System and method for manufacturing a flexible flat cable

Abstract

Roll-to-roll flexible circuit manufacturing processes may be used to manufacture FFC or flexible circuit products. The processes use laser ablation techniques to generate layer patterns. A roll-to-roll process may be performed to manufacture a flexible flat cable having conductive traces that have different widths and also have openings, such as pads, at desired locations.

Description

Technical Field

[0001] The present invention relates to a system and method for manufacturing a flexible flat cable (FFC), and more particularly, to a method for manufacturing an FFC using a roll-to-roll process. Background Art

[0002] Conventional manufacturing processes for FFCs have several limitations and disadvantages. One disadvantage is that there are limitations on the size of the traces that can be manufactured. In particular, the traces are limited in several dimensions, which may include their width, their length, and their thickness. Another disadvantage is that the traces have limited current carrying capacity, which is caused by the limitations on the width and thickness of the traces. Another disadvantage is that conventionally manufactured traces have limited compatibility with connector connections due to the spacing of the traces and the thinness of the traces.

[0003] Another disadvantage is that the traces have spatial limitations due to the industry's usual requirement for uniform trace width and length. In addition, conventional traces lack the flexibility of having openings (such as pads) in the middle of the cable for electrical connections. Another disadvantage is the waste of materials such as aluminum, which increases the cost of the finished product.

[0004] Therefore, there is a need for a method for manufacturing FFC that solves the above-mentioned disadvantages. Summary of the invention

[0005] Reel-to-reel flexible circuit manufacturing processes can be used to manufacture FFC or flexible circuit products. These processes use laser ablation technology to generate layer patterns. Reel-to-reel processes can be performed to manufacture flexible flat cables with conductive traces that have different widths and also have openings at desired locations, such as pads.

[0006] In one aspect of the present disclosure, a method for manufacturing a flexible circuit includes a method for manufacturing a flexible flat cable, the method including the steps of: providing a first material; cutting the first material into a first trace and a second trace; dividing the first trace and the second trace; providing a second material, the second material being a cover layer; providing a third material, the third material being a cover layer; laminating both the second material and the third material to the first trace and the second trace to form a laminated product; and cutting the laminated product.

[0007] In one aspect of the disclosure, the first trace has a length and a width, and the width is variable along the length of the first trace.

[0008] In another aspect of the present disclosure, the first material is aluminum.

[0009] In another aspect of the present disclosure, the third material is the same as the second material.

[0010] In another aspect of the present disclosure, each of the second material and the third material is polyethylene terephthalate (PET).

[0011] In another aspect of the present disclosure, the first trace and the second trace have a top side and a bottom side opposite the top side, the step of providing the second material includes positioning the second material near the top side, and the step of providing the third material includes positioning the third material near the bottom side.

[0012] In another aspect of the present disclosure, the method further comprises the step of patterning the laminated product.

[0013] In another aspect of the present disclosure, the laminate product has a top side and an opposing bottom side, and the step of patterning the laminate product includes forming an opening in the top side of the laminate product, the opening being located adjacent one of the first trace or the second trace.

[0014] In another aspect of the present disclosure, the method further includes the steps of: cutting the laminated product; and scanning the laminated product after the laminated product is cut.

[0015] In another aspect of the present disclosure, the step of segmenting the first trace and the second trace includes segmenting the first trace and the second trace using a spacing roller.

[0016] In different aspects of the present disclosure, a method of manufacturing a flexible flat cable or a flexible circuit includes the following steps: providing a first material; cutting the first material into a first trace and a second trace; dividing the first trace and the second trace; providing a second material near the first trace and the second trace; providing a third material near the first trace and the second trace; laminating both the second material and the third material to the first trace and the second trace to form a laminated product; and cutting the laminated product.

[0017] In one aspect of the disclosure, the first trace has a length and a width, and the width is variable along the length of the first trace.

[0018] In one aspect of the present disclosure, the first material is aluminum, and each of the second material and the third material is polyethylene terephthalate.

[0019] In another aspect of the present disclosure, the first trace and the second trace have a top side and a bottom side opposite the top side, the step of providing the second material includes positioning the second material near the top side, and the step of providing the third material includes positioning the third material near the bottom side.

[0020] In another aspect of the present disclosure, the laminate product has a top side and an opposing bottom side, and the method further includes the step of patterning the laminate product by forming an opening in the top side of the laminate product, the opening being located adjacent one of the first trace or the second trace.

[0021] In another aspect of the present disclosure, the step of segmenting the first trace and the second trace includes segmenting the first trace and the second trace using a spacing roller.

[0022] In different aspects of the present disclosure, a flexible flat cable includes a first trace formed of a first material, the first trace having a certain length and a variable width along its length; a second trace formed of the first material, the second trace being separated from the first trace; a first cover layer made of a second material, the first cover layer being laminated to the top sides of the first trace and the second trace; and a second cover layer made of the second material, the second cover layer being laminated to the bottom sides of the first trace and the second trace, wherein the first cover layer, the second cover layer, the first trace and the second trace together form a laminated product.

[0023] In one aspect of the present disclosure, the first material is aluminum and the second material is polyethylene terephthalate.

[0024] In another aspect of the present disclosure, the laminate product has a top side and an opposing bottom side, the top side of the laminate product having an opening formed therein.

[0025] In another aspect of the present disclosure, the opening is proximate one of the first trace or the second trace. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to complete the description and to provide a better understanding of the present application, a set of drawings is provided. The drawings form an integral part of the specification and illustrate embodiments of the present application, which should not be interpreted as limiting the scope of the invention, but are merely examples. The drawings include the following:

[0027] Figure 1 A schematic diagram of an embodiment of a manufacturing system for an FFC according to one aspect of the present disclosure is shown.

[0028] Figure 2 A schematic perspective view of an embodiment of an FFC according to one aspect of the present disclosure is shown.

[0029] Figure 3 A schematic perspective view of another embodiment of an FFC according to an aspect of the present disclosure is shown.

[0030] Figure 4 A top view of an embodiment of a pair of traces according to one aspect of the present disclosure is shown.

[0031] Figure 5 A top view of another embodiment of a pair of traces according to one aspect of the present disclosure is shown.

[0032] Figure 6 An exemplary method of manufacturing an FFC according to one aspect of the present disclosure is shown.

[0033] Like reference numerals are used to identify like elements throughout this disclosure. DETAILED DESCRIPTION

[0034] The following description should not be taken in a limiting sense but is given only for the purpose of describing the broad principles of the invention. Embodiments of the invention will be described by way of example with reference to the above-mentioned drawings showing elements and results according to the invention.

[0035] In one aspect of the present disclosure, limitations on trace width and length in an FFC are overcome by the disclosed process. The steps of loading a roll of aluminum onto a reel and then cutting the aluminum using a cutting device such as a laser are included in the process. The cutting device can be used to cut the width of the aluminum as desired, either a constant width along the length of the trace or a variable width along the length of the trace, which enables different trace widths to be manufactured in a single FFC. In addition, the length of the trace can be cut using the same cutting device or different cutting devices as needed. By being able to vary the width and length of the trace, greater design flexibility for the FFC is achieved.

[0036] Limitations on current carrying capacity in FFCs are also overcome. By manufacturing traces with different widths, some traces can be made wider than other traces. Wider traces that can carry high currents can be used in the finished product for higher current rating requirements, and narrower traces can be used for lower current rating requirements. Thus, limitations on current carrying capacity are addressed by being able to manufacture wider traces as well as traces of variable width. Thus, wider traces can be used where high current is required.

[0037] It is desirable for products having traces to have the ability to make electrical connections. As described above, the manufacturing process involves removing the insulator layer in certain areas to provide the ability to make electrical connections to the traces. Therefore, by being able to ablate the insulator layer anywhere along the trace, electrical connections can be made anywhere along the cable by laser welding or brazing to the conductor layer.

[0038] By improving the ability to form openings for electrical connections anywhere along the cable, different connections can be made along the FFC. Connections can be made by creating openings or pads along the traces. Openings on the traces can be laser welded or soldered. As a result, connector compatibility is not limited to FFC connectors and overall compatibility with connectors is enhanced.

[0039] In one embodiment according to the present disclosure, a method for roll-to-roll production of FFC is described. In this process, an aluminum roll having a desired width is loaded onto a reel. As the aluminum is unwound from the reel, the aluminum is precisely cut into flat traces having a desired width (whether constant width or variable width) by a cutting device such as a laser. The flat traces may alternatively be referred to as conductive traces.

[0040] In different embodiments, the process may include a waste removal process, or it may rely solely on laser ablation. Either way, the flat cut traces are separated by spacing rollers to achieve the desired spacing.

[0041] After the cut traces are separated, thermosetting PET is applied and laminated to the top and bottom of the conductor traces, acting as an insulating and protective layer for the traces. In areas where connections are required, laser ablation is used to remove the PET layer from the top and bottom of the conductive traces, exposing them for electrical connections.

[0042] In some finished products, electrical connections to flat traces are required. In areas where such electrical connections are required, the manufacturing process utilizes laser ablation to remove the PET layer from both the top and bottom sides of the conductive traces. As a result, the PET material removed in specific areas provides exposure and access to the conductive traces so that electrical connections can be made thereto.

[0043] First go to Figure 1 , shows an exemplary manufacturing system according to the present disclosure. This manufacturing system is used to manufacture flexible flat cables. In this embodiment, the manufacturing system 10 includes three raw material sources. One raw material is aluminum 20, which can be loaded onto a reel. The other two raw materials are PET, which can also be loaded onto a reel. Different materials are continuously supplied to the manufacturing system 10.

[0044] PET material 30 may be located on one side of the aluminum trace, such as the top side of the aluminum trace, and PET material 40 may be located on the opposite side of the aluminum trace, such as the bottom side of the aluminum trace. As described below, PET is laminated to opposite sides of the trace.

[0045] The system 10 includes a cutting device 100, such as a laser, which cuts the aluminum 20 into individual traces having a constant width or a variable width. After the aluminum 20 is cut into individual traces, the cut traces are separated by one or more spacing rollers 110. In different embodiments, the size and configuration of each spacing roller 110 can vary. In this embodiment, there is a spacing roller 110 located on the upper surface or side of the aluminum 20, and another spacing roller 110 located on the lower surface or side of the aluminum 20. In one embodiment, a drive mechanism such as a motor with a gear box can be actuated to drive one or both of the spacing rollers 110. It should be understood that in different embodiments, only one of the spacing rollers 110 can be actively driven, while the other of the spacing rollers 110 is not actively driven.

[0046] The separated cutting traces are moved or directed to laminating stations 120 and 122 in the system 10. The PET roller 30 supplies a layer of PET material to the laminating station 120, wherein the PET material 30 is laminated on the top side or top surface of the cutting traces. At the same time, the PET roller 40 supplies a layer of PET material to another laminating station 122, wherein the PET material 40 is laminated on the bottom side or bottom surface of the cutting traces. The resulting product leaving the laminating process at the laminating stations 120 and 122 is a laminated product having traces located between the PET material layers 30 and 40.

[0047] The laminated product is then transported to a location near one or more cutting devices such as lasers, which perform patterning of the PET material. In this embodiment, a cutting device 130 is located near the upper surface or side of the laminated product, and another cutting device 132 is located near the lower surface or side of the laminated product. Cutting devices 130 and 132 are used to cut the laminated product into multiple parts with desired width and length. In addition, cutting devices 130 and 132 are used to ablate one or more specific areas to remove a selected amount of PET material to form an opening, which causes the aluminum layer or trace to be exposed. After ablation occurs, cutting devices 130 and 132 are used to perform any additional cutting on the laminated product so that the FFC piece has the desired length.

[0048] In one embodiment, the cut FFC products are then advanced to a scanner 140, such as a laser scanner, which performs a quality inspection of the FFC products. The scanner 140 inspects the shape of the FFC products and confirms that the openings in the FFC products are in their proper locations.

[0049] refer to Figure 2 and Figure 3 , showing schematic perspective views of various embodiments of the FFC according to the present disclosure. Figure 2, the FFC product 200 includes a body 210 formed of PET material layers 220 and 230, which are laminated to opposite sides of the trace ( Figure 2 2). The body 210 has a top side or surface 212 and an opposite bottom side or surface 214. In this embodiment, the body 210, and in particular the top side 212, has an opening 240 formed therein as a result of the patterning process briefly discussed above. There may be more than one opening 240 in the PET material layer 220, and there may be one or more openings formed in the lower surface of the FFC product 200 in the PET material layer 230. The FFC product 200 has a width W1 and a length L1. In some embodiments, the width W1 may be constant along the length of the FFC product 200.

[0050] First go to Figure 3 , the FFC product 300 includes a body 310 formed of PET material layers 320 and 330, which are laminated to opposite sides of the trace ( Figure 3 310). The body 310 has a top side or surface 312 and an opposite bottom side or surface 314. In this embodiment, the body 310, and in particular the top side 312, has two openings 340 and 350 formed therein as a result of the patterning process briefly discussed above. There may be one or more openings formed in the lower surface of the FFC product 300 in the PET material layer 330. The FFC product 300 has a width W2 and a length L2.

[0051] In some embodiments, the width W1 of the FFC product 200 is different from the width W2 of the FFC product 300. In various embodiments, the width W1 may be greater than or less than the width W2. In other embodiments, the widths W1 and W2 may be the same. Similarly, in some embodiments, the length L1 of the FFC product 200 is different from the length L2 of the FFC product 300. In various embodiments, the length L1 may be greater than or less than the length L2. In other embodiments, the lengths L1 and L2 may be the same.

[0052] Go to Figure 4 , shows an embodiment of a pair of traces according to one aspect of the present disclosure. In this embodiment, pair 360 includes a first trace 362 and a second trace 364. First trace 362 has a length L3 and a width W3, and second trace 364 has a length L4 and a width W4. The width W3 of trace 362 is constant along the length L3. Similarly, the width W4 of trace 364 is constant along the length L4. It should be understood that although two traces 362 and 364 are shown, the aluminum material can be divided into more than two traces.

[0053] Go to Figure 5 , another embodiment of a pair of traces according to one aspect of the present disclosure is shown. In this embodiment, pair 370 includes a first trace 372 and a second trace 374. The first trace 372 has a length L5 and a width W5, and the second trace 374 has a length L6 and a width W6. The width W5 of trace 372 varies along the length L5. Similarly, the width W6 of trace 374 varies along the length L6. It should be understood that although two traces 372 and 374 are shown, the aluminum material can be divided into more than two traces. Moreover, in different embodiments, the widths W5 and W6 and the shapes of traces 372 and 374 can vary as desired.

[0054] refer to Figure 6 , shows an exemplary embodiment of a manufacturing process according to one aspect of the present invention. The process is used to manufacture FFC.

[0055] In this embodiment, manufacturing process 400 comprises several steps, and these steps are exemplary.Process 400 begins at step 410, and it relates to material unwinding.In one embodiment, a large supply reel is loaded, and the reel comprises a roll of aluminum and two rolls of PET.The PET roller is located on the opposite side of the aluminum, so that the PET roller is located on the opposite side of the aluminum material for lamination process.One of the PET rollers is positioned and guided near the bottom side of the aluminum material, and another PET material roll is positioned and guided to be adjacent to the top side of the aluminum material.The aluminum material can be pulled out from its reel and guided to the cutting device.

[0056] Turning to step 412, this step involves laser cutting the aluminum material. The aluminum material is removed from its roll and cut into individual traces using a laser. The individual traces are cut to a desired width, which can be a constant width or a variable width for a given trace length.

[0057] After the cutting process in step 412, the cutting traces are separated in step 414. In one embodiment, the cutting traces are separated into certain pitches by a pitch roller.

[0058] Going to step 416, the lamination process is performed. Once the traces are separated into their desired arrangement and configuration, the lamination process occurs. The aluminum traces pass through a lamination station to add a layer of PET material to the top and bottom sides of each trace. The PET material layer is a protective and insulating layer located on the top and bottom sides of each trace.

[0059] In step 418, a patterning process is performed on the laminated PET and trace material. The patterning process is performed after the PET material has been laminated to the aluminum trace. The laminated PET and aluminum material is cut to a desired width and a desired length. The PET material is then ablated in certain areas to expose the aluminum layer or trace and form openings or pads for electrical connection to the trace.

[0060]

[0046] Moving to step 420, after the PET material has been added and ablated, if applicable, the PET material is laser cut at the desired length.

[0061] In step 422, after cutting is completed, the FFC passes through a laser scanner to check the shape of the board and the positioning of the opening positions. The shape inspection and position inspection are part of the quality inspection process.

[0062] The final step in process 400 is step 424, where the finished product is collected onto a reel.

[0063] Compared with the rotary die laser cutting FPC process, the manufacturing process disclosed herein reduces material waste. In the disclosed process, aluminum is laser cut and separated, replacing the traditional process of cutting and removing material at the wasteful trace spacing location.

[0064] In alternative embodiments of the manufacturing process, the aluminum material can be replaced by any similar material, including but not limited to nickel-plated aluminum, nickel or stainless steel. Similarly, the PET material can be replaced by alternative materials, including but not limited to polyimide (PI), polypropylene (PP), polyethylene naphthalate (PEN) and polyetherimide (PEI).

[0065] In another embodiment of the manufacturing process, the laser cutting of the traces to a specific length can be replaced by performing a V-cut, where the aluminum material is deeply cut but not completely separated. In one embodiment, instead of a laser, a blade or equivalent device can be used to mechanically cut the material.

[0066] Reference is made herein to the relative location of materials in terms of the "top side" or the "bottom side." It should be understood that while "top" or "bottom" are used to describe where materials are located, alternative arrangements of "bottom" or "top" are also contemplated. Furthermore, while the term "laser" is referenced, any suitable cutting device may be used to perform the referenced cutting and ablation, so long as the cutting device can appropriately and accurately make the desired cuts in one or more layers.

[0067] Although the present invention has been illustrated and described in detail and with reference to its specific embodiments, the present invention is not intended to be limited to the details shown, as it is apparent that various modifications and structural changes may be made therein without departing from the scope of the present invention and within the scope and range of equivalents of the claims. In addition, various features from one of the embodiments may be incorporated into another in the embodiments. Therefore, it is appropriate that the appended claims be interpreted broadly and in a manner consistent with the scope of the present disclosure set forth in the appended claims.

[0068] Similarly, the present invention is intended to cover modifications and variations of the present invention that fall within the scope of the appended claims and their equivalents. For example, it should be understood that terms such as "left", "right", "top", "bottom", "front", "back", "side", "height", "length", "width", "up", "down", "interior", "exterior", "inside", "outside", etc. that may be used herein only describe reference points and do not limit the present invention to any particular orientation or configuration. In addition, the term "exemplary" is used herein to describe an example or illustration. Any embodiment described herein as exemplary should not be construed as a preferred or advantageous embodiment, but rather as an example or illustration of a possible embodiment of the present invention.

[0069] Finally, when used in this article, the term "include" and its derivatives (such as "comprising", etc.) should not be understood in an exclusive sense, that is, these terms should not be interpreted as excluding the possibility that the described and defined content can include other elements, steps, etc. At the same time, when used in this article, the term "approximately" and its cognate terms (such as "approximately", etc.) should be understood to indicate a value that is very close to the value accompanying the preceding term. That is, deviations from the exact value within reasonable limits should be accepted, because those skilled in the art will understand that such deviations from the indicated values ​​are inevitable due to measurement inaccuracies, etc. The same applies to the terms "about" and "approximately" and "substantially".

Claims

1. A method for manufacturing a flexible flat cable, the method comprising the following steps: providing the first material; cutting the first material into a first trace and a second trace; splitting the first trace and the second trace; providing a second material, the second material being a cover layer; providing a third material, the third material being a cover layer; laminating both the second material and the third material to the first trace and the second trace to form a laminated product; as well as The laminated product is cut. 2 . The method of claim 1 , wherein the first trace has a length and a width, and the width is variable along the length of the first trace. The method of claim 1 , wherein the first material is aluminum. The method of claim 1 , wherein the third material is the same as the second material. 5 . The method of claim 4 , wherein each of the second material and the third material is polyethylene terephthalate (PET).

6. The method of claim 1 , wherein the first trace and the second trace have a top side and a bottom side opposite the top side, the step of providing a second material comprises positioning the second material near the top side, and the step of providing a third material comprises positioning the third material near the bottom side.

7. The method according to claim 1, further comprising the steps of: The laminated product is patterned.

8. The method of claim 7, wherein the laminate product has a top side and an opposing bottom side, and the step of patterning the laminate product includes forming an opening in the top side of the laminate product, the opening being located adjacent one of the first trace or the second trace.

9. The method according to claim 7, further comprising the steps of: cutting the laminated product; and The laminated product is scanned after the laminated product is cut.

10. The method of claim 9, wherein the step of segmenting the first trace and the second trace comprises segmenting the first trace and the second trace using a spacing roller.

11. A method for manufacturing a flexible flat cable or a flexible circuit, the method comprising the following steps: providing the first material; cutting the first material into a first trace and a second trace; splitting the first trace and the second trace; providing a second material proximate the first trace and the second trace; providing a third material proximate the first trace and the second trace; laminating both the second material and the third material to the first trace and the second trace to form a laminated product; as well as The laminated product is cut.

12. The method of claim 11, wherein the first trace has a length and a width, and the width is variable along the length of the first trace.

13. The method of claim 11, wherein the first material is aluminum, and each of the second material and the third material is polyethylene terephthalate.

14. The method of claim 11, wherein the first trace and the second trace have a top side and a bottom side opposite the top side, the step of providing a second material includes positioning the second material near the top side, and the step of providing a third material includes positioning the third material near the bottom side.

15. The method of claim 11, wherein the laminate product has a top side and an opposing bottom side, and the method further comprises the steps of: The laminate product is patterned by forming an opening in a top side of the laminate product, the opening being located proximate one of the first trace or the second trace.

16. The method of claim 11, wherein the step of segmenting the first trace and the second trace comprises segmenting the first trace and the second trace using a spacing roller.

17. A flexible flat cable, comprising: a first trace formed of a first material, the first trace having a length and a variable width along its length; a second trace formed of the first material, the second trace being separate from the first trace; a first cover layer made of a second material, the first cover layer being laminated to a top side of the first trace and the second trace; as well as A second cover layer made of the second material is laminated to the bottom sides of the first and second traces, wherein the first cover layer, the second cover layer, the first trace and the second trace together form a laminated product.

18. The flexible flat cable of claim 17, wherein the first material is aluminum and the second material is polyethylene terephthalate.

19. The flexible flat cable of claim 17, wherein the laminate product has a top side and an opposing bottom side, the top side of the laminate product having an opening formed therein.

20. The flexible flat cable of claim 19, wherein the opening is adjacent one of the first trace or the second trace.

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