Fabrication method for side traces of a substrate and display panel

Abstract

The present invention provides a method for manufacturing side traces of a substrate and a display panel. The method for manufacturing side traces of the substrate includes: first, providing a substrate, the substrate including a bonding area, the bonding area including a front bonding area and a back bonding area which are oppositely arranged, and a side bonding area connecting the front bonding area and the back bonding area, the front bonding area being provided with a first connection terminal, and the back bonding area being provided with a second connection terminal; then forming a photoresist layer on the bonding area, and using an exposure lamp to expose and develop the photoresist layer to obtain a plurality of wiring areas; then forming a plurality of side traces connecting the first connection terminal and the second connection terminal in the plurality of wiring areas. In the embodiment of the present invention, the cross-sectional shape of the exposure lamp is designed to match the cross-sectional shape of the bonding area, and the irradiation range of the exposure lamp effectively covers the front bonding area, the side bonding area and the back bonding area of the bonding area, thereby improving the uniformity of the line width and line pitch of the side traces.

Description

Technical Field

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

[0002] Miniature light-emitting diodes (Mini-LED or Micro-LED) have been widely used in display panels. However, limited by the Miniature light-emitting diode transfer technology, it is difficult for Miniature light-emitting diode display panels to achieve single-chip large-size display, and large-size products need to be formed by splicing multiple small-size Miniature light-emitting diode display panels.

[0003] As Figure 1 shown, currently, narrow bezel and splicing technologies require the development of a side metal trace process for double-sided manufacturing processes, that is, the side metal traces lead the lines on the front of the display panel to the back of the display panel through the side of the display panel. Currently, the industry mainstream uses the two-side exposure method (as shown in a in Figure 1 ) or the three-side exposure method (as shown in b in Figure 1 ) to expose the photoresist 2 on the side of the substrate 3 using two or three exposure lamps 1. However, the side metal trace process for double-sided manufacturing processes has high requirements for side photoresist exposure. Since neither the two-side exposure method nor the three-side exposure method can well form good light coverage for the entire bonding area, or there is light irradiated to a local area that cannot meet the photoresist energy requirements, it is difficult to ensure the uniformity of the width and pitch of the photoresist pattern formed after photoresist patterning, resulting in poor uniformity of the line width and line pitch of the subsequent formed side metal traces.

[0004] Therefore, it is necessary to provide a technical solution to solve the above problems. Summary of the Invention

[0005] The present invention provides a method for manufacturing side traces of a substrate and a display panel, which can solve the problem of poor uniformity of the line width and line pitch of side metal traces formed by existing processes.

[0006] To solve the above problems, the technical solutions provided by the present invention are as follows:

[0007] An embodiment of the present invention provides a method for manufacturing side traces of a substrate, including the following steps:

[0008] Provide a substrate, the substrate includes a bonding area, the bonding area includes a front bonding area and a back bonding area arranged oppositely, and a side bonding area connecting the front bonding area and the back bonding area. The front bonding area is provided with a first connection terminal, and the back bonding area is provided with a second connection terminal;

[0009] A photoresist layer is formed on the bonding area, and the photoresist layer is exposed and developed to pattern the photoresist layer, resulting in a plurality of wiring areas; wherein, by using one exposure lamp for exposure, in a direction perpendicular to the substrate and perpendicular to the side bonding area, the cross-sectional shape of the exposure lamp matches the cross-sectional shape of the bonding area, and the irradiation range of the exposure lamp covers the front bonding area, the side bonding area, and the back bonding area;

[0010] A plurality of side traces connecting the first connection terminal and the second connection terminal are formed in the plurality of wiring areas.

[0011] Optionally, in some embodiments of the present invention, the light intensity distribution of the exposure lamp is proportional to the thickness relationship of the photoresist layer in the bonding area.

[0012] Optionally, in some embodiments of the present invention, transition areas are formed at the joints of the side bonding area with the front bonding area and the back bonding area respectively, the thickness of the photoresist layer in the transition area is less than the thickness in the area of the bonding area other than the transition area, and the light intensity of the exposure lamp in the transition area is less than the light intensity in the area of the bonding area other than the transition area.

[0013] Optionally, in some embodiments of the present invention, the line widths of the plurality of side traces formed in the bonding area of the substrate are all equal, and the distances between adjacent two side traces are all equal.

[0014] Optionally, in some embodiments of the present invention, the cross-sectional shape of the exposure lamp is arc-shaped or U-shaped.

[0015] Optionally, in some embodiments of the present invention, the wiring area exposes the first connection terminal, the second connection terminal, and the area between the first connection terminal and the second connection terminal.

[0016] Optionally, in some embodiments of the present invention, before forming the photoresist layer on the bonding area, the manufacturing method further includes the following steps:

[0017] Protective films corresponding to the areas outside the bonding area are respectively formed on the front and back of the substrate;

[0018] Wherein, one ends of the first connection terminal and the second connection terminal close to the protective film are both arranged adjacent to the protective film.

[0019] Optionally, in some embodiments of the present invention, after the photoresist layer is exposed and developed, the photoresist layer forms grooves in the corresponding wiring areas, and the grooves have an undercut structure.

[0020] Optionally, in some embodiments of the present invention, the step of forming a side trace connecting the first connection terminal and the second connection terminal in the wiring area includes:

[0021] Form a conductive thin film on the patterned photoresist layer, and the conductive thin film is disconnected at the boundary of the wiring area;

[0022] Remove the protective films on the front and back of the substrate, and remove the remaining photoresist layer and the conductive thin film outside the wiring area. Thus, the production of the side trace of the substrate is completed.

[0023] An embodiment of the present invention further provides a display panel, including a first substrate and a counter substrate, and the first substrate is manufactured by using the manufacturing method of the side trace of the substrate as described above.

[0024] The beneficial effects of the present invention are as follows: The manufacturing method of the side trace of the substrate and the display panel provided by the present invention expose and develop the photoresist layer in the bonding area of the substrate by using an exposure lamp to obtain a plurality of wiring areas; since in the direction perpendicular to the substrate and perpendicular to the side bonding area, the cross-sectional shape of the exposure lamp matches the cross-sectional shape of the bonding area, the irradiation range of the exposure lamp can effectively cover each area of the bonding area, which can improve the uniformity of the width and spacing of the photoresist pattern formed after patterning the photoresist layer, thereby improving the uniformity of the line width and line pitch of the side traces formed in the plurality of wiring areas. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0026] Figure 1 It is a schematic diagram of the manufacturing method of the side trace of the substrate in the prior art;

[0027] Figure 2 It is a flowchart of the manufacturing method of the side trace of the substrate provided by the embodiment of the present invention;

[0028] Figures 3A - 3H It is a schematic diagram of the manufacturing process of the side trace of the substrate provided by the embodiment of the present invention;

[0029] Figure 4 It is a schematic diagram of exposing the photoresist layer by using an exposure lamp provided by the embodiment of the present invention;

[0030] Figure 5 It is a schematic diagram of the structure of the exposure lamp provided by the embodiment of the present invention;

[0031] Figure 6 It is a schematic structural diagram of a substrate with side traces provided by an embodiment of the present invention. Specific Embodiments

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise stated, the orientation terms such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings; and "inner" and "outer" refer to the outline of the device.

[0033] Please refer to Figures 2 - 4 , an embodiment of the present invention provides a method for manufacturing side traces of a substrate. The manufacturing method includes the following steps:

[0034] Step 1: Provide a substrate 10. The substrate 10 includes a bonding area 100. The bonding area 100 includes a front bonding area 1001 and a back bonding area 1002 that are oppositely arranged, and a side bonding area 1003 connecting the front bonding area 1001 and the back bonding area 1002. The front bonding area 1001 is provided with a first connection terminal 110, and the back bonding area 1002 is provided with a second connection terminal 120.

[0035] Step 2: Form a photoresist layer 200 on the bonding area 100, and perform exposure and development on the photoresist layer 200 to pattern the photoresist layer 200 to obtain a plurality of wiring areas 400. Among them, by using an exposure lamp 300 for exposure, in a direction perpendicular to the substrate 10 and perpendicular to the side bonding area 1003, the cross-sectional shape of the exposure lamp 300 matches the cross-sectional shape of the bonding area 100, and the irradiation range of the exposure lamp 300 covers the front bonding area 1001, the side bonding area 1003, and the back bonding area 1002.

[0036] Step 3: Form a plurality of side traces 510 connecting the first connection terminal 110 and the second connection terminal 120 in the plurality of wiring areas 400.

[0037] In an embodiment of the present invention, an exposure lamp 300 is used to expose and develop a photoresist layer 200 in a substrate bonding region 100 to obtain a plurality of wiring regions 400. Since in a direction perpendicular to the substrate 10 and perpendicular to the side bonding region 1003, the cross-sectional shape of the exposure lamp 300 matches the cross-sectional shape of the bonding region 100, the irradiation range of the exposure lamp 300 effectively covers all regions of the bonding region 100, which can improve the uniformity of the width and pitch of the photoresist pattern formed after patterning the photoresist layer 200, thereby improving the uniformity of the line width and line pitch of the side traces 510 formed in the plurality of wiring regions 400.

[0038] The following will introduce in detail the method for manufacturing side traces of the substrate of the present invention in combination with specific embodiments, which is specifically described as follows.

[0039] In one embodiment, the method for manufacturing side traces of the substrate includes the following steps:

[0040] S101, provide a substrate.

[0041] Specifically as Figure 3A shown, the substrate 10 includes a front surface 11 and a back surface 12 arranged opposite to each other, and the substrate 10 further includes a bonding region 100, and the bonding region 100 includes a front bonding region 1001, a back bonding region 1002, and a side bonding region 1003. Among them, the front bonding region 1001 is located on the front surface 11 of the substrate 10, the back bonding region 1002 is located on the back surface 12 of the substrate 10, and the side bonding region 1003 is located on the side of the substrate 10, and the side bonding region 1003 is respectively connected to the front bonding region 1001 and the back bonding region 1002.

[0042] The front bonding region 1001 is provided with a first connection terminal 110, and the back bonding region 1002 is provided with a second connection terminal 120. Specifically, there are at least two first connection terminals 110, and there are also at least two second connection terminals 120. The first connection terminals 110 and the second connection terminals 120 are respectively arranged at intervals in a one-dimensional form on the front surface 11 and the back surface 12 of the substrate 10, and the first connection terminals 110 and the second connection terminals 120 are arranged in one-to-one correspondence.

[0043] The substrate 10 may be an array substrate prepared with a driving circuit, or may be a display substrate prepared with a driving circuit and a light-emitting device. The driving circuit includes signal lines correspondingly connected to the first connection terminals 110, and the light-emitting device may be an OLED light-emitting device, a Mini-LED, or a Micro-LED, but is not limited thereto. Among them, the driving circuit and the light-emitting device are disposed on the front surface 11 of the substrate 10.

[0044] S102, form protective films corresponding to areas outside the bonding areas on the front and back surfaces of the substrate respectively.

[0045] Specifically, as Figure 3B shown, form a first protective film 210 on the front surface 11, and the first protective film 210 covers the area outside the bonding area 100; form a second protective film 220 on the back surface 12, and the second protective film 220 covers the area outside the bonding area 100. Wherein, one end of the first connection terminal 110 close to the first protective film 210 is disposed adjacent to the first protective film 210, and one end of the second connection terminal 120 close to the second protective film 220 is disposed adjacent to the second protective film 220. The first protective film 210 and the second protective film 220 are used to protect the areas that do not need to be plated with a conductive thin film.

[0046] In one embodiment, both the first protective film 210 and the second protective film 220 are polyimide films.

[0047] S103, chamfer the joints between the front bonding area and the side bonding area to form a transition area, and chamfer the joints between the back bonding area and the side bonding area to form a transition area.

[0048] Specifically, as Figure 3C shown, chamfer the joint between the front bonding area 1001 and the side bonding area 1003 to form a first transition area 131, and chamfer the joint between the back bonding area 1002 and the side bonding area 1003 to form a second transition area 132. Since the bonding area 100 is arc-shaped at the corner position, the subsequent formed side traces can make a smooth transition at this corner position, thereby improving the problem that the side traces of the existing substrate are prone to breakage, and avoiding the problem that the side traces are prone to breakage when there are sharp corners at the corner position.

[0049] S104, form a photoresist layer on at least the bonding area, and use an exposure lamp to expose and develop the photoresist layer to pattern the photoresist layer to obtain a plurality of wiring areas.

[0050] Combined with Figures 3C - 3D shown, coat a photoresist layer 200 on the substrate 10, and the photoresist layer 200 covers at least the front bonding area 1001, the side bonding area 1003 and the back bonding area 1002. It can be understood that, in one embodiment, the photoresist layer 200 may also cover the first protective film 210 and the second protective film 220.

[0051] Wherein, the material of the photoresist layer 200 is a negative photoresist.

[0052] Combined withFigures 3D - 3E and Figures 4 - 5 As shown in Figures 4 - 5 , an exposure lamp 300 is used to expose the photoresist layer 200. Among them, in the direction perpendicular to the substrate 10 and perpendicular to the side bonding area 1003, the cross-sectional shape of the exposure lamp 300 matches the cross-sectional shape of the bonding area 100, and the irradiation range of the exposure lamp 300 covers the front bonding area 1001, the side bonding area 1003, and the back bonding area 1002. That is, the entire bonding area 100 can be covered by the light of the exposure lamp 300. Therefore, there is no phenomenon that the width and pitch of the photoresist pattern formed after patterning the photoresist layer are non-uniform due to exposure dead angles.

[0053] As an embodiment, the cross-sectional shape of the exposure lamp 300 is arc-shaped or U-shaped. That is to say, the exposure lamp 300 can be an arc-shaped exposure lamp or a groove-shaped exposure lamp.

[0054] Taking the arc-shaped exposure lamp as an example, as Figure 5 shown, the range of the width a1 of the arc-shaped exposure lamp is 0.5 mm - 1 m, and the range of the length a2 is 0.1 m - 1 m.

[0055] Furthermore, the relationship between the light intensity distribution of the exposure lamp 300 and the thickness of the photoresist layer 200 or the photoresist energy requirement in the bonding area 100 is proportional.

[0056] Generally, the thickness of the photoresist layer 200 in the transition regions (131, 132) is less than the thickness in the regions of the bonding area 100 other than the transition regions (131, 132). That is to say, the thickness of the photoresist layer 200 at the corners of the bonding area 100 is relatively thin, as Figure 4 shown by regions A and B in, and the thickness at other positions is relatively thick. Therefore, the light intensity of the exposure lamp 300 in the transition regions (131, 132) in this embodiment is less than the light intensity in the regions of the bonding area 100 other than the transition regions (131, 132). Since in the exposure process of this embodiment, the exposure intensity at the positions where the thickness of the photoresist layer 200 is relatively thin is weak, and the exposure intensity at the positions where the thickness of the photoresist layer 200 is relatively thick is strong, the width and pitch of the photoresist pattern formed after patterning the photoresist layer 200 can be accurately controlled. In particular, the uniformity of the width and pitch of the photoresist pattern corresponding to the transition regions (131, 132) can be ensured.

[0057] In one embodiment, the light intensity range of the exposure lamp 300 is 0 mj - 500 mj, the exposure time of the exposure lamp 300 is 1 s - 1000 s, and the distance between the exposure lamp 300 and the side of the substrate 10 is 0.01 m - 10 m.

[0058] As Figure 3E shown, after the photoresist layer 200 is exposed and developed, a plurality of wiring regions 400 are obtained. Among them, the wiring regions 400 expose the first connection terminal 110, the second connection terminal 120, and the region between the first connection terminal 110 and the second connection terminal 120.

[0059] Furthermore, after the photoresist layer 200 is patterned, grooves are formed at positions corresponding to the wiring regions 400, and the grooves have an undercut structure.

[0060] S105, forming a conductive thin film on the patterned photoresist layer, and the conductive thin film is disconnected at the boundary of the wiring region.

[0061] As Figure 3F shown, a conductive thin film 500 is formed on the patterned photoresist layer 200. The conductive thin film 500 can be fabricated on the photoresist layer 200 by methods such as magnetron sputtering, three-dimensional evaporation, microelectroplating, or electroless plating.

[0062] Specifically, in the manufacturing method provided by the embodiments of the present invention, the thickness of the conductive thin film 500 can be in the range of 0.5 μm - 1.5 μm. For example, the thickness of the conductive thin film 500 can be 1 μm.

[0063] Specifically, in the manufacturing method provided by the embodiments of the present invention, the material of the conductive thin film 500 can be a conductive metal such as copper, aluminum, or silver, or other conductive metals, which is not specifically limited here and depends on the actual situation.

[0064] Among them, since the groove has an undercut structure, the conductive thin film 500 is easily disconnected at the boundary of the wiring region 400 during the preparation process, thereby forming a side trace 510 connecting the first connection terminal 110 and the second connection terminal 120.

[0065] S106, removing the protective films on the front and back of the substrate, and removing the conductive thin film outside the remaining photoresist layer and the wiring region, thus completing the fabrication of the side trace of the substrate.

[0066] As Figures 3G - 3H shown, the first protective film 210 and the second protective film 220 on the front 11 and the back 12 of the substrate 10 are torn off, and the conductive thin film 500 deposited on the first protective film 210 and the second protective film 220 also falls off together. Then, the conductive thin film 500 outside the remaining photoresist layer 200 and the wiring region 400 is removed.

[0067] The side trace 510 of the substrate 10 can be fabricated by the above method. AsFigure 6 As shown, a first connection terminal 110 and a second connection terminal 120 are provided in the bonding area 100 of the substrate 10, and the first connection terminal 110 and the second connection terminal 120 are electrically connected through the side trace 510.

[0068] Since the widths and spacings of the photoresist patterns have good uniformity, the line widths of the plurality of side traces 510 formed in the bonding area 100 of the substrate 10 are equal, and the distances between adjacent side traces 510 are equal, so that the line widths and line spacings of the side traces 510 also have good uniformity.

[0069] An embodiment of the present invention further provides a display panel, which includes a first substrate and a counter substrate. Among them, the first substrate is manufactured by using the manufacturing method of the side traces of the substrate as described above. Among them, the display panel may be an OLED display panel, a Mini-LED display panel or a Micro-LED display panel, but not limited thereto. A plurality of the display panels may form a tiled screen.

[0070] The embodiments of the present invention have been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A manufacturing method for side traces of a substrate, characterized in that, it includes the following steps: Provide a substrate, the substrate includes a bonding area, the bonding area includes a front bonding area and a back bonding area arranged oppositely, and a side bonding area connecting the front bonding area and the back bonding area. The front bonding area is provided with a first connection terminal, and the back bonding area is provided with a second connection terminal; Form a photoresist layer on the bonding area, expose and develop the photoresist layer to pattern the photoresist layer, and obtain a plurality of wiring areas; wherein, by using an exposure lamp for exposure, in a direction perpendicular to the substrate and perpendicular to the side bonding area, the cross-sectional shape of the exposure lamp matches the cross-sectional shape of the bonding area, and the irradiation range of the exposure lamp covers the front bonding area, the side bonding area and the back bonding area; Form a plurality of side traces connecting the first connection terminal and the second connection terminal in the plurality of wiring areas; The light intensity distribution of the exposure lamp is proportional to the thickness relationship of the photoresist layer in the bonding area.

2. The manufacturing method for side traces of a substrate according to claim 1, characterized in that, Transition areas are formed at the connections of the side bonding area with the front bonding area and the back bonding area respectively. The thickness of the photoresist layer in the transition area is less than the thickness in the area of the bonding area except the transition area, and the light intensity of the exposure lamp in the transition area is less than the light intensity in the area of the bonding area except the transition area.

3. The manufacturing method for side traces of a substrate according to claim 1, characterized in that, The line widths of the plurality of side traces formed in the bonding area of the substrate are all equal, and the distances between adjacent two side traces are all equal.

4. The manufacturing method for side traces of a substrate according to claim 1, characterized in that, The cross-sectional shape of the exposure lamp is arc-shaped or U-shaped.

5. The manufacturing method for side traces of a substrate according to claim 1, characterized in that, The wiring areas expose the first connection terminal, the second connection terminal and the area between the first connection terminal and the second connection terminal.

6. The manufacturing method for side traces of a substrate according to claim 5, characterized in that, Before forming the photoresist layer on the bonding area, the manufacturing method further includes the following steps: Form protective films corresponding to the areas outside the bonding area on the front and back of the substrate respectively; Wherein, one ends of the first connection terminal and the second connection terminal close to the protective film are both arranged adjacent to the protective film.

7. The manufacturing method for side traces of a substrate according to claim 6, characterized in that, After the photoresist layer is exposed and developed, the photoresist layer forms grooves in the corresponding wiring areas, and the grooves have an undercut structure.

8. The manufacturing method for side traces of a substrate according to claim 7, characterized in that, The step of forming side traces connecting the first connection terminal and the second connection terminal in the wiring areas includes: A conductive thin film is formed on the patterned photoresist layer, and the conductive thin film is disconnected at the boundary of the wiring area; The protective films on the front and back surfaces of the substrate are removed, and the remaining photoresist layer and the conductive thin film outside the wiring area are removed, thus completing the fabrication of the side wiring of the substrate.

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