CN112885975A

CN112885975A - Display substrate, preparation method thereof and display device

Info

Publication number: CN112885975A
Application number: CN202110062653.2A
Authority: CN
Inventors: 秦成杰; 张子予; 曹方旭; 王涛; 孙韬; 张嵩; 洪瑞
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2021-01-18
Filing date: 2021-01-18
Publication date: 2021-06-01

Abstract

The application provides a display substrate, a preparation method thereof and a display device, wherein the display substrate comprises: a substrate unit; the substrate unit comprises at least one substrate subunit, wherein the substrate subunit comprises a flexible substrate, a plurality of through holes which are arranged on the flexible substrate at intervals and penetrate through the flexible substrate, and a first buffer layer which is positioned above the flexible substrate; the first buffer layer extends to the side wall of the through hole to cover the side wall of the through hole; a plurality of display structures disposed above the substrate unit at intervals; a first encapsulation layer over the display structure; wherein the first encapsulation layer extends to the through hole side wall to cover the first buffer layer at the position of the through hole side wall. Through at least setting up first buffer layer and first encapsulation layer at the through-hole lateral wall between adjacent display structure, realize through the protection of multilayer protective layer through the through-hole lateral wall, strengthen the encapsulation reliability of through-hole lateral wall.

Description

Display substrate, preparation method thereof and display device

Technical Field

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

Background

Organic Light-Emitting Diode (OLED) display is a display and lighting technology developed in recent years, has the advantages of high response, high contrast, flexibility and the like, and is considered to have a wide application prospect. In the aspect of flexible display, the advantages of OLED display are better embodied due to the deformable and bendable characteristics of the OLED display device.

As one of the important development directions of flexible display products, stretchable display devices are receiving more and more attention. In the existing stretchable OLED products, the stretchable display substrate mostly adopts a large number of opening structures, and these opening structures pose a relatively large risk to the encapsulation of the device, for example, the side wall encapsulation of the opening structure is relatively weak, and is easy to fail during the stretching process, and may cause the cracking of the encapsulation layer when the flexible device is separated from the glass substrate.

Disclosure of Invention

In view of the above problems, the present application provides a display substrate, a manufacturing method thereof and a display device, which solve the technical problem that in the prior art, the display substrate is easy to fail due to the weak side wall encapsulation of the opening structure of the stretchable display substrate.

In a first aspect, the present application provides a display substrate, comprising:

a substrate unit; the substrate unit comprises at least one substrate subunit, wherein the substrate subunit comprises a flexible substrate, a plurality of through holes which are arranged on the flexible substrate at intervals and penetrate through the flexible substrate, and a first buffer layer which is positioned above the flexible substrate; the first buffer layer extends to the side wall of the through hole to cover the side wall of the through hole;

a plurality of display structures disposed above the substrate unit at intervals; the two adjacent display structures are isolated by the through hole;

a first encapsulation layer over the display structure; wherein the first encapsulation layer extends to the through hole side wall to cover the first buffer layer at the position of the through hole side wall.

In some embodiments, the display substrate further includes:

the second packaging layer is at least arranged at the position of the side wall of the through hole; wherein the second encapsulation layer covers the first encapsulation layer at the position of the side wall of the through hole; the second encapsulation layer does not overlap the display structure in a direction perpendicular to the substrate unit.

In some embodiments, in the above display substrate, the second encapsulation layer further covers the first encapsulation layer between the sidewall of the through hole and the display structure.

In some embodiments, in the above display substrate, the number of the substrate sub-units in the substrate unit is plural, and the substrate sub-units are stacked on each other such that the through holes of the substrate sub-units are communicated with each other;

wherein the first buffer layer of each of the substrate sub-units extends to the lowermost sidewall of the via to cover all the sidewalls of the via therebelow.

In some embodiments, in the above display substrate, the substrate subunit further includes:

a second buffer layer disposed between the flexible substrate and the first buffer layer; wherein the through hole further penetrates through the second buffer layer.

In some embodiments, the display substrate further includes:

a blocking structure located between the display structure and the via.

In some embodiments, in the display substrate, the second encapsulation layer covers at least a part of the barrier structure.

In some embodiments, in the above display substrate, the display structure includes a driving structure layer located above the substrate unit, and a light emitting structure layer disposed above the driving structure layer.

In some embodiments, in the display substrate, the driving structure layer is provided with a thin film transistor.

In some embodiments, in the display substrate, the light emitting structure layer includes an anode layer, a light emitting layer, and a cathode layer, which are sequentially stacked;

wherein the anode layer is electrically connected with the driving structure layer.

In a second aspect, the present application provides a method for manufacturing a display substrate, including:

providing a glass substrate;

forming a substrate unit over the glass base; wherein the substrate unit comprises at least one substrate subunit, the substrate subunit being formed by:

forming a flexible substrate over the glass base; forming a plurality of through holes which are arranged at intervals and penetrate through the flexible substrate on the flexible substrate; forming a first buffer layer over the flexible substrate; wherein the content of the first and second substances,

the first buffer layer extends into the through hole to cover the side wall of the through hole and the bottom of the through hole

A surface of the glass substrate;

forming a plurality of display structures arranged at intervals above the substrate unit; the two adjacent display structures are isolated by the through hole;

forming a first encapsulation layer over the display structure; wherein the first encapsulation layer extends into the via to cover the first buffer layer within the via;

removing the first buffer layer and the first encapsulation layer on the surface of the glass substrate at the bottom position of the through hole;

and removing the glass substrate.

In some embodiments, in the above method for manufacturing a display substrate, after the step of forming the first encapsulation layer over the display structure, the method further includes:

forming a second packaging layer on the surface of the glass substrate at least at the position of the side wall of the through hole and the bottom of the through hole; wherein the second encapsulation layer covers the first encapsulation layer within the via; the second encapsulation layer does not overlap the display structure in a direction perpendicular to the substrate unit.

In some embodiments, in the above method for manufacturing a display substrate, the number of the substrate sub-units in the substrate unit is plural, and the substrate sub-units are stacked on each other such that the through holes of the substrate sub-units are communicated with each other;

In a third aspect, the present application provides a display device comprising the display substrate according to any one of the first aspect or the display substrate prepared by the preparation method according to any one of the second aspect.

By adopting the technical scheme, the following technical effects can be at least achieved:

the application provides a display substrate, a preparation method thereof and a display device, wherein at least a first buffer layer and a first packaging layer are arranged on the side wall of a through hole between adjacent display structures, the side wall of the through hole is protected through a plurality of protective layers, the packaging reliability of the side wall of the through hole is enhanced on the basis of not influencing the tensile property of a display panel, the packaging layer of the side wall of the through hole is prevented from being broken when a flexible substrate is separated from a glass substrate, and the product yield and the reliability of the stretchable display substrate can be improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application and not to limit the application. In the drawings:

FIG. 1 is a schematic front plan view of a display substrate according to an exemplary embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of a display substrate according to an exemplary embodiment of the present disclosure;

FIG. 3 is a schematic cross-sectional view of another display substrate according to an exemplary embodiment of the present disclosure;

FIG. 4 is a schematic flow chart illustrating a method of fabricating a display substrate according to an exemplary embodiment of the present disclosure;

FIG. 5 is a schematic flow chart illustrating another method of fabricating a display substrate according to an exemplary embodiment of the present disclosure;

FIG. 6 is a cross-sectional structural view of a first intermediate structure formed at a step associated with another method of fabricating a display substrate according to an exemplary embodiment of the present application;

FIG. 7 is a cross-sectional structural view of a second intermediate structure formed at a step associated with another method of fabricating a display substrate according to an exemplary embodiment of the present application;

FIG. 8 is a cross-sectional structural view of a third intermediate structure formed in a step associated with another method of fabricating a display substrate according to an exemplary embodiment of the present application;

in the drawings, like parts are designated with like reference numerals, and the drawings are not drawn to scale.

Detailed Description

The following detailed description will be provided with reference to the accompanying drawings and embodiments, so that how to apply the technical means to solve the technical problems and achieve the corresponding technical effects can be fully understood and implemented. The embodiments and various features in the embodiments of the present application can be combined with each other without conflict, and the formed technical solutions are all within the scope of protection of the present application. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. Like reference numerals refer to like elements throughout.

It will be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

It will be understood that spatial relationship terms, such as "above", "below", "beneath", and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, then elements or features described as "below" other elements would then be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "under" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

Embodiments of the present application are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the application. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present application should not be limited to the particular shapes of regions illustrated herein, but are to include deviations in shapes that result, for example, from manufacturing.

In order to provide a thorough understanding of the present application, detailed structures and steps will be provided in the following description in order to explain the technical solutions proposed in the present application. The following detailed description of the preferred embodiments of the present application, however, will suggest that the present application may have other embodiments in addition to these detailed descriptions.

The embodiment of the application provides a display substrate. The substrate of the display substrate may be a single-layer flexible substrate structure. Referring to fig. 1 and fig. 2, the display substrate includes a substrate unit (not labeled), a display structure 12, a barrier structure 15, and a first encapsulation layer 14. The substrate unit comprises a substrate sub-unit (not shown).

The substrate subunit (not labeled in the figures) includes a flexible substrate 111, a second buffer layer 112, a via 113, and a first buffer layer 114.

The flexible substrate 111 is an organic film layer, and is selected from at least one of polyimide, negative glue, and positive glue. The flexible substrate 111 mainly functions to allow the display substrate to be bent or stretched.

A plurality of through holes 113 are disposed on the flexible substrate 111 at intervals and penetrate through the flexible substrate 111. The through hole 113 is used to achieve stretchability of the display substrate.

The second buffer layer 112 is disposed over the flexible substrate 111, and the via hole 113 penetrates the second buffer layer 112 and the flexible substrate 111. The second buffer layer 112 is used to protect the flexible substrate 111 when the via hole 113 is formed by etching. The second buffer layer 112 includes an inorganic film selected from a silicon inorganic film such as SiNx and SiOx. Due to the special material of the flexible substrate 111, the aperture of the etched through hole 113 in the second buffer layer 112 is smaller than that in the flexible substrate 111.

The through hole 113 may be (but is not limited to) an i-shaped structure, and the through hole 113 penetrating through the flexible substrate may improve the stretchability of the display substrate compared to an opening design not penetrating through the flexible substrate. The plurality of through holes 113 divides the flexible substrate into a plurality of non-open areas for disposing the display structure 12.

The first buffer layer 114 includes an inorganic film selected from a silicon inorganic film such as SiNx and SiOx. The first buffer layer 114 extends to the sidewall of the via hole 113 to cover the sidewall of the via hole 113. The first buffer layer 114 is a first protective layer on the sidewall of the via 113.

The plurality of display structures 12 are disposed above (the first buffer layer 114 of) the substrate unit at intervals, and two adjacent display structures 12 are isolated by the through hole 113, that is, the display structures 12 are disposed in a non-opening region surrounded by the through hole 113.

The display structure 12 includes a driving structure layer (not shown) and a light emitting structure layer (not shown).

The driving structure layer is located above (the first buffer layer 114 of) the substrate unit, and is provided with a thin film transistor (structure) and a capacitor (structure), and specifically includes an active layer 121, a first insulating layer 122, a gate electrode 123, a second insulating layer 124, a capacitor electrode 125, an interlayer dielectric layer 126, and a source/drain electrode 127.

The active layer 121 is a semiconductor layer such as low temperature polysilicon, single crystal silicon, or indium gallium zinc oxide, and the active layer 121 is disposed above the substrate unit.

The first insulating layer 122 is a gate insulating layer made of SiOx, and the first insulating layer 122 is located above the active layer 121 and covers the active layer 121.

The gate electrode 123 is located above the first insulating layer 122, and is located at a position corresponding to the active layer 121 (at a position corresponding to the thin film transistor) and at a position corresponding to the capacitor, to serve as a gate electrode 123 of the thin film transistor and a lower electrode of the capacitor, respectively.

The second insulating layer 124 is a dielectric layer of a capacitor, made of SiOx or SiNx, and is located above the gate electrode 123.

The capacitor electrode 125 is an upper electrode of the capacitor, the gate electrode 123 and the capacitor electrode 125 can be made of the same metal material, and the capacitor electrode 125 is disposed above the second insulating layer 124 and at the capacitor position.

The interlayer dielectric layer 126 is formed on the capacitor electrode 125 and is made of SiOx and/or SiNx.

The source-drain electrode 127 contacts the active layer 121 through a contact hole penetrating the interlayer dielectric layer 126, the second insulating layer 124, and the first insulating layer 122. The source-drain electrode 127 is for drawing out a source-drain of the thin film transistor.

The active layer 121, the first insulating layer 122, the gate electrode 123, and the source-drain electrode 127 constitute a thin film transistor.

The gate electrode 123, the second insulating layer 124, and the capacitance electrode 125 constitute a capacitance. The gate electrode 123 is a capacitor lower electrode, and the electrode capacitor is a capacitor upper electrode.

The light emitting structure layer is arranged above the driving structure layer.

In some embodiments, an organic planarization layer 131 is further disposed between the light emitting structure layer and the driving structure layer for planarizing the light emitting structure layer and reducing display defects.

The light emitting structure layer includes a pixel defining layer 132, and an anode layer 133, a light emitting layer 134, and a cathode layer 135 sequentially stacked.

The pixel defining layer 132 is used to form a pixel opening, and the pixel opening exposes the anode layer 133.

The anode layer 133 is in contact with the source-drain electrodes 127 of the driving structure layer through an anode contact hole penetrating the organic planarization layer 131, and thus is electrically connected.

The light-emitting layer 134 is an organic light-emitting layer 134, which includes an electron injection layer, an electron transport layer, an organic light-emitting material layer, a hole injection layer, and a hole transport layer.

The first encapsulation layer 14 covers the display structure 12 (mainly, the light emitting structure layer) to prevent external moisture, oxygen, and the like from entering the light emitting structure layer to cause poor display. The first encapsulation layer 14 extends to the sidewall of the via 113 to cover the first buffer layer 114 at the sidewall of the via 113. The first packaging layer 14 is a second protective layer on the sidewall of the through hole 113.

The first encapsulation layer 14 may be an inorganic material (SiOx, SiNx, or SiON) containing silicon and/or an organic material.

In some embodiments, the first encapsulation layer 14 includes a first inorganic film layer, an organic film layer on the first inorganic film layer, and a second inorganic film layer on the organic film layer. The organic film layer is formed in an ink-jet printing mode, and the flowability is good.

The barrier structure 15 is located between the display structure 12 and the through hole 113, that is, the barrier structure 15 is disposed at the periphery of the display structure 12 to block the organic film layer in the first encapsulation layer 14 from overflowing. In this case, the first encapsulation layer 14 at the sidewall position of the via 113 does not include an organic film layer, and the first encapsulation layer 14 at the sidewall position of the via 113 is an inorganic film layer, i.e., a first inorganic film layer and/or a second inorganic film layer.

In some embodiments, the material of the barrier structure 15 is the same as the material of the pixel defining layer 132 or the organic planarization layer 131. The barrier structure 15 may be formed simultaneously with the pixel defining layer 132 or the organic planarization layer 131. The light emitting layer 134, the cathode layer 135 and the inorganic film layer of the first encapsulation layer 14 are all raised at the location of the barrier structure 15.

In some embodiments, the display substrate further includes a second encapsulation layer 16. The second encapsulation layer 16 is an inorganic material (SiOx, SiNx, or SiON) and/or an organic material containing silicon, and the second encapsulation layer 16 is disposed at least at the sidewall of the through hole 113 to cover the first encapsulation layer 14 at the sidewall of the through hole 113. The second packaging layer 16 is a third protection layer on the sidewall of the through hole 113. The second encapsulation layer 16 does not cover the display structure 12, i.e. the second encapsulation layer 16 does not overlap the display structure 12 in a direction perpendicular to the substrate unit.

In some embodiments, the second encapsulation layer 16 also covers the first encapsulation layer 14 between the sidewalls of the via 113 and the display structure 12, i.e., the second encapsulation layer 16 also covers the first encapsulation layer 14 at a non-display area location outside the display structure 12.

In some embodiments, the second encapsulation layer 16 covers at least part of the barrier structure 15.

In the display substrate, the protective layer on the sidewall of the through hole 113 includes the first buffer layer 114, the first encapsulation layer 14 and the second encapsulation layer 16, so that the sidewall of the through hole is protected by the plurality of protective layers, and the encapsulation reliability of the sidewall of the through hole is enhanced on the basis of not affecting the tensile property of the display panel, so that the rupture of the encapsulation layer on the sidewall of the through hole is avoided when the flexible substrate is separated from the glass substrate, and the product yield and reliability of the stretchable display substrate can be improved.

The embodiment of the application also provides another display substrate, and the substrate of the display substrate is a double-layer flexible substrate structure. Referring to fig. 3, the display substrate includes a substrate unit (not labeled), a display structure (not labeled), a barrier structure 26 and a first packaging layer 25. The substrate unit comprises two substrate subunits (not labeled in the figure), which are stacked on top of each other, namely a first substrate subunit and a second substrate subunit (not labeled in the figure) located above the first substrate subunit (not labeled in the figure).

The first substrate subunit includes a flexible substrate 211, a second buffer layer 212, a via 213, and a first buffer layer 214.

A plurality of through holes 213 are disposed on the flexible substrate 211 at intervals, the second buffer layer 212 is disposed above the flexible substrate 211, and the through holes 213 penetrate the second buffer layer 212 and the flexible substrate 211.

The flexible substrate 211 is selected from at least one of polyimide, negative glue, or positive glue. Due to the special material of the flexible substrate 211, the aperture of the etched through hole 213 in the second buffer layer 212 is smaller than that in the flexible substrate 211.

The first buffer layer 214 extends to the sidewall of the via hole 213 to cover the sidewall of the via hole 213. The first buffer layer 214 is a first protective layer on the sidewall of the via 213.

The second substrate subunit includes a flexible substrate 221, a second buffer layer 222, a via 223, and a first buffer layer 224.

The flexible substrate 221 is positioned above the first substrate subunit such that the through-hole 223 is vertically aligned with the through-hole 213 of the first substrate subunit, and the through-hole 223 penetrates through the flexible substrate 221 and communicates with the through-hole 213.

The flexible substrate 221 is selected from at least one of polyimide, negative glue, or positive glue.

The second buffer layer 222 is disposed over the flexible substrate 221, and the through hole 223 penetrates the second buffer layer 222 and the flexible substrate 221. The second buffer layer 222 is used to protect the flexible substrate 221 when the via 223 is formed by etching. The second buffer layer 222 includes an inorganic film selected from a silicon inorganic film such as SiNx and SiOx. Due to the special material of the flexible substrate 221, the aperture of the etched through hole 223 in the second buffer layer 222 is smaller than that in the flexible substrate 221.

The first buffer layer 224 is located above the second buffer layer 222, and the first buffer layer 224 extends to the sidewall of the via 223 of the second substrate sub-unit and the sidewall of the via 213 of the first substrate sub-unit to cover the first buffer layer 214 at the position of the sidewall of the via 223 of the second substrate sub-unit and the sidewall of the via 213 of the first substrate sub-unit. The first buffer layer 224 includes an inorganic film selected from a silicon inorganic film such as SiNx and SiOx. The first buffer layer 224 is a second protective layer on the sidewall of the via 213 of the first substrate subunit and a first protective layer on the sidewall of the via 223 of the second substrate subunit.

A plurality of display structures are arranged above the substrate unit at intervals, and two adjacent display structures are isolated by the through hole 213 and the through hole 223, namely, the display structures are arranged in a non-opening area surrounded by the through hole 213 and the through hole 223.

The display structure includes a driving structure layer (not labeled) and a light emitting structure layer (not labeled).

The driving structure layer is located above the substrate unit and includes a thin film transistor (structure) and a capacitor (structure), and the driving structure layer specifically includes an active layer 231, a first insulating layer 232, a gate electrode 233, a second insulating layer 234, a capacitor electrode 235, an interlayer dielectric layer 236, and a source-drain electrode 237.

In some embodiments, an organic planarization layer 241 is further disposed between the light emitting structure layer and the driving structure layer for planarizing the light emitting structure layer and reducing display defects.

The light emitting structure layer includes a pixel defining layer 242, and an anode layer 243, a light emitting layer 244, and a cathode layer 245 sequentially stacked.

The pixel defining layer 242 is used to form a pixel opening, and the anode layer 243 is exposed from the pixel opening.

The anode layer 243 is electrically connected to the source/drain electrode 237 of the driving structure layer through an anode contact hole penetrating the organic planarization layer 241.

The light emitting layer 244 is an organic light emitting layer, and includes an electron injection layer, an electron transport layer, an organic light emitting material layer, a hole injection layer, and a hole transport layer.

The first encapsulation layer 25 covers the display structure (mainly the light emitting structure layer) to prevent external moisture, oxygen, and the like from entering the light emitting structure layer to cause poor display. The first encapsulation layer 25 extends to the via 223 and the via 213 sidewall to cover the first buffer layer 214 at the via 213 sidewall position and the first buffer layer 224 at the via 223 sidewall position. The first encapsulation layer 25 is a third layer of protection layer on the sidewalls of the via 213 of the first substrate subunit and a second layer of protection layer on the sidewalls of the via 223 of the second substrate subunit.

The first encapsulation layer 25 may be an inorganic material (SiOx, SiNx, or SiON) containing silicon and/or an organic material.

In some embodiments, the first encapsulation layer 25 includes a first inorganic film layer, an organic film layer on the first inorganic film layer, and a second inorganic film layer on the organic film layer. The organic film layer is formed in an ink-jet printing mode, and the flowability is good.

The barrier structure 26 is located between the display structure and the through hole 213, that is, the barrier structure 26 is disposed at the periphery of the display structure to block the organic film layer in the first encapsulation layer 25 from overflowing. In this case, the first encapsulation layer 25 at the sidewall positions of the through-

holes

213 and 223 does not include an organic film layer, and the first encapsulation layer 25 at the sidewall positions of the through-

holes

213 and 223 is an inorganic film layer, i.e., a first inorganic film layer and/or a second inorganic film layer.

In some embodiments, the material of the barrier structure 26 is the same as the material of the pixel defining layer 242 or the organic planarization layer 241. The barrier structure 26 may be formed simultaneously with the pixel defining layer 242 or the organic planarization layer 241. The light emitting layer 244, the cathode layer 245 and the inorganic film layer of the first encapsulation layer 25 all form a protrusion at the location of the barrier structure 26.

In some embodiments, the display substrate further comprises a second encapsulation layer 27. The second encapsulation layer 27 is an inorganic material (SiOx, SiNx, or SiON) and/or an organic material containing silicon, and the second encapsulation layer 27 is disposed at least on the sidewall of the through hole 213 and the sidewall of the through hole 223 to cover the first encapsulation layer 25 at the sidewall of the through hole 213 and the sidewall of the through hole 223. The second packaging layer 27 is a fourth protection layer on the sidewall of the via 213 and a third protection layer on the sidewall of the via 223. The second encapsulation layer 27 does not cover the display structure, i.e. the second encapsulation layer 27 does not overlap the display structure in a direction perpendicular to the substrate unit.

In some embodiments, the second encapsulation layer 27 also covers the first encapsulation layer 25 between the via 213 and via 223 sidewalls and the display structure, i.e. the second encapsulation layer 27 also covers the first encapsulation layer 25 at non-display area locations outside the display structure.

In some embodiments, the second encapsulation layer 27 covers at least part of the barrier structure 26. In the display substrate, the protective layer on the sidewall of the through hole 213 of the first substrate subunit has the first buffer layer 214 of the first substrate subunit, the first buffer layer 224, the first encapsulation layer 25 and the second encapsulation layer 27 of the second substrate subunit, and the protective layer on the sidewall of the through hole 223 of the second substrate subunit has the first buffer layer 224, the first encapsulation layer 25 and the second encapsulation layer 27 of the second substrate subunit. The through hole side walls are protected through the multiple protective layers, the packaging reliability of the through hole side walls is enhanced on the basis that the tensile property of the display panel is not influenced, the packaging layers of the through hole side walls are prevented from being broken when the flexible substrate is separated from the glass substrate, and the product yield and the reliability of the stretchable display substrate can be improved.

In some embodiments, the substrate of the display substrate is not limited to the single-layer and double-layer flexible substrate structures, and may be a three-layer or more flexible substrate, which may further improve the flexibility of the substrate.

Correspondingly, the substrate unit comprises three or more substrate subunits, and the substrate subunits are arranged in a stacked manner, so that the through holes of the substrate subunits are aligned in the vertical direction to realize the mutual communication of the through holes of the substrate subunits; each substrate subunit comprises a flexible substrate, a plurality of through holes which are arranged on the flexible substrate at intervals and penetrate through the flexible substrate, and a first buffer layer which is positioned above the flexible substrate.

The first buffer layer of each substrate subunit extends to the sidewall of the lowest through hole to cover the sidewalls of all the through holes below the first buffer layer.

The protective layer on the side wall of the through hole of the substrate subunit at the lowest part is the thickest so as to protect the position with the largest stress (the position where the protective layer is most easy to break) in the glass substrate glass process, thereby further enhancing the packaging reliability of the side wall and not influencing the tensile property of the device.

The display substrate that this application embodiment provided sets up first buffer layer and first encapsulation layer at least through the through-hole lateral wall between adjacent display structure, further realizes through multilayer protective layer protection through-hole lateral wall, on the basis that does not influence display panel's tensile properties, further strengthens the encapsulation reliability of through-hole lateral wall to avoid the fracture of through-hole lateral wall encapsulation layer when flexible substrate and glass substrate separate, can further improve the product yield and the reliability of tensile display substrate.

Embodiments of the present application further provide a method for manufacturing a display substrate, where the following "patterning" includes processes such as coating a photoresist, mask exposure, developing, etching, and stripping the photoresist. The "deposition" may be selected from any one or more of sputtering, evaporation and chemical vapor deposition, and the etching may be performed using any one or more selected from dry etching and wet etching.

Referring to fig. 2 and fig. 4, a method for manufacturing a display substrate according to an embodiment of the present disclosure includes the following steps:

step S110: providing a glass substrate;

step S120: forming a substrate unit over a glass substrate; wherein the substrate unit comprises a substrate subunit, the substrate subunit being formed by: forming a flexible substrate 111 over the glass base; forming a plurality of through holes 113 which are arranged at intervals and penetrate through the flexible substrate 111 on the flexible substrate 111; forming a first buffer layer 114 over the flexible substrate 111; the first buffer layer 114 extends into the via 113 to cover the sidewall of the via 113 and the surface of the glass substrate at the bottom of the via 113.

The flexible substrate 111 is formed over the glass base by means of coating.

The flexible substrate 111 is an organic film layer, and is selected from at least one of polyimide, negative glue, and positive glue. The flexible substrate mainly functions to allow the display substrate to be bent or stretched. The flexible substrate 111 is a flexible material, which is easily curled during the process, and the flexible substrate 111 needs to be coated on a glass substrate since the flexible substrate 111 may be formed with a through hole during the subsequent process.

Subsequently, the flexible substrate 111 is subjected to a patterning process, and a plurality of through holes 113 arranged at intervals and penetrating through the flexible substrate 111 are formed in the flexible substrate 111.

In some embodiments, before the step of forming the plurality of through holes 113 disposed at intervals and penetrating through the flexible substrate 111 on the flexible substrate 111, the method further includes: a second buffer layer 112 is formed over the flexible substrate 111. At this time, the via hole 113 formed later also penetrates the second buffer layer 112. The second buffer layer 112 is used to protect the flexible substrate 111 when the via hole 113 is formed by etching. The second buffer layer 112 includes an inorganic film selected from a silicon inorganic film such as SiNx and SiOx.

Subsequently, a layer of the first buffer layer 114 is deposited over the flexible substrate 111, the first buffer layer 114 covering the entire substrate such that the first buffer layer 114 extends into the via 113 to cover the via 113 sidewalls and the glass base surface at the bottom position of the via 113.

Step S130: forming a plurality of spaced apart display structures 12 over the substrate unit; wherein, two adjacent display structures 12 are isolated by the through hole 113.

Specifically, step S130 includes the following steps: forming a driving structure layer over the substrate unit; and forming a light emitting structure layer above the driving structure layer.

Forming a drive structure layer over the substrate unit, comprising:

(a) forming an active layer 121 (including deposition and patterning) over the substrate unit;

(b) forming (depositing) a first insulating layer 122 over the active layer 121;

(c) forming a gate electrode 123 (including deposition and patterning) over the first insulating layer 122;

(d) forming (depositing) a second insulating layer 124 over the gate electrode 123;

(e) forming a capacitive electrode 125 (including deposition and patterning) over the second insulating layer 124;

(f) forming (depositing) an interlayer dielectric layer 126 over the capacitor electrode 125;

(g) forming a contact hole penetrating the interlayer dielectric layer 126, the second insulating layer 124, and the first insulating layer 122 (patterning process);

(h) source and drain electrodes 127 (including deposition and patterning) are formed within the contact holes.

While the source-drain electrode contact holes are formed, the interlayer dielectric layer 126, the second insulating layer 124 and the first insulating layer 122 remaining in the through holes can be removed at the same time.

Forming a light emitting structure layer over the driving structure layer, comprising:

(a) forming (depositing) an organic planarization layer 131 over the driving structure layer;

(b) forming an anode contact hole (patterning) penetrating the organic planarization layer 131;

(c) forming an anode layer 133 (including deposition and patterning) filled in the anode contact hole;

(d) forming a pixel definition layer 132 (including deposition and patterning) around the anode layer;

(e) forming (depositing) a light emitting layer 134 over the anode layer 133;

(f) a cathode layer 135 is formed (deposited) over the light emitting layer 134.

In some embodiments, in the step of forming the light emitting structure layer over the driving structure layer, the blocking structure 15 is also simultaneously formed between the display structure 12 and the via hole 113 while the organic planarization layer 131 or the pixel defining layer 132 is formed. Both the light emitting layer 134 and the cathode layer 135 form a protrusion at the location of the barrier structure 15.

Step S140: forming a first encapsulation layer 14 over the display structure 12; the first encapsulation layer 14 extends into the through hole 113 to cover the first buffer layer 114 in the through hole 113.

In some embodiments, the first encapsulation layer 14 includes a first inorganic film layer, an organic film layer on the first inorganic film layer, and a second inorganic film layer on the organic film layer. The organic film layer is formed in an ink-jet printing mode, and the flowability is good. The blocking structure 15 may block the organic film layer in the first encapsulation layer 14 from overflowing. The inorganic film layer of the first encapsulation layer 14 forms a protrusion at the location of the barrier structure 15.

Step S150: the first buffer layer 114 and the first encapsulation layer 14 on the surface of the glass substrate at the bottom position of the via hole 113 are removed.

The first buffer layer 114 and the first encapsulation layer 14 on the surface of the glass substrate at the bottom position of the via hole 113 are removed by patterning.

In some embodiments, step S140 is followed by: forming a second encapsulation layer 16 on the sidewall and the bottom of the through hole 113; wherein the second encapsulation layer 16 covers the first encapsulation layer 14 within the via 113. The second encapsulation layer 16 does not cover the display structure 12, i.e. the second encapsulation layer 16 does not overlap the display structure 12 in a direction perpendicular to the substrate unit. Correspondingly, the second encapsulation layer 16 at the bottom position of the through hole 113 is simultaneously removed in step S150.

In some embodiments, the second encapsulation layer 16 may be formed simultaneously with the first encapsulation layer 14 (forming a thicker encapsulation layer structure), and then portions of the second encapsulation layer over the display structure 12 are etched away by an etching process, leaving only the first encapsulation layer 14 over the display structure 12.

In some embodiments, in step S130, an evaporation process is used to form the light emitting layer 134 and the cathode layer 135 of the light emitting structure, and in this case, in step S130, the light emitting layer 134 and the cathode layer 135 are also formed by evaporation at the bottom of the through hole 113, but in step S150, the first buffer layer 114, the first encapsulation layer 14, the second encapsulation layer 16, the light emitting layer 134, and the cathode layer 135 at the bottom of the through hole 113 are all removed at the same time.

Step S160: and removing the glass substrate.

In order to realize the stretching effect of the flexible substrate, the glass substrate needs to be removed, and the removal mode can adopt a laser peeling mode.

Referring to fig. 5, another method for manufacturing a display substrate according to an embodiment of the present disclosure includes the following steps:

step S210: a glass substrate 28 is provided.

Step S220: referring to fig. 6, a substrate unit is formed over a glass substrate 28; wherein the substrate unit comprises two substrate subunits, the substrate subunits formed by the steps of: forming a flexible substrate 211 (or 221) over the glass base 28; forming a plurality of through holes 213 (or 223) arranged at intervals and penetrating through the flexible substrate 211 (or 221) on the flexible substrate 211 (or 221); forming a first buffer layer 214 (or 224) over the flexible substrate 211 (or 221); wherein the first buffer layer 214 (or 224) extends into the through hole 213 (or 223) to cover the sidewall of the through hole 213 (or 223) and the surface of the glass substrate 28 at the bottom position of the through hole 213 (or 223).

The two substrate subunits are arranged one above the other, respectively a first substrate subunit and a second substrate subunit above the first substrate subunit.

First, a first substrate unit is formed, including: forming a flexible substrate 211 over the glass base 28 by means of coating; forming a plurality of through holes 213 which are arranged at intervals and penetrate through the flexible substrate 211 on the flexible substrate 211; a first buffer layer 214 is formed over the flexible substrate 211, the first buffer layer 214 extending into the through-hole 213 to cover the side wall of the through-hole 213 and the surface of the glass base 28 at the bottom position of the through-hole 213.

Subsequently, forming a second substrate unit over the first substrate unit, including: forming a flexible substrate 221 over the first substrate unit by means of coating; forming a plurality of through holes 223 arranged at intervals and penetrating through the flexible substrate 221 on the flexible substrate 221, wherein the through holes 223 are vertically aligned with the through holes 213 of the first substrate unit; a first buffer layer 224 is formed over the flexible substrate 221, the first buffer layer 224 extending into the via 223 and the via 213 of the first substrate unit to cover the via 223 sidewall and the via 213 sidewall of the first substrate unit, and the surface of the glass base 28 at the bottom position of the via 223 (or the via 213). That is, the first buffer layer 224 covers the first buffer layer 214 at the position of the via 223 of the first substrate unit.

The flexible substrate 211 and the flexible substrate 221 are organic film layers and are selected from at least one of polyimide, negative glue or positive glue. The flexible substrate mainly functions to allow the display substrate to be bent or stretched. The flexible substrate 211 and the flexible substrate 221 are flexible materials, and are easily curled during the process, and since the flexible substrate 211 and the flexible substrate 221 are formed with through holes during the subsequent process, the flexible substrate 211 needs to be coated on the glass base 28.

The first buffer layer 214 and the first buffer layer 224 include inorganic films selected from silicon inorganic films such as SiNx and SiOx.

In some embodiments, before the step of forming the plurality of through holes 213 disposed at intervals and penetrating through the flexible substrate 211 on the flexible substrate 211 when the first substrate unit is formed, the method further includes: a second buffer layer 212 is formed over the flexible substrate 211. At this time, the via hole 213 formed later also penetrates the second buffer layer 212. The second buffer layer 212 is used to protect the flexible substrate 211 when the through hole 213 is formed by etching. The second buffer layer 212 includes an inorganic film selected from a silicon inorganic film such as SiNx and SiOx.

In some embodiments, before the step of forming the plurality of through holes 223 disposed at intervals and penetrating through the flexible substrate 221 on the flexible substrate 221 when forming the second substrate unit, the method further includes: a second buffer layer 222 is formed over the flexible substrate 221. At this time, the via 223 formed later also penetrates the second buffer layer 222. The second buffer layer 222 is used to protect the flexible substrate 221 when the via 223 is formed by etching. The second buffer layer 222 includes an inorganic film selected from a silicon inorganic film such as SiNx and SiOx.

Step S230: forming a plurality of display structures arranged at intervals above the substrate unit; wherein, the adjacent two display structures are isolated by the through hole 213 (and the through hole 214).

Specifically, step S230 includes the following steps: forming a driving structure layer over the first buffer layer 224; and forming a light emitting structure layer above the driving structure layer.

Forming a driving structure layer over the substrate unit includes:

(a) forming an active layer 231 (including deposition and patterning) over the substrate unit;

(b) forming (depositing) a first insulating layer 232 over the active layer 231;

(c) forming a gate electrode 233 over the first insulating layer 232 (including deposition and patterning);

(d) forming (depositing) a second insulating layer 234 over the gate electrode 233;

(e) forming a capacitor electrode 235 (including deposition and patterning) over the second insulating layer 234;

(f) forming (depositing) an interlayer dielectric layer 236 over the capacitor electrode 235;

(g) forming a contact hole penetrating the interlayer dielectric layer 236, the second insulating layer 234, and the first insulating layer 232 (patterning process);

(h) source and drain electrodes 237 (including deposition and patterning) are formed within the contact holes.

While the source-drain electrode contact hole is formed, the interlayer dielectric layer 236, the second insulating layer 234 and the first insulating layer 232 remaining in the via hole may be removed at the same time.

(a) forming (depositing) an organic planarization layer 241 over the driving structure layer;

(b) forming an anode contact hole (patterning) penetrating the organic planarization layer 241;

(c) forming an anode layer 243 (including deposition and patterning) filled in the anode contact holes;

(d) forming a pixel defining layer 242 (including deposition and patterning) around the anode layer 243;

(e) forming (depositing) a light emitting layer 244 over the anode layer 243;

(f) a cathode layer 245 is formed (deposited) over the light emitting layer 244.

In some embodiments, in the step of forming the light emitting structure layer over the driving structure layer, the barrier structure 26 is also simultaneously formed between the display structure and the via hole 213 and the via hole 223 when the organic planarization layer 241 or the pixel defining layer 242 is formed. The light emitting layer 244 and the cathode layer 245 form a protrusion at the location of the barrier structure 26.

Step S240: referring to fig. 7, a first packaging layer 25 is formed over the display structure; wherein the first encapsulation layer 25 extends into the via 213 (and the via 214) to cover the first buffer layer 214 (and the first buffer layer 224) within the via 213 (and the via 214).

In some embodiments, the first encapsulation layer 25 includes a first inorganic film layer, an organic film layer on the first inorganic film layer, and a second inorganic film layer on the organic film layer. The organic film layer is formed in an ink-jet printing mode, and the flowability is good. The blocking structure 26 may block the organic film layer in the first encapsulation layer 25 from overflowing. The inorganic film layer of the first encapsulation layer 25 forms a protrusion at the location of the barrier structure 26.

Step S250: referring to fig. 8, the first buffer layer 214 (and the first buffer layer 224) and the first encapsulation layer 25 on the surface of the glass substrate 28 at the bottom of the via 213 are removed.

The first buffer layer 214 (and the first buffer layer 224) and the first encapsulation layer 25 at the bottom position of the via hole 213 are removed by the patterning process.

In some embodiments, step S240 is followed by: forming a second encapsulation layer 27 on the sidewall and the bottom of the via hole 213; wherein the second encapsulation layer 27 covers the first encapsulation layer 25 within the via 213. The second encapsulation layer 27 does not cover the display structure, i.e. the second encapsulation layer 27 does not overlap the display structure in a direction perpendicular to the substrate unit. Correspondingly, the second encapsulation layer 27 at the bottom position of the through hole 213 is simultaneously removed in step S250.

In some embodiments, the second encapsulation layer 27 covers at least part of the barrier structure 26.

In some embodiments, the second encapsulation layer 27 may be formed simultaneously with the first encapsulation layer 25 (forming a thicker encapsulation layer structure), and then portions of the second encapsulation layer above the display structure are etched away by an etching process, leaving only the first encapsulation layer 27 above the display structure.

In some embodiments, in step S230, the light emitting layer 244 and the cathode layer 245 of the light emitting structure are formed by evaporation, and in this case, in step S230, the light emitting layer 244 and the cathode layer 245 are also formed by evaporation at the bottom of the through hole 213, but in step S250, the first buffer layer 214 (and the first buffer layer 224), the first encapsulation layer 25, the second encapsulation layer 27, the light emitting layer 244 and the cathode layer 245 at the bottom of the through hole 213 are all removed at the same time.

Step S260: the glass substrate 28 is removed.

According to the preparation method of the stretchable display substrate, the through hole side wall between the adjacent display structures is at least provided with the first buffer layer and the first packaging layer, the through hole side wall is protected through the multiple protective layers, the packaging reliability of the through hole side wall is enhanced on the basis that the stretching performance of the display panel is not influenced, the breakage of the packaging layer of the through hole side wall is avoided when the flexible substrate is separated from the glass substrate, and the product yield and the reliability of the stretchable display substrate can be improved.

For the method for manufacturing the display substrate with the substrate unit including more than two substrate sub-units (i.e. more than two layers of flexible substrates), the substrate sub-units can be formed by sequentially stacking the substrate sub-units according to the embodiment of the two substrate sub-units.

The embodiment of the application also provides a display device, which comprises the display substrate described in any one of the above embodiments or the display substrate prepared by using the preparation method described in any one of the above embodiments.

In some embodiments, the display device is a display panel, and the display panel includes the display substrate and the glass cover plate.

In some embodiments, the display device may include a display panel and a housing, the display panel being connected with the housing, e.g., the display panel being embedded in the housing. The display device can be any device with a display function, such as a mobile phone, a tablet computer, a television, a notebook computer, a digital photo frame, a navigator and the like.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application. Although the embodiments disclosed in the present application are described above, the embodiments are merely used for the understanding of the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A display substrate, comprising:

2. The display substrate of claim 1, further comprising:

3. The display substrate of claim 2, wherein the second encapsulation layer further covers the first encapsulation layer between the via sidewall and the display structure.

4. The display substrate according to claim 1, wherein the number of the substrate sub-units in the substrate unit is plural, and the substrate sub-units are stacked on each other such that the through holes of the substrate sub-units communicate with each other;

5. The display substrate of claim 1, wherein the substrate subunit further comprises:

6. The display substrate of claim 2, further comprising:

a blocking structure located between the display structure and the via.

7. The display substrate of claim 6, wherein the second encapsulation layer covers at least a portion of the barrier structure.

8. The display substrate of any one of claims 1 to 7, wherein the display structure comprises a driving structure layer over the substrate unit, and a light emitting structure layer disposed over the driving structure layer.

9. The display substrate of claim 8, wherein the driving structure layer is provided with a thin film transistor.

10. The display substrate of claim 8, wherein the light emitting structure layer comprises an anode layer, a light emitting layer and a cathode layer sequentially stacked;

11. A method for preparing a display substrate is characterized by comprising the following steps:

providing a glass substrate;

forming a flexible substrate over the glass base; forming a plurality of through holes which are arranged at intervals and penetrate through the flexible substrate on the flexible substrate; forming a first buffer layer over the flexible substrate; wherein the first buffer layer extends into the via to cover the via sidewall and the glass substrate surface at the via bottom location;

and removing the glass substrate.

12. The method of claim 11, wherein after the step of forming the first encapsulation layer over the display structure, the method further comprises:

13. The method of manufacturing a display substrate according to claim 11, wherein the number of the substrate sub-units in the substrate unit is plural, and the respective substrate sub-units are arranged one on another so that the through holes of the respective substrate sub-units communicate with each other;

14. A display device comprising the display substrate according to any one of claims 1 to 10 or a display substrate produced by the production method according to any one of claims 11 to 13.