JPS5937360B2 - Metal surface treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal surface treatment apparatus, and more particularly to an apparatus for electrochemically treating a metal surface.

Metal surface treatment technology that utilizes electrochemical reactions has been applied to various fields such as electroplating, electroforming, and anodic oxidation. These are performed by immersing an anode and a cathode in an electrolytic solution and passing an electric current between the two electrodes. In order to efficiently perform this metal surface treatment, various efforts have been made in the past. 31 For example, in electroplating, the electrolytic solution is stirred in order to obtain a good electrodeposit without uneven thickness or abnormal deposition.

By this stirring, the electrolyte can be brought into uniform contact with the cathode, and the electrolyte can be constantly supplied to the cathode.
It can be operated at high current density. Conventionally, stirring of the electrolytic solution has been carried out by air stirring, circulation of the electrolytic solution, rocking of the cathode that is the object to be plated, and the like.

However, in the air stirring method, air bubbles may adhere to the surface to be plated, which may cause unevenness on the plated surface, and in the electrolyte circulation method, unevenness may occur due to the flow of the electrolyte. Currently, the most effective method is the cathode rocking method. This method is known as a cathode rocker, and involves rocking the cathode from side to side in a direction parallel to the plane of a fixed anode. According to this cathode rocker method, the electrolyte comes into contact with the cathode uniformly, resulting in an electrodeposit with an even thickness, and even when applied to an electrolyte containing a surface active agent such as a pit preventive agent, no foaming occurs. It has the advantage that it does not occur. However, in the cathode rocker method, the contact between the cathode and the electrolyte is relatively slow, making it difficult to operate at high electrolyte densities, and the electrolyte is hardly stirred near the anode. This has the disadvantage that the anode is poorly dissolved and the metal ions in the electrolyte are consumed, and the pH of the electrolyte is lowered due to sulfamic acid liberated from, for example, nickel monosulfamate as the electrolyte.

The present invention has been made based on the above background, and it is an object of the present invention to provide a metal surface treatment apparatus that does not suffer from the above-mentioned drawbacks and can be operated at high current density. The metal surface treatment apparatus of the present invention includes an anode and a cathode that face each other and are fixed in parallel at a constant interval, and a mechanism for reciprocating the anode and cathode in a direction perpendicular to the surface of the anode or cathode. It is characterized by this.

An example in which the present invention is applied to electroplating will be described below with reference to the accompanying drawings.

FIG. 1 shows the electrode structure of the device of this invention.

An anode 1 and a cathode 2, each of which is a flat plate, face each other in parallel with a constant interval. The anode 1 and the cathode 2 have a fixing rod 3 made of plastic such as acrylic resin at their lower ends.
, 3. Copper busbars 4, 4 are installed at the upper ends of the anode 1 and cathode 2 for supplying electricity to these electrodes, and these busbars 4, 4 have fixed rods similar to the fixed rods 3, 3 at both ends thereof. It is fixed by 5,5. FIG. 2 shows a configuration in which the electrodes shown in FIG. 1 are installed in a plating tank 6 containing a plating liquid 7 such as nickel sulfamate. During plating, the electrodes 1 and 2 are normally moved back and forth 30 to 300 times per minute by a suitable swinging mechanism 8 in a direction perpendicular to the surface thereof, that is, in the direction shown by the arrow in the figure. This oscillation causes the plating liquid to
, 2 in the vertical direction, a stirring effect can be achieved. That is, since the electrolytic solution is brought into contact with the entire surface of the cathode 2 at the same time under the same pressure, a uniform electrodeposited film without uneven thickness or abnormal deposition can be obtained.

Moreover, the hydrogen gas generated on the surface of the cathode 2 is not adsorbed to the cathode 2 due to this oscillation, thereby preventing the formation of pits.
Furthermore, as a result of increased contact with the electrolytic solution, a new plating solution with a high metal ion concentration can be constantly supplied to the vicinity of the cathode, so plating can be performed at a high current density. Incidentally, in conventional nickel plating using the cathode rocker method, the limiting current density was 20 A/Dm2, but with the device of the present invention, plating can be performed at a current density two to three times or more than that. In addition, in this device of the present invention, since the anode 1 is also oscillated at the same time, the plating solution near the anode 1 is stirred, and as a result, the dissolution of the anode 1 is promoted, and as a result, the metal ions in the plating solution are consumed. As a result, the pH of the plating solution does not decrease due to the released acid, and the generation of black scale is also suppressed.

In addition, as shown in FIG. 1, by providing the anode 1 with a large number of through holes 9 each having a diameter of several milliliters to several centimeters, 7! ) The plating solution between the electrodes 1 and 2 can be easily exchanged, and plating can be constantly performed using new plating solution.

The above-mentioned example is an application of the device of the present invention to electroplating, but the present invention is not limited to this and can be applied to a wide range of general metal surface treatments such as electroplating, anodizing, electrolytic degreasing, electrolytic polishing, and electrolytic corrosion. Can be applied.

It goes without saying that the electrode provided with the through hole is the one that is not treated. Examples of this invention will be described below. Example This example uses a nickel sulfamic acid bath (bath structure: nickel sulfamic acid 6009/T, nickel chloride 10
9/T, boric acid 309/T, sodium lauryl sulfate 0
．． 059/T. This figure shows an example in which the present invention was applied to the production of a glossy nickel foil with a thickness of 60 μm using sodium l,3,6-naphthalene trisulfonate (59/t).

Area 500x5001! A cathode made of a stainless steel plate and an anode made of an Ap-nickel plate of the same size (1
Using an electrode set in which the electrodes (having a large number of through holes of c1rL) were placed facing each other in parallel at intervals of 10(:l!L), a busbar was installed at the upper end, and the lower end was fixed with a fixing rod made of polyvinyl chloride, the electrode set was Electroforming was carried out at a temperature of 60 C, a pH of 4.0 electrode set, and an oscillation rate of 60 times/min.

The limiting current density was 100 A/Dm2, and electroforming could be performed five times faster than the normal cathode rocker method.

The nickel obtained by peeling from the cathode had no pits or abnormal precipitation, and its gloss was even. It was also found that the error in thickness was kept within the range of ±0.5μ, and a uniform electrodeposited film was obtained. Furthermore, the nickel foil was repeated 50 times under the same conditions as above, but no decrease in the pH or nickel ion concentration of the plating bath was observed during this period. Is the stirring done by the master and the anode well? It showed that he understood.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a set of anode and cathode used in the metal surface treatment apparatus of the present invention, and FIG. 2 is a schematic side view of the metal surface treatment apparatus of the present invention. 1... Anode, 2... Cathode, 3, 4...
...Fixing rod, 9...Through hole.

Claims (1)

[Claims] 1. An anode and a cathode that are fixed facing each other in parallel with a certain interval, and a mechanism for reciprocating the anode and cathode in a direction perpendicular to the surface of the anode or cathode. Characteristic metal surface treatment equipment. 2. The metal surface treatment apparatus according to claim 1, wherein the anode or the cathode has a through hole.