A Hollowing Processing Method for a Signal Sampling Component of a Power Battery Pack

Abstract

The present invention discloses a hollowing processing method for a signal sampling component of a power battery pack, including: product circuit design: replacing nickel sheet electrodes with copper foils and adding them to the circuit design; manufacturing a flexible printed circuit board by using a hollowing board manufacturing process, where the flexible printed circuit board includes two layers, namely a circuit layer and a protective film layer; making the circuit layer of the flexible printed circuit board face upward, assembling a lower cover film, an aluminum row, and the flexible printed circuit board on a carrier in a stacked structure order from bottom to top, and pre-pressing and fixing; pasting a cover film on the circuit layer of the flexible printed circuit board, and then performing lamination. Through the cover film lamination method, the connecting electrodes in the flexible printed circuit board are tightly bonded to the aluminum row; welding sensors and connectors; dispensing glue; laser welding, where the connecting electrodes and the aluminum row in the circuit are welded together by laser. This processing method can greatly reduce equipment investment, reduce the quality hidden dangers of nickel sheet electrode welding, and has high production efficiency through circuit design optimization and process optimization.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and particularly to a method for hollowing out and processing a signal sampling component of a power battery pack. Background Art

[0002] With the strong support and encouragement of national policies for new energy vehicles, the new energy vehicle track has become increasingly popular. The new energy battery pack is one of the core components of new energy vehicles, and the production processes, production efficiency, and costs of its various components have also become the core competitiveness of each company.

[0003] The processing technology of traditional new energy battery pack signal acquisition components is as follows:

[0004] Single-sided copper foil substrate → Exposure → Etching (conductors, fuses) → Laminating a cover film → Pressing the cover film → Laminating a reinforcement → Pressing the reinforcement → Die-cutting the outer shape → SMT (attaching nickel sheet electrodes, NTCs, connectors) → Attaching a nickel sheet electrode film → Pressing the nickel sheet electrode film → Dispensing glue → Pressing IBB (Integrated Bus Bar for Battery, usually called an integrated bus bar) → Dispensing glue → Laser welding.

[0005] The traditional process scheme has the following disadvantages:

[0006] 1) It is necessary to laminate and press the cover film multiple times, resulting in high material and processing costs and a long production cycle;

[0007] 2) SMT processing is required, involving equipment investment, low processing efficiency, and quality risks such as poor soldering of connectors and NTCs and delamination during furnace passing. Summary of the Invention

[0008] In view of the above-mentioned defects of the prior art, the purpose of the present invention is to provide a processing method for a signal acquisition component of a power battery pack to simplify the processing technology and improve the product quality.

[0009] To achieve the above purpose, the present invention provides a method for hollowing out and processing a signal sampling component of a power battery pack, which is characterized by including:

[0010] Step S1, product circuit design: replacing the connection electrodes with copper foil and adding them to the circuit;

[0011] Step S2, manufacturing a flexible circuit board using a hollowed-out board manufacturing process, the flexible circuit board including two layers, namely a circuit layer and a protective film layer;

[0012] Step S3, FPC assembly pre-pressing: making the circuit layer of the flexible circuit board face upward, assembling the lower cover film, aluminum row, and flexible circuit board in the stacking order from bottom to top on a carrier, and pre-pressing and fixing them; the lower cover film has been subjected to windowing treatment;

[0013] Step S4, Film Laminating: Apply an upper cover film on the surface of the circuit layer of the flexible printed circuit board; the upper cover film has been subjected to windowing treatment;

[0014] Step S5, Pressing: Through the pressing method of the upper and lower cover films, make the connection electrodes in the flexible printed circuit board between the upper and lower cover films tightly bonded to the aluminum busbar;

[0015] Step S6, Sensor Welding and Connector Welding;

[0016] Step S7, Glue Dispensing;

[0017] Step S8, Laser Welding: Weld the connection electrodes in the flexible printed circuit board and the aluminum busbar in the circuit together by laser.

[0018] Further, the step S2 includes: Select a single-sided copper-clad substrate, apply a protective film on the back of the single-sided copper-clad substrate; complete the circuit forming through the etching process; perform windowing on the protective film to expose the connection electrodes; punch out the shape of the flexible printed circuit board with a mold.

[0019] Further, the thickness of the single-sided copper-clad substrate is 20 - 50 microns.

[0020] Further, the protective film in the step S2 adopts a PI protective film.

[0021] Further, the upper cover film and the lower cover film are insulating cover films with a thickness of 60 - 150 microns.

[0022] Further, the sensor is a negative temperature coefficient temperature sensor; the welding method is spot welding or piercing and crimping method.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] 1) Replace the nickel sheet electrode with copper foil, reduce processes such as SMT and nickel sheet material processing, and reduce the investment in equipment such as SMT, SPI, and AOI; at the same time, reduce quality risks such as open soldering and false soldering of the nickel sheet electrode.

[0025] 2) Through the double protection of IBB pressing and laser welding, the strength requirement between the copper foil and the aluminum busbar is eliminated, and the electrical performance is better.

[0026] 3) The copper foil is thinner than the nickel sheet electrode, and the production efficiency of laser welding can be increased several times. Description of the Drawings

[0027] Figure 1 is an FPC example of a new energy battery pack signal acquisition component currently using a nickel sheet electrode;

[0028] Figure 2It is the process flow chart of the signal sampling component of the power battery pack of the present invention;

[0029] Figure 3 It is an example of the circuit design of the signal sampling component of the power battery pack of the present invention;

[0030] Figure 4 It is the stacking schematic diagram of the intermediate product after the single-sided copper-clad film covering step;

[0031] Figure 5 [[ID='12]]It is the top view of the intermediate product after the etching and protective film windowing steps;

[0032] Figure 6 It is the top view of the intermediate product after the circuit punching step;

[0033] Figure 7 It is an example of the design of the upper cover film;

[0034] Figure 8 It is an example of the design of the lower cover film;

[0035] Figure 9 It is the stacking schematic diagram of the intermediate product after the FPC assembly pre-pressing;

[0036] Figure 10 It is the top view of the intermediate product after the FPC assembly pre-pressing;

[0037] Figure 11 It is the stacking schematic diagram of the intermediate product after the film laminating step;

[0038] Figure 12 It is the top view of the intermediate product after the film laminating step;

[0039] Figure 13 It is the stacking schematic diagram of the intermediate product after the IBB bonding step;

[0040] Figure 14 It is the top view of the formed product after the laser welding. Detailed implementation manners

[0041] To further illustrate the embodiments, the present invention provides accompanying drawings. These accompanying drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used to explain the operating principle of the embodiments in conjunction with the relevant descriptions in the specification. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0042] Now, the present invention will be further described in conjunction with the accompanying drawings and specific implementation manners.

[0043] AsFigure 2 As shown, the present invention discloses a processing method for a signal sampling component of a power battery pack, including the following steps:

[0044] Step S1, product circuit design: Replace the nickel sheet electrode with copper foil and add it to the design of Circuit 1 to form a connection electrode 2. A sensor pad 3 is also provided in Circuit 1. This process has the following advantages compared with the traditional process: 1) Replacing the nickel sheet electrode with copper foil has better electrical and thermal conductivity; 2) The circuit processing can be formed in one step, saving processes such as SMT welding and nickel sheet electrode processing, and saving the investment in related equipment such as SMT, SPI, and AOI; at the same time, it avoids quality hazards such as virtual soldering and void soldering of nickel sheet electrode welding.

[0045] Step S2, fabricate a flexible printed circuit board (FPC) using the traditional hollow board manufacturing process.

[0046] This step specifically includes:

[0047] Select a common single-sided shiny copper substrate 4, and attach a protective film 5 to the back of the single-sided shiny copper substrate 4, as Figure 4 shown;

[0048] Complete the circuit forming through the etching process (applying dry film, exposure, development, etching, stripping); then open a window in the protective film 5 to expose the connection electrode 2; as Figure 5 shown;

[0049] Outer shape punching: Combine the product design to make a mold to punch out the outer shape of the flexible printed circuit board 6, as Figure 6 shown.

[0050] In this step, compared with the traditional hollow board manufacturing process, the process of attaching a cover film after circuit forming is reduced, and the outer shape is directly punched, which can save cover film materials and shorten the production cycle.

[0051] In specific applications, the thickness of the single-sided shiny copper substrate is 20 to 50 microns, and the typical thickness is 20 microns or 35 microns, which can be adjusted accordingly according to performance requirements and material selection.

[0052] Before performing Step S3, it is necessary to prepare an upper cover film 7 and a lower cover film 8 for laminating Circuit 1 and the aluminum row 9. Both the upper cover film 7 and the lower cover film 8 are designed with window openings according to the exposure requirements of the electrical test points and electrical contact points of Circuit 1 and the aluminum row 9. As Figure 7 and Figure 8 shown.

[0053] Specifically, the upper cover film 7 and the lower cover film 8 are insulating cover films, which are used to protect the circuit and enhance the structural strength of the entire signal sampling component. The thickness of the upper cover film 7 and the lower cover film 8 is generally 60 - 150 microns, and can be adjusted accordingly in combination with performance requirements and material selection.

[0054] Step S3, FPC assembly pre-pressing: Place the side of the protective film 5 of the flexible printed circuit board 6 facing downwards, and assemble the lower cover film 8, the aluminum row 9, and the flexible printed circuit board 6 on the carrier in the stacking order from bottom to top, and pre-press and fix them, as Figure 9 、 Figure 10 shown.

[0055] Step S4, film pasting: Paste an upper cover film 7 on the surface of the circuit 1 of the flexible printed circuit board 6 to protect the circuit. As Figure 11 and Figure 12 shown.

[0056] Step S5, IBB lamination. Through the lamination method of the upper and lower cover films, the connection electrodes 2 in the flexible printed circuit board 6 located between the upper and lower cover films are tightly bonded to the aluminum row 9. As Figure 13 shown.

[0057] Step S6, welding of the NTC temperature sensor and the connector 10. NTC is a negative temperature coefficient temperature sensor. The NTC temperature sensor generally adopts a water droplet type temperature sensor, and the welding method is spot welding or piercing crimping, etc.

[0058] Step S7, dispensing. Dispense and fix the welded NTC sensor and the connector to enhance the bonding force of the device. At the same time, the dispensing at the position of the NTC sensor has a certain heat conduction effect.

[0059] Step S8, laser welding: Weld the connection electrode 2 and the aluminum row 9 in the circuit together by laser. After completing the laser welding, the signal sampling component of the power battery pack has been formed. As Figure 14 shown.

[0060] Laser welding is to melt and connect two metals together by laser. In this process, copper foil is used to replace the nickel sheet electrode, and the thickness of the copper foil is about one-tenth of that of the nickel sheet electrode. The production efficiency of laser welding can be increased several times.

[0061] In the traditional process, nickel sheet electrodes with a thickness of about 0.3 mm are generally used, and the nickel sheet electrodes are connected to the aluminum row by laser welding. The reason is that the nickel sheet electrode and the aluminum row are two independent structures. To ensure the firm connection between the two, the nickel sheet electrode needs to have sufficient strength. Therefore, the traditional process has relatively high requirements for the thickness and strength of the nickel sheet electrode.

[0062] In this process flow, the IBB lamination process is adopted first: through the lamination method of the cover film, the copper foil and the aluminum row are tightly bonded together, and then the conduction between the copper foil and the aluminum row is solved through laser welding. The advantage of this process is that through the lamination of the cover film, the copper foil and the aluminum row are first combined into a whole, thus eliminating the strength requirements between the copper foil and the aluminum row. Therefore, a thinner copper foil can be used in material selection, and there are two-fold protections of the cover film and laser welding in terms of electrical performance, and the stability is more guaranteed.

[0063] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes can be made to the present invention in terms of form and details without departing from the spirit and scope of the present invention defined by the appended claims, and all of them are within the protection scope of the present invention.

Claims

1. A hollowing processing method for a signal sampling component of a power battery pack, characterized in that, Including: Step S1, product circuit design: Replace the connecting electrodes with copper foils and incorporate them into the circuit design. Step S2, fabricate a flexible printed circuit board (FPC) using the traditional process of making a stencil plate. The FPC includes a laminated circuit layer and a protective film layer. Step S3, pre-press for FPC assembly: Place the circuit layer of the FPC facing upwards, and then assemble the lower cover film, aluminum busbar, and FPC in a stacked order from bottom to top on a carrier and pre-press to fix them. The lower cover film has been subjected to windowing treatment. Step S4, film lamination: Apply an upper cover film on the surface of the circuit layer of the FPC. The upper cover film has been subjected to windowing treatment. Step S5, lamination: Through the lamination method of the upper and lower cover films, tightly bond the connecting electrodes in the FPC located between the upper and lower cover films to the aluminum busbar. Step S6, sensor soldering and connector soldering. Step S7, dispensing. Step S8, laser soldering: Use a laser to solder the connecting electrodes in the FPC and the aluminum busbar in the circuit together.

2. The hollowing processing method of the power battery pack signal sampling component according to claim 1, characterized in that, The said Step S2 includes: Select a single-sided shiny copper substrate and attach a protective film to the back of the single-sided shiny copper substrate. Complete circuit formation through an etching process. Window the protective film to expose the connecting electrodes. Use a die to punch out the shape of the FPC.

3. The hollowing processing method of the power battery pack signal sampling component according to claim 2, characterized in that The thickness of the single-sided shiny copper substrate in Step S2 is 20 - 50 microns.

4. The hollowing processing method of the power battery pack signal sampling component according to claim 2, wherein The protective film in Step S2 uses a PI protective film.

5. The hollowing processing method of the power battery pack signal sampling component according to claim 1, characterized in that, The upper cover film and the lower cover film are insulating cover films with a thickness of 60 - 150 microns.

6. The hollowing processing method of the power battery pack signal sampling component according to claim 1, characterized in that, The sensor is a negative temperature coefficient temperature sensor; the soldering method is spot welding or piercing and crimping method.

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