WO2019100295A1

WO2019100295A1 - Fan-out structure of display panel, and preparation method and application thereof

Info

Publication number: WO2019100295A1
Application number: PCT/CN2017/112692
Authority: WO
Inventors: 江泽宁; 谭小平
Original assignee: 深圳市柔宇科技有限公司
Priority date: 2017-11-23
Filing date: 2017-11-23
Publication date: 2019-05-31
Also published as: CN111201486A

Abstract

A fan-out structure of a display panel, and a preparation method and application thereof. The fan-out structure of the display panel comprises: a flexible substrate (10); a barrier layer (20), provided on the upper surface of the flexible substrate (10); a fan-out wire layer (30), provided on the upper surface of the barrier layer (20); and a protective layer (40), provided on the upper surface of the fan-out wire. A stress central axis (1) of the fan-out structure is positioned on the barrier layer (20) or the fan-out wire layer (30). Therefore, the stress central axis (1) of the fan-out structure can be positioned on the barrier layer (20) or the fan-out wire layer (30) which is easily damaged during bending. Therefore, during bending, the barrier layer (20) or the fan-out wire layer (30) is not stressed by tension or compression, and is not easy to damage. That is, the damage of the fan-out structure is reduced, and the reliability of the fan-out structure is further improved.

Description

Fan-out structure of display panel and preparation method and application thereof

Technical field

The present invention relates to the field of display technology, and in particular, to a fan-out structure of a display panel, a preparation method thereof and an application thereof.

Background technique

At present, flexible display devices are getting more and more attention and welcome, but when the flexible display panel is bent, some structures and components, such as thin film transistors (TFTs), organic electroluminescent devices (OLEDs), and metal traces are easily bent. Folded and damaged.

Therefore, flexible display panels are for further study.

Summary of the invention

The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, an object of the present invention is to provide a fan-out structure of a display panel having advantages such as resistance to bending, electromagnetic interference, or electrostatic protection.

The present invention has been completed based on the discovery and knowledge of the inventors:

Since the barrier layer and the fan-out wire layer of the fan-out structure of the flexible display panel are particularly susceptible to damage when bent, the reliability of the fan-out structure is lowered. In view of the above problems, the inventors have found that there is a stress center axis in the fan-out structure, and the structure or component on the stress center axis is not subjected to tensile and compressive stress during bending, and will not be damaged due to the stress center axis. The position of the different layers of material and thickness are related, so the inventors according to the different layers of the fan-out structure and its thickness, such as adjusting the thickness of the protective layer or setting a buffer layer and adjusting its thickness, so that the fan-out structure of the stress Axis is located The barrier layer or the fan-out wire layer, when the barrier layer or the fan-out wire layer is bent, is not subjected to tensile and compressive stress, thereby reducing damage and improving the reliability of the fan-out structure.

In one aspect of the invention, the invention provides a fan-out structure for a display panel. According to an embodiment of the present invention, the fan-out structure of the display panel includes: a flexible substrate; a barrier layer, the barrier layer is disposed on an upper surface of the flexible substrate; a fan-out wire layer; and the fan-out wire layer is disposed on a protective layer disposed on an upper surface of the fan-out wire; wherein a stress center axis of the fan-out structure is located in the barrier layer or the fan-out wire On the floor. Therefore, the stress center axis of the fan-out structure can be located on the barrier layer or the fan-out wire layer which is easily damaged when bent, so that the barrier layer or the fan-out wire layer is not subjected to tensile and compressive stress when bent, and is not easily affected. Damage, that is, the damage of the fan-out structure is reduced, and the reliability of the fan-out structure is further improved.

According to an embodiment of the invention, the fan-out structure of the display panel further includes: a buffer layer disposed on an upper surface of the protective layer.

According to an embodiment of the invention, the buffer layer is a flexible conductive film.

According to an embodiment of the invention, the flexible conductive film is electrically connected to the fan-out wire layer.

According to an embodiment of the present invention, the material of the flexible conductive film is a PET-ITO conductive film or a graphene-metal nanowire-PET composite conductive film.

According to an embodiment of the invention, the flexible conductive film is provided with an opening.

In another aspect of the invention, the present invention provides a flexible display panel. According to an embodiment of the present invention, the flexible display panel includes the fan-out structure of the display panel described above. Thereby, the flexible display panel has high reliability and long service life.

In still another aspect of the present invention, the present invention provides a flexible display device. According to an embodiment of the invention, the flexible display device comprises the flexible display panel described above. Thereby, the flexible display device has high reliability and long service life.

In still another aspect of the present invention, the present invention provides a method of preparing the fan-out structure of the display panel described above. According to an embodiment of the present invention, the method includes: providing a flexible substrate; forming a barrier layer, the barrier layer is disposed on an upper surface of the flexible substrate; forming a fan-out wire layer, wherein the fan-out wire layer is disposed on the a protective layer disposed on an upper surface of the fan-out wire; wherein a stress center axis of the fan-out structure is located in the barrier layer or the fan-out wire layer on. Therefore, the preparation method is simple and quick, easy to operate, mature in process, easy to industrialize, and when the fan-out structure is prepared, the stress center axis of the fan-out structure is located at the barrier layer or the fan-out wire layer which is easily damaged when bent. Therefore, when the bending, the barrier layer or the fan-out wire layer is not subjected to tensile and compressive stress, and is not easily damaged, that is, the damage of the fan-out structure is reduced, and the reliability of the fan-out structure is further improved.

According to an embodiment of the present invention, the above method further includes the step of forming a buffer layer disposed on an upper surface of the protective layer.

According to an embodiment of the present invention, the above method further includes the step of electrically connecting the flexible conductive film to the fan-out wire layer.

DRAWINGS

1 is a schematic view showing the structure of a fan-out structure of a display panel in one embodiment of the present invention.

Fig. 2 is a view showing a model for calculating the position of the center axis of stress in another embodiment of the present invention.

Fig. 3 is a view showing the structure of a fan-out structure of a display panel in still another embodiment of the present invention.

Fig. 4 is a view showing the structure of a fan-out structure of a display panel in still another embodiment of the present invention.

Fig. 5 is a view showing the structure of a flexible display panel in still another embodiment of the present invention.

Fig. 6 is a flow chart showing the fan-out structure of a display panel in still another embodiment of the present invention.

7 is a flow chart showing the fan-out structure for preparing a display panel in still another embodiment of the present invention. Figure.

Fig. 8 is a flow chart showing the fan-out structure of a display panel in still another embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below. The embodiments described below are illustrative only and are not to be construed as limiting the invention. Where specific techniques or conditions are not indicated in the examples, they are carried out according to the techniques or conditions described in the literature in the art or in accordance with the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are conventional products that can be obtained commercially.

In one aspect of the invention, the invention provides a fan-out structure for a display panel. According to an embodiment of the present invention, referring to FIG. 1, the fan-out structure of the display panel includes: a flexible substrate 10; a barrier layer 20, the barrier layer 20 is disposed on the upper surface of the flexible substrate 10; the fan-out wire layer 30; the fan-out wire The layer 30 is disposed on the upper surface of the barrier layer 20; the protective layer 40 is disposed on the upper surface of the fan-out wire 30; wherein the stress center axis 1 of the fan-out structure (only the stress center axis is shown in the figure) The condition of the fan-out wire layer is located on the barrier layer 20 or the fan-out wire layer 30. Therefore, by adjusting the thickness of the protective layer, the stress center axis of the fan-out structure can be located on the barrier layer or the fan-out wire layer which is easily damaged when bent, so that the barrier layer or the fan-out wire layer is not bent when bent. The tensile and compressive stress is not easily damaged, that is, the damage of the fan-out structure is reduced, and the reliability of the fan-out structure is further improved.

It should be noted that the “upper surface” referred to in this document refers to the surface close to the user when the user uses it. The fan-out structure refers to the structure between the driving IC area and the display area.

As used herein, the term "stress central axis" refers to the stress neutral axis, which is the boundary between the tensile zone and the compression zone, and is not subject to tensile and compressive stress. In the display panel, the stress is generated when the flexible panel is bent. The position of the stress center axis is related to the material's Young's modulus and material thickness, and the surface where the stress center axis is located is the neutral plane, and the upper and lower area moments of the neutral plane are equal. From this, the distance from the neutral plane to the material boundary can be calculated. Taking a laminated structure with n layers as an example, i represents an ith layer structure, the Young's modulus is E _i , and the height of the section is h _i , if the stress center axis is at the ith layer, and the distance from the stress center axis to the bottom of the structure For X, its calculation formula is:

E ₁ ×L×h ₁ ×[h ₁ ÷2+h ₂ +h ₃ +...+h _i-1 +(h _i +h _i+1 +...+h _n -X)]+E ₂ ×L× h ₂

×[h ₂ ÷2+h ₃ +h ₄ +...+h _i-1 +(h _i +h _i+1 +...+h _n -X)]+...+E _i-1 ×L×h _{i- 1}

×[h _i-1 ÷2+(h _i +h _i+1 +...+h _n -X)]+E _i ×L×(h _i +h _i+1 +...+h _n -X)

×(h _i +h _i+1 +...+h _n -X)÷2

=E _i ×L×[X-(h _i+1 +h _i+2 +...+h _n )]×[X-(h _i+1 +h _i+2 +...+h _n )]÷2+ E _i+1 ×L

×h _i+1 ×[h _i+1 ÷2+(X-(h _i+1 +h _i+2 +...+h _n ))]+E _i+2 ×L×h _i+2

×[h _i+2 ÷2+h _i+1 +X-(h _i+1 +h _i+2 +...+h _n )]+E _i+3 ×L×h _i+3

×[h _i+3 ÷2+h _i+2 +h _i+1 +X-(h _i+1 +h _i+2 +...+h _n )]+...+E _n-1 ×L×h _{n -1}

×[h _n-1 ÷2+h _n-2 +...+h _i+1 +X-(h _i+1 +h _i+2 +...+h _n )]+E _n ×L×h _n

×[h _n ÷2+h _n-1 +...+h _i+1 +X-(h _i+1 +h _i+2 +...+h _n )]

From the above formula, the value of X can be calculated, that is, the position of the central axis of the stress is determined. The following is an example of a four-layer structure formed of four materials, and the calculation method of the stress center axis is described in detail: Referring to FIG. 2, the structure length is L, the Young's modulus of the material A is E _A , and the height of the section is h _A , the material The Young's modulus of _B is E _B , the height of the section is h _B , the Young's modulus of material C is E _C , the height of the section is h _C , the Young's modulus of material D is E _D , the height is h _D , the stress The distance from the central axis to the bottom of the structure is X, and the formula is:

E _A *L*h _A *(h _A /2+h _B +h _C +h _D -X)+E _B *L*(h _B +h _C +h _D -X) ² /2=E _B * L*(Xh _C -h _D ) ² /2+E _C *L*h _C *(Xh _C /2-h _D )+E _D *L*h _D *(Xh _D /2)

According to the embodiment of the present invention, the material for forming the flexible substrate is not particularly limited, and those skilled in the art can flexibly select according to actual needs. In some embodiments of the invention, materials forming the flexible substrate include, but are not limited to, polyimide or polyetheretherketone. Thereby, the material has better bending performance and good use performance.

According to an embodiment of the present invention, the material forming the barrier layer is not particularly limited, and those skilled in the art Can be flexibly selected according to actual needs. In some embodiments of the present invention, the material forming the barrier layer includes, but is not limited to, an organic insulating material such as silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride or polyimide, acryl. Therefore, the use performance is good.

According to the embodiment of the present invention, the material for forming the fan-out wire layer is also not limited, and those skilled in the art can flexibly select according to actual needs. In some embodiments of the invention, the material forming the fan-out wire layer includes, but is not limited to, chromium (Cr), molybdenum (Mo), titanium (Ti) / aluminum (Al) / titanium (Ti) alloy, aluminum (Al) /Molybdenum (Mo) alloy or other conductive material. Thereby, the conductivity is good and the use reliability is high.

According to the embodiment of the present invention, the material for forming the protective layer is not particularly limited, and those skilled in the art can flexibly select according to actual needs. In some embodiments of the present invention, the material forming the protective layer includes, but is not limited to, an organic insulating material such as silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride or polyimide, acryl. Therefore, the use performance is good.

According to an embodiment of the present invention, referring to FIG. 3, the fan-out structure of the display panel further includes a buffer layer 50 disposed on the upper surface of the protective layer 40. Therefore, by adjusting the thickness of the buffer layer, the stress center axis 1 of the fan-out structure is located on the barrier layer or the fan-out wire layer which is easily damaged when bent, so that the barrier layer or the fan-out wire layer is not bent when bent. The tensile and compressive stress is not easily damaged, that is, the damage of the fan-out structure is reduced, and the reliability of the fan-out structure is further improved.

According to the embodiment of the present invention, the material for forming the buffer layer is not particularly limited, and those skilled in the art can flexibly select according to actual needs. In some embodiments of the present invention, the material for forming the buffer layer includes, but is not limited to, inorganic materials such as silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride, or the like, or flexibility such as polyimide and polyether ether ketone. The material, or a flexible conductive film, such as a PET-ITO conductive film or a graphene-metal nanowire-PET composite conductive film. Therefore, the use performance is good.

It should be noted that the PET-ITO conductive film refers to sputtering or depositing a transparent indium tin oxide (ITO) conductive film coating on a polyethylene terephthalate (PET) base material; graphene-metal nanowires The -PET composite conductive film refers to a conductive film formed by sputtering or depositing graphene and metal nanowires on a polyethylene terephthalate (PET) base material.

According to an embodiment of the present invention, referring to FIG. 4, when the buffer layer 50 is a flexible conductive film, the flexible conductive film 50 is electrically connected to the fan-out wire layer 30. Therefore, not only the thickness of the flexible conductive film can be adjusted, but also the stress center axis 1 of the fan-out structure is on the barrier layer or the fan-out wire layer which is easily damaged when bent, so that the barrier layer or the fan-out wire layer is bent. It is not subject to tensile and compressive stress, and protects the fan-out structure from bending damage. It can also enhance the electromagnetic interference (EMI) shielding performance and electrostatic (ESD) protection effect in the fan-out area, and further improve the reliability of the fan-out area.

According to the embodiment of the present invention, the specific connection manner of the flexible conductive film 50 and the fan-out wire layer 30 is not particularly limited, and those skilled in the art can flexibly select according to actual needs. In some embodiments of the present invention, referring to FIG. 4, the flexible conductive film 50 and the fan-out wire layer 30 are electrically connected by a conductive connection. In still other embodiments of the present invention, the flexible conductive film and the fan-out wire layer may be electrically connected (not shown) by forming a via hole in the protective layer. Thus, the connection method is simple and effective, and is easy to operate.

According to the embodiment of the present invention, the material for forming the conductive connecting wire is not particularly limited, and those skilled in the art can flexibly select according to actual needs. In some embodiments of the invention, the materials forming the conductive connecting lines include, but are not limited to, conductive materials such as silver paste, copper, and the like.

According to an embodiment of the present invention, in order to further improve the flexural performance of the flexible conductive film, an opening may be provided on the flexible conductive film. Therefore, not only the electrostatic protection effect and the electromagnetic interference shielding performance are affected, but the flexural performance of the flexible conductive film can be further improved, and the reliability of use of the fan-out structure can be improved.

According to the embodiment of the present invention, the shape and the number of openings on the flexible conductive film are not required, and those skilled in the art can flexibly select according to actual needs. In some embodiments of the invention, the shape of the opening on the flexible conductive film may be a regular triangle, a diamond, a rectangle, or the like or an irregular polygon.

In another aspect of the invention, the present invention provides a flexible display panel. According to an embodiment of the present invention, the flexible display panel includes the fan-out structure of the display panel described above. Thereby, the flexible display panel has high reliability and long service life. It will be understood by those skilled in the art that the flexible display panel has all the features and advantages described above, and will not be described herein.

Of course, those skilled in the art should understand that in addition to the fan-out structure B described above, the flexible display panel further includes the structures and components necessary for the conventional flexible display panel. Referring to FIG. 5, the flexible display panel further includes a TFT substrate 70 and an OLED device. 80, the film encapsulation layer 90 and the polarizer 100 and other structures and components, and by adjusting the thickness of the thin film encapsulation layer and the polarizer, so that the stress center axis of the display area A is on the TFT substrate or the OLED device, so that the bending can be reduced Damage to the TFT substrate or OLED device.

In still another aspect of the present invention, the present invention provides a flexible display device. According to an embodiment of the invention, the flexible display device comprises the flexible display panel described above. Thereby, the flexible display device has high reliability and long service life. It will be understood by those skilled in the art that the flexible display device has all of the features and advantages described above, and will not be described herein.

According to an embodiment of the present invention, the specific type of the flexible display device is not particularly limited, and those skilled in the art can apply the flexible display panel to any display device in the field, such as a mobile phone, a tablet computer, a computer display, a game. Machines, televisions, display screens, wearable devices and other living appliances or household appliances with display functions.

It will be understood by those skilled in the art that in addition to the flexible display panel described above, the flexible display device of the present invention further includes the necessary structures and components of the conventional display device, taking the mobile phone as an example, in addition to having the flexibility described above. Outside the display panel, it can also have the structure and components of a conventional mobile phone such as a touch screen, a casing, a CPU, a camera module, a fingerprint recognition module, a sound processing system, and the like, and will not be described in detail herein.

In still another aspect of the present invention, the present invention provides a method of preparing the fan-out structure of the display panel described above. According to an embodiment of the invention, referring to Figure 6, the method comprises:

S100: providing a flexible substrate;

S200: forming a barrier layer, the barrier layer is disposed on the upper surface of the flexible substrate;

S300: forming a fan-out wire layer, the fan-out wire layer is disposed on the upper surface of the barrier layer;

S400: forming a protective layer, wherein the protective layer is disposed on the upper surface of the fan-out wire; wherein the stress center axis of the fan-out structure is located on the barrier layer or the fan-out wire layer.

According to an embodiment of the present invention, the above preparation method is simple and quick, easy to operate, mature in process, easy to industrialize, and when the fan-out structure is prepared, by adjusting the thickness of the protective layer, the stress center axis of the fan-out structure is located at the time of bending The barrier layer or the fan-out wire layer is easily damaged. Thus, when the bending, the barrier layer or the fan-out wire layer is not subjected to tensile and compressive stress, and is not easily damaged, that is, the damage of the fan-out structure is reduced, and the fan-out structure is further improved. Reliability.

According to an embodiment of the present invention, the materials for forming the flexible substrate, the barrier layer, the fan-out wire layer, and the protective layer are the same as those described above, and will not be redundantly described herein.

According to the embodiment of the present invention, the method of forming the barrier layer is not particularly limited, and those skilled in the art can flexibly select according to actual requirements. In some embodiments of the invention, methods of forming a barrier layer include, but are not limited to, methods such as chemical vapor deposition or physical vapor deposition. Thus, the process is mature, easy to operate, and easy to industrialize.

According to the embodiment of the present invention, the method of forming the fan-out wire layer is not particularly limited, and a person skilled in the art can flexibly select according to actual requirements. In some embodiments of the invention, the method of forming a fan-out wire layer may be performed by etching a metal layer to form a fan-out wire layer.

According to the embodiment of the present invention, the method for forming the protective layer is not particularly limited, and those skilled in the art can flexibly select according to actual requirements. In some embodiments of the invention, the side forming the protective layer Methods include, but are not limited to, methods such as chemical vapor deposition or physical vapor deposition. Thus, the process is mature, easy to operate, and easy to industrialize.

According to an embodiment of the present invention, referring to FIG. 7, the above method further includes a step S500 of forming a buffer layer (exemplified by a flexible conductive film as a buffer layer), and the buffer layer is disposed on the upper surface of the protective layer. Therefore, by adjusting the thickness of the buffer layer, the stress center axis of the fan-out structure is located on the barrier layer or the fan-out wire layer which is easily damaged when bent, so that the barrier layer or the fan-out wire layer is not bent when bent The tensile and compressive stress is not easily damaged, that is, the damage of the fan-out structure is reduced, and the reliability of the line in the fan-out structure is further improved.

According to the embodiment of the present invention, the method of forming the buffer layer has no limitation, and those skilled in the art can flexibly select according to actual needs. In embodiments of the invention, methods of forming a buffer include, but are not limited to, chemical vapor deposition or physical vapor deposition, such as magnetron sputtering. Thus, the process is mature, easy to operate, and easy to industrialize.

According to an embodiment of the present invention, referring to FIG. 8, when the buffer layer is a flexible conductive film, the above method further includes a step S600 of electrically connecting the flexible conductive film to the fan-out wire layer for electrical connection. Therefore, not only the thickness of the flexible conductive film can be adjusted, but also the stress center axis of the fan-out structure is on the barrier layer or the fan-out wire layer which is easily damaged when bent, and the fan-out structure is protected from bending damage and can be enhanced. The electromagnetic interference shielding performance and electrostatic protection effect of the fan-out area further improve the reliability of the fan-out area.

According to the embodiment of the present invention, the manner in which the flexible conductive film is electrically connected to the fan-out wire layer is the same as that described above, and will not be redundantly described herein.

In the present invention, the terms "installation", "connected", "connected", "fixed" and the like shall be understood broadly, and may be either a fixed connection or a detachable connection, unless explicitly stated and defined otherwise. , or integrated; can be mechanical or electrical; can be directly connected or through The intermediate medium is indirectly connected, and may be an internal connection of two elements or an interaction relationship of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means a specific feature described in connection with the embodiment or example. A structure, material or feature is included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms is not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, various embodiments or examples described in the specification, as well as features of various embodiments or examples, may be combined and combined.

Although the embodiments of the present invention have been shown and described, it is understood that the above-described embodiments are illustrative and are not to be construed as limiting the scope of the invention. The embodiments are subject to variations, modifications, substitutions and variations.

Claims

A fan-out structure of a display panel, comprising:

Flexible substrate

a barrier layer, the barrier layer is disposed on an upper surface of the flexible substrate;

Fanding a wire layer; the fan-out wire layer is disposed on an upper surface of the barrier layer;

a protective layer, the protective layer is disposed on an upper surface of the fan-out wire;

Wherein the stress center axis of the fan-out structure is located on the barrier layer or the fan-out wire layer.
The fan-out structure according to claim 1, further comprising:

a buffer layer disposed on an upper surface of the protective layer.
The fan-out structure according to claim 2, wherein the buffer layer is a flexible conductive film.
The fan-out structure according to claim 3, wherein the flexible conductive film is electrically connected to the fan-out wire layer.
The fan-out structure according to claim 3, wherein the material of the flexible conductive film is a PET-ITO conductive film or a graphene-metal nanowire-PET composite conductive film.
The fan-out structure according to claim 3, wherein the flexible conductive film is provided with an opening.
A flexible display panel comprising the fan-out structure of the display panel according to any one of claims 1 to 6.
A flexible display device comprising the flexible display panel of claim 7.
A method of preparing a fan-out structure of a display panel according to any one of claims 1 to 6, characterized in that it comprises:

Providing a flexible substrate;

Forming a barrier layer, the barrier layer being disposed on an upper surface of the flexible substrate;

Forming a fan-out wire layer, the fan-out wire layer is disposed on an upper surface of the barrier layer;

Forming a protective layer, the protective layer being disposed on an upper surface of the fan-out wire;

Wherein the stress center axis of the fan-out structure is located on the barrier layer or the fan-out wire layer.
The method according to claim 9, further comprising the step of forming a buffer layer disposed on an upper surface of said protective layer.
The method of claim 10 further comprising the step of electrically connecting said flexible conductive film to said fan-out wire layer.