Rigid-flex board with ultra-narrow flexible board bending area and preparation method of rigid-flex board

Abstract

The invention discloses an ultra-narrow soft board bending area rigid-flex board and a preparation method thereof, and relates to the technical field of printed circuit boards, the method comprises the following steps: providing a hard substrate, a soft substrate and a pure glue roll material in advance, then carrying out corresponding processing, and respectively obtaining a target soft core board, a target hard core board and a target pure glue layer; the flexible-rigid combined board is low in flowability, a target pure glue layer is used as a bonding material of a target soft core board and a target hard core board, a mode of opening a cover and then pressing is adopted, and rapid pressing equipment is adopted for rapidly pressing the target soft core board and the target hard core board, so that the glue flowing length of a flexible board bending area in the flexible-rigid combined board can be reduced, and the single-side glue flowing length can be reduced to be within 0.1 mm; the width of the flexible board bending area in the rigid-flex board can be reduced to 1mm, so that the size of the rigid-flex board can be reduced, the precision and integration of the product are improved, and the volume of an electronic device is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit boards, and in particular to a rigid-flexible board with an ultra-narrow flexible board bending zone and a preparation method thereof. Background Art

[0002] As devices become more integrated, sophisticated and smaller in size, the space requirements for electronic device assembly are getting narrower and narrower, and the requirements for the bending zone of the rigid-flex board are getting higher and higher. Reducing the width of the bending zone of the rigid-flex board can make the assembly space smaller. For this reason, it is necessary to develop a rigid-flex board with an ultra-narrow bending zone to meet the increasingly stringent assembly requirements.

[0003] At present, traditional rigid-flex boards use PP (minimum thickness of 60μm or more) as the bonding material between the flexible board and the rigid board, and adopt a post-opening process (pressing first and then opening the cover) to press PP between the flexible board and the rigid board. In the process of pressing different materials, PP is affected by high temperature and high pressure for about 4 hours, and the resin contained in it flows to the bending area of ​​the flexible board to form a layer of hard and brittle solidified flow glue. At present, the minimum length of the industry flow glue can be as low as 0.5mm on one side. According to the existing technology, it can only ensure that the double-sided flow glue in the bending area of ​​the flexible board is ≤1mm. It is necessary to reserve a minimum 1mm bending area of ​​the flexible board to ensure the bending effect of the flexible board. Therefore, the minimum width of the bending area of ​​the flexible board in the industry can only be 2mm.

[0004] Therefore, the existing technology still has the problem of using PP as a bonding material, which produces glue flow under the influence of high temperature and high pressure, making the bending zone width of the soft board in the hard-flex board as low as 2mm, limiting the precision and integration development of the hard-flex board. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a rigid-flexible board with an ultra-narrow soft board bending zone and a preparation method thereof, aiming to solve the problem that PP is used as a bonding material in the prior art and glue flow occurs under the influence of high temperature and high pressure, so that the width of the flexible board bending zone in the rigid-flexible board is as low as 2mm, which limits the precision and integration development of the rigid-flexible board.

[0006] The first aspect of the present invention is to provide a method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone, the method comprising: Provide hard substrates, soft substrates and pure film materials respectively; The hard substrate is cut to obtain a hard core board, a hard board circuit is made on the surface of the hard core board, and a window is cut and opened in a preset bending area of ​​the soft board to obtain a target hard core board; The soft substrate is cut to obtain a soft core board, a soft board circuit is made on the surface of the soft core board, and a protective film is attached to a preset bending area of ​​the soft board to obtain a target soft core board; Cutting the pure adhesive roll material to obtain a pure adhesive layer, cutting and opening windows in a preset bending area of ​​the soft board to obtain a target pure adhesive layer; Aligning the target pure glue layer to cover the two opposite sides of the target soft core board, arranging a buffer material on the surface of the target pure glue layer away from the target soft core board, and pressing with a fast pressing device to obtain a first-level pressed board; The target hard core board is aligned and covered on the opposite two side surfaces of the primary pressing board, and a buffer material is arranged on the surface of the target hard core board away from the primary pressing board, and is pressed by a fast pressing device to obtain a hard-soft combined board with an ultra-narrow soft board bending zone.

[0007] According to one aspect of the above technical solution, the hard substrate is cut to obtain a hard core board, a hard board circuit is made on the surface of the hard core board, and a window is cut and opened in a preset bending area of ​​the soft board to obtain a target hard core board, including: According to the preset required size data, the hard substrate is cut to obtain a hard core board; Applying a dry film to the hard core board, exposing, developing and etching, and forming a hard board circuit on the surface of the hard core board; The area of ​​the hard core board corresponding to the bending area of ​​the soft board is cut and opened to obtain the target hard core board.

[0008] According to one aspect of the above technical solution, the soft substrate is cut to obtain a soft core board, a soft board circuit is made on the surface of the soft core board, and a protective film is attached to a preset bending area of ​​the soft board to obtain the target soft core board, including: Cutting the soft substrate according to preset required size data to obtain a soft core board; Applying a dry film to the soft core board, exposing, developing and etching, and forming a soft board circuit on the surface of the soft core board; A protective film is attached to the surface of the soft board bending area in the soft core board to obtain the target soft core board.

[0009] According to one aspect of the above technical solution, the steps of cutting the pure adhesive roll to obtain a pure adhesive layer, cutting and opening windows in a preset bending area of ​​the soft board to obtain a target pure adhesive layer include: Cutting the pure film roll material according to preset required size data to obtain a pure film layer; The area of ​​the pure adhesive layer corresponding to the bending area of ​​the soft board is cut and opened to obtain a target pure adhesive layer.

[0010] According to one aspect of the above technical solution, the target pure glue layer is aligned and covered on the opposite two side surfaces of the target soft core board, and a buffer material is arranged on the surface of the target pure glue layer away from the target soft core board, and a fast pressing device is used for pressing to obtain a first-level pressed board, including: Aligning and covering the target pure glue layer on the opposite two side surfaces of the target soft core board, and arranging a buffer material on the surface of the target pure glue layer away from the target soft core board; The target pure glue layer and the target soft core board are quickly pressed by using a fast pressing device, so that the target pure glue layer and the target soft core board are combined to obtain a primary pressed board.

[0011] According to one aspect of the above technical solution, the target pure glue layer and the target soft core board are quickly pressed by using a fast pressing device to combine the target pure glue layer and the target soft core board to obtain a first-level pressed board. The pressing temperature is 180±10°C, the pre-pressing time is 30S-50S, the molding time is 60S, and the pressure is 150bar / cm 2 .

[0012] According to one aspect of the above technical solution, the target hard core board is aligned and covered on the opposite two side surfaces of the primary press board, and a buffer material is arranged on the surface of the target hard core board away from the primary press board, and a fast pressing device is used for pressing to obtain a soft-hard combination board with an ultra-narrow soft board bending zone, including: Aligning the target hard core board to cover the two opposite sides of the primary press board, and arranging a buffer material on the surface of the target hard core board away from the primary press board; The target rigid core board is pressed together with the primary pressing board by using a fast pressing device to obtain a rigid-flexible board with an ultra-narrow flexible board bending zone.

[0013] According to one aspect of the above technical solution, in the step of using a fast pressing device for pressing to combine the target hard core board with the first-level pressing board to obtain a soft-hard combination board with an ultra-narrow soft board bending zone, the pressing temperature is 180±10℃, the pre-pressing time is 30S-50S, the molding time is 60S, and the pressure is 150bar / cm 2 .

[0014] According to one aspect of the above technical solution, before the step of using a fast pressing device to press together the target rigid core board and the primary pressing board to obtain a rigid-flexible board with an ultra-narrow flexible board bending zone, the method further includes: Rivets are arranged on the side surfaces of the target hard core plate and the primary pressed plate to pre-fix the target hard core plate and the primary pressed plate.

[0015] The second aspect of the present invention is to provide a rigid-flexible board with an ultra-narrow flexible board bending zone, which is prepared by the preparation method described in the above technical solution, and the width of the flexible board bending zone is ≤1mm.

[0016] Compared with the prior art, the ultra-narrow flexible board bending zone rigid-flexible board and the preparation method thereof shown in the present invention have the following beneficial effects: In the method shown in the present invention, a target soft core board, a target hard core board and a target pure glue layer are pre-made. Since the target pure glue layer is pure glue with low fluidity, the target pure glue layer is used as the bonding material between the target soft core board and the target hard core board, and the method of first opening the cover and then pressing is adopted. The fast pressing equipment is used to quickly press them, which can reduce the glue flow length of the bending zone of the soft board in the hard-soft combination board. The single-sided glue flow length can be reduced to within 0.1mm, so that the width of the bending zone of the soft board in the hard-soft combination board can be reduced to 1mm, thereby reducing the size of the hard-soft combination board, improving the precision and integration of the product, and reducing the volume of electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 It is a schematic diagram of the process of preparing a rigid-flexible board with an ultra-narrow flexible board bending zone in one embodiment of the present invention; Figure 2 Schematic diagram of the structure of a rigid-flexible board in an ultra-narrow flexible board bending area in one embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. Several embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0019] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0021] Embodiment 1 See also Figure 1 The first embodiment of the present invention provides a method for preparing a rigid-flexible board with an ultra-narrow flexible board bending region, which is used to prepare a rigid-flexible board with an ultra-narrow flexible board bending region. The method shown in this embodiment includes steps S10 to S60: In step S10, a hard substrate, a soft substrate and a pure film material are provided respectively.

[0022] Step S20, cutting the hard substrate to obtain a hard core board, making a hard board circuit on the surface of the hard core board, and cutting and opening windows in a preset soft board bending area to obtain a target hard core board.

[0023] In this embodiment, the steps of cutting the hard substrate to obtain a hard core board, making a hard board circuit on the surface of the hard core board, and cutting and opening windows in a preset bending area of ​​the soft board to obtain a target hard core board include: According to the preset required size data, the hard substrate is cut to obtain a hard core board; Applying a dry film to the hard core board, exposing, developing and etching, and forming a hard board circuit on the surface of the hard core board; The area of ​​the hard core board corresponding to the bending area of ​​the soft board is cut and opened to obtain the target hard core board.

[0024] Specifically, after providing the hard substrate, the hard substrate will be cut according to the preset required size data to obtain a hard core board that meets the required size, i.e., a hard board core. Then, a dry film will be attached to the surface of the hard core board, which will be exposed, developed and etched to form a hard board circuit on the surface of the hard core board. The area of ​​the hard core board corresponding to the bending zone of the soft board will be cut and opened to make the area of ​​the hard core board corresponding to the bending zone of the soft board appear hollow, thereby obtaining the target hard core board.

[0025] Step S30, cutting the soft substrate to obtain a soft core board, making a soft board circuit on the surface of the soft core board, and attaching a protective film to a preset bending area of ​​the soft board to obtain a target soft core board.

[0026] In this embodiment, the soft substrate is cut to obtain a soft core board, a soft board circuit is made on the surface of the soft core board, and a protective film is attached to a preset bending area of ​​the soft board to obtain the target soft core board, including: Cutting the soft substrate according to preset required size data to obtain a soft core board; Applying a dry film to the soft core board, exposing, developing and etching, and forming a soft board circuit on the surface of the soft core board; A protective film is attached to the surface of the soft board bending area in the soft core board to obtain the target soft core board.

[0027] Specifically, after providing the soft substrate, the soft core board will be cut according to the preset required size data to obtain a hard core board that meets the required size, namely the soft core, and then a dry film will be attached to the surface of the soft core board, which will be exposed, developed and etched to form a soft board circuit on the surface of the soft core board, and a protective film will be attached to the surface of the soft bending area in the soft core board to obtain the target soft core board.

[0028] Step S40, cutting the pure adhesive roll to obtain a pure adhesive layer, cutting and opening windows in a preset bending area of ​​the soft board to obtain a target pure adhesive layer.

[0029] In this embodiment, the steps of cutting the pure adhesive roll to obtain a pure adhesive layer, cutting and opening a window in a preset bending area of ​​the soft board to obtain a target pure adhesive layer include: Cutting the pure film roll material according to preset required size data to obtain a pure film layer; The area of ​​the pure adhesive layer corresponding to the bending area of ​​the soft board is cut and opened to obtain a target pure adhesive layer.

[0030] Specifically, after providing the pure film material, the pure film material will be cut according to the preset required size data to obtain a pure glue layer, and the area corresponding to the bending zone of the soft board in the pure glue layer will be cut and opened, so that the area of ​​the pure glue layer corresponding to the bending zone of the soft board is hollowed out to obtain a target pure glue layer, and the thickness of the target pure glue layer is 20μm-30μm.

[0031] As mentioned above, after providing a hard substrate, a soft substrate and a pure adhesive roll material, they are cut and processed to obtain a target hard core board, a target soft core board and a target pure adhesive layer, respectively, to construct the above-mentioned ultra-narrow soft board bending zone hard-soft combination board.

[0032] Step S50, aligning and covering the target pure glue layer on the opposite sides of the target soft core board, arranging a buffer material on the surface of the target pure glue layer away from the target soft core board, and pressing with a fast pressing device to obtain a first-level pressed board.

[0033] In this embodiment, the target pure glue layer is aligned and covered on the opposite two side surfaces of the target soft core board, and a buffer material is arranged on the surface of the target pure glue layer away from the target soft core board, and a fast pressing device is used for pressing to obtain a first-level pressed board, including: Aligning and covering the target pure glue layer on the opposite two side surfaces of the target soft core board, and arranging a buffer material on the surface of the target pure glue layer away from the target soft core board; The target pure glue layer and the target soft core board are quickly pressed by using a fast pressing device, so that the target pure glue layer and the target soft core board are combined to obtain a primary pressed board.

[0034] Among them, the target pure glue layer and the target soft core board are quickly pressed by using a fast pressing device to combine the target pure glue layer and the target soft core board to obtain a first-level pressed board. The pressing temperature is 180±10℃, the pre-pressing time is 30S-50S, the molding time is 60S, and the pressure is 150bar / cm 2 .

[0035] Specifically, after the target soft core board and the target pure adhesive layer are pre-made, the target soft core board and the target pure adhesive layer will be pressed together to make them one body. Specifically, the target pure adhesive layers are arranged on the opposite sides of the target soft core board and aligned. Then, the pressing temperature is 180±10℃, the pre-pressing time is 30S-50S, the molding time is 60S, and the pressure is 150bar / cm 2 Under the condition of, a fast pressing device is used to press the target soft core board and the target pure adhesive layer, so that the target pure adhesive layer is attached to the opposite side surfaces of the target soft core board; and in order to ensure that it can be quickly separated from the fast pressing device, a buffer material, such as a release film, is arranged on the surface of the target pure adhesive layer away from the target soft core board, that is, between the target pure adhesive layer and the pressing part of the fast pressing device, so as to facilitate the rapid separation of the primary pressing board and the fast pressing device, and at the same time avoid the target pure adhesive layer from being short of material after pressing.

[0036] Step S60, aligning the target hard core board to cover the opposite two side surfaces of the primary pressing plate, arranging buffer material on the surface of the target hard core board away from the primary pressing plate, and pressing with fast pressing equipment to obtain a hard-soft combination board with an ultra-narrow soft board bending zone.

[0037] In this embodiment, the target hard core board is aligned and covered on the opposite two side surfaces of the primary press board, and a buffer material is arranged on the surface of the target hard core board away from the primary press board, and a fast pressing device is used for pressing to obtain a soft-hard combination board with an ultra-narrow soft board bending zone, including: Aligning the target hard core board to cover the two opposite sides of the primary press board, and arranging a buffer material on the surface of the target hard core board away from the primary press board; The target rigid core board is pressed together with the primary pressing board by using a fast pressing device to obtain a rigid-flexible board with an ultra-narrow flexible board bending zone.

[0038] Among them, in the step of using a fast pressing device to press the target hard core board and the first-level pressing board to obtain a soft-hard combination board with an ultra-narrow soft board bending zone, the pressing temperature is 180±10℃, the pre-pressing time is 30S-50S, the molding time is 60S, and the pressure is 150bar / cm 2 .

[0039] Specifically, after the target soft core board and the target pure adhesive layer are pressed together to form a first-level pressed board by a fast pressing device, two pre-made target hard core boards are arranged on the opposite sides of the first-level pressed board and aligned so that the target hard core boards cover the opposite sides of the first-level pressed board. Then, the pressing temperature is 180±10℃, the pre-pressing time is 30S-50S, the molding time is 60S, and the pressure is 150bar / cm 2 Under the condition of, a fast pressing device is used to press the target hard core board and the first-level pressing board, so that the target hard core board is attached to the opposite two side surfaces of the target soft core board through the target pure glue layer in the first-level pressing board, so as to obtain a hard-soft combination board with an ultra-narrow soft board bending zone; and in order to ensure that the pressure applied by the fast pressing device to the target hard core board is evenly distributed and prevent cracks from occurring in the target hard core board, a buffer material is also arranged on the surface of the target hard core board away from the first-level pressing board, that is, between the target hard core board and the pressing part of the fast pressing device, such as TPX. The pressure can be evenly transmitted and buffered by TPX, which can effectively improve the pressing yield of the hard-soft combination board.

[0040] Furthermore, before laminating the target hard core board and the primary pressing board, after aligning the target hard core board and the primary pressing board, rivets can be arranged on the sides of the target hard core board and the primary pressing board to pre-fix the target hard core board and the primary pressing board, thereby preventing deviation during transportation or laminating, which can also effectively improve the laminating yield of the soft-hard combination board.

[0041] In addition, after the target soft core board, the target hard core board and the target pure glue layer are pressed together to obtain a hard-flex board, etching, solder mask and other processes are required. The etching process includes pre-treatment, exposure, development and etching. The excess glue layer on the surface of the hard-flex board is removed by the etching process. Due to the degumming / copper deposition process, the bending area of ​​the soft board in the hard-flex board is not covered by the target hard core board and is in a leaking state. During the degumming / copper deposition process, there will be partial separation between the buffer material such as the release film and the target pure glue layer, and the appearance will be bubbling. The release film and the target pure glue layer need to be re-pressed together by a fast pressing device. The process parameters are as follows: Use fast pressing equipment to press. Before pressing, use TPX as a buffer material and place it on the upper and lower surfaces of the soft and hard board to cover the opposite sides of the bending area of ​​the soft board, or completely cover the opposite sides of the soft and hard board. Then press quickly. The pressing temperature is 180±10℃, the pre-pressing time is 30S-50S, the molding time is 60S, and the pressure is 150bar / cm 2 .

[0042] In summary, compared with the prior art, the method for preparing the ultra-narrow flexible board bending zone rigid-flexible board shown in this embodiment has the following beneficial effects: In the method shown in the present embodiment, a target soft core board, a target hard core board and a target pure glue layer are prefabricated. Since the target pure glue layer is pure glue with low fluidity, the target pure glue layer is used as the bonding material between the target soft core board and the target hard core board. The method of first opening the cover and then pressing is adopted, and a fast pressing device is used to quickly press them. This can reduce the glue flow length in the bending zone of the soft board in the hard-soft combination board, and the single-sided glue flow length can be reduced to within 0.1mm, so that the width of the bending zone of the soft board in the hard-soft combination board can be reduced to 1mm, thereby reducing the size of the hard-soft combination board, improving the precision and integration of the product, and reducing the volume of electronic devices.

[0043] Embodiment 2 See also Figure 2 The second embodiment of the present invention provides a rigid-flexible board with an ultra-narrow flexible board bending zone. The rigid-flexible board with an ultra-narrow flexible board bending zone shown in this embodiment is prepared by the preparation method described in the first embodiment, and the width of the flexible board bending zone is ≤1mm.

[0044] In this embodiment, the hard-flex board includes 1 target soft core board 20, 2 target pure adhesive layers 30 and 2 target hard core boards 10; on opposite sides of the target soft core board 20, there are target pure adhesive layers 30 and target hard core boards 10 respectively.

[0045] Among them, L1 and L2 are copper layers deposited on opposite sides of the first target hard core board 10 in this embodiment, L3 and L4 are copper layers deposited on opposite sides of the target soft core board 20, and L5 and L6 are copper layers deposited on opposite sides of the second target hard core board 10 in this embodiment. Specifically, the target soft core board 20 and the target hard core board 10 are connected together through the target pure glue layer 30 to form a soft-hard combination board. In the soft-hard combination board, the width of the bending area of ​​the soft board is ≤1mm, that is, the width of the area covered by the buffer material 40 is ≤1mm, and the buffer material 40 needs to be removed after the quick pressing is completed. The use of the soft-hard combination board shown in this embodiment can be beneficial to improving the precision and integration of the product to reduce the volume of electronic devices.

[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0047] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone, characterized in that: The method comprises: Provide hard substrates, soft substrates and pure film materials respectively; The hard substrate is cut to obtain a hard core board, a hard board circuit is made on the surface of the hard core board, and a window is cut and opened in a preset bending area of ​​the soft board to obtain a target hard core board; The soft substrate is cut to obtain a soft core board, a soft board circuit is made on the surface of the soft core board, and a protective film is attached to a preset bending area of ​​the soft board to obtain a target soft core board; Cutting the pure adhesive roll material to obtain a pure adhesive layer, cutting and opening windows in a preset bending area of ​​the soft board to obtain a target pure adhesive layer; Aligning the target pure glue layer to cover the two opposite sides of the target soft core board, arranging a buffer material on the surface of the target pure glue layer away from the target soft core board, and pressing with a fast pressing device to obtain a first-level pressed board; The target hard core board is aligned and covered on the opposite two side surfaces of the primary pressing board, and a buffer material is arranged on the surface of the target hard core board away from the primary pressing board, and is pressed by a fast pressing device to obtain a hard-soft combined board with an ultra-narrow soft board bending zone.

2. The method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone according to claim 1, characterized in that: The steps of cutting the hard substrate to obtain a hard core board, making a hard board circuit on the surface of the hard core board, and cutting and opening windows in a preset bending area of ​​the soft board to obtain a target hard core board include: According to the preset required size data, the hard substrate is cut to obtain a hard core board; Applying a dry film to the hard core board, exposing, developing and etching, and forming a hard board circuit on the surface of the hard core board; The area of ​​the hard core board corresponding to the bending area of ​​the soft board is cut and opened to obtain the target hard core board.

3. The method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone according to claim 2, characterized in that: The steps of cutting the soft substrate to obtain a soft core board, making a soft board circuit on the surface of the soft core board, and attaching a protective film to a preset bending area of ​​the soft board to obtain a target soft core board include: Cutting the soft substrate according to preset required size data to obtain a soft core board; Applying a dry film to the soft core board, exposing, developing and etching, and forming a soft board circuit on the surface of the soft core board; A protective film is attached to the surface of the soft board bending area in the soft core board to obtain the target soft core board.

4. The method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone according to claim 1, characterized in that: The steps of cutting the pure adhesive roll material to obtain a pure adhesive layer, cutting and opening windows in a preset bending area of ​​the soft board to obtain a target pure adhesive layer include: Cutting the pure film roll material according to preset required size data to obtain a pure film layer; The area of ​​the pure adhesive layer corresponding to the bending area of ​​the soft board is cut and opened to obtain a target pure adhesive layer.

5. The method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone according to any one of claims 1 to 4, characterized in that: The step of aligning and covering the target pure glue layer on the opposite two side surfaces of the target soft core board, arranging a buffer material on the surface of the target pure glue layer away from the target soft core board, and pressing with a fast pressing device to obtain a first-level pressed board includes: Aligning and covering the target pure glue layer on the opposite two side surfaces of the target soft core board, and arranging a buffer material on the surface of the target pure glue layer away from the target soft core board; The target pure glue layer and the target soft core board are quickly pressed by using a fast pressing device, so that the target pure glue layer and the target soft core board are combined to obtain a primary pressed board.

6. The method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone according to claim 5, characterized in that: The target pure glue layer and the target soft core board are fast pressed by using a fast pressing device to combine the target pure glue layer and the target soft core board to obtain a first-level pressed board. The pressing temperature is 180±10°C, the pre-pressing time is 30S-50S, the molding time is 60S, and the pressure is 150bar / cm 2 .

7. The method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone according to claim 6, characterized in that: The steps of aligning and covering the target hard core board on the opposite two side surfaces of the primary pressing board, arranging a buffer material on the surface of the target hard core board away from the primary pressing board, and pressing the target hard core board with a fast pressing device to obtain a hard-flexible board with an ultra-narrow soft board bending zone include: Aligning the target hard core board to cover the two opposite sides of the primary press board, and arranging a buffer material on the surface of the target hard core board away from the primary press board; The target rigid core board is pressed together with the primary pressing board by using a fast pressing device to obtain a rigid-flexible board with an ultra-narrow flexible board bending zone.

8. The method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone according to claim 7, characterized in that: In the step of using a fast pressing device to press together the target hard core board and the first-level pressing board to obtain a soft-hard combination board with an ultra-narrow soft board bending zone, the pressing temperature is 180±10℃, the pre-pressing time is 30S-50S, the molding time is 60S, and the pressure is 150bar / cm 2 .

9. The method for preparing a rigid-flexible board with an ultra-narrow flexible board bending zone according to claim 7, characterized in that: Before the step of using a fast pressing device to press together the target rigid core board and the primary pressing board to obtain a rigid-flexible board with an ultra-narrow flexible board bending zone, the method further includes: Rivets are arranged on the side surfaces of the target hard core plate and the primary pressed plate to pre-fix the target hard core plate and the primary pressed plate.

10. A rigid-flexible board with an ultra-narrow flexible board bending zone, characterized in that: The soft board is prepared by the preparation method according to any one of claims 1 to 9, wherein the width of the bending zone of the soft board is ≤1 mm.

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