JPS619590A - Electroforming apparatus - Google Patents

Abstract

PURPOSE:To form a pattern which is excellent in transferring characteristics and has uniform film thickness by constituting an anode of plural electrodes having difference in level in case of performing the electro-forming by using an insoluble anode while rotating a matrix formed with fine patterns. CONSTITUTION:A matrix 1 of record is fitted to a rotating cathode 2 and immersed into a nickel plating soln. 5 incorporated in an electrodeposition cell 4 and an Ni-plated film is electroformed on the surface of the matrix 1 having fine patterns by providing an insiluble anode to the position opposite thereto and conducting electricity with a power source 6. In this case, the anode 3 is constituted of both the first anode 3a which is positioned in the center part for the matrix 1 and the second plural anodes 3b-3f which have differences in level for the first anode 3 a and are fitted in the elliptical state or mutually eccentric state around the first anode 3a. The pattern having uniform thickness is electroformed on all the surface of the matrix 1 by providing the parts which have at least two or more kinds of different interpole distances on the concentrical circles that are formed in the direction parallel to the matrix 1 and in the equidistance from the position for the center of rotation of the matrix 1 in the first and the second anodes.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an electroforming apparatus, and more particularly to an anode C2 for electroforming.

(Technical background of the invention and its problems) It is well known that a thin disk-shaped metal plate called a stamper is used in the record manufacturing process (2). I'm n.

In other words, a master disk is first created by carving a pattern in the form of grooves on a lacquer plate using a needle.

Next, this master was coated with silver mirror reaction (two to four electrical layers), and then nickel plating was applied to a thickness of 200 to 30 mm, and the peeled nickel film was used as a master. Next, the master surface was peeled off. After that, nickel plating was applied to obtain a peeled nickel film mother.Furthermore, after the mother surface was peeled, nickel plating was applied and the peeled nickel film was formed.
lBf' is used as a stamper.

On the other hand, master discs are known in which fine patterns are engraved by optically etching a photosensitive resin film coated on a glass plate, for example, in order to increase recording density. A stamper can also be obtained from this master in the same manner as described above.

If a soluble nickel anode is used as an anode when making a stamper from a master disk with such a fine pattern, the metal to be dissolved may oxidize near the pole and form a slime of insoluble precipitates. Alternatively, oxide smut may be generated on the anode surface. There was a problem that these were incorporated into the electroformed nickel film and damaged the fine pattern. In addition, there were other problems such as the fact that the nickel anode (a) was dissolved (C2), which caused the distance between the anode and the cathode to change, making the thickness of the nickel film formed uneven.

These problems can be better solved by using an insoluble anode as the anode, as disclosed in JP-A-58-157984.

However, since the insoluble anodes conventionally used were in the form of a flat plate, the film thickness at the center or periphery of the stamper obtained could be thicker or thinner than other parts even if the master plate to be plated was rotated. The film thickness of the disks reproduced using this product was uneven (there was a point between two points).

[Purpose of the invention]

It is an object of the present invention to provide an electroforming apparatus which has good transferability of fine patterns and can obtain a stamper having a uniform film thickness.

[Summary of the invention]

The present invention provides an electroforming apparatus that performs electroforming using an insoluble anode while rotating a master disk on which a fine pattern is formed.
It consists of a combination of the first anode part and one or more second anode parts provided with a step around the anode part of the WIl, and the first anode part or the second anode part characterized in that there are parts having at least two or more different interpolar distances on concentric circles that are equidistant in a direction parallel to the master disc from the position with respect to the center of rotation of the master disc in the part. It is said that

FIG. 1 is a schematic vertical cross-sectional view showing an example of an electroforming apparatus according to the present invention. In the figure, a master disk 1 is attached to a rotating cathode 2 with its patterned surface exposed. The anode part is made of an insoluble melt electrode and consists of a first anode part located in the center (two corners) and a second anode part arranged around it with a step.
It consists of a combination of 3b, 3c, 3d, 3e, and 3ri. And 11! Plating is carried out by a power source 6 in a plating bath 5 provided in an analysis tank 4;'. The rotating cathode 2 is rotated at a predetermined speed by a motor 7 (2). On the other hand, the plating bath 5 is cleaned by a circulation pump 8 from a dissolution tank 9 through a filtration filter 10 and then supplied to an electrodeposition tank 4 (2). 19th+2 back.

Examples of insoluble anodes used here include a nickel plate coated with gold or platinum, or a titanium plate coated with gold or platinum.
gM1□□□ is provided with a step as shown in 17, which creates different distances between the poles in the radial direction.For example, when using a conventional anode made of a single flat plate: In a position such as the peripheral area where the plating film becomes thick, the distance between the electrodes can be increased, so that the thickness of the plating film can be reduced to a predetermined thickness. At least two or more different interpolar distances are provided on concentric circles that are equidistant from the center of rotation of the original plate in the ra& portion or the second anode portion in a direction parallel to the original plate. This is a schematic diagram illustrating the positive part of the electroforming apparatus according to the present invention!2, for example, as shown in Figure 2. By making the first anode part (3Jl) and the second anode part elliptical, plating is applied only to the first anode part (3A and 1) in a certain part of the rotating master, but the outside As the part rotates, the N&1 anode part (3
Plating is applied alternately from the second anode part (3b) having a different inter-electrode distance from the first anode part (3a), and plating is applied only from the second anode part (3b) on the outside thereof. administered. In this way, for example, the formation of a step in the plating film that is likely to occur in a portion corresponding to the step that occurs when using an anode consisting of a combination of the 11i #1 pole part and the second anode part having a concentric step is prevented. , it is possible to create a plated film with a more uniform thickness. In addition, as another anode that produces the same effect as the electroforming device of the present invention, the third anode
As shown in the schematic diagram, C: a combination of eccentric circles, etc.

For example, in addition to making these plates by punching out a plate-shaped raw material, they can also be made by processing a single piece of raw material while being connected using a press, or by stacking multiple plates. is also possible.

Examples are shown below.

[Embodiments of the invention]

Example 1 Plating was carried out under the following conditions using an electroforming apparatus having the structure shown in FIG.

Glass plate C: Master plate I: Gold 3001-, with fine patterns engraved by optically etching the coated photosensitive resin film.
10001 to impart conductivity to the patterned surface of the master. Next, this master disk 1 was attached to the rotating cathode 2 so that the patterned surface was the exposed surface. As the anode 3, a titanium plate coated with platinum was used. Its shape consists of six elliptical rings as shown in FIG. The master l, which is being rotated by a motor 7 at approximately IQQRPM, is placed in a nickel sulfamate plating bath 5 in an electrodeposition bath 4 by a power source 6 at a rate of 0.25. After nickel plating to the thickness of the bean paste, the electroformed film was peeled off from the master disk, and an electroformed nickel film with gold on the surface was obtained as a master stamper for forming an optical disk. Here, the plating bath 5 contains nickel sulfamate 600.9/j, boric acid 409/1, and pit preventive agent Nystar 806 (product name of Uezai Kogyo Co., Ltd.) la
It was composed of llll.

In addition, plating is performed at a bath temperature of 45°C and a current density of 12A/do? The test was carried out under the condition that the pH of the bath was 4.2±0.2. In this electroforming apparatus, since an insoluble anode is used as an anode, the nickel concentration decreases during plating, and the pH of the bath decreases. Therefore, dissolved seed nickel carbonate (NIC0,.2Ni(O
H), 4H,0), and the nickel concentration and bath p
The Hf&:M latency value was maintained.

The first MA electrode part (3) and the second anode part (3b), (3C), (3
d).

The distances between each of (3e) and (3f) and the cathode are 20, 21, 22, 23, 24, and 5011, respectively.
1, the change in the radial direction of the film thickness is given by the radius 145 al as shown in the curve (al) in Figure 4.
The thickness up to l was 250±2 μm, which was very uniform.

As a comparative example, a conventional flat plate anode was used, and the distance between the electrodes was set to 40.
1111, the change in the stamper film thickness in the radial direction is non-uniform (250 μm) up to a radius of 145 μm, as shown by curve (b) in FIG.

Example 2 Plating was carried out under the same conditions as in Example 1 using positive a made of an eccentric circle as shown in FIG. This anode includes a first anode part (3a) and a second anode part (3b), C3
C), (3d), and (36), and the outer periphery of each anode part is circular, but the white anode part provided inside is provided at an eccentric position.

Also, the S first anode part (3) and the second anode part (3b).

For each of (3C), (3d), and (3e), the distance between the electrodes and the cathode is 2211M, 20fi, and 221111, respectively.
, 2411m, and 50811. As a result, as shown in the curve (al) of FIG. 5, the change in the stamper film thickness in the radial direction was very uniform (250±2 μm) up to the radius 1451111 (2).

In addition, as a comparative example, when a conventional flat plate anode is used and the distance between the rows is 40111, the change in the stamper film thickness in the radial direction is 145 m11+ as shown by the curve (b) in Figure 5.
Up to 250±20/xn, it was non-uniform (=).

〔Effect of the invention〕

As mentioned above, in the electroforming apparatus according to the present invention, the distance between the electrodes is stepped compared to the case where conventional flat plate anodes are used. Depending on the part to be plated, the step in the radial direction that tends to occur when plating may be plated from the first anode part and the second anode part, or from a plurality of anode parts of the second anode part, which have one step difference depending on the part to be plated. This allows the thickness of the stamper to be made uniform.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal section 11i111 of the electroforming apparatus according to the present invention.
FIG. 3 is a schematic diagram showing the shape of an example of an anode used in the electroforming apparatus according to the present invention, viewed from above. FIGS. 4 and 5 are characteristic factors showing changes in the film thickness of the stub bar in the example and the comparative example in the radial direction. 1... Original l 2... Rotating cathode 3...
・Anode 3a...first anode part (3b)
, (3C) , (3d) , (3e), (3f) ---
Second anode part 4...Electrodeposition tank 5...Plating bath 6...Power supply 7...Motor 8.
...Circulation pump 9...Dissolution tank lO...Filtration filter representative Patent attorney Noriyuki Chika (and one other person) Figure 1 Figure 2

Claims (3)

[Claims] (1) In an electroforming device that electroforms using an insoluble anode while rotating a master disk on which a fine pattern is formed, the anode includes a first anode portion located in the center, and a first anode the first anode part and one or more second anode parts provided with a step around the first anode part, and the master disc in the first anode part or the second anode part. From the position relative to the center of rotation of
An electroforming apparatus characterized in that there are parts having at least two or more different distances between poles on concentric circles that are equidistant in a direction parallel to the master disc. (2) The electroforming apparatus according to claim 1, wherein at least one of the first anode portion and the second anode portion has an elliptical shape. (3) The electroforming apparatus according to claim 1, wherein at least one of the first anode portion and the second anode portion has a circular shape and is an eccentric combination.