Flexible circuit board manufacturing method
Through the flexible circuit board production method of cutting first and then combining, the problem of waste of metal materials in the prior art is solved, and efficient utilization of metal materials is achieved and continuous production is ensured.
Patent Information
- Application Number
- CN202411552133.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-02-11
AI Technical Summary
It is difficult to avoid waste of metal materials during the production of existing flexible circuit boards, resulting in high production costs.
By cutting first and then combining, the metal foil is cut into multiple metal strips arranged side by side through the first die-cutting roller, and the metal strips are separated by the guide roller and the matching member, so that the spacing is greater than zero, thereby forming the first The conductive layer is pressed on the insulating film to fix its position.
On the premise of ensuring continuous production, the waste of metal materials is effectively avoided, the utilization rate of metal materials is improved, and the conductive layer meets design requirements.
Smart Images
Figure CN119421334A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of flexible circuit boards, and specifically relates to a method for manufacturing a flexible circuit board. Background Art
[0002] Flexible circuit boards are referred to as "soft boards" and are commonly known as FPCs in the industry. They are printed circuit boards made of flexible insulating substrates and have many advantages that rigid printed circuit boards do not have. For example, they can be bent, curved, and folded freely. The use of flexible circuit boards can greatly reduce the size of electronic products and meet the needs of electronic products developing in the direction of high density, miniaturization, and high reliability. Therefore, flexible circuit boards have been widely used in aerospace, military, mobile communications, laptops, computer peripherals, PDAs, digital cameras, and other fields or products.
[0003] Existing flexible circuit boards generally include single-layer boards and double-layer boards. A single-layer board is a flexible circuit board with one conductive layer, including a first insulating layer, a conductive layer, and a second insulating layer stacked in sequence. A double-layer board is a flexible circuit board with two conductive layers, including a first insulating layer, a first conductive layer, a second insulating layer, a second conductive layer, and a third insulating layer stacked in sequence.
[0004] Whether it is a single-layer board or a double-layer board, the conductive layer can be cut from the metal layer according to the designed circuit pattern, wherein the circuit structure in the conductive layer of the single-layer board and the second conductive layer of the double-layer board is usually designed as a number of circulation units arranged along the length direction of the flexible circuit board, and these circulation units will realize the series and parallel connection of components, while the circuit structure in the first conductive layer of the double-layer board is usually designed as a number of metal strips arranged along the width direction of the flexible circuit board and extending infinitely along the length direction of the flexible circuit board, and these metal strips will serve as the positive and negative poles of the power supply to the components connected to the second conductive layer. Two adjacent metal strips are set apart, and after the metal layer is cut to form the second conductive layer, long strips of waste will be generated between the two adjacent metal strips, resulting in waste of metal materials and high production costs. Summary of the invention
[0005] The present invention aims to overcome at least one defect in the prior art and provide a method for manufacturing a flexible circuit board, which solves the problem of inevitable waste of metal materials in the manufacturing process while ensuring continuous production.
[0006] In order to solve the above technical problems, the present invention proposes a method for manufacturing a flexible circuit board, wherein the flexible circuit board comprises a first insulating layer and a first conductive layer, both of which have a length direction and a width direction, and the first conductive layer comprises at least two metal strips arranged in parallel along the width direction, and the spacing between two adjacent metal strips is greater than zero. In particular, the manufacturing method comprises the following steps:
[0007] S1. Cutting the metal foil into a plurality of groups of metal strips arranged in parallel along the width direction by a first die-cutting roller, each group of metal strips comprising two or more metal strips arranged in parallel along the width direction, and the distance between two adjacent metal strips is zero;
[0008] S2. Separating the plurality of metal strips obtained in step S1 by a guide roller so that the distance between two adjacent metal strips is greater than zero, thereby forming a first conductive layer, and supporting the metal strips by a matching member located between the first die-cutting roller and the guide roller so that the length of each metal strip between the first die-cutting roller and the guide roller is kept consistent;
[0009] S3. The first conductive layer obtained in step S2 is pressed onto the first insulating film by a first embossing roller to form a first insulating layer on one side of the first conductive layer.
[0010] This solution abandons the existing mode of closing first and cutting later, and creatively proposes a solution of cutting first and closing later. In the process of cutting, multiple closely arranged metal strips are formed, and no metal foil waste is generated between two adjacent metal strips, which greatly improves the utilization rate of metal materials. Between cutting and closing, the closely arranged multiple metal strips are separated by the cooperation of the guide roller and the matching part, ensuring that the metal strips are arranged in strict accordance with the design requirements. In the process of closing, the relative position relationship of the multiple metal strips arranged according to the design requirements is fixed in time through the first insulating film, ensuring that the first conductive layer meets the design requirements and the continuity of production.
[0011] Multiple metal strips are tangent to the first die-cutting roller to form a first tangent, tangent to the matching piece to form a second tangent, and tangent to the guide roller to form a third tangent; the first tangent and the third tangent are both straight lines, the second tangent is an axisymmetric curve, the first tangent and the third tangent are parallel to the plane where the second tangent is located, and perpendicular to the symmetry axis of the second tangent. A plane rectangular coordinate system with the symmetry axis of the second tangent as the Y axis is established on the plane where the second tangent is located, and any point (x, y) on the second tangent satisfies the following formula, which is conducive to ensuring that each metal strip is in a taut state between the first die-cutting roller and the guide roller.
[0012]
[0013] Among them, h0 represents the ordinate of the midpoint of the second tangent, h1 represents the ordinate of the projection of the first tangent on the plane where the second tangent is located, h2 represents the ordinate of the projection of the third tangent on the plane where the second tangent is located, d1 represents the distance between the first tangent and the plane where the second tangent is located, d2 represents the distance between the third tangent and the plane where the second tangent is located, W represents the sum of the target widths of all metal strips in the group, A represents the sum of the target spacings of all metal strips in the group, and B represents the target spacing between two adjacent metal strips between groups.
[0014] If the target width and target spacing of all metal strips are the same, any point (x, y) on the second tangent line satisfies the following formula to ensure that each metal strip is in a taut state between the first die-cutting roller and the guide roller.
[0015]
[0016] Among them, h0 represents the ordinate of the midpoint of the second tangent, h1 represents the ordinate of the projection of the first tangent on the plane where the second tangent is located, h2 represents the ordinate of the projection of the third tangent on the plane where the second tangent is located, d1 represents the distance between the first tangent and the plane where the second tangent is located, d2 represents the distance between the third tangent and the plane where the second tangent is located, w represents the target width of each metal strip, and a represents the target spacing between two adjacent metal strips.
[0017] The matching piece is preferably a toothless plate or a comb-toothed plate. The side of the toothless plate facing the metal strip is set as a smooth curved surface, and multiple metal strips are tangent to the curved surface to form a second tangent line. The side of the comb-toothed plate facing the metal strip is a toothed curved surface, and multiple metal strips are tangent to the curved surface to form a second tangent line. If the metal foil is a copper foil, the matching piece is preferably a comb-toothed plate; if the metal foil is a copper-aluminum composite foil, the matching piece is preferably a toothless plate.
[0018] The roller surface of the guide roller is provided with multiple groups of grooves arranged in parallel along the axial direction, each group of grooves includes at least two grooves arranged in parallel along the axial direction, each groove surrounds the roller surface, closes end to end to form a ring, and the plane in which it is located is perpendicular to the axis of the guide roller, the number of grooves is equal to the number of metal strips, and the width and spacing of the grooves match the target width and target spacing of the corresponding metal strips, so that multiple metal strips that are closely adjacent to each other can be separated from each other and arranged at a distance.
[0019] In the above manufacturing method, step S1 preferably includes: collecting waste generated after the metal foil is cut by a first waste roller. Thus, the first conductive layer can be made of a metal foil with a width slightly larger than the sum of the widths of all metal strips, so as to reduce the precision requirements for processing equipment and the difficulty of purchasing raw materials.
[0020] In the above manufacturing method, step S3 preferably includes: pressing the first conductive layer and the first insulating film again by a second embossing roller, so as to improve the stability of the bonding between the first conductive layer and the first insulating film.
[0021] In the above-mentioned manufacturing method, step S3 preferably includes: cutting the edge of the first insulating film by a second die-cutting roller, and collecting the waste generated after the first insulating film is cut by a second waste roller. Thus, the first insulating layer can be made of a first insulating film with a width slightly larger than the target width of the first insulating layer, so as to reduce the difficulty of purchasing raw materials.
[0022] The above-mentioned manufacturing method preferably includes the following steps to manufacture the second insulating layer, the second conductive layer and the third insulating layer sequentially arranged in the flexible circuit board:
[0023] S4. Cutting the metal layer attached to the second insulating film by a third die-cutting roller, peeling and collecting the waste generated after the metal layer is cut by a third waste roller, cutting the second insulating film and the metal layer by a fourth die-cutting roller, peeling and collecting the waste generated after the second insulating film and the metal layer are cut by a fourth waste roller, to form a second insulating layer and a second conductive layer;
[0024] S5. Cutting the component holes of the third insulating film by a fifth die-cutting roller, and stripping and collecting the waste generated after the third insulating film is cut by a fifth waste roller to form a third insulating layer;
[0025] S6. The first insulating layer, the first conductive layer, the second insulating layer, the second conductive layer and the third insulating layer stacked in sequence are pressed together by a third embossing roller.
[0026] The first die-cutting roller, the second die-cutting roller, the third die-cutting roller, the fourth die-cutting roller and / or the fifth die-cutting roller respectively include a knife roller and a smooth roller that cooperate with each other; the roller surface of the knife roller is provided with a cutting edge for cutting metal foil, metal layer and / or insulating film; the roller surface of the smooth roller is set as a smooth surface for carrying the cut metal foil, metal layer and / or insulating film; the two cooperate with each other to achieve the cutting of the metal foil, metal layer and / or insulating film.
[0027] The roller surface of the first die-cutting roller and / or the second die-cutting roller is dynamically wrapped with a knife film, and the roller surface of the fourth die-cutting roller and / or the fifth die-cutting roller is dynamically wrapped with a waste discharge film, which is beneficial to prevent the knife edge of the knife roller from damaging the roller surface of the smooth roller, thereby protecting the smooth roller. At the same time, the knife edge depth of the knife roller can be designed to be slightly larger than the thickness of the cut metal foil, metal layer and / or insulating film to ensure that the cut metal foil, metal layer and / or insulating film can be completely cut. In addition, the viscosity of the waste discharge film can also peel off the waste from the cut metal layer and / or insulating film to achieve the purpose of waste discharge.
[0028] Compared with the prior art, this solution has the following beneficial effects: it abandons the existing mode of closing first and cutting later, and creatively proposes a solution of cutting first and closing later, so that a plurality of closely arranged metal strips are formed in the process of cutting, and no metal foil waste is generated between two adjacent metal strips, which greatly improves the utilization rate of metal materials; between cutting and closing, the closely arranged plurality of metal strips are separated by the cooperation of the guide roller and the matching part, ensuring that the metal strips are arranged at a distance strictly in accordance with the design requirements; in the process of closing, the relative position relationship of the plurality of metal strips arranged in accordance with the design requirements is fixed in time through the first insulating film, ensuring that the first conductive layer meets the design requirements and the continuity of production. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The drawings are for illustrative purposes only and should not be construed as limitations on the present invention. In order to better illustrate the present invention, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.
[0030] Figure 1 It is a structural diagram of a flexible circuit board.
[0031] Figure 2 It is a flow chart of a method for manufacturing a flexible circuit board (first conductive layer).
[0032] Figure 3 It is an operation diagram of a method for manufacturing a first conductive layer of a flexible circuit board.
[0033] Figure 4 It is a structural schematic diagram of the guide roller.
[0034] Figure 5 It is a top view schematic diagram of the manufacturing process of the first conductive layer of the flexible circuit board.
[0035] Figure 6 It is a structural schematic diagram of a toothless plate.
[0036] Figure 7 It is a structural schematic diagram of the comb plate.
[0037] Figure 8 It is a flow chart of a method for manufacturing a flexible circuit board (including a second conductive layer).
[0038] Explanation of the reference numerals: first insulating film 001, metal foil 002, knife pad film 003, waste discharge film 004, first insulating layer 010, first conductive layer 020, metal strip 021, second insulating layer 030, connecting hole 032, second conductive layer 040, circulation unit 041, connecting hole 042, third insulating layer 050, component hole 052, first die-cutting roller 110, first knife roller 111, first optical roller 112, first guide roller 113, second die-cutting roller 120, second knife roller 121, second optical roller 122, second guide roller 123, guide roller 210, matching piece 220, toothless plate 221, comb plate 222, first embossing roller 310, first steel roller 311, first rubber roller 312, second embossing roller 320, second steel roller 321, second rubber roller 322, first waste roller 410, second waste roller 420. DETAILED DESCRIPTION
[0039] In order to enable those skilled in the art to better understand the present solution, the present solution is further described in detail below in conjunction with specific embodiments.
[0040] Figure 1 A possible flexible circuit board is illustrated. The flexible circuit board includes an insulating layer and a conductive layer, wherein the insulating layer includes a first insulating layer 010, a second insulating layer 030 and a third insulating layer 050, and the conductive layer includes a first conductive layer 020 and a second conductive layer 040. The first insulating layer 010, the second insulating layer 030 and the third insulating layer 050 are sequentially arranged, the first conductive layer 020 is arranged between the first insulating layer 010 and the second insulating layer 030, and the second conductive layer 040 is arranged between the second insulating layer 030 and the third insulating layer 050, thereby achieving separation and coating of the first conductive layer 020 and the second conductive layer 040, forming a structure in which the first insulating layer 010, the first conductive layer 020, the second insulating layer 030, the second conductive layer 040 and the third insulating layer 050 are sequentially stacked.
[0041] The flexible circuit board and its insulating layer and conductive layer all have a length direction and a width direction. They can be infinitely extended in the length direction and can also be rolled up around an axis parallel to the width direction. The third insulating layer 050 is provided with a component hole 052, so that components such as lamp beads and resistors can be electrically connected to the second conductive layer 040 through the third insulating layer 050; the second conductive layer 040 includes a plurality of circulation units 041 arranged along the length direction, and these circulation units 041 can realize the series connection of components; the second conductive layer 040 and the second insulating layer 030 are provided with connecting holes 042032 running through the two, so that the second conductive layer 040 can be electrically connected to the first conductive layer 020 through solder or the like; the first conductive layer 020 includes at least two metal strips 021 arranged in parallel along the width direction, and these metal strips 021 are respectively connected to the positive and negative poles of the power supply, so that the parallel connection between components can be realized. The number of metal strips 021 is usually determined by the design requirements of the flexible circuit board. For example, the first conductive layer 020 of a single-color flexible circuit board is usually designed with two metal strips 021, the first conductive layer 020 of a two-color flexible circuit board is usually designed with three metal strips 021, and the first conductive layer 020 of a three-color flexible circuit board is usually designed with four metal strips 021. At least one of these metal strips 021 is connected to the positive pole of the power supply, and at least one is connected to the negative pole of the power supply; if the first conductive layer 020 is provided with two metal strips 021, one of them is connected to the positive pole of the power supply, and the other is connected to the negative pole of the power supply; if the first conductive layer 020 is provided with three or more metal strips 021, one of them may be connected to one pole of the power supply, and the remaining metal strips 021 are connected to the other pole of the power supply.
[0042] The insulating layer can be an insulating film made of an insulating material, specifically, a double-sided non-adhesive insulating film, or a single-sided or double-sided adhesive insulating film. The conductive layer is usually made of metal materials such as copper, copper-aluminum alloy, etc. The metal material can be directly deposited on the insulating film, or it can be made into a metal foil and then bonded to the insulating film. The metal foil can be bonded to the double-sided non-adhesive insulating film by an adhesive, etc., or it can be bonded to the single-sided or double-sided adhesive insulating film by hot pressing. In order to achieve continuous production, the insulating layer is preferably a single-sided or double-sided adhesive insulating film, wherein the first insulating layer 010 and the third insulating layer 050 are single-sided adhesive insulating films, and the second insulating layer 030 is double-sided adhesive insulating films. The conductive layer is bonded to the adhesive surface of the insulating film by hot pressing.
[0043] In the existing conductive layer manufacturing process, a whole metal layer is usually formed on the insulating film by deposition, lamination, etc., and then the metal layer is etched, die-cut, etc. according to the designed circuit pattern to remove excess metal material to ensure that the remaining circulation units 041 or metal strips 021 after processing are arranged according to the designed circuit, but the process of removing excess metal material also causes waste of metal material. The existing method of manufacturing the conductive layer can be called the first-bonding-then-cutting method.
[0044] Figures 2-3 The process flow chart and operation diagram of the new flexible circuit board manufacturing method are shown. The manufacturing method is used to manufacture at least the first conductive layer of the above-mentioned flexible circuit board, which can be called the first-cut-then method. Compared with the existing first-assemble-then-cut method, it can greatly save the material cost of metal materials. Figures 2-3 As shown, the manufacturing method may include the following steps.
[0045] Step S1, cutting the metal foil into a plurality of groups of metal strips arranged in parallel along the width direction by a first die-cutting roller, each group of metal strips includes two or more metal strips arranged in parallel along the width direction, and the distance between two adjacent metal strips is zero.
[0046] The first conductive layer 020 is made of an independent metal foil 002 , and the metal foil 002 may be a copper foil or a copper-aluminum composite foil, wherein the copper foil may be a rolled copper foil or an electrolytic copper foil.
[0047] The number of metal strips 021 in a single flexible circuit board is determined by the design requirements, usually 2 to 4 strips, and the overall width is small. It is not conducive to ensuring production efficiency and processing accuracy to process the flexible circuit board one by one. Therefore, in the process of processing the flexible circuit board, multiple flexible circuit boards are usually combined and processed into a full-page flexible circuit board, and then the strips are die-cut to form a single flexible circuit board. To this end, in this step, the metal foil 002 is cut into multiple groups of metal strips 021 arranged in parallel along the width direction. One group of metal strips 021 corresponds to a single flexible circuit board. Each group of metal strips 021 includes more than two metal strips 021 arranged in parallel along the width direction. The number of metal strips 021 in the group is determined by the design requirements of the single flexible circuit board, and finally multiple metal strips 021 arranged in parallel along the width direction are formed. The spacing between two adjacent metal strips 021 is zero, which means that the multiple metal strips 021 cut out are close to each other, avoiding the generation of excess metal foil 002 waste between the two adjacent metal strips 021 cut out, and greatly improving the utilization rate of the metal foil 002.
[0048] The metal foil 002 is cut by the first die-cutting roller 110 to achieve continuous production. The first die-cutting roller 110 and the second die-cutting roller 120, the third die-cutting roller, the fourth die-cutting roller and the fifth die-cutting roller hereinafter may be collectively referred to as die-cutting rollers. The die-cutting rollers generally include a knife roller and a smooth roller. The roller surface of the knife roller is provided with a knife edge, and the roller surface of the smooth roller is provided with a smooth surface. The two cooperate with each other to achieve cutting of the metal foil 002, the insulating film, etc. The die-cutting roller may also include a guide roller. The front and rear sides of the knife roller and the smooth roller may each be provided with a guide roller so that the cut metal foil 002, the insulating film, etc. are close to the roller surface of the smooth roller.
[0049] The knife roller of the first die-cutting roller 110 can be called the first knife roller 111, the smooth roller can be called the first smooth roller 112, and the guide roller can be called the first guide roller 113. The roller surface of the first knife roller 111 is provided with a plurality of annular knife edges arranged in parallel along the axial direction and surrounding the roller surface, and the plane where each knife edge is located is perpendicular to the axis of the first knife roller 111, so as to ensure that the metal strip 021 formed by cutting is a rectangle with infinite length, and the spacing between two adjacent knife edges is adapted to the target width of the corresponding metal strip 021, so that the multiple metal strips 021 cut out are close to each other (the spacing is zero). The roller surface of the first smooth roller 112 can be dynamically wrapped with a pad knife film 003, which is conducive to preventing the knife edge of the first knife roller 111 from damaging the roller surface of the first smooth roller 112, so as to achieve the purpose of protecting the first smooth roller 112. At the same time, the knife edge depth of the first knife roller 111 can be designed to be slightly larger than the thickness of the metal foil 002, so as to ensure that the metal foil 002 can be completely cut.
[0050] Theoretically, all metal strips 021 with a target width of M can be processed and manufactured using metal foil 002 with the same width of M, which can completely avoid material waste. However, this requires extremely high cutting accuracy, and it is necessary to ensure that the metal foil 002 is completely aligned with the first die-cutting roller 110 when passing through the first die-cutting roller 110. Moreover, the metal foil 002 is often purchased from upstream suppliers. Unless customized, it is difficult to directly purchase the metal foil 002 with a width consistent with the sum of the target widths of all metal strips 021. In order to reduce the accuracy requirements for processing equipment and the difficulty of purchasing raw materials, all metal strips 021 with a target width of M can be processed and manufactured using metal foil 002 with a width slightly larger than M. When the metal foil 002 is cut to form a plurality of metal strips 021, excess waste is generated on both sides of these metal strips 021. These wastes are continuous and can be wound and collected by the first waste roller 410.
[0051] Step S2, separating the multiple metal strips obtained in step S1 by means of guide rollers so that the distance between two adjacent metal strips is greater than zero, thereby forming a first conductive layer. At the same time, the metal strips are supported by a matching piece located between the first die-cutting roller and the guide roller so that the length of each metal strip between the first die-cutting roller and the guide roller remains consistent.
[0052] The metal strips 021 are connected to the positive and negative electrodes of the power supply so as to supply power to components such as lamp beads electrically connected to the flexible circuit board. To avoid short circuit, a certain distance must be left between two adjacent metal strips 021, and the size of the distance is determined by the design requirements of the flexible circuit board. To reduce or even avoid the waste of metal foil 002, the metal strips 021 coming out of the first die-cutting roller 110 are close to each other in pairs. In this step, these metal strips 021 are separated in pairs (the distance is greater than zero), so that they are arranged in a distance along the width direction to form a first conductive layer 020 that meets the design requirements.
[0053] Multiple metal strips 021 that are closely connected to each other can be separated from each other and arranged at a distance by the guide roller 210. Figure 4 As shown, the roller surface of the guide roller 210 is provided with a plurality of groups of grooves arranged in parallel along the axial direction, each group of grooves includes at least two grooves arranged in parallel along the axial direction, each groove surrounds the roller surface, closes end to end into a ring, and the plane in which it is located is perpendicular to the axis of the guide roller 210. The number of grooves is equal to the number of metal strips 021. Specifically, the number of groups and strips of grooves are respectively consistent with the number of groups and strips of metal strips 021 obtained in step S1, so each metal strip 021 has a corresponding groove on the guide roller 210, and the groove carries and guides the direction of the corresponding metal strip 021. The width and spacing of the grooves match the target width and target spacing of the corresponding metal strip 021, so all metal strips 021 are separated by a certain distance in pairs under the guidance of the corresponding grooves, and are arranged at a distance in the width direction according to the design requirements to form the first conductive layer 020.
[0054] like Figure 5 As shown, at the moment of coming out of the first die-cutting roller 110, the width of all the metal strips 021 is equal to the sum of their widths, and at the moment of coming out of the guide roller 210, the width of all the metal strips 021 is equal to the sum of their widths plus the sum of their spacings, forming an isosceles trapezoid between the first die-cutting roller 110 and the guide roller 210. Since the lengths of all the metal strips 021 coming out of the first die-cutting roller 110 are substantially the same, when the metal strips 021 at the edge of the isosceles trapezoid are in a taut state, the metal strips 021 in the middle of the isosceles trapezoid are still in a loose state, which is not conducive to ensuring that the metal strips 021 in the first conductive layer 020 formed finally are arranged strictly according to the design requirements. In order to make all the metal strips 021 in a taut state between the first die-cutting roller 110 and the guide roller 210, in this step, a matching piece 220 is used between the first die-cutting roller 110 and the guide roller 210 to support the metal strips 021 so that the length of each metal strip 021 between the first die-cutting roller 110 and the guide roller 210 remains consistent.
[0055] The plurality of metal strips 021 are tangent to the first die-cutting roller 110 to form a first tangent line l1, tangent to the matching piece 220 to form a second tangent line l2, and tangent to the guide roller 210 to form a third tangent line l3. The first tangent line l1 and the third tangent line l3 are both straight lines, and the second tangent line l2 is an axisymmetric curve. The first tangent line l1 and the third tangent line l3 are parallel to the plane where the second tangent line l2 is located, and are perpendicular to the symmetry axis of the second tangent line l2. A plane rectangular coordinate system with the symmetry axis of the second tangent line as the Y axis is established on the plane where the second tangent line is located. Any point (x, y) on the second tangent line satisfies the following formula, which is conducive to ensuring that each metal strip 021 is in a taut state between the first die-cutting roller 110 and the guide roller 210.
[0056]
[0057] Among them, h0 represents the ordinate of the midpoint of the second tangent, h1 represents the ordinate of the projection of the first tangent on the plane where the second tangent is located, h2 represents the ordinate of the projection of the third tangent on the plane where the second tangent is located, d1 represents the distance between the first tangent and the plane where the second tangent is located, d2 represents the distance between the third tangent and the plane where the second tangent is located, W represents the sum of the target widths of all metal strips 021 in the group, A represents the sum of the target spacings of all metal strips 021 in the group, and B represents the target spacing between two adjacent metal strips 021 between groups.
[0058] If the target widths and target spacings of all metal strips 021 are the same, any point (x, y) on the second tangent line that satisfies the following equation can ensure that each metal strip 021 is in a taut state between the first die-cutting roller 110 and the guide roller 210 .
[0059]
[0060] Among them, h0 represents the ordinate of the midpoint of the second tangent, h1 represents the ordinate of the projection of the first tangent on the plane where the second tangent is located, h2 represents the ordinate of the projection of the third tangent on the plane where the second tangent is located, d1 represents the distance between the first tangent and the plane where the second tangent is located, d2 represents the distance between the third tangent and the plane where the second tangent is located, w represents the target width of each metal strip 021, and a represents the target spacing between two adjacent metal strips 021.
[0061] The matching member 220 can be a plate or a rotating member, and the former is preferred. The plate can be a toothless plate 221 or a comb plate 222. Figure 6 As shown, the side of the toothless plate 221 facing the metal strip 021 is set as a smooth curved surface, and a plurality of metal strips 021 are tangent to the curved surface to form the above-mentioned second tangent line. Figure 7 As shown, the side of the comb plate 222 facing the metal strip 021 is a toothed curved surface, and a plurality of metal strips 021 are tangent to the curved surface to form a second tangent line. The teeth of the comb plate 222 can guide the metal strip 021, but the metal strip 021 of some materials is easily scratched by the teeth when passing through the comb plate 222. Therefore, the manufacturer can select a suitable matching piece 220 according to the material of the metal foil 002 used in the first conductive layer 020. If the metal foil 002 is a copper foil, the matching piece 220 is preferably a comb plate 222; if the metal foil 002 is a copper-aluminum composite foil, the matching piece 220 is preferably a toothless plate 221.
[0062] Step S3, laminating the first conductive layer obtained in step S2 onto the first insulating film by a first embossing roller to form a first insulating layer on one side of the first conductive layer.
[0063] After the guide roller 210 guides all the metal strips 021 to be arranged at a distance according to the design requirements, the relative position relationship of all the metal strips 021 needs to be fixed in time to ensure that the first conductive layer 020 meets the design requirements. In this step, the first conductive layer 020 obtained in step S2 is laminated on the first insulating film 001, so that the relative position relationship of all the metal strips 021 is fixed, and at the same time, the first insulating film 001 forms a first insulating layer on one side of the first conductive layer 020.
[0064] The first conductive layer 020 and the first insulating film 001 are hot-pressed (referred to as pressed) by the first embossing roller 310 to achieve continuous production. The first embossing roller 310 and the second embossing roller 320, the third embossing roller, the fourth embossing roller and the fifth embossing roller described below can be collectively referred to as embossing rollers, and the embossing rollers include steel rollers and rubber rollers, both of which are heating elements. The steel roller of the first embossing roller 310 can be referred to as the first steel roller 311, and the first steel roller 311 can increase the squeezing force of the embossing roller on the first conductive layer 020 and the first insulating film 001, and the rubber roller of the first embossing roller 310 can be referred to as the first rubber roller 312, and the first rubber roller 312 can increase the contact area between the embossing roller and the first conductive layer 020 and the first insulating film 001, and the two cooperate with each other to ensure that the first conductive layer 020 and the first insulating film 001 are firmly attached.
[0065] In order to improve the stability of the first conductive layer 020 and the first insulating film 001, the first conductive layer 020 and the first insulating film 001 can be pressed again by the second embossing roller 320. The steel roller of the second embossing roller 320 can be called the second steel roller 321, and the second steel roller 321 can increase the squeezing force of the embossing roller on the first conductive layer 020 and the first insulating film 001. The rubber roller of the second embossing roller 320 can be called the second rubber roller 322, and the second rubber roller 322 can increase the contact area between the embossing roller and the first conductive layer 020 and the first insulating film 001. The two cooperate with each other to ensure that the first conductive layer 020 and the first insulating film 001 are firmly attached.
[0066] Theoretically, the first insulating layer with a target width of K can be processed and manufactured using the first insulating film 001 with the same width of K, which can completely avoid material waste. However, the first insulating film 001 is often purchased directly from outside. Unless customized, it is difficult to directly purchase the first insulating film 001 with a width consistent with the target width of the first insulating layer. In order to reduce the difficulty of purchasing raw materials, the first insulating layer with a target width of K can be processed and manufactured using the first insulating film 001 with a width slightly larger than K. During the processing, the first insulating film 001 can be edge-cut by the second die-cutting roller 120. After the first insulating film 001 is cut, excess waste is generated on both sides. These wastes are continuous and can be wound and collected by the second waste roller 420. The second die-cutting roller 120 can edge-cut the first insulating film 001 after the first lamination, and can also edge-cut the first insulating film 001 after the second lamination.
[0067] The knife roller of the second die-cutting roller 120 can be referred to as the second knife roller 121, the smooth roller thereof can be referred to as the second smooth roller 122, and the guide roller thereof can be referred to as the second guide roller 123. The roller surface of the second knife roller 121 is provided with two annular knife edges arranged in parallel along the axial direction and surrounding the roller surface, and the plane where each knife edge is located is perpendicular to the axis of the second knife roller 121, so as to ensure that the second insulating layer formed by cutting is a rectangle of infinite length, and the spacing between two adjacent knife edges is adapted to the target width of the second insulating layer, so that the width of the cut second insulating layer is consistent with the target width. The roller surface of the second smooth roller 122 can be dynamically wound with a pad knife film 003, which is helpful to avoid the knife edge of the second knife roller 121 from damaging the roller surface of the second smooth roller 122, so as to achieve the purpose of protecting the second smooth roller 122. At the same time, the knife edge depth of the second knife roller 121 can be designed to be slightly larger than the thickness of the second insulating film, so as to ensure that the second insulating film can be completely cut.
[0068] The above-mentioned manufacturing method abandons the existing mode of first closing and then cutting, and creatively proposes a scheme of first cutting and then closing. In the process of cutting, a plurality of metal strips 021 arranged closely are formed, and no metal foil 002 waste is generated between two adjacent metal strips 021, which greatly improves the utilization rate of metal materials. Between cutting and closing, the plurality of metal strips 021 arranged closely are separated by the cooperation of the guide roller 210 and the matching member 220, ensuring that the metal strips 021 are arranged at a distance strictly in accordance with the design requirements. In the process of closing, the relative position relationship of the plurality of metal strips 021 arranged in accordance with the design requirements is fixed in time through the first insulating film 001, ensuring that the first conductive layer 020 meets the design requirements and the continuity of production.
[0069] In addition to the above steps, the production method may also include the following steps: Figure 8 As shown, the second insulating layer, the second conductive layer and the third insulating layer are used to make the above-mentioned flexible circuit board.
[0070] Step S4, using the third die-cutting roller to cut the circuit of the metal layer attached to the second insulating film, and using the third waste roller to peel off and collect the waste generated after the metal layer is cut, and using the fourth die-cutting roller to cut the connecting holes between the second insulating film and the metal layer, and using the fourth waste roller to peel off and collect the waste generated after the second insulating film and the metal layer are cut, so as to form a second insulating layer and a second conductive layer.
[0071] The knife roller of the third die-cutting roller can be called the third knife roller, and the smooth roller can be called the third smooth roller. The roller surface of the third knife roller is provided with a knife edge corresponding to the line shape of the second conductive layer to ensure that the line shape formed by cutting is consistent with the target shape. During the cutting process, the second insulating film that is not cut is next to the third smooth roller, not the cut metal layer. It is not necessary to dynamically wind a knife film around the roller surface of the third smooth roller to avoid the knife edge of the third knife roller from damaging the roller surface of the third smooth roller, and the knife edge depth of the third knife roller can be designed to be slightly larger than the thickness of the metal layer to ensure that the metal layer can be completely cut off. The waste generated after the metal layer is cut is continuous and can be collected by winding it through the third waste roller.
[0072] The knife roller of the fourth die-cutting roller can be called the fourth knife roller, and the smooth roller thereof can be called the fourth smooth roller. The roller surface of the fourth knife roller is provided with a knife edge corresponding to the connecting hole, ensuring that the shape and position of the connecting hole formed by cutting on the second insulating film and the metal layer are consistent with the target. The waste generated after the second insulating film and the metal layer are cut is discontinuous, and a waste discharge film can be dynamically wound on the roller surface of the fourth smooth roller, and the waste can be peeled off from the second insulating film and the metal layer by the viscosity of the waste discharge film, and the waste discharge film can be collected by winding through the fourth waste roller. At the same time, the waste discharge film can also act as a knife pad film to prevent the knife edge of the fourth knife roller from damaging the roller surface of the fourth smooth roller, thereby achieving the purpose of protecting the fourth smooth roller, and the knife edge depth of the fourth knife roller can be designed to be slightly larger than the sum of the thickness of the second insulating film and the metal layer, so as to ensure that the second insulating film and the metal layer can be completely cut off.
[0073] Step S5, cutting component holes in the third insulating film by a fifth die-cutting roller, and at the same time peeling and collecting waste generated after the third insulating film is cut by a fifth waste roller, so as to form a third insulating layer.
[0074] The knife roller of the fifth die-cutting roller can be called the fifth knife roller, and the smooth roller thereof can be called the fifth smooth roller. The roller surface of the fifth knife roller is provided with a knife edge corresponding to the component hole, ensuring that the shape and position of the component hole formed by cutting on the third insulating film are consistent with the target. The waste generated after the third insulating film is cut is discontinuous, and a waste discharge film can be dynamically wound on the roller surface of the fifth smooth roller, and the waste can be peeled off from the third insulating film by the viscosity of the waste discharge film, and the waste discharge film can be collected by winding through the fifth waste roller. At the same time, the waste discharge film can also act as a knife pad film to prevent the knife edge of the fifth knife roller from damaging the roller surface of the fifth smooth roller, thereby achieving the purpose of protecting the fifth smooth roller, and the knife edge depth of the fifth knife roller can be designed to be slightly larger than the thickness of the third insulating film to ensure that the third insulating film can be completely cut off.
[0075] Step S6, pressing the first insulating layer, the first conductive layer, the second insulating layer, the second conductive layer and the third insulating layer stacked in sequence together by a third embossing roller.
[0076] The steel roller of the third embossing roller can be called the third steel roller, and the third steel roller can increase the squeezing force of the third embossing roller on the first insulating layer, the first conductive layer, the second insulating layer, the second conductive layer and the third insulating layer. The rubber roller of the third embossing roller can be called the third rubber roller, and the third rubber roller can increase the contact area between the third embossing roller and the first insulating layer, the first conductive layer, the second insulating layer, the second conductive layer and the third insulating layer. The two cooperate with each other to ensure that the first insulating layer, the first conductive layer, the second insulating layer, the second conductive layer and the third insulating layer are firmly fitted.
[0077] Before laminating the first insulating layer, the first conductive layer, the second insulating layer, the second conductive layer and the third insulating layer, the first insulating layer and the first conductive layer which have been combined into one can be firstly laminarized with the second insulating layer and the second conductive layer which have been combined into one by the fourth embossing roller, and then the first insulating layer, the first conductive layer, the second insulating layer, the second conductive layer and the third insulating layer which have been combined into one can be laminarized with the third embossing roller; or the second insulating layer and the second conductive layer which have been combined into one can be firstly laminarized with the fifth embossing roller, and then the first insulating layer and the first conductive layer which have been combined into one can be laminarized with the second insulating layer, the second conductive layer and the third insulating layer which have been combined into one by the third embossing roller.
[0078] The steel roller of the fourth embossing roller can be called the fourth steel roller, and the fourth steel roller can increase the extrusion force of the fourth embossing roller on the first insulating layer, the first conductive layer, the second insulating layer and the second conductive layer. The rubber roller of the fourth embossing roller can be called the fourth rubber roller, and the fourth rubber roller can increase the contact area between the fourth embossing roller and the first insulating layer, the first conductive layer, the second insulating layer and the second conductive layer. The two cooperate with each other to ensure that the first insulating layer, the first conductive layer, the second insulating layer and the second conductive layer are firmly fitted.
[0079] The steel roller of the fifth embossing roller can be called the fifth steel roller, and the fifth steel roller can increase the extrusion force of the fifth embossing roller on the second insulating layer, the second conductive layer and the third insulating layer. The rubber roller of the fifth embossing roller can be called the fifth rubber roller, and the fifth rubber roller can increase the contact area between the fifth embossing roller and the second insulating layer, the second conductive layer and the third insulating layer. The two cooperate with each other to ensure that the second insulating layer, the second conductive layer and the third insulating layer are firmly fitted.
[0080] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.
Claims
1. A method for manufacturing a flexible circuit board, wherein the flexible circuit board comprises a first insulating layer and a first conductive layer, both of which have a length direction and a width direction, the first conductive layer comprises at least two metal strips arranged in parallel along the width direction, and the spacing between two adjacent metal strips is greater than zero; characterized in that: The production method comprises the following steps: S1. Cutting the metal foil into a plurality of groups of metal strips arranged in parallel along the width direction by a first die-cutting roller, each group of metal strips comprising two or more metal strips arranged in parallel along the width direction, and the spacing between two adjacent metal strips is zero; S2. Separating the plurality of metal strips obtained in step S1 by a guide roller so that the distance between two adjacent metal strips is greater than zero, thereby forming a first conductive layer. Meanwhile, the metal strips are supported by a matching member between the first die-cutting roller and the guide roller so that the length of each metal strip between the first die-cutting roller and the guide roller is kept consistent; S3. The first conductive layer obtained in step S2 is pressed onto the first insulating film by a first embossing roller to form a first insulating layer on one side of the first conductive layer.
2. The method for manufacturing a flexible circuit board according to claim 1, characterized in that: The plurality of metal strips are tangent to the first die-cutting roller to form a first tangent, tangent to the matching piece to form a second tangent, and tangent to the guide roller to form a third tangent; the first tangent and the third tangent are both straight lines, the second tangent is an axisymmetric curve, the first tangent and the third tangent are parallel to the plane where the second tangent is located, and perpendicular to the symmetry axis of the second tangent; a plane rectangular coordinate system with the symmetry axis of the second tangent as the Y axis is established on the plane where the second tangent is located, then any point (x, y) on the second tangent satisfies: Among them, h0 represents the ordinate of the midpoint of the second tangent, h1 represents the ordinate of the projection of the first tangent on the plane where the second tangent is located, h2 represents the ordinate of the projection of the third tangent on the plane where the second tangent is located, d1 represents the distance between the first tangent and the plane where the second tangent is located, d2 represents the distance between the third tangent and the plane where the second tangent is located, W represents the sum of the target widths of all metal strips in the group, A represents the sum of the target spacings of all metal strips in the group, and B represents the target spacing between two adjacent metal strips between groups.
3. The method for manufacturing a flexible circuit board according to claim 2, characterized in that: If all metal bars have the same target width and target spacing, then any point (x, y) on the second tangent line satisfies: Among them, h0 represents the ordinate of the midpoint of the second tangent, h1 represents the ordinate of the projection of the first tangent on the plane where the second tangent is located, h2 represents the ordinate of the projection of the third tangent on the plane where the second tangent is located, d1 represents the distance between the first tangent and the plane where the second tangent is located, d2 represents the distance between the third tangent and the plane where the second tangent is located, w represents the target width of each metal strip, and a represents the target spacing between two adjacent metal strips.
4. The method for manufacturing a flexible circuit board according to claim 2 or 3, characterized in that: The matching piece is a toothless plate or a comb-toothed plate; the side of the toothless plate facing the metal strip is set as a smooth curved surface, and multiple metal strips are tangent to the curved surface to form the second tangent line; the side of the comb-toothed plate facing the metal strip is a toothed curved surface, and multiple metal strips are tangent to the curved surface to form the second tangent line.
5. The method for manufacturing a flexible circuit board according to claim 4, characterized in that: If the metal foil is a copper foil, the matching piece is a comb-tooth plate; if the metal foil is a copper-aluminum composite foil, the matching piece is a toothless plate.
6. The method for manufacturing a flexible circuit board according to any one of claims 1 to 3, characterized in that: The roller surface of the guide roller is provided with a plurality of groups of grooves arranged in parallel along the axial direction, each group of grooves includes at least two grooves arranged in parallel along the axial direction, each groove surrounds the roller surface, is closed end to end to form a ring, and the plane in which it is located is perpendicular to the axis of the guide roller, the number of grooves is equal to the number of metal strips, and the width and spacing of the grooves match the target width and target spacing of the corresponding metal strips.
7. The method for manufacturing a flexible circuit board according to any one of claims 1 to 3, characterized in that: The step S1 of the manufacturing method further includes: collecting waste generated after the metal foil is cut by a first waste roller.
8. The method for manufacturing a flexible circuit board according to any one of claims 1 to 3, characterized in that: Step S3 of the production method further comprises: The first conductive layer and the first insulating film are pressed together again by a second embossing roller; and / or, The edge of the first insulating film is cut by the second die-cutting roller, and the waste generated after the first insulating film is cut is collected by the second waste roller.
9. The method for manufacturing a flexible circuit board according to claim 8, characterized in that: The flexible circuit board further comprises a second insulating layer, a second conductive layer and a third insulating layer which are arranged in sequence, and the manufacturing method further comprises the following steps: S4. Cutting the metal layer attached to the second insulating film by a third die-cutting roller, peeling and collecting the waste generated after the metal layer is cut by a third waste roller, cutting the second insulating film and the metal layer by a fourth die-cutting roller, peeling and collecting the waste generated after the second insulating film and the metal layer are cut by a fourth waste roller, to form a second insulating layer and a second conductive layer; S5. Cutting the component holes of the third insulating film by a fifth die-cutting roller, and stripping and collecting the waste generated after the third insulating film is cut by a fifth waste roller to form a third insulating layer; S6. The first insulating layer, the first conductive layer, the second insulating layer, the second conductive layer and the third insulating layer stacked in sequence are pressed together by a third embossing roller.
10. The method for manufacturing a flexible circuit board according to claim 9, characterized in that: The first die-cutting roller, the second die-cutting roller, the third die-cutting roller, the fourth die-cutting roller and / or the fifth die-cutting roller respectively include a knife roller and a smooth roller that cooperate with each other, the roller surface of the knife roller is provided with a knife edge, and the roller surface of the smooth roller is set as a smooth surface; the roller surface of the smooth roller of the first die-cutting roller and / or the second die-cutting roller is dynamically wrapped with a knife pad film, and the roller surface of the smooth roller of the fourth die-cutting roller and / or the fifth die-cutting roller is dynamically wrapped with a waste discharge film.