JPS59185795A - Electroplating method - Google Patents

Abstract

PURPOSE:To improve electrodeposition efficiency and to plate parts to have a uniform plating film by holding parts which are made into a columnar shape and are formed with a hollow hole along the central axis in a plating cell and ejecting a plating soln. into the hollow holes. CONSTITUTION:An inductor core 10 which is completed of electroless copper plating, is subjected to resist printing in the part unnecessary to be formed with electrodes, has a columnar shape and has a hollow hole along the central axis is first pinched between the branch bones 11 of a hooking jig for plating and is dipped in a plating soln. The plating soln. is then injected through an injecting port 15 into the hollow part of the inductor core 10 via a piping 14 for feeding the soln. into a plating cell 7. Then the plating soln. flows out in the direction of the bottom of the cell 7 while flowing vigorously on the conductor surface in the circular cylindrical hollow part. The soln. is thus circulated through a piping 16.

Description

[Detailed Description of the Invention] (Technical Field) The present invention is effective for parts with hollow holes, and provides good plating with excellent appearance, corrosion resistance, electrical properties, and uniformity of plating film thickness. The present invention relates to an electrolytic plating method that allows for.

(Prior art) There is a close relationship between the electrical characteristic no-load loss Qu of the dielectric core and the plating film thickness.
Since u changes, reliable control of the plating film thickness is required to obtain the highest Qu.

Due to the above-mentioned needs, conventionally, the electrodes of the dielectric core used for dielectric filling were formed by brush-painting the inner conductor surface and the outer conductor surface using Ag spray. With this formation method, it is difficult to obtain a desired film thickness in one coating, and several coatings are required, making the process complicated, increasing the number of man-hours and lacking in mass productivity. There was a problem with uniformity.

For this reason, in recent years, electrodes have been formed by shifting to a method of forming electrodes by electrolytic plating, which is highly suitable for mass production. Electrode formation using this electrolytic plating method involves first cleaning and cleaning the surface of the dielectric core.
After roughening and forming a base metal film by electroless copper plating, protect the areas where electrodes are not needed with resist ink, and after electroplating with electrolytic silver, remove the resist ink and base copper film from the areas where electrodes are not needed, and finish with solvent drying to form electrodes. A film was formed.

FIG. 1(,) shows a structural diagram of a dielectric core on which a metal film is formed by the above-mentioned plating method. Figure 1(b) and (
, ) show the cross-sectional structure of A-A and B-B in FIG. 1(a), and the outer conductor surface 1, inner conductor surface 2,
The silver film formed on the top excitation pattern 3 and the bottom surface 6 of the outer conductor is formed into an electrode by a plating method as shown in FIG.

Note that the outer conductor surfaces 4 and 5 are areas where electrode formation is unnecessary, and are surfaces on which resist ink is printed except for the plating process.

FIG. 2 shows the plating bath 7 from the top. The plating hook is placed on the anode plate 8 with the dielectric core 1θ mounted on the jig 9 facing the anode plate 8. During the plating process, the plating hook is fixed. A silver film is formed on the electrode forming portion while the tool 9 swings in the plating solution in the direction of the arrow shown (parallel to the anode plate 8).

However, Fig. 1 (a), (b), (c)
In the case of a component having an irregular structure as shown in (in this case, a columnar dielectric filter with a hollow hole formed along its central axis), the inner conductor surface 2, the outer conductor surface 1, and the outer conductor bottom surface 6 are A problem arises in that the plating film thickness is not uniform.

FIG. 3 shows a cross-sectional view of the dielectric core plated as described above after the silver electrode film is formed. As shown in the figure, the inner conductor is Since the surface 2 has a small diameter, there is no liquid flow, and therefore the electrodeposition efficiency is poor and the plating film thickness is uneven and thin. If the thickness of the plating film on the inner conductor surface 2 is uneven and thin, the quality may be significantly degraded, such as blistering of the plating film after heating and drying, or failure of the electrical properties to be below the standard values. In addition, in order to increase the plating film thickness on the inner conductor surface 2, the plating film thickness can be increased by increasing the plating time, etc., but in that case, the plating film thickness may be increased by increasing the plating film thickness on the outer conductor surface 1 and the outer conductor bottom surface 6. Electrodeposit the precious metal silver, thus cos)
Moreover, if the plating thickness of the bottom surface 6 of the outer conductor is too thick and the diameter of the inner conductor is locally small, problems arise during assembly.

Furthermore, it is possible to improve the electrolytic plating method which has the above-mentioned problems and to make the thickness of the plating film on the inner conductor surface uniform and stabilize the quality by using the following plating method.

FIG. 4, FIG. 5, and FIG. 6 are explanatory diagrams of other electrolytic plating methods.

The plating method shown in FIG. 4 is a method in which the dielectric core 1o is mounted on the jig branch 11 and the auxiliary anode 12 is inserted into the inner conductor of the dielectric core 10. When the diameter of the conductor is small, it is necessary to use a small diameter auxiliary anode 12. Therefore, the auxiliary anode 12 has a diameter of 2-3.
New replacement is required after each plating, and the setting before plating is very complicated, making handling difficult, requiring additional work (man-hours, cost), and making automation impossible. There is a problem.

In addition, in the case of the plating method shown in FIG.
With the plating hook mounted on the jig branch 1, a shield plate 13 (for example, a vinyl chloride plate) is placed on all surfaces of the dielectric core 10 except for the inner conductor surface facing the anode plate 8. This is a plating method that suppresses electrodeposition on the outer conductor and improves electrodeposition on the inner conductor, but the plating hooks must be shielded for each jig.
After manufacturing the dielectric core 10 and plating the dielectric core 10, it is mounted on a jig, the shielding plate is set, and after positioning, plating and removal, which increases the manual work (cost). .

Furthermore, in the case of the plating method shown in FIG. 6, as shown in the cross-sectional view of the plating tank 7, the plating hook is the dielectric core 10 mounted on the branch 11 of the jig 9, and the plating hook is connected to the anode plate 8. There is a method of plating by using a cathode rocker to swing the anode plate in 8 directions during processing, which is mechanically possible in a patch-type manual plating tank, but it is costly due to manual work)
However, automatic plating equipment has problems such as being mechanically complex, expensive, and impractical.

Some of the electrolytic plating methods mentioned above result in an increase in cumbersome manual processes and are difficult to automate.Even if a dielectric core with stable quality can be supplied, the drawbacks still remain unsolved and the number of man-hours increases. This has problems such as high costs due to upgrades and lack of mass production.

(Objective of the Invention) The present invention has been made to eliminate these problems, and provides an electrolytic plating method that forms a uniform electrode film, has high quality, and can be manufactured at low cost. It is.

(Structure of the Invention) That is, this is an electrolytic plating method for parts formed in a columnar shape with a hollow hole formed along its central axis, in which a plating solution is spouted out using a jetting port, for example, a nozzle, and the plating solution is poured into a plating tank. It has a structure that allows for intense internal flow.

This configuration achieves the above objectives. Hereinafter, this will be explained in detail using figures.

(Example) As shown in FIG. 1, in order to form a uniform electrode film using the electrolytic plating method and manufacture a dielectric core with excellent electrical properties, first, the dielectric core is After cleaning and roughening the surface and forming a base metal copper film on the entire surface, parts where electrode formation is not required are protected with resist ink, and after drying and solidifying the resist ink, the electrolytic plating method of the present invention described below is used, This can be obtained by forming electrodes.

FIG. 7 is a diagram showing an embodiment of the electrolytic plating method according to the present invention, and FIG. Piping that sends the liquid to the plating tank 7 (e.g. vinyl chloride pipe),
15 is a plating solution injection port, 16 is a plating solution injection port,
This is a diagram showing the piping that feeds from the plating tank 7 to the 'E filter. In the same figure (b), the plating hook is plated toward the inner conductor surface of the cylindrical hollow part of the dielectric core lθ mounted on the jig 9. It is an enlarged view showing the setting of the liquid injection port 15.

The present invention performs electrolytic plating using a plating apparatus having such a structure, and first, electroless copper plating is completed and the dielectric core 10 is coated with a resist printed on areas where electrode formation is not required.
The plating hook shown in FIG. 7(b) is inserted between the jig branches 11 and immersed in a plating solution, after which electrolytic silver plating is performed.

That is, after the dielectric core 1o is set as shown in FIG. It is injected onto the inner conductor surface of the cylindrical hollow part of the dielectric core 1o. As a result of this injection, the plating solution is flowed out toward the bottom of the plating tank 7 while flowing violently on the inner conductor surface, and is then sucked into the pipe 16 that sends it from the plating tank 7 to the filter, and is filtered through a filter (not shown). It returns to the container. By repeating the above-mentioned operations during the electrolytic plating process, the plating solution on the inner conductor surface of the dielectric core 10 constantly flows out without stagnation, thus improving the electrodeposition efficiency. The film thickness becomes uniform.

If the electrolytic plating method described above is used, the film thickness on the inner conductor surface will be uniformly thicker than the conventional plating film thickness, the bottom surface of the outer conductor will not be locally thick, and there will be no problems during assembly. Moreover, the plating film is electrodeposited uniformly over the entire dielectric core, and there is no blistering of the plating film after heating and drying. It is also possible to solve the fundamental quality problem of fluctuations in electrical characteristics due to non-uniformity of the plating film. Furthermore, the injection port of the plating solution is directed toward the conductor surface inside the cylindrical hollow part of the dielectric core so that there will be no hindrance to the carrier/transport within the plating tank.

By positioning and fixing in a precise manner, an automatic plating line becomes possible, productivity is improved, and man-hours can be reduced.

(Effects of the Invention) As explained above, according to the electrolytic plating method of the present invention, a uniform metal film can be formed by violently flowing the plating solution in the plating tank without increasing the plating processing time. In terms of quality, it has good adhesion, has a high no-load Qu that fully satisfies the standards, exhibits excellent electrical characteristics, and can constitute a dielectric filter with good vibration resistance and impact resistance. or,
Applicability to automatic plating equipment, and the above explanation uses a cylindrical dielectric core with a hollow part as an example; It has sufficient applicability for both punching and uniform plating film thickness, and can be expected to have excellent effects such as improved productivity, countermeasures against yield problems, and cost reduction.

[Brief explanation of drawings]

Figure 1 is a perspective view and cross-sectional view of a dielectric core on which electrodes have been formed, Figure 2 is a top view of a plating tank used in a conventional electrolytic plating method, and Figure 3 is a perspective view and a cross-sectional view of a dielectric core on which electrodes have been formed. 4, 5, and 6 are diagrams showing six other electrolytic plating methods, and FIG. 7 is a cross-sectional view of the dielectric core according to the present invention. and (b) is a sectional view of a plating tank to which the present invention is applied and an enlarged view of the injection port, which is the main part thereof. 1 is the outer conductor surface, 2 is the inner conductor surface, 3 is the top part excitation/4' turn, 4 and 5 are parts where electrode formation is not required, 6 is the bottom surface of the outer conductor, 7 is the plating bath, 8 is the anode plate, 9 is the plating The hook is a jig, 10 is a dielectric core, 11 is a plating hook is a jig branch, 12 is an auxiliary anode, 13 is a shielding plate, 14 is piping, 15 is an injection port, 16
is piping. Figure 1 (01fb) (C) Figure 2 Figure 3 1, Display of the case 1982 Patent Application No. 058793 2 Name of the invention Electrolytic plating method 3 Person making the amendment Relationship to the case Patent Applicant position (
Address: 105) 1-7-12 Toranomon, Minato-ku, Tokyo Name (029) Representative of Oki Electric Industry Co., Ltd.
Director and President Nankai Hashimoto 4 Agent address (105) 1-7-1 Toranomon, Minato-ku, Tokyo
No. 2 No. 6, Contents of the amendment As shown in the attached sheet, Contents of the amendment (1) In the third line of page 2 of the specification, "Electrical characteristics unloaded"
゛Delete "loss amount" from "loss amount QuJ". (2) The phrase "dielectric filter" in the first to second lines of page 4 of the same book is corrected to read "dielectric core." (3) On page 8, line 13 of the same book, the phrase "on jig 9" is corrected to "on jig ramus 11."

Claims (1)

[Claims] A method for electrolytic plating of a columnar part having a hollow hole along its central axis, comprising: a jig for supporting a part to be plated having the shape in an electrolytic plating tank; and the jig. A plurality of injection ports are disposed facing each other, and a part having the shape as described above, on which a base metal film has been formed and the main part of the silver mesh has been treated with resist ink, is supported on the jig and immersed in a plating solution in a plating bath. An electrolytic plating method characterized in that the plating solution is then injected into the hollow hole of the component through the injection port to perform a plating treatment on the inner surface of the hollow hole.