JPH02159393A - High-speed partial plating device - Google Patents

Abstract

PURPOSE:To form a plating film having a uniform thickness by pressing soluble anodes by springs according to the consumption of anodes to maintain the specified spacing from the material to be plated at the time of shielding the surface of the plate object to be plated with a mask having apertures of a specific shape and subjecting the object to partial plating by using the anodes. CONSTITUTION:The metallic plate to be plated is superposed on the mask 5 having the aperture patterns 6 of the prescribed shape, and a plating liquid is ejected from nozzles 8 through the aperture patterns 6 of the mask 5 to the metallic plate to be plated as a cathode while the plate is kept moved in a specified direction to execute plating in the aperture pattern parts. The soluble anodes consisting of the same metal as the plating metal are used as the anodes 4 in the area of at least twice the area of the plating surface. The anodes are pressed upward by the springs 12 to ascend according to the consumption thereof and are thereby pressed to noncontinuous anode positioning pieces 10 to maintain always the specific spacing with the metallic plate to be plated as the cathode. The aperture pattern-shaped plating is thus formed on the surface of the object to be plated at the uniform thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an improvement in a smooth plating apparatus that performs local partial plating on the surface of a material to be plated.

[Prior Art] As shown in FIG. 4, the basic configuration for plating another metal on the surface of a material to be plated 3 is to fill a plating tank 1 with a plating solution 2, and to deposit the plating solution 2 into the plating solution 2. Placing a soluble electrode 4 made of the same material as the plating material 3 and the metal to be plated,
The material to be plated 3 is used as a cathode, and the soluble type 4E! 4 is used as an anode for electroplating.

In this case, the electrode 4 is gradually eluted into the plating solution 2 at the same time that the surface of the material to be plated 3 is plated by applying electricity, so that the metal ion concentration in the plating solution remains constant even if plating is performed continuously. Since the plating solution 2 is maintained at a constant temperature and the plating solution 2 does not fluctuate over a long period of time, maintenance is relatively easy.

However, although the above method is very convenient for plating the entire surface of the material 3 to be plated, it is not suitable for continuous spot plating locally on the surface of the material 3 to be plated in the form of a long strip. cannot be said to be without problems.

In recent years, for electrical contact materials and lead frames, gold, silver,
Continuous spot plating with nickel or solder has become a practice, which saves plating materials and prevents the formation of unnecessary plating layers on unnecessary surfaces, allowing material properties that suit the purpose. The idea of having people hold the same thing has become popular.

For example, regarding the lead frame, IC1J
It is sufficient that the solder plating is applied only to the G mounting part, and the presence of the solder plating layer on other surfaces is rather undesirable from the viewpoint of conductivity and other properties. Normally, only the IC mounting area is partially plated with solder.

However, if you try to do this using the method shown in Figure 4 above,
As shown in FIG. 3, a mask 5 made of tape on which an open pattern 6.6 corresponding to the plating surface is formed is pasted on both sides of the material 3 to be plated, and this is used for plating between the soluble electrodes 4.4. Continuously pass through the liquid 2 and open the lever 6.
A method must be used in which only 6 parts are plated and then the mask 5 is peeled off.

This method has many disadvantages, such as the positional accuracy of the opening lever 6, the running cost of the tape, and the inability to increase the plating speed.

For this reason, the above-mentioned continuous spot plating uses a plating method in which the plating solution is sprayed onto the plating surface, and plating is performed at high speed with high efficiency so that the plating solution is always in contact with the plating surface, and the quality of the plating layer is improved. It has become common to aim to improve productivity.

[Problems to be Solved by the Invention] In the above plating solution injection method, an insoluble electrode is used as the anode. Therefore, since there is no effect of maintaining the concentration of the plating solution by elution of the electrode 4 as in the case of FIG. 4, new plating solution must be constantly replenished according to the progress of the plating work.

Currently, special plating liquids for this purpose are commercially available from specialized manufacturers.

However, using such a commercially available plating solution not only increases the running cost of the plating solution, but also creates other problems such as making solution management difficult.

Furthermore, these commercially available plating solutions contain special acids that corrode the metal parts of the plating equipment abnormally quickly, causing major damage to the plating equipment within a short period of 2 to 3 years. There are also issues like this.

The purpose of the present invention is to solve the above-mentioned problems in the prior art, and to provide an electrode that can maintain the plating solution concentration by itself in high-speed partial plating using the injection method without relying entirely on conventional commercially available plating solutions. It is an object of the present invention to provide a high-31 partial plating apparatus that can reduce the running cost of the plating solution and facilitate the management of the solution.

[Means for Solving the Problems] The present invention provides an apparatus for plating by circulating a plating solution and spraying the plating solution onto a surface to be plated from a nozzle, in which an anode is installed in correspondence with a cathode material to be plated. It is a soluble electrode that can be dissolved in the plating solution, and by positioning the soluble electrode with a positioning piece and applying a spring force to it, it is possible to maintain a constant distance between the anode and the plating surface. This is what I did.

[Function] If the anode is soluble, the anode will elute and maintain the plating solution concentration in the same way as in conventional basic plating equipment. If the surface of the anode facing the plating surface is always held at a fixed position by the positioning piece, the plating conditions will not change, so that stable plating can be performed at all times.

[Example] The present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory perspective view showing a specific configuration of a plating apparatus according to the present invention.

Reference numeral 5 designates a mask made of an elastic material, for example, and has an opening pattern 6 that plays the same role as that explained in FIG.
The plating solution is sprayed from the opening surface of the open rotor 6 to perform partial plating.

7 is a mask holder that supports the mask 5.

Reference numeral 8 denotes a nozzle opening for spraying the plating solution, and the plating solution supplied under pressure from the plating solution supply passage 9 is injected from the nozzle opening 8 toward the opening rotor 6, and is discharged from the discharge port 13, and is then purified and circulated. I am forced to do it.

4.4 is a dissolvable electrode held within the pedestal 11, and the present invention constitutes its characteristic point. That is, in the conventional nozzle injection type plating apparatus, the anode is made of insoluble material such as graphite, and serves only as an anode on the plating source side with respect to the material to be plated, which is the cathode.

In the present invention, the same material as the metal to be plated is selected for the soluble electrode i4 as in FIG. . As the electrode 4 dissolves into the solution, the concentration of the plating solution is maintained, even though it is a nozzle injection method as explained in FIG. 4.

If the electrode 4 elutes, the electrode 4 itself will be gradually consumed. Therefore, electric 4N! If electrode 4 is in a fixed state, the surface of electrode 4 facing the cathode will gradually retreat due to its wear and the distance between them will increase, and the liquid resistance will increase accordingly, making it difficult to perform the conventional constant voltage plating method. In this case, the plating thickness becomes thinner as the electrode wears out, making it impossible to perform stable plating.

In the present invention, a positioning piece 10.10 is provided for always positioning the opposing surface of the electrode 4 in a constant manner, and a spring 12.12 is arranged on the back side of the electrode 4 to keep the electrode 4 in the position. A spring bias is applied to maintain the pressing force towards the tabs 10°10.

With this configuration, even if the electric current 4f14 is consumed, its opposing surface will always be present at the position of the positioning pieces io, io, and there is no risk of the above-mentioned variation in the plating thickness.

Therefore, it is not preferable to configure the positioning piece 10 so that the entire surface is in continuous contact with the electrode 4. If configured in this way, the electrode will selectively elute from the surface facing the plated surface. Therefore, the opposing surface becomes concave, resulting in an increase in the distance from the plating surface.
This causes the variation in the plating thickness mentioned above. Therefore, as shown in FIG. 1, the positioning piece 10.10 has a shape such as a needle, a cone, or a pyramid that can form an intermittent protrusion so as to contact the electrode 4 discontinuously. It is desirable to have a configuration in which the protrusions touch the surface of the electrode 4 at intervals of about Low. By configuring it in this way,
The facing surface of the electrode 4 can be eluted almost uniformly.6 On the other hand, considering the elution rate of the electrode 4, the following equation is obtained.

Electrode elution rate = AK/AAX plating rate here AK
: Plating area AA: Electrode area When the plating target is solder plating or Ni plating (commonly used plating in lead frames, etc.), the industrial plating speed is usually about 1 to 15 μm/nin. Therefore, assuming full operation 24 hours a day, one electrode
．． This results in consumption of 4 to 21.6 ms+/day. Therefore, if the effective area of the electrode is approximately the same as the plating area, the electrode will be eluted and consumed by the above-mentioned 1.4 to 21.6 nn + thickness in one day of operation.

Since the material to be plated is generally something like a lead frame, considering its size, the thickness of the electrode in the plating apparatus is limited to about 20 AU+. Frequent replacement of electrodes will reduce productivity, and it is desirable to be able to operate continuously for at least one week. Based on this calculation, the effective area of the soluble electrode 4 is equal to the area of the surface to be plated. It is preferable to configure it so that it has at least two values or more, ideally about IO times.

FIG. 2 is an explanatory sectional view showing another embodiment of the present invention.

On the side shown by this solid line, the pedestals 11 and 11- are placed above and below the plating apparatus, and the soluble electrolyte @! 4.4 are also arranged above and below, and both the upper and lower surfaces of the material to be plated 3 are plated at the same time.

In this embodiment, the nozzle opening 8 is only on the lower side, and there is no nozzle on the upper side for spouting the plating solution. However, the material to be plated, such as the lead frame, has already been punched and then plated. This is because the liquid can pass through the punched gap and reach the opposite side, so it is sufficient to have a nozzle on either side.

The injected plating solution is discharged through the outlet 13 shown in the figure and circulated in the same manner as described above. In this case as well, in the same sense as described above, it is desirable that the effective area of the electrode be configured to be at least twice the plating area, preferably about 10 times.

``Effects of the Invention'' As described above, the plating apparatus according to the present invention maintains the same plating position accuracy as in the conventional spot plating method, and maintains its high-speed performance while performing plating solution running. It can reduce costs and save labor in liquid management, and as the field of partial plating is expanding at an accelerating pace, its industrial value can be extremely large.

[Brief explanation of the drawing]

Fig. 1 is an explanatory perspective view of an embodiment according to the present invention, Fig. 2 is an explanatory sectional view of another embodiment, Fig. 3 is an explanatory diagram showing a conventional partial plating situation, and Fig. 4 is a basic plating apparatus. FIG. 2 is an explanatory diagram showing the configuration of. 3: material to be plated, 4: soluble electrode, 5: mask, 6: open lever pattern, 7: mask holder, 8: nozzle opening, 10: positioning piece, 11, it-: pedestal, 12: spring. Foil 1 diagram

Claims (3)

[Claims] (1) A device that exposes only the plating surface of the material to be plated that will serve as the cathode, shields the other surface of the material to be plated with a shielding mask, and sprays the plating solution from a spray nozzle onto the exposed surface of the mask for partial plating. A high-speed partial plating apparatus comprising: an anode disposed in correspondence with the cathode material to be plated; and a soluble electrode capable of being dissolved in a plating solution. (2) On the side of the soluble electrode facing the surface to be plated, there is a discontinuous positioning piece for positioning the electrode, and on the opposite side there is a spring piece that biases the electrode toward the positioning piece. The plating apparatus according to claim 1, further comprising: a plating apparatus having a plating apparatus; (3) The plating apparatus according to claim 1 or 2, wherein the effective area of the soluble electrode is at least twice the area of the surface to be plated.