Flexible circuit board, display module and display apparatus

Abstract

A flexible circuit board. The flexible circuit board comprises a connecting portion (2), wherein the connecting portion (2) comprises a first wiring layer (212), a first insulating layer (23) and an electromagnetic shielding layer (24) which are arranged in a stacked manner, and the part of the first wiring layer (212) between grounding units (2122) is removed, such that the thickness of the connecting portion (2) in the region can be reduced, thereby reducing the bending rebound force of the connecting portion (2). The first insulating layer (23) has an exposure region (232); the electromagnetic shielding layer (24) is connected to the grounding units (2122) via the exposure region (232); at least part of at least one first grounding line is exposed from the first insulating layer (23), and the electromagnetic shielding layer (24) is connected to the exposed part of the first grounding line; and the grounding units (2122) and the first grounding line can ensure the grounding effect of the electromagnetic shielding layer (24). Therefore, the flexible circuit board can ensure the grounding effect of the electromagnetic shielding layer (24) of the connecting portion (2), and can also ensure the bending performance of the connecting part (2). Further provided are a display module comprising the flexible circuit board, and a display apparatus comprising the display module.

Description

Flexible circuit board, display module and display device

[0001] Cross-references

[0002] This disclosure claims priority to Chinese patent application number 202311116787.3 filed on August 31, 2023, entitled “Flexible circuit board, display module and display device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of display technology, and in particular to a flexible circuit board, a display module, and a display device. Background Art

[0004] In order to facilitate the assembly of the display module, the connection portion of the flexible circuit board will be bent back, so the connection portion will be set and a bending area will be reserved at the connection portion.

[0005] More and more functions are integrated into display devices. While ensuring the grounding effect of the electromagnetic shielding layer of the connection part, the bending performance of the connection part must also be taken into consideration.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field.

[0007] Summary of the Invention

[0008] The purpose of the present disclosure is to overcome the above-mentioned deficiencies of the prior art and to provide a flexible circuit board, a display module and a display device.

[0009] According to one aspect of the present disclosure, a flexible circuit board is provided, comprising a connecting portion extending along a first direction, the connecting portion comprising a first circuit board layer group, a first insulating layer and an electromagnetic shielding layer, the first circuit board layer group comprising a first substrate and a first routing layer, the first routing layer being arranged on one side of the first substrate, the first routing layer comprising a plurality of grounding units spaced apart along the first direction, a first routing portion being provided on one side of the plurality of grounding units, the first routing portion comprising a first grounding wire; a first insulating layer being arranged on a side of the first routing layer away from the first substrate, the first insulating layer being provided with an exposed area, the orthographic projection of the exposed area on the first substrate overlapping with the orthographic projection of the grounding unit on the first substrate, the first insulating layer exposing at least a portion of the first grounding wire; an electromagnetic shielding layer being arranged on a side of the first insulating layer away from the first substrate, the electromagnetic shielding layer being connected to the grounding unit through the exposed area, and being connected to the exposed portion of the first grounding wire.

[0010] In one embodiment of the present disclosure, a first routing portion is provided on one side of the multiple grounding units, and a first routing portion or a second routing portion is provided on the other side. The first routing portion is used to bind to the display panel, and the second routing portion is a virtual ground line. The width of the first routing portion is equal to the width of the second routing portion.

[0011] In one embodiment of the present disclosure, the first routing portion includes a first signal line and at least two first ground lines, the at least two first ground lines are respectively arranged on both sides of the first signal line, the first insulating layer covers the first signal line and exposes at least a portion of at least one first ground line.

[0012] In one embodiment of the present disclosure, at least two first grounding lines include a first sub-grounding line and a second sub-grounding line, the first sub-grounding line is located between a plurality of grounding units and the first signal line, the second sub-grounding line is located between the first signal line and the edge of the first substrate, and the first insulating layer exposes at least a portion of the second sub-grounding line.

[0013] In one embodiment of the present disclosure, the width of the second sub-ground line is greater than the width of the first sub-ground line.

[0014] In one embodiment of the present disclosure, first routing portions are respectively provided on both sides of multiple grounding units, and the first insulating layer includes two first insulating portions, which respectively cover the first signal line and the first sub-grounding line of the two first routing portions, and the area between the two first insulating portions near the edges of the multiple grounding units is an exposed area.

[0015] In one embodiment of the present disclosure, two first routing portions are spaced apart from a plurality of grounding units, two first insulating portions are located near edges of the plurality of grounding units and are respectively located between the gaps between the plurality of grounding units and the two first routing portions, and the orthographic projections of the grounding units on the first substrate are located within the orthographic projections of the exposed areas on the first substrate.

[0016] In one embodiment of the present disclosure, a first routing portion is provided on one side of multiple grounding units, and a second routing portion is provided on the other side. The first insulating layer includes a first insulating portion, which covers the first signal line and the first sub-ground line of the first routing portion. The first insulating portion is an exposed area between the edge of the multiple grounding units and the edge of the first substrate.

[0017] In one embodiment of the present disclosure, the second routing portion and the first routing portion are respectively spaced apart from the multiple grounding units, the first insulating portion is located between the gaps between the multiple grounding units and the first routing portion near the edges of the multiple grounding units, and the orthographic projections of the grounding units on the first substrate and the orthographic projections of the second routing portion on the first substrate are located within the orthographic projections of the exposed area on the first substrate.

[0018] In one embodiment of the present disclosure, each grounding unit is connected to the first sub-grounding lines on both sides respectively, and the orthographic projections of the two first insulating portions on the first substrate overlap with the orthographic projections of the multiple grounding units on the first substrate.

[0019] In one embodiment of the present disclosure, each grounding unit is respectively connected to the second routing portion and the first sub-grounding line, the first insulating portion is located between the first sub-grounding line and the second routing portion near the edge of the multiple grounding units, and the orthographic projection of the first insulating portion on the first substrate overlaps with the orthographic projection of the multiple grounding units on the first substrate.

[0020] In one embodiment of the present disclosure, the exposed area includes a plurality of openings provided in the first insulating layer, and the orthographic projection of the grounding unit on the first substrate is located within the orthographic projection of the openings on the first substrate.

[0021] In one embodiment of the present disclosure, the distances between the two first routing portions and the plurality of grounding units are equal.

[0022] In one embodiment of the present disclosure, the distance between the first routing portion and the plurality of grounding units is equal to the distance between the second routing portion and the plurality of grounding units.

[0023] In one embodiment of the present disclosure, there are multiple signal lines, and the distance between two adjacent signal lines, the distance between a first sub-ground line and an adjacent first signal line, and the distance between a second sub-ground line and an adjacent first signal line are equal.

[0024] In one embodiment of the present disclosure, the first circuit board layer group also includes a second routing layer, which is arranged on the first substrate and a side away from the first routing layer. The second routing layer and the first routing layer are connected through a first conductive structure in a first via, and the first via passes through the first routing layer and the first substrate.

[0025] In one embodiment of the present disclosure, the second routing layer includes a second routing portion, the second routing portion includes a second signal line, and the second signal line is connected to the first signal line through a first conductive structure in the first via.

[0026] In one embodiment of the present disclosure, the flexible circuit board also includes a second circuit board layer group, which is arranged on a side of the first circuit board layer group close to the second routing layer. The second circuit board layer group includes a second substrate and a third routing layer. The second substrate is connected to the second routing layer through an adhesive layer. The third routing layer is arranged on a side of the second substrate away from the second routing layer. The third routing layer is connected to the second routing layer through a second conductive structure in a second via. The second via passes through the third routing layer, the second substrate, the adhesive layer and the second routing layer.

[0027] In one embodiment of the present disclosure, the flexible circuit board further includes a second insulating layer, and the second insulating layer is provided on a side of the third wiring layer away from the second substrate.

[0028] According to another aspect of the present disclosure, a display module is provided, including the flexible circuit board provided in one aspect of the present disclosure.

[0029] According to yet another aspect of the present disclosure, a display device is provided, comprising the display module provided in one aspect of the present disclosure.

[0030] The flexible circuit board disclosed herein includes a connecting portion, which includes a first routing layer, a first insulating layer, and an electromagnetic shielding layer that are stacked. The first routing layer includes a plurality of grounding units that are spaced apart. The first routing layer digs out the portion between the grounding units, which can reduce the thickness of the connecting portion in this area and reduce the bending rebound force of the connecting portion. The first insulating layer is provided with an exposed area, the orthographic projection of the exposed area on the first substrate overlaps with the orthographic projection of the grounding unit on the first substrate, the electromagnetic shielding layer is connected to the grounding unit through the exposed area, the first insulating layer exposes at least a portion of at least one first grounding wire, the electromagnetic shielding layer is connected to the exposed portion of the first grounding wire, and the grounding unit and the first grounding wire can ensure the grounding effect of the electromagnetic shielding layer. Therefore, while ensuring the grounding effect of the electromagnetic shielding layer of the connecting portion, the flexible circuit board can also take into account the bending performance of the neck area.

[0031] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0033] FIG1 is a schematic structural diagram of a flexible circuit board according to an embodiment of the present disclosure.

[0034] FIG2 is a cross-sectional schematic diagram of a connection portion of a flexible printed circuit board according to an embodiment of the present disclosure when first wiring portions are spaced apart on both sides of a grounding structure.

[0035] FIG3 is a planar schematic diagram of a first routing layer involved in an embodiment of the present disclosure when first routing portions are spaced apart on both sides of a grounding structure.

[0036] FIG4 is a planar schematic diagram of a first routing layer and a first insulating layer involved in an embodiment of the present disclosure when first routing portions are spaced apart on both sides of a grounding structure.

[0037] FIG5 is a planar schematic diagram of the first routing layer, the first insulating layer, and the electromagnetic shielding layer involved in an embodiment of the present disclosure when the first routing portions are spaced apart on both sides of the grounding structure.

[0038] FIG6 is another cross-sectional schematic diagram of the connection portion of the flexible printed circuit board according to an embodiment of the present disclosure when first trace portions are spaced apart on both sides of the grounding structure.

[0039] FIG7 is another cross-sectional schematic diagram of the connection portion of the flexible printed circuit board according to an embodiment of the present disclosure when first wiring portions are spaced apart on both sides of the grounding structure.

[0040] FIG8 is another cross-sectional schematic diagram of the connection portion of the flexible printed circuit board according to an embodiment of the present disclosure when the first wiring portions are spaced apart on both sides of the grounding structure.

[0041] FIG9 is a cross-sectional schematic diagram of the connection portion of the flexible printed circuit board according to an embodiment of the present disclosure, when each grounding unit is connected to the first wiring portions on both sides respectively.

[0042] FIG10 is a plan view of the first routing layer according to an embodiment of the present disclosure when each grounding unit is connected to the first routing portions on both sides.

[0043] FIG11 is a planar schematic diagram of the first routing layer and the first insulating layer involved in an embodiment of the present disclosure when each grounding unit is connected to the first routing portions on both sides respectively.

[0044] FIG12 is a planar schematic diagram of the first routing layer, the first insulating layer, and the electromagnetic shielding layer involved in an embodiment of the present disclosure when each grounding unit is connected to the first routing portions on both sides respectively.

[0045] FIG13 is a cross-sectional schematic diagram of the connection portion of the flexible printed circuit board according to an embodiment of the present disclosure when a first routing portion and a second routing portion are spaced apart on both sides of the grounding structure.

[0046] FIG14 is a plan view of a first routing layer according to an embodiment of the present disclosure when a first routing portion and a second routing portion are spaced apart on both sides of a ground structure.

[0047] FIG15 is a planar schematic diagram of the first routing layer and the first insulating layer involved in an embodiment of the present disclosure when the first routing portion and the second routing portion are spaced apart on both sides of the grounding structure.

[0048] 16 is a planar schematic diagram of the first routing layer, the first insulating layer, and the electromagnetic shielding layer involved in an embodiment of the present disclosure when the first routing portion and the second routing portion are spaced apart on both sides of the grounding structure.

[0049] FIG17 is a cross-sectional schematic diagram of the connection portion of the flexible circuit board according to an embodiment of the present disclosure when each grounding unit is connected to the first routing portion and the second routing portion on both sides.

[0050] FIG18 is a plan view of the first routing layer involved in an embodiment of the present disclosure when each grounding unit is connected to the first routing portion and the second routing portion on both sides respectively.

[0051] FIG19 is a planar schematic diagram of the first routing layer and the first insulating layer involved in an embodiment of the present disclosure when each grounding unit is connected to the first routing portion and the second routing portion on both sides respectively.

[0052] FIG20 is a planar schematic diagram of the first routing layer, the first insulating layer, and the electromagnetic shielding layer involved in an embodiment of the present disclosure when each grounding unit is connected to the first routing portion and the second routing portion on both sides respectively.

[0053] FIG21 is a planar schematic diagram of the first routing layer and the first insulating layer involved in an embodiment of the present disclosure when the first routing portions are spaced apart on both sides of the grounding structure.

[0054] FIG22 is a cross-sectional schematic diagram of the connection portion of the flexible circuit board according to an embodiment of the present disclosure when the first circuit board layer group further includes a second wiring layer.

[0055] FIG. 23 is a flow chart of a process for manufacturing a flexible circuit board according to an embodiment of the present disclosure.

[0056] FIG. 24 is a schematic diagram showing a state of a connecting portion after a first conductive layer and a second conductive layer are formed on opposite sides of a first substrate.

[0057] FIG25 is a schematic diagram showing the state of the connection portion after the second conductive layer is patterned to form a second wiring layer.

[0058] FIG26 is a schematic diagram showing the connection portion after the second substrate and the second wiring layer are bonded together.

[0059] FIG27 is a schematic diagram showing the state of the connection portion after the first via hole and the second via hole are made.

[0060] FIG28 is a schematic diagram showing the state of the connecting portion after the first conductive structure is filled in the first via hole and the second conductive structure is filled in the second via hole.

[0061] FIG29 is a schematic diagram showing the state of the connection portion after the first routing layer and the third routing layer are formed.

[0062] FIG30 is a schematic diagram showing the state of the connection portion after the first insulating layer and the second insulating layer are formed.

[0063] Description of reference numerals:

[0064] 1. Main body, 2. Connecting portion, 21. Second circuit board layer group, 211. First substrate, 212. First routing layer, 2121. Grounding structure, 2122. Grounding unit, 2123. First routing portion, 2124. First signal line, 2125. First sub-ground line, 2126. Second sub-ground line, 2127. Second routing portion, 213. Second routing layer, 2131. Second signal line, 2132. Third sub-ground line, 2133. Fourth sub-ground line, 2134 , third grounding portion, 2135, fourth grounding portion, 22, first circuit board layer group, 221, second substrate, 222, third routing layer, 23, first insulating layer, 231, first insulating portion, 232, exposed area, 2321, opening, 24, electromagnetic shielding layer, 25, adhesive layer, 26, first conductive structure, 27, second conductive structure, 28, second insulating layer, 291, first via, 292, second via, 3, first conductive layer, 4, second conductive layer, 5, third conductive layer. DETAILED DESCRIPTION

[0065] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0066] Although relative terms such as "upper" and "lower" are used in this specification to describe the relationship of one illustrated component to another, these terms are used herein for convenience only, such as in accordance with the orientation of the illustrations in the accompanying drawings. It will be understood that if the illustrated device were flipped upside down, the component described as "upper" would become the component "lower." When a structure is referred to as "on" another structure, this may mean that the structure is integrally formed with the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via the other structure.

[0067] The terms "a", "an", "the", "said" 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 express open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used only as labels and are not intended to limit the quantity of their objects.

[0068] The embodiment of the present disclosure provides a flexible circuit board. As shown in Figures 1 to 22, the flexible circuit board includes a connecting portion 2 extending along a first direction, the connecting portion 2 includes a first circuit board layer group 22, a first insulating layer 23 and an electromagnetic shielding layer 24, the first circuit board layer group 22 includes a first substrate 211 and a first routing layer 212, the first routing layer 212 is provided on one side of the first substrate 211, the first routing layer 212 includes a plurality of grounding units 2122 spaced apart along the first direction, a first routing portion 2123 is provided on one side of the plurality of grounding units 2122, and the first routing portion 2123 includes a first grounding unit 2122. line; the first insulating layer 23 is arranged on the side of the first routing layer 212 away from the first substrate 211, and the first insulating layer 23 is provided with an exposed area 232, the orthographic projection of the exposed area 232 on the first substrate 211 overlaps with the orthographic projection of the grounding unit 2122 on the first substrate 211, and the first insulating layer 23 exposes at least a portion of the first grounding line; the electromagnetic shielding layer 24 is arranged on the side of the first insulating layer 23 away from the first substrate 211, and the electromagnetic shielding layer 24 is connected to the grounding unit 2122 through the exposed area 232, and is connected to the exposed portion of the first grounding line.

[0069] The connection portion 2 of the flexible circuit board comprises a stacked first routing layer 212, a first insulating layer 23, and an electromagnetic shielding layer 24. The first routing layer 212 includes multiple grounding units 2122. The first routing layer 212 is hollowed out between the grounding units 2122 to reduce the thickness of the connection portion 2 in this area, thereby lowering the bending rebound force of the connection portion 2. The first insulating layer 23 has an exposed area 232, the orthographic projection of the exposed area 232 on the first substrate 211 overlapping the orthographic projection of the grounding units 2122 on the first substrate 211. The electromagnetic shielding layer 24 is connected to the grounding units 2122 via the exposed area 232, ensuring the grounding effect of the electromagnetic shielding layer 24. Therefore, the flexible circuit board can ensure the grounding effect of the electromagnetic shielding layer 24 in the connection portion 2 while also taking into account the bending performance of the connection portion 2.

[0070] The flexible circuit board involved in the embodiment of the present disclosure is described in detail below with reference to specific examples.

[0071] As shown in Figure 1, the flexible circuit board includes a main body 1 and a connecting portion 2. One end of the connecting portion 2 is connected to the edge of the main body 1, and the other end is connected to the mainboard of the display device. The connecting portion 2 extends along a first direction. As shown in Figures 2 and 3, the connecting portion 2 includes a first circuit board layer group 22. The first circuit board layer group 22 includes a first substrate 211 and a first routing layer 212. The first routing layer 212 is disposed on one side of the first substrate 211 and includes a grounding structure 2121. First routing portions 2123 are provided on both sides of the grounding structure 2121 along a second direction. The first routing portions 2123 are used to connect to the binding portion of the display panel. The width W1 of the first routing portions 2123 on both sides is the same, and the distance between the two first routing portions 2123 and the multiple grounding units 2122 is equal. This prevents uneven force on the connecting portion 2 when it is bent, which may cause delamination between layers.

[0072] It should be noted that the second direction is perpendicular to the first direction. The first direction is the x direction shown in FIG3 , and the second direction is the y direction shown in FIG3 .

[0073] The first routing portion 2123 includes two first signal lines 2124. A first ground line is disposed on either side of each of the two first signal lines 2124. The first ground lines shield the signals of the two first signal lines 2124 of the first routing portion 2123, preventing mutual interference between the signals of the two first routing portions 2123. The two first ground lines include a first sub-ground line 2125 and a second sub-ground line 2126. The first sub-ground line 2125 is located between the multiple ground units 2122 and the first signal lines 2124, while the second sub-ground line 2126 is located between the first signal lines 2124 and the edge of the first substrate 211.

[0074] The ground structure 2121 may include multiple ground units 2122 spaced apart along a first direction, with two first sub-ground lines 2125 spaced apart on either side of the multiple ground units 2122. The first routing layer 212 is hollowed out between two adjacent ground units 2122, as well as between a ground unit 2122 and the two first sub-ground lines 2125. Two first signal lines 2124 are sequentially arranged on the side of the first sub-ground line 2125 away from the ground unit 2122. A second sub-ground line 2126 is arranged outside the first signal line 2124 farthest from the multiple ground units 2122. The two first sub-ground lines 2125 are equidistant from the multiple ground units 2122.

[0075] It is understood that the grounding units 2122 are island-shaped structures in the first routing layer 212, with the portions of the first routing layer 212 surrounding each grounding unit 2122 being hollowed out. To facilitate mask pattern processing and reduce the cost of patterning the first routing layer 212 to form the grounding units 2122, in this embodiment, the shape of the grounding units 2122 is set to a regular shape, such as a rectangle. Of course, the grounding units 2122 can also be set to other shapes such as circles, pentagons, triangles, etc., which are not listed here. Furthermore, the grounding structure 2121 can also be configured to have equal spacing between any adjacent grounding units 2122.

[0076] The two first signal lines 2124, the first sub-ground line 2125 and the second sub-ground line 2126 all extend along the first direction. Along the first direction, the widths of the first signal line 2124 at all parts are equal, the widths of the first sub-ground line 2125 at all parts are equal, and the widths of the second sub-ground line 2126 at all parts are equal. The width of the first sub-ground line 2125 and the width of the second sub-ground line 2126 are greater than the width of the first signal line 2124, which can achieve a better grounding effect.

[0077] As shown in FIG4 , the connection portion 2 further includes a first insulating layer 23, which is disposed on a side of the first routing layer 212 away from the first substrate 211. The first insulating layer 23 includes two first insulating portions 231, which respectively cover the first signal lines 2124 of the two first routing portions 2123 and expose at least a portion of the ground structure 2121. Specifically, the edges of the first insulating portions 231 can be located on the surfaces of the multiple ground units 2122, or between the first signal lines 2124 and the multiple ground units 2122.

[0078] As shown in Figure 5 , the edge of the first insulating portion 231 is located between the first signal line 2124 and the multiple grounding units 2122. An exposed area 232 is formed between the edges of the two first insulating portions 231 near the multiple grounding units 2122. It is understood that the exposed area 232 is in the form of an open opening 2321. The exposed area 232 can extend through the bend of the connecting portion 2 along the first direction, or it can extend through the entire connecting portion 2 along the first direction. The orthographic projection of the grounding units 2122 on the first substrate 211 is located within the orthographic projection of the exposed area 232 on the first substrate 211.

[0079] An electromagnetic shielding layer 24 is provided on a side of the first insulating layer 23 away from the first substrate 211. The electromagnetic shielding layer 24 is connected to the grounding structure 2121 via an exposed area 232. The area of ​​the electromagnetic shielding layer 24 can be the same as that of the first substrate 211. As shown in the figure, to ensure the grounding effect of the electromagnetic shielding layer 24, the edges of the two first insulating portions 231 near the multiple grounding units 2122 are located between the gaps between the multiple grounding units 2122 and the two first sub-grounding lines 2125.

[0080] In this way, the electromagnetic shielding layer 24 covers the surface of the grounding unit 2122 away from the first substrate 211 and the side surface of the grounding unit 2122, thereby providing a tighter connection between the electromagnetic shielding layer 24 and the grounding unit 2122. It should be noted that the side surface of the grounding unit 2122 is perpendicularly connected between the surface of the grounding unit 2122 close to the first substrate 211 and the surface of the grounding unit 2122 away from the first substrate 211.

[0081] Providing an exposed area 232 on the first insulating layer 23 and locating multiple grounding units 2122 within the exposed area 232 can reduce the thickness of the connecting portion 2 in the area where the grounding structure 2121 is located, thereby reducing the space occupied by the grounding structure 2121 in the display device. During bending of the flexible printed circuit board connecting portion 2, the connecting portion 2 is more easily bent in the thinner area, reducing the bending rebound force of the connecting portion 2.

[0082] The first insulating layer 23 digs out the outer portion of the grounding unit 2122, so that in the area where the grounding structure 2121 is located, the thickness of the outer area of ​​the grounding unit 2122 is less than the thickness of the area where the grounding unit 2122 is located. Even if the second sub-grounding line 2126 realizes the grounding of the electromagnetic shielding layer 24, when the grounding structure 2121 is not set in the part of the two first routing parts 2123, the first routing layer 212 and the first insulating layer 23 are removed from the outer periphery of the grounding unit 2122. Compared with the case where the first insulating layer 23 covers the entire surface, the thickness and bending rebound force of the area are still reduced. The spacing between adjacent grounding units 2122 can be set to be greater than the size of the grounding unit 2122 along the first direction, which can increase the area of ​​the thinnest thickness area. Further reduce the thickness of the connecting portion 2 in the outer area of ​​the grounding unit 2122, and reduce the rebound force of the bending connecting portion 2 in the outer area of ​​the grounding unit 2122.

[0083] As shown in Figures 2, 6, and 7, to better ensure the grounding effect of the electromagnetic shielding layer 24, the first insulating portion 231 exposes at least a portion of at least one first grounding line. As shown in Figure 6, the first insulating portion 231 can expose the first sub-grounding line 2125, and the electromagnetic shielding layer 24 is connected to the exposed portion of the first sub-grounding line 2125. The width of the exposed portion of the first sub-grounding line 2125 is d2. As shown in Figure 2, the first insulating portion 231 can also expose the second sub-grounding line 2126. The electromagnetic shielding layer 24 is connected to the exposed portion of the second sub-grounding line 2126. The width of the exposed portion of the second sub-grounding line 2126 is d1. As shown in Figure 7, the first insulating portion 231 can also expose both the first sub-grounding line 2125 and the second sub-grounding line 2126. The electromagnetic shielding layer 24 is connected to both the exposed portions of the first sub-grounding line 2125 and the exposed portions of the second sub-grounding line 2126, thereby better ensuring the grounding effect of the electromagnetic shielding layer 24. The width d2 of the exposed portion of the first sub-ground line 2125 may be equal to the width d1 of the exposed portion of the second sub-ground line 2126 .

[0084] As shown in Figures 7 and 8 , the first insulating portion 231 can expose a portion of the first ground line or the entire first ground line. When the first insulating portion 231 partially exposes the first sub-ground line 2125, the edges of the two first insulating portions 231 near the multiple grounding units 2122 are located between the two sides of the first sub-ground line 2125. When the first insulating portion 231 exposes the entire first sub-ground line 2125, d2 represents the width of the first sub-ground line 2125, and the edges of the two first insulating portions 231 near the multiple grounding units 2122 are located between the first sub-ground line 2125 and the first signal line 2124. When the first insulating portion 231 exposes part of the second sub-grounding line 2126, the two first insulating portions 231 are located between the two sides of the second sub-grounding line 2126 away from the edges of the multiple grounding units 2122. When the first insulating portion 231 exposes the entire first sub-grounding line 2125, the two first insulating portions 231 are located between the second sub-grounding line 2126 and the first signal line 2124 close to the edges of the multiple grounding units 2122, and d1 is the width of the second sub-grounding line 2126.

[0085] Because the widths of first and second sub-grounding lines 2125 and 2126 are relatively small, and due to process tolerances during the formation of first insulating layer 23, exposing them directly could expose first signal line 2124, potentially impacting signal transmission. First insulating portion 231 partially exposes the first grounding line, ensuring grounding of electromagnetic shielding layer 24 while completely covering first signal line 2124, thus preventing signal transmission.

[0086] In addition, the width of the first sub-grounding line 2125 and the width of the second sub-grounding line 2126 can be increased to allow for a larger process tolerance range and reduce the difficulty in forming the first insulating layer 23. However, since increasing the width of the first sub-grounding line 2125 will affect the routing of the first signal line 2124, the width of the second sub-grounding line 2126 of the two first routing portions 2123 can be increased, making the width of the second sub-grounding line 2126 greater than the width of the first sub-grounding line 2125. The first insulating portion 231 can expose the increased portion of the second sub-grounding line 2126, reserving grounding space for the electromagnetic shielding layer 24 on the second sub-grounding line 2126.

[0087] As shown in Figures 9 to 12 , the difference from Figures 2 to 5 lies in that each grounding unit 2122 is connected to the first sub-grounding lines 2125 on both sides, forming a mesh structure with the multiple grounding units 2122 and the first sub-grounding lines 2125. This increases the area of ​​the grounding structure 2121 and provides a better electromagnetic grounding effect. The two first insulating portions 231 respectively cover the first sub-grounding lines 2125 of the two first routing portions 2123 . The orthographic projections of the first insulating portions 231 on the first substrate 211 overlap with the orthographic projections of the multiple grounding units 2122 on the first substrate 211.

[0088] The flexible printed circuit board's connection portion 2 may also have single-sided signal routing, as shown in Figures 13 to 16. The grounding structure 2121 is the same as that shown in the figures, including multiple grounding units 2122 spaced apart along a first direction. A first routing portion 2123 may be provided on one side of the grounding structure 2121. To prevent separation between layers when the connection portion 2 is bent, a second routing portion 2127 may be provided on the other side of the grounding structure 2121. The width of the first routing portion 2123 is equal to the width of the second routing portion 2127. The distances between the first routing portion 2123 and the multiple grounding units 2122 and the distances between the second routing portion 2127 and the multiple grounding units 2122 are equal.

[0089] The first routing portion 2123 includes two first signal lines 2124 and two first ground lines. The two first ground lines include a first sub-ground line 2125 and a second sub-ground line 2126. The first sub-ground line 2125 is located between the multiple ground units 2122 and the first signal lines 2124. The second sub-ground line 2126 is located between the first signal lines 2124 and the edge of the first substrate 211. The width of the second sub-ground line 2126 is greater than that of the first sub-ground line 2125. The second routing portion 2127 is a virtual ground line and is not connected to the binding portion of the display panel.

[0090] The first insulating layer 23 includes a first insulating portion 231, which covers the first signal line 2124 and the first sub-ground line 2125 of the first routing portion 2123. The edge of the first insulating portion 231 close to the multiple grounding units 2122 is located between the first sub-ground line 2125 and the multiple grounding units 2122. The edge of the first insulating portion 231 away from the multiple grounding units 2122 is located between the two sides of the second sub-ground line 2126. An exposed area 232 is formed between the edge of the first insulating portion 231 close to the multiple grounding units 2122 and the edge of the first substrate 211.

[0091] The orthographic projection of the second routing portion 2127 on the first substrate 211 is located within the orthographic projection of the exposed area 232 on the first substrate 211, and the orthographic projection of the grounding unit 2122 on the first substrate 211 is located within the orthographic projection of the exposed area 232 on the first substrate 211. The electromagnetic shielding layer 24 is disposed on a side of the first insulating layer 23 away from the first substrate 211. The electromagnetic shielding layer 24 is connected to the exposed portion of the second sub-ground line 2126, the multiple grounding units 2122, and the virtual ground line.

[0092] As shown in Figures 17 to 20 , the difference from Figures 9 to 12 lies in that each grounding unit 2122 is connected to the second routing portion and the first sub-grounding line 2125, respectively. This creates a mesh structure with the multiple grounding units 2122, the first sub-grounding line 2125, and the second routing portion. This increases the area of ​​the grounding structure 2121 and provides a better electromagnetic grounding effect. The edge of the first insulating portion 231, near the multiple grounding units 2122, is located between the first sub-grounding line 2125 and the second routing portion 2127. The orthographic projection of the first insulating portion 231 on the first substrate 211 overlaps with the orthographic projections of the multiple grounding units 2122 on the first substrate 211. In other words, the orthographic projections of the grounding units 2122 on the first substrate 211 are located within the orthographic projection of the exposed area 232 on the first substrate 211, and the orthographic projection of the second routing portion 2127 on the first substrate 211 is located within the orthographic projection of the exposed area 232 on the first substrate 211. It can be understood that, while the first insulating portion 231 covers the first sub-grounding line 2125 , it is partially overlapped with a surface of the grounding unit 2122 away from the first substrate.

[0093] As shown in FIG. 21 , in another possible embodiment, the exposed area 232 includes a plurality of openings 2321 provided in the first insulating layer 23, and the orthographic projection of the grounding unit 2122 on the first substrate 211 is located within the orthographic projection of the openings 2321 on the first substrate 211. Specifically, the orthographic projection of the grounding unit 2122 on the first substrate 211 may coincide with the orthographic projection of the openings 2321 on the first substrate 211. At least a portion of each of the two sides of the first insulating layer 23 in the second direction is exposed.

[0094] Second sub-ground line 2126 .

[0095] The advantage of this arrangement is that the first insulating layer 23 is a single layer, and there is no risk of the first signal line 2124 being exposed, and there is no need to consider process tolerances. Furthermore, the portion where the first insulating layer 23 overlaps with the grounding unit 2122 is dug out, which can also reduce the thickness of the area where the grounding unit 2122 of the connecting portion 2 is located, thereby reducing the space occupied by the entire display device. Furthermore, although a first insulating layer 23 is provided between two adjacent grounding units 2122, while ensuring the grounding effect of the electromagnetic shielding layer 24, the bending performance of the connecting portion 2 is not affected. The thickness of the first routing layer 212 is typically less than that of the first insulating layer 23, and therefore the bending performance of the connecting portion 2 in this area can be reduced.

[0096] As shown in Figure 22, when the connection portion 2 of the flexible circuit board is routed on one side, the first circuit board layer group 22 also includes a second routing layer 213. The second routing layer 213 is provided on the side of the first substrate 211 away from the first routing layer 212. The second routing layer 213 may include a second routing portion 2127. The second routing portion 2127 may include a second signal line 2131. The second signal line 2131 is connected to the first signal line 2124 via the first conductive structure 26 within the first via 291. The second signal line 2131 forms a parallel structure with the first signal line 2124 to reduce resistance during signal transmission. Two second signal lines 2131 can be provided, and the two second signal lines 2131 are connected through the first conductive structures 26 within the two first vias 291.

[0097] Second ground lines can be provided on both sides of the second signal line 2131. The second ground line can include a third sub-ground line 2132 and a fourth sub-ground line 2133. The third sub-ground line 2132 is located on the side of the second signal line 2131 closer to the ground structure 2121, and the fourth sub-ground line 2133 is located on the side of the second signal line 2131 farther from the ground structure 2121, thereby shielding the signal carried by the second signal line 2131. It should be noted that because the second signal line 2131 is connected in parallel with the first signal line 2124, the second signal line 2131 and the first signal line 2124 carry the same signal.

[0098] The second signal line 2131, the third sub-ground line 2132 and the fourth sub-ground line 2133 constitute a third ground portion 2134. In order to ensure that the bending rebound force provided by the second routing layer 213 on both sides of the ground structure 2121 is equal, a fourth ground portion 2135 is set on the other side of the ground structure 2121. The width of the fourth ground portion 2135 can be set to be equal to that of the third ground portion 2134.

[0099] As shown in Figure 30, for the wearable display module, the flexible circuit board also includes a second circuit board layer group 21, which is arranged on the side of the first circuit board layer group 22 near the second routing layer 213. The second circuit board layer group 21 includes a second substrate 221 and a third routing layer 222. The third routing layer 222 is connected to the second routing layer 213 via an adhesive layer 25. The third routing layer 222 is set in most of the area on the side of the second substrate 221 away from the second routing layer 213 to shield signal interference. The third routing layer 222 is connected to the second routing layer 213 through a second conductive structure 27 in a second via. The second via passes through the third routing layer 222, the second substrate 221, the adhesive layer 25, and the second routing layer 213. In addition, the flexible circuit board may also include a second insulating layer 28, which is arranged on the side of the third routing layer 222 away from the second substrate 221.

[0100] Currently, when forming first via 291, a second via 3 is formed on the surface of first conductive layer 292 on the surface of first routing layer 212. When forming the second via, a second conductive layer 4 is also formed on the surface of third routing layer 222. The presence of first conductive layer 292, second via 3, and second conductive layer 4 increases the thickness of the flexible circuit board and the display module, squeezing space within the display device. As shown in the figure, first conductive structure 26 is formed within first via 291, and second conductive structure 27 is formed within the second via. This eliminates the need for first conductive layer 292, second via 3, and second conductive layer 4, reducing the thickness of the flexible circuit board.

[0101] The following describes the manufacturing process of the flexible circuit board involved in the embodiment of the present disclosure. As shown in Figure 23, the manufacturing process of the flexible circuit board may include:

[0102] Step S10 , forming a second via hole 3 of the first conductive layer 292 and a second conductive layer 4 on opposite sides of the first substrate 211 , as shown in FIG. 24 .

[0103] In step S20 , the second conductive layer 4 is patterned to form a second wiring layer 213 , as shown in FIG. 25 .

[0104] In step S30 , the second substrate 221 and the second trace layer 213 of the second circuit board layer group 21 are bonded together using the adhesive layer 25 , as shown in FIG. 26 .

[0105] Step S40, making a first via hole 291 through the first conductive layer 292 and the first substrate 211, and making a second via hole through the third routing layer 222, the second substrate 221, the adhesive layer 25 and the second routing layer 213, as shown in FIG27.

[0106] In step S50 , the first conductive structure 26 is filled in the first via hole 291 , and the second conductive structure 27 is filled in the second via hole, as shown in FIG. 28 .

[0107] In step S60 , the second via hole 3 of the first conductive layer 292 is patterned to form a first wiring layer 212 , and the third conductive layer 5 is patterned to form a third wiring layer 222 , as shown in FIG. 29 .

[0108] In step S70 , a first insulating layer 23 is attached to the surface of the first wiring layer 212 , and a second insulating layer 28 is attached to the surface of the third wiring layer 222 , as shown in FIG30 .

[0109] The present disclosure also provides a display module. The display module may include a display panel according to any of the above embodiments of the present disclosure, wherein the main portion 1 of the flexible circuit board is typically attached to the non-display surface of the display panel, and the connecting portion 2 is bent from the side of the display panel to the display surface of the display panel and is bonded to the display panel.

[0110] The present disclosure also provides a display device. The display device may include the display module described above in the present disclosure. The specific structure and beneficial effects of the display module have been described in detail above and will not be repeated here.

[0111] It should be noted that, in addition to the display module, the display device also includes other necessary components and components, such as a housing, a power cord, etc. Those skilled in the art can make corresponding supplements based on the specific usage requirements of the display device, which will not be elaborated here.

[0112] When the flexible circuit board is of the structure shown in the figure, the display device can be a traditional electronic device, such as a mobile phone, a computer, a television, and a camcorder, or an emerging wearable device, such as a virtual reality device and an augmented reality device, which are not listed here one by one.

[0113] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A flexible circuit board, wherein: The invention comprises a connecting portion extending along a first direction, wherein the connecting portion comprises: A first circuit board layer group includes a first substrate and a first routing layer, wherein the first routing layer is arranged on one side of the first substrate, the first routing layer includes a plurality of grounding units arranged at intervals along the first direction, a first routing portion is arranged on one side of the plurality of grounding units, and the first routing portion includes a first grounding wire; A first insulating layer is provided on a side of the first wiring layer away from the first substrate, the first insulating layer is provided with an exposed area, an orthographic projection of the exposed area on the first substrate overlaps with an orthographic projection of the grounding unit on the first substrate, and the first insulating layer exposes at least a portion of the first grounding line; The electromagnetic shielding layer is arranged on a side of the first insulating layer away from the first substrate, and the electromagnetic shielding layer is connected to the grounding unit through the exposed area and is connected to the exposed part of the first grounding line.

2. The flexible circuit board according to claim 1, wherein: A first routing portion is provided on one side of the multiple grounding units, and a first routing portion or a second routing portion is provided on the other side. The first routing portion is used to bind to the display panel, and the second routing portion is a virtual ground line. The width of the first routing portion is equal to the width of the second routing portion.

3. The flexible circuit board according to claim 2, wherein: The first routing portion includes a first signal line and at least two first grounding lines, the at least two first grounding lines are respectively arranged on both sides of the first signal line, and the first insulating layer at least covers the first signal line and exposes at least a portion of at least one of the first grounding lines.

4. The flexible circuit board according to claim 3, wherein: The at least two first grounding lines include a first sub-grounding line and a second sub-grounding line, the first sub-grounding line is located between the multiple grounding units and the first signal line, the second sub-grounding line is located between the first signal line and the edge of the first substrate, and the first insulating layer exposes at least a portion of the second sub-grounding line.

5. The flexible circuit board according to claim 4, wherein: The width of the second sub-ground line is greater than that of the first sub-ground line.

6. The flexible circuit board according to claim 4, wherein: First routing parts are respectively provided on both sides of the multiple grounding units, and the first insulating layer includes two first insulating parts, which respectively cover the first signal line and the first sub-grounding line of the two first routing parts, and the exposed area is between the two first insulating parts near the edges of the multiple grounding units.

7. The flexible circuit board according to claim 6, wherein: The two first routing portions are spaced apart from the multiple grounding units, the edges of the two first insulating portions close to the multiple grounding units are respectively located between the gaps between the multiple grounding units and the two first routing portions, and the orthographic projection of the grounding unit on the first substrate is located within the orthographic projection of the exposed area on the first substrate.

8. The flexible circuit board according to claim 4, wherein: A first routing portion is provided on one side of the multiple grounding units, and a second routing portion is provided on the other side. The first insulating layer includes a first insulating portion, which covers a first signal line and a first sub-grounding line of the first routing portion. The exposed area is between the edge of the first insulating portion close to the multiple grounding units and the edge of the first substrate.

9. The flexible circuit board according to claim 8, wherein: The second routing portion and the first routing portion are respectively spaced apart from the multiple grounding units, the edge of the first insulating portion close to the multiple grounding units is located between the gaps between the multiple grounding units and the first routing portion, and the orthographic projection of the grounding unit on the first substrate and the orthographic projection of the second routing portion on the first substrate are located within the orthographic projection of the exposed area on the first substrate.

10. The flexible circuit board according to claim 6, wherein: Each of the grounding units is connected to the first sub-grounding lines on both sides respectively, and the orthographic projections of the two first insulating portions on the first substrate overlap with the orthographic projections of the plurality of grounding units on the first substrate.

11. The flexible circuit board according to claim 8, wherein: Each of the grounding units is respectively connected to the second routing portion and the first sub-grounding wire, the first insulating portion is located between the first sub-grounding wire and the second routing portion near the edge of the multiple grounding units, and the orthographic projection of the first insulating portion on the first substrate overlaps with the orthographic projection of the multiple grounding units on the first substrate.

12. The flexible circuit board according to claim 4, wherein: The exposed area includes a plurality of openings provided in the first insulating layer, and an orthographic projection of the grounding unit on the first substrate is located within an orthographic projection of the openings on the first substrate.

13. The flexible circuit board according to claim 6, wherein: The distances between the two first routing portions and the plurality of grounding units are equal.

14. The flexible circuit board according to claim 8, wherein: The distance between the first routing portion and the plurality of grounding units is equal to the distance between the second routing portion and the plurality of grounding units.

15. The flexible circuit board according to claim 4, wherein: There are a plurality of signal lines, and the distance between two adjacent signal lines, the distance between the first sub-ground line and an adjacent first signal line, and the distance between the second sub-ground line and an adjacent first signal line are equal.

16. The flexible circuit board according to claim 3, wherein: The first circuit board layer group also includes a second routing layer, which is arranged on the first substrate and a side away from the first routing layer. The second routing layer is connected to the first routing layer through a first conductive structure in a first via, and the first via passes through the first routing layer and the first substrate.

17. The flexible circuit board according to claim 16, wherein: The second routing layer includes a second routing portion, the second routing portion includes a second signal line, and the second signal line is connected to the first signal line through a first conductive structure in a first via hole.

18. The flexible circuit board according to claim 16, wherein: The flexible circuit board also includes a second circuit board layer group, which is arranged on a side of the first circuit board layer group close to the second routing layer, and the second circuit board layer group includes a second substrate and a third routing layer, the second substrate is connected to the second routing layer through an adhesive layer, and the third routing layer is arranged on a side of the second substrate away from the second routing layer, and the third routing layer is connected to the second routing layer through a second conductive structure in a second via, and the second via passes through the third routing layer, the second substrate, the adhesive layer and the second routing layer.

19. The flexible circuit board according to claim 18, wherein: The flexible circuit board further includes a second insulating layer, and the second insulating layer is arranged on a side of the third wiring layer away from the second substrate.

20. A display module, wherein: A flexible circuit board comprising any one of claims 1 to 19.

21. A display device, wherein: Includes the display module described in claim 20.

Images