Vertical continuous copper electroplating device and electroplating method

Abstract

The invention provides a vertical continuous copper electroplating device, and relates to the field of printed circuit board production, the vertical continuous copper electroplating device comprises a pretreatment tank body, an electroplating tank body, an anode assembly, an electroplating cathode and a cathode driving mechanism, the pretreatment tank body is arranged on one side of the electroplating tank body; the anode assembly and the electroplating cathode are arranged in the electroplating bath body, the anode assembly is composed of two sets of electroplating anodes, the electroplating cathode is arranged between the two sets of electroplating anodes, and the electroplating cathode is connected with a cathode driving mechanism arranged on the upper side of the electroplating bath body through a connecting mechanism. The device combines the advantages of the soluble anode and the insoluble anode, is used for preparing the printed circuit board, and can effectively avoid the problems of low electroplating efficiency, non-uniform electroplating and the like in the preparation process of the printed circuit board.

Description

Technical Field

[0001] The invention relates to the technical field of printed circuit production, and in particular to a vertical continuous copper electroplating device and an electroplating method. Background Art

[0002] With the advancement of electronic production technology, the production process of printed circuits is also constantly improving; currently, improving the electroplating quality of printed circuit boards can be started from the optimization of pre-treatment processes, control of electroplating solution parameters, improvement of electroplating equipment, and monitoring of the electroplating process. Among them, the improvement of electroplating cathodes and anodes is a commonly used method in the prior art. In the vertical continuous electroplating copper tank, the anode mainly includes two types: one is the traditional soluble anode-phosphorus copper anode, that is, a small amount of phosphorus is added to the copper anode to form a phosphorus copper anode, and the other is an insoluble anode. As a soluble anode, during the electroplating process, phosphorus copper dissolves into divalent copper ions (Cu 2+ ), thereby maintaining the stability of the copper ion concentration in the electroplating solution; at the same time, a black anodic film, namely copper phosphide film, is formed on the surface of the phosphor copper anode, which can catalyze the copper ions (Cu + ) is oxidized into divalent copper ions, reducing the accumulation of cuprous ions in the plating solution. The presence of the phosphorus film can also make the anode dissolve more evenly, reduce the shedding of copper powder, and thus reduce the amount of anode mud. However, the electroplating time of phosphor copper anode is long, and there are the following problems: (1) Although the amount of anode mud can be reduced, anode mud is still generated, resulting in the need to use the phosphor copper anode with an anode filter bag; (2) During the electroplating process, the phosphor copper anode consumes electroplating additives and chloride ions to a certain extent, increasing the instability of the solution; (3) The phosphor copper anode needs to be replenished periodically and the tank needs to be dragged, affecting production efficiency; (4) As the use time increases, the dissolution of copper causes the shape and specific surface area of ​​the anode to change, affecting the uniformity of electroplating; (5) Due to the presence of free phosphorus in the plating solution, it (i.e., free phosphorus) is deposited in the copper plating layer, affecting the ductility of the copper plating layer. Insoluble anodes, including various anode titanium meshes, platinum titanium meshes, nail molybdenum iridium meshes, etc., have the following advantages over traditional phosphor copper anodes: (1) The geometric dimensions and area of ​​the anode remain unchanged, the current distribution is uniform, and the electroplating thickness is uniform; (2) There is no need to clean and replenish the anode, less maintenance work and high production efficiency; (3) Impurities will not be introduced to contaminate the electroplating solution; (4) The precious metal coated on the surface will have a strong catalytic effect on the regeneration of electroplating additives; (5) The electroplating service life is long and the tolerable current density is high. However, insoluble anodes also have the following disadvantages: (1) Copper oxide powder needs to be replenished in time to ensure the stability of the copper ion content in the electroplating solution; (2) Oxygen will be generated during electroplating, causing a certain degree of decomposition of the additive; (3) The addition of oxidizing electrodes reduces the current efficiency. Summary of the invention

[0003] In view of the problems existing in the above prior art, the purpose of the present invention is to provide a vertical continuous copper electroplating device, which combines the advantages of soluble anodes and insoluble anodes and rearranges the anodes. It can not only provide divalent copper ions during the electroplating process and ensure the stability of the copper ion content during electroplating, but also avoid the loss of additives caused by the elemental oxygen generated during the electroplating process of the insoluble anode, thereby improving the electroplating efficiency and effect.

[0004] Another object of the present invention is to provide a method for vertically and continuously electroplating copper, using the above-mentioned device for electroplating.

[0005] The purpose of the present invention is achieved through the following technical solutions: A vertical continuous copper electroplating device comprises a pretreatment tank, an electroplating tank, an anode assembly, an electroplating cathode and a cathode driving mechanism. The pretreatment tank is arranged on one side of the electroplating tank and is used for pretreatment of the electroplating process; the anode assembly and the electroplating cathode are arranged in the electroplating tank and the anode assembly consists of two groups of electroplating anodes, the electroplating cathode is arranged between the two groups of electroplating anodes and is connected to the cathode driving mechanism arranged on the upper side of the electroplating tank through a connecting mechanism.

[0006] Based on the further optimization of the above scheme, the electroplating anode is formed by alternating phosphor copper anode and insoluble anode, and the arrangement includes the following two ways: Method 1: The electroplating anodes on both sides of the electroplating tank are made of "X1 phosphor copper anode-Y1 insoluble anode-...-X n Phosphorus copper anode-Y n Insoluble anode"; Method 2: The electroplating anode on one side of the electroplating tank is "X1 phosphor copper anode-Y1 insoluble anode-...-X n Phosphorus copper anode-Y n Insoluble anode", the electroplating anode on the other side is "Y1 insoluble anode - X1 phosphor copper anode - ... -Y n Insoluble Anode-X n Phosphor copper anode"; Where n is not less than 1 and when n=1, "X1 phosphor copper anode-Y1 insoluble anode-...-X n Phosphorus copper anode-Y n The "insoluble anode" is expressed as "X1 phosphor copper anode-Y1 insoluble anode"; the phosphor copper anode and the insoluble anode in the same set of electroplating anodes are electrically connected to each other.

[0007] Based on further optimization of the above scheme, the electroplating anodes on both sides of the electroplating tank (i.e., the electroplating anodes in which phosphor copper anodes and insoluble anodes are arranged alternately) are respectively wrapped with diaphragms, and the material used for the diaphragm is any one of polytetrafluoroethylene (PTFE) material, polypropylene (PP) material, glass fiber, aromatic polyamide fiber material, polyethylene terephthalate (PET) material, and polytetrafluoroethylene (PTFE) material + polypropylene (PP) material.

[0008] Based on further optimization of the above scheme, the phosphor copper anode and the insoluble anode include an anode conductive support, an anode insulating layer and an anode plate, the anode conductive support is provided with an anode insulating layer in the inner circle, and the anode plate is provided in the inner circle of the anode insulating layer, and the anode plate and the anode conductive support are electrically connected; the anode plate selects phosphor copper material or insoluble material according to the type of electroplating anode, wherein the insoluble material adopts an insoluble titanium mesh or titanium plate; the electroplating cathode includes a cathode conductive support, a cathode insulating layer and an electroplating plate, the cathode conductive support is provided with a cathode insulating layer in the inner circle, and the electroplating plate is provided in the inner circle of the cathode insulating layer, and the electroplating plate and the cathode conductive support are electrically connected.

[0009] A vertical continuous copper electroplating method, using the above electroplating device, comprises: Step S1, pre-treatment: using a pre-treatment tank to sequentially pre-treat the electroplating cathode to be electroplated; Step S2, electroplating installation: hang the pre-treated electroplating cathode on the cathode driving mechanism through the connecting mechanism, and ensure that it is reliably connected to the cathode output end of the power supply; then, connect the power supply anode to the electroplating anode set in the electroplating tank body respectively; Step S3, electroplating treatment: add electroplating solution into the electroplating tank, start the power supply device, and start the electroplating operation; during the electroplating process, the cathode driving mechanism drives the electroplating cathode to move along the length direction of the electroplating tank (i.e., the arrangement direction of the electroplating anode), and at the same time drives the electroplating cathode to swing left and right (the cathode plate swings left and right to increase the convection in the electroplating tank and ensure the uniformity of electroplating), until the electroplating is completed; Step S4, post-processing: taking out the electroplating cathode from the electroplating tank after the electroplating is completed, disassembling the electroplating plate, and sequentially performing water washing, purification, drying and other processing steps.

[0010] Based on further optimization of the above scheme, the pre-treatment includes steps such as degreasing, slight etching, pickling, and water washing.

[0011] Based on the further optimization of the above scheme, the driving electroplating cathode to swing left and right is carried out according to the sine wave law to produce a stable convection effect, specifically:

[0012] Where: x(t) Indicates the location of the electroplating cathode; A Indicates the shaking amplitude; f Indicates the shaking frequency; t Indicates the plating time; Among them, the shaking amplitude A With shaking frequency f Controlled by PID controller:

[0013] Where: K p , K i , K d Respectively represent the proportional, integral, and differential coefficients; e(t) Represents the difference between the predicted value and the actual value, that is, the error value; u(t) Indicates the control output value, i.e. the motor swing position; Since the left and right swing is to avoid the change of the electrolyte copper ion concentration and current density at the next moment, which will lead to the problem of uneven electroplating, the predicted values ​​of the electrolyte copper ion concentration and current density at the next moment are obtained by the following formula: Copper ion concentration: The convection-diffusion equation describing the change of copper ion concentration C is:

[0014] Where: D represents the diffusion coefficient, U represents the flow velocity vector; If U=( U x , U y ),but: Convection term discretization for:

[0015] Diffusion term discretization for:

[0016] Where: Represents spatial grid coordinate points (i,j) , the copper ion concentration at the mth moment; represents the spatial step length in the x direction, Indicates the spatial step length in the y direction; Finally, the copper ion concentration at the next moment is obtained :

[0017] Where: represents the time step; Current density:

[0018]

[0019] Where: denote the transfer coefficients of the anode and cathode, respectively; J 0 represents the exchange current density; R represents the gas constant; T Indicates temperature; F represents the Faraday constant; E(t) Indicates the applied voltage; E eq represents the equilibrium potential; n represents the number of electron transfers; C b (t) Indicates the bulk solution concentration; C s (t) Indicates the electrode surface concentration; The actual value of copper ion concentration and current density is obtained through real-time monitoring by IoT sensors evenly set in the electroplating tank, where:

[0020] Where: I i Indicates i The current at each monitoring point, S i Indicates i The effective area of ​​the electrode at each monitoring point.

[0021] Based on the further optimization of the above scheme, the shaking amplitude A With shaking frequency f It is also optimized through optimization algorithms, specifically: First, the shaking amplitude A With shaking frequency f Encoded as chromosomes: Right now ; And define the constraints: , ; Then, define the fitness function Q(A,f) , used to measure the current density uniformity and copper ion concentration fluctuation:

[0022] Where: Ci Indicates i The copper ion concentration at each sample point is M Indicates existence M The copper ion concentration is collected at the following points: J i Indicates i The current density at each sample point is N Indicates existence N The current density collection points; w 1. w 2 represent the weight coefficients of current density and copper ion concentration respectively; Randomly generate L chromosomes, each containing a shaking amplitude A With shaking frequency f :

[0023] Afterwards, high-quality individuals are selected by fitness value to enter the next generation. i The probability of being selected is:

[0024] For the selected parent individuals [ A 1, f 1]、[ A 2, f 2] Gene exchange to generate offspring [ A’ , f’ ]:

[0025] Where: represents the cross-distribution index ( Usually follows a uniform distribution in the interval (0,1)); Then randomly perturb the offspring genes (for the shaking amplitude A or shaking frequency f ), generate mutation values x’ :

[0026] Where: Indicates variable asynchronous length.

[0027] Where: v It follows a uniform distribution in the interval (0,1); represents the variation distribution index (usually 20); Merge the parent generation and the offspring (including offspring after crossover and mutation), and select the first L individuals according to fitness to form a new population; The maximum number of iterations and the fitness convergence value are preset. If the maximum number of iterations is reached or the fitness change of X consecutive generations is less than the fitness convergence value, the iteration is stopped to obtain the optimal parameters.

[0028] The following are the technical effects of the method of the present invention: The present invention forms an anode distribution by alternately arranging phosphor copper anodes and insoluble anodes, which can not only provide copper ions through the phosphor copper anodes during the electroplating process to ensure the copper ion content in the electroplating solution, but also can reduce the consumption of electroplating additives by cuprous ions and oxygen content through the reaction of cuprous ions generated by the phosphor copper anodes and elemental oxygen generated by the insoluble anodes, thereby giving full play to the respective advantages of the phosphor copper anodes and insoluble anodes. At the same time, the present invention realizes the left and right swing of the cathode during the electroplating process through an intelligent algorithm, effectively increases the convection in the electroplating tank, cooperates with the wrapping of the electroplating anode, ensures the uniformity of the copper ion concentration and the current density, and then ensures the uniformity of electroplating, avoids defects or unevenness in the cathode deposition process, and affects the final performance of the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of a vertical continuous electroplating device in an embodiment of the present invention.

[0030] Figure 2 Schematic diagram of the structure of the electroplating anode and the electroplating cathode in an embodiment of the present invention; Figure 2 (a) represents phosphor copper anode, Figure 2 (b) represents an insoluble anode, Figure 2 (c) represents the electroplating cathode.

[0031] Among them, 1. electroplating anode; 11. anode conductive bracket; 12. insulating layer; 13. anode plate; 2. electroplating cathode; 21. cathode conductive bracket; 22. cathode insulating layer; 23. electroplating plate; 3. cathode driving mechanism; 4. connecting mechanism; 5. pre-treatment tank body; 6. electroplating tank body. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0033] Embodiment 1: A vertical continuous copper electroplating device, see Figure 1As shown, it includes a pretreatment tank body 5, an electroplating tank body 6, an anode assembly, an electroplating cathode 2 and a cathode driving mechanism 3, the pretreatment tank body 5 is arranged on one side of the electroplating tank body 6 (in this embodiment, the pretreatment tank body 5 is located on the left side of the electroplating tank body 6, and the number of pretreatment tank bodies 5 is specifically set according to the pretreatment means, which can be understood by those skilled in the art; for example, in this embodiment, the pretreatment includes degreasing, pickling, and water washing, so 3 pretreatment tank bodies 5 are set; if the pretreatment includes degreasing, slight etching, pickling, and water washing, then 4 pretreatment tank bodies 5 are set), which is used for pretreatment of the electroplating process; the anode assembly and the electroplating cathode 2 are arranged in the electroplating tank body 6 and the anode assembly is composed of two groups of electroplating anodes 1, the electroplating cathode 2 is arranged between the two groups of electroplating anodes 1 and the electroplating cathode 2 is connected to the cathode driving mechanism 3 arranged on the upper side of the electroplating tank body 6 through a connecting mechanism 4 (as shown in FIG. Figure 1 As shown, the electroplating cathode 2 is mounted on the conveyor belt of the cathode driving mechanism 3 by means of the connecting mechanism 4; at the same time, the cathode driving mechanism 3 is also configured to control the electroplating cathode 2 to perform the following steps: Figure 2 The drive motor shown shakes back and forth, and the drive motor moves on the conveyor belt synchronously with the electroplating cathode 2).

[0034] The electroplating anode 1 is formed by alternating phosphor copper anodes and insoluble anodes, and the arrangement methods include the following two: Method 1: electroplating both sides of the tank body 6 (i.e. Figure 1 The electroplating anode 1 of the front and rear sides (shown in the figure) adopts "X1 phosphor copper anode-Y1 insoluble anode-...-X n Phosphorus copper anode-Y n Insoluble anode"; Method 2: The electroplating anode 1 on one side of the electroplating tank 6 is "X1 phosphor copper anode-Y1 insoluble anode-...-X n Phosphorus copper anode-Y n Insoluble anode", the electroplating anode 1 on the other side is "Y1 insoluble anode - X1 phosphor copper anode - ... -Y n Insoluble Anode-X n Phosphor copper anode"; Where n is not less than 1 and when n=1, "X1 phosphor copper anode-Y1 insoluble anode-...-X n Phosphorus copper anode-Y n The "insoluble anode" is expressed as "X1 phosphor copper anode-Y1 insoluble anode"; the phosphor copper anode and the insoluble anode in the same group of electroplating anodes 1 are electrically connected to each other.

[0035] In addition, the phosphor copper anode and the insoluble anode both include an anode conductive support 11, an anode insulating layer 12 and an anode plate 13. The anode conductive support 11 (such as Figure 2As shown, in this embodiment, the anode conductive support 11 is a rectangular outer frame) and the inner circle of the anode insulating layer 12 is provided with an anode plate 13, and the anode plate 13 is electrically connected to the anode conductive support 11 (such as Figure 2 As shown, in this embodiment, a conductive rod is respectively arranged at the upper and lower ends of the anode conductive support 11, and the conductive rod penetrates the corresponding anode insulating layer 12 and is connected to the upper and lower surfaces of the anode plate 13, and the material of the conductive rod is consistent with the material of the anode conductive support 11); the anode plate 13 selects phosphor copper material or insoluble material according to the type of electroplating anode, wherein the insoluble material adopts insoluble titanium mesh or titanium plate. At the same time, the electroplating anodes 1 on both sides of the electroplating tank 6 (i.e., the electroplating anodes 1 in which phosphor copper anodes and insoluble anodes are alternately arranged) are respectively wrapped with diaphragms, and the material used for the diaphragm is any one of polytetrafluoroethylene (PTFE) material, polypropylene (Polypropylene, PP) material, glass fiber, aromatic polyamide fiber material, polyethylene terephthalate (PET) material, polytetrafluoroethylene (PTFE) material + polypropylene (Polypropylene, PP) material (preferably polytetrafluoroethylene material + polypropylene material, wrapped by the diaphragm to prevent oxygen from escaping to the cathode as bubbles and causing deposition defects at the cathode).

[0036] The electroplating cathode 2 includes a cathode conductive support 21, a cathode insulating layer 22 and an electroplating plate 23. The cathode conductive support 21 (such as Figure 2 As shown, in this embodiment, the cathode conductive support 21 is a rectangular outer frame) and the inner circle of the cathode insulating layer 22 is provided with a cathode insulating layer 22 and the inner circle of the cathode insulating layer 22 is provided with a plating plate 23, and the plating plate 23 is electrically connected to the cathode conductive support 21 (such as Figure 2 As shown, in this embodiment, a conductive rod is respectively provided at the upper and lower ends of the cathode conductive bracket 21, the conductive rod passes through the corresponding cathode insulating layer 22 and is connected to the upper and lower surfaces of the electroplating plate 23, and the material of the conductive rod is consistent with that of the cathode conductive bracket 21).

[0037] The anode conductive support 11 and the cathode conductive support 21, the anode insulating layer 12 and the cathode insulating layer 22 are all made of the same material. The structural design of the electroplating anode 1 (i.e., the alternating arrangement of phosphor copper anodes and insoluble anodes) can effectively change the area of ​​the anode to adapt to different electroplating devices and environments.

[0038] Embodiment 2: A method for vertically and continuously electroplating copper, using the electroplating device as described in Example 1, comprising: Step S1, pretreatment: pretreatment the electroplating cathode to be electroplated in turn by using a pretreatment tank; the pretreatment includes steps such as degreasing, slight etching, pickling, and water washing (degreasing, i.e., using organic solvents, alkaline solutions or surfactants to remove oil, grease and other organic pollutants on the surface of the circuit board. Alkaline degreasing agents include sodium hydroxide, sodium carbonate, sodium phosphate, etc. Slight etching, i.e., slightly etching the surface of the circuit board by chemical corrosion to remove the oxide layer and impurities on the surface and increase the surface roughness. Etching agents include sodium sulfate, concentrated sulfuric acid and other solutions; pickling, immersing the circuit board in a dilute sulfuric acid or hydrochloric acid solution for a short period of time, generally 30 to 50 seconds, to remove the metal oxide of the circuit board and activate its surface; water washing, washing the surface of the circuit board with deionized water or distilled water for multiple times, generally not less than 2 times, to remove residual chemical substances).

[0039] Step S2, electroplating installation: hang the pre-treated electroplating cathode 2 on the cathode driving mechanism 3 through the connecting mechanism 4, and ensure that it is reliably connected to the cathode output end of the power supply (external power supply); then, connect the power supply anode to the electroplating anode 1 set in the electroplating tank 6 respectively; Step S3, electroplating treatment: add electroplating solution (common electroplating solution can be used) into the electroplating tank 6, start the power supply device, and start the electroplating operation; during the electroplating process, the cathode driving mechanism 3 (i.e., the conveyor belt) drives the electroplating cathode 2 to move along the length direction of the electroplating tank 6 (i.e., the arrangement direction of the electroplating anode 1), and at the same time (i.e., the driving motor of the cathode driving mechanism 3) drives the electroplating cathode 2 to swing left and right (i.e., Figure 1 The cathode plate swings left and right to increase the convection in the electroplating tank and ensure the uniformity of electroplating. During this process, the drive motor and the electroplating cathode 2 move synchronously along the length direction of the electroplating tank 6 until the electroplating is completed (during the electroplating process, the temperature of the electroplating solution is generally maintained at 20-30°C); The electroplating cathode is driven to swing left and right according to the sine wave law to produce a stable convection effect, specifically:

[0040] Where: x(t) Indicates the location of the electroplating cathode; A Indicates the shaking amplitude; f Indicates the shaking frequency; t Indicates the plating time; Among them, the shaking amplitude A With shaking frequency f Controlled by PID controller:

[0041] Where: K p ,K i , K d Respectively represent the proportional, integral, and differential coefficients; e(t) Represents the difference between the predicted value and the actual value, that is, the error value; u(t) Indicates the control output value, i.e. the motor swing position; Since the left and right swing is to avoid the sudden change of the electrolyte copper ion concentration and current density at the next moment, which will lead to the problem of uneven electroplating, the predicted values ​​of the electrolyte copper ion concentration and current density at the next moment are obtained by the following formula: Copper ion concentration: The convection-diffusion equation describing the change of copper ion concentration C is:

[0042] Where: D represents the diffusion coefficient, U represents the flow velocity vector; If U=( U x , U y ),but: Convection term discretization for:

[0043] Diffusion term discretization for:

[0044] Where: Represents spatial grid coordinate points (i,j) , the copper ion concentration at the mth moment; represents the spatial step length in the x direction, Indicates the spatial step length in the y direction (the spatial step length is set according to actual conditions); Finally, the copper ion concentration at the next moment is obtained :

[0045] Where: Indicates the time step (the time step is set according to the actual situation); Current density:

[0046]

[0047] Where: denote the transfer coefficients of the anode and cathode, respectively; J 0 represents the exchange current density; Rrepresents the gas constant; T Indicates temperature; F represents the Faraday constant; E(t) Indicates the applied voltage; E eq represents the equilibrium potential; n represents the number of electron transfers; C b (t) Indicates the bulk solution concentration; C s (t) Indicates the electrode surface concentration; The actual value of copper ion concentration and current density is obtained through real-time monitoring by IoT sensors evenly set in the electroplating tank, where:

[0048] Where: I i Indicates i The current at each monitoring point, S i Indicates i The effective area of ​​the electrode at each monitoring point.

[0049] In addition, the shaking amplitude A With shaking frequency f Optimization is also performed to further avoid sudden changes in copper ion concentration and current density, specifically: First, the shaking amplitude A With shaking frequency f Encoded as chromosomes: Right now ; And define the constraints: , ; Then, define the fitness function Q(A,f) , used to measure the current density uniformity and copper ion concentration fluctuation:

[0050] Where: C i Indicates i The copper ion concentration at each sample point is M Indicates existence M The copper ion concentration is collected at the following points: J i Indicates i The current density at each sample point is N Indicates existence N The current density collection points; w 1. w2 represent the weight coefficients of current density and copper ion concentration respectively; Randomly generate L chromosomes, each containing a shaking amplitude A With shaking frequency f :

[0051] Afterwards, high-quality individuals are selected by fitness value to enter the next generation. i The probability of being selected is:

[0052] For the selected parent individuals [ A 1, f 1]、[ A 2, f 2] Gene exchange to generate offspring [ A’ , f’ ]:

[0053] Where: represents the cross-distribution index ( Usually follows a uniform distribution in the interval (0,1)); Then randomly perturb the offspring genes (for the shaking amplitude A or shaking frequency f ), generate mutation values x’ :

[0054] Where: Indicates variable asynchronous length.

[0055] Where: v It follows a uniform distribution in the interval (0,1); represents the variation distribution index (usually 20); Merge the parent generation and the offspring (including offspring after crossover and mutation), and select the first L individuals according to fitness to form a new population; The maximum number of iterations (for example, 50) and the fitness convergence value are preset (the convergence value is set according to the actual situation). If the maximum number of iterations is reached or the fitness change of X consecutive generations is less than the fitness convergence value, the iteration is stopped to obtain the optimal parameters.

[0056] Step S4, post-treatment: the electroplating cathode 2 after electroplating is taken out from the electroplating tank 6, and the electroplating plate 23 is disassembled, and the water washing, purification, drying and other treatment steps are carried out in sequence (water washing, i.e., removing the electroplating solution remaining on the surface and in the holes of the electroplating plate 23 by deionized water or distilled water; purification, immersing the electroplating plate 23 in a purifying agent such as chromate or phosphate to form a purification film to improve corrosion resistance and oxidation resistance; drying, i.e., drying the electroplating plate 23 in an oven at a temperature of 35 to 40°C to remove moisture on its surface).

Claims

1. A vertical continuous copper electroplating device, characterized in that: It includes a pre-treatment tank body, an electroplating tank body, an anode assembly, an electroplating cathode and a cathode driving mechanism. The pre-treatment tank body is arranged on one side of the electroplating tank body; the anode assembly and the electroplating cathode are arranged in the electroplating tank body and the anode assembly consists of two groups of electroplating anodes, the electroplating cathode is arranged between the two groups of electroplating anodes and the electroplating cathode is connected to the cathode driving mechanism arranged on the upper side of the electroplating tank body through a connecting mechanism.

2. A vertical continuous copper electroplating device according to claim 1, characterized in that: The electroplating anode is formed by alternating arrangement of phosphor copper anode and insoluble anode, and the arrangement includes the following two ways: Method 1: The electroplating anodes on both sides of the electroplating tank are made of "X1 phosphor copper anode-Y1 insoluble anode-...-X n Phosphorus copper anode-Y n Insoluble anode"; Method 2: The electroplating anode on one side of the electroplating tank is "X1 phosphor copper anode-Y1 insoluble anode-...-X n Phosphorus copper anode-Y n Insoluble anode", the electroplating anode on the other side is "Y1 insoluble anode - X1 phosphor copper anode - ... -Y n Insoluble Anode-X n Phosphor copper anode"; Where n is not less than 1 and when n=1, "X1 phosphor copper anode-Y1 insoluble anode-...-X n Phosphorus copper anode-Y n The "insoluble anode" is expressed as "X1 phosphor copper anode-Y1 insoluble anode"; the phosphor copper anode and the insoluble anode in the same set of electroplating anodes are electrically connected to each other.

3. The vertical continuous copper electroplating device according to claim 1 or 2, characterized in that: The electroplating anodes on both sides of the electroplating tank are respectively wrapped with diaphragms, and the material used for the diaphragm is any one of polytetrafluoroethylene material, polypropylene material, glass fiber, aromatic polyamide fiber material, polyethylene terephthalate material, and polytetrafluoroethylene material + polypropylene material.

4. A vertical continuous copper electroplating device according to claim 1 or 2, characterized in that: The phosphor copper anode and the insoluble anode include an anode conductive support, an anode insulating layer and an anode plate. The inner circle of the anode conductive support is provided with an anode insulating layer, and the inner circle of the anode insulating layer is provided with an anode plate, and the anode plate and the anode conductive support are electrically connected; the anode plate selects phosphor copper material or insoluble material according to the type of electroplating anode, wherein the insoluble material adopts an insoluble titanium mesh or titanium plate; the electroplating cathode includes a cathode conductive support, a cathode insulating layer and an electroplating plate. The inner circle of the cathode conductive support is provided with a cathode insulating layer, and the inner circle of the cathode insulating layer is provided with an electroplating plate, and the electroplating plate and the cathode conductive support are electrically connected.

5. An electroplating method using a vertical continuous copper electroplating device as claimed in any one of claims 1 to 4, characterized in that: include: Step S1, pre-treatment: using a pre-treatment tank to sequentially pre-treat the electroplating cathode to be electroplated; Step S2, electroplating installation: hang the pre-treated electroplating cathode on the cathode driving mechanism through the connecting mechanism, and ensure that it is reliably connected to the cathode output end of the power supply; then, connect the power supply anode to the electroplating anode set in the electroplating tank body respectively; Step S3, electroplating treatment: adding electroplating solution into the electroplating tank, starting the power supply device, and starting the electroplating operation; during the electroplating process, the electroplating cathode is driven by the cathode driving mechanism to move along the length direction of the electroplating tank, and at the same time, the electroplating cathode is driven to swing left and right until the electroplating is completed; Step S4, post-processing: taking out the electroplating cathode from the electroplating tank after the electroplating is completed, disassembling the electroplating plate, and performing water washing, purification, and drying treatment steps in sequence.

6. The electroplating method of a vertical continuous copper electroplating device according to claim 5, characterized in that: The driving of the electroplating cathode to swing left and right is performed according to the sine wave law to produce a stable convection effect, specifically: Where: x(t) Indicates the location of the electroplating cathode; A Indicates the shaking amplitude; f Indicates the shaking frequency; t Indicates the plating time; Among them, the shaking amplitude A With shaking frequency f Controlled by PID controller: Where: K p , K i , K d Respectively represent the proportional, integral, and differential coefficients; e(t) Represents the difference between the predicted value and the actual value, that is, the error value; u(t) Indicates the control output value, i.e. the motor swing position; The predicted values ​​of the electrolyte copper ion concentration and current density at the next moment are obtained by the following formula: Copper ion concentration: The convection-diffusion equation describing the change of copper ion concentration C is: Where: D represents the diffusion coefficient, U represents the flow velocity vector; If U=( U x , U y ),but: Convection term discretization for: Diffusion term discretization for: Where: Represents spatial grid coordinate points (i,j) , the copper ion concentration at the mth moment; represents the spatial step length in the x direction, Indicates the spatial step length in the y direction; Finally, the copper ion concentration at the next moment is obtained : Where: represents the time step; Current density at the next moment: Where: denote the transfer coefficients of the anode and cathode, respectively; J 0 represents the exchange current density; R represents the gas constant; T Indicates temperature; F represents the Faraday constant; E(t) Indicates the applied voltage; E eq represents the equilibrium potential; n represents the number of electron transfers; C b (t) Indicates the bulk solution concentration; C s (t) Indicates the electrode surface concentration; The actual value of copper ion concentration and current density is obtained through real-time monitoring by IoT sensors evenly set in the electroplating tank, where: Where: I i Indicates i The current at each monitoring point, S i Indicates i The effective area of ​​the electrode at each monitoring point.

7. The electroplating method of a vertical continuous copper electroplating device according to claim 6, characterized in that: The shaking amplitude A With shaking frequency f It is also optimized through optimization algorithms, specifically: First, the shaking amplitude A With shaking frequency f Encoded as chromosomes: Right now ; And define the constraints: , ; Then, define the fitness function Q(A,f) , used to measure the current density uniformity and copper ion concentration fluctuation: Where: C i Indicates i The copper ion concentration at each sample point is M Indicates existence M The copper ion concentration is collected at the following points: J i Indicates i The current density at each sample point is N Indicates existence N The current density collection points; w 1. w 2 represent the weight coefficients of current density and copper ion concentration respectively; Randomly generate L chromosomes, each containing a shaking amplitude A With shaking frequency f : Afterwards, high-quality individuals are selected by fitness value to enter the next generation. i The probability of being selected is: For the selected parent individuals [ A 1, f 1]、[ A 2, f 2] Gene exchange to generate offspring [ A’ , f’ ]: Where: represents the cross-distribution index; Then randomly perturb the offspring genes to generate mutation values x’ : Where: Indicates variable asynchronous length. Where: v It follows a uniform distribution in the interval (0,1); represents the variation distribution index; Merge the parent generation with the offspring generation, and select the first L individuals according to fitness ranking to form a new population; The maximum number of iterations and the fitness convergence value are preset. If the maximum number of iterations is reached or the fitness change of consecutive X generations is less than the fitness convergence value, the iteration is stopped to obtain the optimal parameters.

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