Display panel with ultra-narrow lower frame and display device

Abstract

The application provides an ultra-narrow lower frame display panel and device, wherein the lower frame area of the display panel comprises: a cover glass side sequentially provided with an optical transparent adhesive and a polarizer; the other side of the polarizer is provided with a substrate assembly containing a substrate glass, the lower frame area of the substrate glass is provided with a plurality of through holes penetrating through the thickness direction, the holes are filled with conductive filling medium; the side of the substrate glass away from the polarizer is provided with a first pad array, a plurality of first pads of the first pad array are respectively electrically connected with the conductive filling medium of the through holes; the side is also provided with a driving chip and a chip on film layer, the chip on film layer carries the driving chip, one end of the chip on film layer is provided with a second pad array, the chip on film layer is respectively electrically connected with a flexible substrate and a driving chip pin, and the first pad array and the second pad array are correspondingly bound. The application transmits the front wiring to the back binding through the through hole, cancels the lower frame binding pad area and the film bending convex amount, makes the lower frame width less than 800 microns, and realizes the four-side equal-width narrow frame design.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more specifically, to display panels and display devices with ultra-narrow bottom bezels. Background Technology

[0002] With the increasing popularity and upgrading of consumer electronics products, especially portable devices such as smartphones, tablets, and laptops, users are constantly raising their standards for screen display effects and aesthetic appeal. Among these, "narrow bezel" and even "full-screen" designs have become important hallmarks of high-end devices and a focal point of market competition. Narrow bezel designs can significantly increase the screen-to-body ratio, providing a larger viewing area without changing the device size, resulting in a more immersive visual experience, while also making the device look more refined and modern.

[0003] The bezel width of a display panel is primarily limited by factors such as internal structural layout, drive circuit connection methods, material properties, and manufacturing processes. Typically, the widths of the left, right, and top bezels are relatively easy to control, and can be reduced to a lower level, such as 800 micrometers or even narrower, through optimization of pixel design, wiring layout, and packaging technology. However, the width of the bottom bezel often becomes a bottleneck restricting the overall bezel narrowing and even achieving a four-sided equal-width design. This is mainly because the bottom bezel needs to accommodate the electrical connection structure between the drive integrated circuit and the display panel body.

[0004] In view of this, the present invention provides a display panel with an ultra-narrow bottom bezel and a display device.

[0005] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this invention, and therefore may contain information that is unknown to those skilled in the art and does not constitute prior art. Summary of the Invention

[0006] In view of this, the present invention provides a display panel and display device with an ultra-narrow bottom bezel, which overcomes the difficulties of the prior art, can significantly reduce the planar space required for the bonding area, reduce the limitation of process temperature on the front device, and thus ultimately achieve a significant reduction in the width of the bottom bezel.

[0007] This invention provides a display panel with an ultra-narrow bottom bezel, wherein the bottom bezel area of ​​the display panel includes: A cover glass panel; An optically transparent adhesive is applied to one side of the cover glass. A polarizer is disposed on the side of the optically transparent adhesive that is away from the cover glass; A substrate assembly is disposed on the side of the polarizer away from the optically transparent adhesive. The substrate assembly includes a substrate glass. The lower frame area of ​​the substrate glass is provided with a plurality of through holes penetrating its thickness direction. The through holes are filled with a conductive filling medium. A first pad array is disposed on the side of the substrate glass opposite to the polarizer. The first pad array includes a plurality of first pads, each of which is electrically connected to the conductive filling medium of the via. A driver chip is disposed on the side of the substrate glass opposite to the polarizer; and A flip-chip thin film layer is provided, on which the driver chip is carried. A second pad array is provided at one end of the flip-chip thin film layer. The second pad array includes a plurality of second pads. The flip-chip thin film layer is electrically connected to a flexible substrate and the pins of the driver chip respectively. The first pad array and the second pad array are correspondingly bonded.

[0008] Preferably, the aperture of the through hole is 15 micrometers to 25 micrometers, and the center distance between adjacent through holes is 30 micrometers to 50 micrometers.

[0009] Preferably, the through holes are arranged in multiple rows in the lower frame region of the substrate glass, and the through holes in adjacent rows are staggered along the thickness direction of the substrate glass.

[0010] Preferably, the first pad is a first strip-shaped pad that extends along the length direction of the substrate glass and is staggered along the width direction; The second pad is a second strip pad that extends along the length direction of the substrate glass and is staggered along the width direction. Each second strip pad is independently bonded to the corresponding first strip pad. The first arrangement pattern of the first pad array overlaps with the second arrangement pattern of the second pad array.

[0011] Preferably, the substrate glass has a preset area corresponding to the effective display area, and the first strip pad extends from the through hole to the preset area and at least partially enters the preset area.

[0012] Preferably, the wall of the through hole is provided with a chemically plated copper layer, and the conductive filling medium is electroplated copper.

[0013] Preferably, it further includes an ink layer, which is disposed in the peripheral non-display area of ​​the cover glass on the side facing the optically transparent adhesive, and the orthographic projection of the ink layer on the substrate glass covers the area where the through hole is located.

[0014] Preferably, the polarizer covers the area where the through-hole is located in the substrate glass.

[0015] Preferably, the bottom bezel width of the display panel is less than 800 micrometers.

[0016] Preferably, the lower frame area of ​​the substrate glass does not have front bonding pads, and the second pad array of the flip-chip thin film layer is bonded to the first pad array through a low-temperature bonding process.

[0017] The present invention also provides a display device including the display panel with the ultra-narrow bottom bezel described above.

[0018] The present invention also utilizes the combination of the first pad and the via array to make full use of the edge space of the substrate glass to make dense through-line routing without using bent traces, thereby reducing the welding difficulty between the substrate and the flip-chip thin film layer and improving the yield. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] Figure 1 This is a schematic diagram of a display panel with an ultra-narrow bottom bezel, based on existing technology.

[0021] Figure 2 This is a schematic diagram of a display panel with an ultra-narrow bottom bezel according to the present invention.

[0022] Figure 3 This is a schematic diagram of the through-hole arrangement in the substrate glass of a display panel with an ultra-narrow bottom bezel according to the present invention.

[0023] Figure 4 This is a schematic diagram of the through-hole filling in the substrate glass of an ultra-narrow bottom bezel display panel according to the present invention.

[0024] Figure 5 This is a schematic diagram of the back side of the substrate glass in a display panel with an ultra-narrow bottom bezel according to the present invention.

[0025] Figure 6 This is a schematic diagram of a second solder pad being provided on the back of the substrate glass in a display panel with an ultra-narrow bottom bezel according to the present invention.

[0026] Figure 7 for Figure 6 A magnified view of region A in the middle.

[0027] Figure 8 This is a schematic diagram showing the first pad of the flip-chip thin film layer in a display panel with an ultra-narrow bottom bezel according to the present invention.

[0028] Figure 9 for Figure 8 A magnified view of region B in the middle.

[0029] Figure Labels

[0030] 1. Cover glass

[0031] 2 Ink layer

[0032] 3 Optical transparent adhesive

[0033] 4. Polarizing film

[0034] 5. Substrate Glass

[0035] 51 Preset Area

[0036] 6. Insulating adhesive backing layer

[0037] 7 foam layers

[0038] 8 Support pads

[0039] 9. Driver chip

[0040] 10 Flexible substrates

[0041] 11 Double-sided adhesive layer

[0042] 12. Flip-chip thin film layer

[0043] 13 Through holes

[0044] 14 Conductive Filling Dielectric

[0045] 15 First pad

[0046] 16 Second pad Detailed Implementation

[0047] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0048] The use of terms such as "first," "second," and similar terms in the specific description does not indicate any order, quantity, or importance, but is merely used to distinguish different components. Furthermore, in the description of this invention, terms such as "upper," "lower," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention.

[0049] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features in different embodiments can be combined with each other.

[0050] Figure 1 This is a schematic diagram of a display panel with an ultra-narrow bottom bezel, based on existing technology. Figure 1 As shown, a prior art ultra-narrow bottom bezel display panel includes, in sequence, a cover glass 1 (surrounded by an ink layer 2), an optically transparent adhesive 3, a polarizer 4, a substrate glass 5, an insulating backing layer 6, a foam layer 7, a support pad 8, a double-sided adhesive layer 11, and a driver chip 9. A flip-chip thin film layer 12 supports the driver chip 9 and is bent to electrically connect a flexible substrate 10, the pins of the driver chip 9, and the pads of the substrate glass 5. Figure 1 As shown, current mainstream high-resolution display panels (such as those using low-temperature polycrystalline silicon technology) typically use a flip-chip thin film as the carrier for the driving integrated circuit, and directly connect the flip-chip thin film to pre-fabricated bonding pads on the lower edge of the substrate glass using an anisotropic conductive adhesive film bonding process. This connection area is usually referred to as the "bonding area". To ensure the reliability and connection strength of the bonding process, these bonding pads need to have sufficient length, typically greater than 300 micrometers (see [link to documentation]). Figure 1 (D in the text). Furthermore, the bonding process requires high temperatures and pressures (typically exceeding 160°C). The outermost polarizer of the display panel is highly sensitive to high temperatures, which can cause deformation, blistering, or malfunction. Therefore, to prevent high-temperature damage to the polarizer during bonding, the bonding pad area must maintain a sufficient safety distance from the lower edge of the polarizer; this distance typically needs to be greater than 200 micrometers (see D). Figure 1 (C) The pad length and clearance distance alone already occupy more than 500 micrometers of width. This is further increased by considering the flip-chip layer itself and the space required for its bending (the protrusion distance is typically around 400 micrometers, see [reference]). Figure 1 Factors such as the E in the equation, the cutting tolerance of the substrate glass edge, and the width of the sealant ultimately result in the total width of the bottom bezel in traditional solutions typically exceeding 1000 micrometers, generally reaching 1200 micrometers or even wider. Figure 1In the diagram, A represents the area between the effective display area and the visible area, and B represents the area between the visible area and the edge of the polarizer area. In comparison, the left, right, and top bezels can all be within 800 micrometers. Figure 1 The sum of the lengths of the three regions C, D, and E is approximately 1100 micrometers. This results in the bottom bezel width F being significantly greater than the widths of the left, right, and top bezels, causing an imbalance in the bezel widths on all four sides of the display panel. The bottom bezel is noticeably wider, which affects the overall aesthetics and further improvement of the screen-to-body ratio.

[0051] For display panels using flexible substrates, although the substrate itself can be bent, which helps to reduce the space of certain mechanical structures, the bottom bezel is usually around 1000 micrometers due to the limitations of its dam width and the distance from the dam to the thin film encapsulation layer, which also faces the problem of an excessively wide bottom bezel.

[0052] The industry has explored various approaches to reduce the bottom bezel. One approach is to integrate the driver IC directly onto the substrate glass, but this significantly increases the complexity and cost of the substrate glass manufacturing process and poses challenges to the driving capabilities of high-resolution, high-refresh-rate panels. Another approach is to shorten the length of the bonding pads, but this directly reduces the mechanical strength and electrical reliability of the bonding connection, posing a higher risk in harsh product operating environments. A further solution involves using more precise bonding equipment and materials, but this significantly increases production costs. Additionally, some solutions attempt to move the bonding area to the side or back, but this often requires more complex multi-layer wiring designs and special packaging structures, further increasing design and manufacturing complexity.

[0053] Figure 2 This is a schematic diagram of a display panel with an ultra-narrow bottom bezel according to the present invention. Figure 3 This is a schematic diagram of the through-hole arrangement in the substrate glass of a display panel with an ultra-narrow bottom bezel according to the present invention. Figure 4 This is a schematic diagram illustrating the through-hole filling of the substrate glass in a display panel with an ultra-narrow bottom bezel according to the present invention. Figure 2 , 3As shown in Figure 4, the present invention provides a display panel with an ultra-narrow bottom bezel. The bottom bezel area of ​​the display panel includes: a cover glass 1; an optically transparent adhesive 3 disposed on one side of the cover glass 1; a polarizer 4 disposed on the side of the optically transparent adhesive 3 away from the cover glass 1; a substrate assembly disposed on the side of the polarizer 4 away from the optically transparent adhesive 3, the substrate assembly including a substrate glass 5, the bottom bezel area of ​​the substrate glass 5 having a plurality of through holes 13 penetrating its thickness direction, the through holes 13 being filled with a conductive filling medium 14; and a first pad array disposed on the side of the substrate glass 5 away from the cover glass 1. On one side of the polarizer 4, the first pad array includes a plurality of first pads 15, each of which is electrically connected to the conductive filling medium 14 of the via 13; a driver chip 9 is disposed on the side of the substrate glass 5 away from the polarizer 4; and a flip-chip thin film layer 12, on which the driver chip 9 is carried, and a second pad array is provided at one end of the flip-chip thin film layer 12, the second pad array including a plurality of second pads 16, the flip-chip thin film layer 12 being electrically connected to a flexible substrate 10 and the pins of the driver chip 9, and the first pad array and the second pad array being correspondingly bonded.

[0054] In this invention, the cover glass 1 serves as the outermost protective structure of the display panel. An ink layer 2 is coated around its perimeter in the non-display area to conceal the non-display structure in the lower bezel area, enhancing the product's aesthetic appearance. An optically transparent adhesive 3 is disposed on the side of the cover glass 1 facing the substrate glass 5, used to firmly bond the cover glass 1 to the polarizer 4, while ensuring high light transmittance in the laminated structure. The polarizer 4 is disposed on the side of the optically transparent adhesive 3 away from the cover glass 1, i.e., between the optically transparent adhesive 3 and the substrate glass 5. The polarizer 4 prevents the metal electrodes from reflecting ambient light, ensuring a clear display effect in bright environments. The substrate glass 5, as the core component of the substrate assembly, typically has display functional layers such as thin-film transistor arrays, pixel electrodes, liquid crystal layers, or organic light-emitting layers fabricated on it. The core improvement of this invention lies in the provision of multiple through-holes 13 penetrating the thickness direction in the lower bezel area of ​​the substrate glass 5, with conductive filling medium 14 filling the through-holes 13. These vias 13 replace the bonding pads on the front side of the substrate glass 5 in the traditional solution, guiding the traces on the front side of the substrate glass 5 to the back side of the substrate glass 5 through the conductive filling medium 14 within the vias 13. Because the vias 13 have small apertures and are densely packed, the spacing between the pads in the first pad array is also correspondingly small, making direct alignment and bonding with the flip-chip thin film layer 12 difficult. Therefore, the first pads 15 are located on the back side of the substrate glass 5 (i.e., the side facing away from the polarizer 4) and are electrically connected to the conductive filling medium 14 within the vias 13. The flip-chip thin film layer 12 carries the driver chip 9, and a second pad 16 at one end of the layer corresponds to and bonds with the first pad 15, thereby achieving electrical connection between the driver chip 9 and the internal traces of the display panel, reducing the alignment difficulty in subsequent bonding processes. The flip-chip thin film layer 12 is also electrically connected to the flexible substrate 10 to receive external signals. Through the above structure, the driving signal output by the driving chip 9 is sequentially transmitted to the display functional layer on the front side of the substrate glass 5 via the flip-chip thin film layer 12, the first pad 15, the second pad 16, and the conductive filling medium 14 in the via 13, thereby driving the display panel to work normally. This invention mainly achieves the guidance of the traces on the front side of the substrate glass 5 to the back side by setting a through-hole 13 that penetrates the thickness direction on the substrate glass 5 and filling it with the conductive filling medium 14. This allows the flip-chip thin film layer 12 to be bonded on the back side of the substrate glass 5, thereby transferring the bonding area from the front side to the back side of the substrate glass 5. This structure completely changes the traditional design mode in display panels where the flip-chip film must be bonded at the front edge, avoiding the occupation of the bottom bezel width by the bonding pad length and polarizer clearance distance, and eliminating the need for bending the flip-chip film, thus significantly reducing the width of the bottom bezel.

[0055] In this invention, by providing a through-hole 13 in the lower frame region of the substrate glass 5, the bonding pads originally located on the front side of the substrate glass 5 are transferred to the back side, completely eliminating the front bonding pads in the lower frame region and eliminating the contribution of the bonding pad length (typically greater than 300 micrometers) to the width of the lower frame. Since the bonding process is transferred to the back side of the substrate glass 5, the polarizer 4 no longer needs to avoid the bonding area, eliminating the contribution of the safety distance (typically greater than 200 micrometers) between the polarizer 4 and the bonding area to the width of the lower frame. The flip-chip thin film layer 12 is bonded on the back side of the substrate glass 5, unlike conventional solutions. By bending the film to the front of the substrate glass 5, the contribution of the bending protrusion of the flip-chip thin film layer 12 (typically about 400 micrometers) to the width of the bottom bezel is eliminated. The bonding arrangement of the first pad array and the second pad array enables the dense array of vias 13 to achieve a reliable electrical connection with the flip-chip thin film layer 12, reducing the alignment difficulty of the bonding process and improving the production yield. In summary, the bottom bezel width of the display panel of the present invention can be reduced to less than 800 micrometers, achieving a width that is basically the same as the left, right and top bezels, thereby achieving a narrow bezel design with equal width on all four sides, significantly improving the aesthetic appearance and screen ratio of the product.

[0056] In a preferred embodiment, the aperture of the via 13 is 15 to 25 micrometers, and the center-to-center distance between adjacent vias 13 is 30 to 50 micrometers. In this embodiment, the aperture of the via 13 is limited to the range of 15 to 25 micrometers. This aperture range is determined by comprehensively considering the laser processing accuracy, electroplating filling process capability, and electrical conductivity requirements. If the aperture is less than 15 micrometers, the difficulty of laser processing increases significantly, and defects such as insufficient filling or voids are prone to occur during electroplating filling, affecting the conductivity reliability of the via 13. If the aperture is greater than 25 micrometers, the width of the lower border area occupied by the via 13 increases, which is not conducive to achieving the design goal of an ultra-narrow lower border. The center-to-center distance between adjacent vias 13 is limited to the range of 30 to 50 micrometers. This center-to-center distance range is an optimized choice that minimizes the width of the lower border occupied by the via 13 array while ensuring the electrical insulation performance between adjacent vias 13. If the hole center distance is less than 30 micrometers, the wall thickness of the substrate glass 5 between adjacent vias 13 is too thin, which can easily lead to cracks or damage during laser processing and subsequent processes, and electrical breakdown may occur between adjacent vias 13. If the hole center distance is greater than 50 micrometers, the arrangement density of the via array 13 is insufficient, and a sufficient number of vias 13 cannot be arranged within the limited width of the lower bezel to meet the driving signal transmission requirements of the high-resolution display panel. This embodiment limits the hole diameter and hole center distance of the vias 13 to the above-mentioned preferred range, while ensuring the processing quality, conductivity reliability and electrical insulation performance of the vias 13, and minimizes the width of the lower bezel occupied by the via array 13, providing a reliable process parameter guarantee for achieving a lower bezel width of less than 800 micrometers.

[0057] In a preferred embodiment, adjacent rows of through holes 13 are staggered along the thickness direction of the substrate glass 5. (See reference...) Figure 3The axis M of the through holes 13 in the upper row is perpendicular to the lower edge of the substrate glass 5, and the axis N of the through holes 13 in the lower row is perpendicular to the lower edge of the substrate glass 5. The axes M and N are not collinear and are staggered. In this embodiment, when the through holes 13 are arranged in multiple rows in the lower edge region of the substrate glass 5, the through holes 13 in adjacent rows are staggered along the thickness direction of the substrate glass 5 (i.e., the width direction of the substrate glass 5, from the edge of the display area to the edge of the substrate glass 5). The so-called staggered arrangement means that the through holes 13 in adjacent rows are staggered by a certain distance along the extension direction (i.e., the length direction) of the edge of the substrate glass 5, rather than being completely aligned. This staggered arrangement has many beneficial effects. First, the staggered arrangement means that the through holes 13 in adjacent rows are not completely overlapping in the width direction of the substrate glass 5, so that more rows of through holes 13 can be arranged within the limited width of the lower edge, or the center distance between adjacent through holes 13 can be increased with the same number of rows, reducing the electrical interference and breakdown risk between adjacent through holes 13. Secondly, the staggered arrangement helps improve the mechanical strength of the substrate glass 5 in the lower frame area. If the through holes 13 in adjacent rows are perfectly aligned, a continuous "hole band" will be formed in the width direction of the substrate glass 5, resulting in a significant reduction in the mechanical strength of the substrate glass 5 in this area, making it prone to breakage during subsequent processes or use. The staggered arrangement, however, causes the through holes 13 in adjacent rows to be staggered in the length direction, avoiding the formation of a continuous "hole band" and thus maintaining the mechanical strength of the lower frame area. Thirdly, the staggered arrangement facilitates the implementation of the electroplating filling process, allowing the electroplating solution to be more evenly distributed in each through hole 13 during the filling process, reducing filling defects. The technical effect of this embodiment is that, through the staggered arrangement of adjacent rows of through holes 13, a high-density arrangement of through holes 13 is achieved within the limited width of the lower frame, while ensuring the mechanical strength of the lower frame area and the quality of electroplating filling.

[0058] Figure 5 This is a schematic diagram of the back side of the substrate glass in a display panel with an ultra-narrow bottom bezel according to the present invention. Figure 6 This is a schematic diagram of a second solder pad being provided on the back of the substrate glass in a display panel with an ultra-narrow bottom bezel according to the present invention. Figure 7 for Figure 6 A magnified view of region A in the middle. Figure 8 This is a schematic diagram showing the first pad of the flip-chip thin film layer in a display panel with an ultra-narrow bottom bezel according to the present invention. Figure 9 for Figure 8 A magnified view of region B. In a preferred embodiment, refer to... Figures 5 to 9As shown, the first pad 15 is a first strip-shaped pad extending along the length direction of the substrate glass 5 and staggered along the width direction; the second pad 16 is a second strip-shaped pad extending along the length direction of the substrate glass 5 and staggered along the width direction. Each second strip-shaped pad is independently bonded to its corresponding first strip-shaped pad. The first arrangement pattern of the first pad array overlaps with the second arrangement pattern of the second pad array, that is, the first pad 15 and the second pad 16 correspond to each other in spatial position, and each second strip-shaped pad is independently bonded to its corresponding first strip-shaped pad. This design of strip-shaped pads and staggered arrangement is to solve the alignment difficulty caused by the high density of the via 13 array and the small pad spacing. Because the via 13 has a small aperture (about 20 micrometers) and a small hole spacing (about 40 micrometers), it is extremely difficult to directly perform bonding and alignment of flip-chip films on such a dense array. By setting the first pad 15 as a strip pad, the electrical connection of the dense via array can be extended to a larger pad area (the area of ​​the strip pad is much larger than that of the via, which helps reduce the difficulty of bonding and enhances the electrical connection performance). Then, it is bonded to the second pad 16 on the flip-chip thin film layer 12, thereby reducing the bonding alignment difficulty between the flip-chip thin film layer 12 and the substrate glass 5 and improving the yield of the bonding process. The strip pad and staggered arrangement design allows each second strip pad to be bonded independently to its corresponding first strip pad, avoiding mutual interference during the bonding process and providing greater alignment tolerance for the bonding process.

[0059] In a preferred embodiment, the substrate glass 5 is divided into a preset region 51 corresponding to the effective display area (AA area). The first strip pad does not stop at the non-display area of ​​the lower bezel, but starts from the opening edge or sidewall of the via 13 and extends in a straight line along the surface of the substrate glass 5 toward the preset region 51. Its end portion away from the via 13 extends into the interior of the preset region 51, that is, it crosses the boundary line of the effective display area and is located below the pixel array or data line trace. This allows for a longer strip pad without occupying the bezel width, reducing the difficulty of bonding and enhancing connection stability. This embodiment significantly reduces the width of the lower bezel. By extending the first strip pad into the interior of the effective display area, the substrate space below the AA area is effectively utilized to accommodate the trace length that would otherwise have to be laid in the non-display area. This significantly shortens the non-display area width required for the lower bezel, providing key structural support for achieving an ultra-narrow lower bezel. Furthermore, it helps reduce signal transmission delay (RC delay). The first strip pad extends directly into the preset area, greatly shortening the signal transmission path between the via and the pixel electrodes or data lines in the display area. This effectively reduces wire resistance and parasitic capacitance, ensuring the synchronization of high-frequency drive signal transmission between the panel edge and the central area, and improving overall display uniformity and picture quality. It also enhances connection reliability and process yield. The end of the pad enters the effective display area and forms a large overlap or connection with the internal lines of the array layer, increasing the actual contact area and adhesion strength. This effectively avoids pad breakage or poor contact caused by excessively narrow bezels, while also reducing the risk of stress concentration caused by differences in the coefficient of thermal expansion, significantly improving the long-term reliability and manufacturing yield of the panel.

[0060] In a preferred embodiment, continue to refer to Figure 3 and 4The via 13 has a chemically plated copper layer (not shown in the figure) on its wall and an electroplated copper layer (not shown in the figure) covering the outer wall of the chemically plated copper layer. The conductive filling medium 14 is electroplated copper, and the on-resistance of each via 13 is less than or equal to 50 milliohms. In this embodiment, the metallization process of the via 13 adopts a combination of chemical copper plating and electroplating. First, a chemically plated copper layer is formed on the wall of the via 13 formed by laser processing using a chemical copper plating process. Chemical copper plating is a chemical deposition method that does not require an external current. It can uniformly deposit a thin copper layer on the wall of the insulating substrate glass 5, providing a conductive seed layer for subsequent electroplating. Due to the small aperture and large aspect ratio of the via 13, chemical copper plating can ensure the uniform formation of a conductive seed layer at various parts of the hole wall (including the top, bottom, and middle of the hole wall), overcoming the defect that electroplating cannot be directly performed on the insulating surface. Then, based on the electroless copper plating layer, an electroplated copper layer is applied to the outer wall of the electroless copper plating layer through an electroplating process, ultimately filling the entire through-hole 13 to form a conductive filling medium 14, namely, electroplated filling copper. The electroplated filling copper completely fills the internal space of the through-hole 13, creating a low-resistance electrical conduction path between the front and back openings of the through-hole 13. This embodiment sets a quality requirement of less than or equal to 50 milliohms for the on-resistance of each through-hole 13. This on-resistance value is determined by comprehensively calculating the aperture and depth of the through-hole 13, the resistivity of the electroplated filling copper, and the magnitude of the driving current in actual applications. If the on-resistance is greater than 50 milliohms, a large voltage drop and heat generation will occur on the through-hole 13 under high current driving, affecting the display quality and reliability of the display panel. This embodiment achieves low-resistance and high-reliability electrical conduction in the through-holes 13 with small apertures and large aspect ratios through a composite process of chemical copper plating and electroplating copper filling. The conduction resistance of each through-hole 13 is less than or equal to 50 milliohms, ensuring signal integrity and low power consumption during the transmission of drive signals from the front of the panel to the back.

[0061] In a preferred embodiment, an ink layer 2 is further included. The ink layer 2 is disposed in the peripheral non-display area of ​​the cover glass 1 facing the optically transparent adhesive 3. The orthographic projection of the ink layer 2 on the substrate glass 5 covers the area where the through-hole 13 is located. In this embodiment, the ink layer 2 is typically made of black or dark ink material. Its function is to shield various structures in the peripheral non-display area of ​​the display panel, including wiring, driving circuits, through-hole 13, etc., making these structures invisible from the front of the display panel, thereby enhancing the aesthetic appearance of the product. That is, when viewed from the front of the display panel, the area where the through-hole 13 is located is completely shielded by the ink layer 2, and the user cannot see the existence of the through-hole 13. This design has the following significant advantages: First, although the through-hole 13 is located in the lower bezel area of ​​the substrate glass 5, its visibility from the front would severely affect the appearance quality of the display panel. The ink layer 2 effectively solves this problem. Second, the ink layer 2 covers the entire area where the through-hole 13 is located, meaning that the through-hole 13 can be placed closer to the display area without worrying about its visibility affecting the appearance, which is beneficial for further reducing the width of the lower bezel. Third, the ink layer 2 also prevents light leakage from the edge of the cover glass 1, further improving the display quality. The technical effect of this embodiment is that by completely covering the area where the through-hole 13 is located with the ink layer 2, the through-hole 13 is visually hidden while ensuring the ultra-narrow lower bezel design, thus improving the product's aesthetics and display quality.

[0062] In a preferred embodiment, the polarizer 4 covers the area where the through-hole 13 is located in the substrate glass 5. In this embodiment, the polarizer 4 not only covers the display area of ​​the substrate glass 5, but also extends downwards to cover the area where the through-hole 13 is located in the substrate glass 5. This is completely different from the conventional approach where the polarizer 4 needs to avoid the bonding area (usually requiring a safety distance of more than 200 micrometers). In this invention, since the bonding process is transferred to the back side of the substrate glass 5, the through-hole 13 area on the front side of the substrate glass 5 no longer needs to undergo a high-temperature bonding process, therefore the polarizer 4 no longer needs to avoid the through-hole 13 area. The polarizer 4 can directly cover the area where the through-hole 13 is located, or even cover the entire surface of the substrate glass 5 (except for necessary edge cutting areas). The benefits of this design are significant: First, it eliminates the safety distance (typically greater than 200 micrometers) between the polarizer 4 and the bonding area in traditional solutions, directly reducing the width of the bottom bezel; second, the polarizer 4 covers the area where the through-hole 13 is located, further shielding the through-hole 13 from the front, and working together with the ink layer 2 to ensure that the through-hole 13 is completely invisible from the front of the display panel; third, the increased coverage area of ​​the polarizer 4 helps improve the overall structural strength and impact resistance of the display panel. The technical effect of this embodiment is that by covering the area where the through-hole 13 is located with the polarizer 4, the width loss caused by the polarizer 4 needing to avoid the bonding area in traditional solutions is eliminated, further reducing the width of the bottom bezel, while simultaneously enhancing the shielding effect of the through-hole 13 and the structural strength of the display panel.

[0063] In a preferred embodiment, the bottom bezel width of the display panel is less than 800 micrometers. In this embodiment, the bottom bezel width of the display panel is limited to less than 800 micrometers. As mentioned above, the bottom bezel width of conventional solutions is typically greater than 1000 micrometers, generally 1200 micrometers or even wider. This invention achieves a significant reduction in the bottom bezel width through a series of structural improvements. Specifically, by replacing the front bonding pads with through-holes 13, the contribution of the bonding pad length (greater than 300 micrometers) is eliminated; by transferring the bonding process to the back side of the substrate glass 5, the contribution of the safety distance (greater than 200 micrometers) required to avoid the bonding area of ​​the polarizer 4 is eliminated; and by bonding the flip-chip thin film layer 12 to the back side of the substrate glass 5 without bending, the contribution of the bending protrusion of the flip-chip thin film layer 12 (approximately 400 micrometers) is eliminated. These three improvements reduce the bottom bezel width by approximately 900 micrometers. Even considering other factors such as the cutting tolerance of the substrate glass 5 edge and the width of the sealant, the bottom bezel width of this invention can still be controlled within 800 micrometers. This width is essentially the same as the current widths of the left, right, and top bezels (which can typically be kept below 800 micrometers), thus achieving a balanced bezel width on all four sides of the display panel and achieving a truly "equal width on all four sides" narrow bezel design. The technical effect of this embodiment is that it achieves an ultra-narrow bottom bezel design with a bottom bezel width of less than 800 micrometers, making the bezel widths on all four sides of the display panel more consistent, significantly improving the screen-to-body ratio and the aesthetic appeal of the product.

[0064] In a preferred embodiment, the lower border region of the substrate glass 5 does not have front-side bonding pads. The second pad array of the flip-chip thin film layer 12 is bonded to the first pad array on the back side of the lower border region of the substrate glass 5 via a low-temperature bonding process. This is completely different from the conventional approach where bonding pads with a length greater than 300 micrometers are required at the lower edge of the substrate glass 5. In this invention, the front side of the lower border region of the substrate glass 5 (i.e., the side facing the polarizer 4) does not have conventional front-side bonding pads. The second pad 16 of the flip-chip thin film layer 12 is bonded to the first pad 15 on the back side of the substrate glass 5 via a low-temperature bonding process. Since the bonding process is performed on the back side of the substrate glass 5, away from the polarizer 4, conventional temperature or even low-temperature bonding processes can be used without worrying about thermal damage to the polarizer 4. In this embodiment, the lower border region of the substrate glass 5 does not have front-side bonding pads, completely eliminating the occupation of the lower border width by the length of the bonding pads in the conventional approach. The low-temperature bonding process is performed on the back side of the substrate glass 5, which will not cause thermal damage to the polarizer 4 located on the front side of the substrate glass 5. Therefore, the polarizer 4 can extend to cover the area where the via 13 is located, further reducing the width of the bottom bezel. At the same time, back-side bonding also eliminates the need for bending of the flip-chip film layer 12, thus eliminating the influence of the amount of flip-chip film bending protrusion on the width of the bottom bezel.

[0065] In one specific embodiment of the present invention, a display device is provided, including the aforementioned ultra-narrow bottom bezel display panel. In this embodiment, the display device can be a smartphone, tablet computer, laptop computer, television, monitor, in-vehicle display device, wearable device, or any other electronic device with display functionality. The core component of this display device is the aforementioned ultra-narrow bottom bezel display panel. Due to the use of an ultra-narrow bottom bezel display panel, this display device has the following advantages: First, the screen-to-body ratio is significantly improved, providing a larger display area within the same overall size, or achieving a smaller overall size within the same display area; second, the bezel widths on all four sides are balanced, resulting in a more refined and modern appearance, conforming to the aesthetic trends of high-end consumer electronics products; third, the bottom bezel width is less than 800 micrometers, achieving a truly "full-screen" visual effect; fourth, the drive signal transmission of the display panel is reliable, resulting in excellent display quality. The technical effect of this embodiment is that it provides a display device with an ultra-narrow bottom bezel, high screen-to-body ratio, and excellent display quality, meeting consumers' demand for full-screen display devices.

[0066] In this embodiment, the bottom bezel width of the display panel is less than 800 micrometers. The bottom bezel width L mainly includes: the G region is the AA-VA region (approximately 150 μm wide) between the effective display area and the visible area; the H region is the VA-POL region (approximately 250 μm wide) between the visible area and the edge of the polarizer area; and the I region is the POL-Panel OD region (approximately 110 μm wide) between the edge of the polarizer area and the edge of the substrate glass 5. Because this embodiment eliminates the front bonding pads (approximately 300 micrometers in conventional solutions), the safety distance for avoiding the bonding area of ​​the polarizer 4 (approximately 200 micrometers in conventional solutions), and the bending protrusion of the flip-chip thin film layer 12 (approximately 400 micrometers in conventional solutions), the bottom bezel width of this embodiment is significantly reduced compared to conventional solutions, and can be controlled within 800 micrometers.

[0067] The following is combined with Figures 2 to 9 The signal transmission path and working principle of the display panel in this implementation scheme are explained in detail.

[0068] When the display panel is working normally, the system motherboard transmits display data and control signals to the flip-chip thin film layer 12 via the flexible substrate 10. After receiving these signals, the driver chip 9 on the flip-chip thin film layer 12 performs internal timing control and signal driving processing to generate drive signals for driving each pixel of the display panel. These drive signals are output from the pins of the driver chip 9 and transmitted via the internal traces of the flip-chip thin film layer 12 to the bonding connection between the flip-chip thin film layer 12 and the first pad 15. Since the flip-chip thin film layer 12 uses a low-temperature bonding process to bond the first pad 15 to the corresponding second pad 16, the drive signals are transmitted from the flip-chip thin film layer 12 to the second pad 16. Each second pad 16 is electrically connected to the conductive filling medium 14 in the corresponding via 13, and the drive signals are transmitted from the first pad array to the conductive filling medium 14 in the via 13. The conductive filling medium 14 in the via 13 transmits the drive signals from the back side of the substrate glass 5 to the front side of the substrate glass 5, i.e., the front opening of the via 13. The traces on the front side of the substrate glass 5 are connected to the front opening of the via 13. The driving signal is transmitted from the front opening of the via 13 to the traces on the front side of the substrate glass 5, and then to each pixel electrode in the display area, driving the liquid crystal molecules to deflect or the organic light-emitting material to emit light, thereby realizing the display of the image.

[0069] In the aforementioned signal transmission path, the conductive filling medium 14 within the via 13 plays a crucial "bridge" role, enabling low-resistance, high-reliability transmission of the drive signal from the back side to the front side of the substrate glass 5. The on-resistance of each via 13 is less than or equal to 50 milliohms, ensuring signal integrity and low power consumption during transmission. The bonding connections of the first and second pad arrays serve as "transfer" and "expansion" mechanisms, reducing the bonding difficulty between the substrate glass 5 and the flip-chip thin film layer 12.

[0070] The improvements and beneficial effects of this implementation scheme compared to the prior art are as follows: First, this invention, by providing a through-hole 13 in the lower border region of the substrate glass 5, transfers the bonding pads originally located on the front side of the substrate glass 5 to the back side, completely eliminating the front bonding pads in the lower border region and eliminating the contribution of the bonding pad length (typically greater than 300 micrometers) to the lower border width. In conventional solutions, to ensure the reliability and connection strength of the bonding process, the bonding pads need to have sufficient length, typically greater than 300 micrometers, which is one of the important sources of lower border width. This invention completely eliminates this source of width by replacing the bonding pads with through-holes 13.

[0071] Secondly, this invention transfers the bonding process to the back side of the substrate glass 5. The polarizer 4 no longer needs to avoid the bonding area, eliminating the contribution of the safety distance (typically greater than 200 micrometers) between the polarizer 4 and the bonding area to the width of the lower bezel. In conventional solutions, due to the high bonding process temperature (typically exceeding 160°C), the polarizer 4 is very sensitive to high temperatures. Therefore, the bonding pad area must maintain a sufficient safety distance from the lower edge of the polarizer 4, typically greater than 200 micrometers. This invention transfers the bonding process to the back side, freeing the polarizer 4 from the threat of high bonding temperatures, allowing it to directly cover the area where the via 13 is located, thus eliminating this safety distance.

[0072] Third, the flip-chip thin film layer 12 is bonded to the back side of the substrate glass 5, eliminating the need for bending it to the front side of the substrate glass 5 as in conventional solutions. This eliminates the contribution of the bending protrusion of the flip-chip thin film layer 12 (typically about 400 micrometers) to the width of the lower bezel. In conventional solutions, the flip-chip thin film layer 12 needs to be bent from the back side of the substrate glass 5 to the front side, and the bent portion occupies additional protruding space, further increasing the width of the lower bezel. In this invention, the flip-chip thin film layer 12 is directly bonded to the back side without bending, eliminating this source of width.

[0073] Fourth, the bonding connection of the first pad array and the second pad array enables the dense array of vias 13 to achieve a reliable electrical connection with the flip-chip thin film layer 12, reducing the alignment difficulty of the bonding process and improving the production yield.

[0074] Fifth, the through-hole 13 is formed using picosecond or femtosecond laser cold processing, which can achieve high-precision through-holes 13 with a diameter of 15 to 25 micrometers and a center-to-center distance of 30 to 50 micrometers, and the hole accuracy can reach ±3 micrometers. This high-precision laser processing method ensures the quality and consistency of the through-hole 13, providing a good foundation for the subsequent electroplating filling process.

[0075] Sixth, the metallization of via 13 employs a combination of electroless copper plating and electroplating, achieving low resistance and high reliability electrical conductivity in the via 13 with its small aperture and large aspect ratio. Electroless copper plating ensures the uniform formation of a conductive seed layer on the insulating hole wall, while electroplating achieves complete filling of via 13, with the conductivity of each via 13 being less than or equal to 50 milliohms.

[0076] Seventh, the orthographic projection of the ink layer 2 onto the substrate glass 5 covers the area where the through hole 13 is located, and the polarizer 4 also covers the area where the through hole 13 is located. The two work together to ensure that the through hole 13 is completely invisible from the front of the display panel, thus enhancing the aesthetic appearance of the product.

[0077] Eighth, taking into account the above improvements, the bottom bezel width of the display panel of the present invention can be reduced to less than 800 micrometers, achieving a width that is basically the same as the left, right, and top bezels, thereby realizing a narrow bezel design with equal width on all four sides, significantly improving the product's aesthetic appearance and screen ratio.

[0078] In summary, this invention enables ultra-narrow bottom bezel display panels by connecting the traces on the front and back sides of the substrate, allowing the flip-chip thin film layer to be bonded to the back side. This reduces the bonding area and eliminates the impact of bending protrusion on the flip-chip thin film layer, resulting in a bottom bezel that can be reduced to within 800 micrometers. Furthermore, the combination of the first pad array, the second pad array, and the via array allows for dense through-wire routing, fully utilizing the edge space of the substrate glass without bending the traces. This reduces the soldering difficulty with the flip-chip thin film layer and improves yield. The display panel and display device of this invention can be widely used in various consumer electronics products, particularly suitable for portable devices such as smartphones and tablets that require high screen-to-body ratios and aesthetic appeal.

[0079] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A display panel with an ultra-narrow bottom bezel, characterized in that, The lower border area of ​​the display panel includes: A cover glass (1); An optically transparent adhesive (3) is disposed on one side of the cover glass (1); A polarizer (4) is disposed on the side of the optically transparent adhesive (3) away from the cover glass (1); A substrate assembly is disposed on the side of the polarizer (4) away from the optical transparent adhesive (3). The substrate assembly includes a substrate glass (5). The lower frame area of ​​the substrate glass (5) is provided with a plurality of through holes (13) penetrating its thickness direction. The through holes (13) are filled with a conductive filling medium (14). A first pad array is disposed on the side of the substrate glass (5) away from the polarizer (4). The first pad array includes a plurality of first pads (15), each of which is electrically connected to the conductive filling medium (14) of the through hole (13). A driver chip (9) is disposed on the side of the substrate glass (5) opposite to the polarizer (4); and A flip-chip thin film layer (12) is provided, on which the driver chip (9) is carried. A second pad array is provided at one end of the flip-chip thin film layer (12), the second pad array includes a plurality of second pads (16). The flip-chip thin film layer (12) is electrically connected to a flexible substrate (10) and the pins of the driver chip (9) respectively. The first pad array and the second pad array are correspondingly bonded.

2. The display panel with an ultra-narrow bottom bezel according to claim 1, characterized in that, The aperture of the through hole (13) is 15 micrometers to 25 micrometers, and the center distance between adjacent through holes (13) is 30 micrometers to 50 micrometers.

3. The display panel with an ultra-narrow bottom bezel according to claim 1, characterized in that, The through holes (13) are arranged in multiple rows in the lower frame region of the substrate glass (5), and the through holes (13) in adjacent rows are staggered along the thickness direction of the substrate glass (5).

4. The display panel with an ultra-narrow bottom bezel according to claim 3, characterized in that, The first pad (15) is a first strip-shaped pad that extends along the length direction of the substrate glass (5) and is staggered along the width direction; The second pad (16) is a second strip pad that extends along the length direction of the substrate glass (5) and is staggered along the width direction. Each second strip pad is independently bound to the corresponding first strip pad. The first arrangement pattern of the first pad array overlaps with the second arrangement pattern of the second pad array.

5. The display panel with an ultra-narrow bottom bezel according to claim 4, characterized in that, The substrate glass (5) has a preset area (51) corresponding to the effective display area, and the first strip pad extends from the through hole (13) to the preset area (51) and at least partially enters the preset area (51).

6. The display panel with an ultra-narrow bottom bezel according to claim 1, characterized in that, The wall of the through hole (13) is provided with a chemically plated copper layer, and the conductive filling medium (14) is electroplated copper.

7. The display panel with an ultra-narrow bottom bezel according to claim 1, characterized in that, It also includes an ink layer (2), which is disposed in the peripheral non-display area of ​​the cover glass (1) on the side facing the optically transparent adhesive (3), and the orthographic projection of the ink layer (2) on the substrate glass (5) covers the area where the through hole (13) is located.

8. The display panel with an ultra-narrow bottom bezel according to claim 1, characterized in that, The polarizer (4) covers the area where the through hole (13) is located in the substrate glass (5).

9. The display panel with an ultra-narrow bottom bezel according to claim 1, characterized in that, The lower frame area of ​​the substrate glass (5) is not provided with front bonding pads, and the second pad array of the flip-chip thin film layer (12) is bonded to the first pad array through a low-temperature bonding process.

10. A display device, characterized in that, The display panel includes the ultra-narrow bottom bezel as described in any one of claims 1 to 9.

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