Manufacturing method of voltage-resistant flexible circuit board for new energy automobile

Abstract

The invention discloses a manufacturing method of a voltage-resistant flexible circuit board for a new energy automobile, and the method comprises the steps: taking a copper foil, taking a single-sided flexible copper-clad plate with a structure of sequentially laminating a PI layer, an adhesive layer and a copper layer, stacking and laminating the copper foil and the single-sided flexible copper-clad plate to form a flexible laminated plate, manufacturing a circuit for the copper foil of the flexible laminated plate, and removing the copper layer, thereby obtaining the voltage-resistant flexible circuit board for the new energy automobile. Forming a flexible core board, taking a first covering film and a second covering film, sequentially stacking and laminating the first covering film, the flexible core board and the second covering film to form a laminated board, and reinforcing the laminated board to form the flexible circuit board; the adhesive-layer-free single-sided copper-clad plate is manufactured and formed through a transfer method, the adhesive-layer-free single-sided copper-clad plate has higher voltage resistance, a grounding circuit is designed to be connected with a reinforcement through a conductive adhesive, a grounding circuit network is achieved, and the mode that the reliability is low and the applicability is poor when the grounding circuit is connected with a grounding module through a welding mode is avoided; the whole process manufacturing method is formed, and the method has good synergy.

Description

Technical Field

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

[0002] With the continuous development of new energy vehicles, their intelligence, multi-function and networking performance are constantly improving. Some control units are required to have higher voltage resistance and grounding performance. Due to the miniaturization of control unit modules, internal circuit boards are required to be flexibly distributed in a smaller space. Therefore, flexible circuit boards with single-layer copper lines are used to replace traditional connecting harnesses to achieve flexible installation and better voltage resistance and grounding performance.

[0003] Currently, this type of flexible circuit board is made using a traditional manufacturing method, that is, a single-sided flexible copper-clad laminate with a thicker copper thickness is used to make a core board to form a voltage-resistant circuit and a grounding circuit, which is then stacked and pressed with other layers, and processed through a post-processing step to form a flexible circuit board; a thicker copper layer circuit is used to achieve a higher voltage-resistant performance, and the grounding circuit is used to be subsequently welded to the grounding component of the electronic module to form a good grounding property.

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

[0005] Based on the above background and problems, it is necessary to provide a new manufacturing method for improving the voltage resistance and grounding performance of a flexible circuit board. Summary of the invention

[0006] The present invention aims at the problem that a flexible circuit board with a withstand voltage circuit and a grounding circuit has insufficient withstand voltage performance and a complicated grounding design and grounding process. A method for manufacturing a withstand voltage flexible circuit board for new energy vehicles is provided. The manufacturing method comprises the following steps: S10: taking a copper foil and a single-sided flexible copper-clad laminate having a laminate structure of a polyimide layer, an adhesive layer, and a copper layer in sequence, stacking the copper foil and the single-sided flexible copper-clad laminate, and pressing them together to form a flexible pressed laminate; S20: making a circuit on the copper foil of the flexible laminate, and removing the copper layer to form a flexible core board; S30: taking a first covering film and a second covering film, stacking the first covering film, the flexible core board and the second covering film in sequence, and pressing them together to form a pressed board; S40: reinforcing the laminated plate to form the flexible circuit board.

[0007] Furthermore, forming the flexible laminated board includes: attaching high temperature resistant blue glue to one side of the copper foil to form blue glue copper foil; subjecting the single-sided flexible copper clad laminate to plasma activation treatment, and then 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 laminating them to form the flexible laminated board.

[0008] Furthermore, forming the flexible laminate includes: stacking the copper foil and the activated copper clad laminate to form a stacked structure; sequentially arranging a release film, a coating film, a release film, an aluminum sheet, and a release film on both sides of the stacked structure from near to far to form a layout structure, and laminating them to form the flexible laminate.

[0009] Furthermore, the flexible core board is formed, including: the circuit manufacturing includes manufacturing a voltage-resistant circuit and a grounding circuit; after removing the copper layer, opening windows in the adhesive layer and the polyimide layer to form core board windows, thereby forming the flexible core board as a whole.

[0010] Furthermore, forming the laminated board includes: making a first window on the first covering film to form a first window covering film, the first window corresponding to the voltage-resistant circuit; making a second window on the second covering film to form a second window covering film, the second window corresponding to the core board window; stacking the first window covering film, the flexible core board and the second window covering film in sequence, with the circuit facing the first window covering film, and laminating them to form the laminated board.

[0011] Furthermore, a single side of the second window is larger than the core panel window.

[0012] Furthermore, forming the flexible circuit board includes: screen printing conductive glue on one side of the second window cover film of the press plate, then attaching the reinforcement, and pressing to form the flexible circuit board.

[0013] Furthermore, the reinforcement is made of metal material.

[0014] Furthermore, the second covering film covers a region of the withstand voltage circuit.

[0015] Furthermore, one side of the reinforcement facing the inner side of the flexible circuit board body is a wavy side.

[0016] The technical solution of the present invention first performs plasma activation and then chemical activation on the single-sided copper clad laminate, and uses a high-temperature resistant blue glue for copper foil attachment and transfer to achieve interlayer transfer through a pressing method to produce a single-sided copper clad laminate without an adhesive layer, thereby providing a copper clad laminate foundation with higher voltage resistance performance, and adding a second window covering film to further improve the voltage resistance performance and increase the coverage performance of the flexible circuit board; and by designing a grounding line, a conductive glue is used to connect the reinforcing connection to realize the process of the grounding line network, thereby avoiding the process of connecting the board pad grounding line to the grounding module by welding, thereby improving the machinability and applicability of the grounding line, and the production process adopts a design The combination of core board windowing and second windowing realizes a good interconnection between the conductive glue and the grounding line, which effectively improves product reliability. The overall process forms the production of glue-free copper clad laminate, and then introduces the second windowing covering film to increase the covering performance and voltage resistance performance. However, since the grounding line is designed to be interconnected with the reinforcement through conductive glue, the second windowing covering film affects the production process of the conductive glue and the reinforcement. Therefore, the core board windowing and the second windowing are designed to provide good windowing conditions for the production of conductive glue, and the network line is further designed to improve the bonding performance of the grounding line through conductive glue and the reinforcement, thereby realizing the synergy and correlation of the overall processing process and forming a good process-based production method. 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 The main process flow chart of the embodiment of the present invention is included; Figure 2 is a schematic cross-sectional structure diagram of the typesetting structure of this embodiment; Figure 3 is a schematic diagram of the cross-sectional structure of the flexible pressed plate of this embodiment; Figure 4 is a schematic cross-sectional structure diagram of a flexible board stacking structure of this embodiment; Figure 5 is a schematic diagram of the cross-sectional structure of the pressed plate of this embodiment; Figure 6 for Figure 5 AA cross-sectional structure schematic diagram; Figure 7 is a schematic diagram of the cross-sectional structure of the flexible circuit board of this embodiment; Figure 8 is a plan view of the mesh circuit of this embodiment; Fig. 9 is a schematic diagram of the cross-sectional structure of another pressed plate of this embodiment; Fig.10 This is a plan view of the corrugated reinforcement of this embodiment; Fig.11 for Fig.10 Schematic diagram of BB cross-section structure; Fig.12 It is a schematic diagram of the cross-sectional structure of another flexible circuit board according to this embodiment.

[0019] Explanation of the accompanying symbols: 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, glue 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 coating film; 1520, second coating film; 1610, first aluminum sheet; 1620, second aluminum sheet; 1710, upper table of press; 1720, lower table of press; 20, flexible laminate; 30, flexible core board; 1110, circuit; 1120 , voltage-resistant circuit; 1130, grounding circuit; 1140, ordinary circuit; 3110, core board window; 40, flexible board stacking structure; 410, first window covering film; 4110, first covering film polyimide layer; 4120, first covering film adhesive layer; 4130, first window; 420, second window covering film; 4210, second covering film polyimide layer; 4220, second covering film adhesive layer; 4230, second window; 50, pressing plate; 510, stepped window; 60, flexible circuit board; 610, reinforcement; 620, conductive adhesive; 50A, another pressing plate; 420A, partial covering film; 60A, another flexible circuit board; 1130A, mesh circuit; 610A, wavy reinforcement.

[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 The main process flow chart included in the embodiment of the present invention.

[0026] A method for manufacturing a voltage-resistant flexible circuit board for new energy vehicles according to an embodiment of the present invention comprises: Figure 1 The main production process is described in detail step by step as follows.

[0027] See also Figure 2 and Figure 3 ; Figure 2 is a schematic cross-sectional structure diagram of the typesetting structure of this embodiment; Figure 3 It is a schematic diagram of the cross-sectional structure of the flexible pressed plate of this embodiment.

[0028] Step S10: Take the 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 , stack the copper foil 110 and the single-sided flexible copper-clad laminate, and press them together to form a flexible laminated board 20 .

[0029] Furthermore, a flexible laminate 20 is formed, including: attaching a high temperature resistant blue glue 120 to one side of the copper foil 110 to form a blue glue copper foil 1020; subjecting a single-sided flexible copper clad laminate to plasma activation treatment, and then chemical activation treatment to form an activated copper clad laminate 130; stacking the blue glue copper foil 1020 and the activated copper clad laminate 130, with the copper foil 110 facing the polyimide layer 1310, and pressing them together to form a flexible laminate 20.

[0030] Optionally, the copper foil 110 has a thickness of 35 μm to 245 μm; a thicker thickness can carry a greater voltage.

[0031] Optionally, the high temperature resistant temperature of the high temperature resistant blue glue 120 is 160° C. to 220° C.; the high temperature resistant blue glue 120 is an auxiliary transfer film used in the process, which can withstand the high temperature and high pressure lamination process of the subsequent process and can be peeled off smoothly.

[0032] Optionally, the blue-glue copper foil 1020 is micro-etched or super-roughened so that the copper foil 110 can form a good bonding process and bonding force with the polyimide layer 1310 during the subsequent lamination process, thereby avoiding problems such as false lamination, delamination, and voids.

[0033] Optionally, the plasma activation treatment is to use a plasma device and parameters in the prior art to perform appropriate treatment so as to introduce hydroxyl groups (—OH) into the surface of the polyimide layer 1310 to improve the hydrophilicity of the surface.

[0034] Optionally, the chemical activation treatment is performed using the activation section of the copper plating processing line of the prior art, which can further improve the activation effect and uniform surface roughness of the polyimide layer 1310 after plasma activation, and improve the surface hydrophilicity and activity.

[0035] The reason why the method of first plasma activation treatment and then chemical activation treatment is adopted is that the production method of this embodiment is to first produce a glue-free copper-clad laminate consisting of only a polyimide layer 1310 and a copper foil 110 without a glue layer 1320, but the polyimide layer 1310 is highly inert and generally difficult to combine 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 between the copper foil 110, thereby forming a glue-free substrate, and realizing a glue-free copper-clad laminate with good bonding force of interlayer peeling force > 15N.

[0036] Further, the flexible laminate 20 is formed, including: stacking the copper foil 110 and the activated copper clad laminate 130 to form a stacked structure 10A; and sequentially placing release films (including adhesive Figure 2The first release film 1410 and the fourth release film 1440), the coating film (respectively including the attached Figure 2 The first laminating film 1510 and the second laminating film 1520), the release film (respectively including the attached Figure 2 The second release film 1420 and the fifth release film 1450 in the aluminum sheet (respectively including the attached Figure 2 The first aluminum sheet 1610 and the second aluminum sheet 1620 in the embodiment of the present invention), the release film (respectively including the attached Figure 2 The third release film 1430 and the sixth release film 1460 are formed into a layout structure 10, which is placed between the upper table 1710 and the lower table 1720 of the press and pressed to form a flexible pressing plate 20.

[0037] The release film can provide good release properties after lamination, and can be made of polyimide material or polytetrafluoroethylene material; the coating film can provide effective buffering and thermal conductivity during the lamination process, and can be made of silicone pad, kraft paper and other materials; the aluminum sheet has good leveling and thermal conductivity.

[0038] This embodiment combines the existing single-sided flexible copper clad laminate with a single-layer copper foil 110 by pressing, and forms a single-sided flexible copper clad laminate without an adhesive layer 1320 through a film transfer processing method, thereby effectively improving the overall glass transition temperature, thermochemical properties, and tensile strength of the copper clad laminate, reducing the expansion and contraction ratio, improving the comprehensive performance of the material, and effectively avoiding the influence of the adhesive layer of the single-sided copper clad laminate in the prior art on the voltage resistance performance of the flexible circuit board 60.

[0039] It is worth noting that, in this embodiment, the maximum pressure for laminating the blue glue copper foil 1020 and the activated copper clad laminate 130 is relatively large, which can be optionally 18kg / cm² to 30kg / cm²; the pressing temperature is relatively high, which can be optionally 160℃ to 220℃; the pressing time under the condition of maximum pressure is relatively long, which can be optionally 15min to 40min; ensuring the formation of a good glue-free copper clad laminate material.

[0040] See also Figure 4 ; Figure 4 Schematic diagram of the cross-sectional structure of the flexible board stacking structure of this embodiment.

[0041] Step S20: The high temperature resistant blue glue 120 is used to make a circuit 1110 on the copper foil 110 of the flexible laminated board 20 , and the copper layer 1330 is removed to form a flexible core board 30 .

[0042] Furthermore, a flexible core board 30 is formed, including: making a circuit 1110 including making a voltage-resistant circuit 1120 and making a grounding circuit 1130, and also including a common circuit 1140; after removing the copper layer 1330, opening windows in the glue layer 1320 and the polyimide layer 1310 to form a core board window 3110, and forming a flexible core board 30 as a whole.

[0043] In this embodiment, the flexible circuit board 60 is composed of the characteristics of flexibility, the voltage-resistant circuit 1120, and the grounding circuit 1130, forming a flexible circuit board product supporting comprehensive performance.

[0044] The core board window 3110 corresponds to the area of ​​the subsequent silk-screened conductive adhesive 620, providing a channel for the grounding circuit 1130 to connect with the conductive adhesive 620 and the reinforcement 610; optionally, the single side of the core board window 3110 is smaller than the grounding circuit 1130 by 20μm to 125μm, providing reliable support for the grounding circuit 1130.

[0045] Please continue reading Figure 4 , and see Figure 5 and Figure 6 ; Figure 5 is a schematic diagram of the cross-sectional structure of the pressed plate of this embodiment; Figure 6 for Figure 5 Schematic diagram of the AA cross-section structure.

[0046] Step S30: Take the first covering film and the second covering film, stack the first covering film, the flexible core board 30 and the second covering film in sequence, and press them together to form a pressed board 50 .

[0047] Furthermore, a laminated board 50 is formed, including: making a first window 4130 on the first covering film to form a first window covering film 410 (including a first covering film polyimide layer 4110 and a first covering film adhesive layer 4120), the first window 4130 corresponds to the voltage-resistant circuit 1120; making a second window 4230 on the second covering film to form a second window covering film 420 (including a second covering film polyimide layer 4210 and a second covering film adhesive layer 4220), the second window 4230 corresponds to the core board window 3110; stacking the first window covering film 410, the flexible core board 30 and the second window covering film 420 in sequence to form a flexible board stacking structure 40, with the circuit 1110 facing the first window covering film 410, and laminating to form a laminated board 50.

[0048] The exposed pad or plug circuit of the withstand voltage circuit 1120 needs to have a first opening 4130 made in the corresponding cover film, and the corresponding grounding circuit 1130 of the conductive adhesive 620 needs to be made later, and the exposed pad position needs to have a second opening 4230 made; It is worth noting that since the circuit 1110 has been formed, the covering film cannot use a non-glue covering film, otherwise it will cause problems such as circuit 1110 lamination displacement and breakage. The first covering film glue layer 4120 can provide good bonding force for lamination, and since there is no glue layer 1320 between the circuit 1110 and the polyimide layer 1310, a structure with only one side having the first covering film glue layer 4120 is formed after lamination. After testing the finished flexible circuit board 60, its voltage resistance performance is greatly improved.

[0049] It is worth noting that the present embodiment further provides a second window covering film 420 on one side of the adhesive layer 1320 , which can further effectively improve the withstand voltage characteristics (after testing and comparing the finished product) and increase the coverage of the board, thereby improving reliability.

[0050] Furthermore, a single side of the second window 4230 is larger than the core window 3110, and optionally, is larger than 50 μm to 150 μm.

[0051] After lamination, a lamination plate 50 is formed, and the core board window 3110 and the second window 4230 form a stepped window 510. On the one hand, it can prevent the second window 4230 from offset, skewing, expanding or shrinking due to errors after lamination, thereby blocking a part of the core board window 3110. On the other hand, it can provide a better space for accommodating the conductive adhesive 620 during subsequent screen printing, thereby preventing the conductive adhesive 620 from having problems such as screen printing voids and bubbles.

[0052] See also Figure 7 ; Figure 7 Schematic diagram of the cross-sectional structure of the flexible circuit board of this embodiment.

[0053] Step S40: A reinforcement 610 is attached to the laminated plate 50 to form a flexible circuit board 60 .

[0054] Furthermore, forming the flexible circuit board 60 includes: screen printing the conductive adhesive 620 on one side of the second window cover film 420 of the pressing plate 50 , and then attaching the reinforcement 610 , and pressing to form the flexible circuit board 60 .

[0055] Optionally, the conductive adhesive 620 is silver paste epoxy resin conductive adhesive, copper paste epoxy resin conductive adhesive, silver paste acrylic conductive adhesive, copper paste acrylic conductive adhesive; optionally, the screen printing adhesive layer is pre-baked, generally at a temperature of 65°C to 80°C, for 5 to 20 minutes, to achieve initial curing of the colloid.

[0056] Furthermore, the reinforcement 610 is a metal reinforcement, which can be stainless steel reinforcement, copper sheet reinforcement or aluminum sheet reinforcement.

[0057] It is worth noting that, in this embodiment, a reinforcement 610 is designed for the flexible circuit board 60, and the reinforcement 610 is attached and combined with the flexible circuit board 60 through a conductive glue 620, and is particularly connected to the grounding line 1130, so as to form an effective network grounded through the reinforcement 610; in fact, in general, 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 adhesive layers. Therefore, in one embodiment, the flexible circuit board 60 is designed with a plug line, and a reinforcement 610 is provided in the plug line area. In this embodiment, a conductive glue 620 is used instead of traditional insulating glue, so as to achieve the dual functions of adhering the reinforcement 610 and achieving the connection of the line 1110.

[0058] See also Figure 8 ; Figure 8 This is a plan view of the mesh circuit of this embodiment.

[0059] 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 gap between adjacent lines is a line gap of 25 μm to 150 μm.

[0060] After design and testing, if the grounding circuit 1130 is large in size and the core board window 3110 is large in size, the conductive glue 620 contains metal powder particles, which has a slightly smaller bonding strength than ordinary glue. Therefore, after screen printing the conductive glue 620, the area of ​​the metal copper surface may be large, resulting in a problem of weak bonding. In addition, during transportation and application, the flexible circuit board 60 may bend, vibrate, etc., and the reinforcement 610 is prone to generate interaction force with the flexible circuit board 60, which is further prone to cause the reinforcement 610 to be weak. Therefore, the grounding circuit 1130 is made into a mesh circuit 1130A. In particular, the grounding circuit 1130 within the core board window 3110 is made into a mesh circuit 1130A, and the glue layer 1320 is exposed at the space position of the grid, which can form a good bonding effect with the colloid in the conductive glue 620, greatly improving the bonding force between the grounding circuit 1130 and the reinforcement 610 through the conductive glue 620.

[0061] See also Fig. 9 ; Fig. 9 It is a schematic diagram of the cross-sectional structure of another pressed plate of this embodiment.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] See also Fig.10 , Fig.11 and Fig.12 ; Fig.10 This is a plan view of the corrugated reinforcement of this embodiment; Fig.11 for Figure 5 Schematic diagram of BB cross-section structure; Fig.12 It is a schematic diagram of the cross-sectional structure of another flexible circuit board according to this embodiment.

[0066] In one embodiment, the second cover film covers the region of the withstand voltage line 1120 .

[0067] 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.

[0068] 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.

[0069] It is worth noting that due to the actual design and processing of circuit boards, the actual structure diagram and the thickness of each layer, line width and other dimensions are all in the micron level. For example, the thickness of each layer is generally 5μm to 50μm. If the drawings in the specification are made according to the actual proportion, there will be a problem of unclear drawings. Therefore, in order to more clearly show the implementation process of the manufacturing method, the drawings of this embodiment are all schematic diagrams that enlarge the technical features, which do not represent the size of the actual structure diagram, nor do they represent enlarged views of the actual structure diagram in proportion.

[0070] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, 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 voltage-resistant flexible circuit board for new energy vehicles, characterized in that: The production method comprises the following steps: S10: taking a copper foil and a single-sided flexible copper-clad laminate having a laminate structure of a polyimide layer, an adhesive layer, and a copper layer in sequence, stacking the copper foil and the single-sided flexible copper-clad laminate, and pressing them together to form a flexible pressed laminate; S20: making a circuit on the copper foil of the flexible laminate, and removing the copper layer to form a flexible core board; S30: taking a first covering film and a second covering film, stacking the first covering film, the flexible core board and the second covering film in sequence, and pressing them together to form a pressed board; S40: reinforcing the laminated plate to form the flexible circuit board.

2. The method for manufacturing a voltage-resistant flexible circuit board for new energy vehicles according to claim 1, characterized in that: The flexible laminate is formed, including: attaching high temperature resistant blue glue to one side of the copper foil to form blue glue copper foil; subjecting the single-sided flexible copper clad laminate to plasma activation treatment, and then 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 together to form the flexible laminate.

3. The method for manufacturing a voltage-resistant flexible circuit board for new energy vehicles according to claim 2, characterized in that: The flexible laminate is formed by stacking the copper foil and the activated copper-clad laminate to form a stacked structure; a release film, a coating film, a release film, an aluminum sheet, and a release film are sequentially arranged on both sides of the stacked structure from near to far to form a layout structure, and the structures are pressed together to form the flexible laminate.

4. A method for manufacturing a voltage-resistant flexible circuit board for new energy vehicles according to claim 1, 2 or 3, characterized in that: The flexible core board is formed by: making the circuit including making a voltage-resistant circuit and making a grounding circuit; after removing the copper layer, opening windows in the glue layer and the polyimide layer to form core board windows, thereby forming the flexible core board as a whole.

5. The method for manufacturing a voltage-resistant flexible circuit board for new energy vehicles according to claim 4, characterized in that: The forming of the laminated board includes: making a first window on the first covering film to form a first window covering film, the first window corresponding to the voltage-resistant circuit; making a second window on the second covering film to form a second window covering film, the second window corresponding to the core board window; stacking the first window covering film, the flexible core board and the second window covering film in sequence, with the circuit facing the first window covering film, and laminating them to form the laminated board.

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

7. The method for manufacturing a voltage-resistant flexible circuit board for new energy vehicles according to claim 5 or 6, characterized in that: The flexible circuit board is formed, comprising: Conductive adhesive is screen-printed on one side of the second window cover film of the laminated plate, and then the reinforcement is attached and laminated to form the flexible circuit board.

8. The method for manufacturing a voltage-resistant flexible circuit board for new energy vehicles according to claim 7, characterized in that: The reinforcement is made of metal.

9. The method for manufacturing a voltage-resistant flexible circuit board for new energy vehicles according to claim 1 or 5, characterized in that: The second cover film covers a region of the withstand voltage circuit.

10. The method for manufacturing a voltage-resistant flexible circuit board for new energy vehicles according to claim 1, characterized in that: The side of the reinforcement facing the inner side of the flexible circuit board body is a wavy side.

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