A trivalent iron electroplating concentration adjustment device and pulse copper plating method thereof

Abstract

The present invention relates to the field of electroplating, and in particular to a device for adjusting the electroplating concentration of trivalent iron and a pulse copper plating method thereof, comprising a pump barrel and a driving mechanism, wherein a cavity is provided in the pump barrel, a screw rod parallel to the axis of the pump barrel is provided in the cavity, a piston is also slidably connected in the pump barrel, the piston is threadedly connected to the screw rod, and the piston is also provided with a valve core mechanism; the adjusting device is also provided with a rotary joint and a one-way valve joint, the screw rod is a hollow tube structure, one end of which is connected to the rotary joint, and the other end passes through the pump barrel and is connected to the driving mechanism, the screw rod is also provided with an extraction hole and a stirring rod, the extraction hole is connected to the rotary joint, and the driving mechanism drives the screw rod to rotate and drive the piston to reciprocate in the cavity of the pump barrel. The present invention can control the Fe3+ concentration in the electroplating solution to be stable within a set range, and can accurately push the electroplating solution into the copper dissolving tank, maintain the ion concentration balance of the electroplating solution, meet the continuous production of the electroplating production line, and improve production efficiency.

Description

Technical Field

[0001] The invention relates to the field of electroplating, and in particular to a device for adjusting the electroplating concentration of trivalent iron and a pulse copper plating method thereof. Background Art

[0002] PCB (Printed Circuit Board), whose Chinese name is printed circuit board, abbreviated as printed circuit board, is an important electronic component and a carrier for electrical connection of electronic components. Vertical continuous plating line (Vertical Consecutive Plating, abbreviated as VCP) is widely used in PCB electroplating production.

[0003] The copper plating process is mainly divided into two types: soluble anode and insoluble anode. As the electroplating progresses, the copper ions in the electroplating solution are continuously consumed, and the copper plating effect decreases accordingly, thereby affecting the electroplating effect. Therefore, copper ions need to be supplemented in the electroplating solution. There are many ways to supplement copper ions, such as using phosphor copper balls as soluble anodes and dissolving phosphor copper balls to supplement copper ions in the electroplating solution. However, anode mud will be produced during the dissolution of phosphor copper balls, which requires regular line shutdown for cleaning, consuming a lot of manpower and time, and has a low degree of automation.

[0004] The insoluble anode copper plating process uses an insoluble anode to oxidize the divalent iron in the plating solution into trivalent iron. The trivalent iron then dissolves pure copper to replenish the copper ions in the plating solution. This process has the advantages of not producing anode mud and requiring no regular cleaning of the plating tank. However, the trivalent iron content in the trivalent iron copper dissolving system cannot be controlled, and copper plating production lines often shut down due to uncontrolled trivalent iron concentrations. If the trivalent iron concentration in the plating solution is too low, the amount of copper dissolved will decrease, resulting in insufficient copper ion replenishment and an uneven coating after electroplating. If the trivalent iron concentration is too high, this will reduce the copper plating efficiency on the PCB board. Excessive trivalent iron will react with the coating on the PCB board, causing back etching and damaging the coating.

[0005] At present, the anode plating solution in the electroplating production line is generally circulated and transported into the copper dissolving tank by a centrifugal pump, and the concentration of trivalent iron entering the copper dissolving tank cannot be accurately controlled. In addition, the trivalent iron in the anode plating solution is unevenly distributed. The plating solution near the anode part has a higher trivalent iron concentration, and the plating solution far away from the anode part has a low trivalent iron concentration, which can easily cause fluctuations in the copper ion concentration of the plating solution. After electroplating, the plating quality is unstable. There is also a delivery pump designed with a pumping and pushing function structure for circulating delivery. One side of the piston pumps and pushes the plating solution, while the other side is air. There is a risk of air entering one side of the plating solution. When air enters the copper dissolving tank, the oxygen in the air reacts with the ferrous ions in the plating solution to generate trivalent iron, which still causes the trivalent iron concentration to be too high. Summary of the Invention

[0006] The present invention provides a device for adjusting the electroplating concentration of trivalent iron and an insoluble anode pulse copper plating method based on the device, which can accurately adjust the concentration of trivalent iron in the electroplating solution entering the copper dissolving tank, and can adjust the concentration of Fe 3+ The concentration is maintained within the set range, and the delivery flow rate can be accurately controlled to achieve cyclic continuous production of the production line.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A device for adjusting the electroplating concentration of trivalent iron comprises a pump barrel and a driving mechanism, characterized in that: a cavity is provided in the pump barrel, a screw rod parallel to the axis of the pump barrel is provided in the cavity, a piston is slidably connected to the pump barrel, the piston is threadedly connected to the screw rod, the piston is also provided with a valve core mechanism, a Y-shaped rotary joint and a one-way valve joint are provided at one end outside the pump barrel, the one-way valve joint is communicated with the cavity in the pump barrel, the screw rod is a hollow tube structure, one end of which is connected to the rotary joint, and the other end passes through the pump barrel and is connected to the driving mechanism, an extraction hole and a stirring rod are also provided on the screw rod, the extraction hole is communicated with the rotary joint, and the driving mechanism drives the screw rod to rotate and drive the piston to reciprocate in the cavity of the pump barrel;

[0009] Its mixing device also includes a controller. The rotary joint is also provided with a feed interface and a replenishing interface. The feed interface is provided with a trivalent iron concentration sensor, and the replenishing interface is provided with a solenoid valve. The controller is electrically connected to the motor, the trivalent iron concentration sensor, and the solenoid valve respectively.

[0010] The stirring rods are arranged obliquely and are fixed on the screw rod in a circular array.

[0011] A trivalent iron concentration sensor is also provided on one side of the piston facing the stirring rod and is connected to the controller.

[0012] The driving mechanism includes a motor, a driving wheel, and a driven wheel. The driving wheel is installed on the output shaft of the motor, and the driven wheel is installed on one end of the screw rod with an extraction hole. A belt drive connection is provided between the driving wheel and the driven wheel. A guide rod parallel to the screw rod is also provided in the pump barrel, and the piston is sealed and slidably connected to the guide rod.

[0013] Furthermore, the motor is a servo or stepper motor, and a bracket 1 and a bracket 2 are provided outside the pump barrel, and the bracket 2 is used to fix the motor.

[0014] The piston is provided with a valve core mechanism including a through hole, a sealing plate, a baffle, and a spring. The sealing plate is provided with a short shaft connecting the baffle. The sealing plate is located on one side of the piston and covers one end of the through hole. The spring is sleeved on the short shaft. One end of the spring is connected to the baffle, and the other end is connected to the piston.

[0015] A pulse copper plating method is implemented by a trivalent iron concentration adjustment device, and the copper plating method includes the following steps:

[0016] 1) providing an electroplating tank comprising an electroplating solution, a cathode region, and an anode region, wherein the cathode region is provided with a cathode component, which is a PCB board, and the anode region is provided with an anode component and an anode plating solution; providing a copper dissolving tank, which has five independent chambers arranged from left to right, the five chambers being connected by overflow valves, and each of the five chambers containing a pure copper ball; using a mixing device to connect the anode region of the electroplating tank to the front copper dissolving tank, and using a circulating pump to connect the rear copper dissolving tank to the electroplating tank, thereby forming a circulating electroplating system;

[0017] 2) The anode components in the anode area react with the anode plating solution. A mixing device is then used to extract the anode plating solution from the anode area of ​​the electroplating tank, adjust the Fe3+ concentration in the anode plating solution, and then transport it into the copper dissolving tank. The mixed plating solution enters the copper dissolving tank and flows through the five tank chambers in sequence, reacting with the pure copper balls therein to generate the cathode plating solution.

[0018] 3) Using a circulating pump, the cathode plating solution generated in the copper dissolving tank is transported to the cathode area of ​​the electroplating tank, and the cathode is energized for electroplating;

[0019] The above 2) to 3) are connected in sequence for cyclic electroplating.

[0020] The cathode plating solution mass concentration components generated in 2) are:

[0021]

[0022] The anode member adopts an insoluble anode lrO2 / Ti, and during the cathode electroplating, the current density is 10-40ASF, the forward current time is 10-200ms, and the reverse current time is 0.5-10ms.

[0023] The preparation method of the preparation device (1) in 2) is:

[0024] S1: The feed interface is connected to the anode area of ​​the electroplating tank through a pipeline, and the replenishing interface is connected to the replenishing tank through a pipeline. The replenishing tank stores replenishing liquid. There are two types of replenishing liquids, namely ferric sulfate solution and DI water. The one-way valve joint is connected to the copper dissolving tank through a pipeline;

[0025] S2: The motor drives the piston to move to the left through the screw, extracting the plating liquid in the plating tank from the feed interface into the screw, and then into the pump barrel from the extraction hole of the screw. At the same time, the trivalent iron concentration sensor at the feed interface detects the Fe in the plating liquid entering the pump barrel. 3+ concentration, and transmit the detection signal to the controller. If Fe 3+If the concentration of Fe3+ is lower than 3-9g / L, the controller opens the solenoid valve at the replenishing interface to allow the ferric sulfate replenishing solution to enter the pump barrel for replenishment. If the Fe3+ detected is higher than 3-9g / L, DI water is allowed to enter the pump barrel to dilute the concentration. The screw rotates and drives the stirring rod to stir and mix the plating solution and the replenishing solution evenly. The stirring rod is tilted to increase the contact area with the plating solution, so that the plating solution and the replenishing solution are fully mixed. The trivalent iron concentration sensor on the piston 13 detects the Fe in the mixed plating solution. 3+ Concentration, when Fe 3+ When the concentration reaches the set range, the solenoid valve is closed;

[0026] S3: After the plating solution is prepared, the motor reverses and the piston moves to the right. The prepared plating solution on the right side of the piston pushes away the sealing piece on the piston and enters the left side of the piston from the through hole. After the piston reaches the rightmost side, the motor rotates forward and the piston moves to the left, pushing the prepared plating solution on the left side out from the one-way valve joint. At the same time, the next preparation is carried out on the right side of the piston.

[0027] The anode plating solution preparation method of the described 2) is:

[0028] SS1, add 3 / 4 of the plating tank volume of DI water;

[0029] SS2, add analytical grade sulfuric acid and stir continuously;

[0030] SS3, add copper sulfate and stir to dissolve in the plating solution;

[0031] SS4, the solution is cooled to 24-26 ° C, and the pulse copper plating carrier agent PCP725A, pulse copper plating brightener PCP725B, analytical pure hydrochloric acid and ferric sulfate are added to the electroplating solution;

[0032] SS5, add DI water to the required water level;

[0033] SS6, when the plating solution temperature is in the range of 22-26℃, use the dragging plate to drag the tank with 5ASF DC for 2 hours, then 10ASF DC for 4 hours, 15ASF DC for 1 hour, 20ASF DC for 1 hour, and finally 20ASF with a pulse waveform (F / R=1 / 2 20ms / 1ms) for 24 hours.

[0034] The obtained anodic plating solution mass concentration components are:

[0035]

[0036] The present invention has the beneficial effects:

[0037] 1 The mixing device drives the screw to rotate through a servo or stepper motor, thereby driving the piston to move in the pump barrel. By controlling the motor rotation angle and speed, the piston movement distance can be accurately controlled, so as to realize the precise control of the delivery flow rate by means of a rotating motor. The trivalent iron concentration sensor at the feed interface detects the trivalent iron concentration of the electroplating solution entering the pump, and the solenoid valve controls the trivalent iron supplement liquid to enter the pump barrel. After the electroplating solution entering the pump barrel is stirred and mixed, the evenly stirred electroplating solution is detected again by the trivalent iron concentration sensor on the piston to realize the precise control of the trivalent iron concentration. At the same time, the structure of the mixing device ensures that both sides of the piston are always filled with electroplating liquid, avoiding the Fe2+ that enters the pump barrel and is then transported to the copper dissolving tank to react with ferrous ions. 3+ The phenomenon of high Fe 3+ The precise control of concentration, this mixing device completely realizes the precise control of trivalent iron concentration, feeding, and ensures that the system can continuously cycle copper plating with a rotary drive structure. It can achieve three functions at the same time with a simple structure. It is particularly suitable for insoluble anode copper plating, ensuring that the Fe content of the electroplating solution entering the copper dissolving tank is 3+ The concentration is always 3-9g / L, maintaining the balance of copper ion and ferric ion concentration in the copper dissolving tank to improve production efficiency and capacity and ensure the quality of the coating.

[0038] 2. The circulating copper plating method based on the deployment device avoids the phenomenon of line stoppage caused by the inability to control the concentration of trivalent iron, effectively ensuring the coating quality and production capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the deployment device structure.

[0040] Figure 2 It is a cross-sectional schematic diagram of the deployment device.

[0041] Figure 3 Schematic diagram of the piston structure.

[0042] Figure 4 This is a schematic diagram of the copper dissolving tank, electroplating tank, and trivalent iron concentration adjustment device.

[0043] Figure 5 Fe 3+ Concentration and plating efficiency table.

[0044] Figure 6 This is a table showing the copper sulfate concentration of the cathode plating solution during continuous production.

[0045] Numbers in the figure: 1-ferric iron concentration adjustment device; 2-copper dissolving tank; 3-electroplating tank; 4-rotary joint; 5-one-way valve joint; 6-pump barrel; 7-bracket one; 8-bracket two; 9-circulating pump; 11-motor; 12-screw rod; 13-piston; 14-guide rod; 15-driving wheel; 16-driven wheel; 17-belt; 41-feed interface; 42-supplement interface; 121-extraction hole; 122-stirring rod; 131-rubber nut; 132-through hole; 133-sealing plate; 134-blocking plate; 135-spring. DETAILED DESCRIPTION

[0046] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0047] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0049] refer to Figure 1 、 2The trivalent iron concentration adjusting device 1 includes a pump barrel 6 and a driving mechanism. A cavity is provided in the pump barrel 6, and a piston 13 is provided in the cavity. The piston 13 matches the cavity. A screw rod 12 parallel to the axis of the pump barrel 6 is provided in the cavity. The piston 13 is sealed and threadedly connected to the screw rod 12 through a rubber nut 131, which ensures the sealing effect of the piston 13 and the screw rod 12. A guide rod 14 parallel to the screw rod 12 is also provided in the pump barrel 6. The driving mechanism drives the piston 13 to move back and forth in the cavity of the pump barrel 6 through the screw rod 12. The guide rod 14 plays a guiding role to prevent the piston 13 from rotating and make it move only linearly. A valve core mechanism is provided on the piston 13, and the piston 13 is sealed and slidably connected to the guide rod 14. The screw rod 12 has a hollow tube structure inside. One end of the screw rod 12 is connected to the rotary joint 4. The rotary joint 4 is a Y-shaped structure, on which a feed interface 41 and a replenishing interface 42 are provided. The other end is provided with an extraction hole 121, and the extraction hole 121 is connected to the feed interface 41 and the replenishing interface 42. The rotary joint 4 and the one-way valve joint 5 are both arranged at one end outside the pump barrel 6, and the one-way valve joint 5 passes through the pump barrel 6 and is connected to the cavity inside it. A trivalent iron concentration sensor is provided at the feed interface 41, and an electromagnetic valve is provided on the replenishing interface 42.

[0050] Please refer to Figure 3 A through hole 132 is provided on the piston 13, and the valve core mechanism includes a sealing plate 133, a baffle 134, and a spring 135. A short shaft connecting the baffle 134 is provided on the sealing plate 133. The sealing plate 133 is located on one side of the piston 13 and covers one end of the through hole 132. The spring 135 is sleeved on the short shaft. One end of the spring 135 is connected to the baffle 134, and the other end is connected to the piston 13.

[0051] Furthermore, a bracket 17 is provided at one end of the pump barrel 6 to fix the motor 11, and a bracket 2 8 is provided at the other end. The motor 11 is located outside the pump barrel 6. The driving mechanism includes a motor 11, a driving wheel 15, and a driven wheel 16. The driving wheel 15 is installed on the output shaft of the motor 11, and the driven wheel 16 is installed on one end of the screw rod 12 with an extraction hole 121. A belt 17 is provided between the driving wheel 15 and the driven wheel 16 for transmission connection. The motor 11 adopts a stepping or servo motor to ensure the control accuracy and movement accuracy of the piston 13. By controlling the speed and rotation angle of the motor 11, the delivery amount and flow rate of the electroplating solution pushed into the copper dissolving tank 2 can be accurately controlled to achieve the control of the amount of dissolved copper, which is convenient for calculating the amount of copper ions to be supplemented and maintaining the Fe in the electroplating solution. 3+ and Cu 2+ Ion concentration balance, avoiding Fe 3+ Prevent line stoppage caused by imbalance, improve production efficiency and ensure electroplating quality.

[0052] Specifically, the pump barrel 6, screw rod, piston 13, rotary joint 4, and one-way valve joint 5 of the trivalent iron concentration adjustment device 1 are all made of iron-free parts or other non-Fe 3+ Reactive materials are made to avoid Fe 3+ Reacts with Fe to form Fe 2+ Reduce Fe in plating solution 3+ concentration, ensuring Fe 3+ Always stay within the allocated range.

[0053] refer to Figure 4 , a pulse copper plating method

[0054] An electroplating tank 3 is provided, which includes an electroplating solution, an anode area, and a cathode area. The anode area and the cathode area are separated by a diaphragm. An anode component and an anode electroplating solution are provided in the anode area. The anode component adopts an insoluble anode lrO2 / Ti. The Fe in the anode electroplating solution 2+ The insoluble anode lrO2 / Ti undergoes oxidation reaction to generate Fe 3+ , the reaction formula is Fe 2+ -e→Fe 3+ A cathode component is provided in the cathode area, and the cathode component is a PCB board.

[0055] A copper dissolving tank 2 is provided, which has five independent chambers from left to right, the five chambers being connected by overflow valves, pure copper balls being placed in each of the five chambers, a mixing device being used to connect the anode area of ​​the electroplating tank to the first chamber of the copper dissolving tank, and a circulation pump 9 being used to connect the fifth chamber of the copper dissolving tank to the electroplating tank;

[0056] The ferric iron concentration mixing device 1 is used to extract the anode plating solution and Fe 3+ The concentration is adjusted to the set range and transported to the first chamber of the copper dissolving tank 2. After the prepared anode plating solution enters the copper dissolving tank 2, Fe 3+ React with the pure copper ball inside to replenish copper ions, and the reaction is Cu 0 +2Fe 3+ →2Fe 2+ +Cu 2+ .

[0057] The circulating pump 9 transports the electroplating solution generated in the copper dissolving tank 2 to the cathode area of ​​the electroplating tank 3. The cathode is energized to perform copper plating, and a coating is formed on the surface of the PCB. The reaction formula is Cu 2+ +2e→Cu 0 After electroplating, the cathode plating solution flows back to the anode area to form a circulating copper plating system. During cathode electroplating, the current density is 10-40ASF, the forward current time is 10-200ms, and the reverse current time is 0.5-10ms.

[0058] The preparation method of the ferric iron concentration preparation device 1 includes the following steps:

[0059] S1: The feed interface 41 is connected to the anode area of ​​the electroplating tank 3 through a pipeline, and the replenishing interface 42 is connected to a replenishing tank (not shown) through a pipeline. The replenishing tank stores replenishing liquid. There are two types of replenishing liquids, namely ferric sulfate solution and DI water. The one-way valve connector 5 is connected to the copper dissolving tank 2 through a pipeline;

[0060] S2: The motor 11 drives the piston 13 to move to the left through the screw 12, extracting the plating liquid in the plating tank 3 from the feed interface 41 into the screw 12, and then into the pump barrel 6 from the extraction hole 121 of the screw 12. At the same time, the trivalent iron concentration sensor at the feed interface 41 detects the Fe in the plating liquid entering the pump barrel 6. 3+ concentration, and transmit the detection signal to the controller. If Fe 3+ If the concentration of Fe3+ is lower than 3-9g / L, the controller opens the solenoid valve at the replenishing interface 42 (not shown in the figure, the solenoid valve adopts a two-position three-way solenoid valve) to allow the ferric sulfate (ferric sulfate provides Fe3+ ions) replenishing liquid to enter the pump barrel 6 for replenishment. If the Fe3+ is detected to be higher than 3-9g / L, DI water is allowed to enter the pump barrel 6 to dilute the concentration. The screw 12 rotates and drives the stirring rod 122 to stir and mix the plating solution and the replenishing liquid. The stirring rod 122 is tilted to increase the contact area with the plating solution so that the plating solution and the replenishing liquid are fully mixed. The trivalent iron concentration sensor on the piston 13 detects the trivalent iron concentration in the mixed plating solution. When the trivalent iron concentration reaches the set range, the solenoid valve is closed.

[0061] S3: The electroplating liquid prepared on the right side of the piston 13 pushes the sealing piece 133 on the piston 13 and enters the left side of the piston 13 from the through hole 132. After the piston 13 reaches the rightmost side, the motor 11 rotates forward and the piston 13 moves to the left, pushing the electroplating liquid prepared on the left side out from the one-way valve joint 5. At the same time, the right side of the piston 13 performs the next preparation. During the pushing process of the piston 13, both sides of the piston 13 are always filled with electroplating liquid, which prevents air from entering the pump barrel and then being transported to the copper dissolving tank to react with ferrous ions to cause Fe 3+ The reaction formula is 4Fe 2+ +O2+2H2O→4Fe 3+ +4OH - , further realizing the precise control of Fe3+ concentration, the one-way valve connector 5 can prevent the electroplating solution in the copper dissolving tank 2 from flowing back into the mixing device 1.

[0062] refer to Figure 5 、 6 , Fe in the plating solution 3+ The concentration is adjusted to 3-9g / L and transported to the copper dissolving tank 2 and flows through 5 tank chambers in sequence. 3+The concentration decreases step by step, and the final cathode plating solution has Cu 2+ The concentration is controlled at 60-90g / L, Fe 3+ The concentration is less than 1.2g / L, making the electroplating efficiency on the cathode more than 95%, realizing the Cu 2+ and Fe 3+ Concentration balance and control ensure that the system can continuously cycle copper plating to meet continuous production. The resulting plating layer on the PCB board is uniform, improving copper plating efficiency and production capacity.

[0063] The mass concentration components of the cathode plating solution are as follows:

[0064] name Setting value Control scope Copper sulfate CuSO4.5H2O 75g / l 60-90g / l Sulfuric acid (density: 1.84) 130ml / l 110-140ml / l Chloride ions 50ppm 40-60ppm Pulse copper plating carrier agent PCP 725A 12ml / l 8-20ml / l Pulse copper plating brightener PCP 725B 0.4ml / l 0.25-0.6ml / l Total iron 4.5g / L 4-6g / L Trivalent Fe3+ / <1.2g / L

[0065] In addition, before copper plating, it is necessary to prepare the anodic plating solution, which is a conventional plating solution.

[0066] The procedure for preparing the anodic plating solution includes the following:

[0067] S1, add 3 / 4 of the volume of the plating tank to DI water;

[0068] S2, add analytical grade sulfuric acid and stir continuously;

[0069] S3, add copper sulfate and stir to dissolve it in the electroplating solution;

[0070] S4, the solution is cooled to 24-26°C, and the pulse copper plating carrier PCP725A, pulse copper plating brightener PCP725B, analytical pure hydrochloric acid and ferric sulfate are added to the electroplating solution;

[0071] S5, add DI water to the set required water level;

[0072] S6, when the plating solution temperature is in the range of 22-26℃, use the dragging cylinder plate to drag the cylinder with 5ASF DC for 2 hours, then 10ASF DC for 4 hours, 15ASF DC for 1 hour, 20ASF DC for 1 hour, and finally use 20ASF, pulse waveform (F / R=1 / 2 20ms / 1ms) to drag the cylinder continuously for 24 hours.

[0073] The mass concentration components of the obtained anodic plating solution are:

[0074]

[0075]

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A device for adjusting the electroplating concentration of trivalent iron, comprising a pump barrel (6) and a drive mechanism, characterized in that: The pump barrel (6) is provided with a cavity, and a screw rod (12) parallel to the axis of the pump barrel (6) is provided in the cavity. A piston (13) is also slidably connected in the pump barrel (6), and the piston (13) is threadedly connected to the screw rod (12). The piston (13) is also provided with a valve core mechanism. A Y-shaped rotary joint (4) and a one-way valve joint (5) are also provided at one end outside the pump barrel (6). The one-way valve joint (5) passes through the pump barrel (6) and is connected to the cavity therein. The screw rod (12) is a hollow tube structure, one end of which is connected to the rotary joint (4), and the other end passes through the pump barrel (6) and is connected to the driving mechanism. An extraction hole (121) and a stirring rod (122) are also provided on the screw rod (12). The extraction hole (121) is connected to the rotary joint (4). The driving mechanism drives the screw rod (12) to rotate and drive the piston (13) to reciprocate in the cavity of the pump barrel (6). The piston (13) is provided with a rubber nut (131), and the screw rod (12) is connected to the piston (13) through the rubber nut (131). The valve core mechanism includes a through hole (132), a sealing plate (133), a baffle (134), and a spring (135). The sealing plate (133) is provided with a short shaft connecting the baffle (134). The sealing plate (133) is located on one side of the piston (13) and covers one end of the through hole (132). The spring (135) is sleeved on the short shaft. One end of the spring (135) is connected to the baffle (134), and the other end is connected to the piston (13); The mixing device (1) further comprises a controller, the rotary joint (4) is further provided with a feed interface (41) and a replenishing interface (42), the feed interface (41) is provided with a trivalent iron concentration sensor, the replenishing interface (42) is provided with a solenoid valve, the driving mechanism comprises a motor (11), and the controller is electrically connected to the motor (11), the trivalent iron concentration sensor, and the solenoid valve respectively; A trivalent iron concentration sensor is also provided on one side of the piston (13) facing the stirring rod (122), and is connected to the controller.

2. The electroplating concentration adjustment device of trivalent iron according to claim 1, wherein: The stirring rods (122) are arranged at an angle and are fixed on the screw rod (12) in a circular array.

3. The electroplating concentration adjustment device of trivalent iron according to claim 1, wherein: The driving mechanism further comprises a driving wheel (15) and a driven wheel (16), wherein the driving wheel (15) is mounted on the output shaft of the motor (11), and the driven wheel (16) is mounted on one end of the screw rod (12) provided with an extraction hole (121), and a belt (17) is provided between the driving wheel (15) and the driven wheel (16) for transmission connection, and a guide rod (14) parallel to the screw rod (12) is further provided in the pump barrel (6), and the piston (13) is sealed and slidably connected to the guide rod (14).

4. A pulse copper plating method, characterized in that: The pulse copper plating method is implemented by using the trivalent iron electroplating concentration adjustment device according to any one of claims 1 to 3, and the copper plating method includes the following: 1) An electroplating tank (3) is provided, comprising an electroplating solution, a cathode region, and an anode region, wherein a cathode component is provided in the cathode region, wherein the cathode component is a PCB board, and an anode component and an anode electroplating solution are provided in the anode region; a copper dissolving tank (2) is provided, wherein five mutually independent tank chambers are sequentially provided from left to right, wherein the five tank chambers are connected by overflow valves, and pure copper balls are placed in all the five tank chambers; a mixing device (1) is used to connect the anode region of the electroplating tank (3) to the front copper dissolving tank (2), and a circulating pump (9) is used to connect the rear copper dissolving tank (2) to the cathode region of the electroplating tank (3), thereby forming a circulating electroplating system; 2) The anode component in the anode area reacts with the anode plating solution, and then the mixing device (1) is used to extract the anode plating solution in the anode area of ​​the electroplating tank (3), and Fe in the anode plating solution is mixed. 3+ The concentration is adjusted and then transported into the copper dissolving tank (2). The adjusted anode plating solution enters the copper dissolving tank (2) and flows through the five tank chambers in sequence and reacts with the pure copper balls therein to generate cathode plating solution. 3) using a circulating pump (9) to transport the cathode plating solution generated in the copper dissolving tank (2) to the cathode area of ​​the electroplating tank (3), and energizing the cathode to perform electroplating; The above 2) to 3) are electroplated in a cycle.

5. A pulse copper plating method according to claim 4, characterized in that: The cathode plating solution mass concentration components generated in 2) are:

6. A pulse copper plating method according to claim 4, characterized in that: The anode member adopts an insoluble anode lrO2 / Ti, and the cathode is electroplated: Current density 10-40ASF, forward current time 10-200ms, reverse current time 0.5-10ms.

7. The pulse copper plating method according to claim 4, wherein: The preparation method of the preparation device (1) in 2) is: S1: The feed interface (41) is connected to the anode area of ​​the electroplating tank (3) through a pipeline, and the replenishing interface (42) is connected to a replenishing tank through a pipeline. The replenishing tank stores replenishing liquid, and there are two types of replenishing liquid, namely ferric sulfate solution and DI water. The one-way valve joint (5) is connected to the copper dissolving tank (2) through a pipeline; S2: The motor (11) drives the piston (13) to move to the left through the screw (12), extracting the anode plating solution in the electroplating tank (3) from the feed interface (41) into the screw (12), and then into the pump barrel (6) from the extraction hole (121) of the screw (12). At the same time, the trivalent iron concentration sensor at the feed interface (41) detects the Fe in the anode plating solution entering the pump barrel (6). 3+ concentration, and transmit the detection signal to the controller. If Fe 3+ If the concentration is lower than 3-9 g / L, the controller opens the solenoid valve at the supplement interface (42) to allow the ferric sulfate supplement solution to enter the pump barrel (6) to supplement Fe 3+ If Fe is detected 3+ If the concentration of Fe is higher than 3-9 g / L, DI water is introduced into the pump barrel (6) for dilution. The screw (12) rotates and drives the stirring rod (122) to stir the anode plating solution and the replenishing solution, so that the anode plating solution and the replenishing solution are fully mixed. The ferric iron concentration sensor on the piston (13) detects the ferric iron concentration in the mixed anode plating solution. When Fe 3+ When the concentration reaches the set range, the solenoid valve is closed; S3: After the anodic plating liquid is prepared, the motor (11) rotates in reverse, the piston (13) moves to the right, and the anodic plating liquid prepared on the right side of the piston (13) pushes away the sealing sheet (133) on the piston (13) and enters the left side of the piston (13) from the through hole (132). After the piston (13) reaches the rightmost side, the motor (11) rotates forward, the piston (13) moves to the left, and pushes the anodic plating liquid prepared on the left side out from the one-way valve connector (5). At the same time, the next preparation is carried out on the right side of the piston (13).

8. The pulse copper plating method according to claim 4, wherein: The initial anode plating solution preparation method of 2) is: SS1, add 3 / 4 of the plating tank volume of DI water; SS2, add analytical grade sulfuric acid and stir continuously; SS3, add copper sulfate and stir to dissolve it in the anode plating solution; SS4, the solution is cooled to 24-26 ° C, and the pulse copper plating carrier PCP725A, pulse copper plating brightener PCP725B, analytical pure hydrochloric acid and ferric sulfate are added to the anode plating solution; SS5, add DI water to the required water level; SS6, when the temperature of the anode plating solution is in the range of 22-26℃, use the dragging plate to drag the cylinder with 5ASF DC for 2 hours, then 10ASF DC for 4 hours, 15ASF DC for 1 hour, 20ASF DC for 1 hour, and finally use 20ASF pulse current to drag the cylinder continuously for 24 hours. The obtained anodic plating solution mass concentration components are:

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