Flexible substrate, method for producing the same and flexible display device

A flexible substrate is provided. The flexible substrate includes: a flexible layer, wherein the flexible layer has a plurality of notches which have a first maximum width along a stretching direction in a stretched state of the flexible layer and have a second maximum width along the stretch direction in an unstretched state of the flexible layer, and wherein the first maximum width is greater than the second maximum width. A flexible display apparatus including the above flexible substrate and a method for producing the flexible substrate are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a Section 371 National Stage Application of International Application No. PCT/CN2019/071441, filed on Jan. 11, 2019, entitled “FLEXIBLE SUBSTRATE, METHOD FOR PRODUCING THE SAME AND FLEXIBLE DISPLAY DEVICE”, which claims the benefit of Chinese Patent Application No. 201810491889.6 filed on May 21, 2018 with the China National Intellectual Property Administration, the whole disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the field of liquid crystal display technology, and more particularly to a flexible substrate, a method for producing the flexible substrate and a flexible display apparatus.

BACKGROUND

In recent years, flexible display technology develops rapidly. One of factors for achieving the flexible display is to use a flexible substrate and to produce display elements onto the flexible substrate. For example, when the elements are produced on the flexible substrate provided with hole and groove regions, no elements can be arranged in the positions of the hole and groove regions. And pitches between holes and grooves are typically greater than aperture of pixels such that high resolution cannot be achieved.

SUMMARY

Embodiments of the present disclosure provide a flexible substrate including: a flexible layer, wherein the flexible layer has a plurality of notches which have a first maximum width along a stretch direction in a stretched state of the flexible layer and have a second maximum width along the stretch direction in an unstretched state of the flexible layer, and wherein the first maximum width is greater than the second maximum width.

In some embodiments, the flexible substrate further includes fillers in the notches, wherein there is a weak adhesion interface between the flexible layer and the fillers.

In some embodiments, the flexible layer and the fillers are made from different materials, respectively.

In some embodiments, the plurality of notches further include a plurality of groups of notches and each group of the plurality of groups of notches includes a plurality of notches separated from each other and arranged linearly in the flexible layer.

In some embodiments, in the stretched state of the flexible layer, each group of notches are communicated together to form a hole.

In some embodiments, the hole has a rhombic shape in a cross section thereof parallel to the flexible layer.

In some embodiments, the plurality of groups of notches include rows of notches and columns of notches that are arranged alternately in the flexible layer and separated from each other.

In some embodiments, depths of the notches in the flexible layer are less than or equal to thickness of the flexible layer.

In some embodiments, the flexible substrate further includes: a stretchable base material on which flexible layer is provided.

In some embodiments, orthogonal projections of the notches in the flexible layer on the stretchable base material are located on solid part of the stretchable base material.

In some embodiments, the flexible layer includes: a plurality of functional element regions in which functional elements are arranged; and non-functional element regions between adjacent functional element regions, the notches being arranged in the non-functional element regions.

Embodiments of the present disclosure also provide a flexible display apparatus, including: the flexible substrate as describe in any one of the above embodiments.

Embodiments of the present disclosure also provide a method for producing a flexible substrate, the method including: forming a flexible layer on a base plate; forming notches in the flexible layer; and transferring the flexible layer formed with the notches from the base plate to a stretchable base material to form the flexible substrate.

In some embodiments, before forming the notches in the flexible layer, the method further includes: performing a first drying process on the flexible layer, wherein 10% to 80% of solvent in the flexible layer is removed in the first drying process.

In some embodiments, after forming the notches in the flexible layer, the method further includes: performing a second drying process on the flexible layer, wherein more than 90% of the solvent in the flexible layer is removed in the second drying process.

In some embodiments, before performing the second drying process, the method further includes: forming a filling layer on the flexible layer formed with the notches, wherein a first material forming the flexible layer and a second material forming the filling layer are configured such that there is a weak adhesion interface between the flexible layer and the filling layer; and etching and ashing the filling layer to expose the flexible layer while maintaining part of the filling layer filled in the notches.

In some embodiments, the method further includes: forming a buffer layer on the exposed flexible layer.

In some embodiments, the second drying process further includes curing the flexible layer.

In some embodiments, the method further includes: stretching the stretchable substrate with the flexible layer adhered thereon such that the notches expand and deform until the flexible layer cracks along the notches.

Through the following description of the present disclosure with reference to accompanying drawings, other objects and advantages of the present disclosure will be apparent and it may be helpful to understand the present disclosure comprehensively.

DETAILED DESCRIPTION OF EMBODIMENTS

Technical solutions of the present disclosure and those in the related art will further be described in detail below with reference to the drawings and embodiments. Throughout the description, same or similar components are represented by same or similar reference numerals. The following description of embodiments of the present disclosure with reference to the accompanying drawings is intended to explain the generic concept of the present disclosure, instead of limiting the present disclosure.

In addition, in the following detailed description, numerous specific details are set forth for interpretation and to provide a full understanding to the disclosed embodiments. However, it is obvious that one or more embodiments can be implemented without these specific details. In other instances, known structures and devices are illustrated in a simplified drawing.

Embodiments of the present disclosure relate to a flexible substrate and a method for producing the flexible substrate and a flexible display apparatus.

In accordance with the concept of the present disclosure, it provides a flexible substrate. The flexible substrate at least includes a flexible layer. The flexible layer has a plurality of notches. When the flexible layer is stretched, the notches have a first maximum width along a stretch direction. When the flexible layer is not stretched, the notches have a second maximum width along the stretch direction. The first maximum width is greater than the second maximum width.

It also provides a method for producing a flexible substrate. The method at least includes: forming a flexible layer on a base plate; forming notches in the flexible layer; and transferring the flexible layer formed with the notches from the base plate to a stretchable base material to form the flexible substrate.

In addition, it also provides a flexible display apparatus including the flexible substrate as described above.

FIG. 1Ais a schematic top view showing a structure of a flexible substrate in an unstretched state according to an embodiment of the present disclosure.FIG. 1Bis a schematic top view showing a structure of the flexible substrate shown inFIG. 1Ain a stretched state. As shown inFIG. 1A, the flexible substrate provided by the embodiments of the present disclosure includes a flexible layer10. The flexible layer10includes a plurality of notches11formed therein. In some embodiments, these notches11may be formed in groups, for example, a group11′ of notches and a group11″ of notches. When the flexible layer10is in the unstretched state (or the flexible substrate is in the unstretched state), the notches11are openings with smaller size (for example called as gaps), as shown inFIG. 1A; in contrast, when the flexible layer10is in the stretched state (for example along directions indicated by arrows inFIG. 1B), each group of notches11are stretched into an opening with larger size (for example it can be called as a hole), as shown inFIG. 1B. The hole has a greater aperture than the gap.

It should be noted that, in the present disclosure, the term of “gap” represents an opening that is formed in the flexible layer and has a smaller aperture. The smaller aperture is at least less than the diameters of the functional elements (for example for display) provided on the flexible substrate. The term of “hole” represents an opening that has a larger aperture and is formed by expanding at least one opening with smaller aperture in the flexible layer when the flexible layer is stretched. The term of “aperture” represents the maximum diameter of a regular or irregular cross section of the “gap” or “hole”. In addition, when the flexible layer10is in the stretched state, the maximum aperture of the hole is greater than the maximum aperture of the gap along the stretch direction.

Considering that the notches11or the groups11′ and11″ of notches may not have regular shapes such as rectangle, circle, in order to accurately express change of the notches11or the groups11′ and11″ of notches before they are stretched and after they are stretched, a concept of the maximum width may be introduced. For example, as shown inFIG. 1B, each of the stretched notches11has not uniform width along the stretch direction (for example the left-right direction inFIG. 1B) and its maximum width (i.e., a first maximum width) along the stretch direction is indicated by H1. In contrast, the maximum width (i.e., a second maximum width) of the notches11that are not stretched shown inFIG. 1Ain the stretch direction (for example, corresponding toFIG. 1B, i.e., the left-right direction) is H2. Thus, the first maximum width H1of the notches11along the stretch direction in the stretched state of the flexible layer10is significantly greater than the second maximum width H2of the notches11along the stretch direction in the unstretched state of the flexible layer10. As an example, in order to achieve higher resolution, the second maximum width H2may be at least less than the profile size (for example diameter) of the functional elements provided on the flexible substrate.

By means of the above structure design, when the flexible substrate provided by the embodiments of the present disclosure is stretched by force (for example, is stretched to have a special magnitude of strain), the notches11(or groups11′,11″ . . . of notches) in the flexible layer10are expanded into the holes from the gaps until the flexible layer10is cracked at the notches11(or groups11′,11″ . . . of notches) or regions around the notches11, to provide deformation required for stretching of the flexible substrate. In this way, it can reduce, or even avoid deformation of the flexible layer10at other positions, to prevent the functional elements (for example used for display, such as TFT elements) at other positions of the flexible layer10from being affected by stretching strains. It should be noted that the flexible layer10may be presented in a form of single layer with a certain thickness, however, the present disclosure is not limited to this. For example, the flexible layer10may alternatively have a multi-layer structure. The flexible layer10may be made from stretchable and deformable materials such as polyimide (PI).

In accordance with embodiments of the present disclosure, the flexible layer may include a plurality of groups of notches. As shown inFIG. 1A, the flexible substrate10includes a plurality of groups of notches (or a plurality of notch groups11′,11″ . . . ) and each group (for example11′) of the plurality of groups of notches11includes a plurality of notches11separated from each other and arranged linearly in the flexible layer10. For example, the plurality of notches11in one group11′ of notches are designed in the flexible layer10in form of “dashed lines”, that is, the plurality of notches11are arranged in one straight line and there is smaller pitch between adjacent notches11in the straight line (for example, the pitch is smaller than length of a single notch11in the straight line). These groups of notches are formed in the flexible layer10at positions where no functional elements (for example, used for display) are formed. For example, these groups of notches are arranged at a side of the positions where the functional elements15(for example, shown in dashed lines inFIG. 6AandFIG. 6B) are arranged in the flexible layer10or around these positions. In this way, when the flexible substrate is stretched, parts of the flexible layer10that are located between adjacent notches in each group of notches will crack along the direction in which the group of notches are arranged such that each group of notches are communicated to form a hole with a larger aperture, to further provide deformation required for the flexible substrate.

As an example, the flexible layer10may include a plurality of functional element regions16and non-functional element regions17between adjacent functional element regions16. Functional elements (they represent elements for implementing respective circuit functions or parts thereof, such as functional elements for display, TFT, pixel structures, electrodes, even traces) are arranged in the plurality of functional element regions16. The notches11are arranged in the non-functional element regions17. No functional elements are provided in the non-functional element regions17. In this way, the deformation of the notches11may provide amount of deformation required for the flexible substrate so as to prevent functional elements in the functional element regions16from being destroyed due to excessive deformation. This arrangement may utilize space between adjacent functional elements more sufficiently to provide notches.

In addition, a plurality of groups of notches11may be arranged depending on strain requirements of deformation of the flexible substrate to control the positions and spaces of cracked faces for stretching of the flexible substrate. For example, the plurality of groups of notches may include rows of notches and columns of notches that are arranged alternately in the flexible layer and separated from each other. As shown inFIG. 1A, one group11′ of notches are arranged in one column in the flexible layer10while another group11″ of notches adjacent to the group11′ of notches are arranged in one row in the flexible layer10. And any adjacent two groups of notches are separated from each other whether in the column direction, or in the row direction. Certainly, in other embodiments of the present disclosure, the plurality of groups of notches may be arranged in any other suitable forms. The embodiments of the present disclosure are not limited to this.

In some embodiments, when the flexible layer10is stretched, each group of notches11may form a hole with a large aperture by expanding and communicating a plurality of gaps with small apertures. For example, as shown inFIG. 1B, one hole having a rhombic shape with a large aperture (i.e., the hole has a rhombic shape in a cross section parallel to the flexible layer10) is formed. Certainly, in other embodiments of the present disclosure, expanding structure and expanded shape of the notches may alternatively use other designs of structures and shapes. Embodiments of the present disclosure are not limited to this.

In the flexible substrate provided by embodiments of the present disclosure, the notches11are filled with fillers12. The flexible layer10is made from a first material and the fillers12are made from a second material. The first material is different from the second material. For example, the adhesion interface between the flexible layer10made from the first material and the fillers12made from the second material should have weak adhesion property. In this way, the fillers12may be separated easily from the notches11when the flexible substrate is stretched, for cracking of the flexible layer10at the notches11. It should be noted that the term of “weak adhesion interface” means that any two (same or different) materials are formed into films one after another and the adhesion force formed between the two materials is less than internal cohesive force in the film formed by each material itself. In an example, the first material may be an organic material such as PI and the second material may be an inorganic material. In another example, the first material and the second material are two inorganic materials that can form the weak adhesion interface between them, respectively. In a further example, the first material and the second material are two organic materials that can form the weak adhesion interface between them respectively. It should be noted that when one of the first material and the second material is an organic material and the other of them is an inorganic material, it needs to avoid any chemical or physical bonding reaction between the first material and the second material in essence. When the first material and the second material are both organic materials, it needs to prevent the first material and the second material from being cross-linked neither chemically nor physically during forming the films. The embodiments of the present disclosure are not limited to the case that the first material and the second material are different materials, for example, if the first material and the second material are same but the above “weak adhesion interface” can be achieved by a certain process to cause the flexible layer10to tend to crack at the notches11when it is stretched, it will be possible that the first material and the second material are same.

In the flexible substrate provided by the embodiments of the present disclosure, depths of the notches in the flexible layer may be less than or equal to the thickness of the flexible layer10itself.FIG. 2Ais a schematic cross sectional view showing a structure of the flexible substrate shown inFIG. 1Ataken along line K-K′ inFIG. 1A.FIG. 2Bis a schematic cross-sectional view showing a structure of the flexible substrate shown inFIG. 2Ain a stretched state.FIG. 3Ais a schematic cross-sectional view showing a structure of the flexible substrate in the unstretched state according to another embodiment of the present disclosure.FIG. 3Bis a schematic cross-sectional view showing a structure of the flexible substrate shown inFIG. 3Ain a stretched state. For the sake of clarity, only one notch11formed in the flexible layer10is shown schematically. In the embodiment shown inFIG. 2AandFIG. 2B, depths of the notches11in the flexible layer10are less than the thickness of the flexible layer10itself, that is, the notches11in the flexible layer10are formed as grooves and the grooves are filled with fillers12therein. In this case, when the flexible layer10is stretched to have a certain magnitude of strain, the flexible layer10is torn along side walls of the grooves such that the flexible layer10is deformed to crack at the notches11. In the embodiment shown inFIG. 3AandFIG. 3B, the depths of the notches11in the flexible layer10are equal to the thickness of the flexible layer10itself, that is, the notches11in the flexible layer10are formed as through openings through the flexible layer10and the through openings are filled with fillers12. In this case, when the flexible layer10is stretched to have a certain magnitude of strain, the flexible layer10is broken along the side walls of the through openings so as to be deformed to crack at the notches11. In addition, it should be noted that, the notches11have cross sectional shapes of inverted trapezoid in embodiments shown inFIG. 1, however, in other embodiments, the notches11may have any other suitable cross sectional shapes. The present disclosure is not limited to this.

In addition, in some embodiments of the present disclosure, the flexible substrate further includes: a stretchable base material20and the flexible layer10is arranged on the stretchable base material20, as shown inFIG. 2AtoFIG. 3B. As an example, projections of the notches11in the flexible layer10on the stretchable base material20may be located on solid part of the stretchable base material20. That is, no openings are provided on the positions on the stretchable base material20corresponding to the notches11, which is helpful to enhance strength of the flexible substrate.

In this way, the flexible substrate provided by embodiments of the present disclosure may in particular be used as, for example, a base substrate in a flexible OLED or liquid crystal display screen.

Further, embodiments of the present disclosure also provide a flexible display apparatus including the flexible substrate described in any one of the above embodiments. In particular, the above flexible display apparatus may be any products or components having flexible display functions, such as a flexible liquid crystal display apparatus, a liquid crystal display, a liquid crystal TV, or an organic electroluminescent display apparatus, an organic electroluminescent display, an organic electroluminescent TV, a digital camera frame, a cell phone, a tablet computer, a navigator.

Thus, in the flexible substrate and the flexible display apparatus provided by embodiments of the present disclosure, a plurality of notches are formed in the flexible layer of the flexible substrate. When the flexible substrate is stretched, these notches can be expanded until the flexible layer cracks at these notches to provide deformation required for the flexible substrate, so as to reduce or even prevent functional elements (for example used for display) on the flexible substrate from being affected by stretching strains, so as to improve display quality of the flexible display apparatus including the flexible substrate. And a plurality of groups of notches separated from each other are formed on the flexible layer and each group of notches include a plurality of notches separated from each other and arranged linearly in the flexible layer. When the flexible substrate is stretched, parts between adjacent notches in each group of notches in the flexible layer crack along the direction in which the group of notches are arranged such that each group of notches form a hole with larger aperture, to further provide the deformation required for the flexible substrate. In addition, by designing the specific positions of the notches on the flexible layer in advance, the position and space of the cracking faces of the flexible layer when the flexible substrate is stretched can be controlled. Further, by designing expandable notches in a form of gaps with small aperture on the flexible layer, the resolution of wiring can be enhanced in comparison with, for example, hole and groove regions in the related art.

Meanwhile, embodiments of the present disclosure also provide a method for producing a flexible substrate.FIG. 4is a diagram showing a method for producing a flexible substrate according to an embodiment of the present disclosure.FIG. 5is a flow chart showing a method for producing a flexible substrate according to an embodiment of the present disclosure. The method for producing the flexible substrate described in the above embodiments of the present disclosure will below be described with reference toFIG. 4andFIG. 5. It should be noted that optional steps are represented by dashed block inFIG. 5. The skilled person in the art may select or may not select these steps as required.

The method for producing the flexible substrate in which the present disclosure is involved will below be described with reference toFIG. 4andFIG. 5.

The step S10: forming a flexible layer10on a base plate30.

In the above step S10, the base plate30may be for example a glass base plate. The raw material of the flexible layer may be a solution of material that is suitable for producing the flexible layer and has stretchable property and flexible property, for example, solution of PI material. In some embodiments of the present disclosure, the flexible layer (or called as a first film layer) may be formed on the back plate by coating. However, in other embodiments, any suitable processes for forming the flexible layer may alternatively used, such as dipping or adhering.

The step S20: forming notches (or called as recesses)11in the flexible layer10.

In the above step S20, the recesses may be formed in the flexible layer for example by imprinting process. The imprinting process may be implemented by available nanometer imprinting apparatus in the art. The imprinting process may be performed to form recesses11in the flexible layer10(notches in the flexible layer are formed in finished flexible substrate). Certainly, in accordance with embodiments of the present disclosure, in the above step S20, other than the imprinting process in the embodiments shown in figures, the flexible layer may alternatively be processed by any other suitable processes for forming recesses (such as lasering or plasma processes) as long as structures including notches11can be formed in the flexible layer. In addition, according to embodiments of the present disclosure, the notches11may have any suitable shapes of cross sections. The present disclosure is not limited to this.

The step S30: transferring the flexible layer10formed with the notches11from the base plate30to a stretchable base material20.

The step S40: stretching the stretchable substrate20with the flexible layer10adhered thereon such that the notches11expand and deform until the flexible layer10cracks (for example cracks partly) along the notches11to provide deformation required for the flexible substrate.

As shown inFIG. 4andFIG. 5, after the step S10and before the step S20, the method provided by the embodiments of the present disclosure may further include the following steps.

The step S20A: performing a first drying process on the flexible layer10to form a flexible layer initially dried, wherein 10% to 80% of solvent in the flexible layer is removed in the first drying process.

The first drying process on the flexible layer is beneficial to formation of the recesses in the subsequent steps. It should be noted that the main function of “drying process” described herein is to remove solvent in the flexible layer. Substantially 10% to 80% of solvent in the flexible layer may be removed in the first drying process on the flexible layer. And the apparatus for performing the first drying process may be suitable drying apparatus in the art, for example, a vacuum dryer.

As shown inFIG. 4andFIG. 5, after the step S20and before the step S30, the method provided by the embodiments of the present disclosure may further include the following steps.

The step S20B: performing a second drying process on the flexible layer10which has the notches11and which has been dried initially, wherein more than 90% of the solvent in the flexible layer is removed in the second drying process.

By means of the above step S20B, the flexible layer10which has been dried twice is formed, so as to form the flexible layer with notches in the flexible substrate. In addition, the apparatus for performing the second drying process may be suitable drying apparatus in the art, for example, a vacuum dryer. After the step, the flexible layer with notches of the flexible substrate may be formed. Further, in the above step S20B, the second drying process may further include curing the flexible layer10which has been dried twice, for example, when the flexible layer uses precursor of PI (i.e., poly(amic-acid) (PAA)), PAA is converted into PI by curing. And finally the flexible layer10that is dried twice (and cured) may have thickness in range of 5 μm to 20 μm. In accordance with embodiments of the present disclosure, the thickness of the notches11may be less than or equal to thickness of the flexible layer10. In this way, the flexible layer10dried twice may be the flexible layer in the flexible substrate as described in the above embodiments of the present disclosure, and the notches11may be the notches formed in the flexible layer of the flexible substrate as described in the above embodiments of the present disclosure.

In addition, in the method provided by the embodiments of the present disclosure, before forming the flexible layer10on the base plate30, a releasing layer or a sacrifice layer may be produced on the base plate30, for convenience of transferring of the flexible layer in subsequent steps.

According to some embodiments, as shown inFIG. 4andFIG. 5, after the step S20and before the step S30, the method provided by the embodiments of the present disclosure may further include the following step S21and step S22.

The step S21: forming a filling layer12′ on the flexible layer10including the notches11, wherein a first material forming the flexible layer10and a second material forming the filling layer12′ are configured such that there is a weak adhesion interface between the flexible layer and the filling layer.

In the step S21, the adhesion interface between the flexible layer10made from the first material and the fillers12made from the second material should have weak adhesion property with respect to each other. In this way, the fillers12may be separated easily from the notches11when the flexible substrate is stretched, for cracking of the flexible layer10at the notches11. In an example, the first material may be an organic material such as PI and the second material may be an inorganic material. In another example, the first material and the second material are two inorganic materials that can form a weak adhesion interface between them, respectively. In a further example, the first material and the second material are two organic materials that can form the weak adhesion interface between them, respectively.

The step S22: etching and ashing the filling layer12′ to expose the flexible layer10while maintaining part of the filling layer12′ filled in the notches11.

After performing the above step S22, a part of the filling layer12′ at least fills the notches11of the flexible layer10to form fillers12.

After performing the above steps S21and S22, the thickness for etching and ashing should be greater than or equal to the thickness of the filling layer12′ on the flexible layer10such that after the step has been performed, only the notches11in the flexible layer10are filled with fillers made from the filling material.

According to some embodiments, as shown inFIG. 4andFIG. 5, after the step S22and before the step S30, the method provided by the embodiments of the present disclosure may further include the following step.

The step S23: forming a buffer layer50on the exposed flexible layer10.

After performing the above step S23, a planarization surface formed by the flexible layer10and the fillers12in the notches11in combination may be obtained.

After the step S23, elements used for display such as TFT (thin film transistor) may be produced on the exposed surface of the flexible layer10(or the surface of the buffer layer50). The functional elements15(for example used for display) such as TFT (thin film transistor) are formed on the position on the surface of the flexible layer10where no notches are provided. And subsequently, the elements produced on the surface of the flexible layer10are evaporated and encapsulated.

In the method provided by embodiments of the present disclosure, by using the above steps S21to S23, the flexible layer10and the fillers12filled in the notches11are made from different materials having weak adhesion interface between them, respectively. It not only provides flatness of the film layer, but also tends to tear the flexible layer10along the side wall of the notches11(i.e., the weak adhesion interface between the flexible layer10and the fillers12) when the flexible layer10is stretched to have a special amount of strain, so as to cause deformation and crack at the notches11. In this way, the flexible layer10that has been dried twice may be the flexible layer in the flexible substrate described by the above embodiments of the present disclosure. The notches11may be notches formed in the flexible layer in the flexible substrate described in the above embodiments of the present disclosure while the part of the filling layer charged in the notches11may be fillers12charged in the notches of the flexible layer in the flexible substrate described in the above embodiments of the present disclosure.

Thus, in the method for producing the flexible substrate provided by embodiments of the present disclosure, a plurality of notches are formed in the flexible layer of the flexible substrate. When the flexible substrate is stretched, these notches can be expanded and deformed until the flexible layer cracks at these notches to provide deformation required for the flexible substrate, so as to reduce or even prevent functional elements used for display on the flexible substrate from being affected by stretching strains, so as to improve display quality of the flexible display apparatus including the flexible substrate. And a plurality of groups of notches separated from each other are formed on the flexible layer and each group of notches include a plurality of notches separated from each other and arranged linearly in the flexible layer. When the flexible substrate is stretched, parts between adjacent notches in each group of notches in the flexible layer crack along the direction in which the group of notches are arranged such that each group of notches form a hole with larger aperture, to further provide the deformation required for the flexible substrate.

In addition, in the method for producing the flexible substrate provided by embodiments of the present disclosure, positions and spaces of the cracking faces when the flexible substrate is stretched can be controlled by designing the specific positions of the notches on the flexible layer in advance.

Further, in the method for producing the flexible substrate provided by embodiments of the present disclosure, by designing expandable notches in form of gaps with small aperture on the flexible layer, the resolution of wiring can be enhanced in comparison with, for example, hole and groove regions in the related art.

Although some embodiments of the present disclosure have been shown and explained, the skilled person in the art will appreciated that these embodiments can be modified without departing from principles and spirits of the present disclosure. Scope of the present disclosure will be defined by the appended claims and equivalents thereof.