A high-voltage battery module insulation composite die-cutting method

Abstract

This invention discloses a composite die-cutting method for high-voltage battery module insulation components, comprising: unwinding a high-voltage substrate layer and a flexible functional layer separately; stacking the materials of each layer in a predetermined order and performing roll forming, followed by vacuum defoaming and constant-temperature curing to obtain a composite insulation strip; performing die-cutting processing on the composite insulation strip according to a graded die-cutting mode to obtain individual insulation components, the graded die-cutting mode including: first die-cutting 20% ​​to 30% of the strip thickness with a first pressure value, second die-cutting 50% to 70% of the strip thickness with a second pressure value, and final die-cutting with a third pressure value; continuously spraying cooling gas into the die-cutting area during the die-cutting process to perform an online cooling process; and collecting and discharging the die-cutting waste to obtain the individual insulation components. This invention uses a three-stage die-cutting method to gradually increase the cutting depth, reduce edge chipping of the high-voltage substrate layer and stringing of the flexible functional layer, and ensure the insulation and high-voltage resistance performance of the insulation component.

Description

Technical Field

[0001] This invention relates to the field of battery insulation component processing technology, and in particular to a composite die-cutting method for high-voltage battery module insulation components. Background Technology

[0002] In power battery / energy storage battery modules, insulating components are typically required between the cells and end plates, busbars, and liquid cooling plates. These insulating components are usually formed by a composite of a high-pressure resistant substrate layer and a flexible functional layer. The high-pressure resistant substrate can be made of materials such as FR-4 (epoxy glass fiber), mica composite board, or PEEK (polyetheretherketone), which are typically characterized by high hardness and brittleness. The flexible functional layer can include materials such as PET (polyethylene terephthalate) / PI (polyimide) film, adhesive layer, and release layer, and its overall material is relatively soft.

[0003] During processing, the composite insulating material typically needs to be die-cut to obtain insulating components that match the shapes and sizes of battery modules. Currently, a one-time die-cutting method is commonly used, where multi-layer composite insulating material is punched into insulating components in a single process. This method is highly prone to chipping of the brittle substrate layer, stringing of the soft functional layer, and burr height often exceeding 20μm. These defects significantly increase the risk of insulation breakdown, leading to product defects and limiting the functionality of the battery module. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a composite die-cutting method for high-voltage battery module insulation components, which has the advantage of effectively improving the die-cutting quality.

[0005] The objective of this invention is achieved through the following technical solution: According to embodiments of this disclosure, a method for composite die-cutting of high-voltage battery module insulation components is provided, comprising: The high-pressure-resistant substrate layer and the soft functional layer are unwound separately, and the alignment deviation between the layers is controlled to be less than a predetermined deviation threshold. After stacking and rolling the materials in a predetermined order, vacuum defoaming treatment is performed to eliminate interlayer bubbles, followed by constant temperature curing treatment to obtain composite insulation tape. The composite insulating tape is die-cut according to a graded die-cutting pattern to obtain individual insulating components. The graded die-cutting pattern includes: an initial die-cutting with a first pressure value as light pressure and a die-cutting depth controlled at 20% to 30% of the tape thickness; a second die-cutting with a second pressure value as medium pressure and a die-cutting depth controlled at 50% to 70% of the tape thickness; and a final die-cutting with a third pressure value as high pressure and a die-cutting depth controlled at 100% of the tape thickness. During the die-cutting process, cooling gas is continuously sprayed into the die-cutting area to perform an online cooling process to reduce the temperature of the cutting edge of the tool; Collect and discharge die-cut waste materials to collect individual insulating components.

[0006] In some exemplary embodiments, during the die-cutting process, the radial gap between the upper and lower dies used for die-cutting is controlled to be 5% to 8% of the total thickness of the composite insulating material tape, and the cutting edge of the die is provided with a micro-rounded corner of R0.01 to 0.03 mm.

[0007] In some exemplary embodiments, the first pressure value is set to 0.2~0.4MPa, the second pressure value is set to 0.5~0.9MPa, and the third pressure value is set to 1.2~1.6MPa.

[0008] In some exemplary embodiments, the method further includes: obtaining the thickness parameter of the high pressure-resistant substrate layer; when the thickness parameter of the high pressure-resistant substrate layer is greater than a predetermined thickness, laser pre-marking is performed on the high pressure-resistant substrate layer according to a predetermined marking parameter before performing the die-cutting process, and the depth of the laser pre-marking is 40%-60% of the thickness parameter of the high pressure-resistant substrate layer.

[0009] In some exemplary embodiments, the predetermined scribing parameters include: laser power of 10-30W, scanning speed of 500-2000 mm / s, focal spot diameter of 30-50μm, and ablation width of 0.1-0.2 mm.

[0010] In some exemplary embodiments, during the die-cutting process, the initial die-cut is set to cut only the soft functional layer, and the die-cutting depth during the initial die-cut is set according to a first depth calculation formula, which is: D 1% =H func / H total ×100%+α, where, D 1% H represents the percentage of the initial die-cut depth to the thickness of the strip. func H represents the thickness of the soft functional layer. total Where α is the thickness of the strip, and α is the process allowance, which is 5-10%. The secondary die-cutting is set to cut through the soft functional layer and form a pre-etched depth on the high-pressure-resistant substrate layer. The die-cutting depth during the secondary die-cutting is set according to the second depth calculation formula, where the first depth calculation formula is: D 2% = (H) func +β⋅H base ) / H total ×100%+α, where H base β represents the thickness of the high-pressure-resistant substrate layer, and β is the pre-etching depth ratio, which is 10-20%.

[0011] In some exemplary embodiments, the continuous injection of cooling gas into the die-cutting area to perform an online cooling process specifically includes: When the die is in the die-cutting pressing stage, cooling gas is sprayed into the die-cutting area at the maximum airflow rate to quickly cool the die. When the die is in the die-cutting return stage, cooling gas is sprayed into the die-cutting area at an opening of 20% to 40% of the maximum airflow to maintain positive pressure and prevent dust. When the die-cutting mold is idle for more than the predetermined time, cooling gas is sprayed into the die-cutting area at the minimum air flow rate or the cooling gas is turned off.

[0012] In some exemplary embodiments, when spraying cooling gas, the angle between the cooling gas spray angle and the cutting edge of the die is set to 15~30°, and the air outlet gap is 0.12-0.2mm; When the cooling gas is injected at the maximum airflow rate, the cooling parameters are controlled as follows: air outlet velocity 40~60 m / s, airflow per meter blade length 0.8~1.2 m³ / min·m.

[0013] In some exemplary embodiments, when performing vacuum defoaming treatment, the vacuum degree is controlled to be ≤-90kPa and the treatment time is 5~15s.

[0014] In some exemplary embodiments, during the constant temperature curing process, the constant temperature curing temperature is controlled at 50~70℃ and the curing time is 15~25min.

[0015] In summary, compared with the prior art, the present invention has the following beneficial effects: This invention provides a composite die-cutting method for high-voltage battery module insulation components, comprising: unwinding a high-voltage substrate layer and a soft functional layer separately, and controlling the interlayer alignment deviation to be less than a predetermined deviation threshold; stacking the materials of each layer in a predetermined order and performing roll pressing composite, then performing vacuum defoaming treatment to eliminate interlayer bubbles, and then performing constant temperature curing treatment to obtain a composite insulation strip; performing die-cutting processing on the composite insulation strip according to a graded die-cutting mode to obtain individual insulation components, wherein the graded die-cutting mode includes: initial die-cutting with a first pressure value as light pressure and controlling the die-cutting depth to be 20% to 30% of the strip thickness; second die-cutting with a second pressure value as medium pressure and controlling the die-cutting depth to be 50% to 70% of the strip thickness; and final die-cutting with a third pressure value as high pressure and controlling the die-cutting depth to be 100% of the strip thickness; continuously spraying cooling gas into the die-cutting area during the die-cutting process to perform an online cooling process to reduce the cutting edge temperature of the tool; and collecting and discharging die-cutting waste to obtain individual insulation components. This invention controls the deviation of each layer through interlayer correction, ensuring the accuracy of the formed composite insulating tape and providing a precise layer reference for subsequent die-cutting. After vacuum defoaming to eliminate interlayer bubbles and constant temperature curing to release internal stress, it can effectively avoid bulging in subsequent die-cutting and improve die-cutting quality. Die-cutting is carried out through a three-stage die-cutting method, gradually increasing the cutting depth, reducing edge chipping of the pressure-resistant substrate layer and stringing of the soft functional layer, thereby reducing burr defects and ensuring the insulation and pressure resistance performance of the insulating component. During the die-cutting process, continuous online cooling is carried out to prevent the pressure-resistant substrate layer from softening due to excessive tool temperature, thus preventing the pressure-resistant substrate layer from undergoing plastic flow rather than brittle fracture under the pushing of the tool edge, which would lead to a significant increase in burr size. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process flow for the composite die-cutting method of high-voltage battery module insulation components in an embodiment of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figure 1 As shown, this embodiment of the invention provides a composite die-cutting method for high-voltage battery module insulation components, including: S100. Unwind the high-pressure-resistant substrate layer and the soft functional layer separately, and control the interlayer alignment deviation to be less than a predetermined deviation threshold.

[0019] Specifically, high-voltage-resistant substrate layers can be made of high-dielectric-strength substrates such as FR-4 (epoxy fiberglass), mica composite board, and PEEK (Polyetheretherketone). The thickness of the high-voltage-resistant substrate layer is usually 0.3-3.0mm. As a voltage-resistant insulating substrate, FR-4 is usually used as the high-voltage-resistant substrate layer for energy storage end plate insulation boards, mica composite board is used as the high-voltage-resistant substrate layer for battery module side protection boards, and PEEK is used as the high-voltage-resistant substrate layer for 800V high-voltage platform insulation components. The flexible functional layer may include, for example, PET / PI insulating film, double-sided pressure-sensitive adhesive, flame-retardant release film, etc., which are stacked in sequence. These film materials can be independently unwound by existing unwinding devices. During the unwinding process, the alignment deviation between layers is monitored in real time by a correction sensor. The predetermined deviation threshold can be set to, for example, 0.02 mm. That is, if the deviation exceeds the threshold during the unwinding process, the correction action is automatically triggered. The correction action is to fine-tune the lateral position of the film strip. In practical applications, the correction sensor can be visually identified by a CCD camera. By identifying the deviation of the edge of the film strip, it can be determined whether the alignment deviation between layers is less than the predetermined deviation threshold.

[0020] Typically, the unwinding tension needs to be controlled within a suitable range when unwinding the film material. For example, the unwinding tension of PET / PI film is configured as 0.8-1.2N, and the unwinding tension of FR-4 / mica is configured as 2.0-3.5N. In some embodiments, a buffer layer made of materials such as foam can also be provided between the high pressure resistant substrate layer and the soft functional layer. The unwinding tension of the foam buffer layer can be configured as 3-5N.

[0021] S200: After stacking and rolling the materials in a predetermined order, vacuum defoaming treatment is performed to eliminate interlayer bubbles, followed by constant temperature curing treatment to obtain composite insulation tape.

[0022] Specifically, the layers of material are arranged in a predetermined order when unwound. When passing through the composite roller, the layers are stacked in the predetermined order. The composite roller applies pressure to each layer to achieve roll pressing and bonding. The roll pressing and bonding process can be carried out using existing technology, so it will not be described in detail here. After the bonding is completed, the composite strip is sent into a vacuum chamber for vacuum defoaming treatment. During the vacuum defoaming treatment, the vacuum degree is controlled to be ≤-90kPa and the treatment time is 5~15s. After defoaming, the composite strip is subjected to constant temperature curing treatment. During the treatment, the constant temperature curing temperature is controlled to be 50~70℃ and the curing time is 15~25min. The constant temperature curing treatment can release internal stress and avoid bulging after die cutting.

[0023] S300. The composite insulating tape is die-cut according to a graded die-cutting mode to obtain individual insulating components. The graded die-cutting mode includes: a first die-cutting with a first pressure value as light pressure and controlling the die-cutting depth to be 20% to 30% of the tape thickness; a second die-cutting with a second pressure value as medium pressure and controlling the die-cutting depth to be 50% to 70% of the tape thickness; and a final die-cutting with a third pressure value as high pressure and controlling the die-cutting depth to be 100% of the tape thickness. Specifically, the die-cutting process uses an upper and lower die-cutting mechanism. The lower die-cutting mainly serves as a support platform, which can be a flat plate or a concave die with a cutting cavity. The upper die-cutting moves downward according to a preset pressure value to complete the die-cutting action. During the die-cutting process, the radial gap between the upper and lower dies used for die-cutting is controlled to be 5% to 8% of the total thickness of the composite insulating material tape, and the cutting edge of the die-cutting is provided with a micro-rounded corner of R0.01 to 0.03 mm. Specifically, the radial gap between the upper and lower dies refers to the single-sided fitting gap from the inner and outer sides of the cutting edge of the upper die-cutting to the inner side of the upper cutting cavity of the concave die.

[0024] In this embodiment, the first pressure value is set to 0.2~0.4MPa, the second pressure value is set to 0.5~0.9MPa, and the third pressure value is set to 1.2~1.6MPa. It can be understood that during the die-cutting process, three-stage die-cutting actions are performed. The three stages are cut at the same position, but the die-cutting pressure and die-cutting depth are different. The first die-cutting control only cuts the soft functional layer. When a buffer layer is configured, the first die-cutting needs to cut both the soft functional layer and the buffer layer at the same time. The second die-cutting control cuts through the soft functional layer and the buffer layer and forms a pre-etched depth on the high pressure resistant substrate layer. The third die-cutting control completely cuts off the substrate.

[0025] In a specific example, the first pressure value P1, the second pressure value P2, and the third pressure value P3 can be determined by combining empirical formulas and equipment parameters. Taking a composite insulating tape composed of a high-voltage-resistant substrate layer, a buffer layer, and a soft functional layer as an example, let the tape thickness be H. total The thickness of the soft functional layer is H. func The thickness of the buffer layer is H mid The thickness of the high-pressure resistant substrate layer is H. base The perimeter of the die-cutting outline is L, and the projected area of ​​the die is A. die Equipment hydraulic / pneumatic system conversion factor K eq , where K eq The value can typically be between 5 and 8; Where, P1 = (τ func ·H func )·L·K eq / A die , where τ funcThe equivalent shear strength of the soft functional layer is typically 40-60 MPa for PEF and 60-80 MPa for PI. The thickness of the adhesive layer is negligible due to its extremely small thickness. Based on this, the first pressure value P1 is finally calculated to be 0.2~0.4 MPa. P2=[(τ func ·H func )+(τ base ·β·H base ·η pre )] ·L·K eq / A die , where τ base For the equivalent shear strength of the high-pressure-resistant substrate layer, FR-4 is typically 80-120 MPa, mica is 30-50 MPa, and PEEK is 60-90 MPa. The β pre-etch depth ratio is typically 10-20%, and η... pre To pre-etch the drag coefficient, since pre-etching only leaves shallow marks, η is typically... pre Taking a value of 0.4-0.6, the second pressure value P2 was finally calculated and set to 0.5~0.9MPa; P3 = (K base ·H base +τ func ·H func )·L·K eq / A die , where K base For high-pressure-resistant substrate layer die-cutting experience coefficients, FR-4 is typically 120–150 N / mm²·mm, mica is 80–100 N / mm²·mm, and PEEK is 100–130 N / mm²·mm. Based on this, the third pressure value P3 is finally calculated and set to 1.2~1.6MPa.

[0026] Furthermore, the die-cutting depth during the initial die-cutting is specifically set according to the first depth calculation formula, which is: D 1% = H func / H total ×100%+α, where, D 1% H represents the percentage of the initial die-cut depth to the thickness of the strip. func H represents the thickness of the soft functional layer. total Where α is the thickness of the strip, and α is the process allowance, which is 5-10%. The die-cutting depth during secondary die-cutting is specifically set according to the second depth calculation formula, and the first depth calculation formula is: D 2% = (H) func +β⋅H base ) / H total ×100%+α, where H baseβ represents the thickness of the high-pressure-resistant substrate layer, and β is the pre-etching depth ratio, which is 10-20%.

[0027] S400. Obtain the thickness parameter of the high pressure resistant substrate layer. When the thickness parameter of the high pressure resistant substrate layer is greater than the predetermined thickness, before performing the die-cutting process, the high pressure resistant substrate layer is laser pre-marked according to the predetermined marking parameter, and the depth of the laser pre-marking is 40%-60% of the thickness parameter of the high pressure resistant substrate layer.

[0028] The predetermined thickness is set differently depending on the material. Typically, it is 1.5-2mm for FR-4, preferably 2mm; 1-1.2mm for mica, preferably 1.2mm; and 2-2.5mm for PEEK, preferably 2.5mm. The selection of the predetermined thickness is usually determined based on the chipping rate, the 2700 VDC / 60 s throughput, and the cutting edge life. For example, the edge threshold is set as follows: chipping rate > 1.5%, 2700 VDC / 60 s throughput < 99%, and cutting edge life < 180,000 strokes.

[0029] To achieve laser marking, in actual operation, the lower die is made of transparent materials such as quartz glass or transparent PC (polycarbonate). When using quartz glass, the thickness of the lower die is usually set to 3-5mm; when using transparent PC, the thickness is usually set to 5-8mm. A laser pre-marking platform is set above the die-cutting equipment and below the lower die. The laser pre-marking platform includes a servo drive mechanism and a laser head. The servo drive mechanism is a horizontal linear drive mechanism used to drive the laser head to scan and etch along the die-cutting contour path below the lower die. When it is determined that laser pre-marking is required, the laser head is first driven by the servo drive mechanism to move along the die-cutting contour path. The laser head emits a laser beam that passes through the transparent lower die to perform pre-marking processing on the high-pressure resistant substrate layer.

[0030] The predetermined etching parameters include: laser power of 10-30W, scanning speed of 500-2000 mm / s, focal spot diameter of 30-50μm, and ablation width of 0.1-0.2 mm. Taking FR-4 as a high-pressure-resistant substrate layer as an example, the laser wavelength is 355nm, the laser power is 30W, the scanning speed is set to 800 mm / s when pre-etching the inner hole, the scanning speed is set to 1200 mm / s when pre-etching the outer contour, the focal spot diameter is set to 35μm, and the ablation width is set to 0.15 mm. Typically, the inner hole is pre-etched three times, and the outer contour is pre-etched twice.

[0031] In some embodiments, to prevent pre-etching dust from affecting the die-cutting quality, a negative pressure dust collection device is typically installed outside the die-cutting area. This device is positioned on the surface of the lower die or at the bottom of the composite insulating tape. The negative pressure dust collection device is activated only during the pre-etching process and stops operating after pre-etching is complete, thus avoiding any impact on die-cutting and the movement of the composite insulating tape. S500: During the die-cutting process, cooling gas is continuously sprayed into the die-cutting area to perform an online cooling process to reduce the temperature of the tool edge.

[0032] Specifically, cooling air channels are typically arranged on the upper die. These channels connect to air outlets / holes that run through the lower surface of the upper die. Cooling gas is blown out from the air outlets / holes and acts on the cutting edge of the tool on the upper die, thereby directly cooling the cutting edge. When spraying cooling gas, the angle between the spray angle and the cutting edge of the die is set to 15~30°, and the air outlet gap is 0.12-0.2mm. The spray angle can be determined by the angle of the air outlet / hole, which is determined during the die design. The supply pressure of the cooling gas is usually controlled at 0.2~0.3 MPa to ensure a balance between noise and energy consumption.

[0033] The cooling gas source can be compressed air from within the plant area or a separately configured air pump. The compressed air quality grade conforms to ISO 8573-1 standards, controlling solid particles ≤0.1μm, water content pressure dew point ≤-70℃ equivalent, and oil content ≤0.01 mg / m³. To ensure cooling quality, the cooling gas temperature is typically controlled at 15-25℃. In some embodiments, the air supply system can be configured as a refrigerated dryer, a precision filter, and a refrigerated air supply unit connected in series. The refrigerated dryer is connected to the air source and typically controls the pressure dew point at 2-10℃. During the refrigeration cooling process, the refrigerated dryer condenses and removes moisture from the air, reducing the water content of the cooling gas to below 90%. The precision filter is used for precise filtration of the cooling gas, employing a 0.01μm filter element. An activated carbon oil removal module is also typically included to prevent residual oil from falling into the cooling gas. On the material strip, the cooling air supply unit uses turbine cooling or compressor cooling to control the temperature of the cooling air at 15-25℃. Since the dew point temperature controlled by the freeze dryer is 2-10℃, blowing it directly onto the material strip will cause the adhesive layer to become locally overcooled and hardened, increasing the cutting force and affecting the service life of the die. In addition, the temperature may also cause condensation to form outside the cooling air duct and drip onto the material strip, affecting the quality of the insulation components. Therefore, the cooling air supply unit is used to control the temperature of the cooling air. The air outlet of the cooling air supply unit is connected to the cooling air duct through the air supply pipe, and finally the cooling gas with the controlled temperature is blown out from the air outlet / air hole.

[0034] Furthermore, the continuous injection of cooling gas into the die-cutting area to perform an online cooling process specifically includes: When the die is in the die-cutting pressing stage, cooling gas is sprayed into the die-cutting area at the maximum airflow rate for rapid cooling of the die. When spraying cooling gas at the maximum airflow rate, the cooling parameters are controlled as follows: air outlet velocity 40~60 m / s, airflow per meter of cutting edge length 0.8~1.2 m³ / min·m. The die-cutting pressing stage usually accounts for about 40% of the die-cutting cycle. During the pressurization period, the friction between the cutting edge and the material strip generates the most intense heat. Therefore, the maximum airflow rate is used to quickly remove the heat. This airflow rate can be controlled by a solenoid valve installed on the air supply pipe. When the opening degree of the solenoid valve is 100%, the maximum airflow rate can be achieved.

[0035] When the die is in the die-cutting return stage, cooling gas is sprayed into the die-cutting area at an opening of 20% to 40% of the maximum airflow to maintain positive pressure and prevent dust. The die-cutting dust stage usually accounts for about 60% of the die-cutting cycle. During this stage, the cutting edge of the die is separated from the material strip and will not generate heat through friction. At this time, the opening of the solenoid valve is reduced to 20% to 40%, preferably 30%, which means maintaining a small airflow in standby mode. This achieves continuous cooling and positive pressure dust prevention, while also reducing the occurrence of localized cooling and hardening of the adhesive layer caused by continuous blowing of cold air onto the material strip.

[0036] When the die-cutting mold is idle for a predetermined time, cooling gas is sprayed into the die-cutting area at the minimum air flow rate or the cooling gas is turned off. The predetermined time can be set to 5 minutes, and the minimum air flow rate can be set to control the opening of the solenoid valve to 10%. Turning off the cooling gas means turning off the solenoid valve to stop the air supply. This can completely avoid the situation where the adhesive layer becomes locally cold and hardened due to blowing cold air onto the material strip.

[0037] In a specific example, for instance: an air outlet with a 30° inclination angle is set on the upper die, the outlet gap is 0.15mm, the distance between the outlet and the cutting edge is 15~25mm, and the airflow direction is obliquely downwards towards the contact line between the cutting edge and the material strip. The air path is as follows: compressed air in the plant area → refrigerated dryer (pressure dew point set at 2~10℃) → precision filter (0.01 μm filter element, oil removal 0.01 mg / m³, conforming to ISO 8573-1 Class 1.2.1) → refrigerated air supply unit (PID temperature control 15~25℃, preferably set at 20℃) → air outlet; the air velocity at the outlet is controlled at 50 m / s, the airflow per meter of cutting edge length is 1 m³ / min·m, and the air supply pipe is wrapped with a rubber and plastic insulation layer of ≥25 mm to prevent condensation on the outer surface from dripping onto the material strip.

[0038] Furthermore, the air supply system and the main unit of the die-cutting equipment are configured to be linked by a PLC and controlled in a time-sharing manner according to the die-cutting cycle: during the three pressurization periods of the die-cutting downward movement (accounting for 40% of the cycle), cold air is blown at the maximum air volume; during the die-cutting return period (accounting for 60% of the cycle), the cold air is reduced to 30% opening to maintain positive pressure of the air knife for dust prevention; when the standby time exceeds 5 minutes and there is no die-cutting, the cold air is reduced to 10% opening or turned off.

[0039] Therefore, without a cooling system, the local temperature of the cutting tool can reach 60-80℃. When the high-temperature cutting tool contacts the material strip, the epoxy on the surface of FR4 will soften and turn white due to overheating, and the soft functional layer of PET will easily melt and filament. However, through the online cooling process, the frictional temperature rise of the cutting edge can be controlled and suppressed to within 30-40℃. This enables the following: 1) Hard and brittle substrates such as FR4 / mica / PEEK are always in a glassy brittle fracture mode during die cutting, the burr height is reduced from 22.4 μm to 3.8 μm, the chipping rate is reduced from 8.5% to 0.4%, and the 2700 VDC withstand voltage pass rate is increased from 91% to over 99%; 2) The thermal activation and overflow of the adhesive layer is suppressed, the overflow width is reduced from 0.15–0.30 mm to < 0.02 mm, and the die cleaning interval is extended by 4 times; 3) The thermal shrinkage and melting and filamentation of the soft functional layer of PET are prevented, and the dimensional accuracy is maintained at ±0.05 mm. Within; 4) Suppress the thermal sintering of die-cutting dust, with the dust existing in the form of loose powder, reducing the die indentation rate from 3-5% to <0.5%; 5) Stabilize the mechanical properties of each layer of material, so that the pressure parameters of the three-stage graded die-cutting can be used for a long time after one calibration, without the need for real-time compensation with temperature drift.

[0040] S600: Rewind and collect die-cut waste and individual insulating components. The die-cut insulating components are discharged and collected one by one, while the waste is rewound and processed.

[0041] When collecting individual insulating components, online internal pressure sampling is usually also performed. One component is taken from every 50-100 die-cut insulating components for a 2700 VDC / 60 s withstand voltage test and an insulation resistance test (≥ 500 MΩ) to determine whether the performance of the insulating component meets the standard.

[0042] The technical effects of this application are illustrated below with some specific examples: Comparative Example 1 The die-cutting pressure is controlled at 1.4 MPa, and the radial gap between the upper and lower dies is 10% of the total thickness of the composite insulation tape. The tape is completely cut off by a single heavy pressure.

[0043] Comparative Example 2 A two-stage die-cutting method is adopted. The first stage controls the die-cutting pressure at 0.8 MPa and the die-cutting depth at 30% of the material strip thickness. The second stage controls the die-cutting pressure at 1.4 MPa to completely cut the material strip. The radial gap between the upper and lower dies is 10% of the total thickness of the composite insulation material strip.

[0044] Comparative Example 3 A three-stage die-cutting method was adopted. The first die-cutting was performed at 0.3 MPa with a cutting depth controlled at 25% of the material strip thickness. The second die-cutting was performed at 0.7 MPa with a cutting depth controlled at 60% of the material strip thickness. The final die-cutting was performed at 1.4 MPa with a cutting depth controlled at 100% of the material strip thickness. The radial gap between the upper and lower dies was 6% of the total thickness of the composite insulation material strip. In this comparative example, online air cooling was not performed.

[0045] Example 1 A three-stage die-cutting method is adopted. The first die-cutting is performed at 0.3 MPa, and the die-cutting depth is controlled at 25% of the material strip thickness. The second die-cutting is performed at 0.7 MPa, and the die-cutting depth is controlled at 60% of the material strip thickness. The final die-cutting is performed at 1.4 MPa, and the die-cutting depth is controlled at 100% of the material strip thickness. The radial gap between the upper and lower dies is 6% of the total thickness of the composite insulating material strip. At the same time, during the die-cutting process, 20°C cooling gas is continuously sprayed into the die-cutting area to reduce the cutting edge temperature of the tool.

[0046] Example 2 First, a 355 nm ultraviolet laser is used for pre-etching, with the depth of the laser pre-etching being 50% of the thickness parameter of the high-pressure resistant substrate layer. Then, a three-stage die-cutting method is used. The first die-cutting is performed at 0.3 MPa, with the die-cutting depth controlled at 25% of the material strip thickness. The second die-cutting is performed at 0.7 MPa, with the die-cutting depth controlled at 60% of the material strip thickness. The final die-cutting is performed at 1.4 MPa, with the die-cutting depth controlled at 100% of the material strip thickness. The radial gap between the upper and lower dies is 6% of the total thickness of the composite insulating material strip. At the same time, during the die-cutting process, 20°C cooling gas is continuously sprayed into the die-cutting area to reduce the cutting edge temperature of the tool.

[0047] The above embodiments and comparative examples were subjected to the following tests: 1. Burr height detection: Measured using a 50× stereo microscope, and the average value of 20 points along the contour is taken; 2. Edge chipping rate detection: Visual inspection and 5× magnifying glass were used to detect the percentage of pieces with chipping ≥ 10 μm. 3. Withstand voltage test: Test at 2700 VDC / 60s, leakage current <1mA is considered passing; 4. Insulation resistance test: DC 500 V, initial test at BOL and retest after 1000 h at 85℃ / 85% RH.

[0048] The test results are shown in the table below: In summary, this invention controls the deviation of each layer through interlayer correction, ensuring the accuracy of the formed composite insulating tape and providing a precise layer reference for subsequent die-cutting. After vacuum defoaming to eliminate interlayer bubbles and constant-temperature curing to release internal stress, it effectively avoids bulging during subsequent die-cutting, improving die-cutting quality. Die-cutting is performed in three stages, gradually increasing the cutting depth, reducing edge chipping of the pressure-resistant substrate layer and stringing of the soft functional layer, thereby reducing burr defects and ensuring the insulation and pressure-resistant performance of the insulating component. Continuous online cooling during die-cutting prevents the pressure-resistant substrate layer from softening due to excessive tool temperature, thus preventing the pressure-resistant substrate layer from undergoing plastic flow rather than brittle fracture under the pressure of the tool edge, which would otherwise significantly increase the burr size.

[0049] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of these fall within the protection scope of the present invention.

Claims

1. A composite die-cutting method for insulating components of high-voltage battery modules, characterized in that, include: The high-pressure-resistant substrate layer and the soft functional layer are unwound separately, and the alignment deviation between the layers is controlled to be less than a predetermined deviation threshold. After the materials are stacked in a predetermined order and rolled and laminated, vacuum defoaming treatment is performed to eliminate interlayer bubbles, and then constant temperature curing treatment is performed to obtain composite insulation tape. The composite insulating tape is die-cut according to a graded die-cutting pattern to obtain individual insulating components. The graded die-cutting pattern includes: an initial die-cutting with a first pressure value as light pressure and a die-cutting depth controlled at 20% to 30% of the tape thickness; a second die-cutting with a second pressure value as medium pressure and a die-cutting depth controlled at 50% to 70% of the tape thickness; and a final die-cutting with a third pressure value as high pressure and a die-cutting depth controlled at 100% of the tape thickness. During the die-cutting process, cooling gas is continuously sprayed into the die-cutting area to perform an online cooling process to reduce the temperature of the cutting edge of the tool; Collect and discharge die-cut waste materials to collect individual insulating components.

2. The composite die-cutting method for high-voltage battery module insulating components according to claim 1, characterized in that, During the die-cutting process, the radial gap between the upper and lower dies used in the die-cutting process is controlled to be 5% to 8% of the total thickness of the composite insulation tape, and the cutting edge of the die is provided with a micro-rounded corner of R0.01 to 0.03mm.

3. The composite die-cutting method for high-voltage battery module insulating components according to claim 1, characterized in that, The first pressure value is set to 0.2~0.4MPa, the second pressure value is set to 0.5~0.9MPa, and the third pressure value is set to 1.2~1.6MPa.

4. The composite die-cutting method for high-voltage battery module insulating components according to claim 1, characterized in that, Also includes: The thickness parameters of the high pressure resistant substrate layer are obtained. When the thickness parameters of the high pressure resistant substrate layer are greater than the predetermined thickness, the high pressure resistant substrate layer is laser pre-marked according to the predetermined marking parameters before the die-cutting process is performed. The depth of the laser pre-marking is 40%-60% of the thickness parameters of the high pressure resistant substrate layer.

5. The composite die-cutting method for high-voltage battery module insulating components according to claim 4, characterized in that, The predetermined etching parameters include: laser power of 10-30W, scanning speed of 500-2000 mm / s, focal spot diameter of 30-50μm, and ablation width of 0.1-0.2 mm.

6. The composite die-cutting method for high-voltage battery module insulating components according to claim 1, characterized in that, During the die-cutting process, the initial die-cut is set to cut only the soft functional layer. The die-cutting depth during the initial die-cut is set according to the first depth calculation formula, which is: D 1% = H func / H total ×100%+α, where, D 1% H represents the percentage of the initial die-cut depth to the thickness of the strip. func H represents the thickness of the soft functional layer. total Where α is the thickness of the strip, and α is the process allowance, which is 5-10%. The secondary die-cutting is set to cut through the soft functional layer and form a pre-etched depth on the high-pressure-resistant substrate layer. The die-cutting depth during the secondary die-cutting is set according to the second depth calculation formula, where the first depth calculation formula is: D 2% = (H) func +β⋅H base ) / H total ×100%+α, where H base β represents the thickness of the high-pressure-resistant substrate layer, and β is the pre-etching depth ratio, which is 10-20%.

7. The composite die-cutting method for high-voltage battery module insulating components according to claim 1, characterized in that, The continuous injection of cooling gas into the die-cutting area to perform the online cooling process specifically includes: When the die is in the die-cutting pressing stage, cooling gas is sprayed into the die-cutting area at the maximum airflow rate to quickly cool the die. When the die is in the die-cutting return stage, cooling gas is sprayed into the die-cutting area at an opening of 20% to 40% of the maximum airflow to maintain positive pressure and prevent dust. When the die-cutting mold is idle for more than the predetermined time, cooling gas is sprayed into the die-cutting area at the minimum air flow rate or the cooling gas is turned off.

8. The composite die-cutting method for high-voltage battery module insulating components according to claim 7, characterized in that, When spraying cooling gas, the angle between the spray angle of the cooling gas and the cutting edge of the die should be set to 15~30°, and the air outlet gap should be 0.12-0.2mm. When the cooling gas is injected at the maximum airflow rate, the cooling parameters are controlled as follows: air outlet velocity 40~60 m / s, airflow per meter blade length 0.8~1.2 m³ / min·m.

9. The composite die-cutting method for high-voltage battery module insulating components according to claim 1, characterized in that, When performing vacuum defoaming treatment, the vacuum degree is controlled to be ≤-90kPa and the treatment time is 5~15s.

10. The composite die-cutting method for high-voltage battery module insulating components according to claim 1, characterized in that, During the constant temperature curing process, the curing temperature is controlled at 50~70℃ and the curing time is 15~25min.

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