Aluminum-based FFC cable connection structure

Abstract

The utility model discloses an aluminum base FFC line row connecting structure, including FFC line row, pressure welding terminal and connector shell, FFC line row includes insulating layer and many flat conductors, and flat conductor has the conductive connecting part of the exposed connection mouth formed in insulating layer, and pressure welding terminal sets up the multiple pressure welding thorn for the puncture FFC line row insulating layer on the pressure welding part, and multiple pressure welding thorn rivet pressure fixed on the conductive connecting part on FFC line row, and the FFC line row of this technical scheme adopts the pressure welding process and realizes the mechanical bite fixed between pressure welding terminal and flat conductor, and the complex link such as medium processing, temperature control of welding is saved, and the process cost and operation difficulty are reduced significantly, and the pressure welding thorn punctures insulating layer through mechanical force and directly forms physical bite with the pressure welding of conductive connecting part, and the connecting strength is much higher than the adhesive force of soldering tin, and it is not easy to come loose, and this multi-point bite structure can disperse vibration impact force, and is suitable for the high frequency vibration working condition of automobile battery.

Description

Technical Field

[0001] This utility model relates to the field of FFC busbar technology, specifically to an aluminum-based FFC busbar connection structure. Background Technology

[0002] With the continuous development of new energy technologies, the core power battery system (Pack) and battery management system (BMS) have placed higher demands on the connection technology of internal wiring harnesses: reliable signal acquisition and transmission between a large number of cells must be achieved within a limited space, while coping with complex operating conditions such as vibration, high temperature, and electromagnetic interference. Against this backdrop, FFC, due to its unique physical and electrical characteristics, has become an ideal data transmission solution for new energy battery systems.

[0003] FFC (Flexible Flat Cable) is a new type of data cable made of insulating material and extremely thin tinned flat copper wire, pressed together by automated production lines. Existing FFC busbars allow for arbitrary selection of the number and spacing of conductors, making wiring more convenient, significantly reducing the size of electronic products, lowering production costs, and improving production efficiency. They are ideally suited for data transmission cables between moving parts and motherboards, between PCBs, and in miniaturized electrical devices. This type of FFC busbar uses FFC connectors to connect electrical devices. The conductive terminals of the FFC connectors contact the flat conductors of the FFC busbar and are fixed together by soldering, thus achieving circuit continuity. However, this soldering method requires applying solder paste, flux, and other external media to the flat conductors of the FFC, resulting in higher costs and a more complex soldering process. Furthermore, FFC is susceptible to thermal stress and heat damage, increasing production costs. Utility Model Content

[0004] Therefore, the technical problem to be solved by this utility model is to overcome the problems of the existing technology where the conductive terminals of the FFC busbar and the connector are fixedly connected by soldering, which is complicated by the soldering process, has high setup cost, and is susceptible to thermal stress and thermal damage.

[0005] To solve the above problems, this utility model provides an aluminum-based FFC busbar connection structure, including an FFC busbar, crimp terminals and a connector housing. The FFC busbar includes an insulating layer and multiple flat conductors. The multiple flat conductors are spaced apart and embedded in the insulating layer. The insulating layer has connection ports corresponding to the multiple flat conductors. The flat conductors have conductive connection portions exposed at the connection ports.

[0006] The crimp terminal includes a crimp portion stacked with the conductive connection portion of the FFC busbar, and a mounting portion extending out of the FFC busbar. The crimp portion is provided with a plurality of crimping protrusions for crimping and fixing to the conductive connection portion after piercing the insulation layer. The plurality of crimping protrusions are spaced apart along the length direction of the conductive connection portion. The connector housing is provided with at least one terminal cavity adapted to the crimp terminal. After the crimp terminal is crimped with the FFC busbar, it is inserted into the terminal cavity through the mounting portion and assembled to form an FFC connector that is connected to the FFC busbar circuit.

[0007] As a preferred embodiment, the crimping portion of the crimping terminal is a U-shaped wrapping structure that extends in the same direction as the conductive connection portion.

[0008] As a preferred embodiment, the multiple crimping protrusions are V-shaped spike structures formed alternately on both sides of the crimping portion, and are crimped with the conductive connection portion to form a crimping interlocking band extending along the length direction of the conductive connection portion.

[0009] As a preferred embodiment, the crimped joint between the crimped portion and the FFC busbar is coated with a protective adhesive contained in the joint.

[0010] As a preferred embodiment, the insulating layer includes two insulating films that press multiple flat conductors together, and an adhesive layer coated between the insulating films and the flat conductors, wherein the multiple flat conductors are flat aluminum wires arranged in the adhesive-coated area between the two insulating films.

[0011] As a preferred embodiment, multiple sampling plates are provided on both sides of the FFC busbar. The sampling plates are electrically connected to the flat conductor and extend out of the outside of the FFC busbar for connecting the battery cell module.

[0012] As a preferred embodiment, the sampling sheet includes multiple sets of welding units distributed at intervals corresponding to multiple flat conductors. The sampling sheet is welded to one of the flat conductors through one set of welding units, and the insulating layer has corresponding contact windows for connecting the welding units to the flat conductors.

[0013] As a preferred embodiment, solder is applied between the welding unit and the corresponding flat conductor. The welding unit includes a plurality of welding holes spaced apart along the extension direction of the flat conductor on the sampling sheet, so that the solder passes through the plurality of welding holes and combines with the sampling sheet to form a plurality of welding anchor points.

[0014] As a preferred embodiment, the sampling sheet is an aluminum sheet structure with a collection end extending out of the FFC busbar for connecting to the battery cell module. A temperature sensing element for collecting temperature information of the battery cell module is attached to the collection end.

[0015] As a preferred embodiment, the sampling sheet can also be laser-welded to the flat conductor.

[0016] As a preferred embodiment, the FFC busbar is connected to a PCB board, and the PCB board is provided with multiple PCB pads spaced apart. The flat conductor of the FFC busbar is fixed to the PCB pads on the PCB board by ultrasonic welding.

[0017] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:

[0018] 1. In the aluminum-based FFC busbar connection structure provided by this utility model, the crimp terminal is provided with multiple crimping protrusions on the crimping part for piercing the insulation layer of the FFC busbar, and the multiple crimping protrusions are riveted and fixed on the FFC busbar, and maintain close contact with the conductive connection part of the flat conductor exposed at the connection port. After crimping, the crimp terminal can be directly installed into the connector housing to form an integral FFC connector, thereby realizing the installation connection between the FFC connector and the FFC busbar. The advantage of this design is that the crimping terminal and the FFC busbar only need to go through a three-step standardized process of crimping terminal alignment, crimping protrusion piercing the insulation layer, and mechanical crimping fixation. This process eliminates the complex steps of welding, such as medium treatment and temperature control, significantly reducing process costs and operational difficulty. The crimping protrusions pierce the insulation layer by mechanical force and directly crimp to the conductive connection to form a physical interlock. The connection strength is much higher than the bonding strength of solder, making it less prone to loosening. Multiple crimping protrusions are arranged at intervals along the length of the conductive connection to form multi-point interlocking contact. This multi-point interlocking structure can disperse vibration and impact forces, adapting to the high-frequency vibration conditions of automotive batteries. The crimping process used in this FFC busbar solution is suitable for high-speed automated production equipment and can be easily integrated into automated assembly lines. It is suitable for the mass production needs of FFC products, enhancing the market competitiveness of the products.

[0019] 2. In the aluminum-based FFC busbar connection structure provided by this utility model, the crimping part adopts a U-shaped wrapping structure design, which can form a wrapping limit on the conductive connection part from both sides and bottom, ensuring the long-term stability of the relative position of the conductor and the terminal after crimping, and avoiding connection loosening caused by vibration. According to the multiple crimping protrusions, the V-shaped spike structure is formed by staggered formation on both sides of the crimping part. The V-shaped spike structure has a small tip area and high pressure, which can more easily pierce the insulation layer of FFC, reduce the power requirements of the crimping equipment, and the multiple crimping protrusions form non-overlapping two-sided interlocking points on the conductive connection part, avoiding the conductor from being subjected to double compression at the same position, dispersing the compression stress, reducing the risk of breakage, significantly improving the vibration and impact resistance, and improving the reliability of the connection between the crimping terminal and the FFC flat conductor.

[0020] 3. In the aluminum-based FFC busbar connection structure provided by this utility model, the sampling sheet can be flexibly matched according to the number of battery cells, supporting multi-channel synchronous sampling to meet the monitoring needs of large-scale battery cell modules. Each sampling sheet is equipped with multiple welding units at intervals along multiple flat conductors, and each group of welding units is connected to a flat conductor to form an independent signal transmission path. This design enables multi-channel independent sampling of the battery cell module, avoids signal crosstalk, and improves sampling accuracy.

[0021] 4. In the aluminum-based FFC busbar connection structure provided by this utility model, the sampling sheet and the flat conductor are connected by laser welding or hot-press welding. When using hot-press welding, solder is usually applied between the sampling sheet and the flat conductor, and multiple welding holes are spaced apart on the sampling sheet. In this structure, the sampling sheet and the flat conductor are stacked and attached together during the welding process, which allows the solder to pass through the welding holes and form a strong weld point, completely filling the gaps between the layers and eliminating air residue. The solder filling the welding holes forms a three-dimensional contact anchoring structure with the sampling sheet and the flat conductor. This structure can effectively disperse vibration stress and thermal stress, avoid stress concentration at the welding edge leading to cracking, increase the contact area, strengthen the mechanical connection strength, improve vibration resistance, and ensure connection stability. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the stacked structure of the FFC busbar provided by this utility model;

[0024] Figure 2 A schematic diagram of the split structure of the aluminum-based FFC busbar connection structure provided by this utility model;

[0025] Figure 3 This is a schematic diagram of the crimping structure of the FFC busbar and crimping terminal of this utility model;

[0026] Figure 4 This is a partially enlarged structural diagram of the FFC busbar of this utility model, with the sampling sheet specifically shown.

[0027] 1. FFC wire; 11. Flat conductor; 12. Insulation layer; 13. Conductive connection part; 2. Crimping terminal; 21. Crimping part; 22. Crimping protrusion; 23. Mounting part; 3. Connector housing; 4. Sampling piece; 41. Acquisition end; 5. Solder hole; 6. Contact window; 7. Temperature sensing element; 100. FFC connector. Detailed Implementation

[0028] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0029] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0032] Example

[0033] This embodiment provides, as follows: Figure 1-4The diagram illustrates an aluminum-based FFC busbar connection structure, comprising an FFC busbar 1, crimp terminals 2, and a connector housing 3. The FFC busbar 1 includes an insulating layer 12 and multiple flat conductors 11, which are spaced apart and embedded within the insulating layer 12. The insulating layer 12 has connection ports corresponding to the multiple flat conductors 11, and each flat conductor 11 has a conductive connection portion 13 exposed at the connection port. The crimp terminal 2 includes a crimp terminal that is stacked with the conductive connection portion 13 of the FFC busbar 1. The connector housing 3 has a crimping part 21 and a mounting part 23 extending out of the FFC busbar 1. The crimping part 21 is provided with a plurality of crimping protrusions 22 for crimping and fixing to the conductive connection part 13 after piercing the insulating layer 12. The plurality of crimping protrusions 22 are spaced apart along the length direction of the conductive connection part 13. The connector housing 3 is provided with at least one terminal cavity adapted to the crimping terminal 2. After the crimping terminal 2 is crimped with the FFC busbar 1, it is inserted into the terminal cavity through the mounting part 23 and assembled to form an FFC connector 100 that is electrically connected to the FFC busbar 1.

[0034] In the above embodiment, the crimp terminal 2 is provided with multiple crimping protrusions 22 on the crimping part 21 for piercing the insulation layer 12 of the FFC busbar 1, and the multiple crimping protrusions 22 are riveted and fixed on the FFC busbar 1, and are in close contact with the conductive connection part 13 of the flat conductor 11 exposed at the connection port. Then, the crimp terminal 2 after crimping is directly installed into the connector housing 3 to form an integral FFC connector 100, thereby realizing the installation connection between the FFC connector 100 and the FFC busbar 1. The advantage of this design is that the crimp terminal 2 and the FFC busbar 1 only need to be aligned by the crimp terminal 2, the crimping protrusions 22 piercing the insulation layer 12, and mechanically crimped and fixed during the crimping process. The three-step standardized process eliminates complex steps such as welding medium treatment and temperature control, significantly reducing process costs and operational difficulty. The crimping protrusions 22 pierce the insulation layer 12 by mechanical force and directly crimp with the conductive connection part 13 to form a physical interlock. The connection strength is much higher than the bonding force of solder and is not easy to loosen. Multiple crimping protrusions 22 are arranged at intervals along the length of the conductive connection part 13 to form a multi-point interlocking contact. This multi-point interlocking structure can disperse vibration and impact forces and is suitable for the high-frequency vibration conditions of automotive batteries. The crimping process adopted by this FFC solution is suitable for high-speed automated production equipment and can be easily integrated into automated assembly lines. It is suitable for the mass production needs of FFC products and enhances the market competitiveness of the products.

[0035] In a further preferred embodiment, the crimping portion 21 of the crimping terminal 2 is a U-shaped wrapping structure extending in the same direction as the conductive connection portion 13. This U-shaped wrapping structure design of the crimping portion 21 can form a wrapping restraint on the conductive connection portion 13 from both sides and the bottom, ensuring that the conductor and the terminal maintain stable contact after crimping and avoiding loosening of the connection due to vibration. (Refer to...) Figure 3 The multiple crimping protrusions 22 are staggered V-shaped spike structures formed on both sides of the crimping portion 21, and are crimped with the conductive connection portion 13 to form a crimping engagement band extending along the length direction of the conductive connection portion 13. The advantage of this design is that the V-shaped spike structure has a small tip area and high pressure, which can more easily pierce the insulation layer 12 of FFC, reduce the power requirements of the crimping equipment, and the multiple crimping protrusions 22 are crimped on the conductive connection portion 13 to form non-overlapping engagement points on both sides, avoiding the conductor being subjected to double compression at the same position, dispersing the compression stress, reducing the risk of breakage, significantly improving the vibration and impact resistance, and improving the reliability of the connection between the crimping terminal 2 and the FFC flat conductor 11.

[0036] In this embodiment, the insulating layer 12 includes two insulating films that press multiple flat conductors 11 together, and an adhesive layer coated between the insulating films and the flat conductors 11. The multiple flat conductors 11 are flat aluminum wires arranged in the adhesive-coated area between the two insulating films. The connection port is an open window structure opened on one of the insulating films. The crimping part 21 and the crimping connection of the FFC busbar 1 are coated with protective adhesive contained in the connection port. The protective adhesive covers the exposed conductive connection part 13 and the crimping part 21, thereby forming a dense sealing layer that completely isolates the crimping point from the external environment, playing the role of sealing, isolation and insulation protection.

[0037] In this embodiment, the FFC busbar is responsible for circuit conduction and signal sampling of the battery cell module. For details, please refer to... Figure 1-4 As shown, multiple sampling plates 4 are arranged on both sides of the FFC busbar 1. The sampling plates 4 are electrically connected to the flat conductor 11 and extend outward from the FFC busbar 1 for connecting to the battery cell module. The sampling plates 4 are selected as aluminum sheet structures according to the material of the flat conductor 11. They have a collection end 41 extending outward from the FFC busbar 1 for connecting to the battery cell module. Temperature sensing elements 7 are attached to the collection end 41 to collect the temperature information of the battery cell module. The temperature sensing element 7 is preferably a temperature sensor. The extension length and spacing of the sampling plates 4 can be preset according to the sampling point position of the battery cell module. During installation, the FFC busbar 1 is simply attached to the battery cell module so that the collection end 41 of the sampling plate 4 can be directly aligned with the sampling point of the battery cell module, thereby realizing the connection between the FFC busbar and the battery cell module. The sampling piece 4 of this FFC busbar can be flexibly matched according to the number of cells, supports multi-channel synchronous sampling, and meets the monitoring needs of large-scale cell modules. Each sampling piece 4 is welded to a flat conductor on the FFC busbar. Specifically, the sampling piece and the flat conductor are preferably connected by laser welding, but hot-press welding can also be used.

[0038] To reliably achieve the welding and fixing between the sampling piece and the flat conductor, the hot-press welding method between the sampling piece and the FFC busbar is described in detail below. Each sampling piece 4 corresponds to multiple flat conductors 11 and is provided with multiple welding units at intervals. The sampling piece 4 is welded to one of the flat conductors 11 through one of the welding units. This design forms an independent signal transmission path by connecting one sampling piece 4 to the corresponding flat conductor 11, thereby realizing multi-channel independent sampling of the cell module, avoiding signal crosstalk, and improving sampling accuracy. Specifically, the insulating layer 12 has a corresponding contact window 6 for connecting the welding unit and the flat conductor 11. Solder is applied between the welding unit and the corresponding flat conductor 11. The solder is preferably tin. The welding unit includes a plurality of welding holes 5 spaced apart along the extension direction of the flat conductor 11 on the sampling piece 4. Specifically, the sampling piece 4 is welded to the corresponding flat conductor 11 at the contact window position using the HOTBAR process. The HOTBAR process uses a precision hot press head to locally heat and pressurize the pads, which can achieve ultra-fine pitch welding. It is suitable for high-density interconnection between the sampling piece 4 and FFC, and is well-suited for FFC products with stringent requirements for space, weight and flexibility, significantly improving the durability and manufacturing efficiency of the product. In this structural setup, during the welding process, the sampling piece 4 and the flat conductor 11 are arranged in an upper and lower stacked fit. This allows the solder to pass through multiple welding holes 5 and combine with the sampling piece 4 to form multiple welding anchor points, completely filling the interlayer gaps and eliminating residual air. The solder filling the welding holes forms a three-dimensional contact anchoring structure with the sampling piece and the flat conductor. This structure can effectively disperse vibration stress and thermal stress, avoid stress concentration at the welding edge leading to cracking, increase the contact area, strengthen the mechanical connection strength, improve vibration resistance, and ensure connection stability.

[0039] In this embodiment, the FFC busbar 1 can not only be connected to electrical components via the FFC connector 100, but also be directly fixed to a PCB board via ultrasonic welding. The PCB board houses the electrical components, specifically configured as follows: the PCB board has multiple PCB pads spaced apart; the FFC busbar 1 includes multiple FFC pads formed by multiple flat conductors 11 exposed above the insulating layer. After the multiple FFC pads are bonded to the multiple PCB pads, they are fixedly connected via ultrasonic welding. This design achieves electrical connection between the FFC busbar and the PCB board. The core of this ultrasonic welding method between the FFC busbar and the PCB board is to generate localized frictional heat at the metal contact surfaces of the FFC pads and PCB pads through high-frequency mechanical vibration, achieving a solid-state connection between the metals. This eliminates the need for high-temperature solder and flux, overcoming the problems of heat damage, environmental impact, and reliability associated with traditional soldering. It is particularly suitable for heat-sensitive FFC flexible connection scenarios. Based on the above configuration of the FFC busbar and PCB board, the terminals of the FFC connector can also be fixed to the flat conductors of the FFC busbar via ultrasonic welding.

[0040] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. An aluminum-based FFC busbar connection structure, comprising an FFC busbar (1), crimp terminals (2), and a connector housing (3), characterized in that: The FFC busbar (1) includes an insulating layer (12) and multiple flat conductors (11). The multiple flat conductors (11) are spaced apart and embedded in the insulating layer (12). The insulating layer (12) has connection ports for each of the multiple flat conductors (11). The flat conductors (11) have conductive connection portions (13) exposed at the connection ports. The crimp terminal (2) includes a crimp portion (21) stacked with the conductive connection portion (13) of the FFC busbar (1) and a mounting portion (23) extending out of the FFC busbar (1). The crimp portion (21) is provided with a plurality of crimping protrusions (22) for crimping and fixing to the conductive connection portion (13) after piercing the insulating layer (12). The plurality of crimping protrusions (22) are spaced apart along the length direction of the conductive connection portion (13). The connector housing (3) is provided with at least one terminal cavity adapted to the crimp terminal (2). After the crimp terminal (2) is crimped with the FFC busbar (1), it is inserted into the terminal cavity through the mounting portion (23) and assembled to form an FFC connector (100) that is electrically connected to the FFC busbar (1).

2. The aluminum-based FFC busbar connection structure according to claim 1, characterized in that: The crimping portion (21) of the crimping terminal (2) is a U-shaped wrapping structure that extends in the same direction as the conductive connection portion (13).

3. The aluminum-based FFC busbar connection structure according to claim 2, characterized in that: Multiple crimping protrusions (22) are V-shaped spike structures formed alternately on both sides of the crimping part (21), and are crimped with the conductive connection part (13) to form a crimping interlocking band extending along the length direction of the conductive connection part (13). The crimping connection between the crimping part (21) and the FFC busbar (1) is coated with protective adhesive contained in the connection port.

4. The aluminum-based FFC busbar connection structure according to claim 1, characterized in that: The insulating layer (12) includes two insulating films that press against each other multiple flat conductors (11), and an adhesive layer coated between the insulating film and the flat conductors (11). The multiple flat conductors (11) are flat aluminum wires arranged in the adhesive area between the two insulating films.

5. The aluminum-based FFC busbar connection structure according to any one of claims 1-4, characterized in that: Multiple sampling plates (4) are provided on both sides of the FFC busbar (1). The sampling plates (4) are electrically connected to the flat conductor (11) and extend out of the outside of the FFC busbar (1) for connecting the battery cell module.

6. The aluminum-based FFC busbar connection structure according to claim 5, characterized in that: The sampling piece (4) includes multiple sets of welding units distributed at intervals corresponding to multiple flat conductors (11). The sampling piece (4) is welded to one of the flat conductors (11) through one set of welding units. The insulating layer (12) is provided with a contact window (6) for connecting the welding unit and the flat conductor (11).

7. The aluminum-based FFC busbar connection structure according to claim 6, characterized in that: Solder is applied between the welding unit and the corresponding flat conductor (11). The welding unit includes a plurality of welding holes (5) spaced apart along the extension direction of the flat conductor (11) on the sampling piece (4), so that the solder passes through the plurality of welding holes (5) and combines with the sampling piece (4) to form a plurality of welding anchor points.

8. The aluminum-based FFC busbar connection structure according to claim 6 or 7, characterized in that: The sampling sheet (4) is an aluminum sheet structure with a collection end (41) extending out of the outside of the FFC busbar (1) for connecting the battery cell module. Temperature information of the battery cell module is collected by attaching a temperature sensing element (7) to the collection end (41).

9. The aluminum-based FFC busbar connection structure according to claim 5, characterized in that: The sampling sheet is laser-welded to the flat conductor.

10. The aluminum-based FFC busbar connection structure according to claim 1, characterized in that: The FFC busbar (1) is connected to the PCB board, and the flat conductor of the FFC busbar (1) is fixed to the PCB pads on the PCB board by ultrasonic welding.

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