A manufacturing process for an asymmetric rigid-flex board

Abstract

The present invention discloses a manufacturing process of an asymmetric rigid-flexible board, comprising the following steps: laminating and bonding a first rigid core board on opposite sides of a flexible core board to form a thin rigid-flexible layer; performing a windowing process on the first rigid core board and arranging a gasket in the window, forming a flexure area at the window; laminating and bonding a second rigid core board on opposite sides of the thin rigid-flexible layer to form a thick rigid-flexible layer; performing a windowing process on the second rigid core board, with the adhesive layer portion of the second rigid core board located above the gasket; laminating and bonding copper foil on opposite sides of the thick rigid-flexible layer to form a stacked structure and pressing; then copper-plating the stacked structure, making outer layer circuits, solder masking and surface treatment, uncovering and removing the gasket to obtain an asymmetric rigid-flexible board. The present invention can manufacture an asymmetric rigid-flexible board by one-time pressing, with a short production cycle, and the asymmetric rigid-flexible board has no solder mask color difference, is not prone to board explosion, and has a high yield.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit boards, and in particular to a manufacturing process of an asymmetric rigid-flexible board. Background Art

[0002] Rigid-flex circuit boards combine the flexibility of flexible circuit boards with the durability of rigid circuit boards, enabling three-dimensional assembly under different conditions. They are widely used in industry, high-end medical, military equipment, and other consumer portable electronics.

[0003] Due to the development needs of multi-modular electronic products, in order to meet the assembly requirements of different application functions of each module, in the same rigid-flex PCB, some areas can be satisfied with low-layer wiring, while other areas require higher-layer wiring to meet more complex functions, or the number of layers is the same, so asymmetric rigid-flex PCBs have emerged.

[0004] The specific production process of the existing asymmetric rigid-flexible circuit board is as follows: Step 1, the flexible core board and the first rigid core board are stacked and pressed for the first time to form a thin rigid-flexible board. After pressing, the thin rigid-flexible board is drilled, perforated, lined, soldered and surface treated; Step 2, the thin rigid-flexible board and the second rigid core board are stacked and windowed and pressed for the second time to form a thick rigid-flexible board. After pressing, the thick rigid-flexible board is drilled, perforated, lined, soldered and surface treated; Step 3, the rigid-flexible area is uncovered to obtain an asymmetric rigid-flexible circuit board.

[0005] However, this production method has the following defects: it adopts a secondary pressing process, which has a long production cycle; the deformation of thin rigid-flex boards and thick rigid-flex boards during the secondary pressing is different, which makes it easy for the boards to burst during pressing, and two solder masks are required. The rigid-flex circuit boards are prone to solder mask color differences and appearance defects, resulting in low production yield. Summary of the Invention

[0006] The purpose of the embodiments of the present invention is to provide a manufacturing process for an asymmetric rigid-flex circuit board, which can effectively shorten the production cycle, has no solder mask color difference, and has a high production yield.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A manufacturing process for an asymmetric rigid-flex circuit board is provided, comprising the following steps:

[0009] Step S10: providing a flexible core board and a first rigid core board, laminating and bonding the first rigid core board on opposite sides of the flexible core board to form a thin rigid-flexible bonding layer, and performing a window processing on the first rigid core board to form a flexure area at the window opening;

[0010] Step S20: placing a gasket in the window of the first rigid core board;

[0011] Step S30: Providing a second rigid core board, laminating and bonding the second rigid core board on opposite sides of the thin rigid-flex layer to form a thick rigid-flex layer, and performing a windowing process on the second rigid core board so that the thickness of the thick rigid-flex layer is different on opposite sides of the flexure zone. The adhesive layer portions to which the second rigid core boards are bonded are located directly above the gasket.

[0012] Step S40: providing copper foils, laminating and bonding the copper foils on opposite sides of the thick rigid-flex layer to form a laminated structure;

[0013] Step S50: Pressing the stacked structure so that the stacked structure forms a thick rigid-flexible bonding area and a thin rigid-flexible bonding area on opposite sides of the flexure area;

[0014] Step S60, performing copper plating, outer layer circuit making, solder resist and surface treatment on the stacked structure;

[0015] Step S70: uncover the stacked structure to expose and remove the gasket to obtain the asymmetric rigid-flex board.

[0016] As a preferred solution of the manufacturing process of the asymmetric rigid-flex board, before step S10, the process further includes step S11, performing panel design on the asymmetric rigid-flex board;

[0017] The asymmetric rigid-flexible board includes multiple first areas and multiple second areas, the first areas are used to be designed as the thin rigid-flexible bonding area, and the second areas are used to be designed as the thick rigid-flexible bonding area. The multiple first areas are arranged at intervals along the first direction to form a row of the first areas, and the multiple rows of the first areas are arranged at intervals along the second direction. The first direction and the second direction are perpendicular. The multiple second areas are arranged at intervals along the first direction to form a row of the second areas, and two rows of the second areas are arranged between two adjacent rows of the first areas.

[0018] As a preferred solution for the manufacturing process of an asymmetric rigid-flexible board, in step S30, the bonding layers bonding the first copper foil and the second rigid core board are respectively the third bonding layer and the fourth bonding layer, the length of the third bonding layer is the same as the length of the fourth bonding layer, and there is a spacing L1 between the third bonding layer and the fourth bonding layer and the thin rigid-flexible bonding area, and L1 is 1 mm to 5 mm.

[0019] As a preferred solution for the manufacturing process of an asymmetric rigid-flexible board, in step S10, the flexible core board and the first rigid core board are bonded by a second adhesive layer, and the second adhesive layer is subjected to window opening treatment at the window opening position corresponding to the first rigid core board. In step S20, the thickness of the gasket is H1, and the sum of the thickness of the first rigid core board and the second adhesive layer is H2, H1=H2±0.05mm.

[0020] As a preferred solution for the manufacturing process of the asymmetric rigid-flex board, there is a distance L2 between the gasket and the thick rigid-flex area, and there is a distance L3 between the gasket and the thin rigid-flex area, and both L2 and L3 are 0.2mm to 1mm.

[0021] As a preferred solution for the manufacturing process of the asymmetric rigid-flex board, before step S10, step S12 is further included, providing a covering layer, and covering the covering layer on the flexing area of the flexible core board.

[0022] As a preferred solution for the manufacturing process of the asymmetric rigid-flex board, the flexible core board is a single-layer board or a multi-layer board.

[0023] As a preferred solution for the manufacturing process of an asymmetric rigid-flexible board, in step S10, the flexible core board includes a first core board and a second core board, and the first core board and the second core board are bonded by a first adhesive layer.

[0024] As a preferred solution for the manufacturing process of the asymmetric rigid-flex board, the flexible core board, the first rigid core board, the second rigid core board, and the copper foil are all bonded using a flowable prepreg or a non-flowable prepreg.

[0025] As a preferred solution for the manufacturing process of the asymmetric rigid-flex board, in step S60, the pressing parameters are: pressure of 150-550 psi, hot pressing temperature of 185-210° C., and pressing time of 60-180 min.

[0026] The beneficial effects of the present invention are:

[0027] (1) The asymmetric rigid-flexible board is made by one-time pressing, which can effectively shorten the production cycle of the asymmetric rigid-flexible board. At the same time, the deformation of the entire stacked structure tends to be consistent during the pressing process, and it is not easy to cause the board to explode. The solder mask can be completed once after pressing, which can effectively avoid the secondary solder mask causing the thin rigid-flexible bonding area and the thick rigid-flexible bonding area to have solder mask color difference, thereby solving the appearance defect problem of the asymmetric rigid-flexible board and avoiding the dust adhering to the outer circuit board after the first solder mask.

[0028] (2) The copper foil can cover the thick rigid-flexible bonding area and the thin rigid-flexible bonding area at the same time, so that the copper foil can serve as the outer layer of the thick rigid-flexible bonding area and the thin rigid-flexible bonding area at the same time after lamination. At the same time, during the lamination process, the part of the adhesive layer bonding the first copper foil and the second rigid core board suspended above the gasket will tilt downward and abut against the gasket to form a supporting slope, and support the part of the copper foil located above the gasket, so that the copper foil forms a stepped structure after lamination. The part of the copper foil in the thick rigid-flexible bonding area and the part of the thin rigid-flexible bonding area can be smoothly transitioned through the transition slope, so that when making the outer layer circuit, the entire film can be pasted to the outer surface of the copper foil at one time, which is convenient for film pasting, thereby improving the lamination yield and the production efficiency of the outer layer circuit, and further shortening the production cycle of the asymmetric rigid-flexible board. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0030] Figure 1 This is a top view of the asymmetric rigid-flex board according to an embodiment of the present invention.

[0031] Figure 2 2 is a cross-sectional view of the asymmetric rigid-flex board according to an embodiment of the present invention.

[0032] Figure 3 Schematic diagram of the structure of the thin rigid-flex bonding layer prepared in step S10 and step S20 in the manufacturing process of an embodiment of the present invention.

[0033] Figure 4 Schematic diagram of the structure of the stacked structure prepared in step S30 and step S40 in the manufacturing process of an embodiment of the present invention.

[0034] Figure 5 Schematic diagram of the structure of the stacked structure prepared in step S50 in the manufacturing process of an embodiment of the present invention.

[0035] Figure 6 Schematic diagram of the structure of the stacked structure prepared in step S60 in the manufacturing process of an embodiment of the present invention.

[0036] In the picture:

[0037] 1. Flexible core board; 101. First core board; 102. Second core board; 103. First bonding layer; 2. First rigid core board; 3. Second bonding layer; 4. Third bonding layer; 5. Second rigid core board; 6. Fourth bonding layer; 7. Copper foil; 8. Flexure area; 9. Thin rigid-flexible bonding area; 10. Thick rigid-flexible bonding area; 11. Gasket; 12. Covering layer; 13. Transition slope; 14. Copper hole; 15. Solder point. DETAILED DESCRIPTION

[0038] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present invention more clearly understood, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It is apparent that the described embodiments are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0039] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0040] Reference Figure 1 and Figure 2 The asymmetric rigid-flex board includes at least one flexure area 8, and a thin rigid-flexure area 9 and a thick rigid-flexure area 10 are provided on opposite sides of each flexure area 8.

[0041] Reference Figures 2 to 6 The present invention provides a manufacturing process for an asymmetric rigid-flex board, comprising the following steps:

[0042] Step S10: providing a flexible core board 1 and a first rigid core board 2, laminating and bonding the first rigid core board 2 on opposite sides of the flexible core board 1 to form a thin rigid-flexible bonding layer;

[0043] A window is opened on the first rigid core board 2 to expose a portion of the flexible core board 1, so that the thin rigid-flexible layer forms a flexible area 8 at the window;

[0044] Step S20, placing a gasket 11 in the window of the first rigid core plate 2;

[0045] Step S30: providing a second rigid core board 5, and sequentially laminating and bonding the second rigid core boards 5 on opposite sides of the thin rigid-flexible bonding layer to form a thick rigid-flexible bonding layer;

[0046] The second rigid core plate 5 is subjected to a windowing process so that the thickness of the thick rigid-flex layer is different on opposite sides of the flexure area 8, wherein the portion of the adhesive layer bonded to the second rigid core plate 5 is located directly above the gasket 11;

[0047] Step S40: Provide copper foil 7, laminate and bond the copper foil 7 on both sides of the thick rigid-flexible bonding layer to form a laminated structure, refer to Figure 4, the laminated structure is composed of a flexible core board 1, a first rigid core board 2, a second rigid core board 5 and a copper foil 7 and an adhesive layer thereof;

[0048] Step S50: Laminating the laminated structure so that a thick rigid-flexible bonding region 10 and a thin rigid-flexible bonding region 9 are formed on opposite sides of the flexure region 8, wherein the copper foil 7 serves as the outer layer of both the thick rigid-flexible bonding region 10 and the thin rigid-flexible bonding region 9.

[0049] Step S60: performing copper plating, forming outer layer circuits, solder resist and surface treatment on the stacked structure;

[0050] Step S70 , uncovering the stacked structure to remove the portion of the stacked structure located above the gasket 11 , thereby exposing the gasket 11 and removing it to obtain an asymmetric rigid-flex board.

[0051] In the above operation, by first opening windows in the first rigid core board 2 and the second rigid core board 5 respectively, and then stacking the flexible core board 1, the first rigid core board 2, the second rigid core board 5 and the copper foil 7 in sequence, a stacked structure with different thicknesses on opposite sides of the flexure area 8 can be formed, thereby achieving a one-time pressing to obtain an asymmetric rigid-flexible board with a thick rigid-flexible bonding area 10 and a thin rigid-flexible bonding area 9. This design can not only effectively shorten the production cycle of the asymmetric rigid-flexible board, but also make the deformation of the entire stacked structure tend to be consistent during the pressing process, making it less likely to explode, and can also complete the solder masking in one step after pressing, which can effectively avoid the secondary solder masking that causes the thin rigid-flexible bonding area 9 and the thick rigid-flexible bonding area 10 to have solder mask color difference, thereby solving the appearance defect problem of the asymmetric rigid-flexible board, and at the same time can avoid the dust adhering to the outer circuit board after the first solder masking;

[0052] Reference Figure 4 , the copper foil 7 has no window treatment and can cover both the thick rigid-flexible bonding area 10 and the thin rigid-flexible bonding area 9. Figure 5 After lamination, the copper foil 7 can serve as the outer layer of the thick rigid-flexible bonding area 10 and the thin rigid-flexible bonding area 9 at the same time. At the same time, during the lamination process, the part of the adhesive layer of the second rigid core board 5 suspended above the gasket 11 will tilt downward and abut against the gasket 11 to form a supporting slope, and support the part of the copper foil 7 located above the gasket 11, so that the copper foil 7 forms a stepped structure after lamination. The part of the copper foil 7 in the thick rigid-flexible bonding area 10 and the part of the thin rigid-flexible bonding area 9 can be smoothly transitioned through the transition slope 13, so that when making the outer layer circuit, the entire film can be pasted to the outer surface of the copper foil 7 at one time, which is convenient for film pasting, thereby improving the pasting yield and the production efficiency of the outer layer circuit, and further shortening the production cycle of the asymmetric rigid-flexible board.

[0053] Specifically, refer to Figures 2 to 6In step S10, the flexible core board 1 and the first rigid core board 2 are bonded by the second adhesive layer 3, and the second adhesive layer 3 is subjected to window opening treatment at the position corresponding to the window opening of the first rigid core board 2 to expose the flexible core board 1.

[0054] Furthermore, in step S20 , the gasket 11 is disposed in the windows of the second adhesive layer 3 and the first rigid core plate 2 simultaneously to prevent the second adhesive layer 3 from being deformed and overflowing into the flexure area 8 during lamination.

[0055] For example, refer to Figure 3 The thickness of the gasket 11 is H1, the sum of the thickness of the first rigid core board 2 and the second adhesive layer 3 is H2, and H1 = H2 ± 0.05 mm.

[0056] Preferably, the width of the gasket 11 is smaller than the width of the window of the first rigid core board 2 , so as to facilitate placement of the gasket 11 in the windows of both the first rigid core board 2 and the second adhesive layer 3 .

[0057] Among them, reference Figure 5 The spacing between the gasket 11 and the thick rigid-flexible bonding area 10 is L2, and the spacing between the gasket 11 and the thin rigid-flexible bonding area 9 is L3. Both L2 and L3 are 0.2mm to 1mm. Preferably, L2 and L3 are 0.3mm, 0.5mm, 0.8mm, etc. If L2 and L3 are too large, the gasket 11 will not be able to prevent glue overflow. If L2 and L3 are too small, it will increase the difficulty of installing the gasket 11. This design can ensure that the gasket 11 can prevent glue overflow and can reduce the difficulty of installing the gasket 11.

[0058] Specifically, the flexible core board 1 is a single-layer board or a multi-layer board.

[0059] In this embodiment, referring to Figures 2 to 6 , the flexible core board 1 is a double-layer board.

[0060] In step S10 , the flexible core board 1 includes a first core board 101 and a second core board 102 , and the first core board 101 and the second core board 102 are bonded together by a first adhesive layer 103 .

[0061] Specifically, the first adhesive layer 103 is subjected to a windowing process corresponding to the flexure area 8 .

[0062] Specifically, the copper foil 7 is adhered to the opposite sides of the thick rigid-flex bonding layer through the fourth adhesive layer 6 .

[0063] It should be noted that the thin rigid-flexible bonding area 9 is composed of a flexible core board 1, a second adhesive layer 3, a first rigid core board 2, a fourth adhesive layer 6 and a copper foil 7, and the thick rigid-flexible bonding area 10 is composed of a flexible core board 1, a second adhesive layer 3, a first rigid core board 2, a third adhesive layer 4, a second rigid core board 5, a fourth adhesive layer 6 and a copper foil 7.

[0064] Specifically, before step S10, step S11 is also included, designing the panel of the asymmetric rigid-flex board, that is, designing the arrangement positions of the thick rigid-flex area 10 and the thin rigid-flex area 9 of the asymmetric rigid-flex board.

[0065] In this embodiment, referring to Figure 1 The asymmetric rigid-flex board includes multiple first regions and multiple second regions. The first regions are designed to be thin rigid-flex regions 9, and the second regions are designed to be thick rigid-flex regions 10. The multiple first regions are spaced apart along the first direction to form a row of first regions. The multiple rows of first regions are spaced apart along the second direction, with the first and second directions being perpendicular. The multiple second regions are spaced apart along the first direction to form a row of second regions. Two rows of spaced second regions are provided between two adjacent rows of first regions. This design enables two rows of thick rigid-flex regions 10 to be provided between two adjacent rows of thin rigid-flex regions 9 on the manufactured asymmetric rigid-flex board, ensuring that the copper foil 7 of the laminated structure forms a "convex" stepped structure after lamination, facilitating film application.

[0066] Specifically, refer to Figures 2 to 6 Before step S10, step 12 is also included, in which a covering layer 12 is stacked on the flexing area 8 of the flexible core board 1, and a gasket 11 is attached to the side of the covering layer 112 facing away from the flexible core board 1 to protect the circuit of the flexible core board 1 in the flexing area 8 to prevent the circuit from being oxidized or damaged.

[0067] Illustratively, the cover layer 12 is a cover film.

[0068] Preferably, the covering layer 12 is inserted into the portion of the second adhesive layer 3 located in the thick rigid-flexible bonding area 10 and the portion located in the thin rigid-flexible bonding area 9 on opposite sides, and the covering layer 12 is only inserted into a portion of the second adhesive layer 3, so that most of the second adhesive layer 3 can be bonded to the flexible core board 1. Since the bonding force between the covering layer 12 and the second adhesive layer 3 is relatively poor, and the expansion coefficient of the covering layer 12 is large, after the covering layer 12 is directly applied to cover the entire flexible core board 1 and pressed together, the asymmetric rigid-flexible board is prone to delamination. This design can reduce the covering layer 12, so that most of the second adhesive layer 3 is directly bonded to the flexible core board 1. The bonding force between the flexible core board 1 and the second adhesive layer 3 is relatively high, which can effectively reduce the delamination of the asymmetric rigid-flexible board.

[0069] Specifically, refer to Figures 4 to 6 In step S30 , the bonding layer for bonding the second rigid core panel 5 is the third bonding layer 4 , that is, the first rigid core panel 2 is bonded to the second rigid core panel 5 through the third bonding layer 4 .

[0070] Further, refer to Figure 4A spacing L1 is provided between the third adhesive layer 4 and the thin rigid-flex region 9, with L1 ranging from 1 mm to 5 mm. Optionally, L1 can be 3 mm, 3.5 mm, 4 mm, 5 mm, etc. This design effectively creates a slope in the flex region 8 after the third adhesive layer 4 is laminated, thereby ensuring that the copper foil 7 forms a transition slope 13.

[0071] For example, the flexible core board 1, the first rigid core board 2, the second rigid core board 5, and the copper foil 7 are all bonded with a flowable semi-cured sheet or a non-flowable semi-cured sheet, that is, the first adhesive layer 103, the second adhesive layer 3, the third adhesive layer 4, and the fourth adhesive layer 6 can be a flowable semi-cured sheet or a non-flowable semi-cured sheet.

[0072] Specifically, in step S50 , the pressing parameters are: pressure of 150 to 550 psi, hot pressing temperature of 185 to 210° C., and pressing time of 60 to 180 min.

[0073] Specifically, refer to Figure 6 In step S60, the stacked structure is formed with copper holes 14 by copper plating, and solder joints 15 by solder resist.

[0074] It should be noted that the copper plating, outer layer circuit making, solder resist and surface treatment processes in step S60 and the cover removal process in step S70 can adopt existing processing techniques and will not be described in detail here.

[0075] In the description herein, it should be understood that the terms "upper," "lower," "left," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0076] In this specification, reference to terms such as "one embodiment" or "example" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0077] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0078] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will readily conceive of other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the present invention.

Claims

1. A manufacturing process for an asymmetric rigid-flex board, characterized in that: The following steps are involved: Step S10: providing a flexible core board and a first rigid core board, laminating and bonding the first rigid core board on opposite sides of the flexible core board to form a thin rigid-flexible bonding layer, and performing a window processing on the first rigid core board to form a flexure area at the window opening; Step S20: placing a gasket in the window of the first rigid core board; Step S30: providing a second rigid core board, laminating and bonding the second rigid core board on opposite sides of the thin rigid-flexible layer to form a thick rigid-flexible layer, performing a windowing process on the second rigid core board so that the thickness of the thick rigid-flexible layer is different on opposite sides of the flexure region, wherein a portion of the adhesive layer bonded to the second rigid core board is suspended directly above the gasket; Step S40: providing copper foils, laminating and bonding the copper foils on opposite sides of the thick rigid-flex layer to form a laminated structure; Step S50: Laminating the stacked structure so that a thick rigid-flexible bonding area and a thin rigid-flexible bonding area are formed on opposite sides of the flexure area. During the lamination process, the portion of the adhesive layer of the second rigid core board suspended above the gasket tilts downward and abuts against the gasket to form a supporting slope, thereby supporting the portion of the copper foil above the gasket, so that the copper foil forms a stepped structure after lamination. Step S60, performing copper plating, outer layer circuit making, solder resist and surface treatment on the stacked structure; Step S70: uncover the stacked structure to expose and remove the gasket to obtain the asymmetric rigid-flex board.

2. The manufacturing process of the asymmetric rigid-flex board according to claim 1, characterized in that: Before step S10, the method further includes step S11, performing panel design on the asymmetric rigid-flex board; The asymmetric rigid-flexible board includes multiple first areas and multiple second areas, the first areas are used to be designed as the thin rigid-flexible bonding area, and the second areas are used to be designed as the thick rigid-flexible bonding area. The multiple first areas are arranged at intervals along the first direction to form a row of the first areas, and the multiple rows of the first areas are arranged at intervals along the second direction. The first direction and the second direction are perpendicular. The multiple second areas are arranged at intervals along the first direction to form a row of the second areas, and two rows of the second areas are arranged between two adjacent rows of the first areas.

3. The manufacturing process of the asymmetric rigid-flex board according to claim 1, characterized in that: In the step S30, the bonding layer for bonding the second rigid core board is a third bonding layer, and there is a distance L1 between the third bonding layer and the thin rigid-flex bonding area, and L1 is 1 mm to 5 mm.

4. The manufacturing process of the asymmetric rigid-flex board according to any one of claims 1 to 3, characterized in that: In the step S10, the flexible core board and the first rigid core board are bonded by a second adhesive layer, and the second adhesive layer is subjected to window opening treatment at the window opening position corresponding to the first rigid core board. In the step S20, the thickness of the gasket is H1, and the sum of the thicknesses of the first rigid core board and the second adhesive layer is H2, H1=H2±0.05mm.

5. The manufacturing process of the asymmetric rigid-flex board according to claim 4, characterized in that: There is a distance L2 between the gasket and the thick rigid-flexible bonding area, and there is a distance L3 between the gasket and the thin rigid-flexible bonding area. Both L2 and L3 are 0.2mm to 1mm.

6. The manufacturing process of the asymmetric rigid-flex board according to any one of claims 1 to 3, characterized in that: Before the step S10, the method further includes a step S12 of providing a covering layer, and covering the covering layer on the flexure area of the flexible core board.

7. The manufacturing process of an asymmetric rigid-flex board according to any one of claims 1 to 3, characterized in that: The flexible core board is a single-layer board or a multi-layer board.

8. The manufacturing process of the asymmetric rigid-flex board according to claim 7, characterized in that: In step S10 , the flexible core panel includes a first core panel and a second core panel, and the first core panel and the second core panel are bonded together by a first adhesive layer.

9. The manufacturing process of an asymmetric rigid-flex board according to any one of claims 1 to 3, characterized in that: The flexible core board, the first rigid core board, the second rigid core board, and the copper foil are all bonded by using a flowable prepreg or a non-flowable prepreg.

10. The manufacturing process of an asymmetric rigid-flex board according to any one of claims 1 to 3, characterized in that: In the step S50, the pressing parameters are: pressure of 150-550 psi, hot pressing temperature of 185-210° C., and pressing time of 60-180 min.

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