of step S322 is determined by the light source intensity, the type and thickness of the photoresist, and is not limited herein. The predetermined pattern on the lithography template 400 may be transferred onto the photoresist layer 300 by exposure.

And S323, copying a preset pattern onto the photoresist layer through development so as to expose at least the flexible bending area corresponding to the organic film layer.

As shown in fig. 5, a developing solution is sprayed on the exposed photoresist layer 300 or is soaked in the developing solution, wherein the positive photoresist is formed by melting the photoresist in the exposed area into the developing solution, whereas the negative photoresist is formed by melting the photoresist in the exposed area into the developing solution, and the latent image in the photoresist film is displayed, thereby forming a three-dimensional pattern corresponding to the predetermined pattern. As shown in fig. 5, the photoresist in the flexible bending region a corresponding to the organic film layer is melted into the developing solution, so that the photoresist layer 300 is not present in the region, and the patterning of the photoresist layer 300 is completed.

Of course, after the development is completed, a process line development inspection may be performed, and the development effect may be observed under a microscope, for example, whether the development is complete, whether the photoresist pattern is intact, and the like, which is not limited herein.

S330, etching the flexible bending area for one time to form a deep hole with gradient.

Further, dry etching is adopted to etch the flexible bending region A, and particularly SF can be adopted₆Gas etching all the inorganic film layer to form a layer with a slopeThe deep hole D of degree, and the bottom of deep hole D is located flexible substrate 110, and wherein dry etching has anisotropy and selectivity good, can etch out the deep hole D that the slope is gentler. Optionally, in the present application, the range of the angle a between the slope of the deep hole D and the flexible substrate 110 may be 95 ° to 135 °, specifically, 95 °, 115 °, 135 °, and the like, which is not specifically limited herein. It can be understood that, adopt the etching to form the deep hole D that has the slope in this application, can improve the climbing ability that the metal was walked the line, reduce or avoided the metal to walk the phenomenon that the broken string leads to display panel's signal of telecommunication to lose, promote display panel's quality.

Optionally, the time range of the primary etching adopted in the present application is controlled to be 450s-600s, specifically 450s, 524s, 600s, and the like. In this embodiment, the time for one etching is set to 450s, and the inorganic film layer at the deep hole D can be completely etched.

And after etching, removing the photoresist layer serving as the etching barrier layer, and finally forming the deep hole D without the step difference by adopting wet photoresist removal or dry photoresist removal.

Compared with the prior art that the deep hole D is formed by adopting two-step etching, the technical scheme of the application can reduce one photoetching template, shorten the process flow, reduce the production cost and improve the production efficiency of a production line.

And S400, filling organic materials into the deep holes to form an organic film layer.

Referring to fig. 6, fig. 6 is a schematic view illustrating a preparation process of an organic film according to an embodiment of the present invention, and referring to fig. 6, an organic material is filled into the deep hole D to form an organic film 200. Specifically, the organic material is uniformly coated on the interlayer insulating layer 190 and the deep hole D, and the organic material in the region except for the deep hole D is removed by exposure and development, so that only the organic material filling layer in the deep hole D region, i.e. the organic film layer 200, is left.

And S500, forming a metal routing layer on the organic film layer and the inorganic film layer.

Further, before forming the metal wiring layer, patterning is performed on the interlayer insulating layer 190, and a metal wiring layer 210 is formed on the patterned interlayer insulating layer 190, wherein the metal wiring layer 210 further includes a source/drain layer. Specifically, a metal wiring layer 210, i.e., an SD metal layer, may be grown on the interlayer insulating layer 190 by magnetron sputtering, and then exposed and etched to form a source/drain (not shown) and a metal signal wiring layer (not shown), and the metal wiring layer is connected to the metal wiring layer on the deep hole region side through the contact hole, so as to achieve smooth electrical signals.

In this embodiment, the metal routing layer 210 on the organic film layer includes a hollow metal routing design, and the hollow shape includes but is not limited to a diamond shape, a circular shape, a polygonal shape, and the like, so that the metal routing on the organic film layer can easily release stress, and the reliability of the metal routing can be improved.

Further, a planarization layer 220, an anode layer 230, a pixel layer 240, a support layer 250, etc. may be sequentially formed on the metal routing layer 210, thereby completing the manufacturing process of the entire flexible panel. The method and process for preparing the planarization layer 220, the anode layer 230, the pixel layer 240, and the support layer 250 may refer to a method and a process for preparing a display panel in the prior art, which is not limited herein.

In the above embodiment, the deep hole of the flexible display panel is formed by one-step etching, so that the process flow can be shortened, the production cost can be reduced, and the production efficiency of a production line can be improved.

The present application further provides a flexible display panel 100 in this application, and the flexible display panel includes flexible substrate, and flexible substrate includes flexible bending area at least, sets gradually inorganic rete, organic rete on flexible substrate and sets up the metal routing layer on inorganic rete and organic rete.

The organic film layer, the deep hole and the preparation method of the inorganic film layer can refer to the specific description of the above embodiments, and are not described herein again.

In summary, it is easily understood by those skilled in the art that the present application provides a flexible display panel and a method for manufacturing the same, which can shorten the process flow, reduce the production cost, and improve the production efficiency of the production line by etching the deep hole of the flexible display panel by a one-step method.

The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application or are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.