Manufacturing method of thick-copper large-current-carrying high-flexibility hollowed-out circuit rigid-flexible combined board

Abstract

The invention discloses a manufacturing method of a thick-copper large-current-carrying high-flexibility hollowed-out circuit rigid-flexible combined board. The manufacturing method comprises the following steps: manufacturing a rigid core board of which the surface is provided with a copper layer and a prepreg; taking a flexible copper-clad plate to manufacture a first circuit pattern, and then manufacturing a first window corresponding to the flexible area to form a flexible plate; a single-face flexible copper-clad plate is taken, a second circuit pattern is manufactured corresponding to the first window, cutting is conducted corresponding to the flexible area, and then the single-face flexible copper-clad plate and the flexible plate are pressed to form a flexible core plate; the rigid core board and the flexible core board are stacked and laminated, then uncovering processing is carried out, laser milling is carried out on the second circuit pattern, and the rigid-flexible combined board is formed; low-flow glue prepregs are arranged among the layers, so that the risk of insufficient glue filling or uneven plate surface is reduced; a second circuit pattern is manufactured by using a single-sided flexible copper-clad plate, and the second circuit pattern and the first circuit pattern are designed in a staggered manner, so that an effect of adjusting colloid flow is achieved, and effective wrapping of the first circuit pattern is formed; and a hollow circuit is formed through laser milling, so that the bending performance of the flexible area is improved.

Description

Technical Field

[0001] The invention relates to the field of printed circuit board manufacturing, in particular to the field of flexible circuit board manufacturing, and more particularly to a method for manufacturing a thick copper, large current-carrying, highly flexible hollow circuit rigid-flexible board. Background Art

[0002] With the development of intelligent connected cars, charging piles and low-altitude aircraft, higher requirements are put forward for the circuit boards used in them, which not only need to have flexible assembly characteristics, but also be able to carry large currents or instantaneous large currents. To this end, a thick copper rigid-flexible board is designed, in which the thick copper line ensures high current carrying capacity and excellent heat dissipation performance, while the rigid-flexible design combines the support stability of the rigid board with the flexible assembly advantages of the flexible board.

[0003] Typically, this type of thick copper rigid-flex PCB is produced using traditional manufacturing methods, including making rigid core boards and flexible core boards, stacking and pressing, followed by processing of surface circuits and solder mask layers to ultimately form a rigid-flex PCB.

[0004] However, the traditional processing methods have the following disadvantages: (1) In order to ensure sufficient filling between thick copper layers and good interlayer bonding strength, it is necessary to use high pressure, high temperature and long-term pressing parameters, but this often leads to unevenness on the board surface, affecting the interlayer thickness accuracy and the quality of the surface circuit; if the pressing parameters are reduced, it may cause insufficient filling and decreased interlayer bonding strength, and there is a risk of delamination or even explosion; (2) For the flexible area, if a larger pressing parameter is used to fill the line gap, the surface unevenness will increase; if a thicker covering film is used to avoid the above problems, the bending ability of the flexible area will be reduced, which may easily cause "dead bends" or rebounds during assembly or use, thereby affecting the quality of electrical signal transmission and the overall reliability of the circuit board.

[0005] Therefore, in order to solve the above-mentioned problems, it is necessary to provide a method for manufacturing a thick copper, large current-carrying, and highly flexible hollow circuit rigid-flexible board. Summary of the invention

[0006] The present invention aims to solve the problem that the rigid-flexible board in the prior art cannot simultaneously meet the comprehensive problems of thick copper, large current carrying requirements and high flexibility, and proposes a method for manufacturing a thick copper, large current carrying, high flexibility hollow circuit rigid-flexible board, wherein the rigid-flexible board includes a rigid area and a flexible area, and the manufacturing method includes the following steps: S10: After the previous process, a rigid core board is formed with a copper layer on one side and a prepreg on the other side; S20: Take a flexible copper-clad laminate, make a first circuit pattern, and then make a first window on the insulating dielectric layer of the flexible copper-clad laminate corresponding to the flexible area, so that the flexible copper-clad laminate forms a flexible board; S30: taking a single-sided flexible copper-clad laminate, making a second circuit pattern corresponding to the first opening, cutting it corresponding to the flexible area to form a pattern covering film, and then aligning and pressing the pattern covering film with the flexible board to form a flexible core board; The first circuit pattern and the second circuit pattern are offset from each other; S40: stacking and pressing the rigid core board and the flexible core board to form a pressed board; S50: performing a cover-lifting process on the flexible area of ​​the laminated board to expose the flexible core board, and then performing laser milling and molding corresponding to the second circuit pattern to form the rigid-flexible board.

[0007] Furthermore, the forming of the rigid core board also includes making a blind groove on the edge of the prepreg corresponding to the flexible area.

[0008] Furthermore, the rigid core board is formed by taking copper foil, a low-flow adhesive prepreg and a single-sided copper clad laminate, stacking and pressing them in sequence, and then etching the surface copper layer of the single-sided copper clad laminate to form the rigid core board.

[0009] Furthermore, the surface copper layer is a thin copper foil with a thickness of 5 μm to 10 μm.

[0010] Furthermore, the insulating dielectric layer of the single-sided copper clad laminate is a high-flow adhesive prepreg.

[0011] Furthermore, the first window is divided into a plurality of first sub-windows by a plurality of the first circuit patterns.

[0012] Furthermore, the making of the second circuit pattern is to make a plurality of second sub-circuit patterns corresponding to each of the first sub-windows.

[0013] Furthermore, one side of the second sub-circuit pattern is smaller than the corresponding first sub-window.

[0014] Furthermore, the laser milling area corresponds to the second circuit pattern and is tangent to the edge of the flexible area.

[0015] Furthermore, the length of the region of the pattern covering film facing the rigid region and corresponding to the second circuit pattern is less than or equal to the length of the flexible region.

[0016] The technical solution of the present invention first processes the rigid core board separately, and sets a low-flow glue prepreg between the layers, and further uses a single-sided copper clad laminate containing a high-flow glue prepreg, and combines the high adhesion performance of the high-flow glue prepreg with the filling performance of the low-flow glue prepreg to ensure that the gaps between the thick copper circuits can be effectively filled under high temperature and high pressure conditions, reducing the risk of insufficient glue filling or uneven board surface, and solving the problems of insufficient glue filling and decreased interlayer bonding force in the prior art; by using a single-sided flexible copper clad laminate instead of a covering film to make a pattern, and the staggered design setting of the second circuit pattern and the first circuit pattern, it plays a role in adjusting the flow of the colloid, forming a first circuit pattern The effective wrapping improves the bending performance of the flexible area, which solves the problem that the use of thicker covering films in the prior art will reduce the bending ability of the flexible area, which is easy to cause "dead folding" or rebound during assembly or use. On the other hand, after the first circuit pattern is wrapped, it can effectively prevent the side of the hollow circuit copper surface from being exposed, thereby preventing problems such as oxidation and aging of the circuit copper surface during application; finally, the second circuit pattern used as auxiliary pressing is removed by laser cutting technology, thereby forming a hollow first circuit pattern in the flexible area, reducing the constraints of the material layer in the planar direction, thereby improving the bending performance of the flexible area, and the front and rear processes cooperate with each other to form an effective technical correlation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of the process flow of an embodiment of the present invention; Figure 2 A schematic plan view of a rigid core plate according to an embodiment of the present invention; Figure 3 for Figure 2 AA cross-sectional diagram of ; Figure 4 is a schematic plan view of a flexible board according to an embodiment of the present invention; Figure 5 for Figure 4 BB cross-section diagram; Figure 6 is a schematic cross-sectional view of a stacked structure according to an embodiment of the present invention; Figure 7 A schematic plan view of a flexible core board according to an embodiment of the present invention; Figure 8 for Figure 7Schematic diagram of CC cross section; Fig. 9 is a schematic cross-sectional view of a pressed plate according to an embodiment of the present invention; Fig.10 It is a cross-sectional schematic diagram of a cover plate according to an embodiment of the present invention; Fig.11 A schematic plan view of a milling plate according to an embodiment of the present invention; Fig.12 for Fig.11 DD cross-sectional diagram; Fig.13 It is a schematic plan view of a rigid-flex board according to an embodiment of the present invention.

[0019] Explanation of the accompanying numbers: 10-rigid core board; 1010-blind groove; 20-flexible board; 2010-first circuit pattern; 2020-first window; 2030-insulating dielectric layer of flexible copper clad laminate; 30-stacked structure; 3010-graphic covering film; 3010a-second circuit pattern; 3010b-glue layer of single-sided flexible copper clad laminate; 3010c-PI layer of single-sided flexible copper clad laminate; 40-flexible core board; 50-pressed board; 60-cover board; 70-milled board; 80-rigid-flexible board.

[0020] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, inside, outside...) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0023] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0024] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] See also Figure 1 , Figure 1 Schematic diagram of the process flow of an embodiment of the present invention.

[0026] The manufacturing process of the embodiment of the present invention includes using Figure 1 The following will implement the various steps in the process Figure 1 Each step in the process is further explained step by step.

[0027] The rigid-flex board according to the embodiment of the present invention includes a rigid area and a flexible area.

[0028] See also Figure 2 and Figure 3 , Figure 2 A schematic plan view of a rigid core plate according to an embodiment of the present invention; Figure 3 for Figure 2 Schematic diagram of the AA section.

[0029] Step S10: After the previous processing, a rigid core board 10 is formed with a copper layer on one side and a prepreg on the other side.

[0030] One side of the rigid core board 10 is a copper layer to provide an electrical connection path, and the other side is a prepreg that can flow and fill the gaps when heated and pressurized, providing a processing basis for subsequent lamination to form a solid bonding layer.

[0031] As an optional implementation, the rigid core board 10 is formed by taking copper foil, a low-flow adhesive semi-cured sheet and a single-sided copper clad laminate, stacking and pressing them in sequence, and then etching the surface copper layer of the single-sided copper clad laminate to form the rigid core board 10.

[0032] First, a rigid core board 10 is formed by separate processing, and a low-flow adhesive semi-cured sheet is set between the layers for interlayer bonding to ensure that the gaps between the thick copper circuits can be effectively filled under high temperature and high pressure conditions, reducing the risk of insufficient adhesive filling or uneven board surface. The copper foil and the single-sided copper clad laminate form upper and lower copper layers, which are then pressed together in a subsequent process to form a rigid core board 10, providing a pressing basis for using larger pressing parameters.

[0033] During this lamination process, the low-flow prepreg can ensure close bonding between the board layers while avoiding glue overflow caused by excessive glue.

[0034] It is worth noting that a single-sided copper clad laminate is set to participate in the lamination in order to form a corresponding effect with the upper and lower surface materials with the copper foil. The use of copper foil can improve the colloid fluidity and filling properties inside the board during the lamination process, improve the circuit gap filling effect and interlayer bonding strength, and the copper foil on the lower surface does not need to be retained later. Therefore, the surface copper layer of the single-sided copper clad laminate is set to a thin copper foil, which makes it easier to control the accuracy in the subsequent process, reduces the workload of etching away the excess copper layer, and improves production efficiency.

[0035] Optionally, the thin copper foil has a thickness of 5 μm to 10 μm.

[0036] Furthermore, the insulating dielectric layer of the single-sided copper clad laminate is a high-flow adhesive prepreg.

[0037] The fluidity and filling properties of the colloid during the lamination process are improved, providing better adhesion conditions for subsequent lamination with the flexible board 20 (etching off the thin copper foil to expose the high-flow adhesive semi-cured sheet), thereby ensuring good bonding between the rigid core board 10 and the flexible board 20.

[0038] In this embodiment, forming the rigid core board 10 further includes making a blind groove 1010 on the edge of the prepreg corresponding to the flexible area.

[0039] It is convenient for the subsequent uncovering process, that is, removing the rigid board layer on the flexible area to expose the flexible layer below, ensuring that no unnecessary damage is caused to the flexible area during the manufacturing process, while ensuring the structural integrity and functional performance of the final product.

[0040] Optionally, the blind groove 1010 is made by mechanical milling of the blind groove 1010 or laser milling of the blind groove 1010 , and preferably, the laser blind groove 1010 is used.

[0041] Optionally, the blind groove 1010 has a depth of 0.05 mm to 0.5 mm and a width of 0.05 mm to 0.2 mm.

[0042] See also Figure 4 and Figure 5 , Figure 4 is a schematic plan view of a flexible board according to an embodiment of the present invention; Figure 5 for Figure 4 Schematic diagram of BB cross section.

[0043] Step S20: A flexible copper clad laminate is taken to make a first circuit pattern 2010, and then a first window 2020 is made on the insulating dielectric layer 2030 of the flexible copper clad laminate corresponding to the flexible area, so that the flexible copper clad laminate forms a flexible board 20.

[0044] The first opening 2020 is formed in that a covering film needs to be attached to the flexible area in the subsequent process to form a hollow circuit structure in which the flexible area is covered by the covering film. Therefore, the covering film is laser cut. When the covering film is attached to the formed hollow circuit, the middle insulating layer is removed, and the colloid can directly "wrap" the first circuit pattern 2010, forming a "colloid-to-colloid" adhesion mode, thereby enhancing the bonding force between the colloid and the first circuit pattern 2010 and improving the overall stability of the flexible board 20.

[0045] Furthermore, the first circuit pattern 2010 is hollowed out to reduce the depth of subsequent laser cutting, thereby reducing laser energy, avoiding deformation of the flexible zone due to excessive ablation, and reducing the amount of carbon powder generated by subsequent laser cutting, preventing problems such as short circuits and pollution caused by carbon powder.

[0046] This method reduces the constraints of the material layer in the plane direction of the flexible area, so that the flexible area has better bending performance and ensures good electrical connectivity and mechanical strength.

[0047] In this embodiment, the first window 2020 is divided into a plurality of first sub-windows by a plurality of first circuit patterns 2010, and a plurality of second sub-circuit patterns are produced corresponding to each first sub-window.

[0048] Furthermore, a single side of the second sub-circuit pattern is smaller than the corresponding first sub-window.

[0049] On the one hand, it provides an allowable error distance for the laser cutting of the second circuit pattern 3010a in the subsequent process to avoid slight deviations during laser milling, which may affect the functionality of the circuit or cause short circuits. On the other hand, the first circuit pattern 2010 divides the single first window 2020 into multiple first sub-windows, which cooperate with the laser milling in the subsequent process to form an independent hollow first circuit pattern 2010 wrapped by a covering film in the flexible area, thereby reducing the material coverage of the flexible area on the plane, thereby improving the flexural performance of the flexible area.

[0050] Optionally, a single side of the second sub-circuit pattern is 20 μm to 70 μm smaller than the corresponding first sub-window.

[0051] See also Figure 6 , Figure 7 and Figure 8 , Figure 6 is a schematic cross-sectional view of a stacked structure according to an embodiment of the present invention; Figure 7 A schematic plan view of a flexible core board according to an embodiment of the present invention; Figure 8 for Figure 7 Schematic diagram of CC cross section.

[0052] Step S30: Take a single-sided flexible copper clad laminate, make a second circuit pattern 3010a corresponding to the first window 20, and cut it corresponding to the flexible area to form a pattern covering film 3010, then align the pattern covering film 3010 with the flexible board 20 to form a stacked structure 30, and then press it together to form a flexible core board 40 as a whole; the first circuit pattern 2010 and the second circuit pattern 3010a are offset from each other.

[0053] By adopting a single-sided flexible copper clad laminate (including an adhesive layer 3010b of the single-sided flexible copper clad laminate and a PI layer 3010c of the single-sided flexible copper clad laminate), a second circuit pattern 3010a is manufactured to form a pattern covering film 3010 to replace an ordinary covering film. During the lamination process, since the area corresponding to the position of the second circuit pattern 3010a has been hollowed out, the adhesive layer 3010b of the single-sided flexible copper clad laminate can bypass the second circuit pattern 3010a and flow into the hollow position that needs to be filled, thereby forming an effective wrapping of the first circuit pattern 2010, thereby improving the stability and reliability of the overall structure. That is, the second circuit pattern 3010a uses the second circuit pattern 3010a located above the stacked structure 30 and the second circuit pattern 3010a located below the stacked structure 30 to form a "copper to copper" setting, thereby enhancing the force uniformity during lamination.

[0054] Furthermore, during the lamination process, the second circuit pattern 3010a can fix the first circuit pattern 2010 to prevent it from being displaced, skewed or deformed, thereby ensuring the precise layout and electrical performance of the first circuit pattern 2010. In view of the fact that this part of the second circuit pattern 3010a will eventually need to be removed by laser cutting or the like, the "copper to copper" setting is only used as an auxiliary means in the processing process and will not have a negative impact on the finished board.

[0055] Furthermore, the length of the region of the pattern cover film 3010 facing the rigid region and corresponding to the second circuit pattern 3010a is less than or equal to that of the flexible region.

[0056] Taking into account the functional requirements of different areas, for the first circuit graphic 2010 part, the covering film needs to extend into the rigid board area to ensure the connection strength; and for the first window 2020 area (that is, the part to be hollowed out later), if the covering film also extends into the rigid board area, it may affect the bonding force between the rigid boards. Therefore, shortening the length of this part of the graphic covering film 3010 helps to improve the bonding effect between the rigid boards, thereby improving the mechanical strength and stability of the entire circuit board.

[0057] Optionally, the size of is smaller than is 50 μm to 1.5 mm.

[0058] See also Fig. 9 , Fig. 9 It is a schematic cross-sectional view of a pressed plate according to an embodiment of the present invention.

[0059] Step S40: The rigid core board 10 and the flexible core board 40 are stacked and laminated to form a laminated board 50 .

[0060] See also Fig.10 , Fig.11 , Fig.12 and Fig.13 , Fig.10 It is a cross-sectional schematic diagram of a cover plate according to an embodiment of the present invention; Fig.11 A schematic plan view of a milling plate according to an embodiment of the present invention; Fig.12 for Fig.11 DD cross-sectional diagram; Fig.13 It is a schematic plan view of a rigid-flex board according to an embodiment of the present invention.

[0061] Step S50: The flexible area of ​​the laminated plate 50 is uncovered to form a uncovering plate 60 to expose the flexible core plate 40 , and then laser milling is performed corresponding to the second circuit pattern 3010a to form a milling plate 70 , which is then reshaped to form a rigid-flexible board 80 .

[0062] In this embodiment, the area cut by laser milling corresponds to the second circuit pattern 3010a and is tangent to the edge of the flexible area.

[0063] That is, the second circuit pattern 3010a as the auxiliary circuit is milled off, and the edge facing the rigid area is the long side cut by laser milling, and the long side coincides with the rigid-flex junction line to form a hollow structure in which multiple first sub-circuits connect adjacent rigid areas.

[0064] It is worth noting that the width of the laser milling is greater than the width of the second circuit pattern 3010a. On the one hand, the previous process performed pre-reduction processing when making the second circuit pattern 3010a, so there is a certain gap between the second circuit pattern 3010a and the first circuit pattern 2010, reserving enough space for laser cutting. On the other hand, due to the lamination process, the second circuit pattern 3010a will produce certain offset and deformation errors. Therefore, widening the width of the laser milling can ensure that the laser cutting cuts the covering film and the glue layer, and ensures that the cutting of the second circuit pattern 3010a can fall completely within the cutting range.

[0065] Preferably, the width of the laser milling is greater than the width of the second circuit pattern 3010a, preferably greater than 20 μm to 50 μm. Further, the width of the laser milling is smaller than the width of the first sub-window.

[0066] That is, the milling line in the width direction of the laser milling is located between the first sub-window and the corresponding second circuit pattern 3010a, ensuring that the edges of the second circuit pattern 3010a "wrapped" by the glue layer 3010b of the single-sided flexible copper clad laminate and the PI layer 3010c of the single-sided flexible copper clad laminate will not be cracked by the laser milling.

[0067] During the lamination process of the multilayer board, the influence of factors such as temperature and pressure may cause offset or deformation between the layers. If the error is not properly compensated, it may lead to inaccurate laser cutting, which in turn affects the function and reliability of the circuit. Therefore, by adding an additional width of 20μm to 50μm, these errors can be absorbed to a certain extent, ensuring that even if these changes occur, the second circuit pattern 3010a can still fall accurately within the laser cutting range to ensure the cutting quality.

[0068] Although laser cutting has high precision, there is a certain error range in actual operation. Reserving additional gaps can provide a buffer space for these possible errors and achieve precise cutting effects. In addition to cutting the second circuit pattern 3010a, it is also necessary to remove the covering film and glue layer on the corresponding area. Therefore, appropriate gaps help the laser penetrate these material layers more thoroughly to ensure the formation of a clear and complete hollow structure.

[0069] It is worth noting that the present invention is aimed at processing the case where the line gap in the flexible area is relatively large (preferably the gap is above 100μm). For the case where the line gap in the flexible area is relatively dense, the pressing and shrinkage may affect the actual accuracy and the laser cutting accuracy may be insufficient.

[0070] In this embodiment, the size correlation relationship of the hollow area is based on the first sub-window, wherein the second sub-circuit pattern is smaller than the corresponding first sub-window on one side, wherein the graphic covering film 3010 faces the rigid area and corresponds to the area of ​​the second circuit pattern 3010a, the length is less than or equal to the flexible area, and the laser milling area corresponds to the second circuit pattern 3010a and is tangent to the edge of the flexible area. Furthermore, the width of the laser milling is smaller than the width of the first sub-window; the overall size correlation relationship of the processing process of the first sub-window position is formed to ensure that the second circuit pattern 3010a is effectively "wrapped" after processing.

[0071] This embodiment combines the high adhesion performance of the high-flow glue semi-cured sheet with the filling performance of the low-flow glue semi-cured sheet, on the one hand, ensuring that the gaps between the thick copper circuits can be effectively filled under high temperature and high pressure conditions, reducing the risk of insufficient glue filling or uneven board surface; more importantly, a good bonding layer is formed in the previous process, which provides a more effective covering ability for the "wrapping" glue filling of the hollow circuit in the subsequent process of pressing; then a single-sided flexible copper clad laminate is used instead of a covering film to produce a second circuit pattern 3010a that performs an auxiliary pressing effect. The second circuit pattern 3010a is designed to adjust the flow of the colloid through a misaligned setting with the first circuit pattern 2010, thereby forming an effective wrapping of the first circuit pattern 2010 and improving the bending performance of the flexible area. Furthermore, after the first circuit pattern 2010 is effectively wrapped, it can effectively prevent the side of the copper surface of the hollow circuit from being exposed, and prevent the risks of oxidation and aging of the copper surface of the circuit during the application process, forming a front-to-back correlation relationship between the pressing effect as a whole, and the pressing of the previous process affects the smooth glue filling effect of the hollow circuit in the subsequent process.

[0072] It is worth noting that due to the precise design and processing of flexible circuit boards, the actual processing structure and the thickness of each layer, line width and other dimensions are all at the micron level. If the drawings are made according to the enlarged ratio of the actual structure, the illustrations will be unclear. Therefore, in order to more clearly and intuitively represent the implementation process of the manufacturing method of this embodiment, the drawings of this embodiment are all schematic diagrams that enlarge the technical features, which do not represent the size of the actual structure, nor are they enlarged drawings of the actual structure in proportion.

[0073] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing a thick copper, high current carrying, high flexibility hollow circuit rigid-flexible board, the rigid-flexible board comprising a rigid area and a flexible area, characterized in that: The production method comprises the following steps: S10: After the previous process, a rigid core board is formed with a copper layer on one side and a prepreg on the other side; S20: Take a flexible copper-clad laminate, make a first circuit pattern, and then make a first window on the insulating dielectric layer of the flexible copper-clad laminate corresponding to the flexible area, so that the flexible copper-clad laminate forms a flexible board; S30: taking a single-sided flexible copper-clad laminate, making a second circuit pattern corresponding to the first opening, cutting it corresponding to the flexible area to form a pattern covering film, and then aligning and pressing the pattern covering film with the flexible board to form a flexible core board; The first circuit pattern and the second circuit pattern are offset from each other; S40: stacking and pressing the rigid core board and the flexible core board to form a pressed board; S50: performing a cover-lifting process on the flexible area of ​​the laminated board to expose the flexible core board, and then performing laser milling and molding corresponding to the second circuit pattern to form the rigid-flexible board.

2. The method for manufacturing a thick copper, large current-carrying, high-flexibility hollow circuit rigid-flexible board according to claim 1, characterized in that: The forming of the rigid core board also includes making a blind groove on the edge of the prepreg corresponding to the flexible area.

3. The method for manufacturing a thick copper, large current-carrying, high-flexibility hollow circuit rigid-flexible board according to claim 1, characterized in that: The rigid core board is formed by taking copper foil, low-flow adhesive prepreg and single-sided copper clad laminate, stacking and pressing them in sequence, and then etching the surface copper layer of the single-sided copper clad laminate to form the rigid core board.

4. The method for manufacturing a thick copper, large current-carrying, high-flexibility hollow circuit rigid-flexible board according to claim 3, characterized in that: The surface copper layer is a thin copper foil with a thickness of 5 μm to 10 μm.

5. The method for manufacturing a thick copper, large current-carrying, high-flexibility hollow circuit rigid-flexible board according to claim 4, characterized in that: The insulating dielectric layer of the single-sided copper clad laminate is a high-flow adhesive prepreg.

6. The method for manufacturing a thick copper, large current-carrying, high-flexibility hollow circuit rigid-flexible board according to claim 1, characterized in that: The first window is divided into a plurality of first sub-windows by a plurality of the first line patterns.

7. The method for manufacturing a thick copper, large current-carrying, high-flexibility hollow circuit rigid-flexible board according to claim 6, characterized in that: The step of making the second circuit pattern is to make a plurality of second sub-circuit patterns corresponding to each of the first sub-windows.

8. The method for manufacturing a thick copper, large current-carrying, high-flexibility hollow circuit rigid-flexible board according to claim 7, characterized in that: The second sub-circuit pattern is smaller than the corresponding first sub-window on one side.

9. A method for manufacturing a thick copper, large current-carrying, high-flexibility hollow circuit rigid-flexible board as claimed in claim 1 or 8, characterized in that: The laser milling area corresponds to the second circuit pattern and is tangent to the edge of the flexible area.

10. A method for manufacturing a thick copper, large current-carrying, high-flexibility hollow circuit rigid-flexible board as claimed in claim 1 or 8, characterized in that: The pattern covering film faces the rigid area and corresponds to the area of ​​the second circuit pattern, and has a length that is less than or equal to the flexible area.

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