JP2745892B2 - How to plating small parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for plating small electronic parts such as multilayer chip capacitors and other small parts.

[0002]

2. Description of the Related Art As a method of plating small parts, there is a method generally called barrel plating. FIG. 3 is a perspective view showing a plating apparatus 11 for performing the barrel plating. According to the plating apparatus 11, the appearance is formed in a hexagonal column shape with an insulating mesh, and the inside of a plating container 13 (the mesh state is not shown) in which a cathode rod 12 as a plating electrode is inserted is inserted. Through the opening 15 in which the lid 14 of the plating container 13 is mounted, a small part as a plating object and a steel ball (hereinafter, SB) as a plating auxiliary member are provided.
) (Not shown), the plating container 13 is immersed and set in a plating tank (not shown), and plating is performed in this state. In this case, the plating container 13 is rotated in the direction of arrow A, and inside the plating container 13, a large number of small parts housed therein and S.M. Stirring is performed on B.

However, the plating apparatus 1 described above
In the case of plating small parts by using No. 1, there is a problem that stirring of the small parts becomes uneven. FIG. 4 illustrates the state.
FIG. 4 is a view as viewed in the direction of the arrow Y, showing a section taken along line XX in FIG. As is clear from the drawings, inside the plating container 13 which is rotated in a certain direction indicated by an arrow A, a large number of small parts, which are objects to be plated, and S.T. B is the plating container 1
A passivation layer 16 is formed in the lower part of 3. Then, the fluidized bed 17 (shown by hatching in the figure) is formed only in the surface layer portion. That is, the stirring of the parts and the like is performed only in the fluidized bed 17 which is the surface layer portion, and since the inner layer portion is the immobile layer 16, the stirring is hardly performed at present. is there. As a result, small parts or S.M. B and small parts and S. There may be a problem that plating is performed while B is adhered.

[0004] Further, as described above, the small parts and S.P. Lid 14 for taking in and out B
However, due to the mechanical processing accuracy of the plating container 13 and the lid 14 or the assembling accuracy of the plating container 13 and the lid 14, a slight gap may be generated in a portion where the lid 14 is attached to the plating container 13. It is inevitable. As a result, when the plating container 13 is rotated, small parts (usually several mm × several mm) are formed.
(Or a size of 1 mm or less) itself is caught in such a gap, and plating is performed in such a state. Furthermore, as described above, if small parts that are stuck or pinched are separated or removed in the final stage of plating, the thickness of the plated film will naturally vary. In extreme cases, the worst case is that small parts are not plated at all.

[0005]

In order to solve such a problem, an apparatus for effectively agitating small parts and the like by rotating a plating container in a horizontal direction and simultaneously swinging the plating container in a vertical direction is known. is there. FIG. 5A is a side sectional view showing a plating apparatus 21 using a parts feeder as an example. (B) is a view in the Z direction of (a). That is, as shown in FIG.
The parts feeder head 22 is used as a vibrator, and the basket 24 connected to the vibrator via the vibration transmission rod 23 is vibrated as described above. Further, as shown in (a) and (b), this basket 24 has a blade 2 to be a jam plate.
5 is provided, and the basket 24 is vibrated by the parts feeder head 22, so that the stored small parts and the like vibrate and collide with the blades 25, so that the stirring of the small parts and the like is effective. Will be performed.

However, in the plating apparatus 21, since the processing of the basket 24 is complicated and it is difficult to integrally form the basket 24, it is inevitable to use a retrofitting method for attaching the blades 25 serving as a jammer plate. I can't get it. For this reason, a small groove tends to be formed in the mounting portion inevitably, and there is a possibility that a small part or the like may bite or be caught in the groove portion due to vibration. become.
As a result, a considerable variation naturally occurs in the thickness of the plating film of the small parts.

[0007] On the other hand, there is a plating apparatus 31 in which a basket 24 is not provided with a jamming plate, although the basket 24 is similarly vibrated. FIG. 6 is a side sectional view showing one example of the plating apparatus 31 having an eccentric motor and a vibration source using a spring. In the plating apparatus 31, the eccentric motor 32 is applied with a predetermined eccentric load 33 to generate eccentric vibration energy, and the eccentric motor 32 is supported via springs 34, 34, thereby generating the generated eccentric vibration energy. Is transmitted uniformly to the basket 36 via the vibration transmission rod 35.

FIG. 7 is an explanatory diagram showing the flow trajectory of an object to be plated such as small parts when the basket 36 of the plating apparatus 31 is viewed from above. That is, for the object to be plated, the rotation in the horizontal plane and the stirring by the vertical swing are performed at the same time, and the stirring action is performed almost equally to the object to be plated. A flow trajectory can be obtained. Here, removing the jamming plate from the basket 36 is also effective. Further, since the structure of the basket 36 is simplified because the jammer plate is eliminated, the basket 36 can be integrally processed. Since this eliminates the room for the generation of the groove due to the attachment of the jammer plate, etc.,
There is no need to worry about small parts getting stuck in the groove.

However, such a plating apparatus 31
Also, in the case where the sticking phenomenon occurs between small parts and the like for some reason, it is inevitable that the flow state of the small parts stagnates due to the difference in shape of the small parts. FIG. 8A is an explanatory diagram showing a stagnation state of small parts and the like generated in the basket 36. That is,
This shows a state in which small parts 37 move and stay near the vibration transmission rod 35 located in the center of the basket 36 and near the inner wall around the basket 36. In such a state, the sticking phenomenon between small parts will be further promoted, and as a result, the thickness of the plating film will vary, and in some cases, the worst case of not being plated at all will be caused. It could be.

FIG. 8B is an explanatory view showing one measure for improving the flow of small parts in the basket 36. That is, the blades 38 for forcibly stirring small parts and the like near the vibration transmission rod 35 located in the center of the basket 36 and near the periphery of the basket 36,
39 (three blades are used in the drawing). However, installing the blades 38 and 39 with a gap so that small parts and the like do not bite is difficult to process.
It is not hard to imagine that it is quite difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to provide a plating method for small parts which enables reliable and accurate plating of small parts.

[0012]

SUMMARY OF THE INVENTION According to the present invention, a container provided with a plating electrode accommodates a large number of small parts as an object to be plated and a number of steel balls, while immersing the container in a plating tank. In a plating method of performing plating by swinging in a vertical direction while rotating in a horizontal plane, a vibration generating unit having an eccentric motor as a plating device, a spring supporting the eccentric motor, and vibration generating energy generated by the vibration generating unit And a vibration transmitting unit for transmitting the insulating particles, wherein the vibration transmitting unit is provided continuously at the center of the bottom surface of the container. It is characterized by mixing quantities.

[0013]

According to the above construction, a small number of small parts and steel balls are accommodated in a container provided with plating electrodes. Further, in this container, at least a predetermined number of insulating particles larger than the accommodated small parts are mixed and accommodated.

Then, the container is immersed in the plating tank while the small parts, steel balls, and insulating particles are mixed, and further swung vertically while being swung in the horizontal plane. While maintaining this state, a predetermined plating voltage is applied to the plating electrode provided in the container, and with the lapse of time, a large number of contained small parts are plated.

[0015] In this case, the container performs the above-mentioned motion in the container, so that a large number of small parts and steel balls and a predetermined number of insulating particles contained therein have a mutual interaction. And mixed. And
The steel ball contacts the plating electrode and becomes charged,
Further, the charged steel ball contacts the small part, and the small part is charged. Then, the plating metal dissolved from the plating tank is electrostatically moved and adheres to the surface of the charged small part, and the small part is plated.

On the other hand, due to the insulating properties of the insulating particles, such movement of the container always collides with small parts and steel balls without receiving the above-mentioned electric action at all. For this reason, small parts and steel balls smaller in size than such insulating particles are always imparted with kinetic energy, and do not stay at any place inside the container and do not stick. , There is always flow. As a result, the plating of small parts is stably performed with the passage of time.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a side sectional view showing a plating apparatus 1 for carrying out a method for plating small parts according to the present invention. The plating apparatus 1 includes a plating apparatus main body 2 and
And a plating tank 3. Also, the plating apparatus main body 2
A vibration generating unit 4, a vibration transmitting unit 5 for transmitting vibration energy generated by the vibration generating unit 4 to the other side,
A basket 6 is provided in series with the vibration transmitting section 5 and accommodates small parts which are objects to be plated. Although not shown, the basket 6 is formed in a mesh shape, and its upper surface is open.

The vibration generating section 4 has an eccentric motor 7 and generates an eccentric vibration energy by applying a predetermined eccentric load 8 thereto. The motor support frame member 70 that supports the eccentric motor 7 is connected to a vibration receiving plate 71, and the vibration receiving plate 71 is connected to an outer case 73 of the vibration generating unit 4 by springs 72, 72. In addition, the vibration transmitting unit 5
A part of the vibration transmitting unit 5 and the basket 6 connected to the vibration transmitting unit 5 are connected to the vibration receiving plate 71, and are immersed in the plating tank 3. In this state, the vibration transmitting section 5 and the basket 6 become a cathode electrode section for plating.

According to the above configuration, the eccentric vibration energy generated by the eccentric motor 7 is transmitted to the vibration transmitting section 5 via the vibration receiving plate 71 and further transmitted to the basket 6. In this case, a spring 72 connected to the vibration receiving plate 71,
The eccentric vibration energy is absorbed to some extent by 72, and the fluctuation state of the vibration generating unit 4 is reduced to some extent. As a result, a stable vibration state can be given to the basket 6. As shown in the figure, the basket 6 accommodates a large number of small parts 74, steel balls 75, and insulating particles 76. Since these baskets vibrate stably,
Mix well with stirring. Note that the size of the insulator particles 76 is sufficiently larger than the small parts 74, and the number thereof is appropriately determined according to the size of the basket 6, the vibration state thereof, and the like.

Next, the movement of the small parts 74, the steel balls 75, and the insulating particles 76 in the basket 6 will be described. FIG. 2 is a side sectional view showing a part of the basket 6. The basket 6 contains a small number of small parts 74 to be plated and a large number of steel balls 75. For example, when the small part 74 is a multilayer ceramic capacitor, its specific gravity is 3 to 8, and the specific gravity of the steel ball is around 8. Further, the specific gravity of the insulating material particles 76 with respect to these is about 3 to 6, and the diameter thereof is φ10 to 15 mm. In particular,
In the case of plating a multilayer ceramic capacitor, it is possible to use an alumina ball or an iron ball coated with a silicone resin as an insulating material particle. It should be noted that the shape may be spherical or rectangular.

Next, the movement of small parts and the like will be described. As the basket 6 rotates in the horizontal plane direction and swings in the vertical direction, the small parts 74 and the steel balls 75 housed therein form a fluidized bed which repeatedly flows in the direction of arrow R, that is, from the peripheral portion to the central portion. Form. On the other hand, since the insulator particles 76 have a large diameter, they cannot enter the fluidized bed and tend to stagnate in the vicinity of the vibration transmitting unit 5 located at the center of the basket 6. Therefore,
Small parts 74 and steel balls 75 moving to the center
The fluidized bed composed of the following is crushed by colliding with the insulating material particles 76 and the inner wall surface of the basket 6 and does not stay near the center (the space indicated by the arrow S). Sticking is prevented, and the stirring and mixing are repeated. For this reason, the plating of the small parts 74 is smoothly performed over time.

[0022]

According to the present invention, as a method for plating small electronic parts such as multilayer chip capacitors and all other small parts, a plating container containing a large number of objects to be plated and steel balls is placed in a horizontal direction. Because the plating is performed while swinging vertically and swinging in the vertical direction,
A good stirring and mixing effect on the contents can be obtained, and the object to be plated can be evenly and uniformly plated.

At this time, in the plating container, the insulator particles larger than the small parts to be plated are stirred and mixed together with the small parts and the steel balls, so that the small parts stay in the plating container. Or the parts are stuck together. For this reason,
With respect to a small number of small parts housed in the plating container, all the parts are reliably plated.

The plating apparatus for carrying out the plating method according to the present invention has a simple structure. In particular, the structure of a plating container set in a plating tank is the same as that of a conventional barrel plating apparatus. As there is no need to provide a lid and no need to provide a baffle plate, it is extremely easy to produce, and small parts to be plated are formed in the lid mounting part and in the vicinity of the baffle plate. Inconveniences such as being caught in a gap or the like can be completely eliminated. Therefore, it is possible to further increase the certainty in plating small parts.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a plating apparatus for performing a plating method for small parts according to the present invention.

FIG. 2 is a side sectional view showing a part of the basket in FIG.

FIG. 3 is a perspective view showing a plating apparatus that performs barrel plating.

FIG. 4 is a view in the direction of the arrow Y showing a section taken along line XX in FIG. 3;

FIG. 5A is a side sectional view showing a plating apparatus using a parts feeder. (B) is an arrow view in the Z direction in (a).

FIG. 6 is a side sectional view showing a plating apparatus having an eccentric motor and a vibration source using a spring.

FIG. 7 is an explanatory diagram showing a flow trajectory of an object to be plated.

FIG. 8A is an explanatory diagram showing a stagnation state of small parts and the like generated in a basket in FIG. 7; (B) is an explanatory view showing a countermeasure method for forcibly stirring small parts and the like in the basket.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plating apparatus 3 Plating tank 4 Vibration generating part 5 Vibration transmitting part 6 Basket 74 Small parts 75 Steel ball 76 Insulating material

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuma Tanaka 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Inside Murata Manufacturing Co., Ltd. (72) Yuko Yamaguchi 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto In Murata Manufacturing Co., Ltd. (72) Inventor Shoichi Kawabata 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Prefecture Murata Manufacturing Co., Ltd. (56) References JP-A-3-153898 (JP, A) JP-A 2-61095 (JP, A) JP-A-62-235498 (JP, A)

Claims (1)

(57) [Claims] 1. A container provided with a plating electrode accommodates a large number of small parts as a body to be plated and a large number of steel balls, and while the container is immersed in a plating tank, the container is vertically rotated while turning in a horizontal plane direction. Swinging in the direction, in a plating method of performing plating, a vibration generating unit having an eccentric motor as a plating device,
Generated by the spring supporting the eccentric motor and the vibration generator
A vibration transmission unit for transmitting vibration generation energy;
A structure in which a dynamic transmission part is continuously provided at the center of the bottom of the container
Using the, in said container, a large insulation granules than at least the small part, the plating method of the small parts which comprises causing a predetermined quantity mixed.