Method for manufacturing rigid-flex circuit board and rigid-flex circuit board

Abstract

The present invention provides a method for manufacturing a rigid-flexible circuit board and a rigid-flexible circuit board, and relates to the technical field of circuit boards to solve the technical problem of the complicated manufacturing process of existing rigid-flexible circuit boards. The method for manufacturing a rigid-flexible circuit board provided by the present invention includes the following steps: manufacturing a flexible layer, forming a flexible area on the flexible layer; manufacturing a semi-cured sheet, forming a pre-hollowed area on the semi-cured sheet; fixing the flexible layer to the first surface of the semi-cured sheet, and the pre-hollowed area corresponds to the flexible area; forming a rigid layer on the second surface of the semi-cured sheet, the first surface and the second surface being two opposite surfaces of the semi-cured sheet; forming an open cover area on the rigid layer; wherein the open cover area corresponds to the pre-hollowed area and the flexible area, the open cover area is connected to the pre-hollowed area, and the flexible area is exposed. The method for manufacturing a rigid-flexible circuit board of the present invention can simplify the manufacturing process of the rigid-flexible circuit board.

Description

Technical Field

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

[0002] Rigid-flex printed circuit boards based on soft substrates are bendable and can be assembled in three dimensions. They adapt to the needs of miniaturization and integration of electronic terminal products and are increasingly widely used in many scenarios with special design and assembly requirements, further meeting the personalized design, special performance and application needs of electronic products.

[0003] In the processing of rigid-flexible circuit boards, the mixed pressing of rigid boards and flexible layers, as well as the precise opening of the flexible area, are key technologies for this type of product. In the traditional pressing and opening process, a layer of pure adhesive (AD) and polyimide (PI) are usually pressed on the surface of the flexible layer, and then a semi-cured sheet (epoxy resin PP) is normally pressed on the surface of the pure adhesive and polyimide to form an integrated circuit board product for full-process processing during the inner layer production process. After the circuit board is processed to the outer layer process, the opening is currently mainly performed at the specified position of the inner layer of the circuit board by laser cutting or controlled depth drilling, and then the pure adhesive is manually removed to ensure the accuracy and quality of the opening process.

[0004] The existing process for manufacturing rigid-flex circuit boards is relatively complicated. Summary of the Invention

[0005] In order to solve at least one of the problems mentioned in the background technology, the present invention provides a method for manufacturing a rigid-flexible circuit board and a rigid-flexible circuit board, so as to simplify the manufacturing process of the rigid-flexible circuit board.

[0006] In order to achieve the above objectives, in a first aspect, the present invention provides a method for manufacturing a rigid-flex circuit board, comprising the following steps:

[0007] making a flexible layer and forming a flexible area on the flexible layer;

[0008] Making a prepreg and forming a pre-scooped area on the prepreg;

[0009] The flexible layer is fixedly connected to the first surface of the prepreg, and the pre-hollowed area corresponds to the flexible area;

[0010] forming a rigid layer on the second surface of the prepreg, wherein the first surface and the second surface are two opposite surfaces of the prepreg;

[0011] An opening area is formed on the rigid layer, wherein the opening area corresponds to the pre-scooped area and the flexible area, and the opening area is connected to the pre-scooped area and exposes the flexible area.

[0012] In a possible implementation manner, after forming the cover-opening area on the rigid layer, the method further includes:

[0013] Remove the residual glue around the opening area.

[0014] In a possible implementation, removing the residual glue around the cover opening area includes:

[0015] Laser cutting is used to remove the residual glue around the opening area.

[0016] In a possible implementation, the manufacturing of the flexible layer includes:

[0017] Cutting the soft board substrate to obtain a flexible substrate;

[0018] The flexible layer circuit is manufactured on the flexible substrate through the processes of drilling, laminating, exposing, developing, etching and stripping;

[0019] Automated optical inspection of flexible substrates;

[0020] Browning treatment;

[0021] A cover film is attached to the surface of the flexible layer and windows are opened.

[0022] In one possible implementation, the process of making a prepreg includes:

[0023] A positioning hole is provided on the prepreg, wherein the positioning hole is used to position the prepreg;

[0024] Dividing a circuit layout area on the prepreg, wherein the circuit layout area includes a plurality of circuit layout unit areas;

[0025] A hollowing process is performed on at least a portion of the prepreg in the circuit arrangement unit area to form the pre-hollowing area.

[0026] In a possible implementation manner, the fixed connection between the prepreg and the flexible layer includes:

[0027] Aligning the positioning points on the flexible layer with the positioning holes of the prepreg;

[0028] The flexible layer and the prepreg are fixedly connected after being matched; wherein the flexible area of ​​the flexible layer corresponds to the pre-hollowed area.

[0029] In a possible implementation manner, the step of forming the open cover area on the rigid layer includes:

[0030] performing a decapping process on a side of the rigid layer away from the prepreg;

[0031] The pre-hollowed area and the flexible area covered by the rigid layer are exposed, and the cover-opening area is formed.

[0032] In a possible implementation, the circuit layout area is a rectangular area, and there are a plurality of positioning holes, which are spaced apart around the periphery of the circuit layout area.

[0033] In a possible implementation manner, the prepreg includes a low-flow prepreg.

[0034] In a second aspect, the present invention provides a rigid-flexible circuit board, which is prepared using the method for manufacturing a rigid-flexible circuit board as described above, wherein the rigid-flexible circuit board includes a flexible layer, a prepreg, and a rigid layer;

[0035] The flexible layer and the rigid layer are respectively located on the surfaces of the prepreg on opposite sides, the flexible layer has a flexible area, the prepreg has a pre-hollowed area, and the rigid layer has an open cover area;

[0036] The flexible area, the pre-scooping area and the lid opening area all correspond;

[0037] The cover opening area is communicated with the pre-scooping area and exposes the flexible area.

[0038] The present invention's method for manufacturing a rigid-flex circuit board and the rigid-flex circuit board utilizes a method for pre-treating the flexible layer and the prepreg, prior to laminating the flexible layer and the prepreg, to hollow out the area corresponding to the flexible layer's flexible region. After laminating the prepreg and the flexible layer and then sequentially processing the prepreg to the outer layer, the rigid layer covering the flexible region is removed, thereby directly exposing the flexible region without removing the prepreg over the flexible region. Compared to existing rigid-flex circuit board manufacturing processes, this method eliminates the steps of applying, cutting, and manually removing pure adhesive, simplifying the rigid-flex circuit board manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1A schematic diagram of a process for manufacturing a rigid-flexible circuit board according to the first embodiment of the present invention;

[0041] Figure 2 A schematic structural diagram of a prepreg provided in Example 1 of the present invention;

[0042] Figure 3 A schematic structural diagram of a manufactured prepreg provided in Example 1 of the present invention;

[0043] Figure 4 This is a structural diagram of a rigid-flex circuit board provided in Example 2 of the present invention.

[0044] Description of reference numerals:

[0045] 1-flexible layer, 11-flexible area, 12-rigid area, 2-prepreg, 21-positioning hole, 22-pre-hollowed area, 23-circuit layout area, 24-circuit layout unit area, 3-rigid layer, 31-opening area. DETAILED DESCRIPTION

[0046] In the processing of rigid-flexible circuit boards, mixed pressing of soft and hard boards and precise decapping of soft boards are key technologies for this type of product. In the traditional pressing and decapping process, a layer of pure adhesive (AD) and polyimide (PI) are usually pressed on the surface of the soft board layer, and then a semi-cured sheet 2 (epoxy resin PP) is normally pressed on the surface of the pure adhesive and polyimide to form an integrated circuit board product for full-process processing during the inner layer production process. After the circuit board is processed to the outer layer process, it is currently mainly decapped at the specified position of the inner layer of the circuit board through laser cutting or controlled deep drilling, and then the pure adhesive is removed, while ensuring the accuracy and quality of the decapping process.

[0047] This method of opening the lid has the following defects: first, it adds a quick pressing process of pure glue and a cutting process of pure glue, which is long and relatively difficult; second, it increases the cost of the process and auxiliary materials, and the processing cost is high; third, it requires multiple manual operations, is highly dependent on manual labor, and is not suitable for large-scale production; moreover, the cutting operation is repeated at the opening position, and the processing accuracy poses a certain risk to product quality.

[0048] The present invention provides a method for manufacturing a rigid-flexible circuit board. Compared to the conventional process of opening the cover in rigid-flexible circuit boards, this method eliminates the steps of applying, cutting, and manually removing pure adhesive. This simplifies the manufacturing process for rigid-flexible circuit boards, effectively shortening product processing time and reducing production costs. Furthermore, the integrity and processing accuracy of the opening position are ensured. Furthermore, the method reduces reliance on manual labor in multiple steps, reduces the chance of direct human contact with the board surface, and reduces quality risks such as scratches, breaks, cracks, and adhesive residue during the process.

[0049] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be understood as limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings.

[0050] Example 1

[0051] The first embodiment of the present invention provides a method for manufacturing a rigid-flexible circuit board, referring to Figure 1 As shown, it includes the following steps:

[0052] S100, manufacturing a flexible layer and forming a flexible area on the flexible layer;

[0053] S200, making a prepreg and forming a pre-fishing area on the prepreg;

[0054] S300, the flexible layer is fixedly connected to the first surface of the prepreg, and the pre-hollowed area corresponds to the flexible area.

[0055] S400, forming a rigid layer on the second surface of the prepreg, where the first surface and the second surface are two opposite surfaces of the prepreg;

[0056] S500, forming an opening area on the rigid layer; wherein the opening area corresponds to the pre-scooped area and the flexible area, the opening area is connected to the pre-scooped area, and the flexible area is exposed.

[0057] The method for manufacturing a rigid-flexible circuit board of the present invention processes a pre-hollowed area 22 corresponding to the flexible area 11 on the semi-cured sheet during the process of manufacturing the semi-cured sheet 2; after manufacturing the rigid layer 3, the flexible area 11 can be directly exposed by removing the rigid layer 3 covering the pre-hollowed area 22, thereby avoiding damage to the flexible area 11 when removing the semi-cured sheet 2 on the flexible area 11; thus, there is no need to press a layer of pure glue and polyimide on the surface of the flexible layer 1. Therefore, compared with the existing manufacturing method, the manufacturing method of the present invention can save the process of laminating pure glue and polyimide, as well as the process of manually removing the pure glue after opening the cover; at the same time, because manual labor is reduced, the manufacturing method of the present invention can effectively shorten the processing time of the product and reduce production costs; in addition, because the manufacturing method of the present invention reduces the opportunity for direct manual contact with the board surface, it can also ensure the integrity and processing accuracy of the opening position, reducing the quality risks such as scratches, bends, cracks, and residual glue during the process.

[0058] In this embodiment, the steps of manufacturing the flexible layer 1 specifically include:

[0059] Cut the flexible board substrate into pieces and cut them into pieces according to the design requirements to obtain the flexible substrate of the designed size;

[0060] The flexible layer circuit is manufactured on the flexible substrate through the processes of drilling, laminating, exposing, developing, etching and stripping;

[0061] Perform AOI (Automated Optical Inspection) inspection on the inner layer of the flexible substrate after the inner layer circuit is completed;

[0062] The surface of the flexible substrate that has passed the AOI inspection is cleaned and then subjected to a browning treatment; the browning treatment is to increase the surface roughness to improve its adhesion;

[0063] A cover film is attached to the surface of the flexible substrate and a window is opened; wherein the window is opened to expose a portion of the copper layer on the flexible substrate;

[0064] The flexible substrate is subjected to heat pressing treatment to make the cover film and the flexible substrate tightly bonded together.

[0065] The flexible substrate is punched with an OPE punching machine and then browned again to complete the production of the flexible layer 1.

[0066] It should be noted that each step of manufacturing the flexible layer 1 can refer to the prior art and will not be described in detail here.

[0067] It should also be noted that multiple design units will be produced simultaneously on the same flexible substrate, and each design unit constitutes a flexible layer 1 of a rigid-flexible circuit board; each flexible layer 1 includes a rigid area 12 and a flexible area 11, wherein the rigid area 12 refers to the area in the flexible layer 1 that overlaps and is pressed with the rigid layer 3, and the flexible area 11 refers to the area connecting two adjacent rigid areas 12.

[0068] In this embodiment, the steps of making the prepreg 2 include:

[0069] A positioning hole 21 is provided on the prepreg 2;

[0070] The prepreg 2 is positioned through the positioning holes 21, and a circuit layout area 23 is divided on the prepreg 2. The circuit layout area 23 includes a plurality of circuit layout unit areas 24.

[0071] A hollowing process is performed on at least a portion of the prepreg 2 in the circuit arrangement unit area 24 to form a pre-hollowing area 22 .

[0072] Specifically, refer to Figure 2 As shown, a plurality of positioning holes 21 are pre-opened on the prepreg 2 so as to position the prepreg 2 through the positioning holes 21 .

[0073] After positioning and fixing the prepreg 2, refer to Figure 3 As shown, a circuit layout area 23 is divided on the prepreg 2, and the circuit layout area 23 corresponds to the area where the flexible layer circuit is arranged on the flexible substrate; then a number of circuit layout unit areas 24 are divided on the circuit layout area 23; each circuit layout unit area 24 corresponds one-to-one to a design unit on the aforementioned flexible substrate.

[0074] The positions corresponding to the flexible areas 11 on each circuit arrangement unit area 24 are then hollowed out to complete the production of the prepreg 2. Hollowing out refers to completely removing the material in that area. In this embodiment, hollowing out the prepreg means that the area of ​​the prepreg is penetrated.

[0075] In this embodiment, the positioning holes 21 are provided on the prepreg 2 , and the prepreg is positioned by the positioning holes 21 , so that the pre-hollowed area 22 can be positioned better.

[0076] In this embodiment, reference Figure 2 and Figure 3 As shown, the circuit arrangement area 23 is a rectangular area, the positioning holes 21 are multiple, and the multiple positioning holes 21 are arranged around the periphery of the circuit arrangement area 23. Of course, in some other examples, the circuit arrangement area 23 includes but is not limited to Figure 2 The rectangular area shown may also be a polygonal area or an irregular area, for example.

[0077] In this embodiment, by arranging various positioning holes 21 on the periphery of the circuit layout area 23, the positioning points on the flexible layer 1 described below can be avoided from the circuits on the flexible layer 1, thereby facilitating the arrangement of the positioning points on the flexible layer 1; at the same time, by arranging the positioning holes 21 around the periphery of the circuit layout area 23, the position of the semi-cured sheet 2 in various directions can be positioned, which can improve the positioning accuracy of the semi-cured sheet 2, that is, the positioning accuracy of the pre-hollowed area 22 can be improved.

[0078] In this embodiment, the prepreg 2 preferably comprises a low-flow prepreg 2. By using a low-flow prepreg 2, the prepreg 2 can be prevented from affecting the surface of the flexible area 11 due to the flow of the prepreg 2 during the lamination process between the prepreg 2 and the flexible layer. It should be noted that the prepreg 2 may also be a non-flow prepreg or a medium-flow prepreg.

[0079] In this embodiment, the step of fixing and connecting the prepreg 2 and the flexible layer 1 specifically includes:

[0080] Align the positioning point of the flexible layer 1 with the positioning hole 21 of the prepreg 2;

[0081] The flexible layer 1 and the prepreg 2 are fixedly connected after being matched; wherein the flexible area 11 of the flexible layer 1 corresponds to the pre-hollowed area 22 .

[0082] In this embodiment, the positioning points of the flexible layer 1 may be, for example, positioning holes provided on the flexible substrate, and the flexible layer 1 and the prepreg 2 are preferably fixedly connected by riveting.

[0083] By fixing the flexible layer 1 and the prepreg 2 by riveting in advance and then processing the rigid layer, the flexible layer 1 and the prepreg 2 can be prevented from being misaligned in subsequent processing, so that the following opening position is more accurate.

[0084] In this embodiment, the steps of making the rigid layer 3 specifically include:

[0085] relative to the first surface of the prepreg 2 to which the flexible layer 1 is fixed, and laminating a copper foil on a second surface of the prepreg 2 opposite to the first surface;

[0086] The inner layer circuit of the rigid layer 3 is manufactured on the copper foil, wherein the process of manufacturing the inner layer circuit of the rigid layer 3 on the copper foil includes lamination, exposure, development, etching and stripping.

[0087] Among them, lamination is to stick a layer of photosensitive dry film on the surface of copper foil;

[0088] Exposure is to align the film with the substrate with the pressed photosensitive film, and use ultraviolet light on the exposure machine to transfer the film pattern to the photosensitive dry film;

[0089] Development is the process of using a developer to dissolve and wash away the unexposed dry film, while retaining the exposed part.

[0090] Etching is to dissolve and corrode the copper surface exposed in the development step to obtain the required circuit;

[0091] The film stripping method peels off the exposed dry film that protects the copper surface to reveal the circuit pattern.

[0092] After the inner circuit of the rigid layer 3 is completed, the drilling, copper deposition, electroplating, outer circuit, solder mask and surface treatment processes are carried out in sequence to complete the production of the rigid-flexible circuit board. It should be noted that the steps of making the rigid layer can refer to the existing technology and will not be described in detail here.

[0093] In this embodiment, the step of forming the open cover area 31 on the rigid layer 3 includes:

[0094] Performing a decapping process on the side of the rigid layer 3 away from the prepreg 2;

[0095] The pre-hollowed area 22 and the flexible area 11 covered by the rigid layer 3 are exposed to form the above-mentioned open cover area 31.

[0096] In this embodiment, the specific method of opening the cover is to perform controlled depth milling on the rigid layer 3 to remove the rigid layer 3 covering the pre-hollowed area 22 on the semi-cured sheet 2, thereby exposing the pre-hollowed area 22 on the semi-cured sheet 2 and the flexible area 11 of the flexible layer 1.

[0097] In this embodiment, after the step of forming the opening area 31 on the rigid layer 3 , the residual glue around the opening area 31 is removed.

[0098] By fine-tuning the cover opening area 31 and removing residual glue around the cover opening area, the quality of the product can be improved and residual glue residue can be avoided.

[0099] In this embodiment, the specific method for removing the residual glue around the cover opening area 31 is to use laser cutting to remove the residual glue around the cover opening area 31. The residual glue around the cover opening area 31 specifically refers to the glue remaining on the sidewall of the area where the rigid layer 3 is milled away. The laser cutting can specifically be UV laser cutting or CO2 laser cutting.

[0100] In summary, the method for manufacturing a rigid-flexible circuit board in this embodiment is to pre-process a pre-hollowed area 22 corresponding to the flexible area 11 on the semi-cured sheet; after the semi-cured sheet 2 and the flexible layer are laminated and processed to the outer layer in sequence, the rigid layer covering the pre-hollowed area 22 is removed to directly expose the flexible area 11, thereby simplifying the manufacturing process of the rigid-flexible circuit board.

[0101] Example 2

[0102] Based on the above-mentioned embodiment 1, embodiment 2 of the present invention provides a rigid-flex circuit board.

[0103] refer to Figure 4 As shown, the rigid-flex circuit board includes a flexible layer 1, a prepreg 2 and a rigid layer 3.

[0104] The flexible layer 1 and the rigid layer 3 are respectively located on the surfaces of the prepreg 2 on opposite sides. The flexible layer 1 has a flexible area 11 , the prepreg 2 has a pre-hollowed area 22 ; the rigid layer 3 has an open cover area 31 .

[0105] The flexible area 11 , the pre-scooped area 22 and the lid opening area 31 are all corresponding to each other; the lid opening area 31 is connected to the pre-scooped area 22 and exposes the flexible area 11 .

[0106] The rigid-flexible circuit board of the present invention provides a pre-hollowed area 22 on the prepreg 2. After the flexible layer 1, the prepreg 2 and the rigid layer 3 are stacked and pressed together, an opening area 31 can be processed on the rigid layer to directly expose the flexible area 11, thereby enabling the rigid-flexible circuit board to have a lower processing cost.

[0107] In the description of the embodiments of the present invention, it should be understood that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The orientations or positional relationships indicated by the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise precisely and specifically specified.

[0108] The terms "first," "second," "third," "fourth," and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential sequence. It should be understood that the numbers used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or that are inherent to these processes, methods, products, or apparatus.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a rigid-flex circuit board, characterized in that: The following steps are involved: making a flexible layer and forming a flexible area on the flexible layer; Making a prepreg and forming a pre-scooped area on the prepreg; The flexible layer is fixedly connected to the first surface of the prepreg, and the pre-hollowed area corresponds to the flexible area; forming a rigid layer on the second surface of the prepreg, wherein the first surface and the second surface are two opposite surfaces of the prepreg; By performing controlled depth milling on the rigid layer, a cover opening area is formed on the rigid layer; wherein the cover opening area corresponds to the pre-scooped area and the flexible area, the cover opening area is connected to the pre-scooped area, and the flexible area is exposed; The method of making a prepreg comprises: forming positioning holes on the prepreg, the positioning holes being used to position the prepreg; dividing the prepreg into circuit layout areas, the circuit layout areas including a plurality of circuit layout unit areas; hollowing out the prepreg in at least a portion of the circuit layout unit areas to form the pre-hollowed-out areas; The fixed connection between the prepreg and the flexible layer includes: aligning the positioning points on the flexible layer with the positioning holes of the prepreg; and fixedly connecting the aligned flexible layer and the prepreg; wherein the flexible area of ​​the flexible layer corresponds to the pre-hollowed area.

2. The method for manufacturing a rigid-flex circuit board according to claim 1, wherein: After forming the cover-opening area on the rigid layer, the method further comprises: Remove the residual glue around the opening area.

3. The method for manufacturing a rigid-flex circuit board according to claim 2, wherein: The step of removing the residual glue around the cover opening area includes: Laser cutting is used to remove the residual glue around the opening area.

4. The method for manufacturing a rigid-flex circuit board according to claim 1, wherein: The manufacturing of the flexible layer comprises: Cutting the soft board substrate to obtain a flexible substrate; The flexible layer circuit is manufactured on the flexible substrate through the processes of drilling, laminating, exposing, developing, etching and stripping; Automated optical inspection of flexible substrates; Browning treatment; A cover film is attached to the surface of the flexible layer and windows are opened.

5. The method for manufacturing a rigid-flex circuit board according to claim 1, wherein: The step of forming the cover-opening area on the rigid layer includes: performing a decapping process on a side of the rigid layer away from the prepreg; The pre-hollowed area and the flexible area covered by the rigid layer are exposed, and the cover-opening area is formed.

6. The method for manufacturing a rigid-flex circuit board according to claim 1, wherein: The circuit arrangement area is a rectangular area, and there are a plurality of positioning holes, which are spaced apart around the periphery of the circuit arrangement area.

7. The method for manufacturing a rigid-flexible circuit board according to any one of claims 1 to 6, characterized in that: The prepreg comprises a low-flow prepreg.

8. A rigid-flex circuit board, characterized in that: The method for manufacturing a rigid-flexible circuit board according to any one of claims 1 to 7 is used to prepare the rigid-flexible circuit board, wherein the rigid-flexible circuit board comprises a flexible layer, a prepreg, and a rigid layer; The flexible layer and the rigid layer are respectively located on the surfaces of the prepreg on opposite sides, the flexible layer has a flexible area, the prepreg has a pre-hollowed area, and the rigid layer has an open cover area; The flexible area, the pre-scooping area and the lid opening area all correspond; The cover opening area is communicated with the pre-scooping area and exposes the flexible area.

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