JPH0527715B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method and apparatus for manufacturing striped plating strips that are efficient and economically effective.

[Conventional technology and problems] High reliability is required for electronic component materials such as lead frames for ICs, and it is recommended to plate their bonding surfaces and electrical contacts with expensive precious metals such as gold. It is common. Stripe plating was developed with the aim of plating such precious metals to the minimum necessary extent, saving on materials with limited resources, and reducing costs.

As shown in Figure 3, the conventional stripe plating described above leaves only the plated surface 3 of the plated strip 1 and blocks all other surfaces with a resist agent, masking tape 2, etc. It was common practice to immerse the plate in a plating solution and stir the electrolyte near the surface 3 to be plated.

However, such conventional methods have several problems as described below.

(1) Since areas other than the plated surface are masked using masking tape, a large amount of masking tape is required compared to the size of the plated surface, which inevitably increases the price. Moreover, such masking tape is a consumable item that cannot be reused once it has been used, and cannot be ignored in terms of cost reduction.

(2) Since the plating method involves immersing the plating solution in a plating tank, a large amount of plating solution is carried out, which is uneconomical. Also, the amount of plating liquid used is large.

(3) If a material that has been masked on all surfaces other than the plating surface is allowed to pass through a plating tank or guide rolls, it may break due to burrs on the slit ends of the plating strips during passage. As a result, the plating liquid penetrates through the tear and causes displacement plating.
It may cause poor appearance.

On the other hand, a method of plating using a mechanical mask has been proposed in which no masking tape is used at all, only a mechanical mask is applied, and plating liquid is sprayed onto the surface to be plated. (For example, Jitsukaiaki
50-95414, JP-A-52-74536, JP-A-57-40918) However, in this mechanical mask plating method, at least during plating, the mechanical mask is brought into contact with the plating strips in a stationary state. This method is mainly intended for so-called spot plating, in which the outline of the surface to be plated is defined and a plating liquid is sprayed to selectively plate a part of the plated strip. In the case of stripe plating, it is practically necessary to run the plating strip continuously through the plating bath. For this reason, when stripe plating is performed using the mechanical mask method, the following problems occur, making it even more difficult to put it into practical use.

(1) If the gap between the plating material and the mask material is not completely sealed, the plating solution will ``seep'', making the plating boundary unclear and reducing dimensional accuracy. In the case of stripe plating, since the material to be plated is in a running state, it is very difficult to achieve this perfect seal.

(2) If the plating boundary becomes unclear, it may be necessary to peel off the boundary a little over the entire plating part in order to achieve dimensional accuracy.

(3) In order to avoid the above-mentioned problems, if you try to use a sealing material such as a sealant for a good seal, the material may be damaged by the tightly adhered sealing material, or the sealing material may be worn out. If it becomes large, it tends to result in incomplete sealing.

(4) In order to prevent the above-mentioned scratches from occurring, it is possible to stop the relative movement of the plating material and the sealing material before plating, but in that case, it would be necessary to obtain long plating strips. The work has to be intermittent, and joints are formed at each plated part, making it impossible to maintain dimensional accuracy.

(5) It is extremely difficult to accurately maintain the relative positional relationship between the plated surface of the plated material and the mask while it is being moved, and for this reason, it is difficult to ensure the dimensional accuracy of stripe plating. Can not.

[Object of the Invention] The present invention aims to eliminate the above-mentioned drawbacks of the prior art and provide a method and apparatus for manufacturing striped plated strips with high efficiency at low cost and capable of maintaining high dimensional accuracy. It is something to do.

[Summary of the Invention] That is, the gist of the present invention is to define the outline of the surface to be plated by using a masking tape with the minimum necessary width, while also defining the outline of the surface to be plated by using the side wall and opening edge of the plating tank. A plating work zone is formed in a region including the masked surface to be plated, thereby isolating areas other than the work zone from contact and scattering of plating waves, and reducing the pressure inside the plating tank from the outside of the plating tank. The purpose is to perform plating by jetting plating liquid from a nozzle inside the plating tank and collecting the used plating liquid by suction under the condition that the plating work area is lowered. This makes it possible to easily obtain striped plating strips with extremely good dimensional accuracy while minimizing the consumption of masking tape by eliminating the need for additional masks.

[Examples] The present invention will be described below based on Examples.

FIG. 1 is an explanatory cross-sectional view showing how striped plating strips are manufactured by the method according to the present invention using the apparatus according to the present invention.

Reference numeral 1 denotes a covering strip and 2 a masking tape. In the present invention, the masking tape 2 completely covers the surface other than the covering surface 3, as in the conventional example shown in FIG. Instead, as shown in Figure 2, two masking tapes 2 with a width smaller than the width of the plating strip 1 are used, and the plating surface 3 has a sufficient plating contour. is formed and masked, and no masking is performed on the outer surface of the plated strip 1 other than the required maximum mask surface. The masking tape 2 was originally one piece (at the time of supply), but it was cut just before or after it was pasted on the covered strip 1, and the part that corresponded to the covered surface was cut out to finally be pasted. In this state, there are two pieces. To give one specific example, in Figure 2, the thickness is 0.5mm,
6mm wide, 4μm thick copper strip 1 on 70mm wide coated copper strip 1
When performing silver stripe plating on a strip, the conventional masking tape method uses 30 μm on each side of the strip.
Masking was performed using adhesive-coated plastic tape with a thickness of 80 mm and a width of 80 mm (the part of the masking tape that corresponds to the surface to be covered is cut off immediately before or after pasting), but in this example, one side of the strip was used for masking. It is sufficient to use a tape that is 30 μm thick and 16 mm wide. In addition, as shown in Figure 2, the tape in this case also cuts off the part corresponding to the surface to be covered immediately before or after pasting, and then cuts the tape at 5mm intervals at 6mm intervals.
Make sure there are two strips of tape remaining. In the case of this embodiment, the amount of masking tape used is significantly reduced to 1/10 compared to the conventional example.

In FIG. 1, the opening surface 9, which is the opening edge of the plating tank 6, and the side wall are used to prevent the plating liquid from scattering to the non-mask area. That is, as shown in FIG. 1, the width of the opening surface 9 of the plating tank 6 is configured to be larger than the width of the surface to be plated 3 whose outline is defined by the masking tape 2, and the plating surface is formed along with the opening surface. The side wall of the tank 6 is used to form a work section for plating work.

By the way, it is very difficult to maintain the positional accuracy of the covering strip 1 in the width direction with high precision while traveling in such a work area, and in that sense, as described above, it is difficult to maintain the positional accuracy in the width direction of the covering strip 1. Therefore, the width of the opening surface 9 of the plating tank 6 is configured to be larger than the width of the plating surface 3 whose outline is determined, so that the plating position does not change even when the plating strip 1 moves slightly. In the case of stripe plating, it is very important to ensure dimensional accuracy in the longitudinal direction, especially in actual work. If this is done, the stripe plating and dimensional accuracy will be determined by the adhesion accuracy of the masking tape 2 without being influenced by the opening surface of the plating tank 6.

On the other hand, the plating liquid is supplied by a spraying method instead of the immersion method described above. (In this respect, the known mechanical mask method is directly adopted). That is, the mouth of the nozzle 5 is installed facing the plating surface 3 of the plating strip 1 as shown in FIG.
is injected and supplied from the nozzle 5 toward the surface to be plated 3. At this time, either the nozzle 5 itself is made of metal and used as an anode, or the nozzle 5 is made of an insulating material, and an electrode material is placed in the supply path of the plating solution 4 or in the plating tank 6. The necessary plating can be achieved by using the electrode as the anode and the surface 3 to be plated as the cathode. Here, plating is a soluble anode,
Any method using an insoluble anode may be used.

While the plating liquid 4 is injected and supplied as described above, the used plating liquid that has been supplied is suctioned and collected by the suction and recovery system 8. In this case, air is introduced in the direction of the arrow from the small gap (including the gap that may be formed without special consideration) that exists between the masking tape 2 and the opening edge of the plating tank 6. By doing so, it becomes easy to suction and recover the plating liquid, and it is also possible to reliably prevent the plating liquid from leaking out of the plating tank through the gap. The first method of introducing air is
Either reduce the pressure inside the plating tank 6 as shown in the figure, or
Alternatively, as shown in FIG. 6, by providing a cover 10 and increasing the air pressure inside the plating tank 6.
This can also be achieved by making the external pressure near the masking tape 2 higher than the internal pressure of the plating tank 6. In any case, since the pressure inside the plating tank is lower than the pressure outside the plating tank, the above-mentioned air flow will cause the plating liquid to reach the masking tape 2.
This has a great effect in preventing leakage from between the opening edge of the tacking tank and the opening edge. Further, if an air layer exists between the masking tape 2 and the opening edge of the plating tank, there is no need to worry about accidentally damaging the masking tape 2 when the plating strip 1 travels.

The plating liquid 4 that has been sucked and collected can be separated into gas and liquid, cleaned, and recirculated for use again. This not only eliminates the need for a large amount of plating liquid as in the conventional immersion method, but also improves the plating process. Sufficient plating can be performed using the minimum necessary amount of plating solution without wasting the solution by taking it out.

Furthermore, the nozzle 5 that sprays the plating liquid 4 has four passages instead of one passage as shown in FIG.
As shown in the figure, it is a double nozzle consisting of an inner nozzle 5 ₁ and an outer nozzle 5 ₂ , and is configured into a double passage of an inner passage 5a and an outer passage 5b, one passage is used for spraying plating liquid, and the other is used for spraying plating liquid. If the passage is used for plating liquid suction and recovery, the plating liquid can be quickly replaced with the old and new plating liquid on the plating surface, and new plating liquid can always be supplied to the plating surface. This is useful not only for improving speed but also for significantly improving the quality of the plating layer.

For this reason, the structure of the nozzle 5 is not only made of similar structures for the inner and outer nozzles as shown in Fig. 4, but also has a special structure such as a non-similar structure, which is ideal for stirring the plating solution and replacing old and new solutions. You can also find the configuration.

FIG. 5 shows an improved example of such a nozzle 5, in which a plurality of inner nozzles ₅₁ are accommodated in one outer nozzle ₅₂ . This type of nozzle is installed with the longitudinal direction of the outer nozzle opening aligned with the longitudinal direction of the stripe plating, and by moving the plating strip, new plating liquid is always sprayed from the inner nozzle opening onto the same plating surface. Therefore, even if the running speed of the plated strip is increased, a good plated layer can be formed, which also leads to improvement in mass productivity.

In addition, in the above embodiment, the number of stripes of the striped plating stripes is 1, but the number of stripes is not limited to 1.
It goes without saying that the present invention can also be applied to the production of two or more striped plating strips as shown in the figure.

In the above description, means for supplying plating strips and masking tape, means for pre-processing them, means for adhering them, means for transporting the plated strips masked in this way onto the opening of the plating tank, Further, post-processing means such as peeling off the masking tape are omitted, but these means can be designed and configured in various ways by those skilled in the art to realize the technical idea of the present invention, and are not covered by this invention. This does not in any way hinder the completion of the invention.

Although the pressure roll 7 is shown in FIG. 1, it is capable of moving while ensuring the flatness of the surface 3 to be plated, and is capable of withstanding the spray pressure of the plating liquid to form the plating layer. This is expected to have the effect of improving the quality of the product, and if necessary, a presser plate from the back side having the same effect may be installed.

Furthermore, the meaning of the stripes in the striped plating strips according to the present invention is not limited to stripes in the strict sense. Of course, the concept includes plating patterns formed by moving in the longitudinal direction of a long strip, such as pattern plating in which spot-like or other patterns are formed by punching masking tape.

[Effects of the Invention] As detailed above, according to the present invention, the following excellent effects can be exhibited.

(1) The plating liquid is supplied by a spraying method, which requires less plating liquid when compared to the conventional immersion method, and also limits the plating work area by using the opening of the plating tank. In addition, since plating is performed with the pressure inside the plating tank lower than that outside the plating tank, there is almost no removal of plating solution, so the effect on cost reduction is extremely clear.

(2) The plating device itself can be made more compact and the line length can be shortened compared to conventional methods, which greatly contributes to the effective use of space.

(3) Compared to the conventional immersion plating method, only the minimum amount of masking tape is required, and in addition, the plating work area is limited by the plating tank, which prevents the plating solution from scattering. This further reduces the amount of masking tape used, resulting in a significant cost reduction effect. There are remarkable effects unique to the present invention.

(4) Since masking tape separates the striped plated surface, the dimensional accuracy and clarity of the plated surface can maintain the characteristics of masking tape, and there is no seepage at the boundary like mechanical masking. There is something that can be called revolutionary in the sense that it can accurately plate plated strips that are in a running state without causing any unexpected damage.

(5) According to the present invention, it is not limited to stripe plating in the strict sense, but by punching out masking tape and using it, various pattern plating is possible, and long objects can be manufactured freely. It has the great feature of being able to

[Brief explanation of the drawing]

FIG. 1 is an explanatory sectional view showing an embodiment according to the present invention, FIG. 2 is a sectional view showing a masking method according to the present invention, FIG. 3 is a sectional view showing a conventional masking method, and FIGS. The figure is a partial sketch showing two embodiments of the nozzle according to the present invention, FIG. 6 is an explanatory cross-sectional view showing another embodiment for introducing high-pressure air according to the present invention, and FIG. It is an explanatory cross-sectional view showing another example in the case of two stripe plating. 1: Covering strip, 2: Masking tape, 3:
Surface to be plated, 4: Plating liquid, 5: Nozzle, 6: Plating tank, 8: Suction collection system, 9: Opening surface, 10: Cover.

Claims (1)

[Claims] 1. A masking tape having a width smaller than the width of the plated strip running in the longitudinal direction is pasted, leaving the plated surface of the plated strip running in the longitudinal direction, thereby masking the plated surface. A plating strip with a defined outline of the plating surface is moved over the opening surface of the plating tank via a masking tape, and the pressure inside the plating tank is lower than that outside the tank. A method for manufacturing striped plating strips, in which plating is performed by spraying a plating solution from a nozzle inside a plating tank toward a surface to be plated, and the sprayed plating solution after being used is collected by suction. 2. The manufacturing method according to claim 1, wherein the opening width of the plating tank is formed to be larger than the width of the surface to be plated whose outline is determined by pasting masking tape. 3. Claim 1 or 2, in which the nozzle used for spraying the plating liquid is configured with dual passages, an inner and outer passage, one of which is used for injection and the other one for suction of the plating liquid. The manufacturing method described in section. 4 Claims 1 to 3 in which the nozzle for spraying plating liquid is an anode and the plating strip is a cathode.
The manufacturing method described in any of paragraphs. 5. The nozzle for spraying the plating liquid should be insulated.
5. The manufacturing method according to claim 1, wherein the electrode material disposed in the plating solution supply channel or in the plating tank serves as an anode, and the plated strip serves as a cathode. 6 Consisting of a plating tank and an auxiliary device, the auxiliary device includes a means for supplying a long plating strip and a masking tape having a width smaller than the width of the plating strip, and a means for supplying a long plating strip and a masking tape having a width smaller than the width of the plating strip, and The method includes means for applying masking tape to define the outline of the surface to be plated, means for feeding the applied strip to be plated onto a plating tank, and means for peeling and removing the masking tape after plating, and The plating tank has an opening surface whose outline is larger than the width of the plating surface defined by pasting the masking tape, and an opening surface inside the plating tank with respect to the opening direction. A manufacturing device for striped plating strips comprising a nozzle capable of spouting a plating liquid and a recovery means for sucking and recovering the spouted plating liquid. 7. The manufacturing apparatus according to claim 6, wherein the nozzle is configured with a double inner and outer passage. 8. The manufacturing apparatus according to claim 7, wherein the nozzle has a plurality of inner passages. 9. The manufacturing apparatus according to claim 7 or 8, wherein the cross-sectional shapes of the inner and outer passages of the nozzle are similar. 10. The manufacturing apparatus according to claim 7 or 8, wherein the cross-sectional shapes of the inner and outer passages of the nozzle are not similar.