COF flexible display

Abstract

The present invention discloses a COF flexible display screen, comprising a flexible circuit board, a flexible mounting layer, a mesh frame, a protective layer and a plurality of display chips. The mesh frame and the display chip are both arranged on the front of the flexible circuit board, the mesh frame has a positioning area for positioning the display chip before the display chip is packaged on the flexible circuit board, the display chip is packaged in the positioning area through COF, the protective layer covers the front of the flexible circuit board, the display chip and the mesh frame, and the flexible display screen is installed in a bent manner with the help of the flexible mounting layer. The display chip of the present invention is packaged on the front of the flexible circuit board through COF, thereby reducing the difficulty of packaging the display chip and the flexible circuit board and making the connection structure between the two more stable, and also having good heat dissipation effect, reducing production cost, good display effect, preventing the display chip from being damaged or falling off the flexible circuit board when receiving external pressure, and facilitating the positioning of the display chip.

Description

Technical Field

[0001] The present invention relates to the field of display screens, and in particular to a COF flexible display screen. Background Art

[0002] With the rapid development of society, the manufacturing process is becoming more and more mature. Display screens, as a display tool that displays certain electronic files on the screen through specific transmission equipment and then reflects them to the human eye, can display various information that people want on the screen through preset programs. Therefore, they are widely used in advertising signs, televisions, mobile phones, etc.

[0003] In order to cater to the need of displaying on objects with a certain degree of curvature on the surface, a bendable and foldable flexible display screen is becoming more and more popular in the market. The existing flexible display screen mainly includes a flexible circuit board, a display chip and a flexible mounting layer; wherein the flexible circuit board is arranged on the front of the flexible mounting layer, and the display chip is installed on the front of the flexible circuit board. Therefore, in actual use, a magnet can be installed at the flexible mounting layer to magnetically attract the flexible display screen to the surface of some metal objects, or glue can be applied between the flexible mounting layer and the object to be displayed to achieve the fixation of the two. However, the installation of the display chip in the existing flexible display screen is achieved by SMD (Surface Mounted Devices) technology, which generally includes the following steps: printing flux on the PCB, using standard pick-and-place tools for component placement, and reflow soldering and cleaning of solder bumps (depending on the type of flux). The advantages of soldering display chips on flexible circuit boards using SMD technology are as follows: high assembly density, small size and light weight of electronic products, high reliability, strong vibration resistance, and reduced electromagnetic and radio frequency interference. However, there are also the following defects: (1) The packaging efficiency is not high enough, and the damage rate during installation and use is also very high; (2) Since heat conduction is carried out through the path of chip-soldering glue-solder point-solder paste-steel foil-insulating layer-aluminum material, the thermal resistance of the flexible display screen soldered using SMD technology is also relatively high, and the display screen using SMD technology may also be damaged when it is cleaned; (3) The combination of discrete devices has point light, glare, etc., and due to the technical problems of SMD itself (that is, the spacing between display chips has a minimum limit value), it is difficult to increase the fineness of the display screen; (4) The cost of brackets and solder paste is increased, and the cost of patch and reflow soldering processes needs to be increased.

[0004] Therefore, there is an urgent need for a COF flexible display screen that can reduce packaging difficulty, has good heat conduction effect, facilitates accurate positioning of display chips, reduces production costs, has a stable connection structure and good display effect. Summary of the invention

[0005] The object of the present invention is to provide a COF flexible display screen which can reduce packaging difficulty, has good heat conduction effect, facilitates accurate positioning of display chips, reduces production costs, has a stable connection structure and good display effect.

[0006] In order to achieve the above-mentioned object, the present invention provides a COF flexible display screen, comprising a flexible circuit board and a flexible mounting layer arranged on the back side of the flexible circuit board, the COF flexible display screen also comprises a mesh skeleton, a protective layer and a plurality of display chips, the mesh skeleton and the display chip are both arranged on the front side of the flexible circuit board, the mesh skeleton has a positioning area for positioning the display chip before the display chip is packaged in the flexible circuit board, the display chip is packaged in the positioning area through COF, the protective layer covers the front side of the flexible circuit board, the display chip and the mesh skeleton, and the COF flexible display screen is installed in a bent manner with the help of the flexible mounting layer.

[0007] Preferably, the upper surface of the mesh skeleton is serrated.

[0008] Preferably, a plurality of refraction units are disposed on the protection layer, the refraction units correspond to the display chips one by one, and the refraction units are disposed directly above the display chips, and the refraction units are arched in a direction away from the display chip.

[0009] Preferably, the protective layer is an epoxy resin layer.

[0010] Preferably, the display chip is an LED display chip.

[0011] Preferably, the flexible mounting layer is provided with a plurality of first grooves and a plurality of second grooves, and the first grooves and the second grooves are arranged alternately.

[0012] Preferably, the COF flexible display screen further includes a plurality of electronic components, and the electronic components are arranged on the back side of the flexible circuit board.

[0013] Preferably, the flexible mounting layer is provided with a receiving cavity for receiving the electronic components.

[0014] Preferably, an elastic sheet layer is further provided between the flexible mounting layer and the flexible circuit board.

[0015] Preferably, the flexible mounting layer is a transparent sheet.

[0016] Compared with the prior art, since the display chip of the present invention is packaged on the front side of the flexible circuit board through COF, the difficulty of packaging the display chip and the flexible circuit board can be reduced and the connection structure between the two is more stable, so that the COF flexible display screen of the present invention has good heat dissipation effect, reduces production costs and makes the display effect better; at the same time, the present invention also provides a protective layer covering the front side of the flexible circuit board and the display chip on the flexible circuit board, so it can effectively prevent the display chip from being damaged or falling off the flexible circuit board when receiving external pressure, and can also prevent dust from adhering to the flexible circuit board and causing poor contact; finally, the present invention also provides a mesh skeleton on the flexible circuit board, and the mesh skeleton has a positioning area for positioning the display chip before the display chip is packaged on the flexible circuit board, so that the display chip can be positioned more accurately during installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the COF flexible display screen of the present invention after the refractive unit is hidden.

[0018] Figure 2 It is a structural schematic diagram of the back side of the COF flexible display screen of the present invention.

[0019] Figure 3 It is a side view of the COF flexible display screen of the present invention.

[0020] Figure 4 yes Figure 3 An enlarged view of the local structure of the COF flexible display shown. DETAILED DESCRIPTION

[0021] In order to explain the technical content, structural features and achieved effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0022] Please refer to Figure 1 and Figure 2The present invention provides a COF flexible display screen 100, comprising a flexible circuit board 10, a flexible mounting layer 20 disposed on the back of the flexible circuit board 10, a protective layer 30 disposed on the flexible circuit board 10, and a plurality of display chips 40. The display chip 40 is packaged on the front of the flexible circuit board 10 through COF, the protective layer 30 is disposed on the front of the flexible circuit board 10, the protective layer 30 covers the front of the flexible circuit board 10 and all the display chips 40, and the flexible display screen is installed in a curved manner with the help of the flexible mounting layer 20. Specifically, the protective layer 30 is an epoxy resin layer, so that the protective layer 30 covers the entire front of the flexible circuit board 10, which can prevent external dust or liquid from entering the flexible circuit board 10 and causing the COF flexible display screen 100 of the present invention to short-circuit, and the protective layer 30 covers the display chip 40, which effectively prevents the display chip 40 from being damaged under the pressure of external force. Preferably, the protective layer 30 can be set by a technician in this field to be transparent or with different colors, so as to cooperate with the chip to show different display states, but it is not limited to this. For example, the display chip 40 may be an LED display chip 40 , but is not limited thereto.

[0023] Please refer to Figures 1 to 4, the COF flexible display screen 100 also includes a mesh skeleton 50, an elastic layer 60 and a plurality of electronic components 70. The electronic components 70 are arranged on the back of the flexible circuit board 10, so when the COF flexible display screen 100 of the present invention is installed in the external environment, the electronic components 70 located on the back of the flexible circuit board 10 are less susceptible to external interference and are convenient to connect with the circuit. The elastic layer 60 is installed between the flexible mounting layer 20 and the flexible circuit board 10. Preferably, the elastic layer 60 is made of transparent plastic, so the elastic layer 60 can be used to increase the toughness of the COF flexible display screen 100 of the present invention, so that the COF flexible display screen 100 of the present invention can be better fixed into a certain curved shape and then installed, but it is not limited to this. The mesh skeleton 50 is fixed to the front of the flexible circuit board 10, and the mesh skeleton 50 has a positioning area 50a for positioning the display chip 40 before the display chip 40 is encapsulated in the flexible circuit board 10, and the display chip 40 is encapsulated in the positioning area 50a through COF. Preferably, the mesh frame 50 is a silicone panel and a plurality of display chips 40 are installed in the mesh frame 50 in a matrix distribution, so that the display chips 40 can be better fixed in the mesh frame 50 to prevent damage caused by impact from foreign objects, but it is not limited thereto. Specifically, the upper surface of the mesh skeleton 50 is serrated, that is, when the display chip 40 is fixed in the positioning area 50a, the protective layer 30 is simultaneously coated on the front of the flexible mounting layer 20, the display chip 40 and the mesh skeleton 50, so the protective layers 30 at each positioning area 50a are interconnected, making the structure of the protective layer 30 of the present invention more stable, and when the front of the COF flexible display screen 100 of the present invention is squeezed, since the upper surface of the mesh skeleton 50 is serrated, not only the contact area between the mesh skeleton 50 and the protective layer 30 is increased, so that the protective layer 30 can be more stably fixed on the mesh skeleton 50, but also the mesh skeleton 50 also has a certain function of bearing external force, further protecting the display chip 40 located in the positioning area 50a from damage. Preferably, the flexible mounting layer 20 can be a flexible silicone layer, but is not limited thereto. It is worth noting that the COF flexible display screen 100 of the present invention is arranged with a protective layer 30, a mesh skeleton 50, a flexible circuit board 10, an elastic sheet 60 and a flexible mounting layer 20 in sequence from the front to the back, wherein the mesh skeleton 50 and the flexible circuit board 10, the flexible circuit board 10 and the elastic sheet 60, and the elastic sheet 60 and the flexible mounting layer 20 can be tightly connected by a pasting method commonly used by technicians in this field, such as glue, adhesive paper or tape, etc.

[0024] Please refer to Figure 3 and Figure 4, a plurality of refraction units 31 are disposed on the protective layer 30, and the refraction units 31 correspond to the display chips 40 one by one, and the refraction units 31 are disposed directly above the display chips 40, and the refraction units 31 are arched in the direction away from the display chips 40, so the display chips 40 can be refracted at different angles by different degrees of arching of the refraction units 31. It is worth noting that the one-to-one correspondence between the refraction units 31 and the display chips 40 in this specification means that the number of the refraction units 31 is equal to the number of the display chips 40, and each display chip 40 has and only has one refraction unit 31 disposed directly above it.

[0025] Please continue to refer to Figures 1 to 4 The flexible mounting layer 20 is provided with a receiving cavity 20a for receiving the electronic components 70, and a plurality of first grooves 21 and a plurality of second grooves 22. The first grooves 21 and the second grooves 22 are arranged in an interlaced manner, so that when the COF flexible display screen 100 of the present invention is bent and folded, it can be bent along the length direction of the first groove 21 or the second groove 22; specifically, the first groove 21 and the second groove 22 are arranged perpendicular to each other; that is, the first groove 21 and the second groove 22 arranged side by side separate the flexible mounting layer 20 into a plurality of small pieces, so that the flexible display screen of the present invention is installed in a bent manner, and the first groove 21 and the second groove 22 are also conducive to the heat dissipation of the flexible circuit board 10, but not limited thereto. In other embodiments, in addition to being arranged perpendicular to each other, the first groove 21 and the second groove 22 can also be arranged in an interlaced manner at other angles, but not limited thereto.

[0026] It is worth noting that the flexible mounting layer 20 of the COF flexible display screen 100 of the present invention can be set as a transparent plastic sheet, the flexible circuit board 10 can be a printed circuit attached to the front of the flexible mounting layer 20, and the display chip 40 is arranged on the front of the flexible circuit board 10; since the flexible mounting layer 20 of the present invention is a complete transparent sheet, the flexible display screen of the present invention has a better bending degree, is lighter in weight, and is easier to carry and install, but is not limited to this. For example, the external environment in which the COF flexible display screen 100 of the present invention can be installed includes: metal that can be adsorbed by strong magnets located outdoors or indoors, and glass or concrete that cannot be adsorbed by strong magnets located outdoors or indoors. When the COF flexible display screen 100 of the present invention needs to be installed on a metal surface that can be adsorbed by a strong magnet, a strong magnet can be provided on the flexible installation layer 20, and then the COF flexible display screen 100 of the present invention can be adsorbed on the metal surface by the strong magnet; when the COF flexible display screen 100 of the present invention needs to be installed on a glass or concrete surface that cannot be adsorbed by a strong magnet, the COF flexible display screen 100 of the present invention can be fixed to the surface by an external adhesive such as glue. At the same time, the COF flexible display screen 100 of the present invention can also be sprayed with nano-level waterproof and UV-releasing coatings on its surface to enhance the waterproof and UV-releasing performance of the COF flexible display screen 100 of the present invention.

[0027] It is worth noting that the COF flexible display screen 100 of the present invention refers to a flexible display screen made using COF packaging (ChipOn Flex) technology, which is a technology that uses a soft additional circuit board as a packaging chip carrier to connect the chip to the flexible substrate circuit. The manufacturing process of the COF flexible display screen 100 of the present invention is based on the original COF packaging technology, and its purpose is to make the COF technology better combined with the flexible display screen. The main improvements include the use of 4.8-5.8mm board integrated packaging, and the surface of the protective layer 30 is diffusely reflected. The main process flow mainly includes: solid crystal, wire bonding, testing, glue filling, packaging, light separation and color separation, cutting, and baking. First, since the COF flexible display screen 100 only provides a display function, the COF flexible display screen 100, the power supply and the control system are installed separately, which can ensure that the heat sources of the COF flexible display screen 100, the power supply and the control system will not accumulate or overlap, and ensure a good heat dissipation effect during actual use; and by avoiding the installation of a power supply on the COF flexible display screen 100, it can be prevented that the heat conduction of the power supply will affect the signal reception of the screen body. Since the service life of the power supply is shorter than the screen body during actual use, it can be avoided that the COF flexible display screen 100 is damaged due to misoperation when the power supply is replaced. Specifically, the two opposite sides of the flexible installation layer 20 of the COF flexible display screen 100 of the present invention can be provided with a concave-convex complementary snap-fit ​​structure, and the adjacent two flexible display screens 100 are docked and inserted and snap-fitted by the concave-convex complementary snap-fit ​​structure to achieve splicing positioning. Preferably, the power drive of the COF flexible display screen 100 of the present invention can adopt the pinpoint heat dissipation principle, so as to achieve the beneficial effects of low temperature, long life, less failure, maintenance-free and energy saving. Conductive components may also be installed on the flexible mounting layer 20 of the COF flexible display screen 100 of the present invention. During installation, the COF flexible display screen 100 may be powered on by mounting the conductive components of the flexible mounting layer 20 on a conductive frame in the external environment. That is to say, the connection between the COF flexible display screen 100 and the power supply is achieved through the connection between the conductive components and the conductive frame. Therefore, in the actual installation process, once the COF flexible display screen 100 is installed on the conductive frame, it may emit light in an orderly manner according to the preset conditions. At the same time, the installation process of the COF flexible display screen 100 may save many electrical cables. Therefore, the installation of the COF flexible display screen 100 is simpler, and the thickness of the COF flexible display screen 100 may be greatly reduced.

[0028] Compared with the prior art, since the display chip 40 of the present invention is packaged on the front side of the flexible circuit board 10 through COF, the difficulty of packaging the display chip 40 and the flexible circuit board 10 can be reduced and the connection structure between the two can be more stable, so that the COF flexible display screen 100 of the present invention has good heat dissipation effect, reduces production costs and has better display effect; at the same time, the present invention also provides a protective layer 30 covering the front side of the flexible circuit board 10 and the display chip 40 on the flexible circuit board 10, so it can effectively prevent the display chip 40 from being damaged or falling off the flexible circuit board 10 when receiving external pressure, and can also prevent dust from adhering to the flexible circuit board 10 and causing poor contact; finally, the present invention also provides a mesh skeleton 50 on the flexible circuit board 10, and the mesh skeleton 50 has a positioning area for positioning the display chip 40 before the display chip 40 is packaged in the flexible circuit board 10, so that the display chip 40 can be positioned more accurately during installation.

[0029] The above disclosure is only a preferred embodiment of the present invention, which is to facilitate the understanding and implementation of the present invention by those skilled in the art. It certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. A COF flexible display screen, comprising a flexible circuit board and a flexible mounting layer arranged on the back of the flexible circuit board, characterized in that: The COF flexible display screen further comprises a mesh frame, a protective layer and a plurality of display chips. The mesh frame and the display chips are both arranged on the front side of the flexible circuit board. The mesh frame has a positioning area for positioning the display chip before the display chip is packaged on the flexible circuit board. The display chip is packaged in the positioning area through COF. The protective layer covers the front side of the flexible circuit board, the display chip and the mesh frame. The COF flexible display screen is installed in a curved manner by means of the flexible mounting layer. Wherein, the upper surface of the mesh skeleton is serrated; The COF flexible display screen also includes a plurality of electronic components, and the electronic components are arranged on the back side of the flexible circuit board.

2. The COF flexible display screen according to claim 1, characterized in that: A plurality of refraction units are arranged on the protection layer. The refraction units correspond to the display chips one by one and are arranged directly above the display chips. The refraction units are arched in a direction away from the display chips.

3. The COF flexible display screen according to claim 1, characterized in that: The protective layer is an epoxy resin layer.

4. The COF flexible display screen according to claim 1, characterized in that: The display chip is an LED display chip.

5. The COF flexible display screen according to claim 1, characterized in that: The flexible installation layer is provided with a plurality of first grooves and a plurality of second grooves, and the first grooves and the second grooves are arranged alternately.

6. The COF flexible display screen according to claim 1, characterized in that: The flexible installation layer is provided with a receiving cavity for receiving the electronic components.

7. The COF flexible display screen according to claim 1, characterized in that: An elastic sheet layer is also arranged between the flexible mounting layer and the flexible circuit board.

8. The COF flexible display screen according to claim 1, characterized in that: The flexible installation layer is a transparent sheet.

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