JPH10226888A - Electroless nickel plating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electroless nickel plating device by which a plating soln. and a reducing agent are excellently mixed and consuming only the necessary minimum amt. of liq. without causing an oxygen-rich atmosphere in a system supporting a glass disk in the horizontal direction. SOLUTION: A glass disk 1 on which a rugged pattern is formed in accordance with a recorded signal is electroless-plated by this device to form the metallic master disk for an optical disk. In this case, the glass disk surface is catalytically activated as the pretreatment, and then a plating soln. contg. nickel ion and a reducing agent are sprayed respectively from the gas spray nozzles 6, 7, 70 and 71 and applied on the glass disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nickel electroless plating apparatus used for an apparatus for manufacturing an optical disk such as a CD or a DVD, which is coated on a glass disk to produce a metal master of the optical disk. Exposure of the photoresist to a laser modulated in accordance with the recording signal, followed by development processing to form a glass disk with an uneven pattern, or the uneven pattern directly on the glass disk according to the recording signal The present invention relates to a nickel electroless plating apparatus for performing nickel electroless plating on a glass disk on which is formed.

[0002]

2. Description of the Related Art Optical disks, such as CDs and DVDs, are copied in large quantities from a master, which is a mold, by a molding machine. The mold is called a stamper and is manufactured in a process called mastering. To briefly explain the mastering step, first, a polished glass substrate is washed, and a photosensitive agent called a photoresist is applied thereon. After that, the laser light modulated by the signal to be recorded is squeezed by a lens to a small diameter of submicron, and is exposed on the glass disk. After the exposure, the exposed portion is etched by applying a developing solution on a glass disk to form a fine uneven pattern on the photoresist. A thin conductive film of nickel is formed thereon by a method called electroless plating or sputtering. This nickel conductive film acts as an electrode during subsequent electroplating. A nickel metal layer is formed on a glass disk to a thickness of about 0.3 mm by electroplating. The nickel metal layer peeled from the glass disk is called a metal master,
Usually, this is processed into a stamper. In such a mastering step, in order to apply electroless plating to the glass disk after the development processing, the surface to be plated must be made catalytically active as a pretreatment. Electroless plating occurs when metal ions in a plating solution combine with minus electrons generated by oxidation of a reducing agent to precipitate a metal. That is,
The oxidation reaction of the reducing agent is an essential condition for electroless plating, and it requires a palladium or nickel catalyst. Then, if the surface to be plated is catalytically active, plating proceeds selectively there. One of the effective treatment methods for activating the surface of the glass disk with palladium is as follows. First, after treating the resist surface with tannic acid, the surface is made sensitive with a sensitizer such as tin chloride, and then a palladium chloride solution is dropped or sprayed as an activator. By this pretreatment, palladium is spread on the surface of the glass disk to activate the catalyst.

[0003]

As a method for applying electroless plating to the above-mentioned glass disk, the following method has been used.
This is a method of immersing a glass disc in a plating bath as shown in FIG. In FIG. 4, 32 is a plating bath, 33 is a plating solution, 31 is a glass disk, and 34 is a holding frame for the glass disk 31. The plating bath 32 contains a plating solution and a reducing agent mixed at an appropriate mixing ratio. In this type of apparatus, a plating solution and a reducing agent are mixed, and a periodic plating bath 32 is used.
Complicated processing such as maintenance of the liquid and waste liquid treatment was required. Also, since the plating solution and the reducing agent are mixed,
Oxidation of the reducing agent causes the deposition of nickel to gradually progress in the plating bath 32, and has the disadvantage that the life of the solution is short.

FIG. 5 shows another electroless plating method. In FIG. 5, 1 is a glass disk, 2 is a glass disk holding member,
Numeral 3 is a rotary drive mechanism, 41 and 42 are pipes for plating solution and reducing agent each having a nozzle at the tip, 43 and 44 are solenoid valves for each solution, 45 and 46 are filters for each solution, 47 and
48 is a pump for each liquid, and 49 and 50 are tanks for each liquid. Here, the glass disk 1 is held horizontally, and a plating solution and a reducing agent are dropped or sprayed on the glass disk 1 from nozzles at the tips of the pipes 41 and 42. The mixed solution held on the glass disk 1 at a surface tension reacts with palladium on the surface of the glass disk 1 as a catalyst, and nickel precipitates. In this method, in order to avoid the drawbacks of the apparatus shown in FIG. 4, each chemical solution, that is, a plating solution and a reducing agent are stored in separate tanks, and are dropped by separate nozzles. Further, reference numeral 49 in FIG. 5 shows a nozzle having another configuration. The nozzle 49 is connected to a plating solution pipe 51 and a reducing agent pipe 52 so that they are mixed immediately before dropping. Mixing just before the dropping just before the nozzle 49 can prevent the liquid from deteriorating. 6 in FIG.
3 is an arm for holding the nozzle 49, 53 and 54 are electromagnetic valves for the plating solution and the reducing agent, 55 and 56 are filters, 57 and 58 are pumps for each solution, and 59 and 60 are tanks for each solution. . However, the disadvantages of these methods are:
It is difficult for the two solutions to mix uniformly, and the plating does not proceed uniformly. In addition, if the positions of the pipes 41 and 42 are devised to mix the two liquids well, oxygen in the air is more likely to be mixed into the liquid in the process. As described above, negative electrons generated by oxidation of a reducing agent under a catalyst are required for nickel metal to be deposited and plating to occur.

[Formula 1] Ni ^{2+ +} 2e → Ni ↓ However, in the oxygen-rich atmosphere, reducing action of oxygen also proceed at the same time, consume a lot of negative electron than the amount required for the reduction of nickel.

O ² + 4e → 2O ^2- Therefore, if there is a large amount of oxygen where the plating reaction is taking place, the precipitation of nickel will not proceed. That is, if the above-mentioned two liquids are mixed well, the mixing of oxygen increases, and there is a disadvantage that plating does not easily occur.

In the above-described horizontal holding system, oxygen diffuses into the liquid from the surrounding atmosphere. It has been practiced to increase the amount of liquid deposited on a glass disk so as not to be affected by the oxygen. In the case of performing electroless plating while holding the glass plate horizontally, the liquid used is disposable. Therefore, if the amount of liquid to be placed on the board is increased, the amount of liquid to be consumed increases accordingly, and there is a disadvantage that the production cost increases. When electroless plating is performed in a plating bath as shown in FIG. 4, depending on the type of plating solution, it is necessary to raise the temperature of the plating solution above room temperature to promote the reaction. However, in the method in which the glass disk is held horizontally, when the processing liquid in the tank is heated, nickel precipitation in the tank progresses and the liquid life is shortened. Must be heated in a reasonable time. Reference numeral 61 shown in FIG. 5 is a heater for the plating solution, and 62 is a heater for the reducing agent. However, there is a disadvantage that the liquid cannot be sufficiently heated to a required temperature during the passage through the pipe. For this reason, methods such as heating the glass plate itself before the electroless plating have been attempted, but the number of steps has been increased and the cost of the apparatus has been increased.

An object of the present invention is to solve the above-mentioned drawbacks by providing a method for supporting a glass disk in a horizontal direction.
It is an object of the present invention to provide a nickel electroless plating apparatus which can mix a plating solution and a reducing agent well, does not have an oxygen-rich atmosphere (an atmosphere containing a large amount of oxygen), and requires only a minimum amount of solution. .

[0007]

In order to achieve the above object, the present invention is configured as follows. First of the present invention
According to the nickel electroless plating apparatus according to the aspect, in order to produce a metal master disk of an optical disk, an apparatus for performing electroless plating on a glass disk having an uneven pattern formed on a glass disk in accordance with a recording signal. Then, after performing a pretreatment step of activating the surface of the glass disk with a catalyst, a plating solution containing nickel metal ions and a reducing agent are atomized by separate gas spray nozzles and applied onto the glass disk. I have to. According to a second aspect of the present invention, in the first aspect, the two gas atomizing nozzles for spraying the plating solution and the reducing agent eject mist-like particles in a straight line, and the straight lines from which the particles are ejected. Can also be arranged so that the directions of them are arranged along the radial direction of the glass plate. According to a third aspect of the present invention, in the first or second aspect, the gas spray nozzle dilutes the plating solution and the reducing agent necessary for the electroless plating reaction with pure water so as to have substantially the same amount. Then, they can be separately sprayed in a mist state. According to a fourth aspect of the present invention, in any one of the first to third aspects,
The gas spray nozzle may also spray the plating solution and the reducing agent in a mist state using nitrogen. According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the gas supplied to the gas spray nozzle for spraying the plating solution and the reducing agent in the form of a spray is about 60 to 80. It may be a gas heated to a high temperature of ° C. According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the glass disc onto which the mist-like plating solution and the reducing agent are respectively sprayed rotates at a low speed of about 10 rpm or less. You can also do it.

[0008]

According to the apparatus of the present invention, the plating solution and the reducing agent are ejected from separate spray nozzles to apply the plating solution and the reducing agent to the glass plate after the pre-treatment. Since it can be supplied separately to the nozzle, the reaction between the reducing agent and the plating solution proceeds during storage,
The life of each chemical is not shortened. Further, since the atomized particles sprayed from each nozzle have a small particle diameter due to the gas spray nozzle, the two liquids are well mixed. Due to this effect, plating can be applied uniformly and quickly over the entire circumference of the glass disk. Further, if the shape of the nozzle is linear, mixing of the two liquids can be performed more quickly and efficiently, and the liquid can be applied to the entire circumference of the glass plate in a short time.
Also, if nitrogen is used as a gas that is supplied to the gas atomizing nozzle and atomizes the liquid, oxygen is expelled from the vicinity where nickel is deposited, there is no reduction reaction of oxygen itself, and negative electrons generated by oxidation of the reducing agent Can be used efficiently for nickel deposition. In addition, since diffusion of oxygen from the ambient atmosphere into the solution can be prevented, a small amount of plating solution and reducing agent can be used, and the production cost is reduced. Further, if heated nitrogen is supplied to the gas spray nozzle, the liquid to be atomized and the glass disk itself can be heated to a high temperature, and the electroless plating treatment at a temperature higher than room temperature can be performed at low cost.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a nickel electroless plating apparatus according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a glass disk after pre-processing, 2 denotes a glass disk holding member that holds the glass disk 1, and 3 denotes a rotation drive mechanism that rotates the glass disk holding member 2, and the glass is driven at a low speed of about 10 rpm. The glass plate 1 is rotated via the plate holding member 2. Reference numeral 4 denotes an arm to which the gas spray nozzles 6 and 7 are attached, and reference numeral 5 denotes a rotation drive mechanism connected to one end of the arm 4 to rotate the arm 4. The nozzle 6 attached to the arm 4 is a nozzle for the plating solution, and is provided from the plating solution tank 14 by the plating solution piping 8 to the filter 1 disposed in the plating solution piping 8.
2. It is connected to the nozzle 6 via an electromagnetic valve 10. The plating solution is sent from the plating solution tank 14 by pressure,
Nitrogen as a gas for applying pressure to the plating solution in the plating solution tank 14 is sent from the compressed nitrogen cylinder 20 to the plating solution tank 14 through the pipe 16 having the flow rate control valve 18. Another pipe 23 comes to the nozzle 6 and supplies compressed nitrogen. Compressed nitrogen cylinder 2
From zero, the compressed nitrogen is sent through a flow control valve 21 to a heater 22 where the compressed nitrogen is heated to a desired high temperature. Usually, it is heated to 60 to 80 ° C. The heated nitrogen is
From the heater 22, the flow control valve 2 disposed in the pipe 23
9, reaches the nozzle 6 via the filter 27 and the electromagnetic valve 25.

The above is a description of the plating solution.
The same applies to the reducing agent. That is, the nozzle 7 attached to the arm 4 is a nozzle for the reducing agent, and the filter 13 and the solenoid valve 11 arranged in the reducing agent pipe 9 are connected to the reducing agent tank 15 by the reducing agent pipe 9. Through the nozzle 7. The reducing agent is sent from the reducing agent tank 15 by pressure feed. Nitrogen as a gas for applying pressure to the reducing agent in the reducing agent tank 15 passes from the compressed nitrogen cylinder 20 through the pipe 17 having the flow rate control valve 19. It is sent to the reducing agent tank 15. Another pipe 24 comes to the nozzle 7 and supplies the compressed nitrogen heated as described above. The nitrogen that has become high temperature in the heater 22 reaches the nozzle 7 via the flow control valve 30, the filter 28, and the electromagnetic valve 26 arranged in the pipe 24.

The application operation of the electroless plating apparatus according to the above configuration will be described below. The above-mentioned electroless plating apparatus exposes a photoresist applied on a glass disk to a laser modulated in accordance with a recording signal, and then performs a developing process to form a concave and convex pattern in order to produce a metal master of an optical disk. The electroless plating is performed on the glass disk on which is formed. First, the pretreatment step of activating the surface of the glass disk 1 with a catalyst is performed, and then the plating solution containing nickel metal ions and the reducing agent are atomized by separate gas spray nozzles 7 and 6 to form the glass disk 1. Apply on top. This application will be described in more detail. Glass disk 1 is 10
When the rotation is started by the rotation drive mechanism 3 at a low speed of about rpm, the arm 4 is rotated by the arm rotation drive mechanism 5, and the arm 4 is rotated with respect to the glass plate 1 (without entering the space above the glass plate 1. , Nozzles 6 and 7, which are located at a position for waiting for coating, are moved to a coating start position on the glass disk 1. Next, the electromagnetic valves 10 and 11 are opened, and the plating solution and the reducing agent are pressure-fed to the respective nozzles 6 and 7.
At the same time, the solenoid valves 25 and 26 are opened, and the compressed nitrogen also reaches the nozzles 6 and 7. Then, each liquid is formed into a fine mist from the gas spray nozzles 6 and 7 and is applied onto the glass plate 1. During this coating operation, the glass disk 1 is rotating at a desired number of revolutions, and the arm rotation drive mechanism 5 slowly rotates the arm 4 so that the plating solution and the reducing agent are carried on the surface of the glass disk 1. And apply evenly. After a lapse of a predetermined time, the solenoid valves 10, 11, 25, and 26 are closed, and the application is completed. The optimal amounts of the plating solution and the reducing agent for performing electroless plating are determined in advance, and the plating solution and the reducing agent are diluted with pure water in advance so that they are equal. If it is stored in each of the tanks 14 and 15, the plating solution and the reducing agent can be sprayed in the optimum amounts in the same spraying time.

As described above, in the first embodiment, the plating solution and the reducing agent, which have become fine particles, are uniformly mixed on the surface of the glass disk 1, and the precipitation of nickel is uniformly performed by the catalytic action of palladium on the surface. Done quickly. In addition, because of the jetted nitrogen atmosphere, a reduction reaction of oxygen hardly occurs, and negative electrons generated from the reducing agent are used only for reduction of nickel. Therefore, only the required amount of the chemical solution to be applied on the glass disk 1 is required, and under certain conditions (for example, depending on the concentration of nickel plating, the concentration of the reducing agent, or the wetting property of the resist surface), 1 mm from the surface of the glass disk 1 It only needs to be applied to the following thickness. In the first embodiment, since the nitrogen supplied to the gas spray nozzles 6, 7 is heated to a high temperature by the heater 22, the electroless plating is performed at a high temperature. However, electroless plating does not necessarily need to be at a high temperature.
Room temperature around 0 ° C. is possible depending on the type and concentration of the chemical solution.

FIGS. 4 and 5 show a nickel electroless plating apparatus according to a second embodiment of the present invention.
4 and 5, reference numeral 1 denotes a glass disk; 70, a gas spray nozzle for a plating solution; 71, a gas spray nozzle for a reducing agent; 72, a pipe for a plating solution; 73, a pipe for nitrogen for a plating solution; A pipe 75 is a pipe for nitrogen for the reducing agent. Nozzle 7
Reference numerals 0 and 71 are fixed to the holding member 76, and the holding members 7
6 is fixed to the tip of the arm 4 described in FIG.
The nozzles 70 and 71 are arranged in parallel and have a long orifice or a row of orifices so as to spray liquid in a straight line. The direction extending linearly coincides with the radial direction of the glass disk 1. Therefore, the liquid can be quickly and quickly applied to the rotating glass disk 1.
The number of rotations of the glass disk 1 is set in accordance with the amount of liquid sprayed per unit time, but preferably at a low speed such that the liquid landing on the glass disk 1 is not pulled to the outer periphery by centrifugal force. Empirically, it is better to be around 10 rpm or below. When the linear mist ejected from the nozzles 70 and 71 is larger than the radius of the glass plate 1, the arm 4 may be fixed. However, when the radius of the glass plate 1 is larger, the mist-like fine particles are removed. The arm 4 rotates by that amount so as to cover the entire circumference of the arm 1. In addition, if the two nozzles 70 and 71 are inclined at a slight angle so that the emission directions of the nozzles face each other, 2
The liquid mixes better on the glass plate 1.

According to the electroless plating apparatus according to each of the above embodiments of the present invention, the gas spray nozzles 6 and 7 are held horizontally, and the pretreatment is completed and the gas spray nozzles 6 and 7 are placed on the glass plate 1 rotating at a relatively low speed. The plating solution and the reducing agent stored in separate tanks 14 and 15 are supplied to respective pipes 8 and 9 respectively.
Through the above-mentioned gas spray nozzles 6 and 7 which are independent from each other, and apply the fine spray. Therefore, in the above-described apparatus, the plating solution and the reducing agent that have become fine particles are
The mixture can be densely mixed on the surface of the glass plate, and the reaction between the reducing agent and the plating solution proceeds during storage, so that the life of each chemical solution is not shortened. Further, the gas spray nozzles 6 and 7 are also called two-fluid spray nozzles. By mixing a liquid and a gas at the nozzle portion, the liquid can be made into a fine mist, and the conventional liquid pressurizing method is not used. The particle size of the generated mist can be made smaller than that of the gas spray nozzle. That is, the atomized particles sprayed from each of the nozzles 6 and 7 have a small particle diameter due to the gas spray nozzle, so that the two liquids are well mixed. Due to this effect, plating can be applied uniformly and quickly over the entire circumference of the glass disk 1.

Further, the nozzles 6 and 7 according to the embodiments of the present invention may be configured such that the fine mist particles are ejected linearly along the radial direction of the glass disk 1. In addition, the two nozzles 6 and 7 can be arranged side by side so as to be well mixed with each other on the glass plate 1. That is, by making the shapes of the nozzles 6 and 7 linear, the mixing of the two liquids can be performed more quickly and efficiently, and the entire circumference of the glass plate 1 can be applied in a short time. As described above, when the atomized particles are sprayed linearly in the radial direction, the glass disk 1 is, for example, 10 r
By rotating the nozzles 6 and 7 in the radial direction while rotating at a low speed of not more than pm, the entire circumference of the glass plate 1 can be uniformly applied. Further, the directions of the emission ports of the nozzles 6 and 7 may be slightly angled so that the mist particles are mixed on the surface of the glass disk.

Further, as an example, the gas supplied to the gas spray nozzles 6 and 7 in the vicinity where the plating solution and the reducing agent deposit nickel with the help of the catalyst on the surface of the glass plate so as to minimize the presence of oxygen is Nitrogen is used. That is, the gas arriving at the glass disk surface together with the atomized liquid is nitrogen that does not contain oxygen, and serves to expel oxygen-containing air from the chamber where the processing is performed. Therefore,
By using nitrogen as the gas supplied to the gas spray nozzles 6 and 7, oxygen can be expelled from the portion of the glass disk surface where nickel is being reduced, and the oxygen reduction reaction can be prevented. Therefore, there is no fear that negative electrons required for nickel reduction are consumed in the oxygen reduction reaction, and the negative electrons generated by oxidation of the reducing agent can be efficiently used for nickel precipitation, and oxygen diffusion from the surrounding atmosphere. Therefore, it is not necessary to increase the amount of the applied liquid in order to prevent the reaction rate from decreasing due to the reaction. That is,
Since diffusion of oxygen from the ambient atmosphere into the solution can be prevented, the production can be performed with a small amount of the plating solution and the reducing agent, and the production cost is reduced. Further, in order to perform the electroless plating at a temperature higher than room temperature, nitrogen supplied to the gas spray nozzles 6 and 7 may be heated in advance by the heater 22. Thus, the mist liquid is heated to a high temperature, and at the same time, the surface of the glass disk can be heated by the high-temperature nitrogen. In this method, since the treatment liquid is not heated in advance, the life of the treatment liquid is not shortened due to oxidation or the like. Therefore, by supplying high-temperature nitrogen, the treatment liquid and the glass disk 1 can be inexpensively heated to a temperature higher than room temperature, and an electroless plating reaction at a high temperature higher than room temperature can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a nickel electroless plating apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic side view of a nickel electroless plating apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic perspective view of the electroless plating apparatus of FIG.

FIG. 4 is a sectional view of a conventional electroless plating bath.

FIG. 5 is a side view of a conventional electroless plating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Glass disk 2; Glass disk holding member 3; Rotation drive mechanism 4: Arm 5; Arm rotation drive mechanism 6; Gas spray nozzle for plating solution 7; Gas spray nozzle for reducing agent 8; Plating solution pipe 9; Plumbing 10; Plating solution solenoid valve 11; Reducing agent solenoid valve 12; Plating solution filter 13; Reducing agent filter 14; Plating solution tank 15; Reducing agent tank 16; Plating solution nitrogen pipe 17; Nitrogen piping 18; Nitrogen flow control valve for plating solution 19; Nitrogen flow control valve for reducing agent 20; Compressed nitrogen cylinder 21; Diversion control valve 22; Heater 23; Nitrogen piping for plating solution nozzle 24; Nitrogen piping for reducing agent nozzle 25; Nitrogen solenoid valve for plating solution nozzle 26; Nitrogen solenoid valve for reducing agent nozzle 27; Nitrogen filter for plating solution nozzle 28; Nitrogen filter for reducing agent nozzle 29; Nitrogen flow control valve for plating solution nozzle 30; Control flow control valve for reducing agent nozzle 31; Glass disc 32; Plating tank 33; Plating solution 34; Glass disc holding frame 41; Plating solution pipe 42; 43; Plating solution solenoid valve 44; Reducing agent solenoid valve 45; Plating solution filter 46; Reducing agent filter 47; Plating solution pump 48; Reducing agent pump 49; Plating solution tank 50; Reducing agent tank 51; 52; reducing agent piping 53; plating solution solenoid valve 54; reducing agent solenoid valve 55; plating solution filter 56; reducing agent filter 57; plating solution pump 58; reducing agent pump 59; plating solution tank 60; reduction Agent tank 61; plating solution heater 62; reducing agent heater 70; plating solution gas spray nozzle 71; reducing agent gas spray nozzle 72; Liquid piping 73; plating solution for nitrogen pipe 74; reducing agent pipe 75; a reducing agent for the nitrogen pipe 76; nozzle holding member

Claims (6)

[Claims] 1. An apparatus for performing electroless plating on a glass disk (1) having an uneven pattern formed on a glass disk in accordance with a recording signal in order to manufacture a metal master disk of an optical disk, After performing a pretreatment step of activating the surface of the glass disk with a catalyst, the plating solution containing nickel metal ions and the reducing agent are atomized by separate gas spray nozzles (7, 6, 70, 71) to form the glass disk. A nickel electroless plating apparatus characterized by being applied on top. 2. The two gas atomizing nozzles (7, 6, 70, 71) for spraying the plating solution and the reducing agent eject mist-like particles in a straight line. 2. The nickel electroless plating apparatus according to claim 1, wherein the nickel electroless plating apparatus is arranged so that the directions are arranged along the radial direction of the glass disk. 3. The gas spray nozzle according to claim 1, wherein the plating solution and the reducing agent required for the electroless plating reaction are diluted with pure water so as to have substantially the same amount, and each of them is jetted separately in the form of a mist. 3. The nickel electroless plating apparatus according to 1 or 2. 4. The nickel electroless plating apparatus according to claim 1, wherein the gas spray nozzle jets the plating solution and the reducing agent in a mist state using nitrogen. 5. The gas supplied to the gas spray nozzle for spraying the plating solution and the reducing agent in the form of a spray, respectively, is a gas heated to a temperature higher than room temperature.
The nickel electroless plating apparatus according to any one of the above. 6. The nickel-free glass according to claim 1, wherein the glass disk onto which the atomized plating solution and the reducing agent are respectively sprayed rotates at a low speed of about 10 rpm or less. Electroplating equipment.