Display substrate, manufacturing method thereof and display device

Abstract

The embodiment of the present invention discloses a display substrate, a manufacturing method thereof and a display device. By arranging a flat layer with a relatively flat surface facing the second metal layer between the first metal layer and the second metal layer, the second metal layer deposited on the flat layer is also relatively flat. When the second metal layer is subsequently patterned by a photoresist process to form a plurality of second metal traces, the photoresist thickness of the fan-shaped area can be ensured to be uniform, and the manufacturing accuracy of the second metal traces of the second metal layer can be improved, so that the second metal traces with the same width and spacing as the first metal traces can be formed. In the scheme of the present invention, the etching resolution of the metal traces in the fan-shaped area corresponding to the first metal layer and the second metal layer can be the same, which can reduce the wiring space of the fan-shaped area and further realize a narrow frame.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a display substrate, a manufacturing method thereof and a display device. Background Art

[0002] At present, people have higher and higher requirements for the full display of display products, and full display and narrow borders have become the trend of display products.

[0003] The display panel usually includes a display area and a fanout area located outside the display area for wiring. The width of the fanout area directly determines the width of the display panel frame. In order to reduce the width of the fanout area, the industry has developed a double-layer metal wiring method, in which each metal layer is provided with multiple signal lines. Due to the influence of the process, the spacing between the signal lines of the top metal layer is greater than the spacing between the signal lines of the bottom metal layer. Therefore, the spacing between the signal lines of the top metal layer determines the width of the fanout area, further limiting the narrow frame design of the display panel. Summary of the invention

[0004] A display substrate provided by an embodiment of the present invention includes a base substrate, wherein the base substrate has a fan-shaped area;

[0005] The display substrate comprises a first metal layer, a flat layer, and a second metal layer sequentially formed on the base substrate; the orthographic projection of the flat layer on the base substrate at least covers the orthographic projection of the fan-shaped area on the base substrate; in the fan-shaped area, the surface of the flat layer farthest from the base substrate has a highest point with the largest distance to the horizontal plane where the base substrate is located and a lowest point with the smallest distance to the horizontal plane where the base substrate is located, and the difference in distance between the highest point and the lowest point to the horizontal plane where the base substrate is located is less than or equal to 1000 angstroms;

[0006] The first metal layer includes a plurality of first metal traces located in the fan-shaped area, the second metal layer includes a plurality of second metal traces located in the fan-shaped area, and the orthographic projection of the first metal traces on the substrate at least partially overlaps with the orthographic projection of the second metal traces on the substrate.

[0007] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the distances from the highest point and the lowest point to the horizontal plane where the base substrate is located are equal.

[0008] Optionally, in the above-mentioned display substrate provided by the embodiment of the present invention, it further includes a first insulating layer located between the first metal layer and the planar layer, and the orthographic projection of the first insulating layer on the base substrate covers the base substrate.

[0009] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, it also includes a second insulating layer located between the flat layer and the second metal layer, and the orthographic projection of the second insulating layer on the base substrate at least covers the orthographic projection of the fan-shaped area on the base substrate.

[0010] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the thickness of the planar layer is greater than the thickness of the first metal layer.

[0011] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the width of the first metal wiring is the same as the width of the second metal wiring, and the width of the gap between adjacent first metal wirings is the same as the width of the gap between adjacent second metal wirings.

[0012] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the orthographic projection of the first metal wiring on the base substrate completely overlaps with the orthographic projection of the second metal wiring on the base substrate.

[0013] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the base substrate further has a display area located on one side of the fan-shaped area, the first metal layer includes a gate located in the display area, and the second metal layer includes a source and a drain located in the display area;

[0014] The orthographic projection of the planar layer on the base substrate also covers the orthographic projection of the display area on the base substrate, and the orthographic projection of the second insulating layer on the base substrate also covers the orthographic projection of the display area on the base substrate;

[0015] The display substrate further comprises: a first transparent conductive layer located between the second insulating layer and the second metal layer, a passivation layer located on a side of the second metal layer away from the base substrate, and a second transparent conductive layer located on a side of the passivation layer away from the base substrate;

[0016] The first transparent conductive layer is electrically connected to the drain electrode, the second transparent conductive layer includes a plurality of transparent signal lines located in the display area, and an orthographic projection of the first transparent conductive layer on the base substrate overlaps with an orthographic projection of the plurality of transparent signal lines on the base substrate.

[0017] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the base substrate further has a via area located between the fan-shaped area and the display area, the first metal layer includes a first switching electrode located in the via area, and the second metal layer includes a second switching electrode located in the via area;

[0018] The orthographic projection of the flat layer on the base substrate also covers a portion of the orthographic projection of the via area on the base substrate, and the orthographic projection of the second insulating layer on the base substrate also covers a portion of the orthographic projection of the via area on the base substrate;

[0019] The second transparent conductive layer includes a plurality of transparent traces located in the via region;

[0020] Part of the transparent wiring is electrically connected to the first transfer electrode through a via hole that sequentially penetrates the passivation layer, the second insulating layer, the planar layer, and the first insulating layer;

[0021] Part of the transparent wiring is electrically connected to the second transfer electrode through a via hole penetrating the passivation layer.

[0022] Accordingly, an embodiment of the present invention further provides a method for manufacturing a display substrate, comprising:

[0023] Providing a substrate; the substrate has a fan-shaped area;

[0024] Forming a first metal layer on the substrate; wherein the first metal layer includes a plurality of first metal traces located in the fan-shaped area;

[0025] A flat layer is formed on the side of the first metal layer facing away from the substrate; wherein the orthographic projection of the flat layer on the substrate at least covers the orthographic projection of the fan-shaped area on the substrate; in the fan-shaped area, the surface of the flat layer farthest from the substrate has a highest point with the largest distance to the horizontal plane where the substrate is located and a lowest point with the smallest distance to the horizontal plane where the substrate is located, and the difference in distance between the highest point and the lowest point to the horizontal plane where the substrate is located is less than or equal to 1000 angstroms;

[0026] A second metal layer is formed on the side of the flat layer away from the base substrate; wherein the second metal layer includes a plurality of second metal traces located in the fan-shaped area, and the orthographic projection of the first metal trace on the base substrate at least partially overlaps with the orthographic projection of the second metal trace on the base substrate.

[0027] Optionally, in the above manufacturing method provided by the embodiment of the present invention, before forming the flat layer on the side of the first metal layer away from the base substrate, the method further comprises:

[0028] A first insulating layer is formed between the first metal layer and the planar layer; the orthographic projection of the first insulating layer on the base substrate covers the base substrate.

[0029] Optionally, in the above manufacturing method provided by an embodiment of the present invention, the forming of the flat layer on the side of the first metal layer away from the base substrate is specifically:

[0030] A flat layer having a thickness greater than that of the first metal layer is formed on a side of the first metal layer away from the base substrate.

[0031] Optionally, in the above manufacturing method provided by the embodiment of the present invention, after forming the planar layer and before forming the second metal layer, it further includes:

[0032] A second insulating layer is formed between the planar layer and the second metal layer; wherein the orthographic projection of the second insulating layer on the base substrate at least covers the orthographic projection of the fan-shaped area on the base substrate.

[0033] Optionally, in the above manufacturing method provided by the embodiment of the present invention, forming the plurality of first metal traces specifically includes:

[0034] Coating a first photoresist layer on a side of the first metal layer facing away from the substrate;

[0035] Exposing and developing the first photoresist layer to form the plurality of first metal traces;

[0036] Forming the plurality of second metal traces specifically includes:

[0037] Coating a second photoresist layer on a side of the second metal layer facing away from the substrate;

[0038] The second photoresist layer is exposed and developed to form the plurality of second metal wirings corresponding to the plurality of first metal wirings.

[0039] Correspondingly, an embodiment of the present invention further provides a display device, comprising the above-mentioned display substrate provided by an embodiment of the present invention.

[0040] The beneficial effects of the embodiments of the present invention are as follows:

[0041] A display substrate, a manufacturing method thereof and a display device provided by an embodiment of the present invention, wherein a flat layer is arranged between a first metal layer and a second metal layer, and the orthographic projection of the flat layer on the substrate at least covers the orthographic projection of the fan-shaped area on the substrate. In the fan-shaped area, the surface of the flat layer farthest from the substrate has a highest point with the largest distance to the horizontal plane where the substrate is located and a lowest point with the smallest distance to the horizontal plane where the substrate is located, and the difference in distance between the highest point and the lowest point to the horizontal plane where the substrate is located is less than or equal to 1000 angstroms; thus, the surface of the flat layer facing the second metal layer is relatively flat, so the second metal layer deposited on the flat layer is also relatively flat, and when the second metal layer is subsequently patterned by a photoresist process to form a plurality of second metal traces, the photoresist thickness of the fan-shaped area can be ensured to be uniform, and the manufacturing accuracy of the second metal traces of the second metal layer can be improved, so that the second metal traces with the same width and spacing as the first metal traces can be formed. Therefore, in the scheme of the present invention, the etching resolution of the metal traces in the fan-shaped area corresponding to the first metal layer and the second metal layer can be the same, so that the wiring space of the fan-shaped area can be reduced, and a narrow frame can be further achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of a display substrate in the related art;

[0043] Figure 2 A schematic top view of a display substrate provided by an embodiment of the present invention;

[0044] Figure 3 for Figure 2 A schematic cross-sectional view along the CC' direction;

[0045] Figure 4 for Figure 2 Another cross-sectional schematic diagram along the CC' direction;

[0046] Figure 5 for Figure 2 Another cross-sectional schematic diagram along the CC' direction;

[0047] Figure 6 A schematic flow chart of a method for manufacturing a display substrate provided by an embodiment of the present invention;

[0048] Figure 7 A schematic flow chart of another method for manufacturing a display substrate provided by an embodiment of the present invention;

[0049] Figure 8 A schematic flow chart of another method for manufacturing a display substrate provided by an embodiment of the present invention;

[0050] Fig. 9 A schematic flow chart of another method for manufacturing a display substrate provided by an embodiment of the present invention;

[0051] Fig.10 A schematic flow chart of another method for manufacturing a display substrate provided by an embodiment of the present invention;

[0052] Figures 11A-11F for Figure 5 A schematic diagram of the structure of the corresponding display substrate after executing each manufacturing step;

[0053] Fig.12 A schematic structural diagram of a display device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. And in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0055] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "include" or "comprise" and the like used in the present invention mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. The words "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Inside", "outside", "upper", "lower", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0056] It should be noted that the sizes and shapes of the figures in the accompanying drawings do not reflect the actual proportions, but are only intended to illustrate the content of the present invention. The same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0057] With the development of display technology, display products need to achieve perfect visual effects with narrow bezel design. The metal traces of the lower bezel are peripheral circuits that connect the effective display area of ​​the display panel and the driver chip, called fanout signal lines. Therefore, it is necessary to reduce the line width (Line) and line spacing (Space) of the fanout area to reduce the fanout area and achieve a narrow bezel. The sum of the line width and line spacing is called the fanout pitch.

[0058] The existing fan-shaped area wiring design uses two layers of metal overlap to make the fan-shaped area to reduce the fan-shaped area signal line arrangement space, such as Figure 1 As shown, it includes a base substrate 1', a first metal layer 2' and a second metal layer 3' stacked on the base substrate 1', an insulating layer 4' is provided between the first metal layer 2' and the second metal layer 3', and the first metal layer 2' is exposed, developed and etched by a photoresist process to form a plurality of first metal traces 21'. However, when making metal traces on the second metal layer 3', a photoresist layer 5' is firstly coated on the second metal layer 3'. Due to the unevenness of the insulating layer 4', the second metal layer 3' is also uneven, so the thickness of the photoresist layer 5' coated on the second metal layer 3' is uneven, which makes the exposure uniformity worse, affecting the manufacturing accuracy of the second metal traces of the second metal layer 3'. For example, in actual production, while ensuring that the metal routing does not have open and short defects, the first metal routing 21' of the first metal layer 2' can be made into a line of 2.5μm, a space of 2.5μm, and a fanout pitch of 5.0μm. However, due to the influence of the process, the second metal layer 3' can only make the space of 3.0μm and the fanout pitch of 5.5μm. If the fanout pitch of the second metal layer 3' is to be the same as the fanout pitch of the first metal layer 2' to further realize the narrow frame design, the line of the second metal layer 3' needs to be made into 2.0um, and the risk of line open is relatively large, so the second metal layer 3' needs to change the design pitch to 5.5um. Therefore, the fanout pitch size is limited by the resolution of the second metal layer 3' and can only be made into 5.5μm, which affects the narrow frame design of the display panel.

[0059] In view of this, an embodiment of the present invention provides a display substrate, such as Figure 2 and Figure 3 As shown, Figure 2 Schematic diagram showing a top view of a substrate. Figure 3 for Figure 2 The cross-sectional schematic diagram along the CC' direction in FIG. 1 shows a display substrate comprising: a base substrate 1, the base substrate 1 having a fan-shaped area B1;

[0060] The display substrate comprises a first metal layer 2, a flat layer 6 and a second metal layer 3 which are sequentially formed on a base substrate 1; the orthographic projection of the flat layer 6 on the base substrate 1 at least covers the orthographic projection of the sector area B1 on the base substrate 1; in the sector area B1, the surface of the flat layer 6 farthest from the base substrate 1 has a highest point with the largest distance to the horizontal plane where the base substrate 1 is located and a lowest point with the smallest distance to the horizontal plane where the base substrate 1 is located, and the difference in distance between the highest point and the lowest point to the horizontal plane where the base substrate 1 is located is less than or equal to 1000 angstroms, so as to ensure the flatness of the surface of the flat layer 6 farthest from the base substrate 1;

[0061] The first metal layer 2 includes a plurality of first metal traces 21 located in the fan-shaped area B1, and the second metal layer 3 includes a plurality of second metal traces 31 located in the fan-shaped area B1, and the orthographic projection of the first metal trace 21 on the substrate 1 at least partially overlaps with the orthographic projection of the second metal trace 31 on the substrate 1; specifically, Figure 2 Only the plurality of second metal wirings 31 located in the sector area B1 are illustrated, and the plurality of first metal wirings 21 located in the sector area B1 are located below the second metal wirings 31 .

[0062] The above-mentioned display substrate provided by the embodiment of the present invention is provided with a flat layer 6 between the first metal layer 2 and the second metal layer 3, and the orthographic projection of the flat layer 6 on the base substrate 1 at least covers the orthographic projection of the sector area B1 on the base substrate 1. In the sector area B1, the surface of the flat layer 6 farthest from the base substrate 1 has a highest point with the largest distance to the horizontal plane where the base substrate 1 is located and a lowest point with the smallest distance to the horizontal plane where the base substrate 1 is located, and the difference in distance between the highest point and the lowest point to the horizontal plane where the base substrate 1 is located is less than or equal to 1000 angstroms; in this way, the surface of the flat layer 6 facing the second metal layer 3 is relatively flat, so the second metal layer 3 deposited on the flat layer 6 is also relatively flat. When the second metal layer 3 is subsequently patterned by a photoresist process to form a plurality of second metal traces 31, the photoresist thickness of the sector area B1 can be ensured to be uniform, and the manufacturing accuracy of the second metal traces 31 of the second metal layer 3 can be improved, so that the second metal traces 31 with the same width and spacing as the first metal traces 21 can be formed. Therefore, in the solution of the present invention, the metal routing etching resolution of the sector area B1 corresponding to the first metal layer 2 and the second metal layer 3 can be the same, thereby reducing the wiring space of the sector area B1 and further achieving a narrow frame.

[0063] In a preferred embodiment, the distances from the highest point and the lowest point on the surface of the flat layer farthest from the substrate to the horizontal plane where the substrate is located are equal. Equal means that the difference between the distances from the highest point and the lowest point to the horizontal plane where the substrate is located is within the error range, for example, the difference between the distance from the highest point to the horizontal plane where the substrate is located and the distance from the lowest point to the horizontal plane where the substrate is located is less than or equal to 100 angstroms.

[0064] In a specific implementation, the material of the planar layer may be an organic resin material, such as polyimide, but is not limited thereto.

[0065] In a specific implementation, since the material of the planar layer is generally an organic material, the adhesion between the organic material and the metal layer is poor, and the film layer manufactured subsequently is easy to separate from the base substrate, in the above-mentioned display substrate provided in an embodiment of the present invention, Figure 4 As shown, the first insulating layer 4 is also included between the first metal layer 2 and the flat layer 6, and the orthographic projection of the first insulating layer 4 on the base substrate 1 covers the base substrate 1. Specifically, the first insulating layer 4 can be made of silicon nitride SiNx, silicon oxide SiOx or a composite layer of SiNx / SiOx, and the first insulating layer 4 can improve the adhesion between the subsequently manufactured film layer and the base substrate 1.

[0066] In a specific implementation, on the one hand, the adhesion between the planar layer and the metal layer is poor, and on the other hand, particles exist in the planar layer of the organic material, which affects the device performance. Therefore, in the above-mentioned display substrate provided in the embodiment of the present invention, Figure 5 As shown, it also includes a second insulating layer 7 located between the flat layer 6 and the second metal layer 3, and the orthographic projection of the second insulating layer 7 on the substrate 1 at least covers the orthographic projection of the sector area B1 on the substrate 1. Specifically, the second insulating layer 7 can be made of silicon nitride SiNx, silicon oxide SiOx or a composite layer of SiNx / SiOx.

[0067] In a specific implementation, in order to further ensure the flatness of the surface of the flat layer, in the above-mentioned display substrate provided by the embodiment of the present invention, as Figure 3-Figure 5 As shown, the thickness of the planar layer 6 needs to be greater than the thickness of the first metal layer 2 . The specific thickness of the planar layer 6 is selected according to actual needs and is not limited thereto.

[0068] In a specific implementation, since a flat layer with good flatness is provided between the first metal layer and the second metal layer, when the second metal wiring is made in the second metal layer by using a photoresist exposure, development and etching process, the second metal wiring with the same width and spacing as the first metal wiring can be formed. Therefore, in the above-mentioned display substrate provided in an embodiment of the present invention, Figure 3-Figure 5 As shown, the width d1 of the first metal trace 21 is the same as the width d2 of the second metal trace 31, which can be 2.5 μm; the gap width w1 between adjacent first metal traces 21 is the same as the gap width w2 between adjacent second metal traces 31, which can be 2.5 μm. Therefore, the metal trace etching resolution of the sector area B1 corresponding to the first metal layer 2 and the second metal layer 3 can be the same, thereby reducing the wiring space of the sector area B1 and further realizing a narrow frame.

[0069] In a specific implementation, in the above-mentioned display substrate provided in an embodiment of the present invention, as Figure 3-Figure 5 As shown, the orthographic projection of the first metal trace 21 on the base substrate 1 completely overlaps with the orthographic projection of the second metal trace 31 on the base substrate 1. That is, the center lines of the first metal trace 21 and the second metal trace 31 coincide with each other in the thickness direction of the display substrate. Of course, it is a preferred solution that the orthographic projections of the first metal trace 21 and the second metal trace 31 on the base substrate 1 completely overlap. In other embodiments, the effect of reducing the border can be achieved as long as the orthographic projections are partially overlapped. It is only when the orthographic projections are completely overlapped that the effect of shortening the narrow border is optimal.

[0070] In specific implementation, the display substrate provided in the embodiment of the present invention may be a display substrate of an OLED display screen, or may be a display substrate of an LCD display screen. The embodiment of the present invention is described by taking the display substrate as an example. Figure 5 Taking the structure shown in FIG. 1 as an example, the film layer structure in other areas of the display substrate is described in detail. Figure 3 and Figure 4 Zhongyu Figure 5 The same film structure as in Figure 5 's hint.

[0071] In a specific implementation, in the above-mentioned display substrate provided in an embodiment of the present invention, as Figure 2 and Figure 5 As shown, the base substrate 1 also has a display area AA located on one side of the sector area B1, the first metal layer 2 includes a gate 22 located in the display area AA, and the second metal layer 3 includes a source 32 and a drain 33 located in the display area AA; specifically, the display substrate also includes an active layer 11 located between the second insulating layer 7 and the source 32 and the drain 33, and the gate 22, the active layer 11, the source 32 and the drain 33 constitute a driving transistor in the display area AA;

[0072] In order to improve the performance of the device manufactured in the display area AA, the orthographic projection of the flat layer 6 provided in the embodiment of the present invention on the base substrate 1 also covers the orthographic projection of the display area AA on the base substrate 1, so as to improve the flatness of the display area AA. The conditions satisfied by the surface flatness of the flat layer 6 in the display area AA can refer to the description of the fan-shaped area B1; the orthographic projection of the second insulating layer 7 on the base substrate 1 also covers the orthographic projection of the display area AA on the base substrate 1, so as to solve the problem of particles appearing in the display area AA;

[0073] The display substrate further includes: a first transparent conductive layer 8 located between the second insulating layer 7 and the second metal layer 3, a passivation layer 9 located on the side of the second metal layer 3 away from the base substrate 1, and a second transparent conductive layer 10 located on the side of the passivation layer 9 away from the base substrate 1; specifically, since the display substrate is an LCD display screen display substrate as an example, the first transparent conductive layer 8 can be a pixel electrode layer, and the second transparent conductive layer 10 can be a common electrode layer; the materials of the first transparent conductive layer 8 and the second transparent conductive layer 10 can be transparent conductive materials such as ITO;

[0074] The first transparent conductive layer 8 is electrically connected to the drain electrode 33, the second transparent conductive layer 10 includes a plurality of transparent signal lines 101 located in the display area AA, and the orthographic projection of the first transparent conductive layer 8 on the base substrate 1 overlaps with the orthographic projection of the plurality of transparent signal lines 101 on the base substrate 1; specifically, when the LCD display screen is displaying, a common electrode signal is loaded to the common electrode through the transparent signal line 101, and a driving signal is loaded to the pixel electrode through the driving transistor, and the liquid crystal of the LCD display screen is driven to flip by the electric field formed between the common electrode and the pixel electrode, and light passes through the liquid crystal layer to realize display.

[0075] In a specific implementation, a plurality of transparent signal lines of the second transparent conductive layer need to be led out to the sector-shaped areas corresponding to the first metal layer and the second metal layer through via holes to realize electrical connection with the peripheral driving chip (IC). Since the second transparent conductive layer and the first metal layer and the second metal layer are located in different layers, they need to be transferred to the sector-shaped areas corresponding to the first metal layer and the second metal layer through via holes. Therefore, in the above-mentioned display substrate provided in an embodiment of the present invention, Figure 2 and Figure 5 As shown, the base substrate 1 also has a via area B2 located between the fan-shaped area B1 and the display area AA, the first metal layer 2 includes a first switching electrode 23 located in the via area B2, and the second metal layer 3 includes a second switching electrode 34 located in the via area B2;

[0076] In order to further improve the flatness of the film layer in the via area B2, the orthographic projection of the flat layer 6 provided in the embodiment of the present invention on the base substrate 1 also covers a part of the orthographic projection of the via area B2 on the base substrate 1. The conditions for the surface flatness of the flat layer 6 in the via area B2 can refer to the description of the fan-shaped area B1. The orthographic projection of the second insulating layer 7 on the base substrate 1 also covers a part of the orthographic projection of the via area B2 on the base substrate 1.

[0077] The second transparent conductive layer 10 includes a plurality of transparent traces 102 located in the via area B2;

[0078] Part of the transparent wiring 102 is electrically connected to the first transfer electrode 23 through the via V1 that passes through the passivation layer 9, the second insulating layer 7, the flat layer 6 and the first insulating layer 4 in sequence, and part of the transparent wiring 102 is electrically connected to the second transfer electrode 34 through the via V2 that passes through the passivation layer 9, so that the transparent wiring 102 of the second transparent conductive layer 10 is respectively led out to the fan-shaped area B1 corresponding to the first metal layer 2 and the second metal layer 3, thereby realizing the design of a double-layer metal wiring in the fan-shaped area B1, which is conducive to realizing a narrow frame design.

[0079] It should be noted that Figure 2 The display area AA in the figure only illustrates part of the transparent signal line 101. Of course, the display area AA also includes other signal lines such as gate lines, data lines, power lines, etc. These signal lines are electrically connected to the metal wiring (first metal layer 2 or second metal layer 3) of the fan-shaped area B1 to be electrically connected to the driving chip (IC) to realize the signal transmission function.

[0080] Based on the same inventive concept, the embodiment of the present invention also provides a method for manufacturing a display substrate, such as Figure 6 As shown, including:

[0081] S601, providing a substrate; the substrate has a fan-shaped area;

[0082] S602, forming a first metal layer on the substrate; wherein the first metal layer includes a plurality of first metal traces located in the fan-shaped area;

[0083] S603, forming a flat layer on the side of the first metal layer facing away from the substrate; wherein the orthographic projection of the flat layer on the substrate at least covers the orthographic projection of the fan-shaped area on the substrate; in the fan-shaped area, the surface of the flat layer farthest from the substrate has a highest point with the largest distance to the horizontal plane where the substrate is located and a lowest point with the smallest distance to the horizontal plane where the substrate is located, and the difference in distance between the highest point and the lowest point to the horizontal plane where the substrate is located is less than or equal to 1000 angstroms;

[0084] S604, forming a second metal layer on the side of the flat layer away from the base substrate; wherein the second metal layer includes a plurality of second metal traces located in the fan-shaped area, and the orthographic projection of the first metal trace on the base substrate at least partially overlaps with the orthographic projection of the second metal trace on the base substrate.

[0085] The manufacturing method of the display substrate provided by the embodiment of the present invention is as follows: a flat layer is manufactured between the first metal layer and the second metal layer, and the orthographic projection of the flat layer on the substrate at least covers the orthographic projection of the fan-shaped area on the substrate, and the surface of the flat layer away from the substrate includes the highest point and the lowest point, and the difference between the distance from the highest point to the horizontal plane where the substrate is located and the distance from the lowest point to the horizontal plane where the substrate is located is less than or equal to 1000 angstroms; in this way, the surface of the flat layer facing the second metal layer is relatively flat, so the second metal layer deposited on the flat layer is also relatively flat, and when the second metal layer is subsequently patterned by a photoresist process to form a plurality of second metal traces, the uniform thickness of the photoresist in the fan-shaped area can be ensured, and the manufacturing accuracy of the second metal traces of the second metal layer can be improved, so that the second metal traces with the same width and spacing as the first metal traces can be formed. Therefore, in the scheme of the present invention, the etching resolution of the metal traces in the fan-shaped area corresponding to the first metal layer and the second metal layer can be the same, so that the wiring space of the fan-shaped area can be reduced, and a narrow frame can be further achieved.

[0086] In specific implementation, since the material of the flat layer is generally an organic material, the adhesion between the organic material and the metal layer is poor, and the film layer manufactured subsequently is easy to separate from the substrate. In the above manufacturing method provided in the embodiment of the present invention, Figure 7 As shown, before the first metal layer forms a flat layer on the side facing away from the substrate, the method further includes:

[0087] S602', forming a first insulating layer between the first metal layer and the flat layer; the orthographic projection of the first insulating layer on the substrate covers the substrate. Specifically, the first insulating layer can be made of silicon nitride SiNx, silicon oxide SiOx or a composite layer of SiNx / SiOx, and the first insulating layer can improve the adhesion between the subsequently manufactured film layer and the substrate.

[0088] In a specific implementation, in order to further ensure the flatness of the surface of the flat layer, in the above-mentioned manufacturing method provided in an embodiment of the present invention, a flat layer is formed on the side of the first metal layer away from the base substrate, which can be specifically:

[0089] A flat layer having a thickness greater than that of the first metal layer is formed on the side of the first metal layer away from the substrate. Specifically, the specific thickness of the flat layer is selected according to actual needs and is not limited thereto.

[0090] In a specific implementation, on the one hand, the adhesion between the planar layer and the metal layer is poor, and on the other hand, particles exist in the planar layer of the organic material, which affects the device performance. Therefore, in the above-mentioned display substrate provided in the embodiment of the present invention, Figure 8 As shown, after forming the planar layer and before forming the second metal layer, the method further includes:

[0091] S603', forming a second insulating layer between the flat layer and the second metal layer; wherein the orthographic projection of the second insulating layer on the substrate at least covers the orthographic projection of the sector area on the substrate. Specifically, the second insulating layer can be a composite layer of silicon nitride SiNx, silicon oxide SiOx or SiNx / SiOx, and the second insulating layer can improve the adhesion between the subsequently manufactured film layer and the substrate 1, and solve the problem that the particles in the flat layer affect the device performance.

[0092] In the specific implementation, in the above-mentioned manufacturing method provided in the embodiment of the present invention, if Fig. 9 As shown, forming a plurality of first metal traces may specifically include:

[0093] S901, coating a first photoresist layer on a side of the first metal layer facing away from the substrate;

[0094] S902, exposing and developing the first photoresist layer to form a plurality of first metal traces;

[0095] like Fig.10 As shown, forming a plurality of second metal traces may specifically include:

[0096] S1001, coating a second photoresist layer on a side of the second metal layer facing away from the substrate;

[0097] S1001, exposing and developing the second photoresist layer to form a plurality of second metal wirings corresponding to the plurality of first metal wirings.

[0098] Below Figure 5 Taking the display substrate manufacturing method provided by the embodiment of the present invention as an example, the following is a detailed description:

[0099] (1) A first metal layer 2 is formed on the substrate 1 by a conventional film forming process, a first photoresist layer (not shown) is coated on the side of the first metal layer 2 facing away from the substrate 1, the first photoresist layer is exposed and developed, and the first metal layer 2 is etched to form a gate 22 located in the display area AA, a first transfer electrode 23 located in the via area B2, and a first metal wiring 21 located in the fan-shaped area. The material of the first metal layer 2 can be Al / Mo, and the thickness can be about 3400 angstroms; then, a first insulating layer 4 is deposited on the side of the first metal layer 2 facing away from the substrate 1 by a PECVD chemical vapor deposition process. The material of the first insulating layer 4 can be silicon nitride SiNx, silicon oxide SiOx or a composite layer of SiNx / SiOx, and the thickness of the first insulating layer 4 is about 2000 angstroms; then, a flat layer 6 is formed on the side of the first insulating layer 4 facing away from the substrate by a coating and baking process. The material of the flat layer 6 can be an organic material, and the thickness of the flat layer 6 is about 5000 angstroms, as shown in FIG. Fig.11A As shown;

[0100] (2) A second insulating layer 7 is deposited on the side of the flat layer 6 away from the substrate 1 by using a PECVD chemical vapor deposition process. The material of the second insulating layer 7 can be silicon nitride SiNx, silicon oxide SiOx or a composite layer of SiNx / SiOx. The thickness of the second insulating layer 7 is about 2000 angstroms. Then, an a-Si material is deposited on the side of the second insulating layer 7 away from the substrate 1 by using a PECVD chemical vapor deposition process. The thickness can be about 1800 angstroms. Then, a silicon island pattern of the active layer 11 is formed by exposure, dry etching and stripping processes, as shown in FIG. Fig. 11B As shown;

[0101] (3) A first transparent conductive layer 8 is formed on the second insulating layer 7 by conventional sputtering, photolithography, and etching processes. The material of the first transparent conductive layer 8 may be a transparent conductive material such as ITO. The thickness of the first transparent conductive layer 8 may be about 400 angstroms. Fig. 11C As shown;

[0102] (4) On the basis of step (3), a second metal layer 3 is deposited by sputtering. The material of the second metal layer 3 may be a three-layer metal layer of Mo / Al / Mo. The corresponding thickness of the three-layer metal layer is about 150 / 2000 / 800 angstroms. At this time, the surface of the second metal layer 3 corresponding to the sector B1 is a flat surface. A second photoresist layer 12 is coated on the side of the second metal layer 3 facing away from the substrate 1. The surface of the second photoresist layer 12 is a flat surface. Fig.11D As shown;

[0103] (5) The second photoresist layer 12 is exposed and developed, and the second metal layer 3 is etched to form a source 32 and a drain 33 located in the display area AA, a second transfer electrode 34 located in the via area B2, and a second metal trace 31 located in the fan-shaped area. The material of the second metal layer 2 can be Al / Mo, and the thickness can be about 3400 angstroms. Since the surface of the second metal layer 3 is flat, the exposure resolution of the fan-shaped area B1 is equivalent to that of the first metal layer 2, so that the first metal trace 21 of the first metal layer 2 and the second metal trace 31 of the second metal layer 3 have the same line width and line spacing, as shown in FIG. Fig.11E As shown;

[0104] (6) A PECVD chemical vapor deposition process is used to form a film on the side of the second metal layer 3 away from the substrate 1, and a passivation layer 9 having via holes V1 and V2 in the via hole area B2 is formed by exposure and etching processes. The material of the passivation layer 9 can be SiNx, and the thickness of the passivation layer 9 can be about 6000 angstroms. Fig.11F As shown;

[0105] (7) A second transparent conductive layer 10 is formed on the side of the passivation layer 9 facing away from the base substrate 1 by a sputtering film forming process, and a transparent signal line 101 located in the display area AA and a transparent routing line 102 located in the via area B2 are formed by an exposure and etching process. The material of the second transparent conductive layer 10 can be a transparent conductive material such as ITO, and the thickness of the second transparent conductive layer 10 can be about 700 angstroms, as shown in 5.

[0106] Through the steps (1) to (7), Figure 5 The display substrate is shown.

[0107] In summary, the line width and line spacing of the first metal trace 21 of the first metal layer 2 finally formed by the above scheme of the present invention can be 2.5μm / 2.5μm, and the fanout pitch is 5.0μm; the line width and line spacing of the second metal trace 31 of the second metal layer 3 can be 2.5μm / 2.5μm, and the fanout pitch is 5.0μm; while in the prior art, due to the limitation of the exposure resolution of the second metal layer, the line width and line spacing can only be 2.5μm / 3.0μm, and the fanout pitch is 5.5μm. Therefore, the scheme of the present invention can reduce the wiring space of the fanout area and further realize the narrow frame design.

[0108] In addition, the embodiment of the present invention only needs to form a flat layer between the second metal layers, and the adopted process flow does not need to add a mask, has high compatibility with existing processes, and saves costs.

[0109] Based on the same inventive concept, an embodiment of the present invention further provides a display device, including the display substrate provided by the embodiment of the present invention. The principle of solving the problem by the display device is similar to that of the display substrate, so the implementation of the display device can refer to the implementation of the display substrate, and the repeated parts will not be repeated here.

[0110] In a specific implementation, the display device provided in the embodiment of the present invention may be an organic light emitting display device or a liquid crystal display device, which is not limited herein.

[0111] In a specific implementation, the display device provided in the embodiment of the present invention may be a full-screen display device, or may be a flexible display device, etc., which is not limited here.

[0112] In a specific implementation, the display device provided by the embodiment of the present invention may be as follows: Fig.12The full-screen mobile phone shown. Of course, the display device provided in the embodiment of the present invention can also be any product or component with a display function, such as a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, etc. Other essential components of the display device should be understood by ordinary technicians in the field, and will not be repeated here, nor should they be used as limitations on the present invention.

[0113] A display substrate, a manufacturing method thereof and a display device provided by an embodiment of the present invention, wherein a flat layer is arranged between a first metal layer and a second metal layer, and the orthographic projection of the flat layer on the substrate at least covers the orthographic projection of the fan-shaped area on the substrate. In the fan-shaped area, the surface of the flat layer farthest from the substrate has a highest point with the largest distance to the horizontal plane where the substrate is located and a lowest point with the smallest distance to the horizontal plane where the substrate is located, and the difference in distance between the highest point and the lowest point to the horizontal plane where the substrate is located is less than or equal to 1000 angstroms; thus, the surface of the flat layer facing the second metal layer is relatively flat, so the second metal layer deposited on the flat layer is also relatively flat, and when the second metal layer is subsequently patterned by a photoresist process to form a plurality of second metal traces, the photoresist thickness of the fan-shaped area can be ensured to be uniform, and the manufacturing accuracy of the second metal traces of the second metal layer can be improved, so that the second metal traces with the same width and spacing as the first metal traces can be formed. Therefore, in the scheme of the present invention, the etching resolution of the metal traces in the fan-shaped area corresponding to the first metal layer and the second metal layer can be the same, so that the wiring space of the fan-shaped area can be reduced, and a narrow frame can be further achieved.

[0114] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0115] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A display substrate, characterized in that: A substrate substrate is provided, wherein the substrate substrate has a fan-shaped area; The display substrate comprises a first metal layer, a planar layer, and a second metal layer sequentially formed on the base substrate; The orthographic projection of the flat layer on the substrate at least covers the orthographic projection of the fan-shaped area on the substrate; in the fan-shaped area, the surface of the flat layer farthest from the substrate has a highest point with the largest distance to the horizontal plane where the substrate is located and a lowest point with the smallest distance to the horizontal plane where the substrate is located, and the difference in distance between the highest point and the lowest point and the horizontal plane where the substrate is located is less than or equal to 1000 angstroms; The first metal layer includes a plurality of first metal traces located in the fan-shaped area, the second metal layer includes a plurality of second metal traces located in the fan-shaped area, and the orthographic projection of the first metal traces on the substrate at least partially overlaps with the orthographic projection of the second metal traces on the substrate; The first metal wiring and the second metal wiring are used to connect the effective display area of ​​the display panel and the driving chip.

2. The display substrate according to claim 1, wherein: The distances between the highest point and the lowest point and the horizontal plane where the substrate is located are equal.

3. The display substrate according to claim 1, wherein: It also includes a first insulating layer located between the first metal layer and the planar layer, wherein the orthographic projection of the first insulating layer on the base substrate covers the base substrate.

4. The display substrate according to claim 1, wherein: It also includes a second insulating layer located between the planar layer and the second metal layer, wherein the orthographic projection of the second insulating layer on the substrate at least covers the orthographic projection of the fan-shaped area on the substrate.

5. The display substrate according to claim 1, wherein: The thickness of the planar layer is greater than the thickness of the first metal layer.

6. The display substrate according to claim 1, wherein: The width of the first metal wiring is the same as the width of the second metal wiring, and the width of the gap between adjacent first metal wirings is the same as the width of the gap between adjacent second metal wirings.

7. The display substrate according to claim 6, wherein: The orthographic projection of the first metal trace on the substrate completely overlaps with the orthographic projection of the second metal trace on the substrate.

8. The display substrate according to claim 4, wherein: The base substrate also has a display area located on one side of the fan-shaped area, the first metal layer includes a gate located in the display area, and the second metal layer includes a source and a drain located in the display area; The orthographic projection of the planar layer on the base substrate also covers the orthographic projection of the display area on the base substrate, and the orthographic projection of the second insulating layer on the base substrate also covers the orthographic projection of the display area on the base substrate; The display substrate further comprises: a first transparent conductive layer located between the second insulating layer and the second metal layer, a passivation layer located on a side of the second metal layer away from the base substrate, and a second transparent conductive layer located on a side of the passivation layer away from the base substrate; The first transparent conductive layer is electrically connected to the drain electrode, the second transparent conductive layer includes a plurality of transparent signal lines located in the display area, and an orthographic projection of the first transparent conductive layer on the base substrate overlaps with an orthographic projection of the plurality of transparent signal lines on the base substrate.

9. The display substrate according to claim 8, wherein: The display substrate further comprises a first insulating layer located between the first metal layer and the flat layer; the base substrate further comprises a via region located between the fan-shaped region and the display region, the first metal layer comprises a first switching electrode located in the via region, and the second metal layer comprises a second switching electrode located in the via region; The orthographic projection of the flat layer on the base substrate also covers a portion of the orthographic projection of the via area on the base substrate, and the orthographic projection of the second insulating layer on the base substrate also covers a portion of the orthographic projection of the via area on the base substrate; The second transparent conductive layer includes a plurality of transparent traces located in the via region; Part of the transparent wiring is electrically connected to the first transfer electrode through a via hole that sequentially penetrates the passivation layer, the second insulating layer, the planar layer, and the first insulating layer; Part of the transparent wiring is electrically connected to the second transfer electrode through a via hole penetrating the passivation layer.

10. A method for manufacturing a display substrate, characterized in that: include: providing a substrate base plate; The substrate has a fan-shaped area; Forming a first metal layer on the substrate; wherein the first metal layer includes a plurality of first metal traces located in the fan-shaped area; A flat layer is formed on the side of the first metal layer facing away from the substrate; wherein the orthographic projection of the flat layer on the substrate at least covers the orthographic projection of the fan-shaped area on the substrate; in the fan-shaped area, the surface of the flat layer farthest from the substrate has a highest point with the largest distance to the horizontal plane where the substrate is located and a lowest point with the smallest distance to the horizontal plane where the substrate is located, and the difference in distance between the highest point and the lowest point to the horizontal plane where the substrate is located is less than or equal to 1000 angstroms; A second metal layer is formed on a side of the flat layer away from the base substrate; wherein the second metal layer includes a plurality of second metal traces located in the fan-shaped area, and the orthographic projection of the first metal trace on the base substrate at least partially overlaps with the orthographic projection of the second metal trace on the base substrate; The first metal wiring and the second metal wiring are used to connect the effective display area of ​​the display panel and the driving chip.

11. The method according to claim 10, characterized in that: Before the first metal layer forms a flat layer on the side facing away from the substrate, the method further includes: A first insulating layer is formed between the first metal layer and the planar layer; the orthographic projection of the first insulating layer on the base substrate covers the base substrate.

12. The method according to claim 10, characterized in that: The forming of a flat layer on a side of the first metal layer away from the base substrate is specifically: A flat layer having a thickness greater than that of the first metal layer is formed on a side of the first metal layer away from the base substrate.

13. The manufacturing method according to claim 10, characterized in that: After forming the planar layer and before forming the second metal layer, the method further includes: A second insulating layer is formed between the planar layer and the second metal layer; wherein the orthographic projection of the second insulating layer on the base substrate at least covers the orthographic projection of the fan-shaped area on the base substrate.

14. The method of claim 10, wherein: Forming the plurality of first metal traces specifically includes: Coating a first photoresist layer on a side of the first metal layer facing away from the substrate; Exposing and developing the first photoresist layer to form the plurality of first metal traces; Forming the plurality of second metal traces specifically includes: Coating a second photoresist layer on a side of the second metal layer facing away from the substrate; The second photoresist layer is exposed and developed to form the plurality of second metal wirings corresponding to the plurality of first metal wirings.

15. A display device, characterized in that: Comprising the display substrate as described in any one of claims 1-9.

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