High-frequency and high-speed multilayer bending-resistant FPC and manufacturing method thereof
By setting support filler inside the first PTFE layer of the core plate instead of the second PTFE layer of the daughter plate, the problems of increased FPC thickness and poor bending effect are solved, and high-frequency high-speed signal transmission and good bending are achieved Folding performance multi-layer FPC.
Patent Information
- Application Number
- CN202411434817.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2025-02-18
AI Technical Summary
When existing FPCs use PTFE material as dielectric layer, the increase in thickness and the addition of fillers lead to the inability to achieve bending effect, which affects normal use.
Support filler is provided inside the first PTFE layer of the core plate, and support filler is not provided inside the second PTFE layer of the two daughter plates. High-frequency and high-speed multi-layer bending-resistant FPC is formed through the lamination arrangement and pressing process.
The small thickness and good bending performance of the FPC are achieved, ensuring the normal use of the FPC, and improving the problem of the board caused by excessive warping and deformation.
Smart Images
Figure CN119485916A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of printed circuit board manufacturing, and in particular to a high-frequency, high-speed, multi-layer, bending-resistant FPC and a manufacturing method thereof. Background Art
[0002] In the design process of FPC (Flexible Printed Circuit) for high-frequency and high-speed signal transmission, we must not only consider how to achieve higher signal transmission efficiency and minimize the loss during signal transmission, but also make it meet the requirements of assembly and bending. Currently, there are two main structures of FPC:
[0003] The first method is to use MPI (Modified Polyimide) or LCP (Liquid Crystal Polymer) as the dielectric layer. Compared with the traditional PI (Polyimide) medium, these two dielectric layers have the characteristics of low loss and bending resistance, but the loss will increase during signal transmission. Although it can meet the bending requirements to a certain extent, it cannot meet some FPCs with lower signal loss requirements.
[0004] The second method is to use PTFE (Polytetrafluoroethylene) with a thickness of more than 3 mil as the dielectric layer, which can effectively reduce the energy loss during signal transmission and improve the efficiency of signal transmission. Due to the unique softness of PTFE, in order to increase its manufacturability, some supporting fillers such as ceramic powder and glass fiber cloth are generally added to PTFE, which will increase the thickness of the dielectric layer, resulting in the thickness of the FPC being more than 0.5mm. The increase in the thickness of the FPC board and the addition of fillers will cause it to be unable to achieve the bending effect, affecting normal use. Summary of the invention
[0005] The present application provides a high-frequency, high-speed, multi-layer, bending-resistant FPC and a method for manufacturing the same, which can improve the problem in the related art that when PTFE material is used as a dielectric layer, the increase in FPC thickness and the addition of fillers result in the inability to achieve the bending effect, affecting normal use.
[0006] In a first aspect, an embodiment of the present application provides a high-frequency, high-speed, multi-layer, bending-resistant FPC, including a unit board, wherein the unit board includes:
[0007] A core plate, the core plate comprising a first PTFE layer and two first metal layers, the two first metal layers are respectively arranged on two opposite sides of the first PTFE layer, and a supporting filler is arranged inside the first PTFE layer;
[0008] Two connection layers, one of the connection layers is connected to one of the first metal layers, and the other connection layer is connected to the other first metal layer;
[0009] Two sub-plates, one of which is connected to one of the connecting layers, and the other of which is connected to the other of the connecting layers, wherein the sub-plates include a second PTFE layer and a second metal layer, wherein the second metal layer is located on a side of the second PTFE layer away from the core plate.
[0010] In some embodiments, the supporting filler includes silica fiber or glass fiber.
[0011] In some embodiments, the supporting filler includes first fiber strips and second fiber strips that are interwoven vertically and horizontally, and an extending direction of the first fiber strips is neither parallel nor perpendicular to a long side direction of the core board.
[0012] In some embodiments, the angle between the extension direction of the first fiber strip and the long side direction of the core plate is 45°, 50° or 60°.
[0013] In some of the embodiments, the two sub-plates are symmetrically arranged with the supporting filler as the center.
[0014] In some of the embodiments, in the arrangement direction of the two first metal layers, the supporting filler separates the first PTFE layer into two parts with the same thickness.
[0015] In a second aspect, the embodiment of the present application provides a method for manufacturing a high-frequency, high-speed, multi-layer, bending-resistant FPC as described in the first aspect, comprising:
[0016] The core board, the two connection layers and the two sub-boards are stacked and pressed together.
[0017] In some embodiments, before stacking and pressing the core board, the two connection layers and the two sub-boards together, the method for manufacturing the high-frequency, high-speed, multi-layer, bending-resistant FPC further includes:
[0018] Providing a panel, the panel comprising a waste part and a plurality of the unit boards, the panel having a molding line, the unit boards and the waste part being separated by the molding line, the waste part comprising a process edge located at an edge of the panel and / or a panel edge located between two adjacent unit boards, the process edge being provided with a reinforcing metal layer in the same layer as the first metal layer and / or the second metal layer;
[0019] The panel is divided into a plurality of unit panels along the forming line.
[0020] In some embodiments, the distance between the reinforcing metal layer and the forming line is greater than or equal to 5 mm.
[0021] In some embodiments, before stacking and pressing the core board, the two connection layers and the two sub-boards together, the method for manufacturing the high-frequency, high-speed, multi-layer, bending-resistant FPC further includes:
[0022] Providing a processing plate, the processing plate comprising the second PTFE layer, the second metal layer and the third metal layer, wherein the second metal layer and the third metal layer are respectively arranged on opposite sides of the second PTFE layer;
[0023] Attaching a carrier film to a side of the second metal layer facing away from the second PTFE layer;
[0024] removing the third metal layer;
[0025] After the core board, the two connection layers and the two sub-boards are stacked and pressed together, the carrier film is removed.
[0026] The embodiment of the present application provides a high-frequency, high-speed, multi-layer, bending-resistant FPC, which has the beneficial effect that since supporting fillers are only arranged inside the first PTFE layer of the core board, and supporting fillers are not arranged inside the second PTFE layers of the two sub-boards, the thickness of the FPC can be made smaller and the bending performance is better, thereby ensuring the normal use of the FPC. At the same time, the supporting fillers arranged inside the first PTFE layer of the core board can provide a certain supporting force for the entire FPC, thereby improving the problem of board jamming caused by excessive warping and deformation of the FPC.
[0027] The beneficial effects of the method for manufacturing a high-frequency, high-speed, multi-layer, bending-resistant FPC provided in the present application compared with the prior art can be referred to the description of the beneficial effects provided in the present application compared with the prior art, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0029] Figure 1 It is a structural schematic diagram of FPC in the related art;
[0030] Figure 2 for Figure 1 A top view of the glass fiber in the FPC shown;
[0031] Figure 3 This is a schematic diagram of the structure of an FPC in one of the embodiments of the present application;
[0032] Figure 4 yes Figure 3 A schematic diagram of the structure of the core board in the FPC shown;
[0033] Figure 5 This is a schematic diagram of the structure of a processing plate in one of the embodiments of the present application;
[0034] Figure 6 yes Figure 3 A top view of the support filler in the FPC shown;
[0035] Figure 7 It is a top view of the panelization in one of the embodiments of the present application.
[0036] The meanings of the marks in the figure are:
[0037] 1. Core board; 2. Sub-board; 3. Filler;
[0038] 1000, imposition;
[0039] 100. Unit board
[0040] 10. core plate; 11. first PTFE layer; 111. first fiber strip; 112. second fiber strip; 12. first metal layer; 13. supporting filler;
[0041] 20. Connection layer;
[0042] 30, sub-plate; 301, processing plate; 31, second PTFE layer; 32, second metal layer; 33, third metal layer;
[0043] 200, waste part; 210, process edge; 220, panel edge. DETAILED DESCRIPTION
[0044] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0045] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.
[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0047] References to "one embodiment", "some embodiments" or "an embodiment" described in the specification of this application mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some other embodiments", "in some other embodiments", etc., which appear at different places in this specification, do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. In addition, in one or more embodiments, particular features, structures or characteristics may be combined in any suitable manner.
[0048] In order to illustrate the technical solution of the present application, a description is given below with reference to specific drawings and embodiments.
[0049] In the design process of FPC (Flexible Printed Circuit) for high-frequency and high-speed signal transmission, we must not only consider how to achieve higher signal transmission efficiency and minimize the loss during signal transmission, but also make it meet the requirements of assembly and bending. Currently, there are two main structures of FPC:
[0050] The first method is to use MPI or LCP as the dielectric layer. Compared with the traditional PI medium, these two dielectric layers have the characteristics of low loss and bending resistance, but the loss will increase during signal transmission. Although it can meet the bending requirements to a certain extent, it cannot meet some FPCs with lower signal loss requirements.
[0051] The second method is to use PTFE with a thickness of more than 3 mil as the dielectric layer, which can effectively reduce the energy loss during signal transmission and improve the efficiency of signal transmission. Due to the unique softness of PTFE, in order to increase its manufacturability, some supporting fillers such as ceramic powder and glass fiber cloth are generally added to PTFE, which will increase the thickness of the dielectric layer, resulting in the thickness of the FPC being more than 0.5 mm.
[0052] For example, see Figure 1 and Figure 2The traditional FPC includes a core board 1 and two sub-boards 2, and the two sub-boards 2 are respectively arranged on both sides of the core board 1. The core board 1 and the two sub-boards 2 are filled with fillers. When the filler is glass fiber, the glass fiber includes first fiber strips and second fiber strips that are crisscrossed. The first fiber strips are parallel to the length direction of the core board 1, and the second fiber strips are parallel to the width direction of the core board 1.
[0053] Among them, the increase in FPC board thickness and the addition of fillers will cause it to be unable to achieve the bending effect, affecting normal use.
[0054] In view of this, the present application provides a high-frequency, high-speed, multi-layer, bending-resistant FPC and a method for manufacturing the same. Since supporting fillers are only arranged inside the first PTFE layer of the core board, and no supporting fillers are arranged inside the second PTFE layers of the two sub-boards, the thickness of the FPC can be made smaller and the bending performance is better, thereby ensuring the normal use of the FPC. At the same time, the supporting fillers arranged inside the first PTFE layer of the core board can provide a certain supporting force for the entire FPC, thereby improving the problem of board jamming caused by excessive warping and deformation of the FPC.
[0055] Please refer to Figure 3 , Figure 4 and Figure 5 The embodiment of the present application provides a high-frequency, high-speed, multi-layer, bending-resistant FPC, including a unit board 100 , wherein the unit board 100 includes a core board 10 , two connection layers 20 and two sub-boards 30 .
[0056] The core plate 10 includes a first PTFE layer 11 and two first metal layers 12 . The two first metal layers 12 are respectively arranged on two opposite sides of the first PTFE layer 11 . A supporting filler 13 is arranged inside the first PTFE layer 11 .
[0057] The first metal layer 12 may be a copper layer, a silver layer or an aluminum layer. The first PTFE layer 11 as an interlayer dielectric layer (insulating layer) can effectively reduce the energy loss during signal transmission, achieve low signal loss requirements, and improve the efficiency of signal transmission. The supporting filler 13 may include silicon fiber or glass fiber.
[0058] The core board 10 may have gone through processes such as dry film pasting, exposure, development, and etching to produce inner layer circuits on the first metal layer 12, and then the dry film is removed after etching. The quality of the inner layer circuit production is then inspected by AOI (Automated Optical Inspection), and then the inner layer is punched and browned. The holes here are alignment holes for combination. The hole diameter can be different from that of conventional tool holes, such as a diameter of 3.0mm for distinction. Depending on the size of the core board 10, different numbers of alignment holes can be designed on the process edge 210 to improve the alignment accuracy. The line speed requirement for browning is designed to be 2m / min-3.5m / min. The purpose is to deposit a layer of metal-bonded organic film on the surface of the inner layer circuit to increase the bonding strength with the covering film.
[0059] One of the connection layers 20 is connected to one of the first metal layers 12 , and the other connection layer 20 is connected to the other first metal layer 12 .
[0060] The connection layer 20 may include pure glue, such as epoxy resin, acrylic or hydrocarbon.
[0061] One of the sub-plates 30 is connected to one of the connection layers 20 , and the other sub-plate 30 is connected to the other connection layer 20 . The sub-plate 30 includes a second PTFE layer 31 and a second metal layer 32 . The second metal layer 32 is located on the side of the second PTFE layer 31 away from the core plate 10 .
[0062] The second metal layer 32 may be a copper layer, a silver layer or an aluminum layer. The second PTFE layer 31 serves as an interlayer dielectric layer (insulating layer), which can effectively reduce energy loss during signal transmission and improve signal transmission efficiency.
[0063] It should be noted that, in the present embodiment, the FPC is a 4-layer board structure, and the connecting layer 20 and other sub-boards 30 may be further arranged on the side of the sub-board 30 away from the core board 10, so that the FPC forms a more multi-layer structure, such as a 6-layer, 8-layer or other multi-layer FPC. In other embodiments, if the FPC is a 5-layer or 7-layer structure, it can be made by etching one copper surface according to the 6-layer or 8-layer structure. Taking the FPC as a 5-layer board as an example, a double-sided core board 10 in the middle can be used, and the upper and lower sides can be a sub-board 30 with one side being double-sided and the other side being a single-sided sub-board 30 to complete the production. Taking the FPC as a 6-layer board as an example, a double-sided core board 10 in the middle can be used, and the upper and lower sides are both double-sided sub-boards 30. After making the secondary outer layer circuit, a double-sided sub-board 30 is pressed together on each of the upper and lower sides to obtain a 6-layer board.
[0064] Among them, since PTFE material has good flexibility and bendability, although it can achieve the requirements of bendability and low loss, if the core board 10 and the two sub-boards 30 are not provided with supporting fillers 13, the FPC will be too easy to deform, which will cause the problem of card jamming when the FPC passes through the horizontal conveyor line during the production process. Therefore, it is necessary to set supporting fillers 13 in the core board 10 and the two sub-boards 30. If supporting fillers 13 are set in both the core board 10 and the two sub-boards 30, the bending performance requirements cannot be met.
[0065] When the middle part of the FPC is bent upward or downward, the deformation of the two sub-boards 30 is the largest, while the deformation of the middle core board 10 is smaller. For example, when the middle part of the FPC is bent downward, the upper sub-board 30 is subjected to the largest extrusion force, the lower sub-board 30 is subjected to the largest tensile force, and the compression and stretching of the middle core board 10 are the smallest, so that most of the stress is absorbed by the outer sub-board 30.
[0066] Therefore, only by setting the supporting filler 13 inside the first PTFE layer 11 of the core board 10, the tensile strength, bending strength and bending modulus of the core board 10 can be increased, and the production of the core board 10 becomes easy, and the expansion and contraction of the core board 10 can be relatively stable. No supporting filler 13 is set in the second PTFE layer 31 of the two sub-boards 30, and the bending performance of the two sub-boards 30 is greatly improved, so that the thickness of the FPC can be smaller and the bending performance is better, thereby ensuring the normal use of the FPC, and also enabling the supporting filler 13 to provide a certain supporting force.
[0067] The method for manufacturing a high-frequency, high-speed, multi-layer, bending-resistant FPC provided in an embodiment of the present application includes:
[0068] The core board 10 , two connection layers 20 and two sub-boards 30 are stacked and pressed together.
[0069] Specifically, it can be achieved by stacking plates and transmitting pressure.
[0070] Stacking and assembling the boards: stack the core board 10, the connection layer 20 and the sub-board 30 with PIN holes in sequence on the hot melt machine and rivet them together. The PIN holes need to be inserted into the pins of the hot melt machine so that all the layers form a whole. Stack them in sequence and wait for assembly.
[0071] Then, a vacuum air bag press is used to place the fused whole into a vacuum press with the temperature set at 130°C and the time set at 60 seconds. A release film is placed on the top and bottom to prevent the edge of the board from overflowing and sticking to the hot plate of the vacuum press after hot pressing.
[0072] Pressure transmission: The buffer material, the assembled whole, and the buffer material need to be stacked in the BOOK (opening) of the pressure transmission machine in sequence. The buffer material can be selected from PE (Polyethylene) film, adhesive-resistant film, PACO PAD (paper pressing pad), three-in-one, etc. The remaining layers are stacked in sequence according to the above structure. The constant temperature section of the pressure transmission parameters is set according to the technical parameters of pure glue. The constant temperature time of the high temperature and high pressure section must not be less than 90 minutes. The starting temperature of the heating section is 40°C, and the heating rate can be set to 2°C / min-4°C / min. When the cooling section drops to 40°C, the cooling rate is set to 4°C / min-8°C / min. The pressure reaches full pressure at 1 / 3 of the Tg value, and the pressure area value needs to be 1.4 times larger than the actual value to ensure that there is no risk of underpressure.
[0073] From the above, it can be seen that the embodiment of the present application provides a high-frequency, high-speed, multi-layer, bending-resistant FPC. Since the supporting filler 13 is only arranged inside the first PTFE layer 11 of the core board 10, and no supporting filler 13 is arranged in the second PTFE layer 31 of the two sub-boards 30, the thickness of the FPC can be made smaller and the bending performance is better, thereby ensuring the normal use of the FPC. At the same time, the supporting filler 13 arranged inside the first PTFE layer 11 of the core board 10 can provide a certain supporting force for the entire FPC, thereby improving the board jamming problem caused by excessive warping deformation of the FPC, improving production feasibility and improving yield.
[0074] Optionally, when the connection layer 20 includes pure glue, it can be manufactured through processes such as cutting and drilling.
[0075] Cutting: Cut the pure glue used for bonding to 3mm smaller than the overall size of the core board 10 to reduce glue overflow after pressing.
[0076] Drilling: Drill the fused alignment holes.
[0077] Then, the pure glue is adhered to the sub-board 30 through the alignment holes, and the sub-board 30 and the pure glue are pre-fixed by false pressing.
[0078] Optionally, the supporting filler 13 includes silicon fiber or glass fiber.
[0079] Such an arrangement can make the structure of the supporting filler 13 relatively simple, and facilitate the arrangement of the supporting filler 13 .
[0080] Please refer to Figure 5 and Figure 6 In this embodiment, the supporting filler 13 includes first fiber strips 111 and second fiber strips 112 that are interwoven in a vertical and horizontal direction. The extending direction of the first fiber strips 111 is neither parallel nor perpendicular to the long side direction of the core plate 10 .
[0081] By adopting the above-mentioned scheme, when the supporting filler 13 is subjected to external force during the bending process of the FPC, the first fiber strip 111 and the second fiber strip 112 can better withstand and disperse the stress, thereby improving the overall strength and toughness of the supporting filler 13, effectively reducing stress concentration, and avoiding cracks or breakage of the supporting filler 13 when subjected to force, further enhancing the durability and reliability of the supporting filler 13, and then significantly increasing the bending performance of the first PTFE layer 11, making it more suitable for application scenarios that need to withstand bending stress.
[0082] It is understandable that the extension direction of the first fiber strip 111 is perpendicular to the extension direction of the second fiber strip 112, and the core board 10 can generally be set as a cuboid or a cube. Since the extension direction of the first fiber strip 111 is not parallel to and perpendicular to the long side direction of the core board 10, the extension direction of the second fiber strip 112 is also not parallel to and perpendicular to the long side direction of the core board 10.
[0083] Optionally, the angle between the extension direction of the first fiber strip 111 and the long side direction of the core plate 10 is 45°, 50° or 60°.
[0084] Such an arrangement enables the first fiber strips 111 and the second fiber strips 112 to better withstand and disperse stress, thereby improving the overall strength and toughness of the supporting filler 13 .
[0085] In this embodiment, the included angle between the extending direction of the first fiber strip 111 and the long side direction of the core plate 10 is 45°.
[0086] Such an arrangement enables the first fiber strips 111 and the second fiber strips 112 to better withstand and disperse stress, thereby improving the overall strength and toughness of the supporting filler 13 .
[0087] From the above analysis, it can be seen that in the process of bending the middle part of the FPC upward or downward, the deformation of the two sub-boards 30 is the largest, while the deformation of the middle core board 10 is smaller. In order to prevent the force exerted on the supporting filler 13 from changing significantly in the process of bending the middle part of the FPC upward and downward, in this embodiment, the two sub-boards 30 are symmetrically arranged with the supporting filler 13 as the center.
[0088] By adopting the above solution, the force applied to the supporting filler 13 will not change significantly during the process of bending the middle portion of the FPC upward and downward, and the supporting filler 13 will not significantly affect the bending performance of the FPC.
[0089] Optionally, in the arrangement direction of the two first metal layers 12 , the supporting filler 13 separates the first PTFE layer 11 into two parts with the same thickness.
[0090] With such arrangement, the force applied to the supporting filler 13 will not change significantly during the process of bending the middle portion of the FPC upward and downward, and the supporting filler 13 will be more evenly applied with the force.
[0091] It should be noted that the FPC may be a symmetrical structure with the supporting filler 13 as the symmetry center, and the FPC has better bending resistance.
[0092] Please refer to Figure 3 , Figure 4 and Figure 7 In this embodiment, before the core board 10, the two connection layers 20 and the two sub-boards 30 are stacked and pressed together, the method for manufacturing the high-frequency, high-speed, multi-layer, bending-resistant FPC further includes:
[0093] First, a panel 1000 is provided, which includes multiple waste parts 200 and a unit board 100. The panel has a molding line, and the unit board 100 and the waste part 200 are separated by the molding line. The waste part 200 includes a process edge 210 located at the edge of the panel 1000 and / or a panel edge 220 located between two adjacent unit boards 100. The process edge 210 is provided with a reinforcing metal layer on the same layer as the first metal layer 12 and / or the second metal layer 32.
[0094] Next, the panel 1000 is divided into a plurality of unit panels 100 along the forming lines.
[0095] By adopting the above solution, the strength of the plateset 1000 can be improved by using a reinforced metal layer, thereby avoiding the problem of plate jamming caused by excessive warping and deformation of the plateset 1000 when passing through a horizontal conveyor line.
[0096] It is understandable that the process of dividing the panel 1000 into a plurality of unit panels 100 may be a molding process, and the reinforcing metal layer needs to be removed during the molding process. The reinforcing metal layer may be a copper layer, a silver layer or an aluminum layer, and the reinforcing metal layer may be made of the same material as the first metal layer 12 .
[0097] Optionally, the distance between the reinforcing metal layer and the forming line is greater than or equal to 5 mm.
[0098] Such a configuration can prevent the reinforced metal layer from affecting the process of dividing the panel 1000 into a plurality of unit panels 100 .
[0099] It can be understood that when multiple layers of the reinforcing metal layer are provided, the distance between each reinforcing metal layer and the forming line is greater than or equal to 5 mm.
[0100] For example, the reinforcing metal layer on the same layer as the first metal layer 12 and the reinforcing metal layer on the same layer as the second metal layer 32 can be symmetrically arranged to reduce the card jamming problem caused by the FPC warping and other problems caused by the stress between the FPC layers.
[0101] When the AOI detects the quality of the inner layer circuit, it can also detect that the reinforcing metal layer of the waste portion 200 is not connected to the first metal layer 12 of the core board 10 .
[0102] Please refer to Figure 3 , Figure 4 and Figure 5 In this embodiment, before the core board 10, the two connection layers 20 and the two sub-boards 30 are stacked and pressed together, the method for manufacturing the high-frequency, high-speed, multi-layer, bending-resistant FPC further includes:
[0103] First, a processing plate 301 is provided. The processing plate 301 includes a second PTFE layer 31 , a second metal layer 32 and a third metal layer 33 . The second metal layer 32 and the third metal layer 33 are respectively arranged on opposite sides of the second PTFE layer 31 .
[0104] The processing plate 301 may be a double-sided substrate cut out according to required dimensions.
[0105] Next, a carrier film is attached to a side of the second metal layer 32 facing away from the second PTFE layer 31 .
[0106] Then, the third metal layer 33 is removed.
[0107] Specifically, the third metal layer 33 can be removed by etching. The third metal layer 33 can be removed by dry film application, exposure, development, and etching. Dry film application, exposure, and development are performed on the surface of the third metal layer 33 to expose the third metal layer 33, and the reinforcement metal layer is covered by dry film exposure, and then the first metal layer 12 is etched away by etching, and then the dry film is removed to obtain a single-sided daughter board 30.
[0108] After the core board 10 , the two connection layers 20 and the two sub-boards 30 are stacked and pressed together, the carrier film is removed to obtain the sub-boards 30 .
[0109] By adopting the above solution, the sub-board 30 can be easily manufactured, and the carrier film can be used as a support for the processing board 301, and the second metal layer 32 can be protected to prevent damage to the second metal layer 32 when the third metal layer 33 is removed.
[0110] Among them, the carrier film can be resistant to acid and alkali, high temperature and high pressure, without adhesive layer dissolution, and without residual adhesive after lamination. The carrier film can be a PI film, etc. After removing the carrier film, X-ray drilling, outer layer production and post-processing can be continued, all of which are completed in the conventional production method.
[0111] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.
Claims
1. A high-frequency, high-speed, multi-layer, bending-resistant FPC, characterized in that: The invention comprises a unit plate, wherein the unit plate comprises: A core plate, the core plate comprising a first PTFE layer and two first metal layers, the two first metal layers are respectively arranged on two opposite sides of the first PTFE layer, and a supporting filler is arranged inside the first PTFE layer; Two connection layers, one of the connection layers is connected to one of the first metal layers, and the other connection layer is connected to the other first metal layer; Two sub-plates, one of which is connected to one of the connecting layers, and the other of which is connected to the other of the connecting layers, wherein the sub-plates include a second PTFE layer and a second metal layer, wherein the second metal layer is located on a side of the second PTFE layer away from the core plate.
2. The high-frequency, high-speed, multi-layer, bending-resistant FPC according to claim 1, characterized in that: The supporting filler includes silicon fiber or glass fiber.
3. The high-frequency, high-speed, multi-layer, bending-resistant FPC according to claim 2, characterized in that: The supporting filler includes first fiber strips and second fiber strips that are interwoven vertically and horizontally, and the extending direction of the first fiber strips is neither parallel nor perpendicular to the long side direction of the core plate.
4. The high-frequency, high-speed, multi-layer, bending-resistant FPC according to claim 3, characterized in that: The included angle between the extension direction of the first fiber strip and the long side direction of the core plate is 45°, 50° or 60°.
5. The high-frequency, high-speed, multi-layer, bending-resistant FPC according to any one of claims 1 to 4, characterized in that: The two sub-plates are symmetrically arranged with the supporting filler as the center.
6. The high-frequency, high-speed, multi-layer, bending-resistant FPC according to claim 5, characterized in that: In the arrangement direction of the two first metal layers, the supporting filler separates the first PTFE layer into two parts with the same thickness.
7. A method for manufacturing a high-frequency, high-speed, multi-layer, bending-resistant FPC as claimed in any one of claims 1 to 6, characterized in that: include: The core board, the two connection layers and the two sub-boards are stacked and pressed together.
8. The method for manufacturing a high-frequency, high-speed, multi-layer, bending-resistant FPC according to claim 7, characterized in that: Before stacking and pressing the core board, the two connection layers and the two sub-boards together, the method for manufacturing the high-frequency, high-speed, multi-layer, bending-resistant FPC further includes: Providing a panel, the panel comprising a waste part and a plurality of the unit boards, the panel having a molding line, the unit boards and the waste part being separated by the molding line, the waste part comprising a process edge located at an edge of the panel and / or a panel edge located between two adjacent unit boards, the process edge being provided with a reinforcing metal layer in the same layer as the first metal layer and / or the second metal layer; The panel is divided into a plurality of unit panels along the forming line.
9. The method for manufacturing a high-frequency, high-speed, multi-layer, bending-resistant FPC according to claim 8, characterized in that: The distance between the reinforcing metal layer and the forming line is greater than or equal to 5 mm.
10. The method for manufacturing a high-frequency, high-speed, multi-layer, bending-resistant FPC according to any one of claims 7 to 9, characterized in that: Before stacking and pressing the core board, the two connection layers and the two sub-boards together, the method for manufacturing the high-frequency, high-speed, multi-layer, bending-resistant FPC further includes: Providing a processing plate, the processing plate comprising the second PTFE layer, the second metal layer and the third metal layer, wherein the second metal layer and the third metal layer are respectively arranged on opposite sides of the second PTFE layer; Attaching a carrier film to a side of the second metal layer facing away from the second PTFE layer; removing the third metal layer; After the core board, the two connection layers and the two sub-boards are stacked and pressed together, the carrier film is removed.