Flexible circuit board, display module, and display apparatus

Abstract

The present invention relates to a flexible circuit board. The flexible circuit board comprises a flexible circuit board body, an enveloping portion, and an insulating protective layer, wherein a first accommodating cavity is formed between the enveloping portion, the insulating protective layer, and the flexible circuit board body. When a corrosive medium penetrates into an edge of the flexible circuit board, the corrosive medium flows into the first accommodating cavity along a gap between the insulating protective layer and the flexible circuit board body, and a surface of the enveloping portion away from a component blocks the corrosive medium, thereby preventing the corrosive medium from corroding a pad of the component and a connection layer between the pad and a welding surface of the flexible circuit board body, and preventing the flexible circuit board from exhibiting poor conduction. The present disclosure further provides a display module comprising the flexible circuit board, and a display apparatus comprising the display module.

Description

Flexible circuit boards, display modules and display devices

[0001] Cross-references

[0002] This disclosure claims priority to Chinese Patent Application No. 202510051938.4, filed on January 13, 2025, entitled "Flexible Circuit Board, Display Module and Display Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of display technology, and more specifically, to a flexible circuit board, a display module, and a display device. Background Technology

[0004] With the trend of overall thinning of display devices, the internal space of display devices is being utilized more maximally. The components on the flexible circuit board are the thickest parts of the display module, and thinning this area will affect the corrosion resistance of the flexible circuit board.

[0005] In order to reduce the thickness of the display device, the wrapping part is set to only cover the soldering position between the components and the circuit board. Corrosive media can enter the interface between the wrapping part and the components from the upper surface of the components, corroding the connection layer between the components and the flexible circuit board, causing poor conductivity of the flexible circuit board.

[0006] It should be noted that the information in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to solve the problem of poor conductivity of flexible circuit boards caused by corrosion of the welding position between corrosive media and components and circuit boards, and to provide a flexible circuit board, a display module and a display device.

[0008] According to one aspect of the present invention, a flexible circuit board is provided, the flexible circuit board including a flexible circuit board body, components, a connecting layer, a wrapping portion, and an insulating protective layer, the flexible circuit board body having a soldering surface; components disposed on the soldering surface of the flexible circuit board, the components including component bodies and pads, the pads being disposed around the periphery of the component bodies; the connecting layer connecting the soldering surface of the flexible circuit board and the pads; the wrapping portion being disposed on the side of the connecting layer and the pads away from the component bodies; the insulating protective layer covering the soldering surface, the side of the wrapping portion away from the flexible circuit board body, and the side of the components away from the flexible circuit board body; a first receiving cavity is formed between the wrapping portion, the insulating protective layer, and the flexible circuit board body.

[0009] In one embodiment of the present invention, the side of the wrapping portion away from the component includes a first blocking surface. One end of the first blocking surface is in contact with the soldering surface, and the other end is close to the insulating protective layer. The distance between the first blocking surface and the side of the solder pad away from the component body is a first dimension of the wrapping portion. The first dimension of the wrapping portion gradually increases in the direction away from the flexible circuit board body.

[0010] In one embodiment of the present invention, the first blocking surface is an arc-shaped surface that is recessed toward the component body.

[0011] In one embodiment of the present invention, the side of the wrapping portion away from the flexible circuit board body is a support surface, and the distance between the support surface and the welding surface is a second dimension. When the maximum first dimension of the wrapping portion is greater than the second dimension, the shape of the first blocking surface is an elliptical arc surface.

[0012] In one embodiment of the present invention, the side of the wrapping portion away from the flexible circuit board body is a support surface, the distance between the support surface and the welding surface is a second dimension, and when the maximum first dimension of the wrapping portion is less than or equal to the second dimension, the shape of the first blocking surface is an arc surface.

[0013] In one embodiment of the present invention, the angle between the tangent of the side of the first blocking surface away from the flexible circuit board body and the welding surface of the flexible circuit board is greater than 0 degrees and less than 90 degrees.

[0014] In one embodiment of the present invention, the first blocking surface is an inclined surface, the increase in the first size of the wrapping portion is the same along the direction away from the flexible circuit board body, and the angle between the first blocking surface and the side of the pad away from the component body is less than 90 degrees.

[0015] In one embodiment of the present invention, the cross-sectional area of ​​the first receiving cavity is: S>C2×△L×H / C1;

[0016] Where C1 is the perimeter of the device area on the welding surface, C2 is the length of the edge of the insulating protective layer, ΔL is the absorption volume per unit length of the insulating protective layer, and H is the water absorption time.

[0017] In one embodiment of the present invention, the side of the wrapping portion away from the component further includes a second blocking surface, the second blocking surface being connected to the other end of the first blocking surface, and the angle between the second blocking surface and the side of the pad away from the component body being -5 to 5°.

[0018] In one embodiment of the present invention, the second dimension of the wrapping portion gradually increases along the direction close to the component body.

[0019] In one embodiment of the present invention, the support surface is an arc-shaped surface that protrudes away from the flexible circuit board body.

[0020] In one embodiment of the present invention, the side of the wrapping portion away from the flexible circuit board body is lower than the side of the pad away from the flexible circuit board body.

[0021] According to another aspect of the present invention, a display module is provided, comprising a flexible circuit board provided in one aspect of the present invention.

[0022] In one embodiment of the present invention, the display module further includes a mid-frame and a flexible spacer portion, the welding surface includes a device area, the components are disposed in the device area, the flexible spacer portion is interference-fitted between the mid-frame and the flexible circuit board body, and the flexible spacer portion is located on the periphery of the device area.

[0023] In one embodiment of the present invention, the display module further includes a protective layer and a display layer, wherein the protective layer is disposed on the side of the flexible circuit board body away from the insulating protective layer; and the display layer is disposed on the side of the protective layer away from the flexible circuit board body.

[0024] In one embodiment of the present invention, the thickness of the flexible spacer portion must satisfy: (H-δ)×E×S<F;

[0025] H is the thickness of the flexible spacer before assembly, δ is the gap between the flexible circuit board and the middle frame, E is the elastic modulus of the flexible spacer, S is the contact area between the flexible spacer and the flexible circuit board, and F is the maximum force that the display layer can withstand.

[0026] According to another aspect of the present invention, a display device is provided, comprising the display module provided in any other aspect of the present invention.

[0027] The flexible circuit board of the present invention includes a flexible circuit board body, a wrapping portion, and an insulating protective layer, wherein a first receiving cavity is formed between the wrapping portion, the insulating protective layer, and the flexible circuit board body. When a corrosive medium penetrates the edge of the flexible circuit board, the corrosive medium flows along the space between the insulating protective layer and the flexible circuit board body into the first receiving cavity. The side of the wrapping portion away from the components can block the corrosive medium, preventing it from corroding the component pads and the connection layer between the pads and the soldering surface of the flexible circuit board body, thus preventing poor conductivity of the flexible circuit board.

[0028] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0029] 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.

[0030] Figure 1 is a cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the wrapping part completely wraps the entire component.

[0031] Figure 2 is a partial cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the wrapping part completely wraps the entire component.

[0032] Figure 3 is a cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the wrapping part only covers the side of the pad away from the component body, the pad, and the connection layer between the pad and the soldering surface.

[0033] Figure 4 is a partial cross-sectional schematic diagram of a display module according to an embodiment of the present invention, when the wrapping part only covers the side of the pad away from the component body, the pad, and the connection layer between the pad and the soldering surface.

[0034] Figure 5 is a schematic diagram of the intrusion path of the corrosive medium in the embodiments of the present invention when the wrapping part only covers the side of the pad away from the component body, the pad, and the connection layer between the pad and the soldering surface.

[0035] Figure 6 is a cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the first receiving cavity is formed between the wrapping part, the insulating protective layer and the flexible circuit board body.

[0036] Figure 7 is a partial cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the first receiving cavity is formed between the wrapping part, the insulating protective layer and the flexible circuit board body.

[0037] Figure 8 is a partial three-dimensional structural diagram of the display module involved in the embodiment of the present invention when the first receiving cavity is formed between the wrapping part, the insulating protective layer and the flexible circuit board body.

[0038] Figure 9 is a schematic diagram showing the disassembled state of the insulating protective layer and the rest of the flexible circuit board in the embodiment of the present invention when the first receiving cavity is formed between the wrapping part, the insulating protective layer and the flexible circuit board body.

[0039] Figure 10 is a schematic diagram of the intrusion path of the corrosive medium in an embodiment of the present invention when a first receiving cavity is formed between the wrapping part, the insulating protective layer and the flexible circuit board body.

[0040] Figure 11 is a partial cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the shape of the first blocking surface is an arc surface.

[0041] Figure 12 is a partial cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the shape of the first blocking surface is an elliptical arc surface.

[0042] Figure 13 is a partial cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the shape of the first blocking surface is an inclined surface.

[0043] Figure 14 is a partial cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the support surface of the package is set as an inclined plane.

[0044] Figure 15 is a partial cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the supporting surface of the wrapping part is an arc-shaped surface that protrudes away from the flexible circuit board body.

[0045] Figure 16 is a three-dimensional structural diagram of the mold and flexible circuit board involved in the embodiment of the present invention when the two sub-modules are closed to form the above-mentioned molding opening.

[0046] Figure 17 is a cross-sectional schematic diagram of the mold and flexible circuit board involved in the embodiment of the present invention when the two sub-modules are closed to form the above-mentioned molding opening.

[0047] Figure 18 is a three-dimensional structural diagram of the flexible circuit board in this embodiment of the invention when the two sub-modules are separated and removed from the flexible circuit board.

[0048] Figure 19 is a cross-sectional schematic diagram of the flexible circuit board involved in this embodiment of the invention when the two sub-modules are separated and removed from the flexible circuit board.

[0049] Figure 20 is a cross-sectional schematic diagram of the display module involved in the embodiment of the present invention when the flexible spacer is interference-fitted between the middle frame and the flexible circuit board body, and the flexible spacer surrounds the periphery of the device area.

[0050] Figure 21 is a planar schematic diagram of the display module involved in the embodiment of the present invention when the flexible spacer is interference-fitted between the middle frame and the flexible circuit board body, and the flexible spacer surrounds the periphery of the device area.

[0051] Figure 22 is a cross-sectional schematic diagram of the display module according to an embodiment of the present invention when the flexible spacer is separated from the flexible circuit board and the middle frame from the periphery of the device area.

[0052] Figure 23 is a cross-sectional schematic diagram of the display module in an embodiment of the present invention when the flexible spacer is disposed on the periphery of the insulating protective layer.

[0053] In the diagram: 1-Flexible circuit board, 11-Flexible circuit board body, 111-Soldering surface, 1111-Component area, 1112-Peripheral area, 1113-Fingerprint opening, 12-Component, 121-Component body, 122-Solder pad, 13-Connection layer, 14-Wrapping section, 141-First blocking surface, 142-Second blocking surface, 143-Supporting surface, 15-Insulating protective layer, 151-First transition section, 152-Second... Transition section, 153-attachment protrusion, 154-through hole, 16-first receiving cavity, 17-second receiving cavity, 2-protective layer, 3-display layer, 4-polarizer, 5-optical adhesive layer, 6-cover plate, 7-heat dissipation layer, 8-middle frame, 81-bottom, 82-side, 821-mounting groove, 9-flexible spacer, 10-mold, 101-sub-module, 102-forming port, 1021-arc-shaped protrusion, 1022-adhesion surface. Detailed Implementation

[0054] 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, they are provided so that the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted. Furthermore, the drawings are merely illustrative of the invention and are not necessarily drawn to scale.

[0055] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0056] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0057] As shown in Figures 1 and 2, the flexible circuit board 1 includes components 12 and a flexible circuit board body 11. Components 12 are connected to the soldering surface 111 of the flexible circuit board body 11. To prevent corrosive media from eroding the solder pads 122 of components 12 and the soldering position between components 12 and the flexible circuit board 1, thus causing poor conductivity of the flexible circuit board 1, a wrapping part 14 is used to completely wrap the entire component 12. The side of the wrapping part 14 away from the flexible circuit board body 11 is higher than the side of the component 12 away from the flexible circuit board body 11. An insulating protective layer 15 is covered on the soldering surface 111 of the flexible circuit board body 11 and the side of the wrapping part 14 away from the flexible circuit board 1. However, this increases the thickness of the flexible circuit board 1 by 0.2 to 0.5 mm.

[0058] When the flexible circuit board 1 is applied to a display device, a protective layer 2 is provided on the side of the flexible circuit board 1 away from the insulating protective layer 15, a display layer 3 is provided on the side of the protective layer 2 away from the flexible circuit board 1, and a cover plate 6 is provided on the side of the display layer 3 away from the flexible circuit board 1. With the trend of overall thinning of display devices, the internal space utilization of the display device is becoming more extreme. The component 12 on the flexible circuit board 1 is the thickest part of the display module, and thinning this area directly affects the corrosion resistance of the flexible circuit board 1. To reduce the thickness of the flexible circuit board 1, the package of the component 12 can be changed from a larger size to a smaller size, but reducing the package size will weaken the corrosion resistance of the component 12 itself.

[0059] As shown in Figures 3 and 4, the component 12 includes a component body 121 and a pad 122. The pad 122 is located on the periphery of the component body 121. The wrapping portion 14 only covers the side of the pad 122 away from the component body 121 in a direction parallel to the welding surface 111, the pad 122, and the connection layer 13 between the pad 122 and the welding surface 111 of the flexible circuit board body 11. As shown in Figure 5, the side of the etched adhesive away from the flexible circuit board body 11 is flush with the side of the component 12 away from the flexible circuit board body 11. The wrapping part 14 changes from full wrapping to half wrapping. The corrosive medium will invade from between the insulating protective layer 15 and the flexible circuit board body 11 to between the insulating protective layer 15 and the wrapping part 14. The side of the component 12 away from the flexible circuit board body 11 is exposed, causing the corrosive medium to invade the exposed metal area on the upper surface of the component 12 through the space between the insulating protective layer 15 and the wrapping part 14 and gradually corrode the pad 122. In addition, the corrosive medium will also penetrate into the corrosion bonding layer 13 through the interface between the wrapping part 14 and the pad 122, causing poor conductivity of the flexible circuit board 1.

[0060] Based on this, the present invention provides a flexible circuit board 1. As shown in Figures 6 to 19, the flexible circuit board 1 includes a flexible circuit board body 11, components 12, a connecting layer 13, a wrapping portion 14, and an insulating protective layer 15. The flexible circuit board body 11 has a soldering surface 111. The components 12 are disposed on the soldering surface 111 of the flexible circuit board 1, and the components 12 include a component body 121 and a pad 122, with the pad 122 disposed around the component body 121. The connecting layer 13 connects the soldering surface 111 of the flexible circuit board 1 and the pad 122. The wrapping portion 14 is disposed on the side of the connecting layer 13 and the pad 122 away from the component body 121. The insulating protective layer 15 covers the soldering surface 111 of the flexible circuit board body 11, the side of the wrapping portion 14 away from the flexible circuit board body 11, and the side of the components 12 away from the flexible circuit board body 11. A first receiving cavity 16 is formed between the wrapping portion 14, the insulating protective layer 15, and the flexible circuit board body 11.

[0061] The flexible circuit board 1 includes a flexible circuit board body 11, a wrapping portion 14, and an insulating protective layer 15. A first receiving cavity 16 is formed between the wrapping portion 14, the insulating protective layer 15, and the flexible circuit board body 11. When a corrosive medium seeps into the edge of the flexible circuit board 1, the corrosive medium flows along the space between the insulating protective layer 15 and the flexible circuit board body 11 into the first receiving cavity 16. The side of the wrapping portion 14 away from the component 12 can block the corrosive medium, preventing it from corroding the pads 122 of the component 12 and the connection layer 13 between the pads 122 and the soldering surface 111 of the flexible circuit board body 11, thus preventing poor conductivity of the flexible circuit board 1.

[0062] The flexible circuit board 1 involved in the embodiments of the present invention will be described in detail below with reference to specific examples.

[0063] As shown in Figures 6 and 7, the flexible circuit board 1 may include a flexible circuit board body 11 and components 12. The flexible circuit board body 11 has a soldering surface 111, and the soldering surface 111 has a component area 1111. The component 12 is disposed in the component area 1111. A peripheral area 1112 is provided around the component area 1111, and the peripheral area 1112 has a fingerprint opening 1113. The fingerprint opening 1113 is disposed between two adjacent components 12. The component 12 includes a component body 121 and a pad 122. The pad 122 is disposed around the component body 121. A connecting layer 13 is provided between the pad 122 and the component area 1111 of the soldering surface 111. The connecting layer 13 connects the soldering surface 111 of the flexible circuit board 1 and the pad 122. The side of the pad 122 away from the flexible circuit board body 11 may be flush with the side of the component body 121 away from the flexible circuit board body 11.

[0064] The flexible circuit board 1 may further include a wrapping portion 14, which is disposed on the side of the connection layer 13 and the pad 122 away from the component body 121 in a direction parallel to the soldering surface 111. The wrapping portion 14 extends from the side of the connection layer 13 to the side of the pad 122 in a direction perpendicular to the soldering surface 111, with the side of the wrapping portion 14 away from the flexible circuit board body 11 being lower than the sides of the pad 122 and the component body 121 away from the flexible circuit board body 11. It is understood that there is a step difference between the side of the wrapping portion 14 away from the flexible circuit board body 11 and the side of the pad 122 away from the flexible circuit board body 11.

[0065] The flexible circuit board 1 may also include an insulating protective layer 15, which covers the component body 121 and the side of the pad 122 away from the flexible circuit board body 11. The insulating protective layer 15 extends from the side of the pad 122 away from the flexible circuit board body 11 and overlaps with the side of the wrapping portion 14 away from the flexible circuit board body 11. The insulating protective layer 15 extends from the side of the wrapping portion 14 away from the flexible circuit board body 11 and overlaps with the periphery of the component area 1111 of the soldering surface 111 of the flexible circuit board body 11. As shown in Figures 8 and 9, the component 12 is provided with wrapping portions 14 around its periphery. The insulating protective layer 15 forms attachment protrusions 153 in the area where the component 12 is attached to the component 12 and the wrapping portion 14. The insulating protective layer 15 provides a through hole 154 between two attachment protrusions 153. The shape and size of the through hole 154 are the same as the shape and size of the fingerprint opening 1113, and the outline of the through hole 154 overlaps with the outline of the fingerprint opening 1113.

[0066] As shown in Figure 10, since the side of the wrapping portion 14 away from the flexible circuit board body 11 is significantly higher than the soldering surface 111 of the flexible circuit board body 11, the insulating protective layer 15 forms a first transition section 151 between the edge of the wrapping portion 14 away from the flexible circuit board body 11 and the soldering surface 111 of the flexible circuit board 11. A first receiving cavity 16 is formed between the side of the wrapping portion 14 away from the component 12, the first transition section 151 of the insulating protective layer 15, and the soldering surface 111 of the flexible circuit board body 11, parallel to the soldering surface. When corrosive medium seeps into the edge of the flexible circuit board body 11 or the periphery of the fingerprint opening 1113, the corrosive medium enters the first receiving cavity 16 along the path shown in Figure 10, i.e., from between the insulating protective layer 15 and the flexible circuit board 1. The corrosive medium is blocked by the wrapping portion 14 away from the component 12 in the direction parallel to the soldering surface, preventing the corrosive medium from corroding the pads 122 of the component 12 and the connection layer 13 between the pads 122 and the soldering surface 111 of the flexible circuit board body 11, thus preventing poor conductivity of the flexible circuit board 1.

[0067] As shown in Figures 11 to 15, the side of the wrapping portion 14 away from the component 12 along the direction parallel to the soldering surface includes a first blocking surface 141. One end of the first blocking surface 141 is in contact with the soldering surface 111 of the flexible circuit board body 11, and the other end is close to the insulating protective layer 15. The first blocking surface 141 is an arc-shaped surface that is concave towards the component body 121. The distance between the first blocking surface 141 and the side of the solder pad 122 away from the component body 121 is the first dimension L1 of the wrapping portion 14, and the first dimension L1 of the wrapping portion 14 gradually increases along the direction away from the flexible circuit board body 11. The wrapping portion 14 also includes a second blocking surface 142 on the side away from the component 12 along the direction perpendicular to the welding surface. The second blocking surface 142 is connected between the first blocking surface 141 and the side of the wrapping portion 14 away from the flexible circuit board body 11. The second blocking surface 142 is approximately parallel to the side of the pad 122 away from the component body 121. The included angle between the second blocking surface 142 and the side of the pad 122 away from the component body 121 is -5 to -5°.

[0068] The side of the wrapping portion 14 away from the flexible circuit board body 11 is the support surface 143. The distance between the support surface 143 and the welding surface 111 of the flexible circuit board body 11 is the second dimension L2. To prevent moisture from entering and to avoid the wrapping portion 14 from taking up too much space, the second dimension L2 of the wrapping portion 14 is smaller than the height H1 of the component 12 (the height H1 of the component 12 is usually between 0.5 and 0.9 mm). The maximum first dimension L1 of the wrapping portion 14 is < 0.6 mm, that is, the width of the support surface 143 is < 0.6 mm. The maximum first dimension L1 and the second dimension L2 of the wrapping portion 14 can be adjusted within the above range according to the dispensing process capability.

[0069] The cross-sectional area of ​​the first receiving cavity 16 is: S > C2 × ΔL × H / C1; where C1 is the perimeter of the device area 1111 of the welding surface 111, C2 is the length of the edge of the insulating protective layer 15, ΔL is the absorption volume per unit length of the insulating protective layer 15, and H is the water absorption time. The size of the first receiving cavity 16 is always sufficient to accommodate the intruding corrosive medium, ensuring the corrosion resistance of the encapsulated part 14. It should be noted that the corrosive medium mentioned above can be water or a water vapor mixture.

[0070] To enhance the blocking effect of the first blocking surface 141 on the corrosive medium, the increase in the first dimension L1 of the wrapping portion 14 can be set to gradually increase in the direction away from the flexible circuit board body 11. The first blocking surface 141 can be set as an arc-shaped surface, extending its area and gradually increasing its inclination in the direction away from the flexible circuit board body 11. When the maximum first dimension L1 of the wrapping portion 14 is less than or equal to the second dimension L2, the shape of the first blocking surface 141 is an arc surface as shown in Figure 11, and the length of the arc surface can be 1 / 4 of a circle. When there is sufficient horizontal space and the maximum first dimension L1 of the wrapping portion 14 is greater than the second dimension L2, the shape of the first blocking surface 141 can be an elliptical arc surface as shown in Figure 12, increasing the space for accommodating the corrosive medium.

[0071] In one possible implementation, the angle between the tangent T1 of the first blocking surface 141 on the side away from the flexible circuit board body 11 and the welding surface 111 of the flexible circuit board 1 is greater than 0 degrees and less than 90 degrees, which can effectively prevent moisture from intruding along the first blocking surface 141 to the second blocking surface 142 and the support surface 143. In this embodiment, the tangent of the end of the first blocking surface 141 away from the flexible circuit board body 11 can be set to be parallel to the welding surface 111 of the flexible circuit board 1.

[0072] As shown in Figure 13, when the shape of the first blocking surface 141 is affected by the manufacturing capability, the first blocking surface 141 can be selected as an inclined surface with lower processing difficulty. The increase in the first dimension L1 of the wrapping part 14 is the same in the direction away from the flexible circuit board body 11. The included angle between the first blocking surface 141 and the side of the pad 122 away from the component body 121 is less than 90 degrees.

[0073] As shown in Figures 11 to 13, when the support surface 143 is parallel to the soldering surface 111 of the flexible circuit board body 11, when the insulating protective layer 15 transitions from the side of the pad 122 away from the flexible circuit board body 11 to the support surface 143 of the wrapping portion 14, since there is a step difference between the side of the insulating protective layer 15 away from the pad 122 and the support surface 143 of the wrapping portion 14, the insulating protective layer 15 will form a second transition section 152 between the edge of the side of the pad 122 away from the flexible circuit board body 11 and the side of the wrapping portion 14 away from the flexible circuit board body 11. The second transition section 152, the support surface 143 of the wrapping portion 14 and the side of the pad 122 can easily form a second receiving cavity 17. When corrosive media invades between the support surface 143 of the wrapping portion 14 and the insulating protective layer 15, it is easy to stay in the second receiving cavity 17, increasing the risk of the pad 122 being corroded.

[0074] Therefore, the second dimension L2 of the wrapping portion 14 is gradually increased along the direction close to the component body 121, that is, the support surface 143 of the wrapping portion 14 is an inclined surface. This allows the insulating protective layer 15 to closely adhere to the support surface 143 of the wrapping portion 14 when transitioning from the side of the pad 122 away from the flexible circuit board body 11 to the support surface 143 of the wrapping portion 14, preventing the retention of corrosive media and thus reducing the risk of corrosion of the pad 122. As shown in Figure 14, the support surface 143 of the wrapping portion 14 can be set as an inclined plane. As shown in Figure 15, the support surface 143 can also be an arc-shaped surface convex in the direction away from the flexible circuit board body 11. The width of the arc-shaped surface is larger than the width of the inclined plane, which can increase the climbing distance of the corrosive media and further enhance the corrosion resistance of the flexible circuit board 1.

[0075] Taking the structure of the wrapping part 14 in Figure 11 as an example, the formation process of the first receiving cavity 16 will be explained:

[0076] As shown in Figures 16 to 19, when the pad 122 is soldered to the device area 1111 of the soldering surface 111 of the flexible circuit board body 11 through the connecting layer 13, a mold 10 is provided on the soldering surface 111 of the flexible circuit board 1 as shown in the figure. The mold 10 has a forming opening 102, the size of which is adapted to the size of the component 12, and the side of the forming opening 102 is close to the side of the pad 122 of the component 12. To facilitate demolding, the mold 10 is divided into two sub-modules 101, which together form the forming opening. The side of the forming opening 102 has an arc-shaped protrusion 1021 and a mating surface 1022. The mating surface 1022 is recessed towards the center of the mold 10 relative to the arc-shaped protrusion 1021. The arc-shaped protrusion 1021 matches the first blocking surface 141, and the mating surface 1022 matches the second blocking surface 142.

[0077] When the two sub-modules 101 are closed, i.e., when the mating surfaces 1022 of the two sub-modules 101 come into contact with each other, the side of the molding opening 102, the side of the component 12 pad 122, and the soldering surface 111 of the flexible circuit board 1 form a filling space. The wrapping part 14 can be made of anti-corrosion adhesive. The anti-corrosion adhesive is poured into the filling space, and the amount of adhesive is controlled to ensure that the anti-corrosion adhesive does not overflow the mold 10. The height of the anti-corrosion adhesive is less than or equal to the height of the pad 122 and the height of the component body 121. After the adhesive is applied, the anti-corrosion adhesive is cured and shaped. Then the two sub-modules 101 are separated, the mold 10 is removed, and the wrapping part 14 is formed on the side away from the component 12.

[0078] Finally, the insulating protective layer 15 is attached to the welding surface 111 of the flexible circuit board body 11, the side of the wrapping portion 14 away from the flexible circuit board body 11, and the side of the component 12 away from the flexible circuit board body 11, thus obtaining the first receiving cavity 16 that blocks corrosive media.

[0079] The present invention also provides a display module. As shown in Figures 20 to 22, the display module may include a flexible circuit board 1, a middle frame 8, and a flexible spacer 9. The welding surface 111 of the flexible circuit board body 11 includes a device area 1111, and the components 12 are disposed in the device area 1111. The flexible spacer 9 is interference-fitted between the middle frame 8 and the flexible circuit board body 11, and the flexible spacer 9 surrounds the periphery of the device area 1111.

[0080] Each component 12 is surrounded by a flexible spacer 9. The flexible spacer 9 can seal the components 12 within the component area 1111, ensuring the corrosion resistance of the flexible circuit board 1 and thus ensuring the reliability of the display module. In this embodiment, a conventional flexible circuit board 1 is used, which avoids the problem of unevenness of the flexible circuit board 1 caused by the volume change of the wrapping part 14 during curing after the wrapping part 14 is set around the component area 1111, which would otherwise cause the insulating protective layer 15 to lift up.

[0081] A heat dissipation layer 7 is provided on the side of the flexible circuit board body 11 away from the insulating protective layer 15. A protective layer 2 is provided on the side of the heat dissipation layer 7 away from the flexible circuit board 1. A display layer 3 is provided on the side of the protective layer 2 away from the flexible circuit board 1. A polarizer 4 can also be provided on the side of the display layer 3 away from the flexible circuit board 1 to reduce the reflection of the display layer 3. A cover plate 6 can also be provided on the side of the polarizer 4 away from the flexible circuit board 1. An optical adhesive layer 5 is provided between the cover plate 6 and the polarizer 4 to bond the cover plate 6 to the polarizer 4.

[0082] It should be further explained that the middle frame 8 includes a bottom 81 and a side 82. The side 82 is connected to the edge of the bottom 81 and is perpendicular to the bottom 81. The side 82 is provided with a mounting groove 821. The cover plate 6 overlaps in the mounting groove 821 and contacts the side wall and bottom wall of the mounting groove 821. The flexible spacer 9 is interference-fitted with the welding surface 111 of the flexible circuit board body 11 and the bottom 81 of the middle frame 8.

[0083] As shown in Figure 22, the thickness of the flexible spacer 9 must satisfy: (H-δ)×E×S<F; where H is the thickness of the flexible spacer 9 before assembly, δ is the gap between the flexible circuit board 1 and the middle frame 8, E is the elastic modulus of the flexible spacer 9, S is the contact area between the flexible spacer 9 and the flexible circuit board 1, and F is the maximum force that the display layer 3 can withstand. The thickness H of the flexible spacer 9 before assembly is greater than the gap δ between the flexible circuit board 1 and the middle frame 8. By limiting it with the above formula, it is ensured that the flexible spacer 9, while having an interference fit with the middle frame 8 and the flexible circuit board body 11, avoids damaging the display layer 3 and affecting the display effect.

[0084] This invention also provides a display module. As shown in FIG23, the display module may include the flexible circuit board 1 mentioned in any of the embodiments of this invention above. The specific structure and beneficial effects of the flexible circuit board 1 have been described in detail above, and therefore will not be repeated here. It is understood that improving the corrosion resistance of the flexible circuit board 1 can improve the reliability of the display module.

[0085] The display module may also include a mid-frame 8 and a flexible spacer 9. The welding surface 111 of the flexible circuit board body 11 includes a device area 1111. Components 12 are disposed in the device area 1111. The flexible spacer 9 is interference-fitted between the mid-frame 8 and the flexible circuit board body 11. The flexible spacer 9 surrounds the periphery of the device area 1111. Here, the flexible spacer 9 is disposed on the periphery of the insulating protective layer 15.

[0086] The flexible spacer 9 seals the edge of the insulating protective layer 15, preventing corrosive media from entering the device area 1111 between the insulating protective layer 15 and the flexible circuit board body 11, thus corroding the components 12 and achieving corrosion protection for the flexible circuit board 1. Even if corrosive media enters the area enclosed by the flexible spacer 9, the side of the wrapping portion 14 away from the components 12 can also block the corrosive media, preventing it from corroding the pads 122 of the components 12 and the connection layer 13 between the pads and the solder surface 111 of the flexible circuit board body 11, thus preventing poor conductivity of the flexible circuit board 1. In summary, this display module has good corrosion resistance.

[0087] This invention also provides a display device. This display device may include the display module described in any of the above embodiments of this invention. The specific structure and beneficial effects of the display module have been described in detail above, and therefore will not be repeated here.

[0088] It should be noted that, in addition to the display module, the display device also includes other necessary components and parts, such as the housing, control circuit board, power cord, etc. Those skilled in the art can make corresponding additions according to the specific usage requirements of the display device, which will not be elaborated here.

[0089] When the display module has the structure shown in the figure, the display device can be a traditional electronic device, such as a mobile phone, computer, television and video recorder, or an emerging wearable device, such as virtual reality device and augmented reality device, which will not be listed here.

[0090] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the appended claims.

Claims

1. A flexible circuit board, wherein, include: The flexible circuit board body has a soldering surface; A component is disposed on a soldering surface. The component includes a component body and a solder pad, and the solder pad is disposed on the periphery of the component body. A connecting layer that connects the welding surface to the solder pad; The wrapping portion is located on the side of the connecting layer and the solder pad away from the component body; An insulating protective layer covers the welding surface, the side of the wrapping portion away from the flexible circuit board body, and the side of the component away from the flexible circuit board body; A first receiving cavity is formed between the wrapping part, the insulating protective layer and the flexible circuit board body.

2. The flexible circuit board according to claim 1, wherein, The side of the wrapping portion away from the component includes a first blocking surface. One end of the first blocking surface is in contact with the soldering surface, and the other end is close to the insulating protective layer. The distance between the first blocking surface and the side of the solder pad away from the component body is the first dimension of the wrapping portion. The first dimension of the wrapping portion gradually increases in the direction away from the flexible circuit board body.

3. The flexible circuit board according to claim 2, wherein, The first blocking surface is an arc-shaped surface that is concave towards the body of the component.

4. The flexible circuit board according to claim 3, wherein, The side of the wrapping portion away from the flexible circuit board body is the support surface. The distance between the support surface and the welding surface is the second dimension. When the maximum first dimension of the wrapping portion is greater than the second dimension, the shape of the first blocking surface is an elliptical arc surface.

5. The flexible circuit board according to claim 3, wherein, The side of the wrapping portion away from the flexible circuit board body is the support surface, and the distance between the support surface and the welding surface is the second dimension. When the maximum first dimension of the wrapping portion is less than or equal to the second dimension, the shape of the first blocking surface is an arc surface.

6. The flexible circuit board according to claim 3, wherein, The angle between the tangent on the side of the first blocking surface away from the flexible circuit board body and the welding surface of the flexible circuit board is greater than 0 degrees and less than 90 degrees.

7. The flexible circuit board according to claim 2, wherein, The first blocking surface is an inclined surface, the increase in the first dimension of the wrapping portion is the same in the direction away from the flexible circuit board body, and the angle between the first blocking surface and the side of the pad away from the component body is less than 90 degrees.

8. The flexible circuit board according to claim 1, wherein, The cross-sectional area of ​​the first receiving cavity is: S>C2×△L×H / C1; Wherein, C1 is the perimeter of the device area of ​​the welding surface, C2 is the length of the edge of the insulating protective layer, ΔL is the absorption volume per unit length of the insulating protective layer, and H is the water absorption time.

9. The flexible circuit board according to claim 2, wherein, The side of the packaged portion away from the component also includes a second blocking surface, which is connected to the other end of the first blocking surface. The angle between the second blocking surface and the side of the pad away from the component body is -5 to 5°.

10. The flexible circuit board according to claim 4 or 5, wherein, The second dimension of the package gradually increases along the direction closer to the component body.

11. The flexible circuit board according to claim 10, wherein, The supporting surface is an arc-shaped surface that protrudes away from the flexible circuit board body.

12. The flexible circuit board according to claim 1, wherein, The side of the wrapping portion away from the flexible circuit board body is lower than the side of the solder pad away from the flexible circuit board body.

13. A display module, wherein, Includes the flexible circuit board as described in any one of claims 1 to 12.

14. The display module according to claim 13, wherein, The display module further includes a mid-frame and a flexible spacer. The welding surface includes a device area, and the components are disposed in the device area. The flexible spacer is interference-fitted between the mid-frame and the flexible circuit board body, and the flexible spacer is located on the periphery of the device area.

15. The display module according to claim 14, wherein, The display module also includes: A protective layer is disposed on the side of the flexible circuit board body away from the insulating protective layer; The display layer is located on the side of the protective layer away from the flexible circuit board body.

16. The display module according to claim 15, wherein, The thickness of the flexible septum portion must satisfy: (H-δ)×E×S<F; H is the thickness of the flexible spacer before assembly, δ is the gap between the flexible circuit board and the middle frame, E is the elastic modulus of the flexible spacer, S is the contact area between the flexible spacer and the flexible circuit board, and F is the maximum force that the display layer can withstand.

17. A display device, wherein, Includes the display module as described in claim 16.

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