Display panel and manufacturing method of the same

Abstract

A display panel includes a substrate, a pixel array layer, a flexible film, and a circuit board. The substrate has a first surface and a second surface facing away from each other, and has a plurality of conductive vias extending from the first surface to the second surface. The pixel array layer is disposed on the first surface. The flexible film is disposed on the second surface and has a plurality of bonding pads. The plurality of bonding pads are electrically connected to the pixel array layer via the plurality of conductive vias. The flexible film includes a fixing portion and a release portion. The fixing portion is connected to the second surface of the substrate. The release portion extends from the fixing portion and is structurally separated from the substrate. The release portion has a plurality of bonding pads. The circuit board is electrically bonded to at least a portion of the plurality of bonding pads. The circuit board does not overlap the fixing portion of the flexible film along the normal direction of the second surface. A method for manufacturing a display panel is also proposed.

Description

Technical Field

[0001] This invention relates to a display panel, and more particularly to a display panel suitable for splicing displays. Prior Technology

[0002] To achieve a seamless display effect, a technique has been proposed to bond a driving circuit board to the back of the display panel. The driving circuit board is electrically connected to the pixel driving layer on the display side via multiple conductive vias on the glass substrate of the display panel. However, during the bonding process between the driving circuit board and the glass substrate, the driving circuitry and light-emitting elements on the glass substrate are easily damaged by the heat and pressure of the manufacturing process. If the substrate of the display panel is flexible, the aforementioned problems are even more likely to occur. Summary of the Invention

[0003] This invention provides a display panel suitable for splicing displays, with a better production yield.

[0004] This invention provides a method for manufacturing a display panel, wherein the bonding process of the circuit board does not damage other components or structures of the display panel.

[0005] The display panel of the present invention includes a substrate, a pixel array layer, a flexible film, and a circuit board. The substrate has a first surface and a second surface facing away from each other, and is provided with a plurality of conductive vias extending from the first surface to the second surface. The pixel array layer is disposed on the first surface. The flexible film is disposed on the second surface and is provided with a plurality of bonding pads. The plurality of bonding pads are electrically connected to the pixel array layer via the plurality of conductive vias. The flexible film includes a fixing portion and a release portion. The fixing portion is connected to the second surface of the substrate. The release portion extends from the fixing portion and is structurally separated from the substrate. The release portion is provided with a plurality of bonding pads. The circuit board is electrically bonded to at least a portion of the plurality of bonding pads. The circuit board does not overlap the fixing portion of the flexible film along the normal direction of the second surface.

[0006] The present invention discloses a method for manufacturing a display panel, comprising attaching a flexible film to a substrate, forming a plurality of conductive vias penetrating the substrate, performing a release treatment on a portion of the flexible film to form a release portion separated from the substrate structure, and electrically bonding a circuit board to the release portion of the flexible film. The substrate has a first surface and a second surface facing each other. A pixel array layer is disposed on the first surface of the substrate, and a flexible film is disposed on the second surface. A portion of the flexible film that is not subjected to release treatment forms a fixing portion, and the release portion extends from the fixing portion. The circuit board is electrically connected to the pixel array layer via the flexible film and the plurality of conductive vias.

[0007] Based on the above, in a method for manufacturing a display panel according to an embodiment of the present invention, before electrically connecting the circuit board and the substrate, a flexible film is first attached to the surface of the substrate facing away from the pixel array layer, and the flexible film is electrically connected to the pixel array layer through multiple conductive vias penetrating the substrate. Since the circuit board is bonded to the release portion of the flexible film and electrically connected to the pixel array layer through the flexible film and multiple conductive vias, damage to the pixel array layer or circuits on the substrate due to the pressing of the manufacturing equipment can be avoided during the bonding process of the circuit board, which helps to improve the production yield of the display panel. Simple Explanation of the Diagram

[0008] Figure 1 is a schematic diagram of a display panel according to a first embodiment of the present invention. Figures 2A to 2G are cross-sectional schematic diagrams of the manufacturing process of the display panel in Figure 1. Figure 3 is a schematic diagram of a display panel according to a second embodiment of the present invention. Figures 4A to 4C are schematic diagrams of the remanufacturing process of the display panel in Figure 3. Figure 5 is a schematic diagram of a display panel according to a third embodiment of the present invention. Figures 6A to 6I are cross-sectional schematic diagrams illustrating the manufacturing process of a display panel according to a fourth embodiment of the present invention. Figures 7A to 7G are cross-sectional schematic diagrams illustrating the manufacturing process of a display panel according to a fifth embodiment of the present invention. Implementation

[0009] The foregoing descriptions and other technical contents, features, and effects of this invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front, or back, are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0010] Figure 1 is a schematic diagram of a display panel according to a first embodiment of the present invention. Figures 2A to 2G are cross-sectional schematic diagrams of the manufacturing process of the display panel of Figure 1. Referring to Figures 1 and 2G, the display panel 10 includes a substrate 100, a pixel array layer 120, a flexible film 200, and a circuit board 300. The substrate 100 has a first surface 100s1 and a second surface 100s2 facing each other, and is provided with a plurality of conductive vias CTH, wherein these conductive vias CTH extend from the first surface 100s1 of the substrate 100 to the second surface 100s2. In this embodiment, the substrate 100 is, for example, a glass substrate or other suitable rigid substrate.

[0011] A pixel array layer 120 is disposed on a first surface 100s1 of the substrate 100. In this embodiment, the pixel array layer 120 may include a pixel circuit layer (not shown) and a plurality of light-emitting elements (not shown), but is not limited thereto. Notably, the pixel array layer 120 may be electrically connected to a flexible film 200 disposed on a second surface 100s2 via a plurality of conductive vias CTH on the substrate 100. In this embodiment, in addition to the substrate 100, these conductive vias CTH may also penetrate the flexible film 200, but is not limited thereto.

[0012] The flexible membrane 200 may have multiple bonding pads 250 and multiple traces 260, wherein the bonding pads 250 are electrically connected to multiple conductive vias CTH via the multiple traces 260. On the other hand, the flexible membrane 200 may include a fixing portion 210 and a release portion 220. The fixing portion 210 is connected to the second surface 100s2 of the substrate 100. The release portion 220 extends from the fixing portion 210 and is structurally separated from the substrate 100. It should be noted that the aforementioned multiple bonding pads 250 are disposed on the release portion 220 of the flexible membrane 200, while the multiple conductive vias CTH penetrate the fixing portion 210 of the flexible membrane 200.

[0013] The circuit board 300 is electrically bonded to a plurality of bonding pads 250 on the flexible film 200, and electrically connected to the pixel array layer 120 located on the other side of the substrate 100 via a plurality of traces 260 and a plurality of conductive vias (CTHs). In this embodiment, the circuit board 300 may be a flexible circuit board (e.g., COF, chip on film), which may include a flexible substrate 310, a plurality of terminals 330, a driver chip 350, and a plurality of traces (not shown). The plurality of terminals 330 are adjacent to an edge region of the flexible substrate 310, and the driver chip 350 is electrically connected to the plurality of terminals 330 via the plurality of traces. For example, the plurality of terminals 330 on the circuit board 300 may be bonded to the plurality of bonding pads 250 of the flexible film 200 via anisotropic conductive film (ACF), but this is not a limitation.

[0014] In this embodiment, the flexible film 200 does not protrude from any edge of the substrate 100, and therefore does not require bending. That is, in the normal direction of the second surface 100s2, the release portion 220 of the flexible film 200 does not overlap with the fixing portion 210. Therefore, the circuit board 300 bonded to the release portion 220 does not overlap with the fixing portion 210 of the flexible film 200. For example, an adhesive (e.g., tape) can be used to fix one end of the release portion 220 away from the fixing portion 210 to the second surface 100s2, so that the flexible film 200 is substantially flat on the second surface 100s2 of the substrate 100, but this is not a limitation.

[0015] Furthermore, the flexible film 200 has a flexible film edge 200e away from the release portion 220. The substrate 100 has a substrate edge 100e adjacent to the flexible film edge 200e. The flexible film 200 (as shown in FIG. 2G), which is generally flat on the second surface 100s2 of the substrate 100, has its fixing portion 210 and release portion 220 arranged along a direction parallel to the second surface 100s2 (e.g., direction X). Alternatively, the release portion 220 extends from the fixing portion 210 along direction X.

[0016] To ensure the stability of the overall structure, the ratio d1 / L1 of the distance d1 between the flexible membrane edge 200e and the substrate edge 100e along the X direction to the length L1 of the substrate 100 along the X direction must be greater than or equal to 0.1. Furthermore, to prevent the flexible membrane 200 or the circuit board 300 from protruding from the other substrate edge of the substrate 100 relative to the substrate edge 100e, the ratio d1 / L1 must be less than or equal to 0.2.

[0017] On the other hand, to ensure the structural stability of the conductive vias CTH, the ratio d2 / L2 of the distance d2 between each conductive via CTH and the edge 200e of the flexible membrane along the X direction to the length L2 of the flexible membrane 200 along the X direction must be greater than or equal to 0.1. Furthermore, to ensure that the flexible membrane 200 has sufficient release portion 220, the ratio d2 / L2 must be less than or equal to 0.2.

[0018] In order to avoid affecting the bonding between the circuit board 300 and the multiple bonding pads 250 on the flexible membrane 200, the ratio d3 of the distance d3 between the multiple conductive vias CTH and the multiple bonding pads 250 along the X direction to the length L2 of the flexible membrane 200 along the X direction is greater than or equal to 0.5.

[0019] The manufacturing method of the display panel 10 will be described exemplarily below.

[0020] First, a substrate 100 with a pixel array layer 120 is provided. The pixel array layer 120 can be fabricated using any conventional process method, which will not be described in detail here. Next, a flexible film 200 is attached to the side surface of the substrate 100 opposite to the pixel array layer 120 (e.g., the second surface 100s2), as shown in FIG2A. For example, the flexible film 200 can be attached to the second surface 100s2 of the substrate 100 via a release layer 150. The material of the release layer 150 is not limited, as long as the adhesion between part of the flexible film 200 and the substrate 100 can be broken by a corresponding release step in subsequent processes.

[0021] After the flexible membrane 200 is attached, a plurality of conductive vias CTH are formed through the substrate 100, as shown in Figures 2B and 2C. In this embodiment, the step of forming a plurality of conductive vias CTH may include penetrating a portion of the substrate 100 and a portion of the flexible membrane 200 to form a plurality of vias TH, and filling the vias with a conductive material to form a plurality of conductive vias CTH. For example, copper electroplating or silver paste filling and sintering can be used to fill the vias, but this is not a limitation.

[0022] After forming multiple conductive vias CTH, multiple bonding pads 250 and multiple traces 260 are formed on the flexible film 200, as shown in FIG2D. The multiple bonding pads 250 are electrically connected to the multiple conductive vias CTH via the multiple traces 260. In this embodiment, the bonding pads 250 and traces 260 are formed on the surface of the flexible film 200 facing away from the substrate 100, but the invention is not limited thereto. For example, in this embodiment, photolithography can be used to fabricate the bonding pads 250 and traces 260, but this is not a limitation.

[0023] Referring to Figure 2E, after the bonding pad 250 and the trace 260 are fabricated, a portion of the flexible film 200 is released to form a release portion 220 structurally separated from the substrate 100, while the remaining portion of the flexible film 200 without release treatment forms a fixed portion 210. For example, the release treatment step may include heating or irradiating the release layer 150 with light (e.g., ultraviolet light) to reduce the adhesiveness of the release layer 150, but is not limited thereto. From another perspective, the release portion 220 of the flexible film 200 can be generally defined by the portion of the flexible film 200 that is connected to the release layer 150 before the release treatment.

[0024] Next, the circuit board 300 is electrically bonded to the release portion 220 of the flexible film 200, as shown in FIG2F. More specifically, the circuit board 300 is electrically bonded to a plurality of bonding pads 250 located on the release portion 220. In this embodiment, the bonding process between the circuit board 300 and the plurality of bonding pads 250 includes, for example, attaching an anisotropic conductive film (ACF) to the plurality of bonding pads 250 of the flexible film 200, aligning and bonding the circuit board 300 and the plurality of bonding pads 250, and thermosetting and curing the anisotropic conductive film between the circuit board 300 and the plurality of bonding pads 250, but is not limited thereto.

[0025] It should be noted that during the bonding process, the circuit board 300 is bonded to the release portion 220 of the flexible film 200, not the substrate 100. Therefore, damage to the pixel array layer 120 or circuits on the substrate 100 due to the pressing of the manufacturing equipment can be avoided, which helps to improve the production yield of the display panel.

[0026] After the circuit board 300 is bonded, an adhesive (such as tape) can be used to fix the end of the release portion 220 away from the fixing portion 210 onto the second surface 100s2, so that the flexible film 200 is substantially flat on the second surface 100s2 of the substrate 100, as shown in FIG2G. At this point, the fabrication of the display panel 10 of FIG1 is completed.

[0027] In this embodiment, a pixel array layer 120 is provided on the first surface 100s1 of the substrate 100 of the display panel 10, and a flexible film 200 is provided on the second surface 100s2 of the substrate 100 opposite to the first surface 100s1. A plurality of bonding pads 250 are provided on the flexible film 200, and these bonding pads 250 are electrically connected to the pixel array layer 120 on the other side of the substrate 100 via a fixing portion 210 penetrating the flexible film 200 and a plurality of conductive vias CTH of the substrate 100. To avoid damage to the circuits or components on the substrate 100 during the bonding process of the circuit board 300, in this embodiment, the circuit board 300 is directly electrically bonded to the plurality of bonding pads 250 on the release portion 220 of the flexible film 200 to achieve an electrical connection between the circuit board 300 and the pixel array layer 120.

[0028] The following examples illustrate this disclosure in detail, wherein the same components will be labeled with the same symbols, and descriptions of the same technical content will be omitted. For the omitted parts, please refer to the foregoing examples, which will not be repeated below.

[0029] Figure 3 is a schematic diagram of a display panel according to a second embodiment of the present invention. Figures 4A to 4C are schematic flowcharts of the rework process of the display panel of Figure 3. Referring to Figure 3, the difference between the display panel 10A of this embodiment and the display panel 10 of Figure 1 is that the arrangement of the multiple bonding pads on the flexible film is different. Specifically, in the display panel 10A of this embodiment, two bonding areas may be provided on the release portion 220 of the flexible film 200A, namely a first bonding area BA1 and a second bonding area BA2, wherein the second bonding area BA2 is located between the first bonding area BA1 and the fixing portion 210.

[0030] Correspondingly, the plurality of bonding pads 250A in this embodiment can be divided into two groups, for example, a plurality of first bonding pads 251 located in the first bonding region BA1 and a plurality of second bonding pads 252 located in the second bonding region BA2. Therefore, the flexible membrane 200A is provided with a plurality of first traces 261 and a plurality of second traces 262, wherein the plurality of first traces 261 electrically connect the plurality of first bonding pads 251 and the plurality of second bonding pads 252, and the plurality of second traces 262 electrically connect the plurality of second bonding pads 252 and the plurality of conductive vias CTH.

[0031] By setting up two bonding areas, the display panel 10A can undergo rework of the circuit board 300 during the manufacturing process. For example, if the circuit board 300 in Figure 3 is detected as abnormal or damaged for any reason, it can be replaced using the above configuration. The rework process of the display panel 10A will be illustrated below.

[0032] Referring to Figures 3 and 4A, firstly, the faulty or damaged circuit board 300 is removed from the plurality of first bonding pads 251. Next, a disconnection step is performed on the plurality of first traces 261, making the plurality of first bonding pads 251 electrically independent of the plurality of second bonding pads 252, as shown in Figure 4B. After the disconnection step is completed, the repair circuit board 300R is electrically bonded to the plurality of second bonding pads 252, as shown in Figure 4C. Since the bonding process between the repair circuit board 300R and the plurality of second bonding pads 252 is similar to the bonding process between the circuit board 300 and the plurality of bonding pads 250 in Figure 1, detailed descriptions can be found in the relevant paragraphs of the foregoing embodiments, and will not be repeated here. This completes the rework process of the display panel 10A.

[0033] Figure 5 is a schematic diagram of a display panel according to a third embodiment of the present invention. Referring to Figure 5, the difference between the display panel 10B of this embodiment and the display panel 10 of Figure 1 is that the size of the release portion of the flexible film is different. Specifically, in the display panel 10B of this embodiment, the release portion 220B of the flexible film 200B is shorter than the release portion 220 of the flexible film 200 in Figure 1, so the driving chip 350 of the circuit board 300 does not overlap with the release portion 220B of the flexible film 200B. By shortening the length of the release portion 220B of the flexible film 200B, the component layout space between the circuit board 300 and the substrate 100 can be increased. For example, other chips or electronic components can also be disposed on the surface of the circuit board 300 facing the substrate 100.

[0034] Figures 6A to 6I are cross-sectional schematic diagrams illustrating the manufacturing process of a display panel according to a fourth embodiment of the present invention. Referring to Figure 6I, the difference between the display panel 10C of this embodiment and the display panel 10 of Figure 2G lies in the different substrate materials and the different positions of the circuit board, bonding pads, and traces.

[0035] Specifically, in the display panel 10C of this embodiment, the substrate 100A is, for example, a flexible substrate, whose material includes, for example, polycarbonate (PC), polyimide (PI), polypropylene (PP), polyethylene terephthalate (PET), other suitable flexible materials, or combinations of the foregoing materials, but is not limited thereto. On the other hand, in this embodiment, the plurality of bonding pads 250, the plurality of traces 260, and the circuit board 300 are all located between the flexible film 200 and the substrate 100A.

[0036] The manufacturing method of the display panel 10C will be described exemplarily below.

[0037] First, the flexible film 200 is attached to the glass substrate GS, as shown in Figure 6A. For example, the flexible film 200 can be attached to the glass substrate GS via a release layer RL. The material of the release layer RL is not limited, as long as the adhesion between part of the flexible film 200 and the glass substrate GS can be broken through the corresponding release step in subsequent processes. Next, multiple bonding pads 250 and multiple traces 260 are formed on the flexible film 200, as shown in Figure 6B. For example, in this embodiment, photolithography can be used to fabricate the bonding pads 250 and the traces 260, but this is not a limitation.

[0038] Referring to Figure 6C, after fabricating multiple bonding pads 250 and multiple traces 260, the flexible film 200 is attached to the substrate 100A. For example, the flexible film 200 can be attached to the second surface 100s2 of the substrate 100A via a release layer 150. The material of the release layer 150 is not limited, as long as the adhesion between part of the flexible film 200 and the substrate 100A can be broken through the corresponding release step in subsequent processes.

[0039] It should be noted that, since the substrate 100A in this embodiment is a flexible substrate, in order to avoid the substrate 100A from curling during the manufacturing process, the thickness t1 of the flexible film 200 can be greater than the thickness t2 of the substrate 100A, but is not limited thereto. Unlike the manufacturing method of the display panel 10 in FIG1, the manufacturing method of the display panel 10C in this embodiment completes the fabrication of multiple bonding pads 250 before the flexible film 200 is attached to the substrate 100A.

[0040] After the flexible membrane 200 is attached, a plurality of conductive vias CTH” are formed through the substrate 100A, as shown in Figures 6D and 6E. In this embodiment, the step of forming a plurality of conductive vias CTH” may include penetrating a portion of the substrate 100 to form a plurality of vias TH” and filling the vias with a conductive material to form a plurality of conductive vias CTH”. For example, copper electroplating or silver paste filling and sintering can be used to fill the vias, but this is not a limitation.

[0041] It is particularly noteworthy that the electrical connection between the pixel array layer 120 located on opposite sides of the substrate 100A and the plurality of bonding pads 250 can be achieved after the formation of the plurality of conductive vias CTH". Next, the glass substrate GS is removed, as shown in Figures 6E and 6F. For example, in this embodiment, the removal step of the glass substrate GS may include heating or irradiating the release layer RL with light (e.g., ultraviolet light) to reduce the adhesion of the release layer RL, but is not limited thereto.

[0042] Referring to Figures 6F and 6G, a portion of the flexible film 200 undergoes a release treatment to form a release portion 220 that is structurally separated from the substrate 100A, while the remaining portion of the flexible film 200 that is not subjected to the release treatment forms a fixed portion 210. For example, the release treatment step may include heating or irradiating the release layer 150 with light (e.g., ultraviolet light) to reduce the adhesiveness of the release layer 150, but is not limited thereto.

[0043] Next, the circuit board 300 is electrically bonded to the release portion 220 of the flexible film 200, as shown in FIG6H. More specifically, the circuit board 300 is electrically bonded to a plurality of bonding pads 250 located on the release portion 220. In this embodiment, the bonding process between the circuit board 300 and the plurality of bonding pads 250 includes, for example, attaching an anisotropic conductive film (ACF) to the plurality of bonding pads 250 of the flexible film 200, aligning and bonding the circuit board 300 and the plurality of bonding pads 250, and thermosetting and curing the anisotropic conductive film between the circuit board 300 and the plurality of bonding pads 250, but is not limited thereto.

[0044] It should be noted that during the bonding process, the circuit board 300 is bonded to the release portion 220 of the flexible film 200, not the substrate 100A. Therefore, damage to the pixel array layer 120 or circuits on the substrate 100A due to the pressing of the manufacturing equipment can be avoided, which helps to improve the production yield of the display panel.

[0045] On the other hand, since the circuit board 300 in this embodiment is bonded to the side of the flexible film 200 facing the substrate 100A, during the bonding process of the circuit board 300, the angle θ2 between the surface 220s of the release portion 220 of the flexible film 200 and the second surface 100s2 of the substrate 100A will be relatively large to form sufficient space for bonding of the circuit board 300. Conversely, since the circuit board 300 of the display panel 10 in FIG1 is bonded to the side of the flexible film 200 facing away from the substrate 100, during the bonding process of the circuit board 300, the angle θ1 between the surface 220s of the release portion 220 of the flexible film 200 and the second surface 100s2 of the substrate 100 will be smaller than the angle θ2 in this embodiment. In this way, excessive bending of the flexible film 200 during the bonding process of the circuit board 300 can be avoided, which could damage the circuits on the flexible film 200.

[0046] After the circuit board 300 is bonded, an adhesive (such as tape) can be used to fix the end of the release portion 220 away from the fixing portion 210 onto the second surface 100s2, so that the flexible film 200 is substantially flat on the second surface 100s2 of the substrate 100A, as shown in FIG6I. This completes the fabrication of the display panel 10C of this embodiment.

[0047] Figures 7A to 7G are cross-sectional schematic diagrams illustrating the manufacturing process of a display panel according to a fifth embodiment of the present invention. Referring to Figure 7G, the difference between the display panel 10D of this embodiment and the display panel 10 of Figure 2I lies in the different substrate materials and manufacturing methods.

[0048] Specifically, in the display panel 10D of this embodiment, the substrate 100A is, for example, a flexible substrate, the material of which includes, for example, polycarbonate (PC), polyimide (PI), polypropylene (PP), polyethylene terephthalate (PET), other suitable flexible materials or combinations of the foregoing materials, but is not limited thereto.

[0049] The manufacturing method of the 10D display panel will be described in an exemplary manner below.

[0050] First, substrate 100A is attached to glass substrate GS, and a pixel array layer 120 is formed on the first surface 100s1 of substrate 100A facing away from glass substrate GS, as shown in FIG7A. For example, substrate 100A can be attached to glass substrate GS via release layer RL, wherein the material of release layer RL is not limited, as long as the adhesion between substrate 100A and glass substrate GS can be partially broken through the corresponding release step in subsequent processes.

[0051] After the pixel array layer 120 is fabricated, the release layer RL is released to remove the glass substrate GS and expose the second surface 100s2 of the substrate 100A, as shown in FIG7B. For example, in this embodiment, the removal step of the glass substrate GS may include heating or irradiating the release layer RL with light (e.g., laser light) to reduce the adhesion of the release layer RL, but is not limited thereto. Next, the flexible film 200 is attached to the second surface 100s2 of the substrate 100A. For example, the flexible film 200 may be attached to the substrate 100A via the release layer 150, wherein the material of the release layer 150 is not limited, as long as the adhesion between part of the flexible film 200 and the substrate 100A can be invalidated by the corresponding release step in subsequent processes.

[0052] It should be noted that before the flexible film 200 is attached to the substrate 100A, a plurality of bonding pads 250 and a plurality of traces 260 have been formed on it. For example, in this embodiment, a printing process can be used to form a plurality of bonding pads 250 and a plurality of traces 260 on the flexible film 200, but this is not a limitation. In other embodiments, depending on the process sequence or the required trace density, different process technologies (such as photolithography) can also be used to form the bonding pads 250 and traces 260.

[0053] After the flexible membrane 200 is attached, a plurality of conductive vias CTH are formed penetrating the substrate 100A and the flexible membrane 200, as shown in Figures 7C and 7D. In this embodiment, the step of forming a plurality of conductive vias CTH may include penetrating a portion of the substrate 100A and a portion of the flexible membrane 200 to form a plurality of vias TH, and filling the vias with a conductive material to form a plurality of conductive vias CTH. For example, copper electroplating or silver paste filling and sintering can be used to fill the vias, but this is not a limitation.

[0054] It is particularly noteworthy that the electrical connection between the pixel array layer 120 located on opposite sides of the substrate 100A and the multiple bonding pads 250 can be achieved after the formation of multiple conductive vias CTH.

[0055] Referring to Figure 7E, after the fabrication of multiple conductive vias CTH is completed, a portion of the flexible film 200 undergoes a release treatment to form a release portion 220 that is structurally separated from the substrate 100A. The remaining portion of the flexible film 200 that is not subjected to the release treatment forms a fixed portion 210. For example, the release treatment step may include heating or irradiating the release layer 150 with light (e.g., ultraviolet light) to reduce the adhesiveness of the release layer 150, but is not limited thereto.

[0056] Next, the circuit board 300 is electrically bonded to the release portion 220 of the flexible film 200, as shown in FIG7F. More specifically, the circuit board 300 is electrically bonded to a plurality of bonding pads 250 located on the release portion 220. In this embodiment, the bonding process between the circuit board 300 and the plurality of bonding pads 250 includes, for example, attaching an anisotropic conductive film (ACF) to the plurality of bonding pads 250 of the flexible film 200, aligning and bonding the circuit board 300 and the plurality of bonding pads 250, and thermosetting and curing the anisotropic conductive film between the circuit board 300 and the plurality of bonding pads 250, but is not limited thereto.

[0057] It should be noted that during the bonding process, the circuit board 300 is bonded to the release portion 220 of the flexible film 200, not the substrate 100A. Therefore, damage to the pixel array layer 120 or circuits on the substrate 100A due to the pressing of the manufacturing equipment can be avoided, which helps to improve the production yield of the display panel.

[0058] After the circuit board 300 is bonded, an adhesive (such as tape) can be used to fix the end of the release portion 220 away from the fixing portion 210 onto the second surface 100s2, so that the flexible film 200 is substantially flat on the second surface 100s2 of the substrate 100A, as shown in FIG7G. This completes the fabrication of the display panel 10D of this embodiment.

[0059] In summary, in the manufacturing method of a display panel according to an embodiment of the present invention, before electrically connecting the circuit board and the substrate, a flexible film is first attached to the surface of the substrate opposite to the pixel array layer, and the flexible film is electrically connected to the pixel array layer through multiple conductive vias penetrating the substrate. Since the circuit board is bonded to the release portion of the flexible film and electrically connected to the pixel array layer through the flexible film and multiple conductive vias, damage to the pixel array layer or circuits on the substrate due to the pressing of the manufacturing equipment can be avoided during the bonding process of the circuit board, which helps to improve the production yield of the display panel.

[0060] 10, 10A, 10B, 10C, 10D: Display panels 100, 100A: substrate 100e: Substrate edge 100s1: First surface 100s2: Second surface 120: Pixel Array Layer 150, RL: Release layer 200, 200A, 200B: Flexible membrane 200e: Flexible membrane edge 210: Fixed part 220, 220B: Release portion 220s: Surface 250, 250A: Joint pads 251: First joint pad 252: Second joint pad 260: Wiring 261: First route 262: Second route 300: Circuit board 300R: Circuit board for repair 310:Soft substrate 330:Terminal 350: Driver chip BA1: First junction region BA2: Second junction region CTH, CTH”: Conductive via d1, d2, d3: Distance GS: Glass substrate L1, L2: Length TH、TH”: Through-hole t1, t2: thickness X: Direction θ1, θ2: included angle

Claims

1. A display panel, comprising: A substrate having a first surface and a second surface facing away from each other, and having a plurality of conductive vias extending from the first surface to the second surface; a pixel array layer disposed on the first surface; a flexible film disposed on the second surface and having a plurality of bonding pads electrically connected to the pixel array layer via the conductive vias, the flexible film comprising: a fixing portion connected to the second surface of the substrate; and a release portion extending from the fixing portion and structurally separated from the substrate, the release portion having the bonding pads; and a circuit board electrically bonded to at least a portion of the bonding pads, wherein the circuit board does not overlap the fixing portion of the flexible film along the normal direction of the second surface, wherein the release portion and the fixing portion are arranged along a direction, and the ratio of a distance between the conductive vias and the bonding pads along the direction to a length of the flexible film along the direction is greater than or equal to 0.

5.

2. The display panel as claimed in claim 1, wherein the bonding pads comprise: Multiple first bonding pads are disposed in a first bonding area of ​​the release portion; And a plurality of second bonding pads are disposed in a second bonding area of ​​the release portion, wherein the second bonding area is located between the first bonding area and the fixing portion.

3. The display panel as claimed in claim 1, wherein the circuit board has a driving chip and the driving chip does not overlap the flexible film.

4. The display panel as claimed in claim 1, wherein the flexible film has a flexible film edge away from the release portion, the substrate has a substrate edge adjacent to the flexible film edge, the release portion and the fixing portion are arranged along the direction, and the ratio of a distance between the flexible film edge and the substrate edge along the direction to a length of the substrate along the direction is greater than or equal to 0.1 and less than or equal to 0.

2.

5. The display panel as claimed in claim 1, wherein the flexible film has a flexible film edge away from the release portion, the release portion and the fixed portion are arranged along the direction, and the ratio of a distance between each of the conductive vias and the edge of the flexible film along the direction to the length of the flexible film along the direction is greater than or equal to 0.1 and less than or equal to 0.

2.

6. The display panel as claimed in claim 1, wherein the conductive vias also penetrate the fixed portion of the flexible film.

7. The display panel as claimed in claim 1, wherein the substrate is a flexible substrate and the thickness of the flexible film is greater than the thickness of the flexible substrate.

8. A method for manufacturing a display panel, comprising: A flexible film is attached to a substrate, wherein the substrate has a first surface and a second surface facing away from each other, a pixel array layer is disposed on the first surface of the substrate, and the flexible film is disposed on the second surface; a plurality of conductive vias are formed through the substrate; a portion of the flexible film is released to form a release portion that is structurally separated from the substrate, wherein another portion of the flexible film that is not released forms a fixed portion, and the release portion extends from the fixed portion; and a circuit board is electrically bonded to the release portion of the flexible film, wherein the circuit board is electrically connected to the pixel array layer via the flexible film and the conductive vias.

9. The method of manufacturing a display panel as described in claim 8, further comprising: A plurality of bonding pads and a plurality of traces are formed on the flexible film, wherein the bonding pads are located on the release portion of the flexible film and are electrically connected to the conductive vias via the traces, and the circuit board is electrically bonded to at least a portion of the bonding pads.

10. A method of manufacturing a display panel as claimed in claim 9, wherein the bonding pads are formed before the flexible film is attached to the substrate.

11. A method of manufacturing a display panel as claimed in claim 9, wherein the bonding pads are formed after the conductive vias are formed.

12. The method of manufacturing a display panel as described in claim 9, further comprising: Remove the circuit board from the multiple first bonding pads of the bonding pads; And a plurality of second bonding pads electrically bonding the circuit board for repair to the bonding pads, wherein the traces include a plurality of first traces and a plurality of second traces, the first traces electrically connecting the first bonding pads and the second bonding pads, and the second traces electrically connecting the second bonding pads and the conductive vias.

13. The method of manufacturing a display panel as described in claim 12, further comprising: A disconnection step is performed on these first traces to make the electrical properties of the first bonding pads independent of the second bonding pads.

14. A method of manufacturing a display panel as claimed in claim 8, wherein the step of forming the conductive vias comprises: The conductive vias are formed by penetrating a portion of the substrate and a portion of the flexible film.

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