WO2021082287A1

WO2021082287A1 - Support structure and flexible printed circuit board

Info

Publication number: WO2021082287A1
Application number: PCT/CN2020/072304
Authority: WO
Inventors: 吴华丽
Original assignee: 南昌欧菲生物识别技术有限公司
Priority date: 2019-10-30
Filing date: 2020-01-15
Publication date: 2021-05-06

Abstract

The present application relates to an electronic device and a camera module therefor. The camera module comprises a lens as well as a photosensitive element and a reflective prism provided on opposite sides of the lens, and also comprises a first direction anti-shake structure and a second direction anti-shake structure respectively configured to drive the photosensitive element to rotate about a first axis and to drive the photosensitive element to translate along a second axis perpendicular to the first axis, as well as a third direction anti-shake structure configured to drive the reflective prism to rotate around a rotating shaft parallel to the second axis, the axis of the rotating shaft being parallel to the light incident surface.

Description

Support structure and flexible printed circuit board

Technical field

The invention relates to the technical field of flexible printed circuit boards, not only to a supporting structure for flexible printed circuit boards, but also to a flexible printed circuit board with such supporting structure.

Background technique

At present, the development of electronic devices such as mobile phones tends to achieve ultra-thinness, requiring the cameras to become thinner and thinner, and in turn, the FPC (ie flexible printed circuit board) is required to be thinner and thinner. However, the insufficient rigidity of the FPC caused by the thinness of the FPC can easily cause the sensor mounted on the FPC to crack and the module to fail. Therefore, there is an urgent need for an FPC with a smaller thickness but still ensuring rigidity and not easy to break.

Summary of the invention

According to various embodiments of the present application, a supporting structure is provided.

A supporting structure includes a flexible structure layer, the flexible structure layer has a first surface on which a concave-convex texture is formed, and the concave-convex texture has grooves that partially interrupt the concave-convex texture.

A flexible printed circuit board, comprising a circuit board body, the circuit board body has a first outer side and a second outer side facing away from each other, wherein the first outer side and/or the second outer side are fixed with the aforementioned The support structure described in any one of the embodiments.

The details of one or more embodiments of the present application are set forth in the following drawings and description. Other features, purposes and advantages of this application will become apparent from the description, drawings and claims.

Description of the drawings

In order to better describe and explain the embodiments or examples of those inventions disclosed herein, one or more drawings may be referred to. The additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed inventions, the currently described embodiments or examples, and the best mode of these inventions currently understood.

Figure 1 is a schematic diagram of the stress direction when a traditional flexible printed circuit board is bent under a force;

FIG. 2 is a schematic diagram of the stress direction when a traditional flexible printed circuit board with a supporting structure is bent under a force;

3 is a schematic structural diagram of a flexible printed circuit board with a supporting structure according to the first embodiment of the present invention;

4 is a schematic top view of the first structure of the flexible structure layer according to the first embodiment of the present invention;

Figure 5 is an enlarged view of part X in Figure 4;

6 is a schematic cross-sectional view of the first structure of the flexible structure layer according to the first embodiment of the present invention;

7 is a schematic cross-sectional view of the second structure of the flexible structure layer in the first embodiment of the present invention;

8 is a schematic cross-sectional view of another structure of the supporting structure in Embodiment 1 of the present invention;

9 is a schematic structural diagram of a flexible printed circuit board according to the second embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a flexible printed circuit board according to the third embodiment of the present invention.

Detailed ways

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, many specific details are explained in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or a central element may also be present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or an intermediate element may be present at the same time.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and/or" as used herein includes any and all combinations of one or more related listed items.

In the art, a traditional printed circuit board is shown as a flexible printed circuit board 1 in FIG. 1, wherein the flexible printed circuit board 1 is a traditional printed circuit board, and includes an insulating board and a printed circuit. The thickness range of traditional printed circuit boards is 0.072mm-0.122mm. In the process of implementing this traditional technology, the inventor found that when the flexible printed circuit board 1 is bent under force, the direction of the stress F1 is shown by the arrow in the figure. Because the FPC itself has the characteristics of lightness and thinness, the mechanical strength is low, and the flexible printed circuit The board 1 is easily broken.

In view of the defects of the flexible printed circuit board 1, improvements have been proposed in the art, as shown in the flexible printed circuit board 2 of FIG. 2. The flexible printed circuit board 2 includes a flexible printed circuit board body 21 and a supporting structure 22 provided on one surface of the flexible printed circuit board body 21, wherein the supporting structure 22 and the flexible printed circuit board body 21 are connected by an adhesive layer 23.

In the process of implementing the flexible printed circuit board 2, the inventor found that this solution, although to a certain extent, can serve the purpose of strengthening the flexible printed circuit board body 21. However, when the flexible printed circuit board 2 is forced to bend, the stress F2 is concentrated in the vertical direction of the line connecting the flexible printed circuit board body 21 and the supporting structure 22, that is, the edge of the flexible printed circuit board body 21 and the supporting structure 22 corresponding to each other. A phenomenon of stress concentration may occur, which causes the flexible printed circuit board to be easily broken along the corresponding edges of the flexible printed circuit board body 21 and the supporting structure 22. In addition, due to the need to rely on the support structure 22 to increase the strength, if the thickness of the support structure 22 is too small, it is difficult to meet the requirements. If the thickness of the support structure 22 is large, the thickness of the flexible printed circuit board 2 will be large, which can no longer meet the requirements. Thin and light requirements.

In view of the above-mentioned problems, the embodiment of the present invention improves the support structure. Please refer to FIG. 3, the first embodiment of the present invention provides a flexible printed circuit board 100, which includes a circuit board body 10 and a supporting structure 20 fixed to the circuit board body 10. Wherein, the circuit board body 10 has a first outer side surface 110 and a second outer side surface 120 disposed away from each other. The supporting structure 20 is disposed on the second outer side surface 120. The wire layer of the circuit board body 10 is printed on the first outer side surface 110.

Please refer to FIG. 3, the support structure 20 includes a flexible structure layer 210 attached to the second outer surface 120 of the circuit board body 10. The flexible structure layer 210 has a first surface 212 facing the circuit board body 10 and a second surface 214 facing away from the circuit board body 10. 4 to 7 together, in the present embodiment of the present invention, a concave-convex texture 220 is formed on the first surface 212, so that the stress is dispersed along the concave-convex texture 220, thereby reducing stress concentration; and the concave-convex texture 220 is formed in the concave-convex texture 220. The groove 230 where the texture 220 is partially interrupted, and the groove 230 increases the force-bearing area of the uneven texture 220 and better eliminates stress concentration. Therefore, the stress concentration generated at the edges of the circuit board body 10 and the supporting structure 20 is significantly reduced, and the flexible printed circuit board 100 is not easily broken along the edges of the circuit board body 10 and the supporting structure 20.

According to the reliability test, the bending resistance of the flexible printed circuit board 100 of this embodiment is higher than that of the traditional flexible printed circuit board 1. If the overall thickness of the flexible printed circuit board 100 is the same as that of the conventional flexible printed circuit board 1, the flexible printed circuit board 100 of this embodiment also has better rigidity.

The following describes the arrangement of the concave-convex texture 220 and the groove 230 in combination with two specific structures.

Please refer to FIG. 4 to FIG. 6. In one arrangement, the uneven texture 220 is specifically a grid structure, and the grid structure includes a plurality of grids. The grid includes a plurality of meshes 222 surrounded by grid lines 221. In the concave-convex texture 220, the mesh 222 is concave relative to the plane where the grid line 221 is located, and the grid line 221 is a convex solid part, that is to say, the grid line 221 is the convex of the concave-convex texture 220 in this setting. Part, the mesh 222 corresponds to the recessed part. The groove 230 is provided on the grid lines 221 surrounding the mesh 222. Please refer to FIG. 5, which is a schematic cross-sectional view along the length of the grid line 221. Please refer to FIG. 6, which is a schematic cross-sectional view along the width direction of the grid line 221. Due to the grid structure, when the flexible printed circuit board 100 is bent, the stress F can be dispersed along the grid lines 221, thereby reducing stress concentration. According to needs, grooves 230 can be provided on each grid line, so as to increase the force-bearing area of the uneven texture 220 as much as possible, and better eliminate stress concentration. In addition, if the length of the grid line allows, at least two grooves 230 can be provided on a single grid line, so as to increase the force-bearing area of the uneven texture 220 as much as possible, and better eliminate stress concentration.

There are many ways to form the grid structure. In a specific solution, the grid structure is a continuous grid area covering the first surface 212. In other words, all areas of the first surface are provided with grid areas. In this way, no matter where the flexible printed circuit board is bent, the stress can be dispersed in multiple directions along the continuously arranged grid, which can have a better effect of eliminating stress concentration, and the flexible printed circuit board 100 is not easy to follow the circuit. The edge of the board body 10 corresponding to the supporting structure 20 is broken off. In another specific solution, the grid structure may also include multiple grid areas, evenly dispersed on the first surface 212, so that when the flexible circuit board is bent under force, multiple grid areas participate in the dispersion. The stress prevents the flexible printed circuit board 100 from being broken along the corresponding edges of the circuit board body 10 and the supporting structure 20. The groove 230 partially interrupts the grid lines. As a specific solution, in this embodiment, the dimension of the grid structure along the direction perpendicular to the first surface 212 is defined as the thickness. Please refer to FIG. The dimension perpendicular to the first surface 212 is defined as the depth, and the depth of the groove 230 is set to be smaller than the thickness of the grid structure, that is, smaller than the thickness of the grid line 221. After the groove 230 is arranged in this way, a breakpoint is formed on the grid line 221 but not broken, ensuring that the stress F can still be dispersed along the grid line 221; at the same time, the groove 230 increases the force-bearing area of the texture structure 220 and better eliminates it Stress concentration.

In one embodiment, the depth of the groove 230 is set to be less than or equal to 1/2 of the thickness of the grid line 221, so as to increase the force-bearing area of the uneven texture 220 as much as possible and ensure the strength of the grid line. The thickness of the grid line 221 is generally limited. If the depth of the groove 230 is set to be less than or equal to 1/2 of the thickness of the grid line 221, the grid line still retains more than half of the thickness to ensure the strength.

In order to increase the force-bearing area of the uneven texture 220 as much as possible, please refer to FIG. 4 in conjunction with FIG. 5. The dimension of the groove 230 along the axis B of the grid line 221 is the same as the dimension of the grid line 221 along its axis B. The size of the direction is the same. More specifically, the mesh is a polygon, such as a regular polygon. Along the direction of the axis of the grid line 221, the size of the grid line 221 is consistent with the size of the groove 230. With this arrangement, the groove 230 connects two adjacent mesh holes 222, and the area of the inner wall of the groove 230 increases, increasing The force-receiving area of the uneven texture 220. On the other hand, the size of the grid line 221 along the axis B is generally very narrow, and the size of the groove 230 is set to be consistent with the size of the grid line, and it is easier to form the groove 230 on the grid line. In this embodiment, the grid line 221 constitutes the side length of the polygon in its length direction, the thickness of the grid line 221 is the dimension perpendicular to the first surface 212, and the dimension of the grid line 221 in the direction along its axis B It is defined as the width of the grid line, so the width of the grid is the dimension of the grid line 221 perpendicular to its length direction and thickness direction. The axis B is the center line of the grid line 221 in its length direction, and the grid lines 221 on both sides of the axis B are symmetrical about the axis B.

In the above embodiment, the structure of the groove 230 is not limited, as long as the force-receiving area of the uneven texture is increased. Referring to FIG. 6, the surface of the grid line 221 of the opening of the groove 230 includes the groove bottom 231 and the side wall 232. The sum of the area of the groove bottom 231 and the side wall 232 is larger than the opening area of the groove 230, so the overall increase is still The force-bearing area of the uneven texture 220 is enlarged, and the stress concentration is better eliminated.

In a specific solution, in the direction perpendicular to the first surface 212, the cross section of the groove 230 is rectangular, that is, it may be a rectangular groove as shown in FIG. Connected. In addition, the shape of the groove 230 is not limited to a rectangular groove. For example, in the direction perpendicular to the first surface 212, the cross section of the groove 230 may also be trapezoidal or irregular.

In FIG. 5, the groove 230 communicates with the meshes on both sides, but the groove 230 may also be a groove connected with the mesh on one side only, and the groove 230 forms a gap on one side edge of the grid line.

Please refer to FIG. 7, in another arrangement, the concave-convex texture 220 is specifically a patterned structure. The biting structure includes a plurality of biting substructures 201 connected to each other. When the flexible printed circuit board 100 is bent, the stress can be dispersed along the nipple structure 201, thereby reducing stress concentration.

A groove 230 is provided in the biting substructure 201. The groove 230 forms a breaking point on the flower sub-structure 201 but does not break the flower sub-structure 201, ensuring that the stress can still be dispersed along the flower sub-structure 20; at the same time, the groove 230 increases the force-bearing area of the flower sub-structure 201, and more Eliminate stress concentration well. The structure and shape of the bite structure 201 are not limited, and can be any regular or irregular shape. The embossing structure can be formed by processing the surface of the flexible structure layer 20 with a embossing mold. The embossing process itself is relatively mature, and it is only necessary to add a corresponding structure of the forming groove 230 on the mold.

The position of the groove 230 on the biting substructure 201 is flexible. For example, referring to FIG. 7, as a specific solution, the groove 230 is disposed on the embossing substructure 201 at a position close to the edge of the embossing substructure 201, and the depth of the groove 230 is less than the thickness of the embossing substructure 201 at this position, so the groove 230 increases the force-receiving area of the bite substructure 201, so that a breakpoint is formed on the bite substructure 201, but the bite substructure 201 is not broken.

For another example, the groove 230 is disposed at the middle position of the biting substructure 201, and the depth of the groove 230 is less than the thickness of the biting substructure 201 at this position to ensure the strength of the biting substructure 201. For another example, the groove 230 is disposed at a position close to the adjacent flower biting substructure 201, the depth of the groove 230 is less than the thickness of the flower biting substructure 201 at this position, and the grooves 230 on the adjacent flower biting substructure 201 are connected to each other In this way, the size of the groove 230 is relatively large, which is convenient for manufacturing.

Similar to the uneven texture 220 having a grid structure, in this embodiment, the shape of the groove 230 is not particularly limited. The purpose of the groove 230 is to make the biting sub-structure 201 form a break point, so as long as this purpose is met, the groove 230 of any shape and structure can be used.

Further, in this embodiment, referring to FIG. 8, the support structure 20 further includes a rigid structure layer 240 attached to the flexible structure layer 210, and the rigid structure layer 240 is attached to the second surface 214 of the flexible structure layer 210. On the basis of the flexible structure layer 210, a rigid structure layer is further added to prevent the flexible printed circuit board from being broken easily due to insufficient rigidity. Therefore, the support structure 20 adopts a double-layer structure, which can further improve the hardness of the support structure 20 on the one hand, and can also improve the bending resistance of the support structure 20 on the other hand.

The flexible structure layer 210 is made of a flexible material with relatively good bending ability, and mainly plays a role of dispersing stress. For example, the flexible structure layer 210 is a polymer layer made of easily available polymers. The specific material of the polymer layer includes but is not limited to polyimide (PI for short).

The rigid structure layer 240 has greater hardness and bending resistance than the flexible structure layer. The rigid structure layer 240 may be PPG (Prepreg) made of insulating resin such as epoxy resin. The prepreg material PPG has adhesive ability, and the prepreg material PPG is used as the material of the rigid structure layer 240. When forming the support structure 20, the prepreg material PPG and the flexible structure layer 210 can be laminated to combine the two together; After the Prepreg is laminated, the semi-cured epoxy resin is squeezed away, starts to flow and solidify, bond the flexible structural layers 210 together, and form a reliable insulator. In this process, there is no need to use an adhesive layer to bond the flexible structure layer 210 and the rigid structure layer 240, which simplifies the process steps.

The rigid structure layer 240 may also be a build-up film such as ABF (Ajinomoto Build-up Film) including insulating resin such as epoxy resin. The rigid structure layer 240 may also be a photosensitive insulating layer including a photosensitive electrically insulating resin.

In this embodiment, the first surface 212 of the flexible structure layer 210 of the support structure 20 is attached to the second outer surface 120 of the circuit board body 10. As a specific solution, please refer to FIG. 3, the flexible structure layer 210 and the second outer side 120 of the circuit board body 10 are bonded and fixed by an adhesive layer 30. The flexible structure layer 210 is bonded to the circuit board body 10. When the circuit board body 10 is bent, the stress is dispersed by the support structure 20, and the stress concentration generated at the edge of the circuit board body 10 and the support structure 20 is significantly reduced. The circuit board 100 is not easy to be broken along the corresponding edges of the circuit board body 10 and the supporting structure 20.

In another solution, the supporting structure 20 and the second outer side 120 of the circuit board body 10 are nested together. For example, a mounting groove for accommodating the supporting structure 20 is provided on the circuit board body 10. The supporting structure 20 is embedded in the installation groove. In another solution, the supporting structure 20 may also be formed on the circuit board body 10 by injection molding, that is, the two are formed as an integral piece by injection molding.

Please refer to FIG. 9, which is different from the first embodiment described above. In the second embodiment, the supporting structure 20 is disposed on the first outer side surface 110 of the circuit board body 10, while the second outer side surface 120 of the circuit board body 10 is not Set up support structure. In other words, the supporting structure 20 is provided on the surface of the circuit board body 10 with the printed circuit. The supporting structure 20 is bonded and fixed to the circuit board body 10 through the adhesive layer 30.

The structure of the supporting structure 20 is the same as that of the first embodiment. It may include only the flexible structure layer 210 as shown in FIG. 3, or it may include both the flexible structure layer 210 and the rigid structure layer 240 as shown in FIG. 8.

In the above first and second embodiments, when the support structure 20 only includes the flexible structure layer 210, the minimum thickness of the circuit board body 10 is only 0.036 mm, the minimum thickness of the flexible structure layer 210 can be only 0.0125 mm, and the adhesive layer 30 The thickness is 0.015mm. Thus, the overall thickness of the flexible printed circuit board 100 is 0.0635 mm, which is smaller than the thickness of the conventional flexible printed circuit board of 0.072-0.122 mm. However, after reliability testing, the flexible printed circuit board 100 of this embodiment has a higher bending resistance than the conventional one. Flexible printed circuit board 1. Further, if the overall thickness of the flexible printed circuit board 100 is consistent with the thickness of the conventional flexible printed circuit board 1, the flexible printed circuit board 100 of this embodiment has better rigidity.

Similarly, when the support structure 20 includes a flexible structure layer 210 and a rigid structure layer 240, the total thickness of the support structure 20 is 0.025 mm, the minimum thickness of the circuit board body 10 is only 0.036 mm, and the thickness of the adhesive layer 30 is 0.015 mm. In this way, the overall thickness of the flexible printed circuit board 100 is 0.076 mm, which is consistent with the minimum thickness of the traditional flexible printed circuit board 1, but its bending resistance is higher than that of the traditional flexible printed circuit board 1.

Please refer to FIG. 10. Based on the first embodiment, the present invention also provides a third embodiment. Wherein, a supporting structure 20 is also provided on the first outer side surface 110 of the circuit board body 10. That is, both the first outer side 110 and the second outer side 120 of the circuit board body 10 are provided with the supporting structure 20. The support structure 20 on each side of the circuit board body 10 may include only the flexible structure layer 210 as shown in FIG. 3, or may include both the flexible structure layer 210 and the rigid structure layer 240 as shown in FIG. 8. The supporting structure 20 on each side of the circuit board body 10 is respectively bonded to the circuit board body 10 through an adhesive layer 30.

In the third embodiment, the minimum thickness of the circuit board body 10 is only 0.036 mm, and the thickness of the adhesive layer 30 is 0.015 mm. When the supporting structure 20 only includes the flexible structure layer 210, the total thickness of the supporting structures on both sides is 0.025 mm, and the overall thickness of the flexible printed circuit board 100 is 0.091 mm, which is equivalent to the thickness of a traditional flexible circuit board, but has better rigidity.

When the support structure 20 includes a flexible structure layer 210 and a rigid structure layer 240, the total thickness of the support structure 20 on both sides is 0.050 mm, and the overall thickness of the flexible printed circuit board 100 is 0.116 mm, which is still the thickness of the traditional flexible circuit board 1. Within the thickness range, but the rigidity is improved.

It can be seen from the above comparison that the flexible printed circuit boards of the first to third embodiments are provided with the support structure 20, and the thickness of the circuit board body 10 can be reduced on the premise of achieving the same bending resistance, and the flexible printed circuit board The overall thickness of 100 is smaller than that of the conventional flexible printed circuit board 1, which satisfies the requirement of having a smaller thickness but still ensuring rigidity and not being easy to break. When the thickness is the same as the thickness 1 of the conventional flexible printed circuit board, the rigidity of the flexible circuit board of the three embodiments is better.

The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

The above-mentioned embodiments only express several embodiments of the present invention, and the descriptions are relatively specific and detailed, but they should not be understood as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

A support structure, characterized by comprising: a flexible structure layer, the flexible structure layer has a first surface, the first surface is formed with an uneven texture, and the uneven texture is partially interrupted by the uneven texture.的槽。 The groove.
The support structure according to claim 1, wherein the concave-convex texture is a grid structure, the grid structure includes a plurality of grids, and the grids include grid lines and a grid surrounded by grid lines. Mesh, the grooves are arranged on the grid lines of the grid structure.
The support structure according to claim 2, wherein the grid structure forms a continuous grid area covering the first surface on the first surface; or, the grid structure includes a plurality of grids. Grid area.
The support structure according to claim 3, wherein the plurality of grid areas are evenly dispersed on the first surface.
The supporting structure according to claim 2, wherein each of the grid lines is provided with the groove; or, the same grid line is provided with at least two of the recesses groove.
The support structure according to claim 2, wherein the grid is polygonal, and along the axis of the grid line, the size of the groove is consistent with the size of the grid line.
The support structure according to claim 2, wherein the groove is open on the surface of the grid line, the groove includes a groove bottom and a side wall, and the sum of the area of the groove bottom and the side wall Larger than the area of the opening of the groove.
The support structure according to claim 2, wherein the groove is connected or not connected with the adjacent mesh.
8. The supporting structure according to claim 8, wherein in a direction perpendicular to the first surface, the cross section of the groove is rectangular, trapezoidal or irregular.
The support structure according to any one of claims 1-9, wherein, in a direction perpendicular to the first surface, the size of the groove is less than or equal to 1/2 of the size of the grid structure.
The supporting structure according to claim 1, wherein the concave-convex texture is a biting structure, the biting structure includes a plurality of interconnected biting substructures, and the grooves are provided in the biting substructure .
The support structure according to claim 11, wherein the groove is arranged on the embossing substructure close to the edge of the embossing substructure, and the depth of the groove is smaller than the thickness of the groove where the embossing substructure is provided.
The support structure according to claim 11, wherein the groove is arranged in the middle position of the embossing substructure, and the depth of the groove is smaller than the thickness of the groove where the embossing substructure is provided.
The support structure according to claim 11, wherein the grooves on adjacent bite substructures communicate with each other.
The support structure according to claim 1, wherein the flexible structure layer has a second surface facing away from the first surface, and the support structure further comprises a rigid structure layer connected to the second surface.
The support structure according to claim 15, wherein the flexible structure layer is a polymer layer, and the material of the rigid structure layer is an insulating resin prepreg material.
A flexible printed circuit board, which is characterized by comprising a circuit board body, the circuit board body has a first outer side and a second outer side facing away from each other, wherein the first outer side and/or the second outer side The support structure according to any one of claims 1-16 is fixed on the side.
18. The flexible printed circuit board according to claim 17, wherein the circuit board body and the supporting structure are bonded and fixed by an adhesive layer.
The flexible printed circuit board according to claim 17, wherein the circuit board body is provided with a mounting groove, and the supporting structure is embedded in the mounting groove; or the circuit board body and the supporting structure Formed as a whole by injection molding.