Driving backboard and preparation method thereof

Abstract

The invention discloses a driving backboard and a preparation method thereof, the driving backboard comprises a substrate, a bonding pad and a wire, the substrate comprises a first surface, a second surface and a first side surface, the first surface and the second surface are oppositely arranged, the first side surface is connected with a first end of the first surface and a second end of the second surface, and the bonding pad is arranged on the first side surface in the extension direction of the first surface. The first end protrudes out of the second end; the bonding pad is located on the first surface and protrudes out of the substrate in the extending direction of the first surface; one end of the wire is connected with the bonding pad, and the other end extends to the second surface along the first side surface. Through the scheme, the preparation process of the driving backboard is simple and reliable, and the preparation efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a driving backplane and a preparation method thereof. Background Art

[0002] In recent years, the demand for large-sized LED (light-emitting diode) display panels has gradually increased. In order to achieve large-sized screen display, small-sized sub-panels need to be spliced. In order to reduce the screen border and achieve seamless splicing, the existing technology usually introduces the process of side routing to lead the circuit to the back.

[0003] At present, there is a certain risk in the reliability of the side routing process; and the side routing extends from the front side of the driver backplane through the side to the back side. The process is relatively complicated and requires moving the driver backplane during the preparation process, which is not easy to achieve. Summary of the invention

[0004] The main technical problem solved by the present application is to provide a driving backplane and a preparation method thereof, the preparation process is simple and reliable, and the preparation efficiency is improved.

[0005] In order to solve the above technical problems, a technical solution adopted in the present application is: providing a driving backplane, including a substrate, a pad and a routing, the substrate including a first surface, a second surface and a first side surface, the first surface and the second surface are arranged back to back, the first side surface connects the first end of the first surface and the second end of the second surface, and in the extension direction of the first surface, the first end protrudes from the second end; the pad is located on the first surface, and in the extension direction of the first surface, the pad protrudes from the substrate; one end of the routing is connected to the pad, and the other end extends along the first side surface to the second surface.

[0006] In order to solve the above technical problems, another technical solution adopted in the present application is: to provide a display panel, including the driving backplane in any embodiment.

[0007] To solve the above technical problems, another technical solution adopted in the present application is: providing a method for preparing a driving backplane, including forming a solder pad on the first surface of a substrate, wherein the substrate includes a first surface, a second surface and a third side surface, the first surface and the second surface are arranged back to back, the third side surface connects the first surface and the second surface, and the solder pad includes a fourth side surface; at least the third side surface of the substrate is processed to form a first side surface, and in the extension direction of the first surface, the first end of the first surface protrudes from the second end of the second surface, and one end of the solder pad protrudes from the first end, wherein the first side surface of the substrate connects the first end and the second end; forming a trace, wherein one end of the trace is connected to the solder pad, and the other end extends along the first side surface to the second surface.

[0008] The beneficial effects of the present application are as follows: Different from the prior art, the first end of the first surface of the substrate of the driving backplane of the present application protrudes from the second end of the second surface, and one end of the pad protrudes from the first end of the first surface of the substrate, so that part of the pad can be exposed to the substrate before forming the routing, and subsequently, the routing can be formed on the substrate only in one direction, and the routing and the exposed part of the pad can be overlapped while forming the routing, so as to form a side routing, without forming the side routing on the substrate from multiple directions, and the preparation process is simple. The present application first sets the pad close to the substrate, so that the pad can be exposed while the substrate is processed later, which facilitates the overlap of the routing and the pad, and the process flow is simple and the preparation efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural schematic diagram of an implementation scheme of a driving backplane of the present application;

[0010] Figure 2 is a structural schematic diagram of another embodiment of the driving backplane of the present application;

[0011] Figure 3 is a structural schematic diagram of another embodiment of the driving backplane of the present application;

[0012] Figure 4 It is a schematic flow chart of an implementation method of a driving backplane manufacturing method of the present application;

[0013] Figure 5a-5e It is a structural schematic diagram of each step of the method for preparing the driving backplane of the present application. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and effect of the present application clearer and more specific, the present application is further described in detail with reference to the accompanying drawings and examples. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0015] See also Figure 1 , Figure 1 It is a schematic diagram of the structure of an embodiment of the driving backplane of the present application. The driving backplane 10 includes a substrate 1, a pad 2 and a trace 3, wherein the substrate 1 includes a first surface 11, a second surface 12 and a first side surface 13, the first surface 11 and the second surface 12 are arranged opposite to each other, the first side surface 13 connects the first end 11a of the first surface 11 and the second end 12a of the second surface 12, and in the extension direction of the first surface 11 (X direction in the figure), the first end 11a protrudes from the second end 12a. The pad 2 is located on the first surface 11, and in the extension direction of the first surface 11, the pad 2 protrudes from the first end 11a. One end of the trace 3 is connected to the pad 2, and the other end extends along the first side surface 13 to the second surface 12.

[0016] The first end 11a of the first surface 11 of the substrate 1 of the driving backplane of the present application has an orthographic projection on the plane where the second surface 12 is located outside the second surface 12, and one end of the pad 2 is located outside the first end 11a in the orthographic projection on the plane where the first surface 11 is located, so that part of the pad 2 can be exposed on the substrate 1 in the Z direction before the routing 3 is formed, and subsequently the routing 3 can be formed on the substrate 1 only along one direction (for example, parallel to the Z direction), and the routing 3 can be overlapped with the exposed part of the pad 2 while forming the routing 3, so as to form a side routing. The pad 2 of the present application is used as a part of the side routing, and there is no need to form the side routing on the substrate 1 from multiple directions, and the preparation process is simple.

[0017] Optionally, continue to Figure 1In this embodiment, the driving backplane 10 further includes a flat insulating layer 5, a pixel circuit layer 6 and an electrode 7. The flat insulating layer 5 is located on the side of the pad 2 away from the substrate 1. The flat insulating layer 5 covers the first surface 11 of the substrate 1 and the pad 2, so as to make its surface meet the flattening requirements and play an insulating role. Specifically, the flat insulating layer 5 can be made of organic materials such as photoresist and polyimide. The pixel circuit layer 6 is located on the side of the flat insulating layer 5 away from the substrate 1, and includes a pixel circuit 61 electrically connected to the pad 2. Specifically, a via 51 can be provided on the flat insulating layer 5, and the pixel circuit 61 is electrically connected to the pad 2 through the via 51. The electrode 7 is located on the side of the pixel circuit layer 6 away from the substrate 1, and is electrically connected to the pixel circuit 61. A plurality of electrodes 7 can be provided as electrodes of LED or micro-LED. The pixel circuit 61 is used to power the LED or micro-LED through the electrode 7.

[0018] The above arrangement enables the pad 2 to be located between the flat insulating layer 5 and the substrate 1, so that part of the side wiring is protected and its reliability is improved; and the connection between the pixel circuit 61 and the pad 2 is located inside the flat insulating layer 5, that is, inside the driving backplane 10, which also ensures the reliability of the electrical connection.

[0019] Optionally, continue to Figure 1 In this embodiment, the driving backplane 10 further includes a protective layer 8, which is located on the side of the pixel circuit layer 6 away from the substrate 1, and the electrode 7 is exposed from the protective layer 8. The protective layer 8 is used to protect the pixel circuit 61, and can be made of materials such as photoresist and silicon nitride. The electrode 7 is exposed from the protective layer 8 so that it can be connected to the LED or micro-LED later.

[0020] Optionally, continue to Figure 1 In this embodiment, the first side surface 13 is an inclined surface, and the dihedral angle α formed between the first side surface 13 and the first surface 11 is an acute angle. The first surface 11 and the first side surface 13 are both planes, and the two intersect to form a dihedral angle α. When the dihedral angle α is an acute angle, part of the pad 2 can be exposed in the Z direction, and the first side surface 13 as an inclined plane is more convenient to prepare. Further, when the dihedral angle α is in the range of 30-60° (for example, 45°, etc.), on the one hand, a sufficient area of ​​the pad 2 can be exposed, and on the other hand, the dihedral angle β formed between the first side surface 13 and the second surface 12 is in the range of 120-150°, so that the trace 3 subsequently formed on the first side surface 13 and the second surface 12 has a relatively flat corner at the connection between the first side surface 13 and the second surface 12, and the problem of circuit breaking is not easy to occur, thereby ensuring the reliability of the trace 3.

[0021] Further, see Figure 1In this embodiment, the pad 2 includes a second side surface 21, and the second side surface 21 protrudes from the first end 11a, that is, the orthographic projection of the second side surface on the first surface 11 is located outside the first end 11a, and the second side surface 21 is tangent to the first side surface 13 at the first end 11a. In this embodiment, the first side surface 13 and the second side surface 21 are both inclined surfaces, and the first side surface 13 and the second side surface 21 are coplanar. The above arrangement allows the first side surface 13 and the second side surface 21 to be formed simultaneously, that is, the substrate 1 and the pad 2 can be processed at the same time after the substrate 1 and the pad 2 are formed to form the coplanar first side surface 13 and the second side surface 21, thereby simplifying the preparation process and improving the preparation efficiency. In other embodiments, a step can be formed between the first side surface 13 and the second side surface 21, or the dihedral angle formed between the first side surface 13 and the second side surface 21 can be less than 180°.

[0022] Optionally, the thickness d1 of the pad 2 is greater than the thickness d2 of the pixel circuit layer 6. Specifically, the thickness of the pad 2 is 1-2 μm, and the thickness of the pixel circuit layer 6 is 0.3-0.5 μm. When the pad 2 has sufficient thickness, the exposed second side surface 21 can have a sufficient area (for example, even when the dihedral angle γ formed between the second side surface 21 of the pad 2 and the first surface 11 is close to 90°), thereby ensuring that there is sufficient contact surface with the trace 3 in the subsequent process, thereby ensuring the reliability of the electrical connection between the pad 2 and the trace 3.

[0023] Figure 1 In the embodiment, the first side surface 13 includes a slope. In other embodiments, the first side surface 13 may also be in other forms.

[0024] For example, see Figure 2 , Figure 21 is a schematic diagram of the structure of another embodiment of the drive backplane 10 of the present application. In this embodiment, the first side surface 13 includes two interconnected first sub-side surfaces 131 and second sub-side surfaces 132, and the first sub-side surface 131 and the second sub-side surface 132 are both planes, wherein the first sub-side surface 131 is connected to the first end 11a of the first surface 11, and the second sub-side surface 132 is connected to the second end 12a of the second surface 12. The first side surface 13 protrudes outward from the substrate 1. In this embodiment, the first sub-side surface 131 can be coplanar with the second side surface 21. The structure of the drive backplane 10 of this embodiment can be completed by two processes, for example, firstly processing the substrate 1 and the pad 2 to form the first sub-side surface 131 and the second side surface 21 synchronously, and then processing the substrate 1 to form the second sub-side surface 132. Since the first side surface 13 protrudes outward from the substrate 1, the subsequently formed trace 3 has a flatter corner at the connection between the first sub-side surface 131 and the second surface 12, and at the connection between the first sub-side surface 131 and the second sub-side surface 132, further reducing the probability of a circuit breaker and ensuring the reliability of the trace 3. In other embodiments, the first side surface 13 may also include more than two sub-planes.

[0025] For another example, see Figure 3 , Figure 3 It is a structural schematic diagram of another embodiment of the driving backplane 10 of the present application. In this embodiment, the first side surface 13 is a curved surface protruding toward the outside of the substrate 1. Optionally, the two ends of the first side surface 13 are smoothly connected to the second side surface 21 and the second surface 12, respectively. In this embodiment, the second side surface 21 is also a curved surface, then the first side surface 13 and the second side surface 21 have the same radius of curvature, the first side surface 13 and the second surface 12 are tangent to the second end 12a, and the dihedral angle α formed by the tangent of the first side surface 13 at the first end 11a and the first surface 11 is an acute angle. In other embodiments, the second side surface 21 can also be a plane, then the first side surface 13 and the second side surface 21 are tangent to the second end 12a. The above-mentioned arrangement enables the second surface 12, the first side surface 13 and the second side surface 21 to be connected to a smooth surface, so that the wiring 3 formed thereon further reduces the probability of a circuit breaker, thereby ensuring the reliability of the wiring 3.

[0026] The present application also provides a display device, including the driving backplane 10 in any of the above embodiments. The display panel may be an LED display panel or a micro-LED display panel. Multiple display panels using the above driving backplane 10 may be spliced ​​to form a large-size display panel, and seamless splicing is achieved.

[0027] See also Figure 4 , Figure 5a-5e , Figure 4 is a schematic flow chart of an embodiment of a method for preparing a driving backplane of the present application, Figure 5a-5eSchematic diagram of the structure of each step of the method for preparing the driving backplane of the present application. The preparation method comprises the following steps:

[0028] Step S101: See Figure 5a and Figure 5b , Figure 5b for Figure 5a A top view of the present invention shows that a pad 2 is formed on a first surface 11 of a substrate 1, wherein the substrate 1 includes a first surface 11, a second surface 12, and a third side surface 14, the first surface 11 and the second surface 12 are disposed opposite to each other, and the third side surface 14 connects the first surface 11 and the second surface 12. The pad 2 includes a fourth side surface 20, and the fourth side surface 20 may be coplanar with the third side surface 14.

[0029] The substrate 1 may be made of glass, and the pad 2 may be made of metal. The pad 2 may be formed on the first surface 11 of the substrate 1 by deposition. Specifically, the thickness d1 of the pad 2 in the Z direction is 1-2 μm, and the length l of the pad 2 in the X direction is 10-20 μm, so as to ensure that the subsequent pad 2 has sufficient contact area to overlap with the trace (not shown). Figure 5b As shown, a plurality of pads 2 can be arranged at intervals along the Y direction.

[0030] See also Figure 5c After the preparation of the pad 2 is completed, this step may further include sequentially forming a flat insulating layer 5, a pixel circuit layer 6, an electrode 7 and a protective layer 8 on the side of the pad 2 facing away from the substrate 1, wherein the pixel circuit layer 6 includes a pixel circuit 61 electrically connected to the pad 2, and the electrode 7 is electrically connected to the pixel circuit 61 and exposed to the protective layer 8. Specifically, a via 51 may be formed by exposing the flat insulating layer 5, and then a pixel circuit 61 may be formed on the flat insulating layer 5, and the pixel circuit 61 is electrically connected to the pad 2 through the via 51. Then, an electrode 7 and a protective layer 8 are formed on the side of the pixel circuit layer 6 facing away from the substrate 1, and a plurality of electrodes 7 may be provided, and are electrically connected to the pixel circuit 61, and the electrode 7 is exposed to the protective layer 8.

[0031] In this step, a large piece of glass can be cut into multiple small pieces of substrates 1, and then a solder pad 2, a flat insulating layer 5, a pixel circuit layer 6, an electrode 7, a protective layer 8, etc. can be prepared on each substrate 1; or multiple solder pads 2, a flat insulating layer 5, a pixel circuit layer 6, an electrode 7, a protective layer 8, etc. can be formed on a large piece of glass at the position corresponding to each substrate 1, and then cut to form multiple substrates 1.

[0032] Step S102: Refer to Figure 5d , at least the third side surface 14 of the substrate 1 is processed to form a first side surface 13, the first side surface 13 connects the first end 11a of the first surface 11 and the second end 12a of the second surface 12, and makes the first surface 11 extend in the direction ( Figure 5d), the first end 11a protrudes from the second end 12a, and one end of the pad 2 protrudes from the first end 11a. Optionally, in this step, the fourth side 20 of the pad 2 can also be processed at the same time to form the second side 21, so that the first side 13 and the second side 21 are tangent to the first end 11a. For example, the third side 14 of the substrate 1 and the fourth side 20 of the pad 2 can be polished at the same time by an edge grinder to form the first side 13 and the second side 21, so that the second side 21 protrudes from the substrate 1, which is convenient for subsequent wiring to overlap with the second side 21. In this embodiment, the first side 13 and the second side 21 are coplanar inclined surfaces. In other embodiments, the substrate 1 and the pad 2 can also be polished separately, or they can be polished to form an arc shape or the like. The specific structure can be as described above and will not be repeated here.

[0033] Step S103: Refer to Figure 5e , forming a trace 3, wherein one end of the trace 3 is connected to the pad 2, and the other end extends along the first side surface 13 to the second surface 12. Specifically, the substrate 1 after step 102 can be turned over so that the second surface 12 faces upward, and then a front coating process is used to form a metal film layer on the second surface 12, the first side surface 13, and the second side surface 21 along the Z direction. When the metal film layer is deposited, the trace 3 and the pad 2 can be overlapped, and then a plurality of traces 3 arranged at intervals and corresponding to the pads 2 are etched out through processes such as exposure and etching, thereby forming a side trace.

[0034] The above method enables the preparation of side routing to be completed by performing conventional coating in one direction, without rotating the driving backplane for 3D coating during the coating process. The process is simple and the preparation accuracy is high.

[0035] The above are only implementation methods of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A driving backplane, characterized in that: The driving backplane comprises: A substrate, the substrate comprising a first surface, a second surface and a first side surface, the first surface and the second surface are arranged opposite to each other, the first side surface connects a first end of the first surface and a second end of the second surface, and in an extending direction of the first surface, the first end protrudes beyond the second end; A pad is located on the first surface, and in the extension direction of the first surface, the pad protrudes from the first end; A trace has one end connected to the pad and the other end extending along the first side surface to the second surface.

2. The driving backplane according to claim 1, characterized in that: The first side surface is an inclined surface, and a dihedral angle formed between the first side surface and the first surface is an acute angle.

3. The driving backplane according to claim 1, characterized in that: The pad includes a second side surface, the second side surface protrudes from the first end, and the second side surface is tangent to the first side surface at the first end; Preferably, the first side surface and the second side surface are both inclined surfaces, and the first side surface is coplanar with the second side surface.

4. The driving backplane according to claim 1, characterized in that: The driving backplane also includes: A flat insulating layer, located on a side of the pad facing away from the substrate; a pixel circuit layer, located on a side of the flat insulating layer away from the substrate, and comprising a pixel circuit electrically connected to the pad; an electrode, located at a side of the pixel circuit layer away from the substrate and electrically connected to the pixel circuit; Preferably, the driving backplane further comprises: The protective layer is located on a side of the pixel circuit layer away from the substrate, and the electrode is exposed from the protective layer.

5. The driving backplane according to claim 4, characterized in that: The thickness of the pad is greater than the thickness of the pixel circuit layer; Preferably, the pad has a thickness of 1-2 μm.

6. A display panel, characterized in that: It comprises a driving backplane as claimed in any one of claims 1 to 5.

7. A method for preparing a driving backplane, characterized in that: The method comprises: Forming a pad on the first surface of the substrate, wherein the substrate includes a first surface, a second surface and a third side surface, the first surface and the second surface are arranged opposite to each other, the third side surface connects the first surface and the second surface, and the pad includes a fourth side surface; Processing at least the third side surface of the substrate to form a first side surface, so that in the extension direction of the first surface, the first end of the first surface protrudes from the second end of the second surface, and one end of the pad protrudes from the first end, wherein the first side surface of the substrate connects the first end and the second end; A trace is formed, wherein one end of the trace is connected to the pad, and the other end of the trace extends along the first side surface to the second surface.

8. The method for preparing a driving backplane according to claim 7, characterized in that: The step of processing at least the substrate further comprises: The fourth side surface of the pad is processed to form a second side surface, so that the second side surface of the pad protrudes from the first end, and the first side surface and the second side surface are tangent to the first end.

9. The method for preparing a driving backplane according to claim 7, characterized in that: Before the step of at least processing the substrate, the method further comprises: A flat insulating layer, a pixel circuit layer, an electrode and a protective layer are sequentially formed on the side of the pad away from the substrate, wherein the pixel circuit layer includes a pixel circuit electrically connected to the pad, and the electrode is electrically connected to the pixel circuit and exposed from the protective layer.

10. The method for preparing a driving backplane according to claim 7, characterized in that: The step of at least processing the substrate comprises: At least the substrate is processed by an edge grinding machine.

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