JP3244334B2 - Chemical plating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a chemical plating apparatus.

[0002]

2. Description of the Related Art A conventional general chemical plating method comprises the following steps. Degreasing-Rinse-Desmut-Rinse-Rinse-Acid dipping-Rinse-Dip degreasing-Rinse-Activate-Rinse-Rinse- -Washing-Washing-Chromate treatment-Water washing-Water washing-Immersion-Drying In the chemical plating step, after a chemical plating solution is built in a chemical plating tank, the solution is heated, for example, to 9%.
Heating to 0 to 95 ° C. is performed to perform plating on the object to be plated such as a metal. At this time, a metal to be plated is deposited on the surface of the plating tank. However, none of them has advantages and disadvantages and satisfactory results have not been obtained. The most common stirring means is circulation stirring by a pump, but there is a problem of poor stirring efficiency, and aeration is an advantageous stirring means,
Since the plating solution tends to be oxidized, it is not preferable particularly for a chemical plating solution in which the temperature of the plating solution is high. Further, in the prior art, a precipitate deposited in the plating solution serves as a nucleus to deposit metal over the entire inner surface of the plating tank, thereby promoting consumption and decomposition of the solution. Therefore, in order to minimize this tendency, the solution in the plating tank is periodically discarded, nitric acid is added to the plating tank, and the metal deposited in the tank is dissolved and cleaned by leaving it for about 24 hours. In the case of nickel plating, this operation must usually be performed once a week.

[0003]

An object of the present invention is to provide a new chemical plating apparatus in which metal to be plated on the surface of a chemical plating tank is not deposited as much as possible.

[0004]

The present invention relates to a chemical plating apparatus characterized in that a baffle plate is provided between an object to be plated and a vibration stirring means in a chemical plating tank.

The vibration stirring means generates vibration at 15 to 60 Hz, preferably 20 to 40 Hz, and transmits vibration from a vibration motor to a vibration plate in a liquid to transmit the vibration to the liquid. This is a newly developed stirring means, the basic concept of which is as disclosed in JP-A-3-275130, and its modified stirring means is disclosed in Japanese Patent Application No. 4-286544 on September 14, 1992. Filed. It is surprising that, when the vibration by the vibration plate is transmitted to the entire system, the vibration of the whole system is promptly homogenized as compared with the stirring by the screw. The same applies to powder and grain systems, and it has been proved by experiments in which colored sawdust is added to sawdust. The amplitude of the diaphragm is 2 to 30 mm, preferably 10 to 15 mm.

The diaphragm may be vibrated uniformly as described in the above-mentioned publication or the specification, but one or two portions of the diaphragm are connected to a vibration axis to vibrate. You can also. In this case, when the liquid tank is rectangular, two vibrating axes may be provided one by one at both ends of one side of the diaphragm, but one vibrating shaft may be provided at the center of the side. Also, one vibration axis may be provided at one corner of the diaphragm. Corners other than the diagonal sides of the side where the vibration axis is attached or corners where the vibration axis is attached are supported by fixed axes. An elastic body on the fixed shaft,
For example, it is preferable to fix the diaphragm via rubber, a spring, an air spring, or the like, but it is also possible to rely on the elasticity of the diaphragm itself. FIG. 4 shows one specific example. Vibration rods 1 and 2 are provided via vibration transmission rods 5 connected to the vibration motor by an arbitrary means. 3,4
The supporting rubber pieces 10, 1 for supporting the vibration of the diaphragm 6
1 is fixed, and the diaphragm 6 is connected thereto. The diaphragm 6
Vibration transmitting rods 1 and 2 with supporting rubber pieces 10 and 11 as fulcrums
The fan is vibrated so as to lift the fan in accordance with the vertical axis. By holding the fan in the tank, it is possible to mix and agitate liquids, powders, granules and the like.

The method of providing the vibration plate in the vibration stirring means is as follows.
It can be roughly divided into three types. (1) A width of 2 to 10 around the periphery of the chemical plating tank
A type in which a large number of diaphragms of about cm are provided vertically (see FIGS. 1 to 3). (2) A type in which one or two diaphragms are provided at almost the entire bottom of a chemical plating tank at the bottom (see FIG. 4). (3) In the center of the chemical plating tank, instead of a propeller agitating blade, a number of upper and lower diaphragms of an arbitrary shape with the same size as or less than the length of the propeller are provided vertically. However, the type (1) is particularly preferable.

FIGS. 1 to 3 show a plating apparatus provided with a vibration stirring means used in the present invention. The vibration stirring means transmits the vibration generated by the vibration motor 21 to the vibration blade groups 24, 24... Via the vibration frame 22 and the vibration bar 23. The vibrating blade group is installed on both sides of the chemical plating tank 25 as clearly shown in FIGS. In order to prevent the vibration from the vibration motor 21 from affecting the tank 25 main body, the vibration frame 22 is attached to a gantry 28 via a spring 26 and a pedestal 27. The vibrating blade may be horizontal, but is preferably mounted with a slight inclination. The degree of the inclination is preferably set at an angle of 0 to 45 °, preferably 10 to 20 ° with respect to the horizontal direction. In this embodiment, the angle is set at 15 °. The width of the vibrating blade is not particularly limited, but the effect is sufficiently exhibited if it is at least about 30 mm. Usually 30-100m
m, preferably about 50 to 80 mm. The interval between the stirring blades is not particularly limited, but is usually 10 to 80 mm, preferably 30 to 40 mm, and in this embodiment, 35 mm.
It was an interval. The positions of the left and right vibrating blades 24 may be the same height, but may be provided at slightly shifted positions. The uppermost vibrating blade is preferably located at a position about 100 mm below the liquid level. If it is provided above this, it slightly varies depending on its amplitude, but it is not preferable because the liquid scatters. The lowest vibrating blade is preferably located at a position about 50 mm above the bottom. The vibrating blade of the present invention had a width of 80 mm, a length of 400 mm, and an interval of 35 mm.

In the present invention, it is necessary to provide a baffle plate on the surface on which the diaphragm exists so that the vibration from the diaphragm does not directly affect the plated object. It is not necessary to provide. The baffle is
It may be a plate provided with a number of holes, that is, a perforated plate. However, the baffle plate of the present invention may be a cylindrical body in which four baffle plates are connected. FIG. 5 shows a vibration means and a baffle plate (including a combination of a baffle plate which is porous and a baffle plate which is not so) when vibration means as shown in FIGS. It is a top view which shows the example of a combination with. FIG. 5A shows four perforated plates 32, 32, 32, between opposed diaphragms 31, 31.
This is a case provided with a square tubular body formed by surrounding a baffle plate of 32, and is the most typical case of the present invention.
FIG. 5 (b) shows a tube formed by surrounding four baffle plates consisting of two porous plates 32, 32 and two non-porous plates 33, 33 between opposing diaphragms 31, 31. FIG. 5C shows a case in which two porous plates 32, 32 are provided between opposed diaphragms 31, 31. FIG. FIG. 5D shows a modification of the case shown in FIG. 5A in which a circular cylinder is formed. FIG. 5E shows a case shown in FIG.
In this case, the surface without the diaphragm is made non-porous. In addition, the upper and lower portions of the cylindrical body in FIG. 5 may be open or closed, whichever.

An object of the present invention is to prevent metal particles from depositing on the wall of a chemical plating tank due to shock or vibration caused by a diaphragm. Metal particles must precipitate on the surface of the body to be plated. In the present invention, a baffle plate is used as a means for solving this inconsistency, but in order to make the chemical plating bath uniform, the chemical plating bath in the container is fluidized to such an extent that metal particles can be deposited to some extent. Is preferred. Therefore, it is preferable that at least a part of the baffle plate is a porous wall. Usually, the effective opening area is 20 to 60%.

The apparatus of the present invention can be used for so-called composite plating in which a large amount of solid fine particles are added to a plating solution and this is co-deposited during plating, as well as metal plating such as zinc, copper, nickel, cobalt, gold or silver. Can also be used advantageously. In the case of composite plating, in order to cause eutectoids in a state where the composite dispersed particles are uniformly dispersed in the plating, it is necessary that the particles are first uniformly suspended in the plating solution. General solid particles have a specific gravity greater than that of the plating solution, and when added to the plating solution, many of them settle. Therefore, in order to keep these dispersed particles in the liquid uniformly and for a long period of time, stirring is necessary.

[0012]

【Example】

Example 1 In a chemical plating tank having a vibration stirrer having a structure shown in FIGS. 2 and 3, vibration stirrers 31 and 31 and baffles 32, 32 and 32 were placed at positions shown in FIG. 32, the plating object 30 is arranged. The vibration motor 21 is 0.4K
W, and the vibrating blade 24 has a width of 80 mm and a length of 4 mm.
Those having a thickness of 00 mm and a thickness of 1.5 mm are attached at intervals of 35 mm. The baffle plate is a quadrangular cylindrical body (the bottom and the lid do not exist) in which four plastic plates are connected. Each of the four baffle plates has a large number of holes with a diameter of about 3 mm, and the opening area ratio is 50%. It is. In order to raise the temperature of the plating bath, ordinary heating means such as an electric heater or a jacket is used. A plating bath consisting of the following solution I was set up in a chemical plating tank made of SUS-316 having the above-mentioned auxiliary facilities,
The substrate was heated to about 95 ° C., and Ni-P plating was performed on an object to be plated of a metal such as iron, copper, a copper alloy, or aluminum. The immersion time of each of the objects to be plated was 2 minutes.
In one plating bath, plating could be continued for 4000 hours or more. Liquid I Liquid II Nickel sulfate 24 g / l 25 g / l Sodium hypophosphite 20 g / l Lactic acid 27 g / l 10 g / l Propionic acid 2 g / l-pH 4.5 5.0

Example 2 The same test as in Example 1 was performed using the above-mentioned solution II as a plating bath. Again, plating for 4000 hours or more was possible in one plating bath.

[0014]

【effect】

(1) In the conventional method, it was necessary to change the plating solution at a rate of about once a week. However, according to the present invention, the number of times of the replacement is greatly reduced. Can be used for twice as long. (2) After the plating solution is replaced, the chemical plating tank must be washed with nitric acid and then with water. Therefore, the reduction in the number of plating solution replacements means that the number of these operations and the amount of nitric acid and water used And the amount of waste nitric acid generated is also reduced. (3) In the case of composite plating, the quality of the product has been greatly improved not only because the service life of the normal solution is extended but also because the non-uniformity due to the precipitation of the solution can be prevented. (4) According to the present invention, the step of passivation (nitric acid) is unnecessary from the step of the chemical plating method described in the section of the prior art, and the chemical plating can be performed in the following steps. Degreasing-Rinse-Desmut-Rinse-Rinse-Acid dipping-Rinse-
Immersion degreasing-water washing-activation-water washing-water washing-electroless plating-
Electroless plating-Rinse-Rinse-Chromate treatment-Rinse-Rinse-Immersion-Dry Eliminates the need to interrupt plating. Even if chemical plating was performed for about 4000 hours or more, there was no metal deposit on the inner surface of the plating tank, and the solution life was greatly extended. (5) The defective rate when the baffle plate is provided is about 1/3 of the plating defect rate when the baffle plate is not provided by only vibration stirring.
Reduced to

[Brief description of the drawings]

FIG. 1 is a top view of a chemical plating apparatus used in an embodiment of the present invention.

FIG. 2 is a side view of the chemical plating apparatus used in the embodiment of the present invention.

FIG. 3 is a side view of another side of the chemical plating apparatus used in the embodiment of the present invention.

FIG. 4 is a perspective view schematically showing a novel vibration stirrer used in the plating method of the present invention.

FIG. 5 is a diagram showing a vibration means and a baffle plate (particularly a porous baffle plate and a non-baffle baffle plate) in the case where vibration means as shown in FIGS. (A) is a top view showing an example of a combination with the above (including a combination), wherein (a) is a case in which a square tubular body formed by surrounding a baffle plate made of four perforated plates is provided between opposed diaphragms. (B) shows a case in which a cylinder formed by surrounding four baffle plates consisting of two porous plates and two non-porous plates is provided between opposed diaphragms, and (c) is a case where (D) a case in which two porous plates are provided between opposing diaphragms.
(A) is a modified example of the case (a) and is a circular cylinder, and (e) is a case of (d) in which the surface without the diaphragm is made non-porous.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibration bar 2 Vibration bar 3 Fixed bar 4 Fixed bar 5 Vibration transmission bar 6 Vibration plate 7 Tank bottom 8 Support rubber piece 9 Support rubber piece 10 Support rubber piece 11 Support rubber piece 21 Vibration motor 22 Vibration frame 23 Vibration Rod 24 Vibrating blade (vibrating plate) 25 Chemical plating tank 26 Spring 27 Pedestal 28 Stand 29 Baffle plate 30 Plated object 31 Vibrating plate 32 Perforated plate (Baffle plate) 33 Non-porous plate (Baffle plate)

Claims (3)

(57) [Claims] 1. A chemical plating apparatus, wherein a baffle plate is provided between an object to be plated and a vibration stirring means in a chemical plating tank. 2. The baffle plate according to claim 1, wherein said baffle plate is a perforated cylindrical body.
The described chemical plating apparatus. 3. The chemical plating apparatus according to claim 2, wherein an opening area occupied by a hole portion of the porous cylindrical body is 20 to 60%.