Method for manufacturing flexible circuit board

Abstract

A method for manufacturing a flexible circuit board includes: providing two copper-clad plates and an adhesive layer, bonding the two copper-clad plates together through the adhesive layer to obtain an intermediate; forming two circuit layers on the two surfaces of the intermediate to obtain a first flexible circuit board and a second flexible circuit board; and then rolling the first flexible circuit board and the second flexible circuit board pasted on the adhesive layer. The method for manufacturing a flexible circuit board provided by the present invention adopts a roll-to-roll lamination production method, and can simultaneously produce two single-layer or multi-layer flexible circuit boards. On the basis of streamlining the process, it effectively improves production efficiency and capacity, while saving materials and reducing costs.

Description

Technical Field

[0001] The invention relates to a printed circuit board technology, and in particular to a method for manufacturing a flexible circuit board. Background Art

[0002] The conventional method for manufacturing a multi-layer flexible circuit board is to first manufacture each single-layer flexible circuit board separately, and then press the separately manufactured single-layer flexible circuit boards together to manufacture subsequent multi-layer boards.

[0003] However, the production cycle of multiple single-layer flexible circuit boards is long, the efficiency is low, the consumables are large, and the cost is high. Summary of the invention

[0004] In view of the above, it is necessary to propose a method for manufacturing a flexible circuit board with simple process, high manufacturing efficiency and low cost.

[0005] The present invention provides a method for manufacturing a flexible circuit board, comprising the following steps:

[0006] A first copper clad laminate and a second copper clad laminate are provided. The first copper clad laminate includes a first metal layer and a second metal layer that are oppositely arranged. The second copper clad laminate includes a third metal layer and a fourth metal layer that are oppositely arranged.

[0007] An adhesive layer is provided, and the first copper clad laminate, the adhesive layer and the second copper clad laminate are stacked in sequence so that the adhesive layer is located between the second metal layer and the third metal layer, and then bonded to obtain a first intermediate.

[0008] A first circuit layer is formed on the first metal layer at the outermost side of the first intermediate body, and the first circuit layer is electrically connected to the second metal layer to form a first flexible circuit board. A second circuit layer is formed on the fourth metal layer at the outermost side of the intermediate body, and the second circuit layer is electrically connected to the third metal layer to form a second flexible circuit board.

[0009] And, the first flexible circuit board and the second flexible circuit board on the adhesive layer are rolled up.

[0010] In the implementation manner of the present application, the method for manufacturing the flexible circuit board further includes:

[0011] A first blind hole and a second blind hole are respectively formed on two sides of the intermediate body.

[0012] And, a first conductive layer is formed in the first blind hole to electrically connect the first circuit layer with the second metal layer, and a second conductive layer is formed in the second blind hole to electrically connect the second circuit layer with the third metal layer.

[0013] In the embodiment of the present application, before the first flexible circuit board and the second flexible circuit board on the adhesive layer are rolled up, the method further includes:

[0014] A layer is added on the surface of the first circuit layer to form at least one third circuit layer, and the third circuit layer is electrically connected to the first circuit layer.

[0015] Furthermore, a layer is added on the surface of the second circuit layer to form at least one fourth circuit layer, and the fourth circuit layer is electrically connected to the second circuit layer.

[0016] In the implementation manner of the present application, the method for manufacturing the flexible circuit board further includes:

[0017] The first intermediate is trimmed.

[0018] In the embodiment of the present application, before the first flexible circuit board and the second flexible circuit board on the adhesive layer are rolled up, the method further includes:

[0019] A plurality of through holes or third blind holes are formed on the first flexible circuit board and the second flexible circuit board to form an identification code.

[0020] In the embodiment of the present application, the step of rolling up the first flexible circuit board and the second flexible circuit board on the adhesive layer specifically includes:

[0021] A reeling device is provided, the reeling device includes a reeling wheel group and a reeling wheel group, the reeling wheel group includes a first reeling wheel group and a second reeling wheel group arranged opposite to each other, the reeling wheel group is used to reel the first flexible circuit board and the second flexible circuit board, and the reeling wheel group is used to reel the first flexible circuit board and the second flexible circuit board after reeling.

[0022] The first flexible circuit board and the second flexible circuit board attached to the adhesive layer are passed between the first sub-rolling wheel group and the second sub-rolling wheel group, and the first flexible circuit board and the second flexible circuit board are respectively in contact with the first sub-rolling wheel group and the second sub-rolling wheel group.

[0023] The first winding wheel group and the second winding wheel group respectively wind up the first flexible circuit board and the second flexible circuit board.

[0024] Furthermore, the winding wheel group respectively winds up the first flexible circuit board and the second flexible circuit board after being rolled up.

[0025] In an embodiment of the present application, the reeling device further includes a separation mechanism, and the separation mechanism is used to separate the first flexible circuit board and the second flexible circuit board on the second intermediate body from the adhesive layer.

[0026] In the implementation manner of the present application, the separation mechanism is arranged on a side of the winding wheel group close to the reeling wheel group, and the separation mechanism includes two separation knives respectively arranged corresponding to the first winding wheel group and the second winding wheel group.

[0027] In an embodiment of the present application, the separation mechanism is arranged on a side of the winding wheel group away from the winding wheel group, and the separation mechanism includes a separation groove and a separation liquid contained in the separation groove, and the separation liquid is used to reduce the viscosity of the adhesive layer so as to separate the adhesive layer from the first flexible circuit board and the second flexible circuit board.

[0028] In an embodiment of the present application, the winding device further comprises a cleaning and drying mechanism disposed on a side of the winding wheel group away from the winding wheel group, and the cleaning and drying mechanism is used to clean and dry the first flexible circuit board and the second flexible circuit board after winding.

[0029] Compared with the prior art, the manufacturing method of the flexible circuit board provided by the present invention adopts a roll-to-roll lamination production method, which can simultaneously produce two single-layer or multi-layer flexible circuit boards. On the basis of streamlining the process, it effectively improves production efficiency and increases production capacity, while saving materials and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic structural diagram of a first copper clad laminate, a second copper clad laminate, and an adhesive layer provided in one embodiment of the present invention.

[0031] Figure 2 A schematic structural diagram of a first intermediate provided in one embodiment of the present invention.

[0032] Figure 3 A schematic structural diagram of a second intermediate provided in one embodiment of the present invention.

[0033] Figure 4 A schematic structural diagram of an adhesive layer is provided for one embodiment of the present invention.

[0034] Figure 5 A flowchart of a manufacturing process of a flexible circuit board provided in accordance with an embodiment of the present invention.

[0035] Figure 6 A comparison diagram of two identification codes provided in one embodiment of the present invention.

[0036] Figure 7 A volume splitting flow chart provided for an embodiment of the present invention.

[0037] Figure 8 A volume splitting flow chart provided for another embodiment of the present invention.

[0038] Fig. 9 A volume splitting flow chart provided for another embodiment of the present invention.

[0039] Main component symbols

[0040] First flexible circuit board 100

[0041] Intermediate 10

[0042] Second intermediate 20

[0043] First copper clad laminate 1

[0044] The first intermediate layer 11

[0045] The first metal layer 12

[0046] The second metal layer 13

[0047] The first circuit layer 14

[0048] First blind hole 15

[0049] The first conductive layer 16

[0050] Second flexible circuit board 200

[0051] Second copper clad laminate 2

[0052] Second intermediate layer 21

[0053] The third metal layer 22

[0054] Fourth metal layer 23

[0055] The second circuit layer 24

[0056] Second blind hole 25

[0057] The second conductive layer 26

[0058] Adhesive layer 3

[0059] Substrate 31

[0060] First adhesive layer 32

[0061] Second adhesive layer 33

[0062] Release film 4

[0063] Rolling device 300

[0064] Reel Group 5

[0065] The first winding wheel group 51

[0066] Second winding wheel group 52

[0067] Winding wheel set 6

[0068] The first winding wheel 61

[0069] Second winding wheel 62

[0070] The third winding wheel 63

[0071] Separation mechanism7,8

[0072] Separation tank 81

[0073] Separation liquid 82

[0074] Cleaning and drying mechanism 9

[0075] Through hole

[0076] The third blind hole b

[0077] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0078] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0079] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0080] See also Figure 5 , a method for manufacturing a flexible circuit board provided by an embodiment of the present invention, the method specifically comprises the following steps:

[0081] S1, in conjunction with reference Figure 1 A first copper clad laminate 1 and a second copper clad laminate 2 are provided, wherein the first copper clad laminate 1 comprises a first intermediate layer 11 and a first metal layer 12 and a second metal layer 13 disposed on opposite surfaces of the first intermediate layer 11. The second copper clad laminate 2 comprises a second intermediate layer 21 and a third metal layer 22 and a fourth metal layer 23 disposed on opposite surfaces of the second intermediate layer 21.

[0082] In one embodiment, the first copper clad laminate 1 and the second copper clad laminate 2 may be double-sided copper clad laminates, the first intermediate layer 11 and the second intermediate layer 21 may be an insulating layer, the first intermediate layer 11 and the second intermediate layer 21 may be made of polyimide, and the first metal layer 12, the second metal layer 13, the third metal layer 22 and the fourth metal layer 23 may be copper foil layers.

[0083] In another embodiment, the first copper clad laminate 1 and the second copper clad laminate 2 may be multi-layer soft boards, and the first intermediate layer 11 and the second intermediate layer 21 may include multiple inner circuit layers.

[0084] S2, combined with reference Figure 1 and Figure 2 , providing an adhesive layer 3, stacking the first copper clad laminate 1, the adhesive layer 3 and the second copper clad laminate 2 in sequence so that the adhesive layer 3 is located between the second metal layer 13 and the third metal layer 22, and then pressing to obtain a first intermediate 10.

[0085] In one embodiment, the adhesive layer 3 is a double-sided tape, specifically including a substrate 31 and a first adhesive layer 32 and a second adhesive layer 33 arranged on two opposite surfaces of the substrate 31, wherein the first adhesive layer 32 is bonded to the second metal layer 13, and the second adhesive layer 33 is bonded to the third metal layer 22.

[0086] In the present application, an adhesive layer 3 is used to bond two copper-clad laminates together. The adhesive layer 3 is required to have a certain load-bearing capacity. Moreover, in the process of producing flexible circuit boards, acidic and alkaline solutions and a high-temperature environment are required. Therefore, the selected substrate 31 needs to have a certain stiffness and needs to be resistant to acid and alkali corrosion and high temperature.

[0087] In one embodiment, the substrate 31 may be a plastic film, and specifically a high temperature resistant and low shrinkage PET film is selected as the substrate 31 .

[0088] In one embodiment, the substrate 31 should have a certain thickness. If the thickness of the substrate 31 is too thick, it will be difficult to form the through hole a later, and the cost will be high. If it is too thin, it will not be able to support the copper clad laminate. In this embodiment, the substrate 31 can be 10 μm-18 μm, and specifically can be about 12 μm.

[0089] In one embodiment, the first adhesive layer 32 and the second adhesive layer 33 may be acrylic adhesive or other conventional adhesives, and the viscosity is not too high. If the viscosity is too high, it is difficult to subsequently roll the first flexible circuit board 100 and the second flexible circuit board 200 and the adhesive layer 3, and the first flexible circuit board 100 and the second flexible circuit board 200 are easily broken during the rolling process. Figure 3 shown.

[0090] In one embodiment, the thickness of the first adhesive layer 32 and the second adhesive layer 33 are substantially the same, and the thickness of the entire adhesive layer 3 is substantially 20 μm-30 μm.

[0091] In one embodiment, before the adhesive layer 3 is used, the surfaces of the first adhesive layer 32 and the second adhesive layer 33 are both adhered with release films 4 .

[0092] S3, in conjunction with Figure 3 A first blind hole 15 and a second blind hole 25 are respectively formed on both sides of the first intermediate body 10 , the first blind hole 15 penetrates the first metal layer 12 and the first intermediate layer 11 , and the second blind hole 25 penetrates the fourth metal layer 23 and the second intermediate layer 21 .

[0093] In one embodiment, the first blind hole 15 and the second blind hole 25 are formed by laser drilling or mechanical drilling.

[0094] S4, again in conjunction with reference Figure 3 The first metal layer 12 and the fourth metal layer 23 on the outermost side of the first intermediate body 10 forming the first blind via 15 and the second blind via 25 respectively form the first circuit layer 14 and the second circuit layer 24 .

[0095] In one implementation, the first metal layer 12 and the fourth metal layer 23 may be exposed and developed to obtain the first circuit layer 14 and the second circuit layer 24 .

[0096] The specific process of forming the first circuit layer 14 and the second circuit layer 24 includes:

[0097] S41. The first intermediate 10 forming the first blind hole 15 and the second blind hole 25 is immersed in a black shadow liquid. The purpose is to deposit a dense, firm and conductive semi-conductive film on the hole wall of the first blind hole 15 and the second blind hole 25 formed after drilling, which serves as a base material for subsequent copper electroplating, so as to facilitate the next step of copper electroplating.

[0098] S42. Trim the first intermediate body 10 after the black shadow treatment, trim the edge of the first intermediate body 10 and remove the redundant part.

[0099] S43 . The first intermediate body 10 after the edge trimming process is subjected to lamination, exposure, and development to manufacture circuits, so as to form the first circuit layer 14 and the second circuit layer 24 .

[0100] The present application not only improves the efficiency of circuit production but also reduces the use of consumables by bonding two copper-clad laminates together to produce circuits, which is beneficial for reducing the consumables by half compared to the production of two separate flexible circuit boards during the lamination process.

[0101] S5, again in conjunction with Figure 3 , a first conductive layer 16 is formed in the first blind hole 15 formed with the semiconductive film to electrically connect the first circuit layer 14 with the second metal layer 13, so as to form a first flexible circuit board 100. A second conductive layer 26 is formed in the second blind hole 25 formed with the semiconductive film to electrically connect the second circuit layer 24 with the third metal layer 22, so as to form a second flexible circuit board 200. The first flexible circuit board 100 and the second flexible circuit board 200 are respectively located on both sides of the adhesive layer 3 to obtain a second intermediate 20.

[0102] In one embodiment, the first conductive layer 16 and the second conductive layer 26 are formed by electroplating.

[0103] In one embodiment, after the first flexible circuit board 100 and the second flexible circuit board 200 are formed, a film removal process is further included to remove the film material attached during circuit manufacturing.

[0104] In one embodiment, after forming the first flexible circuit board 100 and the second flexible circuit board 200, the method further includes:

[0105] A layer is added on the surface of the first circuit layer 14 to form at least one third circuit layer (not shown). The third circuit layer is electrically connected to the first circuit layer 14 .

[0106] Furthermore, a layer is added on the surface of the second circuit layer 24 to form at least one fourth circuit layer (not shown). The fourth circuit layer is electrically connected to the second circuit layer 24 .

[0107] This step can realize the online production of multi-layer flexible circuit boards, and the specific layer-adding method can be a traditional layer-adding method.

[0108] S6, in conjunction with Figure 3 and Figure 6 , a plurality of through holes a or third blind holes b are formed on the second intermediate body 20 to form an identification code.

[0109] The flexible circuit board manufacturing method of the present application requires forming an identification code on the second intermediate body 20 for in-plant serial connection. The present application can form a third blind hole b or a through hole a by laser drilling to produce a two-dimensional code.

[0110] In one embodiment, a through hole a is formed on the second intermediate body 20 to produce a two-dimensional code for identification, and the code reading rate of the through hole a is higher than that of the third blind hole b. This "AB process" will have a problem of poor code reading rate when the laser-formed three-blind hole b two-dimensional code does not increase the typesetting, that is, does not increase the cost. There are two solutions to this problem. The first is to increase the light source of the two-dimensional code reader to improve the code reading rate; the second is to laser-form through holes a at the waste area of ​​the second intermediate body 20 to form a through-hole two-dimensional code, thereby improving the code reading rate.

[0111] S7, again in conjunction with Figure 3 , the first flexible circuit board 100 and the second flexible circuit board 200 on the second intermediate body 20 are separated from the adhesive layer 3 and rolled.

[0112] Please refer to Figures 7 to 9 Specific methods of volume division include:

[0113] S71. Provide a reeling device 300, the reeling device 300 includes a reeling wheel group 5 and a reeling wheel group 6, the reeling wheel group 5 includes a first reeling wheel group 51 and a second reeling wheel group 52 arranged opposite to each other, the reeling wheel group 5 is used to reel the first flexible circuit board 100 and the second flexible circuit board 200, the reeling wheel group 6 is used to reel the reeled first flexible circuit board 100 and the second flexible circuit board 200, respectively.

[0114] In one embodiment, the first sub-reel wheel set 51 includes two rollers ①②, and the second sub-reel wheel set 52 includes two rollers ③④.

[0115] S72. Pass the second intermediate 20 through the first sub-reel wheel group 51 and the second sub-reel wheel group 52, and the first flexible circuit board 100 and the second flexible circuit board 200 are in contact with the first sub-reel wheel group 51 and the second sub-reel wheel group 52 respectively.

[0116] S73. The first winding wheel group 51 and the second winding wheel group 52 respectively wind up the first flexible circuit board 100 and the second flexible circuit board 200.

[0117] S74. The winding wheel group 6 respectively winds up the first flexible circuit board 100 and the second flexible circuit board 200 after being rolled up.

[0118] In one embodiment, the winding wheel group 6 includes a first winding wheel 61 (including a roller ⑤), a second winding wheel 62 (including a roller ⑦) and a third winding wheel 63 (including a roller ⑥), the first winding wheel 61 is used to wind up the first flexible circuit board 100, the second winding wheel 62 is used to wind up the adhesive layer 3, and the third winding wheel 63 is used to wind up the second flexible circuit board 200.

[0119] After the roll-to-roll bonding process is completed, the first flexible circuit board 100 and the second flexible circuit board 200 need to be separated for the subsequent production of multi-layer circuit boards. The difficulty in separating the first flexible circuit board 100 and the second flexible circuit board 200 that are bonded together is how to avoid damaging the first flexible circuit board 100 and the second flexible circuit board 200. Therefore, the selection of separation equipment is critical. Please refer to Figures 7 to 9 As shown, this application is divided into three volumes.

[0120] like Figure 7 As shown, the principle of the first reeling method is that a separation film (not shown) is provided on the roller ② of the first reeling wheel group 51 and the roller ③ of the second reeling wheel group 52, and the two separation films are respectively bonded to the first flexible circuit board 100 and the second flexible circuit board 200. The two separation films are respectively wound around the first reeling wheel group 51 and the second reeling wheel group 52 and wound around the first reeling wheel 61 and the third reeling wheel 63, and the middle adhesive layer 3 is directly reeled onto the second reeling wheel 62 to achieve the reeling action. At this time, the key is that the first flexible circuit board 100 and the second flexible circuit board 200 cannot be too tightly attached to the adhesive layer 3, and the adhesive layer 3 is selected to have a lower viscosity according to actual needs.

[0121] like Figure 8 As shown, the principle of the second reeling method is that the reeling device 300 further includes a separation mechanism 7, and the separation mechanism 7 is used to separate the first flexible circuit board 100 and the second flexible circuit board 200 on both sides of the adhesive layer 3. Specifically, the separation mechanism 7 is arranged on the side of the reeling wheel group 5 close to the reeling wheel group 6, and the separation mechanism 7 includes two separation knives respectively arranged corresponding to the first reeling wheel group 51 and the second reeling wheel group 52. The blade of the separation knife is perpendicular to the running direction of the first flexible circuit board 100 and the second flexible circuit board 200, the blade of the separation knife is arranged close to rollers ② and ③, and the blade is arranged close to the adhesive layer 3, and the first flexible circuit board 100 and the second flexible circuit board 200 are separated by the blades of the two separation knives and the pulling force of the rolling rollers.

[0122] like Fig. 9As shown, the principle of the third reeling method is to add a wet process during the separation process, adding a chemical agent that can react with the first adhesive layer 32 and the second adhesive layer 33 on the intermediate adhesive layer 3, and by configuring a suitable concentration, the agent can reduce the viscosity of the first adhesive layer 32 and the second adhesive layer 33, but does not damage the first flexible circuit board 100 and the second flexible circuit board 200, thereby separating the first flexible circuit board 100 and the second flexible circuit board 200. Specifically, the reeling device 300 includes a separation mechanism 8, which is arranged on the side of the reeling wheel group 5 away from the reeling wheel group 6, and the separation mechanism 8 includes a separation groove 81 and a separation liquid 82 contained in the separation groove 81, and the separation liquid 82 is used to reduce the viscosity of the first adhesive layer 32 and the second adhesive layer 33 on the adhesive layer 3, so as to separate the adhesive layer 3 from the first flexible circuit board 100 and the second flexible circuit board 200.

[0123] The adhesive layer 3 is bonded to the first flexible circuit board 100 and the second flexible circuit board 200, and is first passed through the separation liquid 82 (wet process) to weaken the viscosity of the first adhesive layer 32 and the second adhesive layer 33. Violent chemical reactions are avoided by controlling factors such as the concentration of the separation liquid 82, the line speed of the production line, and the contact time of the separation liquid 82, so as to ensure that the first flexible circuit board 100 and the second flexible circuit board 200 are not damaged. At the same time, the strength of the PET substrate is ensured to be sufficient so that the pulling force of the roller ⑦ will not break, thereby achieving the purpose of recycling the PET substrate.

[0124] In one embodiment, the separation liquid 82 is acetone (CH3COCH3), PH=7, and the neutral separation liquid 82 will not corrode or damage the first flexible circuit board 100 and the second flexible circuit board 200. The first adhesive layer 32 and the second adhesive layer 33 of the adhesive layer 3 we selected are acrylic acid (C3H4O2), and acetone can dissolve acrylic acid without damaging the dielectric layer (i.e., the first intermediate layer 11 and the second intermediate layer 21) of the flexible circuit board. It is understandable that the separation liquid 82 can also select other solvents that can dissolve the adhesive layer 3, such as cyclohexanone, chloroform, ethyl acetate, and methanol.

[0125] Acetone with a concentration of 50%-80% is added to the separation tank 81. The length of the separation tank 81 is between 1mm and 2mm. The tank is filled with acetone solution. The flexible circuit board and the acetone solution are contacted by immersion or spraying. The line speed of the separation equipment is controlled between 3m / min-4m / min. In this way, the time passing through the separation tank 81 is controlled between 15s-40s, which can ensure that the acetone reacts and dissolves with the acrylic acid on the double-sided tape, reduce the viscosity, and achieve the purpose of separation.

[0126] In one embodiment, the reeling device 300 further includes a cleaning and drying mechanism 9 disposed on the side of the reeling wheel group 6 away from the reeling wheel group 5, and the cleaning and drying mechanism 9 is used to clean and dry the first flexible circuit board 100 and the second flexible circuit board 200 after reeling. In this separation method, after separation, a cleaning and drying process is required to wash off the acetone solution on the copper foil and dry the flexible circuit board. Acetone is a neutral solvent and is soluble in water, so it can be cleaned with water.

[0127] In the present application, the method is used to prepare multiple single-layer or multi-layer flexible circuit boards. The multiple single-layer or multi-layer flexible circuit boards can be further made into inner circuit layers in the later stage, and a multi-layer flexible circuit board is formed by a conventional layer-adding method. The method of making the first flexible circuit board 100 and the second flexible circuit board 200 in the present application only requires one process, which is named "AB process" here. Figure 5 As shown. After cutting, the two copper-clad boards are rolled together with an adhesive layer. After laminating, the two copper-clad boards are simultaneously laser-processed to make blind holes, and the edges are trimmed and copper-plated at the same time, and then rolled. Finally, two single-layer or multi-layer flexible circuit boards can be obtained after one process. Then the inner layer circuit is made of the single-layer or multi-layer flexible circuit board, and the required various multi-layer flexible circuit boards are formed by conventional layer-adding methods. This production method effectively improves production efficiency and saves materials on the basis of streamlining the process.

[0128] Compared with the prior art, the manufacturing method of the flexible circuit board provided by the present invention adopts a roll-to-roll lamination production method, which can simultaneously produce two single-layer or multi-layer flexible circuit boards. On the basis of streamlining the process, it effectively improves production efficiency and increases production capacity, while saving materials and reducing costs.

Claims

1. A method for manufacturing a flexible circuit board, characterized in that: The following steps are involved: Providing a first copper-clad laminate and a second copper-clad laminate, wherein the first copper-clad laminate comprises a first metal layer and a second metal layer disposed opposite to each other, and the second copper-clad laminate comprises a third metal layer and a fourth metal layer disposed opposite to each other; Providing an adhesive layer, sequentially stacking the first copper clad laminate, the adhesive layer, and the second copper clad laminate so that the adhesive layer is located between the second metal layer and the third metal layer, and then laminating them to obtain a first intermediate; Forming a first circuit layer on the first metal layer at the outermost side of the first intermediate body, and electrically connecting the first circuit layer to the second metal layer to form a first flexible circuit board, forming a second circuit layer on the fourth metal layer at the outermost side of the intermediate body, and electrically connecting the second circuit layer to the third metal layer to form a second flexible circuit board; as well as The first flexible circuit board and the second flexible circuit board on the adhesive layer are rolled up, The volume division method comprises: A reeling device is provided, the reeling device comprises a reeling wheel group, a reeling wheel group and a separation mechanism, the reeling wheel group comprises a first reeling wheel group and a second reeling wheel group arranged opposite to each other, the reeling wheel group is used to reel the first flexible circuit board and the second flexible circuit board after reeling, the reeling wheel group is used to reel the first flexible circuit board and the second flexible circuit board after reeling, the separation mechanism is used to separate the first flexible circuit board and the second flexible circuit board from the adhesive layer, the separation mechanism is arranged on a side of the reeling wheel group away from the reeling wheel group, the separation mechanism comprises a separation groove and a separation liquid contained in the separation groove, the separation liquid is used to reduce the viscosity of the adhesive layer, so that the adhesive layer is separated from the first flexible circuit board and the second flexible circuit board without damaging the first flexible circuit board and the second flexible circuit board; The first flexible circuit board and the second flexible circuit board attached to the adhesive layer first pass through the separation liquid in the separation tank, and then pass through between the first sub-reel group and the second sub-reel group, so that the first flexible circuit board and the second flexible circuit board are in contact with the first sub-reel group and the second sub-reel group respectively; The first winding wheel group and the second winding wheel group respectively wind the first flexible circuit board and the second flexible circuit board; as well as The winding wheel group respectively winds up the first flexible circuit board, the second flexible circuit board and the adhesive layer after being rolled up. The winding wheel group includes a first winding wheel, a second winding wheel and a third winding wheel, the first winding wheel is used to wind up the first flexible circuit board, the second winding wheel is used to wind up the adhesive layer, and the third winding wheel is used to wind up the second flexible circuit board.

2. The method for manufacturing a flexible circuit board according to claim 1, characterized in that: Also includes: Forming a first blind hole and a second blind hole on both sides of the intermediate body respectively; as well as A first conductive layer is formed in the first blind hole to electrically connect the first circuit layer with the second metal layer, and a second conductive layer is formed in the second blind hole to electrically connect the second circuit layer with the third metal layer.

3. The method for manufacturing a flexible circuit board according to claim 1, characterized in that: Before the first flexible circuit board and the second flexible circuit board on the adhesive layer are rolled up, the method further comprises: Adding layers on the surface of the first circuit layer to form at least one third circuit layer, wherein the third circuit layer is electrically connected to the first circuit layer; and A layer is added on the surface of the second circuit layer to form at least one fourth circuit layer, and the fourth circuit layer is electrically connected to the second circuit layer.

4. The method for manufacturing a flexible circuit board according to claim 1, characterized in that: Also includes: The first intermediate is trimmed.

5. The method for manufacturing a flexible circuit board according to claim 1, characterized in that: Before the first flexible circuit board and the second flexible circuit board on the adhesive layer are rolled up, the method further comprises: A plurality of through holes or a plurality of third blind holes are formed on the first flexible circuit board and the second flexible circuit board to form an identification code.

6. The method for manufacturing a flexible circuit board according to claim 1, characterized in that: The winding device further comprises a cleaning and drying mechanism disposed on a side of the winding wheel group away from the winding wheel group, and the cleaning and drying mechanism is used for cleaning and drying the first flexible circuit board and the second flexible circuit board after winding.

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