JP2004099938A - Barrel plating device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a barrel plating device and a barrel plating method in which plating of high quality and high efficiency can be performed by improving a current density and a current distribution inside a plating bath. <P>SOLUTION: In the barrel plating device where the inside of a plating bath with an anode 14 dipped is provided with a cylindrical barrel 11 housing a stock to be plated together with cathodes 13, and the barrel 11 is rotated to apply plating to the stock, the cathodes 13 are plurally branched inside the barrel 11. Namely, vertical connection electrodes 17 are erected at the tip parts 13c of the cathodes 13, and further, a plurality of branched electrodes 18 parallel to the rotary axis of the barrel 11 are connected to the connection electrodes 17, so that the cathodes 13 are formed so as to be of plurally branched comb teeth shape. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a barrel plating apparatus and a barrel plating method for electroplating an electronic component, and more particularly, to a technique for improving plating quality and plating efficiency.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, the surface of a material having conductivity has been plated. For example, in an electronic component, a terminal portion for electrical connection has been plated to ensure solderability.
[0003]
As shown in FIG. 6, an apparatus for performing this type of plating includes a barrel 1 that accommodates an electronic component of a material to be plated and rotates around a rotating shaft 1a, and a plating solution that immerses the barrel 1. It comprises a plating bath 2 to be stored, a cathode 3 housed in a barrel 1 together with electronic components, and a plurality of anodes 4 immersed in a plating solution in the plating bath 2 so as to sandwich the barrel 1 therebetween. Barrel plating equipment is known.
[0004]
This barrel plating apparatus rotates a barrel 1 in a plating bath 2 and allows a current to flow between a cathode 3 and an anode 4 to stir an electronic component in the barrel 1 and to connect a terminal portion of the electronic component to the cathode 3. , And the terminal surface is plated.
[0005]
Further, in such a barrel plating apparatus, various devices have been devised in order to perform uniform plating on the terminal portion of the electronic component. For example, in the barrel plating apparatus described in Patent Literature 1, as shown in FIG. 7, a triangular pyramid-shaped rectifier 5 is disposed below an inlet 3 a of a cathode 3 of a barrel 1. In this device, the rectifier 5 moves the electronic component 6 rotated along the inner surface of the barrel 1 in the direction of the rotation axis 1a, thereby agitating the electronic component 6 so that the electronic component 6 is uniformly connected to the cathode 3. The terminals are evenly plated. In this barrel plating apparatus, the tip 3b of the cathode 3 functions as a cathode.
[0006]
In addition, a barrel plating apparatus for performing uniform plating is also described in Patent Literature 2. In this apparatus, the stirring capacity is increased by arranging a stirring plate on an inner surface parallel to the rotation axis of the barrel. Is increasing. Further, in the barrel plating apparatus described in Patent Document 3, two kinds of conductive media having different sizes are charged into the barrel, thereby increasing the chance of conduction with the cathode and the stirring ability to perform uniform plating. ing.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. Hei 9-119000 [Patent Document 2]
Japanese Patent Application Laid-Open No. 8-100294 [Patent Document 3]
JP 2000-260612 A
[Problems to be solved by the invention]
However, in such a conventional barrel plating apparatus, electricity is supplied between the linear cathode 3 housed in the barrel 1 and the anode 4 arranged outside the barrel 1. For this reason, there is a problem in that the flow of current (current density and current distribution) differs depending on the position in the plating bath 2 and the plating quality such as the plating film thickness varies.
[0009]
Further, even if the amount of current is increased to increase the plating efficiency, the plating quality varies because the current density varies depending on the rotational position of the barrel 1. For this reason, there was a problem that the plating time could not be reduced.
[0010]
That is, in order to realize high quality plating in a barrel plating apparatus, it is important to make the current density and current distribution in the plating bath as uniform as possible and to stabilize them.
[0011]
The present invention has been made in view of the above circumstances, and provides a barrel plating apparatus and a barrel plating method capable of improving current density and current distribution in a plating bath and performing high-quality and high-efficiency plating. The purpose is to:
[0012]
[Means for Solving the Problems]
The invention of a barrel plating apparatus that solves the above-mentioned problem is provided in a plating bath in which an anode is immersed, a barrel in which a material to be plated is housed together with a cathode, and the barrel is rotated to plate the material. In the plating apparatus, the cathode is branched into a plurality of pieces in the barrel.
[0013]
According to the present invention, a current can flow between the cathode branched into a plurality of parts in the barrel and the anode outside the barrel. Therefore, the current density between the anode and the cathode can be made uniform over a wide range, and the current distribution between the anode and the cathode can be made uniform over a wide range. In other words, the material accommodated in the barrel has more chances of conduction with the cathode, and its surface is plated with less variation.
[0014]
Here, the cathode is preferably formed in a comb shape and branched into a plurality of tubes, and the length of the branched cathode may be changed so as to move and stir the position of the material in the barrel. .
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to the drawings. FIGS. 1 and 2 are views showing one embodiment of a barrel plating apparatus capable of executing the barrel plating method according to the present invention.
[0016]
1 and 2, a barrel plating apparatus includes a barrel 11 formed in a hexagonal cylindrical shape that rotates around a rotation axis (not shown) while accommodating an electronic component or the like of a material to be plated, and the barrel 11. A plating bath (not shown) for storing a plating solution for immersing the barrel 11, a pair of cathodes 13 introduced and housed in the barrel 11 from both sides of the side wall perpendicular to the rotation axis, and a pair of cathodes 13 in the rotation axis direction of the barrel 11. A plurality of anodes 14 which are immersed and arranged in a plating solution in a plating bath so as to be separated and sandwich the barrel 11 therebetween.
[0017]
The cathode 13 of the barrel plating apparatus is parallel to an introduction portion 13a introduced into the barrel 11 from a position coinciding with the rotation axis of the barrel 11 and a side wall orthogonal to the rotation axis of the barrel 11 from the introduction portion 13a. A bent portion 13b bent so as to be parallel to the rotation axis again after being bent as described above, and a tip portion 13c continuous with the bent portion 13b and parallel to the rotation axis of the barrel 11 are constituted.
[0018]
The cathode 13 is supported so that the leading portion 13c is exposed while the introduction portion 13a and the bent portion 13b are insulated, and functions as a cathode portion. That is, the cathode 13 is supported and fixed so as not to rotate with the barrel 11 so that the tip 13c sinks in the plating solution of the plating bath and faces the inner surface parallel to the rotation axis of the barrel 11 at the lowest position. ing.
[0019]
Further, a rod-shaped connecting electrode 17 erected vertically and a plurality of one ends fixed to the connecting electrode 17 so as to be parallel to the rotation axis of the barrel 11 are provided at the tip 13 c of the cathode 13. And a bar-shaped branch electrode 18. The connection electrode 17 and the branch electrode 18 are made of soft copper so as to function as a comb-shaped cathode part branched into a plurality of pieces, and are connected to the leading end 13 c of the cathode 13 in a conductive manner.
[0020]
For this reason, this barrel plating apparatus provides a barrel 11 for accommodating a material such as an electronic component together with a plurality of branched cathodes 13 in a plating bath in which an anode 14 is immersed, and performs plating on the surface of the material. A barrel plating method can be performed. That is, when the barrel 11 is rotated in the plating bath and a current flows between the cathode 13 and the anode 14, the material contained in the barrel 11 is brought into a conductive state with the cathode 13 while being stirred, and The surface is plated. At this time, since the cathode 13 is branched by the branch electrode 18 via the connection electrode 17 of the tip 13c, the tip 13c, the connection electrode 17 and the branch electrode 18 can have a wider electrode area, and A current can be effectively flowed between the tip 14 and the tip 13 c and the electrodes 17 and 18. That is, a current having a similar current density flows in a wide range, and the current distribution becomes uniform over a wide range, so that a plating film with little variation is formed on the surface of the material contained in the barrel 11.
[0021]
Further, the length of each of the branch electrodes 18 of the cathode 13 is set so as to be shorter toward the upper portion to form a substantially triangular cathode portion, and the end face of the other end opposite to the connection electrode 17 is continuous. It is set so as to be inclined toward the inside of the barrel 11. For this reason, the branch electrodes 18 of the pair of cathodes 13 are positioned and fixed in a state of being extended in a direction approaching each other.
[0022]
For this reason, the material accommodated in the barrel 11 is stirred while being moved so as to pass between the branch electrodes 18 by being swung around the inner surface thereof as the barrel 11 rotates. Further, since the lower portion between the branch electrodes 18 of the pair of cathodes 13 is closer to each other, the material located at the lower portion in the barrel 11 is scraped up so as to move upward and is stirred more uniformly. Therefore, by this stirring, a plating film with less variation is formed on the surface of the material.
[0023]
Here, the branch electrode 18 and the connection electrode 17 of the cathode 13 may have any of a round bar shape and a square bar shape, and may have a flat plate shape extending in the horizontal direction. Needless to say, the material of the branch electrode 18 and the connection electrode 17 is not limited to soft copper, and may be made of, for example, stainless steel to improve the strength as long as it is a conductive material.
[0024]
As described above, in the present embodiment, the cathode 13 housed in the barrel 11 can be branched to improve the current density and the current distribution between the anode 14 and the cathode 13. High quality plating can be applied. Therefore, the amount of current flowing between the cathode 13 and the anode 14 can be increased to improve the plating efficiency.
[0025]
As another aspect of the present embodiment, although not shown, the connection electrode 17 and the branch electrode 18 are provided at the tip portion 13c of the cathode 13 so as to form a substantially triangular cathode portion which is turned upside down. Alternatively, in other words, the branch electrodes 18 may be arranged so as to be shorter toward the lower part. Further, the connection electrode 17 and the branch electrode 18 may be provided at the tip portion 13c of the cathode 13 so as to form a substantially triangular cathode portion in which the left and right are inverted. In other words, the connection electrode 17 is provided inside the barrel 11. The branch electrodes 18 may be positioned and extend in a direction away from each other.
[0026]
In addition, as shown in FIG. 3, a plurality of rod-shaped branch electrodes 28 having different lengths may be directly erected on the tip portion 13c of the cathode 13 so as to be vertical. In the case where the branch electrode 28 is provided, it goes without saying that the left and right sides of the substantially triangular shape may be reversed as in the other embodiments described above.
[0027]
Further, a branch electrode 38 of the same length may be connected to the connecting electrode 17 at the tip 13c of the cathode 13 so as to be parallel to the rotation axis of the barrel 11, as shown in FIG. As shown in FIG. 5, the branch electrodes 48 of the same length may be directly erected vertically.
[0028]
It should be noted that the above-described embodiment describes one mode of the embodiment of the present invention, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.
[0029]
【The invention's effect】
According to the present invention, a current can flow between a cathode branched into a plurality of parts in a barrel and an anode outside the barrel, so that the current density between the anode and the cathode is made uniform over a wide range, The surface of the material housed in the barrel can be plated by making the current distribution between the cathode and the cathode uniform over a wide range.
[0030]
Therefore, the material in the barrel has a large number of opportunities for conduction with the cathode, so that high-quality plating with little variation can be applied to the surface of the material, and the amount of electricity can be increased to improve the plating efficiency.
[Brief description of the drawings]
FIG. 1 is a view showing one embodiment of a barrel plating apparatus for executing a barrel plating method according to the present invention, and is a perspective view showing an appearance of the barrel.
FIG. 2 is a vertical sectional view showing a schematic overall configuration of the barrel plating apparatus.
FIG. 3 is a longitudinal sectional view showing a schematic overall configuration of another embodiment of the barrel plating apparatus.
FIG. 4 is a longitudinal sectional view showing a schematic overall configuration of another embodiment of the barrel plating apparatus.
FIG. 5 is a longitudinal sectional view showing a schematic overall configuration of another embodiment of the barrel plating apparatus.
FIG. 6 is a longitudinal sectional view showing a schematic overall configuration of a conventional barrel plating apparatus.
FIG. 7 is a longitudinal sectional view showing a schematic overall configuration of another conventional technique.
[Explanation of symbols]
11 Barrel 13 Cathode 14 Anode 17 Connection electrode 18, 28, 38, 48 Branch electrode

Claims (3)

In a plating bath in which the anode is immersed, a barrel-shaped barrel that accommodates a material to be plated together with the cathode is provided, and a barrel plating apparatus that rotates the barrel to plate the material is provided.
A barrel plating apparatus, wherein the cathode is branched into a plurality of pieces in the barrel. 2. The barrel plating apparatus according to claim 1, wherein the cathode is formed in a comb shape and branched into a plurality of pieces. In a plating bath in which the anode is immersed, a barrel-shaped barrel for accommodating a material to be plated together with the cathode is provided, and a barrel plating method of rotating the barrel to plate the material.
A barrel plating method, comprising: arranging a plurality of branched cathodes in the barrel and conducting the material to the cathodes to perform plating.

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