COF structure for narrow-frame display screen

Abstract

The utility model discloses a COF (chip on film) structure for a narrow-frame display screen, which comprises a PI (polyimide) layer, a copper laying layer is arranged on the upper surface of the PI layer, a solder mask is arranged on the upper surface of the copper laying layer, a chip mounting opening is arranged on the solder mask, and a flexible IC (integrated circuit) is arranged in the chip mounting opening. The surface of the IC is provided with a PI protection layer. When the COF structure is assembled, due to the fact that the PI layer, the copper laying layer and the solder mask layer have certain toughness, the anti-bending capacity of the COF structure can be effectively improved, meanwhile, wrapping type effective protection can be formed on the flexible IC, and the COF structure is prevented from being broken. The surface of the IC is provided with a PI protection layer. The edge of the PI protection layer covers the solder mask layer. As the edge of the PI protection layer covers the solder mask layer, the bonding force between the PI protection layer and the solder mask layer can be effectively improved, and meanwhile, the edge of the IC can be protected and prevented from being damaged due to impact.

Description

Technical Field

[0001] The utility model relates to a display device, more specifically, to a COF structure used for a narrow-frame display screen. Background Art

[0002] With the development of full-screen smartphones, the four sides of the display are getting narrower and narrower. In order to make the bottom frame narrower, the current market mainly uses COF structure LCD screens, such as Figure 1 and Figure 2 As shown, this structure is to bind the IC on the glass to the film instead. However, since the film is flexible, in actual application, the IC often breaks during bending and assembly operations.

[0003] Chinese invention patent document CN109491123A discloses a method for manufacturing a narrow-frame display screen, characterized in that the method comprises: step S10: providing a first glass substrate, the first glass substrate comprises a display portion and a non-display portion, and a flexible substrate is coated on the non-display portion; step S20: heating and baking the flexible substrate to form a flexible substrate, the flexible substrate comprises a bending portion and a non-bending portion; step S30: cutting and separating the portion of the non-display portion that is bonded to the bending portion; step S40: bending the bending portion to the side or back of the first glass substrate. The flexible substrate is in the shape of a long strip and is arranged in an array on the first glass substrate. The flexible substrate is polyimide. The step S30 also includes: step S301: forming a thin film transistor layer and a first alignment layer on the first glass substrate in sequence, the first glass substrate, the thin film transistor layer and the first alignment layer constitute an array substrate; step S302: forming a color filter layer and a second alignment layer on the second glass substrate in sequence, the second glass substrate, the color filter layer and the second alignment layer constitute a color filter substrate; step S303: applying frame glue, dripping liquid crystal and vacuum bonding process to the array substrate and the color filter substrate to form a liquid crystal box; step S304: forming a plurality of liquid crystal panels by cutting, biasing and integrated circuit chip bonding process of the liquid crystal box; step S305: cutting and separating the portion of the first glass substrate bonded to the bent portion.

[0004] Obviously, this patent realizes the production of a narrow-border display screen by replacing the non-bendable glass substrate of the non-display part of the first glass substrate and the part connecting the integrated circuit chip with a bendable flexible substrate. This process is complex and costly, and especially cannot solve the problem of chip bending.

[0005] Chinese utility model patent document CN207557899U discloses a narrow-frame touch screen, comprising a cover glass and a sensor substrate stacked in sequence, wherein the sensor substrate comprises a body and a downwardly bent portion connected to both ends of the body, wherein the bent portion is provided with a wiring area; the narrow-frame touch screen also comprises a display screen, wherein a housing space is formed between the bent portion and the body, wherein the display screen is at least partially accommodated in the housing space. The bent portion is perpendicular to the body. Black border regions are provided on both ends of the cover glass; wherein one black border region covers the top of one of the bent portions, and the other black border region covers the top of the other bent portion. The width of the black border region is less than 5 mm. A silk-screen black border is provided in the black border region. The narrow-frame touch screen also comprises an outer frame, wherein the cover glass, the sensor substrate and the display screen are all accommodated in the outer frame; wherein the wiring area is provided on one end of the bent portion close to the outer frame. The narrow-frame touch screen also comprises a flexible circuit board, wherein the flexible circuit board is electrically connected to the sensor substrate through the wiring area. The narrow-frame touch screen further comprises a sensing pattern layer, and the sensing pattern layer is electrically connected to the flexible circuit board through the wiring area. The display screen is an LCD display screen.

[0006] Obviously, the patent reduces the lateral width of the wiring area on the sensor substrate inside the narrow-frame touch screen by setting downwardly bent portions on both ends of the body of the sensor substrate and setting a wiring area on the bent portions, thereby reducing the lateral width of the non-visible area, thereby enabling the touch screen to achieve a narrow-frame effect. This structure is too complicated and similarly cannot solve the problem of chip bending.

[0007] Chinese invention patent document CN109002221A discloses an ultra-narrow frame 3D curved touch screen, an ultra-narrow frame 3D curved touch screen, characterized in that it includes a glass cover plate, a touch screen sensor film, a display screen and an FPC flexible cable stacked in sequence; the touch screen sensor film is directly bent to form a main body in contact with the bottom surface of the display screen and a curved portion on both sides of the display screen; the FPC flexible cable is bound and connected to the control card, and the FPC flexible cable is only wired between the bent portion of the touch screen sensor film and the side of the display screen, without involving the glass cover plate; the display screen is at least partially located in the concave space formed by the bending of the touch screen sensor film. The touch screen sensor film begins to bend along the side of the display screen, the bent portion is perpendicular to the main body, and the minimum curvature radius at the right angle bend is at least 0.5mm. A conductive film surface is provided on one side of the touch screen sensor film, and the nanosilver conductive film surface is located on the side of the touch screen sensor film facing the display screen. The conductive film surface is composed of conductive materials, including nanosilver, ITO, metal grid, graphene, etc. The material of the touch screen sensor film is resistant to bending glass or plastic. The FPC flexible flat cable is divided into several parts and connected in sequence, and is directly bound outside the touch channel to achieve the bending of the FPC flexible flat cable.

[0008] Obviously, the patent shows that the width of the black border of the touch screen can be significantly reduced by directly bending the touch screen sensor film and changing the bending wiring of the FPC flexible cable. However, it also cannot solve the problem of chip bending. Utility Model Content

[0009] Based on this, it is necessary to provide a COF structure for a narrow-frame display screen in response to the above technical problems, comprising a PI layer, a copper layer is provided on the upper surface of the PI layer, a solder resist layer is provided on the upper surface of the copper layer, a chip mounting opening is provided on the solder resist layer, and a flexible IC is provided in the chip mounting opening. A PI protective layer is provided on the surface of the IC. When assembling, since the PI layer, the copper layer and the solder resist layer all have a certain toughness, the bending resistance of the COF structure can be effectively improved. At the same time, it can also form an effective wrapping protection for the flexible IC to prevent the COF structure from breaking. A PI protective layer is provided on the surface of the IC. The edge of the PI protective layer covers the solder resist layer. Since the edge of the PI protective layer covers the solder resist layer, the bonding force between the PI protective layer and the solder resist layer can be effectively improved. At the same time, it can also protect the edge of the IC to prevent it from being damaged by impact.

[0010] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0011] A COF structure for a narrow-border display screen, characterized in that the COF structure for a narrow-border display screen comprises a PI layer, a copper layer is provided on the upper surface of the PI layer, a solder resist layer is provided on the upper surface of the copper layer, a chip mounting opening is provided on the solder resist layer, and a flexible IC is provided in the chip mounting opening.

[0012] As a preferred implementation of the COF structure for a narrow-frame display screen provided by the utility model, a PI protective layer is provided on the surface of the IC.

[0013] As a preferred implementation of the COF structure for a narrow-frame display screen provided by the utility model, the edge of the PI protective layer covers the solder resist layer.

[0014] As a preferred implementation of the COF structure for a narrow-frame display screen provided by the present invention, the thickness of the PI protective layer is greater than that of the solder resist layer.

[0015] As a preferred implementation of the COF structure for a narrow-frame display screen provided by the utility model, the height of the IC is greater than the solder resist layer.

[0016] As a preferred implementation of the COF structure for a narrow-frame display screen provided by the utility model, an insulating isolation cavity is provided around the IC.

[0017] As a preferred implementation of the COF structure for a narrow-frame display screen provided by the utility model, the top of the insulating isolation cavity is wedge-shaped.

[0018] As a preferred implementation of the COF structure for a narrow-frame display screen provided by the utility model, the insulating isolation cavity is filled with insulating resin.

[0019] As a preferred implementation of the COF structure for a narrow-frame display screen provided by the utility model, the insulating resin is a high-temperature resistant insulating resin.

[0020] As a preferred implementation of the COF structure for a narrow-frame display screen provided by the utility model, the insulating resin is a transparent resin.

[0021] Compared with the prior art, the utility model has the following beneficial effects:

[0022] The utility model provides a COF structure for a narrow-frame display screen. When assembled, since the PI layer, the copper layer and the solder resist layer all have a certain toughness, the bending resistance of the COF structure can be effectively improved. At the same time, it can also form an effective wrapping protection for the flexible IC to prevent the COF structure from breaking.

[0023] In addition, a PI protective layer can be provided on the surface of the IC. The edge of the PI protective layer covers the solder resist layer. Since the edge of the PI protective layer covers the solder resist layer, the bonding force between the PI protective layer and the solder resist layer can be effectively improved, and at the same time, the edge of the IC can be protected to prevent it from being damaged by impact.

[0024] In addition, an insulating isolation cavity can be provided on the periphery of the IC. The top of the insulating isolation cavity is wedge-shaped. By using the insulating isolation cavity, the insulation performance of the IC can be effectively improved, the leakage current between the IC and the solder resist layer can be reduced, and the energy consumption can be reduced.

[0025] In addition, the insulating isolation cavity may be filled with an insulating resin. The insulating resin is a high temperature resistant insulating resin. The insulating resin is a transparent resin. By using the insulating resin, the insulation performance of the IC can be further improved, the leakage current between the IC and the solder mask layer can be reduced, and the energy consumption can be reduced. Since the insulating resin is a transparent resin, it is convenient to perform visual inspection or machine inspection on the COF structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the scheme in the utility model, a brief introduction is given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a structural schematic diagram of the COF structure of an existing display screen;

[0028] Figure 2 for Figure 1 A schematic diagram of the COF structure of the display screen in FIG. 1 is another perspective;

[0029] Figure 3 It is a structural schematic diagram of the COF structure for a narrow-frame display screen of the present utility model;

[0030] Figure 4 This is a schematic structural diagram of a COF structure for a narrow-frame display screen of the present invention, which is another embodiment;

[0031] Figure 5 This is a schematic structural diagram of a COF structure for a narrow-frame display screen of the present invention, which is another embodiment;

[0032] Figure 6 This is a schematic structural diagram of a COF structure for a narrow-frame display screen of the present invention, which is another embodiment;

[0033] The markings in the figure are as follows: 1. PI layer; 2. Copper layer; 3. Solder mask layer; 31. Chip mounting opening; 4. IC; 41. Insulation isolation cavity; 5. PI protective layer; 6. Insulation resin. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0035] As described in the background technology, in the prior art, for smart phones, with the development of full-screen smart phones, the four sides of the display screen are getting narrower and narrower. In order to make the bottom frame narrower, the current market mainly uses a COF structured LCD display, such as Figure 1 and Figure 2 As shown, this structure is to bind the IC on the glass to the film instead. However, since the film is flexible, in actual application, the IC often breaks during bending and assembly operations.

[0036] In order to solve this technical problem, the utility model provides a COF structure for a narrow-frame display screen, comprising a PI layer 1, a copper layer 2 is provided on the upper surface of the PI layer 1, a solder resist layer 3 is provided on the upper surface of the copper layer 2, a chip mounting opening 31 is provided on the solder resist layer 3, and a flexible IC 4 is provided in the chip mounting opening 31. A PI protective layer 5 is provided on the surface of the IC 4. The edge of the PI protective layer 5 covers the solder resist layer 3.

[0037] Through the above structural design, since the edge of the PI protective layer 5 covers the solder resist layer 3, the bonding force between the PI protective layer 5 and the solder resist layer 3 can be effectively improved. At the same time, the edge of the IC 4 can also be protected to prevent it from being damaged by impact.

[0038] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0040] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0041] Example 1

[0042] like Figure 3 As shown, the COF structure for a narrow-frame display screen includes a PI layer 1, a copper layer 2 is provided on the upper surface of the PI layer 1, a solder resist layer 3 is provided on the upper surface of the copper layer 2, a chip mounting opening 31 is provided on the solder resist layer 3, and a flexible IC 4 is provided in the chip mounting opening 31.

[0043] It should be noted that the height of the IC4 is greater than the solder resist layer 3. The copper layer 2 is used to form an electrical connection with the IC4.

[0044] The working mode of this embodiment is described below.

[0045] When assembling, since the PI layer 1, the copper layer 2 and the solder mask layer 3 all have a certain toughness, the bending resistance of the COF structure can be effectively improved. At the same time, they can also form an effective wrapping protection for the flexible IC4 to prevent the COF structure from breaking.

[0046] Example 2

[0047] like Figure 4 As shown, the COF structure for the narrow-frame display screen provided in Example 1 is further optimized. Specifically, a PI protective layer 5 is provided on the surface of the IC 4 .

[0048] It should be noted that the edge of the PI protection layer 5 covers the solder resist layer 3 .

[0049] In addition, the thickness of the PI protection layer 5 is greater than that of the solder resist layer 3 .

[0050] The working mode of this embodiment is described below.

[0051] Since the edge of the PI protective layer 5 covers the solder resist layer 3, the bonding force between the PI protective layer 5 and the solder resist layer 3 can be effectively improved. At the same time, the edge of the IC 4 can also be protected to prevent it from being damaged by impact.

[0052] Example 3

[0053] like Figure 5As shown, the COF structure for the narrow-frame display screen provided in Embodiment 1 or 2 is further optimized. Specifically, an insulating isolation cavity 41 is provided around the IC4. The top of the insulating isolation cavity 41 is wedge-shaped.

[0054] The working mode of this embodiment is described below.

[0055] By utilizing the insulating isolation cavity 41 , the insulating performance of the IC 4 can be effectively improved, the leakage current between the IC 4 and the solder resist layer 3 can be reduced, and the energy consumption can be reduced.

[0056] Example 4

[0057] like Figure 6 As shown, the COF structure for the narrow-frame display screen provided in Embodiment 1 or 2 is further optimized. Specifically, the insulating isolation cavity 41 is filled with insulating resin 6 .

[0058] It should be noted that the insulating resin 6 is a high temperature resistant insulating resin.

[0059] In addition, the insulating resin 6 is a transparent resin.

[0060] The working mode of this embodiment is described below.

[0061] The insulating resin 6 can further improve the insulating performance of IC4, reduce the leakage current between IC4 and solder resist layer 3, and reduce energy consumption. Since the insulating resin 6 is a transparent resin, it is convenient to perform visual inspection or machine inspection on the COF structure.

[0062] In addition, PI herein is polyimide, SR is silicone resin, and IC is integrated circuit.

[0063] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A COF structure for a narrow-frame display screen, characterized in that: The COF structure for a narrow-frame display screen comprises a PI layer (1), a copper-clad layer (2) is provided on the upper surface of the PI layer (1), a solder resist layer (3) is provided on the upper surface of the copper-clad layer (2), a chip mounting opening (31) is provided on the solder resist layer (3), and a flexible IC (4) is provided in the chip mounting opening (31).

2. The COF structure for a narrow-frame display screen according to claim 1, characterized in that: A PI protective layer (5) is provided on the surface of the IC (4).

3. The COF structure for a narrow-frame display screen according to claim 2, characterized in that: The edge of the PI protective layer (5) covers the solder resist layer (3).

4. The COF structure for a narrow-frame display screen according to claim 2, characterized in that: The thickness of the PI protective layer (5) is greater than that of the solder resist layer (3).

5. The COF structure for a narrow-frame display screen according to claim 2, characterized in that: The height of the IC (4) is greater than that of the solder resist layer (3).

6. The COF structure for a narrow-frame display screen according to claim 2, characterized in that: An insulating isolation cavity (41) is provided on the periphery of the IC (4).

7. The COF structure for a narrow-frame display screen according to claim 6, characterized in that: The top of the insulating isolation cavity (41) is wedge-shaped.

8. The COF structure for a narrow-frame display screen according to claim 6, characterized in that: The insulating isolation cavity (41) is filled with insulating resin (6).

9. The COF structure for a narrow-frame display screen according to claim 8, characterized in that: The insulating resin (6) is a high temperature resistant insulating resin.

10. The COF structure for a narrow-frame display screen according to claim 9, characterized in that: The insulating resin (6) is a transparent resin.

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