Circuit board structure and method of manufacturing the same

Abstract

The application discloses a circuit board structure and a manufacturing method thereof. The circuit board structure comprises a circuit board, the circuit board comprises a first non-bending area, a first bending area, a second non-bending area, a second bending area and a third non-bending area which are sequentially connected along the length direction of the circuit board, and the first bending area is crossly arranged relative to the second bending area.

Description

Technical Field

[0001] This application relates to the field of circuit board technology, and in particular to a circuit board structure and its manufacturing method. Background Technology

[0002] In foldable electronic devices, such as foldable screen phones, the circuit boards need to withstand a higher number of folds to extend their lifespan. Currently, when existing circuit boards are folded, the bending radius at the folding point is small, resulting in greater bending stress and making the boards more prone to internal fatigue, thus affecting their lifespan. Summary of the Invention

[0003] In view of this, it is necessary to provide a circuit board structure and its manufacturing method that can solve the above problems.

[0004] The first aspect of this application provides a circuit board structure, including a circuit board, the circuit board including a first non-bending area, a first bending area, a second non-bending area, a second bending area and a third non-bending area connected sequentially along the length direction of the circuit board, the first bending area being arranged opposite to the second bending area.

[0005] In some embodiments, along the width direction of the circuit board, the second non-bending area includes a bent portion and a first planar portion and a second planar portion located on opposite sides of the bent portion; along the length direction of the circuit board, the first bending area is located between the first non-bending area and the first planar portion, and the second bending area is located between the second planar portion and the third non-bending area; the first planar portion is connected to the first bending area and separated from the third non-bending area, and the second planar portion is connected to the second bending area and separated from the first non-bending area.

[0006] In some embodiments, a first through groove is formed between the first non-bending area, the first bending area and the bending portion, and a second through groove is formed between the second bending area, the third non-bending area and the bending portion.

[0007] In some embodiments, the bent portion includes a first connecting portion and a second connecting portion, a first flat portion extending from the side of the first connecting portion, a second flat portion extending from the side of the second connecting portion, and an included angle between the first connecting portion and the second connecting portion of 60° to 120°.

[0008] In some embodiments, the circuit board structure includes a first reinforcing plate, a second reinforcing plate, and a third reinforcing plate, wherein the first reinforcing plate covers a portion of a first non-bending area, the second reinforcing plate covers a second non-bending area, and the third reinforcing plate covers a portion of a third non-bending area.

[0009] In some embodiments, the first bending region includes a first edge portion connected to the first bending region, the third non-bending region includes a first edge portion connected to the second bending region, the first reinforcing plate covers the first edge portion of the first bending region, and the third reinforcing plate covers the first edge portion of the third non-bending region.

[0010] In some implementations, the shape of the second reinforcing plate is adapted to the shape of the second non-bending region.

[0011] In some embodiments, the circuit board includes a first circuit board, an adhesive layer, and a second circuit board. The second circuit board is laminated to at least one side of the first circuit board through the adhesive layer. The adhesive layer has a first opening and a second opening. The first opening exposes a portion of the first circuit board and a portion of the second circuit board, and the second opening exposes a portion of the first circuit board and a portion of the second circuit board. The first opening is located in a first bending region, and the second opening is located in a second bending region.

[0012] The second aspect of this application provides a method for manufacturing any of the above-mentioned circuit board structures, comprising: bonding a second circuit board to one side of a first circuit board by an adhesive layer to obtain a laminated structure; processing the laminated structure to form a first non-bending area, a first bending area, a second non-bending area, a second bending area, and a third non-bending area connected sequentially along the length direction of the circuit board; and processing the second non-bending area so that the first bending area is intersected relative to the second bending area.

[0013] In some embodiments, the method of manufacturing the circuit board structure further includes installing a plurality of reinforcing plates on the side of the second circuit board away from the first circuit board.

[0014] In the circuit board structure and manufacturing method provided in this application, the first bending area and the second bending area are disposed on both sides of the second non-bending area, and the first bending area is intersected with the second bending area. When the first bending area and / or the second bending area are bent, the second non-bending area plays a constraining role on the bending deformation of the first bending area and the second bending area, so that the first bending area and the second bending area maintain a large bending radius when bent, reduce bending stress, and improve service life. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a circuit board structure provided in one embodiment of this application, viewed along the thickness direction.

[0016] Figure 2 This is a schematic diagram of a circuit board structure provided in one embodiment of this application, viewed along the width direction.

[0017] Figure 3 for Figure 1 A schematic diagram of the cross-section along AA.

[0018] Figure 4for Figure 1 A schematic diagram of the cross-section along BB.

[0019] Figure 5 for Figure 1 A schematic diagram of the cross-section along CC. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0022] Please see Figure 1 and Figure 2 This application provides a circuit board structure 100, including a circuit board 10. Viewed along the thickness direction Z of the circuit board 10, the circuit board 10 includes a first non-bending region 11, a first bending region 12, a second non-bending region 13, a second bending region 14, and a third non-bending region 15, sequentially connected along the length direction X of the circuit board 10. The first non-bending region 11, the second non-bending region 13, and the third non-bending region 15 are less prone to bending during folding, while the first bending region 12 and the second bending region 14 are more prone to bending during folding. In this application, the thickness direction Z is the stacking direction of each layer structure (such as a dielectric layer and a circuit layer) in the circuit board 10, the length direction X is the extension direction of the edge perpendicular to the bending position when the circuit board 10 is bent, and the width direction Y is the extension direction of the edge parallel to the bending position when the circuit board 10 is bent. The thickness direction Z, the length direction X, and the width direction Y are all perpendicular to each other.

[0023] The first bending zone 12 is intersecting the second bending zone 14. Viewed along the width direction Y, the projections of the first bending zone 12 and the second bending zone 14 intersect. When the first bending zone 12 and / or the second bending zone 14 are bent, the second non-bending zone 13 constrains the bending deformation of the first bending zone 12 and the second bending zone 14, ensuring a larger bending radius, reducing bending stress, and improving service life.

[0024] Along the width direction Y of the circuit board 10, the second non-bending region 13 includes a bent portion 131 and a first flat portion 132 and a second flat portion 133 located on opposite sides of the bent portion 131. The first flat portion 132 and the second flat portion 133 extend from opposite sides of the bent portion 131, respectively. Along the length direction X, the first bending region 12 is located between the first non-bending region 11 and the first flat portion 132, and the second bending region 14 is located between the second flat portion 133 and the third non-bending region 15. The first flat portion 132 is connected to the first bending region 12 and separated from the third non-bending region 15, and the second flat portion 133 is connected to the second bending region 14 and separated from the first non-bending region 11. The bent portion 131 is separated from the first non-bending region 11, the first bending region 12, the second bending region 14, and the third non-bending region 15, allowing the first bending region 12 and the second bending region 14 to be bent freely.

[0025] In some embodiments, a first through groove 101 is formed between the first non-bending area 11, the first bending area 12 and the bending portion 131, and a second through groove 102 is formed between the second bending area 14, the third non-bending area 15 and the bending portion 131, so as to improve the degree of freedom of bending of the first bending area 12 and the second bending area 14.

[0026] In some embodiments, any one of the first non-bending region 11, the first bending region 12, the second bending region 14, and the third non-bending region 15 is in contact with the bending portion 131.

[0027] The curved portion 131 includes a first connecting portion 1311 and a second connecting portion 1312. A first flat portion 132 extends from the side of the first connecting portion 1311, and a second flat portion 133 extends from the side of the second connecting portion 1312. An included angle θ is formed between the first connecting portion 1311 and the second connecting portion 1312. In some embodiments, the included angle θ is 60° to 120°.

[0028] In some embodiments, the first connecting portion 1311 is coplanar with the first planar portion 132, and the second connecting portion 1312 is coplanar with the second planar portion 133, to facilitate the manufacturing of the circuit board 10.

[0029] In some embodiments, the circuit board structure 100 includes a plurality of reinforcing plates, which are respectively disposed in the first non-bending area 11, the second non-bending area 13 and the third non-bending area 15 to improve the strength of the non-bending areas and reduce the risk of bending in the non-bending areas.

[0030] In some embodiments, the plurality of reinforcing plates includes a first reinforcing plate 21, a second reinforcing plate 22, and a third reinforcing plate 23. The first reinforcing plate 21 covers a portion of the first non-bending area 11. The second reinforcing plate 22 covers a second non-bending area 13. The third reinforcing plate 23 covers a portion of the third non-bending area 15.

[0031] The first non-bending region 11 includes a first edge portion 11C connected to the first bending region 12, and a first reinforcing plate 21 covers the first edge portion 11C. Along the width direction Y, the first non-bending region 11 includes opposing first sides 11A and second sides 11B, and the first reinforcing plate 21 is disposed from the first side 11A to the second side 11B such that the first reinforcing plate 21 covers the entire first non-bending region 11 in the width direction Y. In some embodiments, the first non-bending region 11 is generally flat, and the first reinforcing plate 21 is also generally flat, and the first reinforcing plate 21 is attached to the surface of the first non-bending region 11. The first reinforcing plate 21 and the first non-bending region 11 can be connected by adhesive.

[0032] Along the width direction Y, the first bending region 12 includes a first side 12A and a second side 12B opposite to each other. In some embodiments, the first side 11A is flush with the first side 12A, and the second side 12B is concave relative to the second side 11B.

[0033] Along the length direction Y, the second non-bending region 13 includes opposing first edge portions 13C and second edge portions 13D. The first edge portion 13C is connected to the first bending region 12, and the second edge portion 13D is connected to the second bending region 14. A second reinforcing plate 22 covers the first edge portion 13C and the second edge portion 13D. In some embodiments, the second reinforcing plate 22 is configured from the first edge portion 13C to the second edge portion 13D such that the second reinforcing plate 22 covers the entire second non-bending region 13 in the length direction X. Along the width direction Y, the second non-bending region 13 includes opposing first sides 13A and 13B. In some embodiments, the first side 13A is flush with the first side 11A, and the second side 13B is flush with the second side 11B. The second reinforcing plate 22 is configured from the first side 13A to the second side 13B such that the second reinforcing plate 22 covers the entire second non-bending region 13 in the width direction Y. The second reinforcing plate 22 is attached to the surface of the second non-bending region 13. The second reinforcing plate 22 and the second non-bending area 13 can be connected by adhesive.

[0034] The second reinforcing plate 22 includes a bent portion 210 and a first flat portion 220 and a second flat portion 230 located on opposite sides of the bent portion 210. The bent portion 210 is disposed on the bent portion 131, the first flat portion 220 is disposed on the first flat portion 132, and the second flat portion 230 is disposed on the second flat portion 133. In some embodiments, the shape of the bent portion 210 is adapted to the shape of the bent portion 131, the shape of the first flat portion 220 is adapted to the shape of the first flat portion 132, and the shape of the second flat portion 230 is adapted to the shape of the second flat portion 133, thereby improving the reinforcing effect of the bent portion 210, the first flat portion 220, and the second flat portion 230 of the second reinforcing plate 22 on the bent portion 131, the first flat portion 132, and the second flat portion 133 of the second non-bending area 13, respectively.

[0035] Along the width direction Y, the second bending region 14 includes a first side 14A and a second side 14B. In some embodiments, the first side 14A of the second bending region 14 is concave relative to the first side 13A of the second non-bending region 13, and the second side 14B of the second bending region 14 is flush with the second side 13B of the second non-bending region 13.

[0036] The third non-bending region 15 includes a first edge 15C connected to the second bending region 14, and a third reinforcing plate 23 covers the first edge 15C. Along the width direction Y, the third non-bending region 15 includes opposing first sides 15A and second sides 15B, and the third reinforcing plate 23 is disposed from the first side 15A to the second side 15B such that the third reinforcing plate 23 covers the entire third non-bending region 15 in the width direction Y. In some embodiments, the third non-bending region 15 is generally flat, and the third reinforcing plate 23 is also generally flat, and the third reinforcing plate 23 is attached to the surface of the third non-bending region 15. The third reinforcing plate 23 and the third non-bending region 15 can be connected by adhesive.

[0037] In some embodiments, the reinforcing plate includes a metal plate and / or a plastic plate, wherein the metal plate may be a steel sheet or the plastic plate may be made of polyimide, fiberglass cloth or the like.

[0038] Please see Figure 3 , Figure 4 and Figure 5 , Figure 4 A cross-sectional view of the bent portion 131 of the second non-bending region 13 and the bent portion 210 of the second reinforcing plate 22 before bending is shown after unfolding. The circuit board 10 includes a first circuit board 30, an adhesive layer 40, and a second circuit board 50. Along the thickness direction Z, the second circuit board 50 is stacked on at least one side of the first circuit board 30 through the adhesive layer 40, and the adhesive layer 40 is located between the first circuit board 30 and the second circuit board 50. In this embodiment, two second circuit boards 50 are respectively bonded to two surfaces of the first circuit board 30 through two adhesive layers 40. In other embodiments, there can be multiple first circuit boards 30 and multiple second circuit boards 50, and adjacent first circuit boards 30 and second circuit boards 50 are bonded by adhesive layers 40 sandwiched between them.

[0039] In some embodiments, the adhesive layer 40 has a first opening 401 and a second opening 402 extending through the adhesive layer 40 along the thickness direction Z. The first opening 401 and the second opening 402 respectively expose portions of the first circuit board 30 and the second circuit board 50. The first opening 401 is located in the first bending region 12, and the second opening 402 is located in the second bending region 14. In some embodiments, viewed along the thickness direction Z, the area in the circuit board 10 corresponding to the first opening 401 is defined as the first bending region 12, and the area in the circuit board 10 corresponding to the second opening 402 is defined as the second bending region 14. By providing the first opening 401 and the second opening 402, the bending stress during bending in the bending region can be reduced.

[0040] Both the first through-slot 101 and the second through-slot 102 extend through the circuit board 10 along the thickness direction Z. The first through-slot 101 extends to one side of the circuit board 10 in the width direction Y, and the first non-bending area 11, the first bending area 12, and the second non-bending area 13 are arranged around the first through-slot 101. The second through-slot 102 extends to the other side of the circuit board 10 in the width direction Y, and the second non-bending area 13, the second bending area 14, and the third non-bending area 15 are arranged around the second through-slot 102.

[0041] In some embodiments, the adhesive layer 40 located in the first non-bending region 11, the second non-bending region 13, and the third non-bending region 15 does not have a through opening.

[0042] The first circuit board 30 includes a first base layer 31, a first conductive line layer 32, and a first cover layer 33. The first conductive line layer 32 is disposed on at least one surface of the first base layer 31, and the first cover layer 33 covers the surface of the first conductive line layer 32 that is away from the first base layer 31.

[0043] The second circuit board 50 includes a second base layer 51, a second conductive line layer 52, and a second cover layer 53. The second conductive line layer 52 is disposed on at least one surface of the second base layer 51, and the second cover layer 53 covers the surface of the second conductive line layer 52 opposite to the second base layer 51. A reinforcing plate is disposed on the surface of the second cover layer 53 opposite to the second conductive line layer 52.

[0044] In some embodiments, the first base layer 31 and the second base layer 51 can each be integrally formed from a flexible dielectric material. The flexible dielectric material may include, but is not limited to, polyimide (PI), polyethylene terephthalate (PET), Teflon, polyamide, polymethyl methacrylate, polycarbonate, or polyamide-ethylene-terephthalate copolymer. The first base layer 31 and the second base layer 51 can be made of the same material.

[0045] In some embodiments, the first base layer 31 and the second base layer 51 located in the first bending region 12 and the second bending region 14 may be formed of a flexible dielectric material, while the first base layer 31 and the second base layer 51 located in the first non-bending region 11, the second non-bending region 13, and the third non-bending region 15 may be formed of a rigid dielectric material. Rigid dielectric materials may include, but are not limited to, epoxy resin, fiberglass cloth, etc.

[0046] In some embodiments, the adhesive layer 40 may be made of epoxy resin or acrylic resin, or it may be a low-flow-rate prepreg film.

[0047] The first cover layer 33 protects the first conductive circuit layer 32, and the second cover layer 53 protects the second conductive circuit layer 52. The first cover layer 33 can be a single-layer structure including a resin layer or a double-layer structure including an adhesive layer and a resin layer. The structure of the second cover layer 53 can be the same as that of the first cover layer 33.

[0048] The circuit board 10 also includes a conductive structure 60. The conductive structure 60 passes through the first base layer 31, the adhesive layer 40, and the second base layer 51, and electrically connects the first conductive line layer 32 and the second conductive line layer 52.

[0049] One embodiment of this application provides a method for manufacturing a circuit board structure, including: A first circuit board, an adhesive layer having a first opening and a second opening, and a second circuit board are provided. The second circuit board is laminated to one side of the first circuit board with an adhesive layer to obtain a laminated structure with a first opening; Multiple reinforcing plates are installed on the side of the second circuit board away from the first circuit board; The stacked structure is processed to form a first non-bending region, a first bending region, a second non-bending region, a second bending region, and a third non-bending region that are connected sequentially along the length direction; The second non-bending area is processed so that the first bending area is intersected with the second bending area.

[0050] In some embodiments, the first circuit board and the second circuit board are manufactured using conventional circuit board fabrication methods.

[0051] In some implementations, a laser-cut layered structure is used to form a first non-bending region, a first bending region, a second non-bending region, a second bending region, and a third non-bending region.

[0052] In some embodiments, the second non-bending area is bent so that the first bending area is intersected relative to the second bending area. Specifically, a shaping jig is used to clamp and fix the first bending area and the second bending area, and a tool is used to push against the second non-bending area to form a bend.

[0053] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with this application are still within the scope of this application.

Claims

1. A circuit board structure, comprising a circuit board, characterized in that, The circuit board includes a first non-bending area, a first bending area, a second non-bending area, a second bending area, and a third non-bending area connected sequentially along the length of the circuit board, wherein the first bending area is arranged to cross the second bending area.

2. The circuit board structure as described in claim 1, characterized in that, Along the width direction of the circuit board, the second non-bending area includes a bent portion and a first planar portion and a second planar portion located on opposite sides of the bent portion; along the length direction of the circuit board, the first bending area is located between the first non-bending area and the first planar portion, and the second bending area is located between the second planar portion and the third non-bending area; the first planar portion is connected to the first bending area and separated from the third non-bending area, and the second planar portion is connected to the second bending area and separated from the first non-bending area.

3. The circuit board structure as described in claim 2, characterized in that, A first through groove is formed between the first non-bending area, the first bending area and the bending portion, and a second through groove is formed between the second bending area, the third non-bending area and the bending portion.

4. The circuit board structure as described in claim 2, characterized in that, The curved portion includes a first connecting portion and a second connecting portion. The first flat portion extends from the side of the first connecting portion, and the second flat portion extends from the side of the second connecting portion. The included angle between the first connecting portion and the second connecting portion is 60°~120°.

5. The circuit board structure as described in claim 2, characterized in that, The circuit board structure includes a first reinforcing plate, a second reinforcing plate, and a third reinforcing plate. The first reinforcing plate covers a portion of the first non-bending area, the second reinforcing plate covers the second non-bending area, and the third reinforcing plate covers a portion of the third non-bending area.

6. The circuit board structure as described in claim 5, characterized in that, The first bending area includes a first edge portion connected to the first bending area, the third non-bending area includes a first edge portion connected to the second bending area, the first reinforcing plate covers the first edge portion of the first bending area, and the third reinforcing plate covers the first edge portion of the third non-bending area.

7. The circuit board structure as described in claim 5, characterized in that, The shape of the second reinforcing plate is adapted to the shape of the second non-bending area.

8. The circuit board structure as described in claim 1, characterized in that, The circuit board includes a first circuit substrate, an adhesive layer, and a second circuit substrate. The second circuit substrate is stacked on at least one side of the first circuit substrate through the adhesive layer. The adhesive layer has a first opening and a second opening. The first opening exposes a portion of the first circuit substrate and a portion of the second circuit substrate, and the second opening exposes a portion of the first circuit substrate and a portion of the second circuit substrate. The first opening is located in the first bending area, and the second opening is located in the second bending area.

9. A method for manufacturing a circuit board structure as described in any one of claims 1-8, characterized in that, include: The second circuit board is laminated to one side of the first circuit board with an adhesive layer to obtain a laminated structure; The stacked structure is processed to form a first non-bending area, a first bending area, a second non-bending area, a second bending area, and a third non-bending area that are sequentially connected along the length of the circuit board; The second non-bending area is processed so that the first bending area is arranged to intersect with the second bending area.

10. The method for manufacturing the circuit board structure as described in claim 9, characterized in that, Also includes: Multiple reinforcing plates are installed on the side of the second circuit board that is away from the first circuit board.

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