A simulation design method for vibration-resistant installation of circuit boards

Abstract

The present invention provides a simulation design method for vibration-resistant installation of a circuit board, comprising the following steps: S1, determining the basic size and shape of the circuit board, determining the number and arrangement positions of MOS tubes, heat sinks, screw columns, circuit board pillars and other electronic components; S2, dividing the finite element model grid according to the calculation scale and model characteristics; S3, establishing the connection relationship between various components; S4, calculating the modal characteristics of the circuit board, and performing sinusoidal vibration response analysis; S5, determining the support point position of a newly added circuit board pillar according to the response situation; S6, repeating step S4 to verify the vibration-resistant ability of the circuit board after the newly added circuit board pillar. The present invention is based on finite element simulation technology, simulates the response of the circuit board under vibration conditions of different frequencies, and uses this as a design basis to add new support points in the circuit board to avoid excessive stress on the circuit board during vibration, so as to reduce the possibility of circuit board breakage.

Description

Technical Field

[0001] The invention relates to the technical field of battery structure design, and in particular to a simulation design method for vibration-resistant installation of a circuit board. Background Art

[0002] The safety of lithium batteries has always been a research focus of relevant industries. With the continuous promotion and popularization of two-wheeled vehicles such as electric motorcycles and bicycles, a large number of small battery packs have entered communities and even homes. Compared with electric vehicles, electric two-wheeled vehicles are more prone to collisions, and the driving conditions are also worse. At the same time, the battery packs also need to be disassembled and assembled. These usage environments determine the complexity of the use environment of two-wheeled vehicle battery packs, and more reliable and complete designs are required to ensure their safety during use. As the management system of the battery pack, the BMS circuit board's ability to resist vibration damage is particularly important for the entire battery system.

[0003] Generally, circuit board vibration protection designs use additional support structures to allow the circuit board to withstand flexible impacts (CN212936282U), or add additional auxiliary mechanisms to limit the deformation of the circuit board (CN213818339U).

[0004] However, the above methods often make the circuit board structure complex, with low reliability, and increase the manufacturing cost. Moreover, the above solutions are mainly used to resist vibration (large, accidental impact), without considering the problem of structural resonance caused by work excitation vibration during product use. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a simulation design method for vibration-resistant installation of a circuit board.

[0006] The technical solution of the present invention is as follows:

[0007] A simulation design method for vibration-resistant installation of a circuit board, comprising:

[0008] S1. Determine the basic size and shape of the circuit board according to the appearance structure of the battery pack, and determine the number and arrangement positions of MOS tubes, heat sinks, screw columns, circuit board pillars and other electronic components;

[0009] S2. Divide the finite element model grid according to the calculation scale and model characteristics;

[0010] S3, establish the connection relationship between each component;

[0011] S4. Calculate the modal characteristics of the circuit board and perform sinusoidal vibration response analysis;

[0012] S5. Determine the support point position of the newly added circuit board pillar according to the response situation;

[0013] S6, repeat step S4 to verify the vibration resistance of the circuit board after adding the circuit board support. If the measured stress and displacement values ​​meet the design requirements, the position of the newly added support point is retained. If not, repeat step S5 to add a support point, and repeat repeatedly until the stress and displacement values ​​meet the standards.

[0014] S7. Mark the area of ​​the circuit board with greater deformation according to the test data for reference in subsequent circuit design.

[0015] In the present invention, in step S1, the number and arrangement positions of MOS tubes, heat sinks, screw columns, circuit board pillars and other electronic components are determined according to the installation space and circuit requirements.

[0016] In the present invention, in step S2, the finite element model of the circuit board specifically includes: the circuit board, using shell unit SR4, unit size 1.2㎜, mid-surface offset; MOS tube, bolt column and other electronic components, using solid hexahedral unit C3D8, unit size 2㎜; heat sink, using shell unit SR4, unit size 2㎜, mid-surface offset; circuit board pillar, using beam unit, the cross section is a circular ring.

[0017] In the present invention, in step S3, the connection relationship between the various components includes: establishing a coupling constraint between the upper end of the circuit board pillar and the circuit board, the constraint range is 5 mm, and the lower end of the circuit board pillar uses a completely fixed constraint; the MOS tube and other electronic components are connected to the circuit board using connection units to simulate solder joints, the number of connection units is consistent with the number of solder joints, and the connection stiffness is 100N / mm; the MOS tube and the heat sink and the upper and lower contact surfaces of the bolt column are connected using a binding connection relationship.

[0018] In the present invention, in step S4, after the lanczoc method is used to extract the modes within 1000 Hz, the modal superposition method is used to obtain the results within 7-200 Hz to obtain the response results of the circuit board at different frequencies.

[0019] Furthermore, in the modal superposition method, the modal damping coefficient is set to 0.03, the basic motion is set to acceleration, the acceleration magnitude varies with the frequency, the acceleration magnitude is 1g at 7-18Hz, the acceleration magnitude increases linearly to 8g at 18-50Hz, and remains unchanged at 8g at 50-200Hz; the acceleration is applied in the vertical direction accordingly.

[0020] Furthermore, the response result includes stress amplitude, displacement amplitude and acceleration amplitude.

[0021] Furthermore, in step S5, the acceleration amplitude of the circuit board at each node in the response result is extracted. If the curve has a single or multiple peaks, the response of the corresponding frequency at the peak point is extracted, the original coordinates and deformation displacement of the maximum displacement point are obtained, and the frequency (f1, f2, ...) corresponding to the acceleration peak point is found. In the results corresponding to the frequency (f1, f2, ...), the displacement (Δz1, Δz2, ...) at the point where the displacement amplitude of the circuit board is the largest and its corresponding coordinates (x1, y1), (x2, y2) ... are searched, and the weighting coefficient is calculated according to the displacement. Calculate the coordinates of the new support point (x new ,y new )

[0022]

[0023] If there is no peak, select the response result at 200 Hz to determine whether the stress amplitude and displacement amplitude meet the requirements; if not, add a new support point at the maximum displacement response.

[0024] In the present invention, in step S6, the design requirements include the maximum displacement magnitudes in the x, y, and z axis directions, the tension magnitude at the connection of the MOS tube, and the mises stress magnitude of the circuit board.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] The present invention is based on finite element simulation technology, which simulates the response of the circuit board under vibration conditions of different frequencies, and uses this as a design basis to add new support points in the circuit board to avoid excessive stress on the circuit board during vibration, so as to reduce the possibility of circuit board breakage. No additional auxiliary structure is required, the installation is simple, the reliability is high, and the vibration-resistant design is more targeted. At the same time, the area of ​​the circuit board with large deformation is pointed out to avoid the arrangement of components that are easy to desolder in this area, which can effectively shorten the design cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 The present invention provides a flow chart of a simulation design method for vibration-resistant installation of a circuit board. DETAILED DESCRIPTION

[0029] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred components or elements must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] In order to illustrate the technical solution of the present invention, a specific embodiment is provided below for illustration.

[0032] Example

[0033] See also Figure 1 This embodiment provides a simulation design method for vibration-resistant installation of a circuit board, including:

[0034] S1. Determine the basic size and shape of the circuit board according to the appearance structure of the battery pack, and determine the number and arrangement positions of MOS tubes, heat sinks, screw columns, circuit board pillars and other electronic components;

[0035] S2. Divide the finite element model grid according to the calculation scale and model characteristics;

[0036] S3, establish the connection relationship between each component;

[0037] S4. Calculate the structural response of the circuit board under sinusoidal vibration and perform sinusoidal vibration response analysis;

[0038] S5. Determine the support point position of the newly added circuit board pillar according to the response situation;

[0039] S6, repeat step S4 to verify the vibration resistance of the circuit board after adding the circuit board support. If the measured stress and displacement values ​​meet the design requirements, the position of the newly added support point is retained. If not, repeat step S5 to add a support point, and repeat repeatedly until the stress and displacement values ​​meet the standards.

[0040] S7. Mark the area of ​​the circuit board with greater deformation according to the test data for reference in subsequent circuit design.

[0041] In this embodiment, in step S1, the number and arrangement positions of MOS tubes, heat sinks, screw columns, circuit board pillars and other electronic components are determined according to the installation space and circuit requirements.

[0042] In this embodiment, in step S2, the finite element model of the circuit board specifically includes: the circuit board, using shell elements SR4, the element size is 1.2 mm, and the mid-surface is offset; the MOS tube, bolt column and other electronic components, using solid hexahedral elements C3D8, the element size is 2 mm; the heat sink, using shell elements SR4, the element size is 2 mm, and the mid-surface is offset; the circuit board pillar, using beam elements, the cross section is a circular ring.

[0043] In this embodiment, in step S3, the connection relationship between the various components includes: establishing a coupling constraint between the upper end of the circuit board pillar and the circuit board, the constraint range is 5 mm, and the lower end of the circuit board pillar uses a completely fixed constraint; the MOS tube and other electronic components are connected to the circuit board using connection units to simulate solder joints, the number of connection units is one of the number of solder joints, and the connection stiffness is 100N / mm; the MOS tube and the heat sink and the upper and lower contact surfaces of the bolt column are connected using a binding connection relationship.

[0044] In this embodiment, in step S4, after the modes within 1000 Hz are extracted using the lanczoc method, the modal superposition method is used to obtain the results within 7-200 Hz to obtain the response results of the circuit board at different frequencies.

[0045] Furthermore, in the modal superposition method, the modal damping coefficient is set to 0.03, the basic motion is set to acceleration, the acceleration magnitude varies with the frequency, the acceleration magnitude is 1g at 7-18Hz, the acceleration magnitude increases linearly to 8g at 18-50Hz, and remains unchanged at 8g at 50-200Hz; the acceleration is applied in the vertical direction accordingly.

[0046] Furthermore, the response results include stress amplitude, displacement amplitude and acceleration amplitude.

[0047] Furthermore, in step S5, the acceleration amplitude of the circuit board at each node in the response result is extracted. If the curve has a single or multiple peaks, the response of the corresponding frequency at the peak point is extracted, the original coordinates and deformation displacement of the maximum displacement point are checked, and the frequency (f1, f2, ...) corresponding to the acceleration peak point is found. In the results corresponding to the frequency (f1, f2, ...), the displacement (Δz1, Δz1, ...) at the point where the displacement amplitude of the circuit board is the largest and its corresponding coordinates (x1, y1), (x2, y2) ... are searched, and the weighting coefficient is calculated according to the displacement. Calculate the coordinates of the new support point (x new ,y new )

[0048]

[0049] If there is no peak, select the response result at 200 Hz to determine whether the stress amplitude and displacement amplitude meet the requirements; if not, add a new support point at the maximum displacement response.

[0050] In this embodiment, in step S6, the design requirements include the maximum displacement magnitudes in the x, y, and z axis directions, the tension magnitude at the connection of the MOS tube, and the mises stress magnitude of the circuit board.

[0051] Working principle:

[0052] Based on finite element simulation technology, the response of the circuit board under vibration conditions of different frequencies is simulated, and based on this, new support points are added to the circuit board to avoid excessive stress on the circuit board during vibration, thereby reducing the possibility of circuit board breakage.

[0053] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A simulation design method for vibration-resistant installation of a circuit board, characterized in that: The following steps are involved: S1. Determine the basic size and shape of the circuit board according to the appearance structure of the battery pack, and determine the number and arrangement positions of MOS tubes, heat sinks, screw columns, circuit board pillars and other electronic components; S2. Divide the finite element model grid according to the calculation scale and model characteristics; S3, establish the connection relationship between each component; S4. Calculate the modal characteristics of the circuit board and perform sinusoidal vibration response analysis; S5. Determine the support point position of the newly added circuit board pillar according to the response situation; extract the acceleration amplitude of the circuit board at each different node in the response result. If the curve has a single or multiple peaks, extract the response of the corresponding frequency at the peak point, check the original coordinates and deformation displacement of the maximum displacement point, and find the frequency corresponding to the acceleration peak point (f1, f2, ... f n ); at frequencies (f1, f2, ...f n ) in the corresponding results to find the displacement (Δz1, Δz2, ... Δz n ) and its corresponding coordinates (x1, y1), (x2, y2)...(x n ,y n ), calculate the weighting coefficient based on the displacement Calculate the coordinates of the new support point (x new ,y new ) If there is no peak, select the response result at 200 Hz to determine whether the stress amplitude and displacement amplitude meet the requirements; if not, add a new support point at the maximum displacement response. S6, repeat step S4 to verify the vibration resistance of the circuit board after adding the circuit board support. If the measured stress and displacement values ​​meet the design requirements, the position of the newly added support point is retained. If not, repeat step S5 to add a support point, and repeat repeatedly until the stress and displacement values ​​meet the standards. S7. Mark the area of ​​the circuit board with greater deformation according to the test data for reference in subsequent circuit design.

2. The simulation design method for vibration-resistant installation of a circuit board according to claim 1, characterized in that: In step S1, the number and arrangement positions of MOS tubes, heat sinks, screw posts, circuit board posts and other electronic components are determined according to the installation space and circuit requirements.

3. The simulation design method for vibration-resistant installation of a circuit board according to claim 1, characterized in that: In the step S2, the finite element model of the circuit board specifically includes: the circuit board, using shell elements SR4, the element size is 1.2 mm, and the mid-surface is offset; the MOS tube, bolt column and other electronic components, using solid hexahedral elements C3D8, the element size is 2 mm; the heat sink, using shell elements SR4, the element size is 2 mm, and the mid-surface is offset; the circuit board pillar, using beam elements, the cross section is a circular ring.

4. The simulation design method for vibration-resistant installation of a circuit board according to claim 1, characterized in that: In the step S3, the connection relationship between the various components includes: establishing a coupling constraint between the upper end of the circuit board pillar and the circuit board, the constraint range is 5 mm, and the lower end of the circuit board pillar uses a completely fixed constraint; the MOS tube and other electronic components are connected to the circuit board using connection units to simulate solder joints, the number of connection units is consistent with the number of solder joints, and the connection stiffness is 100N / mm; the MOS tube and the heat sink and the upper and lower contact surfaces of the bolt column are connected using a binding connection relationship.

5. The simulation design method for vibration-resistant installation of a circuit board according to claim 1, characterized in that: In the step S4, after the modes within 1000 Hz are extracted using the lanczoc method, the modal superposition method is used to calculate the sinusoidal vibration results within 7-200 Hz to obtain the structural responses of the circuit board at different frequencies.

6. The simulation design method for vibration-resistant installation of a circuit board according to claim 5, characterized in that: In the solution of the sinusoidal vibration results, the modal damping coefficient is set to 0.03, the basic motion is set to acceleration, the acceleration magnitude varies with the frequency, the acceleration magnitude is 1g at 7-18Hz, the acceleration magnitude increases linearly to 8g at 18-50Hz, and remains unchanged at 8g at 50-200Hz; the acceleration direction is applied perpendicular to the plane of the circuit board.

7. The simulation design method for vibration-resistant installation of a circuit board according to claim 5, characterized in that: The response results include stress amplitude, displacement amplitude and acceleration amplitude.

8. The simulation design method for vibration-resistant installation of a circuit board according to claim 1, characterized in that: In step S6, the design requirements include the maximum displacement magnitudes in the x, y, and z axis directions, the tension magnitude at the connection of the MOS tube, and the mises stress magnitude of the circuit board.

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