JPH06220698A - Device for removing magnetic fine particle contained in plating solution of electroplating device - Google Patents

Abstract

PURPOSE:To attract and remove the fine magnetic material in a plating soln. and to stably form a plating surface excellent in smoothness by fixing a strong magnet to the inner surface of a plating soln transport pipe in the electroplating device. CONSTITUTION:When a large-area material is electroplated with a metal such as Ni, a fine granular Ni is deposited in a plating soln., hence fine protrusions are generated in the plating soln., and the smoothness of the plating surface of the material is deteriorated. To prevent this defect, plural columnar rod- shaped magnets 2 coated with a synthetic resin as the oxidation and corrosion inhibitor are arranged on the inner surface of a circular hollow plating soln. transport pipe 1 in its axial direction. The plating soln. is allowed to flow in the pipe 1 from the upstream side 3 toward the downstream side 4, hence the fine-particle magnetic Ni powder is attracted by the magnet 2 and removed from the soln., and an Ni plating film free of the protrusions of Ni powder and excellent in smoothness is formed on a large-area material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to an optical disc (LD, C
(D, MO, WO) Electroplating equipment for making stampers, the electroplating of a metal body such as nickel (hereinafter simply referred to as plating) on a surface having a large area such as a stamper to a highly accurate smooth surface. The present invention relates to a device for removing fine magnetic particles such as nickel contained in a plating solution for finishing.

[0002]

2. Description of the Related Art In a plating process during a mastering process for forming an optical disk stamper, a signal recorded on a resist is transferred onto a nickel replica (stamper) by plating. This stamper is backside polished,
After processing such as trimming, it becomes a master when making a plastic substrate with a molding machine, but at this time it is desirable that the back surface of the stamper be as smooth as possible. Is transferred to and becomes noise.
For this reason, it is necessary to manufacture a surface as smooth as possible with high precision in the plating step, but the problem here is magnetic fine particles, such as nickel fine particles, in the plating solution generated in the plating step. Therefore, usually, a plating solution is forcedly circulated by a pump, and a filter such as a cloth for cleaning dust and debris contained in the plating solution by a filter, for example, a fine particle removing device provided with a pleated or wound filter is used. ing.

[0003]

A particular problem with a filter of this form installed in a circulation line for removing fine particles of dust and debris generated is to remove magnetic fine particles of 0.5 μm or less. You cannot do it. As a result, defects are likely to occur in the metal layer, for example, the nickel layer plated by the plating apparatus as described above. This is because the magnetic fine particles generated in the plating bath described above are entrapped and adhere to the surface to be plated, resulting in defects such as undesirable convex fine projections, which makes it impossible to form a highly accurate smooth surface. . Therefore, in the present invention, in the plating step during the mastering step, it is possible to remove the magnetic fine particles so that a metal body such as nickel can be plated on a surface having a large area such as a stamper on a highly accurate smooth surface. This is an issue.

[0004]

Therefore, according to the present invention, at least one magnet is provided inside and / or outside the plating solution transport pipe of the circulation system of the plating solution, and the magnet is included in the plating solution. The magnetic fine particles present are removed to solve the above problems.

[0005]

Therefore, the magnetic fine particles contained in the plating solution can be attracted to the magnet by the magnetic force generated by the magnet to easily remove the magnetic fine particles.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the first embodiment of the magnetic particle removing apparatus of the present invention.
FIG. 2 is a schematic perspective view showing an embodiment of FIG. 2, and FIG. 2 is a schematic perspective view showing a second embodiment thereof.

First, the first embodiment of FIG. 1 will be described. Reference numeral 1 denotes an elongated hollow plating solution transport pipe having a circular cross section (hereinafter, simply referred to as "transport pipe"). Reference numeral 2 denotes a cylindrical rod-shaped magnet which is axially positioned on the inner side surface of the transport tube 1 and four magnets are equally divided and bonded and fixed on the inner circumference of the transport tube 1. Samarium cobalt or the like was used as a material for these magnets 2. Further, in this embodiment, in order to prevent oxidative corrosion due to the plating solution used, these magnets 2 are coated with a synthetic resin such as polyethylene or Teflon.

Next, the operation of the magnetic fine particle removing apparatus having such a configuration will be described. The plating solution is forcibly taken out by a pump from the outlet of a plating bath (not shown here), and the magnet 2 of the transport pipe connected to the outlet.
The plating solution is caused to flow from the upstream 3 of the above. This plating solution contains magnetic fine particles generated in the plating bath, and in order to prevent the magnetic fine particles from adhering to the stamper surface, the upstream 3
The magnetic fine particles contained in the plating liquid flowing from are adsorbed by the magnet 2 to remove the magnetic fine particles. The plating solution in the downstream 4 passing through the transport pipe 1 is cleaned and supplied to the plating solution supply port of the above-mentioned plating bath arranged in the downstream 4.

Next, a second embodiment of the present invention will be described with reference to FIG. The same components as those of the first embodiment shown in FIG. 1 and parts showing the same operation are designated by the same reference numerals. In the second embodiment, an elongated hollow transport pipe 1 having a rectangular cross section was used. Further, the magnet 2 is arranged on the outer side surface of the transportation pipe 1 and has a U-shaped or horse-shaped cross section.

In the first embodiment, the magnet 2 coated with the synthetic resin is arranged on the inner side surface of the transport pipe 1. However, if the magnet 2 is arranged inside as described above, it may be difficult to smoothly flow the plating solution. Further, when the service life is long, the coating is deteriorated by the plating solution, and the magnet 2 is oxidized and corroded by the plating solution. In this respect, by disposing the magnet on the outer side surface of the transport tube 1 as in the embodiment of FIG. 2, the problems of the first embodiment described above can be solved.

In any of the embodiments, the shapes and materials of the magnet and the transport tube are not limited to these, but it is preferable to select them according to the conditions for removing the magnetic fine particles.

[0012]

As described above, the transport pipe for the circulation system of the plating solution
By providing at least one magnet inside and / or outside,
Magnetic fine particles contained in the plating solution by this magnet
Cleaning the plating solution with high efficiency to adsorb and remove
You can In addition, especially magnetic fine particles having a particle size of 0.5 μm or less
The child can also be easily removed. Furthermore, cleansing
The stable plating liquid can be supplied to the plating bath, and
Surface, for example, stamper surface, with high-precision smooth surface plating
It can be applied without defects.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a first embodiment of a device for removing magnetic fine particles contained in a plating solution of an electroplating device of the present invention.

FIG. 2 is a schematic perspective view showing a second embodiment of a device for removing magnetic fine particles contained in a plating solution of the electroplating device of the present invention.

[Explanation of symbols]

 1 plating liquid circulation system transport pipe 2 magnet 3 upstream 4 downstream

Claims (1)

[Claims] 1. At least one magnet is provided inside and / or outside a plating solution transport pipe for circulating a plating solution, and magnetic fine particles contained in the plating solution are attracted to the magnet by a magnetic force generated by the magnet. The magnetic fine particles contained in the plating liquid of the electroplating apparatus are removed by removing the magnetic fine particles contained in the plating liquid.