Manufacturing Method of a Voltage-Resistant Flexible Circuit Board for a New Energy Vehicle

Abstract

The present invention discloses a manufacturing method of a voltage-resistant flexible circuit board for new energy vehicles, including the steps of: taking copper foil and a single-sided flexible copper clad laminate having a laminated structure of a PI layer, an adhesive layer, and a copper layer in sequence, laminating and pressing the copper foil and the single-sided flexible copper clad laminate to form a flexible pressed board, making circuits on the copper foil of the flexible pressed board and removing the copper layer to form a flexible core board, taking a first cover film and a second cover film, laminating and pressing the first cover film, the flexible core board, and the second cover film in sequence to form a pressed board, and attaching a reinforcement to the pressed board to form a flexible circuit board; manufacturing a single-sided copper clad laminate without an adhesive layer by a transfer method, which has higher voltage-resistant performance, designing a grounding circuit to be connected to the reinforcement through a conductive adhesive to realize a grounding circuit network, avoiding the low reliability and poor applicability of connecting the grounding circuit to a grounding module by welding; the overall formation of a flow-based manufacturing method has good coordination.

Description

Technical Field

[0001] The present invention relates to the field of printed circuit board processing, particularly to the field of flexible circuit board processing, and more particularly to a manufacturing method for a voltage-resistant flexible circuit board for new energy vehicles. Background Art

[0002] With the continuous development of new energy vehicles, the intelligent, multi-functional, and networking performance has been continuously improved. Some control units are required to have high voltage resistance performance and grounding performance at the same time. Due to the miniaturization development of the control unit module, it is required that the internal circuit board realizes flexible distribution in a smaller space. Therefore, a flexible circuit board with a single-layer copper line is used to replace the traditional connecting wire harness to achieve flexible installation and good voltage resistance and grounding performance.

[0003] Currently, for this type of flexible circuit board, it is manufactured by a traditional manufacturing method, that is, a single-sided flexible copper clad laminate with a relatively thick copper thickness is taken to manufacture a core board to form a voltage-resistant line and a grounding line, and then it is stacked and laminated with other layers, and after post-process processing, a flexible circuit board is formed; a relatively thick copper layer line is used to achieve high voltage resistance performance, and the grounding line is welded to the grounding component of the electronic module through subsequent welding to form good grounding.

[0004] However, this manufacturing method mainly has the problem that for a general single-sided flexible copper clad laminate, there is an adhesive layer between the copper layer and the polyimide material layer, and the laminated cover film layer also has an adhesive layer. After lamination, the circuit copper layer is wrapped by the upper and lower adhesive layers. The adhesive layer is usually an epoxy resin adhesive layer or an acrylic adhesive layer, and its glass transition temperature is relatively lower than that of the polyimide material. Although it is more conducive to the processing of processes such as lamination of flexible circuit board products and reduces the processing difficulty, in the application process of the flexible circuit board finished product, it is easy to cause poor voltage resistance performance, and problems such as circuit burnout are likely to occur after long-term use; and the grounding line is grounded by welding, which has high requirements for subsequent processing, and the flexible circuit board is relatively soft, and the welding difficulty is large, and a high defective rate is likely to occur.

[0005] Based on the above background and problems, a new manufacturing method for improving the voltage resistance performance and grounding performance of flexible circuit boards is needed. Summary of the Invention

[0006] The present invention aims at the problems of insufficient voltage resistance performance, cumbersome grounding design and grounding process in a flexible circuit board with a voltage-resistant line and a grounding line, and provides a manufacturing method for a voltage-resistant flexible circuit board for new energy vehicles. The manufacturing method includes the following steps:

[0007] S10: Take a copper foil, and take a single-sided flexible copper clad laminate with a laminated structure of a polyimide layer, an adhesive layer, and a copper layer in sequence. Stack and laminate the copper foil and the single-sided flexible copper clad laminate, and press them to form a flexible laminate.

[0008] S20: Fabricate circuits on the copper foil of the flexible pressing plate and remove the copper layer to form a flexible core board.

[0009] S30: Take a first cover film and a second cover film, stack and press the first cover film, the flexible core board, and the second cover film in sequence to form a pressed board.

[0010] S40: Stick a reinforcement on the pressed board to form the flexible circuit board.

[0011] Further, forming the flexible pressing plate includes: attaching a high-temperature resistant blue glue to one side of the copper foil to form a blue glue copper foil; performing plasma activation treatment on the single-sided flexible copper clad laminate, and then performing chemical activation treatment to form an activated copper clad laminate; stacking the blue glue copper foil and the activated copper clad laminate, with the copper foil facing the polyimide layer, and pressing them to form the flexible pressing plate.

[0012] Further, forming the flexible pressing plate includes: stacking the copper foil and the activated copper clad laminate to form a stacked structure; sequentially arranging release films, cover films, release films, aluminum sheets, and release films from near to far on both sides of the stacked structure to form a layout structure, and pressing them to form the flexible pressing plate.

[0013] Further, forming the flexible core board includes: the circuit fabrication includes fabricating a withstand voltage circuit and a grounding circuit; after removing the copper layer, performing windowing on the adhesive layer and the polyimide layer to form a core board windowing, and overall forming the flexible core board.

[0014] Further, forming the pressed board includes: fabricating a first window on the first cover film to form a first window cover film, with the first window corresponding to the withstand voltage circuit; fabricating a second window on the second cover film to form a second window cover film, with the second window corresponding to the core board windowing; stacking the first window cover film, the flexible core board, and the second window cover film in sequence, with the circuits facing the first window cover film, and pressing them to form the pressed board.

[0015] Further, the single side of the second window is larger than that of the core board windowing.

[0016] Further, forming the flexible circuit board includes: screen-printing conductive adhesive on one side of the second window cover film of the pressed board, then sticking the reinforcement, and pressing them to form the flexible circuit board.

[0017] Further, the reinforcement is a metal material reinforcement.

[0018] Further, the second cover film covers the area of the withstand voltage circuit.

[0019] Further, one side of the reinforcement facing the inside of the flexible circuit board body is a wavy edge.

[0020] The technical solution of the present invention first performs plasma activation and then chemical activation on a single-sided copper clad laminate, applies a high-temperature resistant blue adhesive for copper foil attachment and transfer, and realizes interlayer transfer through a pressing method to fabricate a single-sided copper clad laminate without an adhesive layer, providing a copper clad laminate base with higher withstand voltage performance and increasing a second opening covering film to further improve the withstand voltage performance of the flexible circuit board and increase the covering performance; and by designing a grounding line to be connected to the reinforcement through a conductive adhesive to realize the process of the grounding line network, it avoids the process of connecting the grounding line of the board surface pad to the grounding module through welding, improves the processability and application performance of the grounding line, and the manufacturing process adopts a combination of designing a core board opening and a second opening to realize a good intercommunication process between the conductive adhesive and the grounding line, effectively improving the product reliability; the overall process forms the fabrication of a copper clad laminate without an adhesive, and then introduces a second opening covering film to increase the covering performance and withstand voltage performance. Since the grounding line is designed to be interconnected with the reinforcement through a conductive adhesive, the second opening covering film affects the manufacturing process of the conductive adhesive and the reinforcement. Therefore, designing the core board opening and the second opening provides good opening conditions for the fabrication of the conductive adhesive, further designing the network line to improve the bonding performance between the grounding line and the reinforcement through the conductive adhesive, and realizing the coordination and relevance of the overall processing process to form a good flow-based manufacturing method. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0022] Figure 1 It is the main process flow chart included in the embodiment of the present invention;

[0023] Figure 2 It is a cross-sectional structure schematic diagram of the layout structure of this embodiment;

[0024] Figure 3 It is a cross-sectional structure schematic diagram of the flexible pressing board of this embodiment;

[0025] Figure 4 It is a cross-sectional structure schematic diagram of the flexible board stacked structure of this embodiment;

[0026] Figure 5Schematic cross-sectional structure diagram of the lamination board of this embodiment;

[0027] Figure 6 is Figure 5 Schematic cross-sectional structure diagram of the A-A section of;

[0028] Figure 7 Schematic cross-sectional structure diagram of the flexible circuit board of this embodiment;

[0029] Figure 8 Planar design diagram of the mesh circuit of this embodiment;

[0030] Figure 9 Schematic cross-sectional structure diagram of another lamination board of this embodiment;

[0031] Figure 10 Planar design diagram of the wavy reinforcement of this embodiment;

[0032] Figure 11 is Figure 10 Schematic cross-sectional structure diagram of the B-B section of;

[0033] Figure 12 Schematic cross-sectional structure diagram of another flexible circuit board of this embodiment.

[0034] Explanation of the reference numerals in the drawings: 10, layout structure; 10A, stacked structure; 110, copper foil; 120, high-temperature resistant blue glue; 1020, blue glue copper foil; 130, activated copper clad laminate; 1310, polyimide layer; 1320, adhesive layer; 1330, copper layer; 1410, first release film; 1420, second release film; 1430, third release film; 1440, fourth release film; 1450, fifth release film; 1460, sixth release film; 1510, first covering film; 1520, second covering film; 1610, first aluminum sheet; 1620, second aluminum sheet; 1710, upper table surface of the press; 1720, lower table surface of the press; 20, flexible lamination board; 30, flexible core board; 1110, circuit; 1120, withstand voltage circuit; 1130, grounding circuit; 1140, ordinary circuit; 3110, core board window opening; 40, flexible board stacked structure; 410, first window covering film; 4110, first covering film polyimide layer; 4120, first covering film adhesive layer; 4130, first window opening; 420, second window covering film; 4210, second covering film polyimide layer; 4220, second covering film adhesive layer; 4230, second window opening; 50, lamination board; 510, stepped window opening; 60, flexible circuit board; 610, reinforcement; 620, conductive adhesive; 50A, another lamination board; 420A, partial covering film; 60A, another flexible circuit board; 1130A, mesh circuit; 610A, wavy reinforcement.

[0035] The implementation, functional features, and advantages of the present invention will be further described in conjunction with embodiments with reference to the accompanying drawings. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0037] 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 conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0038] In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0039] 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 ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] Please refer to Figure 1 ; Figure 1 which is the main process flow chart included in the implementation manner of the present invention.

[0041] The manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle according to the implementation manner of the present invention includes Figure 1 the main manufacturing process flow, which will be described in detail in the following steps.

[0042] Please refer to Figure 2 and Figure 3 ; Figure 2 which is a schematic cross-sectional structure diagram of the layout structure of this implementation manner; Figure 3 which is a schematic cross-sectional structure diagram of the flexible pressing plate of this implementation manner.

[0043] Step S10:

[0044] Take a copper foil 110 and a single-sided flexible copper clad laminate having a laminated structure of a polyimide layer 1310, an adhesive layer 1320, and a copper layer 1330 in sequence. Stack and press the copper foil 110 and the single-sided flexible copper clad laminate to form a flexible pressed board 20.

[0045] Further, to form the flexible pressed board 20, it includes: attaching a high-temperature resistant blue adhesive 120 to one side of the copper foil 110 to form a blue adhesive copper foil 1020; performing plasma activation treatment on the single-sided flexible copper clad laminate and then chemical activation treatment to form an activated copper clad laminate 130; stacking the blue adhesive copper foil 1020 and the activated copper clad laminate 130 with the copper foil 110 facing the polyimide layer 1310 and pressing them to form the flexible pressed board 20.

[0046] Optionally, the thickness of the copper foil 110 is 35 μm to 245 μm; a thicker thickness can carry a greater voltage.

[0047] Optionally, the high-temperature resistant temperature of the high-temperature resistant blue adhesive 120 is 160 °C to 220 °C; the high-temperature resistant blue adhesive 120 is an auxiliary transfer film used in the process, which can withstand the high-temperature and high-pressure pressing process of the subsequent process and can be smoothly peeled off.

[0048] Optionally, perform micro-etching or super-roughening treatment on the blue adhesive copper foil 1020 so that during the pressing process of the subsequent process, the copper foil 110 can form a good bonding process and bonding force with the polyimide layer 1310, avoiding problems such as poor pressing, delamination, and voids.

[0049] Optionally, the plasma activation treatment is to perform appropriate treatment using existing plasma equipment and parameters, introducing hydroxyl groups (-OH) on the surface of the polyimide layer 1310 to improve the surface hydrophilicity.

[0050] Optionally, the chemical activation treatment is to perform activation treatment using the activation section of an existing electroless copper plating production line. After plasma activation, it can further improve the activation effect and the surface uniform roughness of the polyimide layer 1310, and improve the surface hydrophilicity and activity.

[0051] The reason for adopting the method of first plasma activation treatment and then chemical activation treatment is that the manufacturing method of this embodiment is to first manufacture a non-adhesive copper clad laminate composed of only the polyimide layer 1310 and the copper foil 110 without the adhesive layer 1320. However, the polyimide layer 1310 has strong inertness and it is generally difficult to bond with the copper foil 110 by pressing. Therefore, the polyimide layer 1310 is fully activated to make its surface have good activity and uniform roughness, effectively improving the pressing bonding force with the copper foil 110, thereby forming the production of a non-adhesive substrate and achieving a non-adhesive copper clad laminate with a good bonding force with an interlayer peel strength > 15 N.

[0052] Further, a flexible pressing plate 20 is formed, including: arranging the copper foil 110 and the activated copper clad laminate 130 in a stacked manner to form a stacked structure 10A; sequentially disposing release films (respectively including the first release film 1410 and the fourth release film 1440 in Figure 2 ), covering films (respectively including the first covering film 1510 and the second covering film 1520 in Figure 2 ), release films (respectively including the second release film 1420 and the fifth release film 1450 in Figure 2 ), aluminum sheets (respectively including the first aluminum sheet 1610 and the second aluminum sheet 1620 in Figure 2 ), and release films (respectively including the third release film 1430 and the sixth release film 1460 in Figure 2 ) on both sides of the stacked structure 10A from near to far to form a typesetting structure 10, placing it between the upper table surface 1710 and the lower table surface 1720 of the press, and performing pressing to form the flexible pressing plate 20.

[0053] The release film can provide good release characteristics after pressing, and is optionally made of polyimide material, polytetrafluoroethylene material; the covering film can provide effective buffering and heat conduction performance during pressing, and is optionally made of materials such as silica gel pads, kraft paper, etc.; the aluminum sheet has good leveling and heat conduction effects.

[0054] In this embodiment, the existing single-sided flexible copper clad laminate and the single-layer copper foil 110 are combined by pressing. Through this film body transfer processing method, a single-sided flexible copper clad laminate without a glue layer 1320 is formed, effectively improving the glass transition temperature, thermochemical properties, and tensile strength of the overall copper clad laminate, reducing the expansion and contraction ratio, improving the comprehensive performance of the material, and effectively avoiding the influence of the glue layer of the existing single-sided copper clad laminate on the withstand voltage performance of the flexible circuit board 60.

[0055] It should be noted that the maximum pressure for pressing the blue glue copper foil 1020 and the activated copper clad laminate 130 in this embodiment is relatively large, optionally 18 kg / cm 2 to 30 kg / cm 2 ; the pressing temperature is relatively high, optionally 160 °C to 220 °C; the pressing time under the condition of the maximum pressure is relatively long, optionally 15 min to 40 min; to ensure the formation of good copper clad laminate material without glue.

[0056] Please refer to Figure 4 ; Figure 4 which is a schematic cross-sectional structure diagram of the flexible plate stacked structure of this embodiment.

[0057] Step S20:

[0058] Peel off the high-temperature resistant blue glue 120, make a circuit 1110 on the copper foil 110 of the flexible pressing plate 20, and remove the copper layer 1330 to form a flexible core board 30.

[0059] Further, a flexible core board 30 is formed, including: fabricating circuit lines 1110 including fabricating voltage-resistant circuit lines 1120 and fabricating grounding circuit lines 1130, and further including ordinary circuit lines 1140; after removing the copper layer 1330, openings are made in the adhesive layer 1320 and the polyimide layer 1310 to form a core board opening 3110, and the flexible core board 30 is integrally formed.

[0060] In this embodiment, the flexible circuit board 60 is composed of the characteristics of flexibility, voltage-resistant circuit lines 1120, and grounding circuit lines 1130, forming a flexible circuit board product that supports comprehensive performance.

[0061] The core board opening 3110 corresponds to the area where the conductive adhesive 620 is subsequently screen-printed, providing a channel for the grounding circuit line 1130 to communicate with the conductive adhesive 620 and the reinforcement 610; optionally, the distance between one side of the core board opening 3110 and the grounding circuit line 1130 is less than 20 μm to 125 μm, providing a reliable supporting effect for the grounding circuit line 1130.

[0062] Please continue to refer to Figure 4 , and also refer to Figure 5 and Figure 6 ; Figure 5 is a schematic cross-sectional structure diagram of the laminated board of this embodiment; Figure 6 is Figure 5 a schematic cross-sectional structure diagram of the A-A section of

[0063] Step S30:

[0064] Take the first cover film and the second cover film, stack and laminate the first cover film, the flexible core board 30, and the second cover film in sequence to form a laminated board 50.

[0065] Further, forming the laminated board 50 includes: making a first opening 4130 in the first cover film to form a first opening cover film 410 (including a first cover film polyimide layer 4110 and a first cover film adhesive layer 4120), and the first opening 4130 corresponds to the voltage-resistant circuit line 1120; making a second opening 4230 in the second cover film to form a second opening cover film 420 (including a second cover film polyimide layer 4210 and a second cover film adhesive layer 4220), and the second opening 4230 corresponds to the core board opening 3110; stacking the first opening cover film 410, the flexible core board 30, and the second opening cover film 420 in sequence to form a flexible board stacked structure 40, with the circuit lines 1110 facing the first opening cover film 410, and laminating to form the laminated board 50.

[0066] For the pads or plug lines of the withstand voltage line 1120 that are exposed, the corresponding cover film needs to be made with a first opening 4130, and for the corresponding ground line 1130 where the conductive adhesive 620 needs to be made subsequently, a second opening 4230 needs to be made at the exposed pad position;

[0067] It should be noted that since the line 1110 has been formed, a non - adhesive cover film cannot be used for the cover film anymore, otherwise problems such as lamination offset and fracture of the line 1110 will occur. The first cover film adhesive layer 4120 can provide good bonding force for lamination, and since there is no adhesive layer 1320 between the line 1110 and the polyimide layer 1310, a structure with only one side having the first cover film adhesive layer 4120 is formed after lamination. After testing the finished flexible circuit board 60, its withstand voltage performance has been greatly improved.

[0068] It should be noted that in this embodiment, a second opening cover film 420 is further provided on one side of the adhesive layer 1320. On the one hand (through testing and comparison of the finished product), it can further effectively improve the withstand voltage characteristics, and on the other hand, it can increase the coverage of the board body, thereby improving the reliability.

[0069] Furthermore, the single side of the second opening 4230 is larger than the core board opening 3110. Optionally, it is larger than 50μm to 150μm.

[0070] After lamination, a laminated board 50 is formed. The core board opening 3110 and the second opening 4230 form a stepped opening 510. On the one hand, it can prevent the second opening 4230 from shifting, skewing, expanding or contracting due to errors after lamination and blocking a part of the core board opening 3110. On the other hand, it can provide a better space for accommodating the colloid when screen - printing the conductive adhesive 620 subsequently, preventing problems such as screen - printing holes and trapped air bubbles of the conductive adhesive 620.

[0071] Please refer to Figure 7 ; Figure 7 which is a schematic cross - sectional structure diagram of the flexible circuit board of this embodiment.

[0072] Step S40:

[0073] Attach a reinforcement 610 to the laminated board 50 to form a flexible circuit board 60.

[0074] Furthermore, to form the flexible circuit board 60, it includes: screen - printing the conductive adhesive 620 on one side of the second opening cover film 420 of the laminated board 50, then attaching the reinforcement 610, and laminating to form the flexible circuit board 60.

[0075] Optionally, the conductive adhesive 620 is silver paste epoxy conductive adhesive, copper paste epoxy conductive adhesive, silver paste acrylic conductive adhesive, or copper paste acrylic conductive adhesive; optionally, after the screen printing adhesive layer, pre-baking is performed, generally at a temperature of 65°C to 80°C for 5 min to 20 min to achieve preliminary curing of the colloid.

[0076] Furthermore, the reinforcement 610 is made of a metal material, optionally stainless steel reinforcement, copper sheet reinforcement, or aluminum sheet reinforcement.

[0077] It should be noted that in this embodiment, the reinforcement 610 is designed for the flexible circuit board 60, and the reinforcement 610 is attached to the flexible circuit board 60 through the conductive adhesive 620, especially connected to the ground line 1130 to form an effective grounding network through the reinforcement 610; in fact, generally, flexible circuit boards with plug lines are designed with reinforcements to improve the strength of the plug lines, and the reinforcements are generally made by bonding with an adhesive layer. Therefore, in one embodiment, the flexible circuit board 60 is designed with a plug line, and the reinforcement 610 is provided in the plug line area. In this embodiment, the conductive adhesive 620 is used to replace the traditional insulating glue, achieving the dual functions of both adhering the reinforcement 610 and connecting the line 1110.

[0078] Please refer to Figure 8 ; Figure 8 which is the planar design diagram of the mesh line of this embodiment.

[0079] The ground line 1130 is made into a mesh line 1130A, the line width of the mesh line 1130A is 25 μm to 150 μm, and the adjacent line gap is the line gap of 25 μm to 150 μm.

[0080] After design and testing, if the size of the ground line 1130 is large and the size of the core board opening 3110 is large, since the conductive adhesive 620 contains metal powder particles and the bonding strength is slightly smaller than that of ordinary glue, there may be a problem that the area of the metal copper surface is large after screen printing the conductive adhesive 620, resulting in an insecure bonding force. And because during handling and application, the flexible circuit board 60 will be bent and vibrated, etc., and the reinforcement 610 is prone to generate an interaction force with the flexible circuit board 60, further easily leading to the problem of the reinforcement 610 being insecure. Therefore, the ground line 1130 is made into a mesh line 1130A. In particular, the ground line 1130 within the range of the core board opening 3110 is made into a mesh line 1130A, and the grid space positions expose the adhesive layer 1320, which can form a good bonding effect with the colloid in the conductive adhesive 620, greatly improving the bonding force between the ground line 1130 and the reinforcement 610 through the conductive adhesive 620.

[0081] Please refer to Figure 9 ;Figure 9 It is a schematic diagram of the cross-sectional structure of another pressed plate of this embodiment.

[0082] Furthermore, one side of the reinforcement 610 facing the inner side of the flexible circuit board 60 is a wavy side, that is, the reinforcement 610 is a wavy reinforcement 610A.

[0083] Optionally, the wave shape is a uniform arc-shaped wave line, the height from the vertex to the bottom point of the wave is 0.35mm to 2.0mm, and the length from one vertex to another vertex is 0.35mm to 3.0mm.

[0084] Since the second window covering film 420 is added to improve the voltage resistance characteristics in this embodiment, the overall thickness of the board body is also increased accordingly. When the flexible circuit board 60 is bent in application, the tail end of the reinforcement 610 and the board surface produce mutual friction and scratching forces, which can easily cause the board body of the flexible circuit board 60 to be torn by the tail end of the reinforcement 610. Therefore, a wavy reinforcement 610A is used to reduce the resistance of the reinforcement 610 to the bending of the flexible circuit board 60 and enhance the buffering effect.

[0085] See also Figure 10 , Figure 11 and Figure 12 ; Figure 10 This is a plan view of the corrugated reinforcement of this embodiment; Figure 11 for Figure 5 Schematic diagram of BB cross-section structure; Figure 12 It is a schematic diagram of the cross-sectional structure of another flexible circuit board according to this embodiment.

[0086] In one embodiment, the second cover film covers the region of the withstand voltage line 1120 .

[0087] After the attachment, a local covering film 420A is formed to form another type of pressed board 50A; after the attachment of the reinforcement 610, another type of flexible circuit board 60A is formed.

[0088] When the board size is large and the distribution spacing of the circuits 1110 is large, in order to further reduce the hindrance of the second covering film to the overall bending performance, the covering film can be selectively attached only to the area of ​​the voltage-resistant circuit 1120 to form a processing method of locally attaching the covering film, and can effectively reduce the window openings on the surface of the conductive adhesive 620 corresponding to the grounding circuit 1130 (that is, there are only core board windows 3110, and no second windows 4230), which is more convenient for silk screen printing of the conductive adhesive 620; and for the adhesive layer 1320 not covered by the covering film, those located in the reinforcement 610 area can be covered by the conductive adhesive 620, and those located in other areas can be aged by high-temperature baking. Optionally, baking at 100°C to 150°C for 20min to 60min.

[0089] It should be noted that due to the high precision of the circuit board in the actual design and manufacturing process, the actual structure diagram and the dimensions such as the thickness between each layer and the line width are all at the micron level. For example, the thickness of each layer is generally between 5μm and 50μm. If the accompanying drawings of the specification are made according to the actual scale, there will be a problem of unclear illustration. Therefore, in order to more clearly show the implementation process of the manufacturing method, the accompanying drawings of this embodiment are all schematic diagrams with the technical features enlarged, which do not represent the dimensions of the actual structure diagram, nor do they represent an enlarged diagram of the actual structure diagram in proportion.

[0090] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and the accompanying drawings of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle, characterized in that: The manufacturing method includes the following steps: S10: Take a copper foil and a single-sided flexible copper clad laminate with a laminated structure of a polyimide layer, an adhesive layer, and a copper layer in sequence. Attach a high-temperature resistant blue adhesive to one side of the copper foil to form a blue adhesive copper foil. Perform plasma activation treatment on the single-sided flexible copper clad laminate, and then perform chemical activation treatment to form an activated copper clad laminate. Stack the blue adhesive copper foil and the activated copper clad laminate, with the copper foil facing the polyimide layer, and press them together to form a flexible pressed board; S20: Peel off the high-temperature resistant blue adhesive, make circuits on the copper foil of the flexible pressed board, and remove the copper layer to form a flexible core board; S30: Take a first cover film and a second cover film, stack the first cover film, the flexible core board, and the second cover film in sequence, and press them together to form a pressed board; S40: Stick a reinforcement on the pressed board to form the flexible circuit board.

2. The manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle according to claim 1, characterized in that, Forming the flexible pressed board includes: Stack the copper foil and the activated copper clad laminate to form a stacked structure; sequentially arrange a release film, a covering film, a release film, an aluminum sheet, and a release film from near to far on both sides of the stacked structure to form a layout structure, and press them together to form the flexible pressed board.

3. The manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle according to claim 1 or 2, characterized in that, Forming the flexible core board includes: The circuit making includes making a withstand voltage circuit and making a grounding circuit; after removing the copper layer, open windows on the adhesive layer and the polyimide layer to form core board windows, and integrally form the flexible core board.

4. The manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle according to claim 3, characterized in that, Forming the pressed board includes: Make a first window on the first cover film to form a first window cover film, and the first window corresponds to the withstand voltage circuit; make a second window on the second cover film to form a second window cover film, and the second window corresponds to the core board window; stack the first window cover film, the flexible core board, and the second window cover film in sequence, with the circuits facing the first window cover film, and press them together to form the pressed board.

5. The manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle according to claim 4, characterized in that, The single side of the second window is larger than the core board window.

6. The manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle according to claim 4 or 5, characterized in that, Forming the flexible circuit board includes: Screen-print conductive adhesive on one side of the second window cover film of the pressed board, then stick the reinforcement, and press them together to form the flexible circuit board.

7. The manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle according to claim 6, characterized in that, The reinforcement is a metal material reinforcement.

8. The manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle according to claim 4, characterized in that, The second cover film covers the area of the withstand voltage circuit.

9. The manufacturing method of a voltage-resistant flexible circuit board for a new energy vehicle according to claim 1, characterized in that One side of the reinforcement facing the interior direction of the flexible circuit board body is a wavy edge.

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