Iron-based horizontal pulse electroplating equipment

Abstract

The utility model discloses iron-based horizontal pulse electroplating equipment which comprises an electroplating tank and a copper dissolving tank used for dissolving pure copper particles to form electroplating liquid, and the copper dissolving tank is connected with the electroplating tank through a conveying pipeline; the electroplating bath comprises a bath body and a plurality of groups of anode boxes arranged in the bath body, each group of anode box comprises a lower frame body arranged at the bottom of the bath body, an upper frame body spaced from the lower frame body, a plating solution spraying device arranged on the lower frame body and the upper frame body, and a titanium mesh flatly laid in the lower frame body, and the titanium mesh of each group of anode boxes is respectively connected with a pulse rectifier. According to the iron-based horizontal pulse electroplating equipment provided by the utility model, the maintenance frequency can be obviously reduced, so that the cost of manpower and material resources is saved, the productivity is improved, the purpose of continuous clean production can be achieved by utilizing a Fe < 2 + > / Fe < 3 + > redox electron pair technology and only by regularly supplementing pure copper particles in the copper dissolving tank, the uniformity of electroplating copper thickness can be improved, and the deep electroplating capability of electroplating can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit board production, in particular to an iron-based horizontal pulse electroplating device. Background Art

[0002] The electroplating process is an important step in the production and manufacturing of circuit boards. First, through chemical reaction, the surface of the epoxy resin hole wall after PCB drilling is metallized, and a thin layer of chemical copper or carbon is deposited on the hole wall. Then, through the electroplating copper process, the surface of the circuit board and the metallized hole wall are electrochemically plated with a layer of copper to meet the electrical performance requirements.

[0003] Electroplating equipment generally includes gantry plating, VCP vertical continuous plating, and horizontal plating. Prior art typically utilizes soluble anode plating. Its primary operating principle is as follows: In a plating bath consisting of water, copper sulfate pentahydrate, sulfuric acid, hydrochloric acid, and copper plating additives, an anode (phosphorus copper balls) and a cathode (circuit board) are energized. A rectifier then exchanges copper ions, dissolving the divalent anodes (phosphorus copper balls) into negative divalent copper ions. Therefore, copper balls must be regularly added during the electroplating process to compensate for the daily conversion of phosphorus copper balls into copper ions. Furthermore, the ratio of soluble anode to cathode area is typically between 1:1 and 1:2, resulting in poor coating uniformity. Furthermore, during the electroplating process, the accumulated copper sludge from the anodic film on the phosphorus copper balls can block power lines, resulting in uneven copper thickness and the formation of copper particles on the board surface. Regular cleaning (typically every 3-6 months) of the copper balls or the use of a carbonizing solution is required, which is costly and requires a treatment cycle of typically 3-5 days, wasting production capacity.

[0004] In view of this, it is necessary to provide a new electroplating equipment to solve the above technical problems. Utility Model Content

[0005] The purpose of the utility model is to provide an iron-based horizontal pulse electroplating equipment, which can significantly reduce the maintenance frequency, thereby saving manpower and material costs and improving production capacity. It only needs to regularly add pure copper particles to the copper dissolving tank to achieve the purpose of continuous clean production, improve the uniformity of the electroplated copper thickness and enhance the deep plating ability of the electroplating.

[0006] The technical solution of the utility model is as follows:

[0007] A horizontal pulse electroplating device for iron series includes an electroplating tank and a copper dissolving tank for dissolving pure copper particles to form an electroplating solution, wherein the copper dissolving tank is connected to the electroplating tank via a conveying pipeline; the electroplating tank includes a tank body, and multiple groups of anode boxes arranged in the tank body, each group of the anode boxes includes a lower frame arranged at the bottom of the tank body, an upper frame spaced apart from the lower frame, a plating solution spraying device arranged on the lower frame and the upper frame, and a titanium mesh laid flat in the lower frame, and the titanium mesh of each group of anode boxes is respectively connected to a pulse rectifier.

[0008] Furthermore, the number of anode boxes provided in each electroplating tank is greater than or equal to 3 groups.

[0009] Furthermore, the distance between two adjacent groups of anode boxes is 3-4 mm.

[0010] Furthermore, it also includes a controller, a sensor for monitoring the current in the electroplating tank, and an alarm, the sensor is electrically connected to the controller, and the controller is electrically connected to the alarm.

[0011] Compared with the prior art, the iron-based horizontal pulse electroplating equipment provided by the present invention has the following beneficial effects:

[0012] 1. The iron-based horizontal pulse electroplating equipment provided by the present invention has titanium mesh laid flat in the lower frame of the anode box at the bottom of the electroplating tank. Each set of titanium mesh is connected to a pulse rectifier. During the electroplating process, the titanium mesh realizes the current transmission between the cations at the anode and the anions at the cathode. Pulse electroplating causes the electroplating circuit to be periodically connected and disconnected. When the electroplating circuit is disconnected, the consumed metal ions diffuse and replenish near the cathode, and when the electroplating circuit is connected, the metal ion concentration near the cathode is restored, so a higher current density can be used. The peak current of pulse electroplating can be much higher than the average current, which promotes the formation rate of crystal seeds to be higher than the growth rate of crystals, reduces concentration polarization, increases the cathode current density, and can increase the deposition rate to make the coating crystals more refined and densely arranged, reduce porosity, and increase hardness, thereby improving the coating quality.

[0013] 2. The iron-based horizontal pulse electroplating equipment provided by the present invention adds a copper dissolving tank, so that pure copper particles are dissolved in the copper dissolving tank in advance and are directly transported to the electroplating tank during electroplating. Since the dissolved copper ion plating solution is used, the electrolytic copper dissolving process is omitted, which saves power consumption, and there is no impurities such as copper particles and copper powder on the surface of the coating, which further improves the quality of the coating; the electroplating solution in the electroplating tank is sprayed onto the surface of the substrate through the plating solution spraying device, which can promote the flow of the electroplating solution, is beneficial to maintain the metal ion concentration in the electroplating solution, and improves the electroplating uniformity and deep plating ability.

[0014] 3. The iron-based horizontal pulse electroplating equipment provided by the present invention also includes a sensor and an alarm for monitoring the current in the electroplating tank. When the sensor detects abnormal conductivity in the electroplating tank or the set current does not match the actual current, the alarm will sound an alarm, thereby promptly handling the problem on site and reducing the impact on the quality of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a schematic structural diagram of the iron-based horizontal pulse electroplating equipment of the present invention;

[0017] Figure 2 yes Figure 1 The schematic diagram of the structure of the electroplating tank in the iron-based horizontal pulse electroplating equipment is shown from another angle. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention and to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, the specific implementation methods of the present invention are further described below.

[0019] It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0020] Please refer to Figure 1 and Figure 2 ,in Figure 1 This is a structural diagram of the iron-based horizontal pulse electroplating equipment of the utility model. Figure 2 yes Figure 1 The iron-based horizontal pulse electroplating equipment of the present invention comprises a copper dissolving tank 1 and an electroplating tank 2, and a conveying pipeline 3 for connecting the copper dissolving tank 1 and the electroplating tank 2.

[0021] The copper dissolving tank 1 is used to dissolve pure copper particles to form an electroplating solution in advance before electroplating and to supplement copper ions during the production process. During electroplating, the circuit board is placed horizontally in the electroplating tank, and the electroplating solution in the copper dissolving tank 1 is transported to the electroplating tank 2 through the delivery pipeline 3. The metal ions in the electroplating solution provide cations, and the circuit board serves as the cathode. Under the action of current, the cations are transmitted between the anode and the cathode, so that a copper plating layer is formed on the circuit board.

[0022] The plating solution utilizes a high-acid, low-copper system, with copper sulfate concentrations controlled between 116-176 g / L, ferrous sulfate concentrations below 1.7 g / L, sulfuric acid concentrations between 180-260 g / L, and chloride concentrations between 40-90 mg / L. Pure copper particles dissolve in the copper dissolving tank, forming copper ions. The ferrous sulfate or ferrous ions in the ferrous sulfate (FeSO4·7H2O) act as a reducing agent, reducing the copper ions to metallic copper. This copper is then deposited on the surface of the conductive copper foil during PCB electroplating, forming a metallic copper layer.

[0023] In the present invention, the electroplating tank 2 includes a tank body 21 and multiple sets of anode boxes 22 disposed within the tank body 21. Each set of anode boxes 22 includes a lower frame 221 disposed at the bottom of the tank body, an upper frame 222 spaced apart from the lower frame, a plating solution spraying device 223 disposed between the upper frame 222 and the lower frame 221, and a titanium mesh 224 flatly disposed within the lower frame. During electroplating, the circuit board is positioned between the upper and lower frames. The liquid spraying device 223 includes a nozzle 227 and multiple nozzles 228 disposed on the nozzle 227. The nozzles on the upper and lower frames 222 and 221 spray the surfaces of both sides of the circuit board substrate. Spraying the plating solution from the nozzles promotes the flow of the plating solution, helps maintain the metal ion concentration in the plating solution, and improves the uniformity and deep-throw capability of the plating process. The titanium mesh is provided with holes corresponding to the nozzles to facilitate the spraying of the plating solution. The electroplating liquid in the electroplating tank is transported to the nozzle of the upper frame / lower frame through the circulation pump 226. Specifically, the liquid outlet of the circulation pump is connected to the electroplating liquid circulation pipe 229, and the nozzle of each group of anode boxes is connected to the electroplating liquid circulation pipe 229.

[0024] The titanium mesh of each anode box is connected to a pulse rectifier (not shown). The titanium mesh 224 not only realizes the current transmission between the positive ions at the anode and the negative ions at the cathode, but also has the functions of filtering impurities and anti-oxidation.

[0025] Pulse rectifiers are AC pulse rectifiers. Compared to conventional DC electroplating, they offer advantages such as smooth and dense coatings, good adhesion, high current efficiency, and environmentally friendly performance. The pulse rectifier periodically switches the electroplating circuit on and off. When the electroplating circuit is disconnected, consumed metal cations diffuse and replenish near the cathode. When the electroplating circuit is reconnected, the metal ion concentration near the cathode is restored, resulting in a higher current density. The peak current of pulse electroplating can be significantly higher than the average current, prompting the formation of seed crystals to be faster than the growth rate of crystals, reducing concentration polarization, increasing cathode current density, and increasing deposition rate, resulting in finer and more densely packed coating crystals, reduced porosity, and increased hardness, resulting in a superior coating quality.

[0026] In this embodiment, the number of anode boxes provided in each electroplating tank is greater than or equal to 3 groups, preferably 4 groups, and the distance between two adjacent groups of anode boxes is 3-4 mm.

[0027] In the present invention, the electroplating tank 2 further includes a controller 24, a sensor 25 for monitoring the current in the electroplating tank, and an alarm 26. The sensor 25 is electrically connected to the controller 24, which is in turn electrically connected to the alarm 26. The sensor 25 is used to monitor the current in the electroplating tank and transmit the monitoring data to the controller. When the carbon brushes are worn or uneven, or the conductive wires fall off during electroplating, causing the sensor to detect abnormal conductivity in the electroplating tank or a discrepancy between the set current and the actual current (a difference of 5%), the alarm 26 is controlled to sound an alarm, thereby promptly addressing the problem on site and minimizing the impact on the quality of the coating.

[0028] The utility model of the iron-based horizontal pulse electroplating equipment utilizes Fe 2+ / Fe 3+ Based on the redox electron pair principle, pure copper particles are used to supplement the copper source during the production process, which can solve the anode mud produced by the shedding of the anode film during the traditional soluble anode electroplating process, reduce the maintenance frequency, save maintenance manpower and material costs, increase production capacity and improve the coating quality.

[0029] The above describes the embodiments of the present invention in detail, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations to these embodiments without departing from the principles and spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. An iron-based horizontal pulse electroplating device, characterized in that: It includes an electroplating tank and a copper-dissolving tank for dissolving pure copper particles to form an electroplating solution, and the copper-dissolving tank is connected to the electroplating tank through a conveying pipeline; the electroplating tank includes a tank body, multiple groups of anode boxes arranged in the tank body, each group of the anode boxes includes a lower frame arranged at the bottom of the tank body, an upper frame spaced apart from the lower frame, a plating solution injection device arranged on the lower frame and the upper frame, and a titanium mesh laid flat in the lower frame, and the titanium mesh of each group of anode boxes is connected to a pulse rectifier respectively.

2. The iron-based horizontal pulse electroplating equipment according to claim 1, characterized in that: The number of anode boxes installed in each electroplating tank is greater than or equal to 3 groups.

3. The iron-based horizontal pulse electroplating equipment according to claim 2, characterized in that: The distance between two adjacent groups of anode boxes is 3-4 mm.

4. The iron-based horizontal pulse electroplating equipment according to any one of claims 1 to 3, characterized in that: It also includes a controller, a sensor for monitoring the current in the electroplating tank, and an alarm. The sensor is electrically connected to the controller, and the controller is electrically connected to the alarm.

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