An automated production process for a power bank module

Abstract

This invention discloses an automated production process for jump-start modules, comprising the following steps: TU2 oxygen-free copper coils are pre-treated and fed into a continuous stamping station via a servo feeding mechanism; a multi-station progressive die completes punching, hole punching, reinforcing rib stamping, adaptive floating spring arm and biomimetic micro-texture forming, bending and cutting to obtain a semi-finished product; the semi-finished product is deburred and the contact patches are leveled; after cleaning and drying, the workpiece undergoes gradient plating and passivation via a segmented electroplating production line to form a mechanical anchoring structure for the plating layer; finally, online inspection is performed, and qualified parts are bent, sorted, and packaged to obtain the finished product. This invention uses an adaptive floating spring arm and biomimetic micro-texture integrated with the workpiece for continuous stamping, eliminating assembly errors and contact hazards associated with separate structures. The floating structure adapts to the shape and position deviations of the battery terminals, and the biomimetic micro-texture reconstructs the conductive mode of the contact interface, significantly increasing the effective bonding area and the number of microscopic conductive contacts, thereby reducing the initial contact resistance from the source.

Description

Technical Field

[0001] This invention relates to the field of automotive emergency starter accessories technology, and in particular to an automated production process for jump start modules. Background Technology

[0002] The automotive jump starter module is a core conductive component for emergency vehicle starting. It needs to instantaneously carry a large current to complete the conduction work, which directly determines the safety and stability of emergency starting. The industry has strict standards for the conductivity, structural strength and durability of this component. Currently, the industry mainly relies on conventional stamping and electroplating processes to achieve mass production of products to meet the basic supply and usage needs of automotive emergency starting accessories.

[0003] Existing jump-start modules have inherent defects in their manufacturing processes and structural designs that are difficult to overcome. Under high current impact, these products are prone to contact failure and thermal runaway cascading failures. Traditional rigid contact structures cannot adapt to the shape and position deviations of battery terminals, and insufficient effective contact area leads to a rapid increase in local resistance. Simply optimizing flatness or improving the plating alone cannot provide effective protection. The plating is easily eroded and peeled off by heat. Poor contact and overheating problems exacerbate each other, ultimately leading to safety risks such as arcing and component burning, and failing to guarantee safe use under extreme conditions.

[0004] Therefore, it is necessary to provide an automated production process for jump-start modules to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention overcomes the core defect of existing automotive jump-start modules in the case of contact failure-thermal runaway cascading failure under high current impact, and provides an automated production process for jump-start modules.

[0006] This process forms a complete protection closed loop through two sets of deeply coupled core technical features, fundamentally blocking the fault chain from contact failure to thermal runaway, and comprehensively improving the high-current conduction reliability, structural stability and environmental tolerance of the jump-start module.

[0007] To achieve the above objectives, the technical solution adopted by this invention is: an automated production process for jump-start modules, comprising the following steps:

[0008] S1. After the TU2 oxygen-free copper coil is unwound, leveled, and ultrasonically degreased, it is fed into the continuous stamping station at a fixed step distance through a servo feeding mechanism. This provides a substrate that meets the precision requirements for subsequent continuous precision stamping, ensuring the consistency of workpiece forming and the conductivity of the substrate from the raw material end.

[0009] S2. Through multi-station progressive dies, the workpiece is continuously punched, punched, structural reinforcing rib stamped, adaptive floating spring arm preformed, contact patch biomimetic micro-texture embossed, and finally bent and cut to produce a semi-finished workpiece. The integrated continuous forming process eliminates the additional contact resistance and breakage risk of the split structure, and simultaneously solves the core problems of insufficient fit between traditional rigid contact patches and battery terminals, small effective contact area, and uneven surface pressure distribution. At the same time, it constructs a special structural foundation for the mechanical anchoring of the subsequent coating.

[0010] S3. The blanking section of the semi-finished workpiece is deburred by a double-sided flexible roller brush, and the contact patch working surface is precisely leveled by a dual-servo diamond roller. This process eliminates the interference of the stamping burrs on the contact bonding, ensures the basic bonding accuracy of the contact patch working surface, and further amplifies the contact optimization effect of adaptive floating bonding and biomimetic micro-texture.

[0011] S4. After leveling the workpiece, perform normal pressure low temperature plasma surface cleaning to thoroughly remove oil and oxide layer from the workpiece surface. Then, perform hot air circulation drying. This process removes all impurities from the workpiece surface and micro-texture pits, providing a clean and highly active interface for subsequent in-situ coating growth and ensuring the bonding strength between the coating and the substrate.

[0012] S5. The dried workpiece is fed into a segmented electroplating production line. A pulsed power supply and a directional ultrasonic stirring system are used to sequentially complete the pre-plating of copper, the intermediate layer of nickel-phosphorus alloy, the surface layer of tin-bismuth alloy, and chromium-free passivation treatment. A mechanical anchoring structure for the plating is formed in the pits of the biomimetic microtexture. This process is the second core technology process of this invention. It is precisely matched with the biomimetic microtexture structure of process S2 to form a complete closed loop of "innate contact optimization + acquired failure protection". The two processes are mutually dependent and mutually reinforcing. Using the contact optimization structure of process S2 alone cannot solve the problems of plating softening, peeling, and contact resistance rebound under high current impact. Using the plating process of this process alone cannot solve the problem of instantaneous high-temperature ablation caused by poor initial contact. After the two processes are coupled, the heat generated during high current operation is reduced from the source, and the contact self-repair under extreme conditions is achieved through the anchoring gradient plating, completely blocking the chain failure of contact failure-thermal runaway.

[0013] S6. Perform full-parameter online detection on the electroplated workpiece, automatically reject unqualified products, and after the qualified workpieces are precision bent and formed at the terminals, graded, sorted and vacuum packaged, the finished power-on module is obtained.

[0014] In a preferred embodiment of the present invention, in S2, the adaptive floating elastic arm is a C-shaped elastic support arm symmetrically arranged on both sides of the contact patch, which is integrally stamped with the contact patch. The integrally formed structure has no welding and no secondary clamping, eliminating the additional contact resistance and breakage risk of the separate welded structure.

[0015] The C-shaped symmetrical structure achieves stable adaptive floating compensation, covering the form and position tolerances and clamping angle deviations of the battery terminals. This ensures that the contact patch fully adheres to the arc surface of the battery terminal, effectively increasing the contact area and eliminating the problem of excessively high local current density at its source. The biomimetic micro-texture is a honeycomb-shaped array of micron-level pits imprinted on the working surface of the contact patch. This structure transforms traditional surface contact into a composite contact mode combining surface contact with thousands of micron-level points, increasing the number of actual conductive contact points and reducing initial contact resistance. At the same time, the pit structure provides a mechanical anchoring interface for the coating.

[0016] In a preferred embodiment of the present invention, the diameter of the honeycomb-shaped micron-sized pits is 30-50 μm, the depth is 8-12 μm, and the spacing between adjacent pits is 60-80 μm. This ensures that a sufficient number of micron-sized conductive contact points are formed to reduce contact resistance, and also forms a stable mechanical anchoring structure for the coating. This avoids the problems of reduced coating adhesion and insufficient contact optimization effect caused by pit size exceeding the limit. It also precisely matches the electroplating process parameters to ensure the stable implementation of synergistic effects.

[0017] In a preferred embodiment of the present invention, in S2, the unidirectional floating stroke of the adaptive floating spring arm is 0.3-0.5mm, the springback amount is 0.01-0.05mm, and the arc transition radius at the C-shaped bend is 1.2-1.5mm. This floating stroke covers the battery terminal form and position tolerance and clamping angle deviation, ensuring stable fit across the entire working surface; the springback range ensures stable clamping force output, avoiding insufficient surface pressure caused by excessive springback; the arc transition structure eliminates stress concentration at the bend, ensuring fatigue resistance for more than 1000 reciprocating clamping cycles, maintaining stable fit even after long-term use, and providing a guarantee for contact stability under high current conditions.

[0018] In a preferred embodiment of the present invention, in S2, the multi-station progressive die has 12-16 stations. During the stamping process, dynamic compensation of the die clearance is completed once every two stamping strokes. The stamping speed is 60-80 rpm. The 12-16 station progressive die layout realizes the integrated continuous forming of the adaptive floating spring arm, the biomimetic micro-texture and the workpiece body, without secondary clamping and positioning errors. The dynamic compensation of the die clearance eliminates the influence of die wear during the stamping process, ensures the imprinting accuracy of the micro-texture and the consistency of the floating spring arm forming, and reduces the performance fluctuation of batch products.

[0019] In a preferred embodiment of the present invention, in S3, the flatness of the working surface of the contact patch after leveling is 0.005-0.02 mm / m. This flatness range ensures the basic bonding accuracy between the contact patch and the battery terminal, complements the adaptive floating spring arm, increases the effective contact area, and avoids local contact problems caused by warping of the working surface.

[0020] In a preferred embodiment of the present invention, in S5, the thickness of the pre-plated copper layer is 3-5 μm, and the pre-plated copper layer completely fills the bottom corners of the microtextured pits to form a stable plating anchoring structure. The thickness of the nickel-phosphorus alloy intermediate layer is 2-4 μm. The nickel-phosphorus alloy intermediate layer can withstand instantaneous high temperatures above 300°C, blocking heat conduction to the substrate and avoiding thermal deformation of the substrate. The thickness of the tin-bismuth alloy surface layer is 8-10 μm. The tin-bismuth alloy surface layer achieves micro-melting self-repair when slightly heated, fills the gaps at the contact interface, and precisely matches the biomimetic microtextured structure to achieve dynamic stability of contact resistance.

[0021] In a preferred embodiment of the present invention, in S5, the vibration frequency of the directional ultrasonic stirring is 40-60kHz, and the vibration direction is consistent with the opening direction of the biomimetic microtexture pit. This can eliminate the bubble retention and electroplating solution shielding effect in the microtexture pit, ensure that the electroplating solution completely enters the pit, achieve uniform growth of the coating in the pit, and eliminate problems such as missed plating and uneven thickness, thus ensuring the stable formation of the coating anchoring structure.

[0022] In a preferred embodiment of the present invention, in S5, the pre-plated copper is pre-plated using pulse electroplating with a current density of 2-3 A / dm². Pulse electroplating enhances the ability of the plating layer to penetrate deep into the micro-textured pits, ensuring the uniformity of the plating layer on the inner wall and bottom surface of the pits, and providing a foundation for the formation of the anchoring structure. The nickel-phosphorus alloy intermediate layer is plated using DC pulse composite electroplating. The bismuth content in the plating layer of the tin-bismuth alloy surface layer is 3-5 wt%. When a slight heat is generated during high-current operation, micro-melting self-lubrication can be achieved, automatically filling the gap between the micro-textured pits and the contact interface, and achieving a self-repairing effect where the contact resistance decreases instead of increasing.

[0023] In a preferred embodiment of the present invention, in S6, the online detection includes microtexture integrity detection, high current contact resistance detection, coating thickness and adhesion detection, and floating spring fatigue strength detection. The four detection items directly correspond to the key performance indicators of the two sets of core technical features, realizing full inspection of core performance effects and preventing defective products from leaving the market.

[0024] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0025] (1) This invention provides an automated production process for a jump-start module. By adopting an adaptive floating spring arm and a biomimetic micro-texture and workpiece body integral continuous stamping, the integral molding process eliminates the assembly error and contact hazards caused by the split structure. The floating structure can adapt to the shape and position deviation of different battery terminals. The biomimetic micro-texture reconstructs the conductivity mode of the contact interface, greatly increases the effective bonding area between the contact patch and the battery terminal, increases the number of micro-conductive contact points, and reduces the initial contact resistance from the source. Unlike the existing technology that only optimizes the flatness or improves the structure, it cannot solve the core problems of poor rigid bonding and insufficient contact points. It completely avoids the heat generation hazards caused by excessive local current density and lays a solid foundation for stable conduction of large current.

[0026] (2) This invention provides an automated production process for a jump-start module, which couples a gradient composite coating process with a biomimetic microtexture to form a mechanical anchoring structure for the coating inside the microtexture. Directional ultrasonic-assisted electroplating allows the coating to uniformly fill the pits in the microtexture. The gradient coating matches the coefficient of thermal expansion layer by layer, taking into account conductivity, heat resistance and self-healing performance, greatly improving the bonding strength between the coating and the substrate, avoiding the softening and peeling of the coating under thermal shock, and realizing dynamic self-healing of the contact interface. Unlike the defects of traditional single coating that rely only on surface bonding and are prone to high-temperature failure, it cannot solve the problems of weak coating bonding and thermal deformation. It effectively blocks the thermal runaway chain reaction under high current, and extends the service life and stability of the product.

[0027] (3) This invention provides an automated production process for jump-start modules, equipped with a full-process processing procedure and a multi-dimensional core performance online full inspection system, to realize closed-loop feedback control of process parameters. Every process from substrate pretreatment to finished product packaging is controlled, and online detection directly verifies the core performance indicators. Unqualified products are automatically rejected, ensuring the molding accuracy and performance consistency of batch products, and preventing defective products from entering the market. Compared with the existing production line, which lacks full-process accuracy control and core performance full inspection, product performance fluctuations and hidden defects are prone to occur. This invention continuously and stably outputs highly reliable jump-start modules, comprehensively improving the overall quality and market competitiveness of the products. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart illustrating a preferred embodiment of the present invention. Detailed Implementation

[0030] 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.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0032] like Figure 1 As shown, the present invention provides an automated production process for jump-start modules, including the following steps:

[0033] S1. After pre-treatment, the TU2 oxygen-free copper coil is fed into the continuous stamping station at a fixed step distance through a servo feeding mechanism.

[0034] S2. The workpiece is punched, punched, structural reinforcing rib stamped, adaptive floating spring arm preformed, contact patch biomimetic microtexture embossed, and finally bent and cut through a multi-station progressive die to obtain a semi-finished workpiece.

[0035] S3. Deburr the blanking surface of the semi-finished workpiece and level the contact patch working surface.

[0036] S4. Clean the surface of the leveled workpiece to remove oil and oxide layer, and then dry it with hot air.

[0037] S5. The dried workpiece is sent into the segmented electroplating production line. The pulse power supply is used in conjunction with directional ultrasonic stirring to complete the pre-plating of copper, the intermediate layer of nickel-phosphorus alloy, the surface layer of tin-bismuth alloy and chromium-free passivation treatment in sequence, forming a mechanical anchoring structure of the plating layer in the pit of the biomimetic micro-texture.

[0038] S6. Perform online inspection on the electroplated workpieces, remove unqualified products, and obtain finished power-on modules after bending and shaping the terminals of qualified workpieces, sorting and packaging them.

[0039] The following will describe each step in detail.

[0040] In step S1, a suitable substrate is provided for subsequent stamping to ensure the consistency of workpiece forming and the electrical conductivity of the substrate;

[0041] Step S1 selects TU2 oxygen-free copper as the base material, which is the optimal base material for high current conductive components; internal stress generated during the rolling process is eliminated by uncoiling and leveling, and rolling oil stains on the surface of the coil are removed by degreasing, eliminating the negative impact of raw material defects on subsequent stamping and electroplating processes.

[0042] The rolled TU2 oxygen-free copper strip is loaded into an uncoiler and released at a uniform speed. The strip is then leveled by a seven-roll leveler, and the straightness of the strip is controlled within 0.1 mm / m after leveling. The leveled strip is then fed into an ultrasonic degreasing tank, where an alkaline degreasing agent is used to remove the rolling oil stains from the surface. After degreasing, the strip is rinsed with clean water for two stages and dried with hot air. Finally, it is fed into the stamping station at a fixed step distance by a servo feeding mechanism.

[0043] To control the cumulative feeding error in multi-station continuous stamping and ensure forming accuracy, the cumulative error calculation formula is as follows: ;

[0044] In the formula: This represents the cumulative feeding error across multiple workstations, expressed in mm. The number of stations for a multi-station progressive die; This represents the positioning error for a single feeding operation, expressed in mm.

[0045] This process will reduce the positioning error of a single feeding operation. Strictly controlled within ±0.02mm, ensuring the cumulative feeding error of the 16-station progressive die is ≤±0.05mm, fully meeting the precision requirements of one-piece molding.

[0046] In step S2, an adaptive floating bonding structure and a biomimetic microtexture contact interface are constructed through continuous forming using a multi-station progressive die, which increases the effective contact area between the contact patch and the battery terminal, reduces the initial contact resistance, and simultaneously constructs a mechanical anchoring structure for subsequent plating.

[0047] Step S2 is based on the Holm contact resistance formula in the field of electrical contacts. This formula is the fundamental formula for setting up high-current conductive contacts, and is as follows: ;

[0048] In the formula: Total contact resistance, in Ω; The resistivity of the contact material is expressed in Ω·m. The normal force at a single contact point, expressed in N; The Brinell hardness of the contact material is expressed in Pa. This represents the number of effective conductive contact points.

[0049] From the above formula, it can be seen that the total contact resistance is related to the number of effective contact points. Inversely proportional to the normal force at a single contact point It is inversely proportional to the square root;

[0050] This process reduces contact resistance from the fundamental principle through two core structural designs:

[0051] Symmetrical C-shaped adaptive floating spring arm: This design achieves adaptive oscillation of the contact patch through elastic deformation, compensating for shape and position errors caused by deviations in the arc surface of the battery terminal and the clamping angle. It transforms the line contact / partial surface contact of traditional rigid patches into full-working-surface contact, effectively increasing the contact area and significantly enhancing the normal force at a single contact point. ;

[0052] Honeycomb-like biomimetic microtexture array: transforms traditional single planar contact into a composite contact mode of surface contact + thousands of micron-level point contacts, increasing the number of effective contact points within the working surface of a conventionally sized contact patch. Increase by two orders of magnitude, fundamentally reducing total contact resistance. .

[0053] In one specific embodiment, a 12-16 station multi-station progressive die is used to sequentially complete the processes of punching the guide hole, punching the outer shape, punching the hole, pressing the structural reinforcing rib, pre-bending the floating spring arm, micro-textured precision stamping, final bending of the floating spring arm, shaping, and cutting. All processes are completed continuously within the same set of dies without secondary clamping. During the stamping process, dynamic die clearance compensation is completed every two stamping strokes, and the stamping speed is controlled at 60-80 rpm.

[0054] A dynamic compensation mechanism for die clearance is set up to eliminate the accuracy deviation caused by continuous die stamping wear. The compensation amount is calculated using the following formula: ;

[0055] In the formula: This is the mold clearance compensation amount, in mm; This is the wear coefficient for a single stamping operation, expressed in mm / cycle. This refers to the number of stamping strokes.

[0056] This process uses dynamic compensation to control the mold gap fluctuation within ±0.005mm, ensuring batch consistency of microtexture imprinting depth.

[0057] In step S3, burrs on the stamped section are removed to ensure the bonding accuracy of the contact patch and amplify the contact optimization effect of adaptive floating bonding and biomimetic microtexture.

[0058] Among them, a double-sided silicon carbide flexible roller brush is used to remove burrs. The roller brush rotates at high speed to remove micro burrs from the punched section without damaging the micro-texture structure of the contact patch working surface.

[0059] Dual servo diamond leveling rollers are used to cold press and level the contact patch working surface through controllable pressure, eliminating the warping of the working surface caused by stamping internal stress.

[0060] Specifically, the stamped semi-finished products are transferred to the deburring station by a gantry robot. The speed of the double-sided roller brush is controlled at 1200-1800 rpm. During deburring, the workpiece surface is cleaned with 0.6MPa high-pressure cold air. The deburred workpiece is sent to the leveling station. The pressure of the leveling roller is adjusted in real time according to the thickness of the workpiece, with an adjustment range of 5-20MPa. The flatness of the contact surface of the plate-mounting workpiece after leveling is controlled at 0.005-0.02mm / m.

[0061] In step S4, impurities on the workpiece surface and in the microtexture pits are removed to provide a clean interface for subsequent coating growth and ensure the bonding strength between the coating and the substrate. In this process, atmospheric pressure low temperature argon-oxygen mixed plasma cleaning is used to remove debris and oxide layer from the workpiece surface through the physical bombardment of high-energy particles in the plasma.

[0062] The oxygen plasma decomposes oil and other organic pollutants through chemical reactions, achieving a dual physical and chemical cleaning effect. The low-temperature plasma cleaning temperature does not damage the microstructure of the micro-texture.

[0063] Specifically, the leveled workpiece is continuously fed into the plasma cleaning chamber via a chain conveyor mechanism. A 30° inclined directional nozzle is used to directly face the contact patch working surface to ensure that the plasma jet completely enters the microtextured pit. The volume ratio of argon to oxygen is 9:1, the plasma power is 4-6kW, and the cleaning travel speed is 2-3m / min. The cleaned workpiece is immediately sent into a hot air circulating oven and dried at a temperature of 80-100℃.

[0064] In step S5, a gradient composite coating is grown in situ within the biomimetic microtexture pits to form a dual bonding structure of intermolecular bonding and mechanical anchoring. Simultaneously, the gradient coating design meets the triple performance requirements of high conductivity, high heat resistance, and self-healing, forming a complete protective closed loop with the contact structure in S2. This is the core implementation process for achieving synergistic effects in this invention.

[0065] Traditional planar coatings are bonded to the substrate solely by van der Waals forces, resulting in low adhesion and easy softening and detachment under high-current thermal shock.

[0066] This invention utilizes in-situ coating growth within microtextured pits. The coating fills the pits, forming a mechanical interlocking structure, significantly improving coating adhesion. The total adhesion strength is calculated using the following formula: ;

[0067] In the formula: This represents the total bonding strength between the coating and the substrate, expressed in MPa. The van der Waals bond strength between the coating and the substrate, expressed in MPa, is the standard for conventional planar coatings. Only 10-15 MPa; The mechanical interlocking strength between the coating and the microtextured pits is expressed in MPa. The honeycomb pit structure of this invention can... It reaches 30-45 MPa.

[0068] The process employs a gradient structure: a pre-plated copper layer, a nickel-phosphorus alloy intermediate layer, and a tin-bismuth alloy surface layer. The thermal expansion coefficients of each layer are progressively matched, from the copper substrate (17.5 × 10⁻⁶ / ℃) → nickel-phosphorus alloy (13.5 × 10⁻⁶ / ℃) → tin-bismuth alloy (23 × 10⁻⁶ / ℃). This significantly reduces the internal stress of the plating layer under high-current thermal shock, preventing cracking and peeling. Simultaneously, pulsed electroplating combined with directional ultrasonic stirring enhances the plating depth within the micro-textured pits, eliminating bubble retention and the shielding effect of the plating solution, ensuring uniform in-situ growth of the plating layer.

[0069] Specifically, the dried workpiece is fed into a segmented electroplating production line through a special hanger, and then undergoes pre-plating of copper, intermediate layer plating of nickel-phosphorus alloy, surface plating of tin-bismuth alloy and chromium-free passivation treatment in sequence. During the electroplating process, a pulse power supply is used in conjunction with a directional ultrasonic stirring system with a vibration frequency of 40-60kHz. The vibration direction is consistent with the opening direction of the biomimetic micro-textured pits.

[0070] In step S6, full inspection of the core performance indicators of the product is carried out, forming a closed-loop feedback mechanism for process parameters to ensure the consistency and stability of batch product performance;

[0071] Among them, a multi-station online inspection system is adopted to sequentially complete the inspection of micro-texture integrity, high current contact resistance, coating thickness and adhesion, and floating spring arm fatigue strength. All inspection data are uploaded to the PLC control system in real time. The system automatically adjusts process parameters such as stamping pressure, electroplating current density, and leveling pressure according to the fluctuation of the inspection data, forming a closed-loop control of the entire process.

[0072] Specifically, after electroplating, the workpieces pass through four inspection stations in sequence. Defective products are automatically rejected by a robotic arm. Qualified workpieces are transferred to the servo bending station by a six-axis robotic arm to complete the precision bending of the wiring terminals and the pre-forming of the cable crimping groove. The bending angle error is controlled within ±0.3°. Finally, the workpieces are graded, sorted, and vacuum-packed to prevent air oxidation and ensure the stable performance of the products during long-term storage.

[0073] Example 1:

[0074] S1. TU2 oxygen-free copper coil with a thickness of 2.0mm is used. After uncoiling, leveling and degreasing pretreatment, it is fed into the continuous stamping station by a servo feeding mechanism at a fixed length step distance.

[0075] S2. The workpiece is punched, punched, reinforced with ribs, formed by adaptive floating spring arm, imitative micro-texture embossing, and finally bent and cut through a 16-station progressive die to obtain a semi-finished workpiece; the micro-texture pit has a diameter of 40μm and a depth of 10μm, and the floating spring arm has a unidirectional floating stroke of 0.4mm.

[0076] S3. Perform punching and deburring on the semi-finished workpiece, and level the contact patch working surface to make the flatness of the working surface 0.01mm / m.

[0077] S4. Perform plasma cleaning on the leveled workpiece to remove oil and oxide layer, and then dry it with hot air at 90℃.

[0078] S5. The dried workpiece is sent into the segmented electroplating production line. A pulse power supply is used in conjunction with 40kHz directional ultrasonic stirring to sequentially complete the pre-plating of copper, the intermediate layer of nickel-phosphorus alloy, the surface layer of tin-bismuth alloy, and chromium-free passivation. A mechanical anchoring structure for the plating layer is formed in the micro-textured pits. The thickness of the pre-plated copper layer is 4μm, the thickness of the nickel-phosphorus alloy layer is 3μm, and the thickness of the tin-bismuth alloy layer is 9μm.

[0079] S6. Perform online inspection on the electroplated workpieces, remove unqualified products, and obtain the finished power-on module after bending the terminals, sorting and packaging qualified workpieces.

[0080] Example 2:

[0081] This embodiment is basically the same as embodiment 1, except that in step S2, the diameter of the biomimetic microtexture pit is adjusted to 30μm.

[0082] Example 3:

[0083] This embodiment is basically the same as embodiment 1, except that in step S2, the diameter of the biomimetic microtexture pit is adjusted to 50μm.

[0084] Example 4:

[0085] This embodiment is basically the same as embodiment 1, except that in step S2, the diameter of the biomimetic microtexture pit is adjusted to 45μm.

[0086] Example 5:

[0087] This embodiment is basically the same as embodiment 1, except that in step S2, the unidirectional floating stroke of the adaptive floating arm is adjusted to 0.3mm.

[0088] Example 6:

[0089] This embodiment is basically the same as embodiment 1, except that in step S2, the unidirectional floating stroke of the adaptive floating spring arm is adjusted to 0.5mm.

[0090] Example 7:

[0091] This embodiment is basically the same as embodiment 1, except that in step S2, the unidirectional floating stroke of the adaptive floating arm is adjusted to 0.35mm.

[0092] Example 8:

[0093] This embodiment is basically the same as embodiment 1, except that in step S5, the vibration frequency of the directional ultrasonic stirring is adjusted to 50kHz.

[0094] Example 9:

[0095] This embodiment is basically the same as embodiment 1, except that in step S5, the vibration frequency of the directional ultrasonic stirring is adjusted to 60kHz.

[0096] Example 10:

[0097] This embodiment is basically the same as embodiment 1, except that in step S5, the vibration frequency of the directional ultrasonic stirring is adjusted to 45kHz.

[0098] Comparative Example 1:

[0099] This comparative example is basically the same as Example 1, except that in step S2, the biomimetic microtexture imprinting process of the contact patch is cancelled, and the contact patch is a smooth plane.

[0100] Comparative Example 2:

[0101] This comparative example is basically the same as Example 1, except that in step S2, the adaptive floating elastic arm preforming process is cancelled and a traditional rigid contact patch is used.

[0102] Comparative Example 3:

[0103] This comparative example is basically the same as Example 1, except that in step S5, the pre-plating of copper and nickel-phosphorus alloy intermediate layer and directional ultrasonic stirring are cancelled, and only pure tin is plated to 9μm using the traditional process, without a mechanical anchoring structure for the plating.

[0104] Experimental example:

[0105] Experimental objective:

[0106] The differences between the grounding modules prepared in Examples 1-10 and Comparative Examples 1-3 in six core indicators were verified: initial contact resistance, contact resistance after thermal shock, coating bonding strength, effective contact area, critical temperature for thermal runaway, and fatigue performance attenuation rate.

[0107] Experimental methods:

[0108] Contact resistance test: According to the IEC60512-5-1 electronic device connector contact resistance test standard, the initial contact resistance at room temperature was measured by simulating a 1000A high current for emergency starting of a car; the contact resistance was retested after 10 high current thermal shocks.

[0109] Coating adhesion strength test: According to ASTM B571 standard for testing the adhesion strength of metal coatings, the thermal shock method and tape peeling method are used to quantitatively test the adhesion strength between the coating and the substrate.

[0110] Effective contact area test: The actual effective contact area is calculated by three-dimensional laser morphology scanning method according to the ISO14993 standard for measuring the effective contact area of ​​electrical contact surfaces.

[0111] Thermal runaway critical temperature test: According to the IEC60695-2-11 glow wire test standard, the thermal runaway critical temperature of the product is tested (the higher the value, the stronger the resistance to thermal runaway).

[0112] Fatigue resistance decay rate test: According to the ASTM F2067 standard for fatigue life of elastic contact components, the contact resistance decay rate is calculated after 1000 cycles of clamping (the lower the value, the better the fatigue resistance).

[0113] Test environment: temperature 25±1℃, humidity 50±5%RH, each group of samples was measured 3 times and the average value was taken; the data are shown in Table 1.

[0114] Table 1:

[0115] Sample number Initial contact resistance (mΩ) Contact resistance after thermal shock (mΩ) Coating adhesion strength (MPa) Effective contact area (mm²) Critical temperature for thermal runaway (°C) Fatigue performance degradation rate (%) Example 1 0.87 1.02 42.35 89.63 387.42 1.25 Example 2 1.13 1.36 38.72 82.45 365.18 2.47 Example 3 1.08 1.29 39.56 84.71 371.63 2.19 Example 4 0.94 1.11 40.89 87.26 380.54 1.63 Example 5 1.21 1.45 37.84 80.32 358.97 2.86 Example 6 1.17 1.40 38.21 81.59 362.30 2.61 Example 7 1.03 1.22 39.97 85.88 375.79 1.94 Example 8 0.91 1.07 41.62 88.14 383.26 1.48 Example 9 0.96 1.14 40.35 86.57 378.91 1.72 Example 10 0.93 1.09 41.08 87.92 381.75 1.56 Comparative Example 1 3.25 5.78 12.43 26.79 210.36 8.92 Comparative Example 2 3.58 6.21 13.17 23.45 205.81 9.67 Comparative Example 3 2.94 4.83 15.69 31.82 235.74 7.35

[0116] As shown in Table 1:

[0117] Example 1 uses the optimal combination of parameters: biomimetic microtextile pit diameter of 40μm, adaptive floating arm stroke of 0.4mm, and directional ultrasonic stirring frequency of 40kHz.

[0118] At the microscopic level, the honeycomb-like pits enable the coated metal ions to form a dual-strength structure with intermolecular van der Waals forces and mechanical anchoring between the copper substrate and the coated molecules. The coated molecules are deposited densely without gaps, and the nickel-phosphorus alloy intermediate layer molecules form a stable heat-resistant barrier. The adaptive floating structure achieves full microscopic adhesion of the contact interface, and the number of effective conductive contact points and electron transport efficiency reach their peak. The coating bonding strength, thermal runaway resistance and fatigue stability are all optimal, and all performance indicators are significantly better than other groups.

[0119] Examples 2-4 only adjusted the diameter of the biomimetic microtexture pits. The 30μm pits had a small microscopic space, resulting in insufficient metal ion filling and failure to form a complete mechanical anchoring structure. The 50μm pits were prone to molecular stress concentration at the coating edge, and micro-cracks were likely to occur under thermal shock. The 45μm pits did not reach the optimal matching size, and the density of conductive contact points and the microscopic stability of the coating were weaker than those in Example 1, with the overall performance showing a gradient decline.

[0120] Examples 5-7 only changed the stroke of the adaptive floating spring arm. The 0.3mm stroke was insufficient for microscopic compensation, and the presence of molecular-level gaps at the contact interface caused electron transmission to be blocked. The 0.5mm stroke was prone to microscopic slippage of the metal lattice, which accelerated the fatigue of the elastic structure. The 0.35mm stroke did not achieve optimal form and position compensation, and the microscopic tightness of the contact surface decreased. The effective conductive points and the uniformity of the coating force were not as good as in Example 1.

[0121] Examples 8-10 only adjusted the directional ultrasonic stirring frequency. The 50kHz and 60kHz vibrations were too strong and disturbed the directional deposition of metal ions, resulting in loose molecular arrangement and increased micro gaps in the coating. The 45kHz vibration did not achieve uniform ion penetration in the pits, the coating micro-filling was not dense, the mechanical anchoring structure was not intact, and the electron transport efficiency and coating heat resistance stability were inferior to those in Example 1.

[0122] Comparative Example 1 eliminates the biomimetic microtexture imprinting, the contact patch is a smooth plane, the coating and the substrate are only bonded by weak van der Waals forces, there is no micro-mechanical anchoring structure, the coating is prone to thermal shock and peeling off, and the number of effective micro-conductive contact points is greatly reduced, the electron migration resistance increases sharply, and the various performance indicators deteriorate significantly.

[0123] Comparative Example 2 eliminates the adaptive floating spring arm and uses a rigid contact patch, which cannot compensate for the polarity error. The contact interface only has local microscopic adhesion, and there are molecular-level gaps in most areas. The electron transport path is interrupted, the effective contact area is extremely small, and local microscopic heating is severe under high current. The metal lattice distortion and coating ablation rate are the fastest, and the performance is the worst among all groups.

[0124] Comparative Example 3 uses a traditional pure tin plating layer without directional ultrasonic stirring. The lack of gradient plating design leads to a mismatch in the interlayer thermal expansion coefficients, excessive micro-interlayer stress that easily causes cracking, and the absence of ultrasonic assistance results in loose deposition of plating molecules and a lack of mechanical anchoring structure. The plating adhesion is only about one-third of that in Example 1. The pure tin molecules have poor heat resistance and are prone to micro-softening and loss. The core performance is far lower than that of Example 1.

[0125] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An automated production process for a jump-start module, characterized in that, Includes the following steps: S1. After pre-treatment, the TU2 oxygen-free copper coil is fed into the continuous stamping station at a fixed step distance through a servo feeding mechanism. S2. The workpiece is punched, punched, structural reinforcing rib stamped, adaptive floating spring arm preformed, contact patch biomimetic microtexture embossed, and finally bent and cut through a multi-station progressive die to obtain a semi-finished workpiece. S3. Deburr the blanking surface of the semi-finished workpiece and level the contact patch working surface. S4. Clean the surface of the leveled workpiece to remove oil and oxide layer, and then dry it with hot air. S5. The dried workpiece is sent into the segmented electroplating production line. The pulse power supply is used in conjunction with directional ultrasonic stirring to complete the pre-plating of copper, the intermediate layer of nickel-phosphorus alloy, the surface layer of tin-bismuth alloy and chromium-free passivation treatment in sequence, forming a mechanical anchoring structure of the plating layer in the pit of the biomimetic micro-texture. S6. Perform online inspection on the electroplated workpieces, remove unqualified products, and obtain finished power-on modules after bending and shaping the terminals of qualified workpieces, sorting and packaging them.

2. The automated production process for a jump-start module according to claim 1, characterized in that: In S2, the adaptive floating elastic arm is a C-shaped elastic support arm symmetrically arranged on both sides of the contact patch, and is integrally stamped with the contact patch; the biomimetic microtexture is a honeycomb-shaped micron-level pit array embossed on the working surface of the contact patch.

3. The automated production process for a jump-start module according to claim 2, characterized in that: The honeycomb-like micron-sized pits have a diameter of 30-50 μm, a depth of 8-12 μm, and a spacing of 60-80 μm between adjacent pits.

4. The automated production process for a jump-start module according to claim 2, characterized in that: In S2, the unidirectional floating stroke of the adaptive floating arm is 0.3-0.5mm, the rebound amount is 0.01-0.05mm, and the arc transition radius at the C-shaped bend is 1.2-1.5mm.

5. The automated production process for a jump-start module according to claim 1, characterized in that: In S2, the multi-station progressive die has 12-16 stations, and dynamic compensation of the die clearance is completed every 2 stamping strokes during the stamping process. The stamping speed is 60-80 rpm.

6. The automated production process for a jump-start module according to claim 1, characterized in that: In S3, the flatness of the contact patch working surface after leveling is 0.005-0.02 mm / m.

7. The automated production process for a jump-start module according to claim 1, characterized in that: In S5, the thickness of the pre-plated copper layer is 3-5 μm, the thickness of the nickel-phosphorus alloy intermediate layer is 2-4 μm, and the thickness of the tin-bismuth alloy surface layer is 8-10 μm.

8. The automated production process for a jump-start module according to claim 1, characterized in that: In step S5, the vibration frequency of the directional ultrasonic stirring is 40-60kHz, and the vibration direction is consistent with the opening direction of the biomimetic microtexture pit.

9. The automated production process for a jump-start module according to claim 1, characterized in that: In S5, the pre-plated copper is pre-plated using pulse electroplating with a current density of 2-3 A / dm²; the nickel-phosphorus alloy intermediate layer is plated using DC pulse composite electroplating. The bismuth content in the coating of the tin-bismuth alloy is 3-5 wt%.

10. The automated production process for a jump-start module according to claim 1, characterized in that: In S6, the online detection includes microtexture integrity detection, high current contact resistance detection, coating thickness and adhesion detection, and floating spring arm fatigue strength detection.

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