Display substrate and preparation method thereof

Abstract

The invention discloses a display substrate and a preparation method of the display substrate. The display substrate comprises a substrate body, a conductive layer located on one side of the substrate body and a protective layer located on the side, away from the substrate body, of the conductive layer. The conductive layer comprises a plurality of connecting lines, the connecting lines are arranged at intervals in the first direction and extend in the second direction, and the first direction and the second direction intersect; in the first direction, the orthographic projection of the plurality of connecting lines on the plane where the display substrate is located is located in the orthographic projection of the protective layer on the plane where the display substrate is located; wherein the protective layer comprises at least two protective sub-layers, the molecular weights of materials of the at least two protective sub-layers are different, and the molecular weight of the material of the protective sub-layer close to one side of the substrate is smaller than that of the material of the adjacent protective sub-layer, so that the problem that the connecting line of the existing display substrate is seriously corroded can be solved.

Description

Technical Field

[0001] This article relates to but is not limited to the field of display technology, and in particular to a display substrate and a preparation method thereof. Background Art

[0002] After packaging, display products undergo high-temperature and high-humidity reliability testing. Statistics on reliability failures revealed that the edges of the connecting wires on the display substrate were severely corroded, resulting in low yield rates for display products. Summary of the Invention

[0003] The embodiments of the present disclosure provide a display substrate and a method for manufacturing the same, which can solve the problem of severe corrosion of connecting lines on existing display substrates.

[0004] In one aspect, an embodiment of the present disclosure provides a display substrate, comprising a substrate, a conductive layer located on one side of the substrate, and a protective layer located on a side of the conductive layer away from the substrate; the conductive layer comprising a plurality of connecting lines, the plurality of connecting lines being arranged at intervals along a first direction and extending along a second direction, the first direction intersecting the second direction; in the first direction, the orthographic projections of the plurality of connecting lines on a plane where the display substrate is located are located within the orthographic projection of the protective layer on the plane where the display substrate is located;

[0005] The protective layer includes at least two protective sublayers, the molecular weights of the materials of the at least two protective sublayers are different, and the molecular weight of the material of the protective sublayer close to the substrate is smaller than the molecular weight of the material of the adjacent protective sublayer.

[0006] In some exemplary embodiments, the material of the protective sublayer includes at least a thermosetting resin; the at least two protective sublayers include a first protective sublayer and a second protective sublayer, and the first protective sublayer is closer to the substrate than the second protective sublayer, and the viscosity of the first protective sublayer is less than that of the second protective sublayer.

[0007] In some exemplary embodiments, the at least two protective sublayers include a first protective sublayer and a second protective sublayer, and the first protective sublayer is closer to the substrate than the second protective sublayer;

[0008] The thickness of the first protective sub-layer is smaller than the thickness of the second protective sub-layer.

[0009] In some exemplary embodiments, the thickness of the first protective sub-layer is in a range of 1.0 micrometers to 2.5 micrometers; and the thickness of the second protective sub-layer is in a range of 8.0 micrometers to 30 micrometers.

[0010] In some exemplary embodiments, the at least two protective sublayers include a first protective sublayer and a second protective sublayer, and the first protective sublayer is closer to the substrate than the second protective sublayer;

[0011] The orthographic projection of the edge of the connecting line extending along the second direction on the plane where the display substrate is located is located within the orthographic projection of the first protective sublayer on the plane where the display substrate is located, and the first protective sublayer contacts at least part of the surface of the connecting line away from the substrate.

[0012] In another aspect, an embodiment of the present disclosure provides a method for preparing a display substrate. The method comprises:

[0013] forming a conductive layer on one side of the substrate, the conductive layer comprising a plurality of connecting lines, the plurality of connecting lines being arranged at intervals along a first direction and extending along a second direction, the first direction intersecting the second direction;

[0014] A protective layer is formed on the side of the conductive layer away from the substrate, and in the first direction, the orthographic projections of the multiple connecting lines on the plane where the display substrate is located are located within the orthographic projection of the protective layer on the plane where the display substrate is located; the protective layer includes at least two protective sublayers, and the molecular weights of materials of at least two of the protective sublayers are different, and the molecular weight of the material of the protective sublayer close to the substrate is smaller than the molecular weight of the material of the protective sublayer adjacent to it.

[0015] In some exemplary embodiments, forming a protective layer on a side of the conductive layer away from the substrate includes:

[0016] forming a first protective sublayer on a side of the conductive layer away from the substrate;

[0017] forming a second protective sublayer on a side of the first protective sublayer away from the substrate;

[0018] The viscosity of the first protective sub-layer is less than the viscosity of the second protective sub-layer.

[0019] In some exemplary embodiments, before forming the protective layer on the side of the conductive layer away from the substrate, the preparation method further includes:

[0020] The substrate on which the conductive layer is formed is subjected to a modification process.

[0021] In some exemplary embodiments, modifying the substrate having the conductive layer formed thereon comprises:

[0022] Hexamethyldisilane gas is used to spray the surface of the substrate on which the conductive layer is formed.

[0023] In some exemplary embodiments, the spraying time ranges from 20 seconds to 30 seconds.

[0024] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. Other advantages of the present application can be realized and obtained by the solutions described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0026] Figure 1 This is a schematic diagram of the front structure of a display device according to an embodiment of the present disclosure;

[0027] Figure 2 This is a schematic diagram of the back structure of a display device according to an embodiment of the present disclosure;

[0028] Figure 3 A partial cross-sectional view of a display device according to an embodiment of the present disclosure Figure 1 ;

[0029] Figure 4 A partial cross-sectional view of a display device according to an embodiment of the present disclosure Figure 2 ;

[0030] Figures 5A to 5E 、 Figures 6A to 6B Schematic diagram of the manufacturing process of the display device according to the embodiment of the present disclosure;

[0031] Figure 7 Schematic diagram of the structure of the spliced ​​display device according to an embodiment of the present disclosure.

[0032] Reference numerals:

[0033] 100-display substrate, 200-driving circuit board, 300-display device;

[0034] 10-substrate, 10a-first surface, 10b-side, 10c-second surface, 11-conductive layer, 111-connecting line, 111a-first line segment, 111b-second line segment, 111c-third line segment, 12-protective layer, 12-1-first protective sublayer, 12-2-second protective sublayer, 12A-first side, 12B-second side; 20-first electrode, 30-protective layer, 50-flexible circuit board, 60-drying device, 70-spraying device, 80-cleaning device, 90-coating device. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The embodiments can be implemented in a variety of different forms. A person of ordinary skill in the art can easily understand the fact that the method and content can be transformed into one or more forms without departing from the purpose and scope of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the contents described in the following embodiments. In the absence of conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other in any way.

[0036] In the drawings, the size of one or more components, layer thicknesses, or regions may be exaggerated for clarity. Therefore, one embodiment of the present disclosure is not necessarily limited to these dimensions, and the shapes and sizes of components in the drawings do not reflect true proportions. Furthermore, the drawings schematically illustrate idealized examples, and one embodiment of the present disclosure is not limited to the shapes or values ​​shown in the drawings.

[0037] The ordinal numbers such as "first," "second," and "third" in this disclosure are provided to avoid confusion among constituent elements, and are not intended to limit the number. The "plurality" in this disclosure includes two or more.

[0038] In this disclosure, for convenience, words and phrases indicating orientation or positional relationships, such as "middle," "upper," "lower," "front," "back," "vertical," "horizontal," "top," "bottom," "inside," and "outside," are used to illustrate the positional relationships of constituent elements with reference to the accompanying drawings. This is merely for the convenience of describing this specification and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as a limitation of this disclosure. The positional relationships of constituent elements are appropriately changed according to the direction in which the constituent elements are described. Therefore, the words and phrases are not limited to those described in the specification and can be appropriately replaced according to the circumstances.

[0039] In this disclosure, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed, removable, or integral connections; mechanical or electrical connections; direct connections, indirect connections through intermediaries, or internal communication between two components. Those skilled in the art will understand the meaning of these terms in this disclosure based on the specific circumstances.

[0040] In this disclosure, a transistor refers to a device comprising at least three terminals: a gate electrode, a drain electrode, and a source electrode. A transistor has a channel region between a drain electrode (drain electrode terminal, drain region, or drain) and a source electrode (source electrode terminal, source region, or source), and current can flow through the drain electrode, the channel region, and the source electrode. In this disclosure, the channel region refers to the region through which current primarily flows.

[0041] In the present disclosure, the first electrode may be a drain electrode and the second electrode may be a source electrode, or vice versa. The functions of "source electrode" and "drain electrode" may be interchanged when using transistors with opposite polarity or when the direction of current changes during circuit operation. Therefore, in the present disclosure, "source electrode" and "drain electrode" may be interchanged.

[0042] In this disclosure, "electrically connected" includes components connected together via an element having some electrical function. There are no particular limitations on the "element having some electrical function" as long as it enables the transfer of electrical signals between the connected components. Examples of "element having some electrical function" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements having one or more functions.

[0043] In this disclosure, "parallel" refers to a state where the angle formed by two straight lines is greater than -10° and less than 10°, and thus includes a state where the angle is greater than -5° and less than 5°. Furthermore, "perpendicular" refers to a state where the angle formed by two straight lines is greater than 80° and less than 100°, and thus includes a state where the angle is greater than 85° and less than 95°.

[0044] In this disclosure, the terms "film" and "layer" may be interchanged. For example, "conductive layer" may be replaced with "conductive film." Similarly, "insulating film" may be replaced with "insulating layer."

[0045] The term "about" in the present disclosure refers to a numerical value that is not strictly defined and allows for process and measurement errors.

[0046] An embodiment of the present disclosure provides a display substrate. The display substrate includes a substrate, a conductive layer located on one side of the substrate, and a protective layer located on a side of the conductive layer away from the substrate. The conductive layer includes a plurality of connecting lines, the plurality of connecting lines being arranged at intervals along a first direction and extending along a second direction, the first direction intersecting the second direction. In the first direction, the orthographic projections of the plurality of connecting lines on the plane where the display substrate is located are located within the orthographic projection of the protective layer on the plane where the display substrate is located.

[0047] The protective layer includes at least two protective sublayers, the molecular weights of the materials of the at least two protective sublayers are different, and the molecular weight of the material of the protective sublayer close to the substrate is smaller than the molecular weight of the material of the adjacent protective sublayer.

[0048] The display substrate provided by the embodiment of the present disclosure is provided with a protective layer, which includes at least two protective sublayers, and the molecular weight of the material of the protective sublayer provided close to the substrate side is smaller than the molecular weight of the material of the protective sublayer adjacent thereto. This can improve the adhesion between the material of the protective sublayer and the edge of the connecting line, prevent water and oxygen from invading the interior of the display substrate through the edge, and ensure that the protective layer has sufficient protective strength, thereby improving the water and oxygen resistance of the display substrate, improving the corrosion of the connecting line, and improving the yield rate of the display substrate.

[0049] Figure 1 is a schematic diagram of the front structure of the display device according to an embodiment of the present disclosure, Figure 2 Schematic diagram of the back structure of the display device of the embodiment of the present disclosure. The front of the display device can be the display surface of the display device, and the back of the display device can be the side opposite to the display surface. Figure 1 and Figure 2 As shown, the display device 300 may include a display substrate 100 and a driving circuit board 200. The driving circuit board 200 may be configured as a driving integrated circuit (IC) that drives the display substrate 100 to display. The driving circuit board 200 may include a gate driving circuit, a source driving circuit, a timing controller, and a power supply circuit. The driving circuit board 200 is electrically connected to the display substrate 100 and is configured to output corresponding signals to control the display substrate 100 to display.

[0050] like Figure 1As shown, the display substrate 100 may include a display area AA and a peripheral area BB disposed at least on one side of the display area AA. For example, the peripheral area BB may be located on one, two, or three sides of the display area AA, or the peripheral area BB may be disposed around the display area AA. A plurality of pixels P and a plurality of signal lines (not shown) may be arranged in an array in the display area AA, and the plurality of signal lines are electrically connected to the plurality of pixels P. Each pixel P may include at least one light-emitting device PX, which may be, for example, an inorganic light-emitting diode. The size of the inorganic light-emitting diode may be less than 500 microns, or less than 100 microns. For example, the light-emitting device PX may be a red light-emitting diode, a green light-emitting diode, or a blue light-emitting diode. For example, each pixel P may include a red sub-pixel, a green sub-pixel, and a blue sub-pixel, each of which is composed of a red light-emitting diode, a green light-emitting diode, and a blue light-emitting diode, respectively. For example, the light-emitting device PX may be a Mini LED (mini Light-Emitting Diode), or a Micro LED (Micro Light-Emitting Diode), or the like.

[0051] like Figure 1 、 Figure 2 As shown, the display substrate 100 may further include a plurality of first electrodes 20 and a plurality of connecting lines 111. The plurality of first electrodes 20 may be arranged on the front surface of the display substrate 100. For example, the first electrode 20 may be an end portion of a signal line located in the display area of ​​the display substrate extending to an edge, or an electrode arranged separately from the signal line.

[0052] For example, multiple first electrodes 20 and multiple connecting wires 111 can be arranged in groups one by one. The first end of each connecting wire 111 can be electrically connected to the first end of one first electrode 20, and the second end of the connecting wire 111 can extend from the front of the display device to the back of the display device and be electrically connected to the flexible printed circuit 50 (FPC). The second end of the first electrode 20 can be configured to be electrically connected to the light-emitting device PX.

[0053] like Figure 2 As shown, the driving circuit board 200 is bound to the back of the display substrate 100, and the light-emitting device PX located on the front of the display substrate 100 is electrically connected to the driving circuit board 200 located on the back of the display substrate 100 through the connecting line 111. Such a design can reduce the size of the peripheral area of ​​the display device and increase the screen-to-body ratio of the display device.

[0054] In some possible exemplary embodiments, the display substrate 100 may further include a plurality of second electrodes, which may be disposed on the back surface of the display substrate 100. For example, the plurality of first electrodes 20, the plurality of connecting lines 111, and the plurality of second electrodes may be arranged in groups, with the first end of each connecting line 111 being electrically connected to the first end of a first electrode 20, and the second end of the connecting line 111 being electrically connected to the first end of a second electrode. The second end of the first electrode 20 may be configured to be electrically connected to the light-emitting device PX, and the second end of the second electrode may be configured to be electrically connected to the flexible printed circuit 50 (FPC), although this disclosure is not limited thereto.

[0055] Figure 3 A partial cross-sectional view of a display device according to an embodiment of the present disclosure Figure 1 , Figure 4 A partial cross-sectional view of a display device according to an embodiment of the present disclosure Figure 2 , Figure 4 for Figure 2 The cross-sectional diagram at the mark AA is shown in FIG. Figure 3 、 Figure 4 As shown, in the embodiment of the present disclosure, within the plane of the display substrate, the width direction of the connecting line 111 is defined as a first direction X, and the length direction of the connecting line 111 is defined as a second direction Y. In the embodiment of the present disclosure, the thickness direction of the display substrate is defined as a third direction Z. The thickness direction of the display substrate is also the thickness direction of the display device. In the embodiment of the present disclosure, the first direction X, the second direction Y, and the third direction Z are mutually perpendicular.

[0056] like Figure 3 、 Figure 4 As shown, the display substrate may include a substrate 10, a conductive layer 11 disposed on one side of the substrate 10, and a protective layer 12 disposed on a side of the conductive layer 11 away from the substrate 10. The conductive layer 11 may include a plurality of first electrodes 20 and a plurality of connecting lines 111. Figure 3 、 Figure 4 , the schematic diagram shows a design scheme in which the multiple first electrodes 20 and the multiple connecting lines 111 are different layer structures, and the conductive layer 11 may include two conductive sublayers. In some examples, the multiple first electrodes 20 and the multiple connecting lines 111 may be located in the same film layer, which is not limited in this disclosure.

[0057] In an exemplary embodiment, the substrate 10 may be a flexible substrate or a rigid substrate. The rigid substrate may be, but is not limited to, one or more of glass and quartz. The flexible substrate may be, but is not limited to, one or more of polyethylene terephthalate, polyethylene terephthalate, polyetheretherketone, polystyrene, polycarbonate, polyarylate, polyarylate, polyimide, polyvinyl chloride, polyethylene, textile fiber, and the like.

[0058] In an exemplary embodiment, the material of the conductive layer 11 can be a metal material, such as any one or more of silver (Ag), copper (Cu), aluminum (Al), titanium (Ti) and molybdenum (Mo), or an alloy material of the above metals, such as aluminum neodymium alloy (AlNd) or molybdenum niobium alloy (MoNb), and can be a single-layer structure or a multi-layer composite structure, such as Ti / Al / Ti, etc.

[0059] In an exemplary embodiment, the thickness of the conductive layer 11 may be in a range of 0.3 micrometers to 0.5 micrometers. For example, the thickness of the conductive layer 11 may be 0.4 micrometers.

[0060] In an exemplary embodiment, the material of the protective layer 12 can be thermosetting resin, etc. The protective layer 12 can prevent water and oxygen from invading the display substrate from the edges of the connecting wires, thereby improving the reliability of the electrical connection of the connecting wires.

[0061] In an exemplary embodiment, the protective layer 12 may have a thickness ranging from 10 micrometers to 32.5 micrometers.

[0062] In an exemplary embodiment, Figure 3 As shown, the substrate 10 may include a first surface 10a, a second surface 10c opposite the first surface 10a, and a side surface 10b connecting the first surface 10a and the second surface 10c. The connecting line 111 may include a first segment 111a, a second segment 111b, and a third segment 111c connected in sequence. The first segment 111a is disposed on the first surface 10a, the second segment 111b is disposed on the side surface 10b, and the third segment 111c is disposed on the second surface 10c. A plurality of first electrodes 20 are disposed on the first surface 10a, and the plurality of first electrodes 20 are electrically connected to the plurality of first segments 111a in a one-to-one correspondence. The plurality of third segments 111c may be electrically connected to the flexible circuit board 50.

[0063] In an exemplary embodiment, Figure 3 As shown, there is a gap L between the protective layer 12 and the flexible circuit board 50 along the second direction Y, and L can be greater than or equal to 500 microns; setting this gap can ensure that the end of the third segment 111c bound to the flexible circuit board 50 is exposed, thereby avoiding the adverse effect of the protective layer on the binding connection process between the flexible circuit board 50 and the end of the third segment 111c.

[0064] In an exemplary embodiment, Figure 3 、 4 As shown, the protective layer 12 may include a first protective sublayer 12-1 and a second protective sublayer 12-2 stacked along the thickness direction of the display substrate, with the first protective sublayer 12-1 being closer to the substrate 10 than the second protective sublayer 12-2. The first protective sublayer 12-1 has a first viscosity, and the second protective sublayer 12-2 has a second viscosity, wherein the first viscosity is less than the second viscosity. The thickness of the first protective sublayer 12-1 may range from 1.0 microns to 2.5 microns. For example, the thickness of the first protective sublayer 12-1 may be 2.0 microns, and the thickness of the first protective sublayer 12-1 is greater than the thickness of the conductive layer. The thickness of the second protective sublayer 12-2 may range from 8.0 microns to 30 microns. In the first direction X, the orthographic projection of the connecting wire on the plane where the display substrate is located may be located within the orthographic projection of the first protective sublayer 12-1 on the plane where the display substrate is located. The first protective sublayer 12-1 can completely cover the edge of the connecting wire, thereby preventing water and oxygen from corroding the connecting wire and other external circuits of the display substrate. The second protective sublayer 12-2 can ensure that the overall strength of the protective layer 12 is high. In the embodiment of the present disclosure, in a structure where the thickness of the first protective sublayer 12-1 is not a single value, the maximum thickness of the first protective sublayer 12-1 along the thickness direction of the display substrate is defined as the thickness of the first protective sublayer 12-1.

[0065] In an exemplary embodiment, the material of the first protective sublayer 12-1 can be a short-chain, small-molecule material. For example, the material of the first protective sublayer 12-1 can include an unsaturated polyester resin. The small-molecule material can ensure that the material is in full contact with the rough surface of the connecting line 111 obtained by the patterning process, and can improve the waterproof and oxygen-resistant performance of the connecting line 111. The material of the second protective sublayer 12-2 can be a long-chain, large-molecule material. For example, the material of the second protective sublayer 12-2 can include a saturated polyester resin. In some examples, the material of the second protective sublayer 12-2 can also include silicone, etc., which can improve the stiffness, strength, etc. of the second protective sublayer.

[0066] In an exemplary embodiment, Figure 4 As shown, the first protective sublayer 12-1 has a first side surface 12A and a second side surface 12B that are relatively arranged. The second side surface 12B is in contact with the second protective sublayer 12-2, and the flatness of the second side surface 12B is better than the flatness of the first side surface 12A, which can ensure the bonding strength between the first protective sublayer 12-1 and the second protective sublayer 12-2.

[0067] like Figure 4As shown, the orthographic projection of the edge of the connecting line 111 extending along the second direction Y on the plane where the display substrate is located is located within the orthographic projection of the first protective sublayer 12-1 on the plane where the display substrate is located, and the first protective sublayer 12-1 is in contact with at least part of the surface of the connecting line 111 away from the substrate 10. The first protective sublayer 12-1 can completely cover the edge of the connecting line, thereby preventing water and oxygen from corroding the connecting line and other external circuits of the display substrate.

[0068] The following is an illustrative explanation through the preparation process of the display device. The "patterning process" mentioned in the present disclosure includes processing processes such as coating photoresist, mask exposure, development, etching, and stripping photoresist. The deposition process can be any one or more of sputtering, evaporation, and chemical vapor deposition, the coating process can be any one or more of spraying, spin coating, and inkjet printing, and the etching process can be any one or more of dry etching and wet etching, which are not limited in the present disclosure. "Thin film" refers to a layer of thin film made by deposition, coating or other processes of a certain material on a substrate. If the "thin film" does not require a patterning process during the entire production process, the "thin film" can also be called a "layer". If the "thin film" requires a patterning process during the entire production process, it is called a "thin film" before the patterning process and a "layer" after the patterning process. The "layer" after the patterning process contains at least one "pattern". In the exemplary embodiments of the present disclosure, "the orthographic projection of B is within the range of the orthographic projection of A" or "the orthographic projection of A contains the orthographic projection of B" means that the boundary of the orthographic projection of B falls within the boundary range of the orthographic projection of A, or the boundary of the orthographic projection of A overlaps with the boundary of the orthographic projection of B.

[0069] The manufacturing process of the display device may include the following steps:

[0070] (11) Forming a conductive layer pattern. Forming the conductive layer pattern may include: depositing a conductive film on one side of the substrate, and patterning the conductive film using a patterning process to form the conductive layer pattern. For example, the conductive layer may include a plurality of first electrodes and a plurality of connecting lines.

[0071] (12) Cleaning and drying the substrate. Cleaning and drying the substrate may include: using deionized water to clean the substrate 10 formed with the aforementioned pattern, and then using a drying device 60 to bake the cleaned substrate 10 at a temperature of 110 degrees Celsius for 45 seconds, such as Figure 5A shown.

[0072] (13) Modifying the substrate. Modifying the substrate may include: using a spraying device 70 to spray a volatile gas such as hexamethyldisilane (HMDS) on the surface of the substrate 10 formed with the aforementioned pattern (conductive layer) for 25 seconds, such as Figure 5B shown.

[0073] Currently, during the display substrate manufacturing process, plasma surface treatment is typically performed on the substrate before applying protective adhesive. Plasma surface treatment can remove impurities and contaminants from the substrate surface through chemical reactions, but it can also exacerbate oxidation of metal traces. Currently, metal traces are typically made of metal elements such as titanium and copper. The titanium oxide and copper oxide generated by oxidation are highly hydrophilic. After absorbing moisture from the air, polar molecules such as hydrogen peroxide (OH) are formed on the surface. The resin component in the encapsulation adhesive is a non-polar molecule, which reduces the bonding between the two, resulting in poor water and oxygen resistance of the display substrate.

[0074] The embodiments of the present disclosure propose a modification treatment of the substrate: the surface of the substrate 10 formed with the aforementioned pattern is sprayed with a volatile gas such as hexamethyldisilane (HMDS). The spraying time ranges from 20 seconds to 30 seconds, and for example, it can be 25 seconds. On the one hand, HMDS reacts with OH adsorbed on the surface of the substrate to form OSi(CH3)3, modifying the original relatively polar OH to non-polar, which can enhance the adhesion between the substrate and the subsequently formed protective layer. On the other hand, HMDS combines with water in the air to generate NH3. Some metal oxides react with NH3 and water to form easily sublimable ammonium acid substances, which can reduce the degree of oxidation on the substrate surface and reduce the polarity of the substrate surface, thereby enhancing the adhesion between the substrate and the subsequently formed protective layer.

[0075] (14) Performing a cleaning process. The cleaning process may include: using a cleaning device 80 to clean the substrate 10 formed with the aforementioned pattern using an inert gas such as nitrogen for 25 seconds, such as Figure 5C shown.

[0076] (15) Forming a first protective sublayer. Forming the first protective sublayer may include: coating the first protective sublayer 12-1 on one side of the substrate 10 formed with the aforementioned pattern using a coating device 90, such as Figure 5D As shown, in the first direction X, at least a portion of the orthographic projection of the surface of at least one connecting line 111 away from the substrate 10 on the plane where the display substrate is located can be located within the orthographic projection of the first protective sublayer 12-1 on the plane where the display substrate is located. For example, in the first direction X, the orthographic projection of the surface of the connecting line 111 away from the substrate 10 on the plane where the display substrate is located can be located within the orthographic projection of the first protective sublayer 12-1 on the plane where the display substrate is located.

[0077] like Figure 5DAs shown, the first protective sublayer 12-1 has a first side 12A and a second side 12B that are relatively arranged. The first side 12A is closer to the substrate 10 than the second side 12B, and the flatness of the second side 12B is better than the flatness of the first side 12A, which can prevent water and oxygen from invading the display substrate from the edge of the connecting line 111.

[0078] During the development and verification of the finished product, the inventors of this application discovered that the molecular weight distribution of the first protective sublayer material has a significant impact on the adhesion generated between the material and the substrate. Resins with a lower molecular weight have a better wetting effect on the substrate, and during the baking process under the same conditions, resins with a lower molecular weight can achieve close contact with the substrate molecules through thermal Brownian motion, and have strong adhesion to the substrate. However, resins with a lower molecular weight have weak cohesion, while resins with a higher molecular weight have strong cohesion. Resins with a higher molecular weight have better strength and density than resins with a lower molecular weight. However, during the baking process under the same conditions, thermal Brownian motion cannot bring the resin molecules with a higher molecular weight into good contact with the substrate, resulting in weak van der Waals forces and poor adhesion between the formed film layer and the substrate.

[0079] (16) Forming a second protective sublayer. Forming the second protective sublayer may include: coating the second protective sublayer 12-2 on one side of the substrate 10 formed with the aforementioned pattern using a coating device 90, such as Figure 5E As shown, the orthographic projection of the first protective sublayer 12 - 1 on the plane where the display substrate is located can be located within the orthographic projection of the second protective sublayer 12 - 2 on the plane where the display substrate is located.

[0080] The manufacturing process of the display device may further include the following steps:

[0081] (21) Bind and connect with external circuits, such as Figure 6A As shown, for example, the external circuit may be a flexible circuit board 50 , etc., and the flexible circuit board 50 may be electrically connected to the second end of the connecting line 111 .

[0082] (22) Forming a protective layer. Coat the side of the external circuit away from the substrate 10 with encapsulation glue to form a protective layer 30, such as Figure 6B As shown. The material of the protective layer 30 can be tuffy glue. The protective layer 30 can prevent water and oxygen from invading the interior of the display substrate from the edge of the protective layer 12 near the flexible circuit board 50, thereby improving the reliability of the display substrate.

[0083] A method for preparing a display substrate, comprising:

[0084] forming a conductive layer on one side of the substrate, the conductive layer comprising a plurality of connecting lines, the plurality of connecting lines being arranged at intervals along a first direction and extending along a second direction, the first direction intersecting the second direction;

[0085] A protective layer is formed on the side of the conductive layer away from the substrate, and in the first direction, the orthographic projections of the multiple connecting lines on the plane where the display substrate is located are located within the orthographic projection of the protective layer on the plane where the display substrate is located; the protective layer includes at least two protective sublayers, and the molecular weights of materials of at least two of the protective sublayers are different, and the molecular weight of the material of the protective sublayer close to the substrate is smaller than the molecular weight of the material of the protective sublayer adjacent to it.

[0086] In an exemplary embodiment, forming a protective layer on a side of the conductive layer away from the substrate includes:

[0087] forming a first protective sublayer on a side of the conductive layer away from the substrate;

[0088] forming a second protective sublayer on a side of the first protective sublayer away from the substrate;

[0089] The viscosity of the first protective sub-layer is less than the viscosity of the second protective sub-layer.

[0090] The first protective sublayer can be used to completely cover the connecting wires, thereby preventing water and oxygen from corroding the connecting wires and other external circuits of the display substrate. The second protective sublayer can ensure that the overall protective layer has high strength. The thickness of the first protective sublayer is set to be smaller than that of the second protective sublayer, thereby achieving a lightweight and thin design of the protective layer while ensuring that the protective layer meets the design performance parameters.

[0091] In an exemplary embodiment, the orthographic projection of the edge of the connecting line extending along the second direction on the plane where the display substrate is located can be located within the orthographic projection of the first protective sublayer on the plane where the display substrate is located, and the first protective sublayer contacts at least a portion of the surface of the connecting line away from the substrate.

[0092] In an exemplary embodiment, before forming the protective layer on the side of the conductive layer away from the substrate, the preparation method further includes:

[0093] The substrate on which the conductive layer is formed is subjected to a modification process.

[0094] In an exemplary embodiment, the modifying treatment of the substrate having the conductive layer formed thereon includes:

[0095] Hexamethyldisilane gas is used to spray the surface of the substrate on which the conductive layer is formed.

[0096] In an exemplary embodiment, the spraying time ranges from 20 seconds to 30 seconds.

[0097] Figure 7 FIG. 1 is a structural diagram of a spliced ​​display device according to an embodiment of the present disclosure, Figure 7 As shown, the spliced ​​display device may include at least two display devices 300 described in any of the above embodiments, such as Figure 7 As shown, the spliced ​​display device may include nine display devices 300. The spliced ​​display device may be any product or component with a display function, such as an electronic paper, a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, a wearable display device, or the like.

[0098] Although the embodiments disclosed herein are as described above, the contents described are merely embodiments for facilitating understanding of the present invention and are not intended to limit the present invention. It should be noted that the above embodiments or implementations are merely illustrative and not restrictive. Therefore, the present disclosure is not limited to the contents specifically shown and described herein. Various modifications, substitutions, or omissions may be made to the forms and details of the implementations without departing from the scope of the present disclosure.

Claims

1. A display substrate, characterized in that: The device comprises a substrate, a conductive layer located on one side of the substrate, and a protective layer located on a side of the conductive layer away from the substrate; the conductive layer comprises a plurality of connecting lines, the plurality of connecting lines are arranged at intervals along a first direction and extend along a second direction, and the first direction intersects the second direction; in the first direction, the orthographic projections of the plurality of connecting lines on the plane where the display substrate is located are located within the orthographic projection of the protective layer on the plane where the display substrate is located; The protective layer comprises at least two protective sublayers, the molecular weights of materials of at least two protective sublayers are different, and the molecular weight of the material of the protective sublayer close to the substrate is smaller than the molecular weight of the material of the protective sublayer adjacent thereto.

2. The display substrate according to claim 1, wherein: The material of the protective sublayer includes at least a thermosetting resin; the at least two protective sublayers include a first protective sublayer and a second protective sublayer, and the first protective sublayer is closer to the substrate than the second protective sublayer, and the viscosity of the first protective sublayer is less than that of the second protective sublayer.

3. The display substrate according to claim 1, wherein: The at least two protective sublayers include a first protective sublayer and a second protective sublayer, and the first protective sublayer is closer to the substrate than the second protective sublayer; Wherein, the thickness of the first protective sublayer is smaller than the thickness of the second protective sublayer.

4. The display substrate according to claim 3, wherein: The thickness of the first protective sublayer ranges from 1.0 micrometer to 2.5 micrometers; the thickness of the second protective sublayer ranges from 8.0 micrometers to 30 micrometers.

5. The display substrate according to claim 1, wherein: The at least two protective sublayers include a first protective sublayer and a second protective sublayer, and the first protective sublayer is closer to the substrate than the second protective sublayer; The orthographic projection of the edge of the connecting line extending along the second direction on the plane where the display substrate is located is located within the orthographic projection of the first protective sublayer on the plane where the display substrate is located, and the first protective sublayer contacts at least a portion of the surface of the connecting line away from the substrate.

6. A method for preparing a display substrate, characterized in that: include: A conductive layer is formed on one side of the substrate, wherein the conductive layer includes a plurality of connection lines, the plurality of connection lines are arranged at intervals along a first direction and extend along a second direction, and the first direction intersects the second direction; A protective layer is formed on a side of the conductive layer away from the substrate, and in the first direction, the orthographic projections of the multiple connecting lines on the plane where the display substrate is located are located within the orthographic projection of the protective layer on the plane where the display substrate is located; the protective layer includes at least two protective sublayers, and the molecular weights of materials of at least two of the protective sublayers are different, and the molecular weight of the material of the protective sublayer close to the substrate is smaller than the molecular weight of the material of the protective sublayer adjacent thereto.

7. The method for preparing a display substrate according to claim 6, wherein: The forming of a protective layer on a side of the conductive layer away from the substrate comprises: forming a first protective sublayer on a side of the conductive layer away from the substrate; forming a second protective sublayer on a side of the first protective sublayer away from the substrate; Wherein, the viscosity of the first protective sub-layer is less than the viscosity of the second protective sub-layer.

8. The method for preparing a display substrate according to claim 6, wherein: Before forming the protective layer on the side of the conductive layer away from the substrate, the preparation method further comprises: The substrate on which the conductive layer is formed is subjected to a modification process.

9. The method for preparing a display substrate according to claim 8, wherein: The modifying treatment of the substrate having the conductive layer formed thereon comprises: The surface of the substrate on which the conductive layer is formed is sprayed with hexamethyldisilane gas.

10. The method for preparing a display substrate according to claim 9, wherein: The spraying time ranges from 20 seconds to 30 seconds.

Images