A manufacturing method of a large aspect ratio rigid-flex combined board of a kind of harness type

Abstract

The application discloses a kind of methods for making large length-width ratio rigid-flex combination board of harness type, copper pattern plate with connecting copper pattern across bending area and extending into invalid area is made;Corresponding to connecting copper pattern, connecting site window pattern is made from the edge of bending area to invalid area, but not beyond the part of connecting copper pattern into invalid area;Take double-sided flexible copper-clad plate, mill micro slot in the edge of bending area corresponding to the area of connecting copper pattern, then stack between two copper pattern plates and press, connecting copper pattern is towards plate outside;Then mill through slot in the edge of bending area, form middle core plate, stack and press the above plate layer again, then uncover and etch in bending area, finally form;Overall processing forms process flow with complete processing logic based on pattern distribution design and size relationship design, forms processing effect matched with each other, effectively improves the processing quality of rigid-flex combination board.

Description

Technical Field

[0001] This invention relates to the field of flexible board manufacturing, and more particularly to a method for manufacturing a wire harness-type high aspect ratio rigid-flex board. Background Technology

[0002] With the development of intelligent connected vehicles and low-altitude aircraft, rigid-flex boards have emerged that use flexible circuit boards to replace wire harnesses. These are wire harness-like rigid-flex boards, where the flexible areas generally have a large aspect ratio to meet the needs of wire harness connections along longer paths.

[0003] In the processing of wire harness-type rigid-flex PCBs with large aspect ratios, a cover film needs to be laid on the surface of the flexible circuit board. If the aspect ratio of the cover film is large, the several wire harness-type cover films formed are prone to problems such as scattering and difficulty in alignment and bonding during processing. Furthermore, if the shape of the cover film is not made in advance and is made together with the whole board during molding, the milling path of the flexible board is long, which can easily cause milling pulling and tearing problems. If laser cutting is used for molding, it is easy to cause the problem of carbon black being difficult to remove from the finished board after molding, which can lead to short circuits.

[0004] Therefore, in order to solve the problems mentioned above, it is necessary to provide a method for manufacturing a type of wire harness-type rigid-flex plate with a large aspect ratio. Summary of the Invention

[0005] This invention aims to solve the comprehensive problems of existing wire harness-type rigid-flex panels with large aspect ratios, such as easy scattering and difficulty in alignment and bonding during processing when the cover film has a large aspect ratio. It proposes a method for manufacturing a wire harness-type rigid-flex panel with a large aspect ratio. The rigid-flex panel is designed with forming lines, the area within the forming lines is the effective area, and the remaining area is the ineffective area. The effective area includes a bending area and a rigid area. The manufacturing method includes the following steps:

[0006] S10: Take a first cover film, the surface of which is coated with a copper layer. A first cover film window pattern is formed on the first cover film corresponding to the rigid area. Then, a first circuit pattern is formed on the copper layer to form a copper pattern board. Forming the first circuit pattern includes creating a connecting copper pattern in the bending area. The connecting copper pattern spans the bending area and extends into the ineffective area, with the portion extending into the ineffective area being the extension length. Forming the first cover film window pattern includes creating a connecting position window pattern on the first cover film corresponding to the connecting copper pattern. The connecting position window pattern extends from the edge of the bending area to the ineffective area. The width of the connecting position window pattern is greater than or equal to the width of the connecting copper pattern, and the length of the connecting position window pattern is less than the extension length.

[0007] S20: Take another double-sided flexible copper-clad laminate, make a second circuit pattern to form a core board pattern, and mill micro-grooves at the edge of the bending area and in the area corresponding to the connecting copper pattern to form a micro-groove board; then place the micro-groove board between the two copper pattern boards for stacking and pressing, with the connecting copper pattern facing away from the micro-groove board; then mill through grooves at the edge of the bending area except for the connecting copper pattern to form an intermediate core board;

[0008] S30: Take two layers of semi-cured sheets and attach a reverse cover film to one side of the area corresponding to the bending area to form a first semi-cured layer and a second semi-cured layer respectively.

[0009] S40: Fabricate a first rigid core board and a second rigid core board, and stack the first rigid core board, the first semi-cured layer, the intermediate core board, the second semi-cured layer and the second rigid core board in sequence from top to bottom to form a stacked structure, and then press them together to form a press-fitted plate; the reverse cover film faces the intermediate core board.

[0010] S50: The bending area of ​​the press plate is peeled off to expose the connecting copper pattern, forming a peeled rigid flexible plate;

[0011] S60: The cover rigid-flex plate is etched, and the rigid area is shaped to form the rigid-flex plate.

[0012] Furthermore, the copper pattern board is manufactured by punching the first cover film to create a windowed pattern, the first cover film windowed pattern including the connection position windowed pattern, forming a windowed cover film, attaching a micro-adhesive film layer to the first side of the copper layer, pressing the second side with the windowed cover film, removing the micro-adhesive film layer, and manufacturing the first circuit pattern to form the copper pattern board.

[0013] Furthermore, the connection point window pattern is created by laser ablation of the first covering film of the connection point window pattern.

[0014] Furthermore, fabricating the copper pattern board includes fabricating a first grid copper pattern in the region of the invalid area.

[0015] Furthermore, fabricating the intermediate core board includes creating a second grid copper pattern in the region of the ineffective area.

[0016] Furthermore, the side of the reverse covering film adjacent to the rigid area is recessed inward corresponding to the bending area, while the other sides extend into the ineffective area.

[0017] Furthermore, the uncovering process involves performing controlled-depth milling on the bending area of ​​the pressed plate, with the controlled-depth milling depth extending from the plate surface to the reverse cover film.

[0018] Furthermore, the distance between the length of the connection window pattern and the extension length of the connection copper pattern is 25 μm to 105 μm.

[0019] Furthermore, the milled microgrooves are cut using laser milling.

[0020] Furthermore, the milling width of the microgroove is 5μm to 25μm.

[0021] This invention's technical solution creates connection point patterns, allowing the cover film in the bending area and the cover film in the ineffective area to form a continuous, integrated structure. This effectively avoids the problems of existing technologies where multiple wire-bundle cover films are prone to scattering and difficult alignment during processing. By creating corresponding window patterns on the cover film and laser-cutting through-grooves on the edges of the bending area to form a pre-formed bending area, the edges of the bending area are connected only by the connection point patterns, without any cover film connection. Utilizing the dimensional relationship between the back-attached cover film and the bending area in the laminating plate, the copper patterns at the connection points are exposed through controlled-depth milling. After etching to remove these patterns, the rigid area is then shaped, effectively preventing milling pulls and tears. It also effectively avoids the problems of carbon black generated during laser cutting of the bending area, which can lead to short circuits. The overall processing forms a complete processing flow based on pattern distribution design and dimensional relationship design, resulting in a matching processing effect and effectively improving the processing quality of the rigid-flex board. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 For process flow diagram;

[0024] Figure 2 This is a schematic diagram of the cross-sectional structure of a copper graphic plate;

[0025] Figure 3 for Figure 2 A schematic diagram of the front structure;

[0026] Figure 4 for Figure 2 A schematic diagram of the reverse structure;

[0027] Figure 5 This is a schematic diagram of the planar structure of the microgroove plate;

[0028] Figure 6This is a schematic diagram of the cross-sectional structure of the laminated structure;

[0029] Figure 7 This is a schematic diagram of the front side of the core board;

[0030] Figure 8 This is a schematic diagram of the cross-sectional structure of the stacked structure;

[0031] Figure 9 This is a schematic diagram of the cross-sectional structure of the press-fit plate;

[0032] Figure 10 A schematic diagram of the planar structure for uncovering the rigid-flex plate;

[0033] Figure 11 for Figure 10 Schematic diagram of the AA section structure;

[0034] Figure 12 This is a schematic diagram of the cross-sectional structure of a rigid-flexible plate.

[0035] Explanation of icon numbers:

[0036]

[0037] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that all directional indications (such as up, down, left, right, front, back, inside, outside, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0040] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0042] Please see Figure 1 , Figure 1 This is a process flow diagram.

[0043] The manufacturing process of this invention includes using Figure 1 The implementation of each step in the process will be described below. Figure 1 The process of each step will be explained step by step.

[0044] Please see Figure 2 , Figure 3 and Figure 4 , Figure 2 This is a schematic diagram of the cross-sectional structure of a copper graphic plate; Figure 3 for Figure 2 A schematic diagram of the front structure; Figure 4 for Figure 2 A schematic diagram of the reverse structure.

[0045] The rigid-flexible bonding plate 90 of this embodiment is designed with a forming line 100. The area within the forming line 100 is the effective area 100A, which includes a bending area 1010A and a rigid area 1020A. The remaining area is the ineffective area 100B.

[0046] Step S10:

[0047] Take the first cover film, the surface of which is covered with a copper layer. Corresponding to the rigid area 1020A, make a first cover film window pattern 1040 on the first cover film. Then, make a first circuit pattern on the copper layer to form a copper pattern board 10.

[0048] The key to this embodiment lies in the fabrication of the first circuit pattern, including the fabrication of a connecting copper pattern 1010 in 1010A. The connecting copper pattern 1010 spans the bending area 1010A and extends into the ineffective area 100B. The portion extending into the ineffective area 100B forms an extension length of 1050, so that the cover film of the bending area 1010A and the cover film of the ineffective area 100B form a continuous integral structure through the connecting copper pattern 1010. This effectively avoids the problems of several wire harness-type cover films formed in the prior art being prone to scattering and difficult to align and bond during processing.

[0049] Since the milling process of the connecting copper pattern 1010 requires a much higher temperature than the milling process of the cover film, after the pressing process, the area of ​​the first cover film corresponding to the connecting copper pattern 1010 is blocked, making it difficult to perform milling. Therefore, in this process, the production of the first cover film window pattern 1040 includes making a connection position window pattern 1030 on the first cover film corresponding to the connecting copper pattern 1010, so that the connecting copper pattern 1010 in this area is exposed, forming a pre-milling, and the connection position window pattern 1030 extends from the edge of the bending area 1010A to the invalid area 100B.

[0050] Furthermore, the width of the connecting window pattern 1030 is greater than or equal to the width of the connecting copper pattern 1010, and the length of the connecting window pattern 1030 is less than the insertion length, forming a partial exposure of the connecting window pattern 1030. By widening the width of the connecting window pattern 1030, the laser milling of the cover film adjacent to the connecting copper pattern 1010 is reduced, effectively avoiding the fact that during the subsequent laser milling process, some heat will be conducted to the internal cover film through the connecting copper pattern 1010. When the internal cover film is heated, it may deform, melt, and generate carbon powder.

[0051] In one embodiment, the copper pattern board is manufactured by punching a first cover film to create a first cover film window pattern 1040, which includes a connecting position window pattern 1030, forming a windowed cover film. Punching the first cover film window pattern 1040 produces less waste compared to laser cutting, and has advantages such as higher speed and lower cost, thus improving processing efficiency. Next, a micro-adhesive film layer is attached to the first side of the copper layer, and the second side is pressed against the windowed cover film. The micro-adhesive film layer is then removed to create a first circuit pattern, forming the copper pattern board 10. By attaching a micro-adhesive film layer to one side and then pressing the other side against the punched cover film, the micro-adhesive film layer provides temporary fixation and support, allowing the cover film to adhere stably to the copper layer surface, preventing positional shifts during subsequent removal operations.

[0052] In one embodiment, the connection opening pattern 1030 is made by laser ablation of the first cover film of the connection opening pattern 1030. Laser ablation can provide higher processing accuracy and reduce mechanical stress on the material, thereby avoiding the stretching deformation or damage to the material caused by mechanical punching.

[0053] Furthermore, the length of the connecting window pattern 1030 is 25μm to 105μm less than the extension length 1050 of the connecting copper pattern 1010. This ensures the stability of the connecting copper pattern 1010 in connecting the cover film of the bending area 1010A and the cover film of the ineffective area 100B to form a continuous structure. It effectively avoids problems such as detachment and misalignment of the connecting copper pattern 1010 after subsequent pressing due to excessively large window openings.

[0054] In one embodiment, fabricating the copper pattern board 10 includes fabricating a first grid copper pattern 1020 in the area of ​​the ineffective region 100B. This serves two purposes: firstly, it provides a large-area coverage film for anti-slip bonding and improves the bonding force between the bonding layers; secondly, because copper has good thermal conductivity, it helps maintain the overall operating temperature of the circuit board during the processing.

[0055] Please see Figure 5 picture, Figure 6 and Figure 7 , Figure 5 This is a schematic diagram of the planar structure of the microgroove plate; Figure 6 This is a schematic diagram of the cross-sectional structure of the laminated structure; Figure 7 This is a schematic diagram of the front side of the core board.

[0056] Step S20:

[0057] Next, take a double-sided flexible copper-clad laminate and make a second circuit pattern to form a core board pattern 1040. On the edge of the bending area and in the area corresponding to the copper pattern 1010, mill microgrooves 2020 to form a pre-milling for the bending area 1010A. This provides a processing basis for the subsequent forming process without the need to form the bending area 1010A. The whole is formed into a microgroove board 20.

[0058] Next, the microgroove plate 20 is stacked between two copper graphic plates 10 to form a stacked structure 30, and then pressed together. The connecting copper graphic 1010 faces away from the microgroove plate 20. Then, a through groove 4010 is milled on the edge of the bending area 1010A except for the connecting copper graphic 1010 to form an intermediate core plate 40. The connecting copper graphic 1010 is located on the outer surface of the intermediate core plate 40, which provides a processing basis for the subsequent process of uncovering and exposing the connecting copper graphic 1010. Then, laser milling is performed to connect with the connecting window graphic 1030 made in the previous process to form a through groove 4010, thus forming the bending area 1010A. In the subsequent whole plate forming process, the bending area 1010A is avoided from being milled, which effectively prevents problems such as pulling and tearing caused by milling the flexible plate of the bending area 1010A.

[0059] Furthermore, the fabrication of the intermediate core board 40 includes fabricating a second grid copper pattern 2030 in the region of the ineffective area 100B. Similar to the first grid copper pattern 1020 mentioned above, the second grid copper pattern 2030 can also play a good role in heat dissipation and anti-slip, which will not be described in detail here.

[0060] In this embodiment, since the microgroove 2020 is located at the edge of the bending area 1010A, laser milling is used to mill the microgroove 2020. This allows for precise control of the cutting path, effectively avoiding the removal of excess material due to inaccurate positioning and improving the processing accuracy. The milling width of the microgroove is 5μm to 25μm. The width of the laser-milled ablated microgroove should not be too wide, otherwise it may cause a pressing depression problem.

[0061] Please see Figure 8 , Figure 8 This is a schematic diagram of the cross-sectional structure of the stacked structure.

[0062] Step S30:

[0063] Take two semi-cured sheets and attach a reverse cover film to one side of the area corresponding to the bending area to form a first semi-cured layer 50A and a second semi-cured layer 50B, which are used to participate in the stacking and pressing process in the subsequent process and serve as the adhesive layer.

[0064] In this embodiment, the side of the reverse cover film 5010 adjacent to the rigid area 100B is retracted into the bending area 1010A, while the other sides extend into the ineffective area 100B. By retracting into the bending area 1010A, the structure of the reverse cover film 5010 extending into the rigid area 100B is effectively avoided. After subsequent pressing, the reverse cover film 5010 is pressed and fixed, increasing the difficulty of removing the reverse cover film 5010. Furthermore, by extending the other sides into the ineffective area 100B, a covering and protective effect is formed on the connecting copper pattern 1010, preventing the connecting copper pattern 1010 from forming an adhesive effect with the first semi-cured layer 50A and the second semi-cured layer 50B during the pressing process, which would be detrimental to the subsequent peeling process.

[0065] Please refer to it again. Figure 8 And see Figure 9 , Figure 9 This is a schematic diagram of the cross-sectional structure of the press plate.

[0066] Step S40:

[0067] First rigid core plate 60A and second rigid core plate 60B are fabricated. The first rigid core plate 60A, the first semi-cured layer 50A, the intermediate core plate 40, the second semi-cured layer 50B and the second rigid core plate 60B are stacked from top to bottom to form a stacked structure 200. Then, they are pressed together to form a pressed plate 70, with the reverse cover film 5010 facing the intermediate core plate 40. Since the depth of the subsequent peeling process is from the plate surface to the reverse cover film 5010, the inertia and peelability of the reverse cover film 5010 provide a processing basis for easy peeling in the subsequent peeling process. On the other hand, it forms a protective effect on the plate surface, reducing the possible contamination of the plate surface by debris generated during peeling, which is beneficial to the etching process in the subsequent process.

[0068] Please see Figure 10 and Figure 11 , Figure 10 A schematic diagram of the planar structure for uncovering the rigid-flex plate; Figure 11 for Figure 10 A schematic diagram of the AA section structure.

[0069] Step S50:

[0070] The bending area 1010A of the press plate 70 is peeled off to expose the connecting copper pattern 1010, providing a processing basis for subsequent etching, and the whole is formed into a peeled rigid flexible plate 80.

[0071] In one embodiment, the uncovering process involves controlling the depth of the bending area 1010A of the press plate 70 to the depth of the plate surface to the reverse cover film 5010.

[0072] Please see Figure 12 , Figure 12 This is a schematic diagram of the cross-sectional structure of a rigid-flexible plate.

[0073] Step S60:

[0074] The rigid-flex plate 80 is etched, and the rigid area 100B is shaped to form the rigid-flex plate 90.

[0075] Since the connecting copper pattern 1010 serves to connect the cover film with the effective area 100A and the bending area 1010A, and assists in the positioning of the cover film, after being exposed by the cover removal process, the connecting copper pattern 1010 is etched away in this process. In addition, the edge of the bending area 1010A has been formed by laser through groove 4010 in the previous process, that is, the bending area 1010A has been formed. Therefore, only the rigid area 1010B needs to be formed to form the rigid-flexible bonded plate 90.

[0076] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for manufacturing a wire harness-type high aspect ratio rigid-flex plate, characterized in that, The rigid-flexible plate is designed with forming lines, the area within the forming lines is the effective area, and the remaining area is the ineffective area. The effective area includes a bending area and a rigid area. The manufacturing method includes the following steps: S10: Take a first cover film with a copper layer attached to its surface. Make a first cover film window pattern on the first cover film corresponding to the rigid area. Then make a first circuit pattern on the copper layer to form a copper pattern board. Creating the first circuit pattern includes creating a connecting copper pattern in the bending area, the connecting copper pattern spanning the bending area and extending into the invalid area, the portion extending into the invalid area being the extension length; The process of creating the first cover film window pattern includes creating a connection position window pattern on the first cover film corresponding to the connection copper pattern, wherein the connection position window pattern extends from the edge of the bending area to the invalid area. The width of the connection window pattern is greater than or equal to the width of the connection copper pattern, and the length of the connection window pattern is less than the extension length. S20: Take another double-sided flexible copper-clad board, make a second circuit pattern to form a core board pattern, and mill micro-grooves at the edge of the bending area and in the area corresponding to the connecting copper pattern to form a micro-groove board. The microgroove plate is then stacked and pressed between the two copper pattern plates, with the connecting copper pattern facing away from the microgroove plate. Next, mill through slots are cut into the edges of the bending area, excluding the connecting copper pattern, to form an intermediate core board; S30: Take two layers of semi-cured sheets and attach a reverse cover film to one side of the area corresponding to the bending area to form a first semi-cured layer and a second semi-cured layer respectively. S40: Fabricate a first rigid core board and a second rigid core board, and stack the first rigid core board, the first semi-cured layer, the intermediate core board, the second semi-cured layer and the second rigid core board from top to bottom to form a stacked structure, and then press them together to form a press-fit plate; The reverse cover film faces the intermediate core plate; S50: The bending area of ​​the press plate is peeled off to expose the connecting copper pattern, forming a peeled rigid flexible plate; S60: The cover rigid-flex plate is etched, and the rigid area is shaped to form the rigid-flex plate.

2. The method for manufacturing a wire harness-type high aspect ratio rigid-flex plate as described in claim 1, characterized in that, The copper pattern board is fabricated by punching the first cover film to create a windowed pattern, which includes the connection windowed pattern, to form a windowed cover film. A copper layer is then attached to the first side with a micro-adhesive film layer. The second side is then pressed against the windowed cover film. The micro-adhesive film layer is removed to create the first circuit pattern and form the copper pattern board.

3. The method for manufacturing a wire harness-type high aspect ratio rigid-flex plate as described in claim 1, characterized in that, To create the connection point window pattern, the first cover film at the location of the connection point window pattern is laser-ablated.

4. The method for manufacturing a wire harness-type high aspect ratio rigid-flex plate as described in claim 1, characterized in that, Fabricating the copper pattern board includes creating a first grid copper pattern in the region of the invalid area.

5. The method for manufacturing a wire harness-type high aspect ratio rigid-flex plate as described in claim 1, characterized in that, Fabricating the intermediate core board includes creating a second grid copper pattern in the region of the invalid area.

6. The method for manufacturing a wire harness-type high aspect ratio rigid-flex plate as described in claim 1, characterized in that, The side of the reverse covering film adjacent to the rigid area is recessed inwards corresponding to the bending area, while the other sides extend into the ineffective area.

7. The method for manufacturing a wire harness-type high aspect ratio rigid-flex plate as described in claim 1, characterized in that, The peeling process involves performing controlled-depth milling on the bending area of ​​the pressed plate, with the controlled-depth milling depth extending from the plate surface to the reverse cover film.

8. The method for manufacturing a wire harness-type high aspect ratio rigid-flex plate as described in claim 1, characterized in that, The length of the connection window pattern is less than the extension length of the connection copper pattern by a distance of 25 μm to 105 μm.

9. The method for manufacturing a wire harness-type high aspect ratio rigid-flex plate as described in claim 1, characterized in that, The milled microgrooves are cut using laser milling.

10. The method for manufacturing a wire harness-type high aspect ratio rigid-flex plate as described in claim 9, characterized in that, The milling width of the microgroove is 5μm to 25μm.

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