JPH03226596A - Electroplating device - Google Patents

Abstract

PURPOSE:To uniformly agitate plating liquid and to hold the plating state uniform and to form plating free from an unevenness by integrally forming both the blowout port of pressurized gas in an air supply path and the return port of plating liquid in a circulator thereof. CONSTITUTION:Firstly plating liquid returned through a circulation path 9 of plating liquid is introduced via an orifice 10' worked and formed to the side wall part of a nozzle main body 10. Then this plating liquid is progressed while holding the form of cohesiveness and allowed to nearly vertically collide against the face of the opposed side wall and made particulate. Simultaneously the pressurized gas i.e., compressed air is passed through an orifice 10' worked and formed to the lower part of the nozzle main body 10 and introduced from the rear part of the plating liquid. This plating liquid 1 is made particulate by this high-speed air flow. The particulate liquid is spouted and dispersed into the plating liquid 1 as the micro bubbles at high density. Therefore, the plating liquid is uniformly agitated as a whole or in a wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to an electroplating apparatus, and more particularly to an improvement in an electroplating apparatus equipped with plating solution stirring and circulation functions.

(Prior art) For example, as a means of manufacturing printed wiring boards,
Electrolytic copper plating is performed to build up a copper layer on a thin copper layer formed by chemical copper plating or the like. However, in the above electroplating process, ji3 is generally used.
An electroplating apparatus having a configuration as perspectively shown in the figure is used.

That is, a plating tank 2 containing a plating solution 1, a cathode electrode that supports a plating object 3, for example, a printed wiring board, and is electrically connected to the printed wiring board 3, which is immersed in the plating solution 1 for plating. 4, an anode electrode 5 disposed opposite to the cathode electrode 4, and an air supply blower 6 disposed in the plating tank 2 that blows out pressurized gas to stir the plating solution 1. An electroplating apparatus is used which includes an air supply path 7 and a plating solution circulation path 9 in which the plating solution 1 in the plating tank 2 is circulated by, for example, a circulation pump 8. FIG. 4 is a perspective view of the gas outlet 7a of the air supply path 7, which is disposed in the plating tank 2 and blows out pressurized gas to stir the plating solution 1. Gas blowing lowers b' are formed in a row on the side wall of the vibrator 7b.

(Problems to be Solved by the Invention) However, the following disadvantages are recognized in the electroplating apparatus equipped with the above-mentioned plating solution stirring and circulation functions. That is, pressurized air, for example, blown out from the pressurized gas blowing lowers b' provided in a row on the side wall of the vinyl chloride vibrator 7b, which forms part of the plating solution stirring means, is blown into the vicinity of the object to be plated 3. In this case, there is a problem in that the required stirring or uniform plating cannot be performed efficiently because it is not dispersed almost uniformly in the plating solution 1. In other words, the vibrator 7b
Pressurized gas blowing lowers b provided in a row on the side wall of
Since microscopic bubbles are not released (blown out) from ',
As schematically shown in FIG. 5, the zone in which the plating solution 1 is stirred is uneven, and the required stirring function is not fully achieved. For this reason, practically satisfactory plating efficiency and uniform plating cannot be obtained.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electroplating apparatus that can significantly improve the stirring efficiency of a plating solution.

[Structure of the Invention] (Means for Solving the Problems) The present invention supports a plating tank containing a plating solution, and an object to be plated to be immersed in the plating solution for plating, and
a cathode electrode electrically connected to the cathode electrode, an anode electrode disposed opposite to the cathode electrode, and an air supply path disposed in the plating tank and blowing out pressurized gas to stir the plating solution;
a plating solution circulation path that circulates the plating solution in the plating tank, through a nozzle formed by integrating a pressurized gas outlet of the air supply path and a plating solution return port of the plating solution circulation path,
It is characterized in that a mixed state of both is ejected into the plating solution from the bottom of the plating tank.

(Function) The pressurized gas outlet of the air supply path and the plating solution return port of the plating solution circulation path are integrated into the nozzle, and a mixed state of both is ejected into the plating solution. Because relatively high-density microscopic bubbles are injected,
A wide bubble zone is easily formed in the plating solution, and the plating solution is stirred to be uniform throughout. In other words, uniform plating conditions can be easily established and a desired plating process can be achieved.

(Example) The present invention will be explained in detail below.

The electroplating apparatus according to the present invention includes a plating tank 2 containing a plating solution 1, an object 3 to be plated to be immersed in the plating solution 1 for plating, for example, a printed wiring board, and supports the printed wiring board 3. A cathode electrode 4 electrically connected to the cathode electrode 4, an anode electrode 5 disposed opposite to the cathode electrode 4, and an air supply blower 6 disposed in the plating tank 2 that blows out gas to stir the plating solution 1 are used to perform necessary operations. The plating solution circulation path 9 includes an air supply path 7 through which a gas such as air is introduced, and a plating solution circulation path 9 through which the plating solution 1 in the plating tank 2 is circulated by, for example, a circulation pump 8. The configuration is the same as that shown in FIG. 3 above.

Therefore, the electroplating apparatus according to the present invention is characterized by the following points. That is, as shown in perspective in FIG. 1(a) and in cross section in FIG. 1(b), the gas outlet of the air supply path 7 and the plating solution return of the plating solution circulation path 9 It is particularly configured such that the opening is integrated and a nozzle formed by this integration allows a gas such as air and the plating solution to be mixed and ejected into the plating solution 1 from the bottom of the plating tank. In other words, the plating solution circulation path 9
The returning dripping liquid is injected through an orifice 10' machined into the side wall of the nozzle body 10, while a gas, such as air, is injected through an orifice 10' machined into the lower part of the nozzle body 10. The plating solution is injected from the rear of the plating solution.

Next, the operation or function of the nozzle configured as described above, that is, the ejection mechanism in which the gas blowout port and the plating solution return port are integrated, will be explained. First, the plating solution that has returned through the plating solution circulation path 9 is injected through an orifice 10' formed on the side wall of the nozzle body IO, and is kept in a cohesive form (not dispersed but takes on a columnar shape). (as it remains), collides almost perpendicularly with the opposing side wall surface and becomes atomized. At the same time, a pressurized gas such as compressed air is injected from the rear of the plating solution through an orifice 10' formed in the lower part of the nozzle body 10, and the plating solution is atomized by this high-speed air flow. They are ejected and dispersed into the plating solution 1 as high-density microscopic bubbles.

FIG. 2 schematically shows an example of the stirring state of the plating solution 1 in the electroplating apparatus according to the present invention having the above configuration, and a uniform air zone was formed over a wide range within the plating Wi2. In addition, when electrolytic copper plating was applied to a printed wiring board with a thin chemical copper plating layer in this state, the difference between the maximum and minimum thickness of the formed electrolytic copper plating layer was 5 μm, which is standard. The deviation was also within 5 μm. For comparison, when a printed wiring board was subjected to electrolytic copper plating under the same conditions as above using the electroplating apparatus having the configuration shown in FIG. 3, the maximum thickness of the formed electrolytic copper plating layer was The difference between the value and the minimum value was 10 μm or more, and the standard deviation was also 5 μm or more.

Note that the configuration of the nozzle that mixes and ejects the plating solution that is circulated and injected into the plating solution 1 in the plating tank 2 and the pressurized gas that is also injected into the plating solution 1 is limited to the above method. First, for example, it may be injected diagonally from behind the nozzle so that the two intersect.

[Effects of the Invention] As can be seen from the above description, according to the electroplating apparatus according to the present invention, the plating solution in the plating tank is completely or widely spread by high-density microscopic bubbles. Stirred. That is, in the required electroplating process, since the plating solution is stirred in a -like manner, the plating conditions are also kept constant, and a -like (even) plating can always be achieved.

[Brief explanation of drawings]

FIG. 1(a) is a perspective view showing the configuration of a nozzle for mixing and blowing out circulating plating solution and stirring gas, which is included in an electroplating apparatus according to the present invention, and FIG. A-
2 is a schematic diagram showing the stirring state of the plating solution in the electroplating apparatus according to the present invention, FIG. 3 is a perspective view showing the configuration of a conventional electroplating apparatus, and FIG. 4 is a sectional view taken along line A. FIG. 5 is a perspective view showing the configuration of a stirring gas blow-off nozzle section included in a conventional electroplating apparatus. FIG. 5 is a schematic diagram showing the state of stirring of a plating solution in the conventional electroplating apparatus. 1...Plating solution 2...Plating tank 3...Object to be plated (printed wiring board, etc.) 4
... Cathode electrode 5 ... Anode electrode 6 ... Air supply blower 7 ... Air supply path 7a ... Pressurized gas blow-off port 7b. ...Vibe 7b'...Pressurized gas outlet 8...Circulation pump 9...Plating solution circulation path 10...Nozzle body

Claims (1)

[Claims] a plating tank containing a plating solution; an anode electrode that supports and electrically connects an object to be plated to be immersed in the plating solution; a cathode electrode disposed opposite to the anode electrode; The plating solution includes an air supply path disposed in the tank and blows out pressurized gas to stir the plating solution, and a plating solution circulation path that circulates the plating solution in the plating tank, and a gas outlet of the air supply path and a plating solution circulation path. An electroplating apparatus characterized in that a mixed state of both is ejected into the plating solution from the bottom of the plating tank through a nozzle formed by integrating the plating solution return port of the solution circulation path.