A rigid-flex printed circuit board manufacturing method and a rigid-flex printed circuit board

Abstract

The application provides a rigid-flexible combination plate manufacturing method and a rigid-flexible combination plate. The rigid-flexible combination plate comprises two rigid plates, a plurality of flexible plates, an outer adhesive layer between the rigid plates and the flexible plates, and an inner adhesive layer between every two flexible plates. The method comprises the following steps: S1, flexible plate processing; S2, adhesive layer processing: respectively reserving rigid areas and flexible window areas of the outer adhesive layer and the inner adhesive layer; S3, pressing: pressing and fusing the reserved rigid areas and the flexible window areas of the outer adhesive layer and the inner adhesive layer; and S4, uncovering: milling off the rigid areas and the flexible window areas of the outer adhesive layer and the inner adhesive layer respectively or together to expose the flexible areas. After uncovering, the flexible layer part waste fused after pressing is removed together with the upper rigid waste area, so that the defects of cracking and pressing are effectively avoided, and the processing quality of the plate part is effectively ensured.

Description

Technical Field

[0001] The present invention relates to a PCB processing technology, and in particular to a method for manufacturing a rigid-flexible board. Background Art

[0002] A rigid-flex circuit board (R-Flex) is a circuit board that combines thin flexible layers with rigid layers. This means a single printed circuit board contains one or more rigid and flexible areas, laminated together in an orderly fashion. The circuits on the rigid and flexible printed circuit board layers are electrically interconnected through drilling, plated-through holes, and lamination processes. Rigid-flex boards combine the bendability and flexibility of flexible boards with the solderability of rigid boards. They offer flexibility and foldability, transcending traditional flat-panel design concepts to encompass three-dimensional space. By bending and folding circuits, they optimize space, confining the design scope to a single component. This provides ample room for imagination and creativity in the design of all electrical components and electronic devices. Furthermore, because rigid-flex boards incorporate both rigid and flexible layers, they improve connection reliability while reducing weight and overall size, resulting in widespread application in many fields.

[0003] However, with the continuous refinement of rigid-flex PCB design, there are laminated structures in which although rigid-flex PCB is also composed of multiple layers of flexible boards, the outer design area of ​​each inner layer of flexible boards is different. Some inner layer flexible boards also have structural designs such as text and fingers. This results in only a small part of some inner layer flexible layers being retained, and the areas where the lines are led out of each inner layer flexible layer are different, eventually forming a complex traffic network similar to a multi-layer viaduct, and the inner layer flexible layers also need to expose the pads and text processing. This complex rigid-flex PCB structure, in the current manufacturing method, such as Figure 1 As shown, taking the second layer of flexible board as an example, one method is to completely remove the waste area 1' of the flexible board before pre-stacking, and remove the adhesive layer (PP) in the non-rigid area, that is, only retain the adhesive layer (PP) in the rigid area 2', and hollow out other positions. This manufacturing process will cause many abnormal processing defects such as embossing on the inner layer and cracking on the outer layer after lamination; another manufacturing method, such as Figure 2 As shown, taking the second layer of flexible board as an example, before pre-stacking, for the waste area of ​​the flexible board, only a laser groove 3' is formed in the rigid-flexible bonding area, and the adhesive layer (PP) is removed in the non-rigid area, leaving only the adhesive layer in the rigid area 2'. After the board is completed, the waste is extracted after molding. This manufacturing process will make it difficult to extract the waste, and the extraction process will easily lead to technical problems such as scrapping of the board.

[0004] Therefore, for the laminated structure with different outer design areas of the inner flexible board, the existing rigid-flexible board manufacturing process has insurmountable technical problems and technical defects, and the existing production and preparation process cannot guarantee effective and reliable production. Summary of the Invention

[0005] An embodiment of the present invention provides a method for manufacturing a rigid-flexible board and a rigid-flexible board thereof. By optimizing the preparation process, the waste material of the flexible layer that is integrated after pressing is removed together with the upper rigid waste area after opening the cover, without the need to extract the waste material, effectively avoiding cracking and stamping defects, saving board processing time, and effectively ensuring the processing quality of the board through process improvement.

[0006] The technical solution adopted by at least one embodiment of the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for manufacturing a rigid-flexible board, the rigid-flexible board comprising two rigid boards, a plurality of flexible boards, an outer bonding layer between the rigid boards and the flexible boards, and an inner bonding layer between each two flexible boards. The method for manufacturing the rigid-flexible board comprises the following steps:

[0008] S1. Flexible board processing:

[0009] Producing circuit patterns on each flexible board and processing the shape of the flexible circuit area to isolate the flexible circuit area from the surrounding waste area;

[0010] S2. Adhesive layer treatment:

[0011] Retaining the rigid area and the flexible window area of ​​the outer bonding layer and the inner bonding layer respectively;

[0012] S3, pressing:

[0013] The rigid plate, the outer bonding layer, the plurality of flexible plates and the inner bonding layer are stacked and pressed together so that the retained rigid areas and the flexible window areas of the outer bonding layer and the inner bonding layer are pressed together and integrated;

[0014] After the lamination step, the circuit board is drilled, hole metallized and outer layer circuits are produced according to conventional methods;

[0015] S4. Open the cover:

[0016] Milling off the rigid areas and flexible window areas of the corresponding outer and inner bonding layers of the flexible plate separately or together, removing the ineffective areas on each rigid plate and the waste areas on each flexible plate, and exposing the flexible areas;

[0017] After the decapping step, a post-production process is performed to obtain the rigid-flexible board;

[0018] The two rigid plates have the same size, the flexible plates have different sizes and structures from the two rigid plates, and the size and structure of each layer of flexible plate are different from those of the adjacent layer of flexible plate, and the area of each layer of flexible plate for leading out the circuit is different.

[0019] Further, the number of layers of the flexible plates is 2-20.

[0020] Further, before the step of pressing the plurality of flexible plates between the two rigid plates by the pressing method, the method further comprises:

[0021] Making the inner rigid circuit pattern on the effective area of at least one rigid plate and / or the outer rigid circuit pattern.

[0022] Further, after the step of pressing the plurality of flexible plates between the two rigid plates by the pressing method, the method further comprises:

[0023] Making the outer rigid circuit pattern on the effective area of at least one rigid plate.

[0024] Further, the rigid-flexible combination plate comprises a first rigid plate, a first outer adhesive layer, a plurality of layers of flexible plates, an inner adhesive layer between each two layers of flexible plates, a second outer adhesive layer and a second rigid plate which are sequentially stacked, and the rigid-flexible combination plate manufacturing method comprises the following steps:

[0025] S1, flexible plate processing:

[0026] Making a circuit pattern on each flexible plate respectively, and processing the shape of the flexible circuit area to isolate the flexible circuit area and the peripheral waste area;

[0027] S2, adhesive layer processing:

[0028] Respectively retaining the rigid area and the flexible window area of the first outer adhesive layer, the inner adhesive layer and the second outer adhesive layer;

[0029] S3, pressing:

[0030] Stacking the first rigid plate, the first outer adhesive layer, the plurality of layers of flexible plates, the inner adhesive layer between each two layers of flexible plates, the second outer adhesive layer and the second rigid plate in sequence, and pressing, so that the rigid area and the flexible window area of the first outer adhesive layer, the second outer adhesive layer and the inner adhesive layer are fused into one after pressing;

[0031] The circuit board after the pressing step is drilled, hole metallized and outer circuit made according to the conventional method;

[0032] S4, uncovering:

[0033] Milling off the rigid areas and flexible window areas of the flexible plate corresponding to the first outer bonding layer, the inner bonding layer, and the second outer bonding layer, respectively or together, removing the ineffective area on each rigid plate and the waste area on each flexible plate to expose the flexible area;

[0034] After the decapping step, a post-production process is performed to obtain the rigid-flexible board.

[0035] In a second aspect, the present invention provides a rigid-flexible board, which is manufactured using the rigid-flexible board manufacturing method described above.

[0036] Advantages of the present invention:

[0037] In order to solve the problems of inconsistent dimensions and structures between flexible boards and rigid boards, inconsistent dimensions and structures between adjacent laminated flexible boards, and different circuit leading areas of each layer of flexible boards, the existing rigid-flexible board preparation technology either requires the waste area of ​​the flexible board to be completely removed before pre-stacking, and the adhesive layer to be removed in the non-rigid area, resulting in many abnormal processing defects such as embossing in the inner layer and cracking in the outer layer after lamination; or, before pre-stacking, only a single laser groove is cut in the rigid-flexible bonding area of ​​the flexible board, and the adhesive layer is removed in the non-rigid area. After the board is completed, the waste is extracted after forming, resulting in technical problems such as difficulty in extracting the waste and the extraction process easily leading to scrapping of the board.

[0038] The present invention optimizes the preparation process. During the bonding layer processing, the rigid areas and flexible window areas of the outer bonding layer and the inner bonding layer are respectively retained. During pressing, the retained rigid areas and flexible window areas of the outer bonding layer and the inner bonding layer are pressed and fused together. After the cover is opened, the waste material of the flexible layer that is fused together after pressing is removed together with the upper rigid waste area, thereby eliminating the subsequent waste extraction process steps, effectively avoiding fractures and embossing defects, saving plate processing time, and effectively ensuring the processing quality of the plate through process improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of a structure in which the waste area of ​​the flexible board before pre-stacking is completely removed in the prior art;

[0040] Figure 2 A schematic diagram of the structure of slotting the rigid-flexible bonding area of ​​a flexible board before pre-stacking in the prior art;

[0041] Figure 3 Schematic diagram of the enlarged structure of the rigid-flex board in the present invention;

[0042] Figure 4 Schematic diagram of the enlarged structure of the second flexible board of the rigid-flex board in the present invention;

[0043] Figure 5 It is an enlarged schematic diagram of the sequential stacking structure of each layer of rigid plates and flexible plates in the present invention;

[0044] Figure 6 This is an enlarged schematic diagram of the finished product after the layers of the rigid-flex board in the present invention are combined. DETAILED DESCRIPTION

[0045] In order to make the technical solution of the present invention more clearly understood by those skilled in the art, the following examples are given for illustration. It should be noted that the following examples do not limit the scope of protection claimed by the present invention.

[0046] A method for manufacturing a rigid-flexible board, such as Figures 3 to 6 As shown, the rigid-flexible board includes a first rigid board 1, a first outer bonding layer 2, a plurality of flexible boards 3, an inner bonding layer 4, a second outer bonding layer 5, and a second rigid board 6 stacked in sequence. The method for manufacturing the rigid-flexible board includes the following steps:

[0047] S1, flexible board 3 processing:

[0048] A circuit pattern is made on each flexible board 3, and the shape of the flexible circuit area is processed to isolate the flexible circuit area from the surrounding waste area;

[0049] S2. Adhesive layer treatment:

[0050] Retain the rigid area 20 and the flexible window area 21 of the first outer bonding layer 2, the inner bonding layer 4 and the second outer bonding layer 5 respectively;

[0051] S3, pressing:

[0052] The first rigid plate 1, the first outer bonding layer 2, the multiple layers of flexible plates 3, the inner bonding layer 4 between each two layers of flexible plates 3, the second outer bonding layer 5, and the second rigid plate 6 are sequentially stacked and pressed together so that the rigid areas and the flexible window areas of the first outer bonding layer 2, the second outer bonding layer 5, and the inner bonding layer 4 are pressed together and integrated.

[0053] After the lamination step, the circuit board is drilled, hole metallized and outer layer circuits are produced according to the conventional method;

[0054] S4. Open the cover:

[0055] Mill off the rigid areas and flexible window areas of the first outer bonding layer 2, inner bonding layer 4, and second outer bonding layer 5 of the flexible plate 3, respectively or together, remove the ineffective areas on each rigid plate and the waste areas on each flexible plate 3, and expose the flexible areas;

[0056] After the cover opening step, the post-processing is carried out to obtain the rigid-flexible board.

[0057] Among them, the sizes of the first rigid board 1 and the second rigid board 6 are consistent, the sizes and structures of the multiple flexible boards 3 are inconsistent with the sizes and structures of the first rigid board 1 and the second rigid board 6, and the external dimensions and structure of each layer of flexible boards 3 are inconsistent with the external dimensions and structure of the flexible boards 3 of the adjacent stacked layers, and the areas where the circuits are led out of each layer of flexible boards 3 are different.

[0058] In the lamination of step S3, before the step of laminating the plurality of flexible boards 3 between the first rigid board 1 and the second rigid board 6 by lamination, the method further includes: producing an inner layer rigid circuit pattern and / or an outer layer rigid circuit pattern on the effective area of ​​at least one rigid board. And after the step of laminating the plurality of flexible boards 3 between the first rigid board 1 and the second rigid board 6 by lamination, the method further includes: producing an outer layer rigid circuit pattern on the effective area of ​​at least one rigid board. In this embodiment, the flexible board 3 and the rigid board are pressed together by lamination. Since the rigid-flexible board is a multi-layer substrate, the first rigid board 1 and the second rigid board 6 may have, but are not limited to, an inner layer rigid circuit pattern, an outer layer rigid circuit pattern, and / or no rigid circuit pattern. It can be seen that the rigid circuit pattern of the rigid-flexible board can be designed according to the actual needs of the user, and a single-sided rigid circuit pattern, a double-sided rigid circuit pattern, or no circuit pattern at all can be produced on the rigid board.

[0059] In this example, when processing the bonding layer, the rigid areas and flexible window areas of the first outer bonding layer 2, the second outer bonding layer 5 and the inner bonding layer 4 are retained respectively. When pressing, the retained rigid areas and flexible window areas of the first outer bonding layer, the second outer bonding layer 5 and the inner bonding layer 4 are pressed and fused together. After opening the cover, the waste of the flexible layer that is fused together after pressing is removed together with the upper rigid waste area, eliminating the subsequent waste extraction process steps, effectively avoiding cracking and embossing defects, saving plate processing time, and effectively ensuring the processing quality of the plate through process improvement.

[0060] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Except for the cases listed in the specific embodiments, all equivalent changes made according to the methods and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for manufacturing a rigid-flexible board, the rigid-flexible board comprising two rigid boards, a plurality of flexible boards, an outer bonding layer between the rigid boards and the flexible boards, and an inner bonding layer between each two flexible boards, characterized in that: The method for manufacturing a rigid-flexible board comprises the following steps: S1. Flexible board processing: Producing circuit patterns on each flexible board and processing the shape of the flexible circuit area to isolate the flexible circuit area from the surrounding waste area; S2. Adhesive layer treatment: Retaining the rigid area and the flexible window area of ​​the outer bonding layer and the inner bonding layer respectively; S3, pressing: The rigid plate, the outer bonding layer, the plurality of flexible plates and the inner bonding layer are stacked and pressed together so that the retained rigid areas and the flexible window areas of the outer bonding layer and the inner bonding layer are pressed together and integrated; After the lamination step, the circuit board is drilled, hole metallized and outer layer circuits are produced according to conventional methods; S4. Open the cover: Milling off the rigid areas and flexible window areas of the corresponding outer and inner bonding layers of the flexible plate separately or together, removing the ineffective areas on each rigid plate and the waste areas on each flexible plate, and exposing the flexible areas; After the decapping step, a post-production process is performed to obtain the rigid-flexible board; The two rigid boards have the same size, the size and structure of the multiple flexible boards are inconsistent with the size and structure of the two rigid boards, the outer dimensions and structure of each layer of flexible boards are inconsistent with the outer dimensions and structure of the flexible boards of the adjacent layers, and the areas where the circuits are led out of each layer of flexible boards are different.

2. The method for manufacturing a rigid-flex board according to claim 1, wherein: The number of layers of the flexible board is 2-20.

3. The method for manufacturing a rigid-flexible board according to claim 1, wherein: Before the step of pressing the plurality of flexible plates between the two rigid plates by the pressing method, the method further includes: An inner layer rigid circuit pattern and / or an outer layer rigid circuit pattern are manufactured on an effective area of ​​at least one rigid board.

4. The method for manufacturing a rigid-flexible board according to claim 1, wherein: After the step of pressing the plurality of flexible plates between the two rigid plates by the pressing method, the method further includes: An outer layer of rigid circuit patterns is formed on an effective area of ​​at least one rigid board.

5. A rigid-flex board, characterized in that: The rigid-flex board is manufactured by the rigid-flex board manufacturing method according to any one of claims 1 to 4.

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