Flexible circuit board, display module and display device

Abstract

The invention relates to a flexible circuit board, the flexible circuit board comprises a connecting part, the connecting part comprises a first wiring layer, a first insulating layer and an electromagnetic shielding layer which are arranged in a stacked manner, the part between grounding units is excavated from the first wiring layer, the thickness of the connecting part in the area can be reduced, and the bending rebound force of the connecting part is reduced. The first insulating layer is provided with an exposed area, the electromagnetic shielding layer is connected with the grounding unit through the exposed area, at least part of at least one first grounding wire is exposed out of the first insulating layer, the electromagnetic shielding layer is connected with the exposed part of the first grounding wire, and the grounding unit and the first grounding wire can guarantee the grounding effect of the electromagnetic shielding layer. Therefore, the flexible circuit board can ensure the grounding effect of the electromagnetic shielding layer of the connecting part, and can take the bending performance of the connecting part into consideration. The invention further provides a display module comprising the flexible circuit board and a display device comprising the display module.

Description

Technical Field

[0001] 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

[0002] 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.

[0003] 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.

[0004] 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 the prior art known to ordinary technicians in the field. Summary of the invention

[0005] The purpose of the present disclosure is to overcome the deficiencies of the above-mentioned prior art and to provide a flexible circuit board, a display module and a display device.

[0006] 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 arranged at intervals along the first direction, a first routing portion being arranged 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, and 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.

[0007] 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.

[0008] 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.

[0009] 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 an edge of the first substrate, and the first insulating layer exposes at least a portion of the second sub-grounding line.

[0010] 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.

[0011] In one embodiment of the present disclosure, first routing portions are respectively provided on both sides of the 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 there is an exposed area between the two first insulating portions near the edges of the multiple grounding units.

[0012] 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 gaps between the plurality of 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.

[0013] In one embodiment of the present disclosure, 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, the first insulating portion covers the first signal line and the first sub-grounding line of the first routing portion, and the edge of the first insulating portion close to the multiple grounding units and the edge of the first substrate is an exposed area.

[0014] In one embodiment of the present disclosure, the second routing portion and the first routing portion are respectively spaced apart from the plurality of grounding units, the first insulating portion is located between the gaps between the plurality of grounding units and the first routing portion near the edge of the plurality of grounding units, 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.

[0015] 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 plurality of grounding units on the first substrate.

[0016] In one embodiment of the present disclosure, each grounding unit 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.

[0017] 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.

[0018] In one embodiment of the present disclosure, the distances between the two first routing portions and the plurality of grounding units are equal.

[0019] 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.

[0020] 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.

[0021] 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 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.

[0022] 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.

[0023] 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, 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, 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, and the second via passes through the third routing layer, the second substrate, the adhesive layer and the second routing layer.

[0024] In one embodiment of the present disclosure, the flexible circuit board further includes a second insulating layer, and the second insulating layer is disposed on a side of the third wiring layer away from the second substrate.

[0025] 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.

[0026] According to another aspect of the present disclosure, a display device is provided, including the display module provided by one aspect of the present disclosure.

[0027] The flexible circuit board disclosed in the present invention includes a connecting part, and the connecting part includes a first routing layer, a first insulating layer and an electromagnetic shielding layer which are stacked. The first routing layer includes a plurality of grounding units which are spaced apart. The first routing layer digs out the parts between the grounding units, which can reduce the thickness of the connecting part in this area and reduce the bending rebound force of the connecting part. The first insulating layer is provided with an exposed area, and 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 part of at least one first grounding wire, and the electromagnetic shielding layer is connected to the exposed part of the first grounding wire. The grounding unit and the first grounding wire can ensure the grounding effect of the electromagnetic shielding layer. Therefore, the flexible circuit board can take into account the bending performance of the neck area while ensuring the grounding effect of the electromagnetic shielding layer of the connecting part.

[0028] 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 present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings herein are incorporated into the specification 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 accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0030] Figure 1 It is a schematic diagram of the structure of the flexible circuit board involved in the embodiment of the present disclosure.

[0031] Figure 2 A schematic cross-sectional view 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.

[0032] Figure 3 A schematic plan view 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.

[0033] Figure 4 A schematic plan view 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.

[0034] Figure 5 A schematic plan view of a first routing layer, a first insulating layer, and an electromagnetic shielding layer involved in an embodiment of the present disclosure when first routing portions are spaced apart on both sides of a grounding structure.

[0035] Figure 6Another cross-sectional schematic diagram of the connection portion of the flexible printed circuit board involved in the embodiment of the present disclosure is when the first wiring portions are spaced apart on both sides of the grounding structure.

[0036] Figure 7 Another cross-sectional schematic diagram of the connection portion of the flexible printed circuit board involved in the embodiment of the present disclosure is when the first wiring portions are spaced apart on both sides of the grounding structure.

[0037] Figure 8 Another cross-sectional schematic diagram of the connection portion of the flexible printed circuit board involved in the embodiment of the present disclosure is when the first wiring portions are spaced apart on both sides of the grounding structure.

[0038] Fig. 9 It is a cross-sectional schematic diagram of the connection portion of the flexible circuit board involved in the embodiment of the present disclosure when each grounding unit is respectively connected to the first wiring portions on both sides.

[0039] Fig.10 It is a plan view of the first routing layer involved in the embodiment of the present disclosure when each grounding unit is respectively connected to the first routing portions on both sides.

[0040] Fig.11 It is a plan view of the first routing layer and the first insulating layer involved in the embodiment of the present disclosure when each grounding unit is respectively connected to the first routing portions on both sides.

[0041] Fig.12 It is a plan view of the first routing layer, the first insulating layer and the electromagnetic shielding layer involved in the embodiment of the present disclosure when each grounding unit is respectively connected to the first routing portions on both sides.

[0042] Fig.13 A schematic cross-sectional view of the connection portion of the flexible circuit board involved in an embodiment of the present disclosure when a first routing portion and a second routing portion are spaced apart on two sides of a grounding structure.

[0043] Fig.14 A schematic plan view of a first routing layer involved in an embodiment of the present disclosure when a first routing portion and a second routing portion are spaced apart on two sides of a grounding structure.

[0044] Fig.15 A schematic plan view of a first routing layer and a first insulating layer involved in an embodiment of the present disclosure when a first routing portion and a second routing portion are spaced apart on two sides of a grounding structure.

[0045] Fig.16 A schematic plan view of a first routing layer, a first insulating layer, and an electromagnetic shielding layer involved in an embodiment of the present disclosure when a first routing portion and a second routing portion are spaced apart on both sides of a grounding structure.

[0046] Fig.17It is a cross-sectional schematic diagram of the connection portion of the flexible circuit board involved in the embodiment of the present disclosure when each grounding unit is respectively connected to the first routing portion and the second routing portion on both sides.

[0047] Fig.18 It is a plan view of the first routing layer involved in the embodiment of the present disclosure when each grounding unit is respectively connected to the first routing portion and the second routing portion on both sides.

[0048] Fig.19 It is a plan view of the first routing layer and the first insulating layer involved in the embodiment of the present disclosure when each grounding unit is respectively connected to the first routing portion and the second routing portion on both sides.

[0049] Fig. 20 It is a plan view of the first routing layer, the first insulating layer and the electromagnetic shielding layer involved in the embodiment of the present disclosure when each grounding unit is respectively connected to the first routing portion and the second routing portion on both sides.

[0050] Fig.21 A schematic plan view 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.

[0051] Fig. 22 A schematic cross-sectional view of the connection portion of the flexible circuit board involved in the embodiment of the present disclosure when the first circuit board layer group also includes a second wiring layer.

[0052] Fig.23 The present invention is a flowchart of a process for manufacturing a flexible circuit board according to an embodiment of the present invention.

[0053] Fig.24 It is a schematic diagram of the state of the connecting part after the first conductive layer and the second conductive layer are respectively formed on two opposite sides of the first substrate.

[0054] Fig.25 A schematic diagram of the state of the connection portion after the second conductive layer is patterned to form the second wiring layer.

[0055] Fig.26 It is a schematic diagram of the state of the connection part after the second substrate and the second wiring layer are bonded together.

[0056] Fig. 27 It is a schematic diagram of the state of the connecting part after making the first via hole and the second via hole.

[0057] Fig.28 It is a schematic diagram of the state of the connecting part after the first conductive structure is filled in the first via hole and the second conductive structure is filled in the second via hole.

[0058] Fig.29 It is a schematic diagram of the state of the connection part after the first routing layer and the third routing layer are formed.

[0059] Fig.30 It is a schematic diagram of the state of the connecting part after the first insulating layer and the second insulating layer are formed.

[0060] Description of reference numerals:

[0061] 1. Main body, 2. Connecting part, 21. Second circuit board layer group, 211. First substrate, 212. First wiring layer, 2121. Grounding structure, 2122. Grounding unit, 2123. First wiring part, 2124. First signal line, 2125. First sub-grounding line, 2126. Second sub-grounding line, 2127. Second wiring part, 213. Second wiring layer, 2131. Second signal line, 2132. Third sub-grounding line, 2133. Fourth sub-grounding line, 2134 , a third grounding portion, 2135, a fourth grounding portion, 22, a first circuit board layer group, 221, a second substrate, 222, a third routing layer, 23, a first insulating layer, 231, a first insulating portion, 232, an exposed area, 2321, an opening, 24, an electromagnetic shielding layer, 25, an adhesive layer, 26, a first conductive structure, 27, a second conductive structure, 28, a second insulating layer, 291, a first via hole, 292 a second via hole, 3, a first conductive layer, 4, a second conductive layer, 5, a third conductive layer. DETAILED DESCRIPTION

[0062] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0063] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0064] 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 an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0065] The present disclosure provides a flexible circuit board. Figures 1 to 22 As shown, 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 arranged on one side of the first substrate 211, the first routing layer 212 includes a plurality of grounding units 2122 arranged at intervals along the first direction, a first routing portion 2123 is arranged on one side of the plurality of grounding units 2122, and the first routing portion 2123 includes a first grounding wire; the first The insulating layer 23 is arranged on a 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 wire; the electromagnetic shielding layer 24 is arranged on a 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 wire.

[0066] The connection part 2 of the flexible circuit board includes a first wiring layer 212, a first insulating layer 23 and an electromagnetic shielding layer 24 which are stacked. The first wiring layer 212 includes a plurality of grounding units 2122. The first wiring layer 212 digs out the part between the grounding units 2122, which can reduce the thickness of the connection part 2 in this area and reduce the bending rebound force of the connection part 2. The first insulating layer 23 is provided with an exposed area 232, and 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. The electromagnetic shielding layer 24 is connected to the grounding unit 2122 through the exposed area 232, which can ensure the grounding effect of the electromagnetic shielding layer 24. Therefore, the flexible circuit board can take into account the bending performance of the connection part 2 while ensuring the grounding effect of the electromagnetic shielding layer 24 of the connection part 2.

[0067] The flexible circuit board involved in the embodiment of the present disclosure is described in detail below with reference to specific examples.

[0068] like Figure 1As shown, the flexible circuit board includes a main body 1 and a connecting part 2, one end of the connecting part 2 is connected to the edge of the main body 1, and the other end is connected to the main board of the display device, and the connecting part 2 extends along a first direction. Figure 2 and Figure 3 As shown, the connection part 2 includes a first circuit board layer group 22, the first circuit board layer group 22 includes a first substrate 211 and a first wiring layer 212, the first wiring layer 212 is arranged on one side of the first substrate 211, and the first wiring layer 212 includes a grounding structure 2121, and first wiring parts 2123 are arranged on both sides of the grounding structure 2121 along the second direction, and the first wiring parts 2123 are used to connect with the binding part of the display panel. The width W1 of the first wiring parts 2123 on both sides is the same, and the distance between the two first wiring parts 2123 and the multiple grounding units 2122 is equal, so as to avoid uneven force on the connection part 2 when bending, which causes peeling between layers.

[0069] It should be noted that the second direction is perpendicular to the first direction. Figure 3 The x direction is shown in Figure 3 The y direction is shown in FIG.

[0070] The first routing portion 2123 includes two first signal lines 2124, and a first grounding line is respectively provided on both sides of the two first signal lines 2124. The signals of the two first signal lines 2124 of the first routing portion 2123 are shielded by the first grounding lines to prevent the signals of the two first routing portions 2123 from interfering with each other. The two first grounding lines include a first sub-grounding line 2125 and a second sub-grounding line 2126. The first sub-grounding line 2125 is located between the plurality of grounding units 2122 and the first signal line 2124, and the second sub-grounding line 2126 is located between the first signal line 2124 and the edge of the first substrate 211.

[0071] The grounding structure 2121 may include a plurality of grounding units 2122 spaced apart along a first direction, two first sub-grounding lines 2125 spaced apart on both sides of the plurality of grounding units 2122, and the first routing layer 212 between two adjacent grounding units 2122 and between the grounding unit 2122 and the two first sub-grounding lines 2125 are hollowed out. Two first signal lines 2124 are sequentially arranged on one side of the first sub-grounding line 2125 away from the grounding unit 2122, and a second sub-grounding line 2126 is arranged outside the first signal line 2124 farthest from the plurality of grounding units 2122. The two first sub-grounding lines 2125 are equidistant from the plurality of grounding units 2122.

[0072] It can be understood that the grounding unit 2122 is an island structure in the first routing layer 212, and the portion of the first routing layer 212 located around each grounding unit 2122 is hollowed out. In order to facilitate the processing of the mask pattern, reduce the cost of patterning the first routing layer 212, and form the grounding unit 2122, in this embodiment, the shape of the grounding unit 2122 is set to a regular shape, such as a rectangle. Of course, the grounding unit 2122 can also be set to other shapes such as a circle, a pentagon, a triangle, etc., which are not listed here one by one. Furthermore, the grounding structure 2121 can also set the spacing between any adjacent grounding units 2122 to be equal.

[0073] The two first signal lines 2124, the first sub-grounding line 2125 and the second sub-grounding line 2126 all extend along the first direction. Along the first direction, the widths of various parts of the first signal line 2124 are equal, the widths of various parts of the first sub-grounding line 2125 are equal, and the widths of various parts of the second sub-grounding line 2126 are equal. The width of the first sub-grounding line 2125 and the width of the second sub-grounding line 2126 are greater than the width of the first signal line 2124, which can achieve a better grounding effect.

[0074] like Figure 4 As shown, the connection portion 2 further includes a first insulating layer 23, which is disposed on a side of the first wiring layer 212 away from the first substrate 211, and includes two first insulating portions 231, which respectively cover the first signal lines 2124 of the two first wiring portions 2123 and expose at least a portion of the grounding structure 2121. That is, the edge of the first insulating portion 231 may be located on the surface of the plurality of grounding units 2122, or may be located between the first signal line 2124 and the plurality of grounding units 2122.

[0075] like Figure 5 As shown, the edge of the first insulating portion 231 is located between the first signal line 2124 and the plurality of grounding units 2122. An exposed area 232 is formed between the edges of the two first insulating portions 231 close to the plurality of grounding units 2122. It can be understood that the exposed area 232 is in the shape of an open opening 2321. The exposed area 232 can pass through the bending area of ​​the connecting portion 2 along the first direction, or can pass through the entire connecting portion 2 along the first direction. 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.

[0076] An electromagnetic shielding layer 24 is provided on one 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 through the exposed area 232. The area of ​​the electromagnetic shielding layer 24 can be the same as the area of ​​the first substrate 211. As shown in the figure, in order to ensure the grounding effect of the electromagnetic shielding layer 24, the edges of the two first insulating parts 231 close to the multiple grounding units 2122 are respectively located between the gaps between the multiple grounding units 2122 and the two first sub-grounding lines 2125.

[0077] In this way, the electromagnetic shielding layer 24 covers the side of the grounding unit 2122 away from the first substrate 211 and the side of the grounding unit 2122, so that the electromagnetic shielding layer 24 is more tightly combined with the grounding unit 2122. It should be noted that the side of the grounding unit 2122 is vertically connected between the side of the grounding unit 2122 close to the first substrate 211 and the side of the grounding unit 2122 away from the first substrate 211.

[0078] The exposed area 232 is provided on the first insulating layer 23, and the plurality of grounding units 2122 are provided in the exposed area 232, so that the thickness of the connecting portion 2 in the area where the grounding structure 2121 is located can be reduced, and the space occupied by the area where the grounding structure 2121 is located in the display device is reduced. During the bending process of the connecting portion 2 of the flexible circuit board, the connecting portion 2 is more easily bent in the area with a smaller thickness, thereby reducing the bending rebound force of the connecting portion 2.

[0079] The first insulating layer 23 digs out the outer part 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 wiring parts 2123, the first wiring 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 part 2 in the outer area of ​​the grounding unit 2122, and reduce the rebound force of the bending connecting part 2 in the outer area of ​​the grounding unit 2122.

[0080] like Figure 2 , Figure 6 , Figure 7 As shown, in order to better achieve 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. Figure 6As shown, the first insulating portion 231 may 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, and the width of the exposed portion of the first sub-grounding line 2125 is d2. Figure 2 As shown, the first insulating portion 231 may also expose the second sub-grounding line 2126, and the electromagnetic shielding layer 24 is connected to the exposed portion of the second sub-grounding line 2126, and the width of the exposed portion of the second sub-grounding line 2126 is d1. Figure 7 As shown, the first insulating portion 231 may also expose the first sub-grounding line 2125 and the second sub-grounding line 2126 at the same time, and the electromagnetic shielding layer 24 is connected to both the exposed portion of the first sub-grounding line 2125 and the exposed portion of the second sub-grounding line 2126, so as to better ensure the grounding effect of the electromagnetic shielding layer 24. The width d2 of the exposed portion of the first sub-grounding line 2125 may be equal to the width d1 of the exposed portion of the second sub-grounding line 2126.

[0081] Figure 7 and Figure 8 As shown, the first insulating portion 231 may expose part of the first grounding line or the entire first grounding line. When the first insulating portion 231 exposes part of the first sub-grounding line 2125, the edges of the two first insulating portions 231 close to the multiple grounding units 2122 are located between the two sides of the first sub-grounding line 2125. When the first insulating portion 231 exposes the entire first sub-grounding line 2125, d2 is the width of the first sub-grounding line 2125, and the edges of the two first insulating portions 231 close to the multiple grounding units 2122 are located between the first sub-grounding line 2125 and the first signal line 2124. When the first insulating portion 231 exposes a portion 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.

[0082] Since the width of the first sub-grounding line 2125 and the second sub-grounding line 2126 is relatively small, there are process tolerances in the process of forming the first insulating layer 23. If the first sub-grounding line 2125 and the second sub-grounding line 2126 are directly exposed, the first signal line 2124 may be exposed, affecting signal transmission. The first insulating portion 231 exposes part of the first grounding line, and while ensuring the grounding effect of the electromagnetic shielding layer 24, the first insulating portion 231 can completely cover the first signal line 2124, without affecting signal transmission.

[0083] 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 leave a larger process tolerance range and reduce the process difficulty of forming the first insulating layer 23. However, since increasing the width of the first sub-grounding line 2125 will affect the wiring of the first signal line 2124, the width of the second sub-grounding line 2126 of the two first routing parts 2123 can be increased, so that the width of the second sub-grounding line 2126 is greater than the width of the first sub-grounding line 2125, the first insulating part 231 can expose the increased part of the second sub-grounding line 2126, and reserve grounding space for the electromagnetic shielding layer 24 on the second sub-grounding line 2126.

[0084] like Figures 9 to 12 As shown, Figures 2 to 5 The difference is that each grounding unit 2122 is respectively connected to the first sub-grounding wire 2125 on both sides, so that multiple grounding units 2122 and the first sub-grounding wire 2125 form a mesh structure, which increases the area of ​​the grounding structure 2121 and can achieve a better electromagnetic grounding effect. While the two first insulating parts 231 respectively cover the first sub-grounding wires 2125 of the two first routing parts 2123, the orthographic projection of the first insulating part 231 on the first substrate 211 overlaps with the orthographic projection of the multiple grounding units 2122 on the first substrate 211.

[0085] When the connection part 2 of the flexible circuit board may also have a single-sided signal routing, such as Figures 13 to 16 As shown. The grounding structure 2121 is the same as that in the figure, and includes a plurality of grounding units 2122 spaced apart along a first direction, and a first routing portion 2123 may be provided on one side of the grounding structure 2121. In order to prevent separation between layers when the connecting portion 2 is bent, a second routing portion 2127 may be provided on the other side of the grounding structure 2121, and the width of the first routing portion 2123 is equal to the width of the second routing portion 2127. The distance between the first routing portion 2123 and the plurality of grounding units 2122 and the distance between the second routing portion 2127 and the plurality of grounding units 2122 are equal.

[0086] The first wiring portion 2123 includes two first signal lines 2124 and two first grounding lines, the two first grounding lines include a first sub-grounding line 2125 and a second sub-grounding line 2126, the first sub-grounding line 2125 is located between the plurality of grounding units 2122 and the first signal line 2124, the second sub-grounding line 2126 is located between the first signal line 2124 and the edge of the first substrate 211, and the width of the second sub-grounding line 2126 is greater than the width of the first sub-grounding line 2125. The second wiring portion 2127 is a virtual grounding line and is not connected to the binding portion of the display panel.

[0087] The first insulating layer 23 includes a first insulating portion 231, which covers the first signal line 2124 and the first sub-grounding 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-grounding 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-grounding 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.

[0088] The orthographic projection of the second wiring 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, and the electromagnetic shielding layer 24 is connected to the exposed portion of the second sub-grounding line 2126, the plurality of grounding units 2122, and the virtual grounding line.

[0089] like Figures 17 to 20 As shown, Figures 9 to 12 The difference is that each grounding unit 2122 is connected to the second routing portion and the first sub-grounding line 2125 respectively, so that the multiple grounding units 2122, the first sub-grounding line 2125 and the second routing portion form a mesh structure, which increases the area of ​​the grounding structure 2121 and can achieve a better electromagnetic grounding effect. The edge of the first insulating portion 231 close to the multiple grounding units 2122 is located between the first sub-grounding line 2125 and the second routing portion 2127, and the orthographic projection of the first insulating portion 231 on the first substrate 211 overlaps with the orthographic projection of the multiple grounding units 2122 on the first substrate 211, that is, the orthographic projection of the grounding unit 2122 on the first substrate 211 is partially 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 on the side of the grounding unit 2122 away from the first substrate.

[0090] like Fig.21As shown, in other feasible embodiments, 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 opening 2321 on the first substrate 211. Specifically, the orthographic projection of the grounding unit 2122 on the first substrate 211 coincides with the orthographic projection of the opening 2321 on the first substrate 211. At least a portion of the second sub-grounding line 2126 is exposed at both sides of the first insulating layer 23 in the second direction.

[0091] The advantage of such a configuration is that the first insulating layer 23 is a whole layer, and there is no risk of the first signal line 2124 being exposed to the outside, and there is no need to consider process tolerances. In addition, 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 part 2 is located, thereby reducing the space occupied by the entire display device. In addition, although the first insulating layer 23 is provided between two adjacent grounding units 2122, the bending performance of the connecting part 2 is not affected while ensuring the grounding effect of the electromagnetic shielding layer 24. The thickness of the first routing layer 212 is usually smaller than that of the first insulating layer 23, so the bending performance of the connecting part 2 in this area can be reduced.

[0092] like Fig. 22 As shown, 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 arranged on the first substrate 211 and the side 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, and the second signal line 2131 is connected to the first signal line 2124 through the first conductive structure 26 in the first via 291. The second signal line 2131 forms a parallel structure with the first signal line 2124 to reduce the resistance during signal transmission. The second signal line 2131 can be set to two, and the two second signal lines 2131 are respectively connected through the first conductive structures 26 in the two first vias 291.

[0093] Second grounding wires may be provided on both sides of the second signal line 2131, and the second grounding wire may include a third sub-grounding wire 2132 and a fourth sub-grounding wire 2133. The third sub-grounding wire 2132 is located on the side of the second signal line 2131 close to the grounding structure 2121, and the fourth sub-grounding wire 2133 is located on the side of the second signal line 2131 away from the grounding structure 2121, so as to shield the signal loaded on 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 are loaded with the same signal.

[0094] The second signal line 2131, the third sub-grounding line 2132 and the fourth sub-grounding line 2133 constitute a third grounding portion 2134. In order to ensure that the bending rebound force provided by the second routing layer 213 on both sides of the grounding structure 2121 is equal, a fourth grounding portion 2135 is set on the other side of the grounding structure 2121, and the width of the fourth grounding portion 2135 can be set equal to that of the third grounding portion 2134.

[0095] like Fig.30 As shown, for the wearable display module, the flexible circuit board also includes a second circuit board layer group 21, the second circuit board layer group 21 is arranged on the side of the first circuit board layer group 22 close to the second wiring layer 213, the second circuit board layer group 21 includes a second substrate 221 and a third wiring layer 222, the third wiring layer 222 is connected to the second wiring layer 213 through an adhesive layer 25, and the third wiring layer 222 is arranged in most areas of the side of the second substrate 221 away from the second wiring layer 213 to shield signal interference. The third wiring layer 222 is connected to the second wiring layer 213 through the second conductive structure 27 in the second via hole, and the second via hole passes through the third wiring layer 222, the second substrate 221, the adhesive layer 25 and the second wiring layer 213. In addition, the flexible circuit board may also include a second insulating layer 28, and the second insulating layer 28 is arranged on the side of the third wiring layer 222 away from the second substrate 221.

[0096] At present, when forming the first via hole 291, the first conductive layer 292 and the second via hole 3 are formed on the surface of the first wiring layer 212, and when forming the second via hole, the second conductive layer 4 is also formed on the surface of the third wiring layer 222. The existence of the first conductive layer 292 and the second via hole 3 and the second conductive layer 4 will increase the thickness of the flexible circuit board, increase the thickness of the display module, and squeeze the space in the display device. As shown in the figure, the first conductive structure 26 is formed in the first via hole 291, and the second conductive structure 27 is formed in the second via hole, eliminating the first conductive layer 292 and the second via hole 3 and the second conductive layer 4, thereby reducing the thickness of the flexible circuit board.

[0097] The following is an explanation of the manufacturing process of the flexible circuit board involved in the embodiment of the present disclosure. Fig.23 As shown, the manufacturing process of the flexible circuit board may include:

[0098] Step S10, forming a second via hole in the first conductive layer 292 on opposite sides of the first substrate 211; 3 and a second conductive layer 4, such as Fig.24 shown.

[0099] Step S20, patterning the second conductive layer 4 to form a second wiring layer 213, such as Fig.25 shown.

[0100] Step S30, using the adhesive layer 25 to bond the second substrate 221 of the second circuit board layer group 21 and the second wiring layer 213 together. Fig.26 shown.

[0101] Step S40, making a first via hole 291 through the first conductive layer 292 and a second via hole; 3 and the first substrate 211, and making a second via hole through the third wiring layer 222, the second substrate 221, the adhesive layer 25 and the second wiring layer 213, such as Fig. 27 shown.

[0102] Step S50, filling the first conductive structure 26 in the first via hole 291, and filling the second conductive structure 27 in the second via hole, such as Fig.28 shown.

[0103] Step S60, patterning the first conductive layer 292 and the second via hole 3 to form the first wiring layer 212, and patterning the third conductive layer 5 to form the third wiring layer 222, such as Fig.29 shown.

[0104] Step S70: attaching the first insulating layer 23 to the surface of the first wiring layer 212, and attaching the second insulating layer 28 to the surface of the third wiring layer 222. Fig.30 shown.

[0105] The embodiment of the present disclosure also provides a display module. The display module may include a display panel involved in any one of the above embodiments of the present disclosure, the main body 1 of the flexible circuit board is usually attached to the non-display surface of the display panel, and the connecting part 2 is bent from the side of the display panel to the display surface of the display panel and is bound to the display panel.

[0106] The embodiment of the present disclosure also provides a display device. The display device may include the display module involved in the embodiment of the present disclosure. The specific structure and beneficial effects of the display module have been described in detail above, so they will not be repeated here.

[0107] It should be noted that, in addition to the display module, the display device also includes other necessary parts and components, such as a housing, a power cord, etc. Those skilled in the art may make corresponding supplements according to the specific use requirements of the display device, which will not be elaborated here.

[0108] 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 it can be an emerging wearable device, such as a virtual reality device and an augmented reality device, which are not listed here one by one.

[0109] 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 modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A flexible circuit board, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: A flexible circuit board comprising any one of claims 1 to 19.

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

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