The structure and manufacturing process of a flexible flat cable

Abstract

This invention relates to the structure and manufacturing process of a flexible flat cable, belonging to the technical field of electrical connection systems for battery modules. The cable includes a main flexible cable busbar, solder pad areas connected to both sides of the main flexible cable busbar, a base film covering the entire structure formed by the main flexible cable busbar and the solder pad areas, and a surface cover film covering the base film. Both the base film and the surface cover film have openings for accommodating wiring to the solder pad areas. This invention provides a flexible flat cable structure that can effectively reduce production costs and avoid assembly errors that are prone to occur during manual wiring of wire harnesses.

Description

Technical Field

[0001] This application belongs to the technical field of electrical connection systems for battery modules, and specifically relates to the structure and manufacturing process of a flexible flat cable. Background Technology

[0002] Flexible flat cable (FFC) is a signal transmission component. It has advantages such as being flexible and having high signal transmission capability, so it is widely used in many electronic products. The flexible flat cable is used in conjunction with electrical connectors to transmit signals from one end to the other to achieve the purpose of signal transmission.

[0003] Under normal circumstances, flexible flat cables only have the function of conduction, and can only transmit circuit signals from one end to the other through the internal parallel metal conductors. When the spacing between the parallel metal conductors in the flexible flat cable is different from the spacing of the terminals of the electrical connector, an adapter plate is usually added between the flexible flat cable and the electrical connector for circuit conversion. This adapter plate needs to be fixed to the flexible flat cable by soldering.

[0004] To solve the problem of inability to connect via jumpers, in the prior art of a flexible ribbon cable method and structure disclosed in CN101441905A, the purpose of jumpering is achieved by changing the internal circuit layout of the flexible ribbon cable. Specifically, a conductor layer and an insulating layer are directly fabricated on the extension of the flexible main ribbon cable, so that the contacts of the conductors covered in the main ribbon cable are located on the extension. Through the relative design between the coating pattern of the conductor layer and the multiple conductor contacts of the main ribbon cable, the multiple conductors of the flexible ribbon cable are electrically connected and the connection positions are staggered. The spacing between the parallel adjacent metal conductor contacts of the flexible ribbon cable is changed by the conductor layer fabricated on the extension to change the spacing of the final output terminal contacts, so as to connect electrical connectors with different terminal spacings and achieve the effect of jumpering.

[0005] The inventors believe that the existing traditional technology of leading out a pad from a single ribbon cable that requires jumpers is inconvenient and prone to errors. Furthermore, the jumper method in the published documents results in a thicker flexible ribbon cable. Neither of these methods is suitable for application in electrical connection systems in fields such as new energy vehicle battery modules and energy storage battery modules.

[0006] In the battery industry, technicians typically cut, bend, and solder the cables from the FFC (Fuel-like Wire Condensate) to the external electrical system. This can lead to the following problems:

[0007] 1. The cutting and bending of FFC is difficult. The FFC used in new energy battery modules is usually large in size and has many wiring, making it difficult to achieve automated production. Manual operation is inefficient and costly, and prone to errors, making it difficult to carry out stable large-scale production.

[0008] 2. After FFC is bent, the positions of each wire are not fixed, the product flatness is poor, the downstream assembly process cannot achieve automated production, manual operation is inefficient and costly, and is prone to operation errors, resulting in unstable product quality. Summary of the Invention

[0009] The purpose of this invention is to address the aforementioned problems by providing a structure for a flexible flat cable that can effectively reduce production costs and avoid assembly errors that are prone to occur when manually connecting wire harnesses, as well as a production process that enables the rapid production of this cable.

[0010] To achieve the above technical objectives, the following technical solution is provided:

[0011] In a first aspect, a flexible flat cable structure includes a main strand of flexible wires, solder pad areas connected to both sides of the main strand of flexible wires, a base film covering the entire structure formed by the main strand of flexible wires and the solder pad areas, and a surface cover film covering the base film, wherein the base film and the surface cover film have opening areas for accommodating wiring of the solder pad areas.

[0012] The main cable in this application is formed using the FFC (Flexible Flat Cable) standard process. The middle section of the cable is thinner and serves as an electrical connection; the two side sections are thicker and can be processed into pads for connecting to external electrical systems. Based on the above, solder pad areas are formed on the two side cables, and open areas are formed on the two side cables.

[0013] In one feasible implementation, the main cable bus has an opening at which a connecting wire connects to the pad area; it also has a through hole for breaking a single cable in the main cable bus.

[0014] In one feasible approach, the connecting wire is positioned close to the main cable strip and is secured to the main cable strip by applying an adhesive layer or attaching a layer of tape to the connecting wire.

[0015] In feasible embodiments, the base film and the surface cover film are made of one or more insulating materials selected from PI, PET, and PEN.

[0016] In feasible implementations, the individual strands in the main cable bundle are copper wire, aluminum wire, or a combination of copper and aluminum wire.

[0017] In feasible implementations, the connecting wire is an aluminum or copper wire with a diameter of 0.05mm to 0.5mm.

[0018] The second aspect is a manufacturing process for a flexible flat cable, which produces any of the flexible flat cables mentioned in the first aspect.

[0019] Among the feasible approaches,

[0020] Step 1 involves performing a windowing process on the flexible flat cable obtained through standard procedures to obtain a pre-treated cable. The windowing process includes removing the surface cover film and base film on the solder pad area to form an opening area; and removing the surface cover film and base film on the main busbar to form an opening.

[0021] Step 2: Cut the pre-processed cable from Step 1 to obtain a rough-processed cable; the cutting process involves shaping the pad area to make the shape of the pad area meet the actual requirements; and punching holes in the main cable of the flexible wire to form through holes so that multiple individual cables can be cut off at appropriate positions.

[0022] Step 3: Connect the rough-machined cable from Step 2 with jumpers to obtain the fine-machined cable; wherein the jumper connection is to connect a portion of the open area to the opening via a connecting wire;

[0023] Step 4: Perform surface treatment on the precision-processed cable from Step 3 to obtain the finished cable. The surface treatment involves applying glue or tape to the connecting wires to fix them onto the main cable busbar.

[0024] In an implementable manner, step 3 includes a wire selection step prior to the jumper connection, in which a connecting wire with a diameter matching the standard for overload fusing current is selected.

[0025] In an feasible implementation, the jumper connection in step 3 is secured using ultrasonic bonding. This securing method uses wire bonding jumpers to establish electrical connections between the windowed circuits.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. This FFC does not require slitting and bending of each cable. All processes can be automated using mature industrial solutions, resulting in high production efficiency, low cost, and stable quality.

[0028] 2. This FFC structure has no cabling or bending, resulting in excellent product flatness. Downstream assembly processes can be automated, leading to high production efficiency, low cost, and stable quality.

[0029] 3. Both sides of the PADs on this FFC can be directly soldered to external electrical systems. Downstream customers do not need to consider the orientation of the FFC during assembly, resulting in high design freedom and low assembly costs. Attached Figure Description

[0030] 1. Main cable strip, 2. Pad area, 3. Base film, 4. Surface cover film, 5. Opening area, 6. Opening, 7. Connecting line, 8. Through hole.

[0031] Figure 1 This is a front view of the overall structure of this embodiment.

[0032] Figure 2 for Figure 1 Enlarged view of point B in the middle;

[0033] Figure 3 A front-facing, downward-facing side view of the main cable conveyor direction;

[0034] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0035] Figure 5 A front view of the overall structure of a flexible flat cable obtained using standard processes;

[0036] Figure 6 This is a reverse side diagram of a flexible flat cable obtained using standard processes.

[0037] Figure 7 for Figure 5 Enlarged view of point C in the middle; Detailed Implementation

[0038] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] like Figure 1 , Figure 2 , Figure 3 and Figure 4 The first embodiment shown describes the structure of a flexible flat cable, which includes a main cable strip 1, solder pad areas 2 connected to both sides of the main cable strip 1, a base film 3 covering the entire structure formed by the main cable strip 1 and the solder pad areas 2, and a surface cover film 4 covering the base film 3. The base film 3 and the surface cover film 4 have opening areas 5 for accommodating wiring in the solder pad areas 2.

[0040] In this embodiment, the pad area 2 is C-shaped, with one end integrally formed with the main cable bus 1 and the other end being a free end used for electrical connection. One opening area 5 is located at the free end of the C-shaped pad area 2, meaning that both sides of the free end are completely outside the surface cover film 4 and the base film 3; the other opening area 5 is located at the connection point with the main cable bus 1, meaning that the surface cover film 4 and the base film 3 are removed from the pad area 2, exposing the pad area 2 outside the surface cover film 4 and the base film 3.

[0041] In this embodiment, the main cable bus 1 has an opening 6 located on one side of the main cable bus 1. The opening 6 is connected to an opening area 5 that is connected to a pad area 2 by a connecting line 7. That is, the opening 6 is connected to the exposed pad area 2 at the connection point with the main cable bus 1 by the connecting line 7. It also has a through hole 8, which is used to break a single cable in the main cable bus 1.

[0042] In this embodiment, the connecting wire 7 is disposed close to the main cable strip 1, and is fixed to the main cable strip 1 by applying an adhesive layer or sticking an adhesive tape layer to the connecting wire 7. The adhesive layer or adhesive tape layer can protect the connecting wire 7 and prevent it from breaking or failing under external force. In this embodiment, an adhesive layer is preferred.

[0043] The base film 3 and the surface cover film 4 are made of one or more insulating materials selected from PI, PET, and PEN. In this embodiment, the base film 3 is preferably a PI insulating film, and the surface cover film 4 is preferably a PI insulating film; or the base film 3 is preferably a PET insulating film, and the surface cover film 4 is preferably a PET insulating film; or the base film 3 is preferably a PEN insulating film, and the surface cover film 4 is preferably a PEN insulating film.

[0044] The individual wires in the aforementioned main flexible wire busbar 1 are copper wires, aluminum wires, or conductive wires composed of a combination of copper and aluminum wires. In this embodiment, the individual wires are preferably aluminum wires.

[0045] The connecting wire 7 mentioned above is an aluminum or copper wire with a diameter of 0.05mm to 0.5mm. In this embodiment, the connecting wire is preferably an aluminum wire, and its diameter is selected according to different overload breaking current standards to realize the overload protection function of the electrical system.

[0046] In this embodiment, the FFC structure connects the Pad section to the external electrical system. After collecting relevant electrical data, it transmits the data to the internal wiring harness of the FFC via jumpers, and then outputs the data through the internal wiring harness port. This structure is very suitable for use in the signal acquisition system of power batteries and energy storage batteries in new energy vehicles.

[0047] Example 2: The manufacturing process of the flexible flat cable in Example 1 is as follows:

[0048] Step 1 involves performing a windowing process on the flexible flat cable obtained through standard procedures to obtain a pre-treated cable. The windowing process involves removing the surface cover film 4 and base film 3 on the pad area 2 to form an opening area 5. Additionally, the surface cover film 4 and base film 3 on one side of the main cable busbar 1 are removed to form an opening 6.

[0049] In step 1, the flexible flat cable produced using existing technology has a thinner middle section for electrical connection and thicker side sections for forming pads that connect to external electrical systems. The width of the middle section is adjusted according to actual needs; the thicker side sections form the pad forming area, and the conductor wire width is designed according to the actual pad size to create the visual effect of thickness.

[0050] In step 1, the opening area 5 includes a square area that is evenly distributed on both sides of the pad area 2; it also includes a circular hole area that is evenly distributed on the front side of the pad area 2, close to the square area on the front side of the pad area 2.

[0051] In step 1, opening 6 is a circular hole area. This area is evenly distributed on the front side of the pad area 2. It is located at the designated position of the ribbon cable that needs to be connected. The surface cover film 4 and base film 3 of the ribbon cable are removed to form opening 6.

[0052] The pre-treated cable after completing the above-mentioned opening area 5 is as follows: Figure 5 , Figure 6 and Figure 7 As shown.

[0053] Step 2: Cut the pre-processed cable from Step 1 to obtain a rough-processed cable; the cutting process involves shaping the pad area 2 to make the shape of the pad area 2 meet the actual requirements; and drilling holes in the main cable 1 to form through holes 8 so that multiple individual cables can be cut off at appropriate positions.

[0054] In this application, the pad area 2 is trimmed to remove unwanted areas to form the product shape; the shaped pad area 2 is "C"-shaped, with one end integrally formed with the main cable bus 1 and the other end being a free end for electrical connection. The pad area is exposed on both the top and bottom, allowing for top or bottom assembly with external electrical systems without considering orientation.

[0055] Step 3: Connect the rough-machined cable from Step 2 with jumpers to obtain the fine-machined cable; wherein the jumper connection is to connect the opening area 5 to the opening 7 through the connecting wire 7.

[0056] Step 3, prior to the jumper connection, includes a wire selection step where a connecting wire 7 with a diameter matching the overload fusing current standard is selected. The diameter of the connecting wire 7 is determined with reference to the overload fusing current standard.

[0057] The jumper connection in step 3 is fixed using ultrasonic pressure welding. The welding points are in the circular hole area and opening 6.

[0058] Step 4: Perform surface treatment on the precision-processed cable from Step 3 to obtain the finished cable. The surface treatment involves applying glue to the connecting wire 7 and fixing it to the main cable busbar 1.

[0059] The above embodiments, which describe the specific features of the present invention, are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above description of the invention shall fall within the scope of protection of the present invention.

Claims

1. A structure of a flexible flat cable comprising a soft wire main row (1), characterized in that, The soft wire main row (1) is connected with the solder pad area (2) on both sides, the whole formed by the soft wire main row (1) and the solder pad area (2) is covered with the base film (3), and the surface covering film (4) is covered on the base film (3), and the base film (3) and the surface covering film (4) have opening areas (5) for matching the wire connection of the solder pad area (2) and for electrical connection; The shape of the solder pad area (2) is "C" type, one end of which is integrally formed with the soft wire main row (1), and the other end is a free end for electrical connection; The base film (3) and the surface covering film (4) are made of one or more insulating materials of PI, PET, and PEN; The opening area (5) includes a square area at the free end of the "C" type solder pad area (2), which is uniformly distributed on the front and back of the solder pad area (2); it also includes a circular hole area at the connection of the soft wire main row (1), which is uniformly distributed on the front of the solder pad area (2) and close to the square area on the front of the solder pad area (2); The soft wire main row (1) has an opening (6) on the front of the soft wire main row (1), the opening (6) has a connecting wire (7) connected with the circular hole area of the opening area (5) of the solder pad area (2); it also has a through hole (8) for breaking a single row of wires in the soft wire main row (1); The connecting wire (7) is closely arranged on the soft wire main row (1), and the connecting wire (7) is fixed on the soft wire main row (1) by applying a layer of glue or pasting a layer of adhesive tape on the connecting wire (7).

2. The structure of the flexible flat cable according to claim 1, characterized by, The single row of wires in the soft wire main row (1) is a copper wire, or an aluminum wire, or a conductive wire composed of copper wire and aluminum wire.

3. The structure of the flexible flat cable according to claim 1, characterized by, The connecting wire (7) is an aluminum wire or a copper wire with a diameter of 0.05mm~0.5mm.

4. A production process of a flexible flat cable characterized by, The production process produces any one of the flexible flat cables in claims 1 to 3.

5. The production process of the flexible flat cable according to claim 4, characterized in that, Step 1: the flexible flat cable obtained by a standard process is subjected to windowing treatment to obtain a pretreated cable; wherein the windowing treatment is to remove the surface covering film (4) and the base film (3) on the solder pad area (2) to form the opening area (5); and the surface covering film (4) and the base film (3) on the soft wire main row (1) are also removed to form the opening (6); Step 2: the pretreated cable in step 1 is subjected to cutting treatment to obtain a rough processed cable; wherein the cutting treatment is to reshape the solder pad area (2) so that the shape of the solder pad area (2) meets the actual needs; and the soft wire main row (1) is punched to form the through hole (8) so that multiple single rows of wires are cut off at appropriate positions; Step 3: the rough processed cable in step 2 is subjected to jumper connection to obtain a finished cable; wherein the jumper connection is to connect part of the opening area (5) with the opening (6) through the connecting wire (7). Step 4: Surface treatment is performed on the finished cable obtained in Step 3, wherein the surface treatment is fixing the connecting wire (7) on the main cord (1) by applying glue or sticking adhesive tape on the connecting wire (7).

6. The production process of a flexible flat cable according to claim 5, wherein Step 3: The jumper connection further has a wire selection step before the jumper connection, in which the connecting wire (7) with a diameter matching the overload fuse breaking current is selected according to the standard of the overload fuse breaking current.

7. The production process of a flexible flat cable according to claim 6, wherein The jumper connection in Step 3 is fixed by ultrasonic pressure welding.

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