JPH07286300A - Plating method and device therefor - Google Patents

Abstract

PURPOSE:To provide a plating device capable of automatically and continuously plating many materials to be plated. CONSTITUTION:This plating device 21 consists of the rotary member 23 provided with a transfer line 27 for spirally transferring a material 20 to be plated to the bottom where a plating soln. 26 is stored and discharging the material from the edge of the periphery, a vibrator 25 to vibrate the member 23 and an anode 29 arranged in the soln. 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus and a plating method for forming a plating film on an object to be plated by electroplating, and more particularly to transferring a large number of objects to be plated continuously. The present invention relates to a plating device and a plating method that enable the plating. Further, the present invention can be utilized for plating on various objects to be plated such as metal parts for which it is necessary to form a plating film, but in particular, the plating film is formed on the external electrodes of many chip type electronic parts. It can be suitably used for forming.

[0002]

2. Description of the Related Art In a chip type electronic component such as a multilayer capacitor, one or more plating layers are often formed on an external electrode. Referring to FIG. 1, the structure of the external electrode of the conventional multilayer capacitor and the plating layer formed thereon will be described.

The multilayer capacitor 1 has a structure in which a plurality of internal electrodes 3 to 8 are formed in a sintered body 2 made of dielectric ceramics. External electrodes 9 and 10 are formed on both end surfaces of the ceramic sintered body 2. The internal electrodes 3 to 8 are usually made of Pd, Ag-Pd, Ni or the like, and are used to secure electrical connection between the internal electrodes 3 to 8 and the external electrodes 9 and 10 and to conduct the external electrodes 9 and 10. To improve
The external electrodes 9 and 10 are formed by applying Ag paste or Cu paste and baking.

However, the external electrode 9 made of Ag,
No. 10 causes a solder leaching phenomenon during soldering. Therefore, in order to prevent the solder leaching phenomenon, the first plating layers 11 and 12 made of Ni are formed on the outer surfaces of the external electrodes 9 and 10. Further, Sn is added on the plating layers 11 and 12 made of Ni to enhance solderability.
Alternatively, the second plated layers 13 and 14 made of solder
Is formed.

The first and second plating layers 11 to 11 as described above
Conventionally, 14 is formed by a simple electroplating method. At the time of this electroplating, a plating container called a barrel 15 of a cylindrical type or a polygonal tube shown in FIG. 2 is used. That is, the plating solution 16 and a large number of steel balls 17 and chip type electronic components 18 called media are put in the barrel 15, the cathode 19 is electrically connected to the steel balls 17, and the plating solution is The plating layer was formed by energizing the 16 side as an anode. Actually, plating is performed by immersing the barrel 15 in a plating solution tank (not shown).

By the way, in the plating method using the barrel 15, the plating film is not sufficiently formed on the external electrodes of the chip type electronic component 18 buried below the plating solution 16. That is, in order to surely form the plating film on the external electrodes of the chip-type electronic component 18, the chip-type electronic component 1
8 must be located near the surface of the plating solution 16.
Therefore, the barrel 15 is rotated in the direction of the arrow shown in the drawing to stir the chip-type electronic components 18 inside, and a plating layer is formed on a large number of the chip-type electronic components 18 that have been thrown therein.

On the other hand, in addition to the plating method using the barrel 15, a method in which a large number of chip type electronic components are put into a conductive car, the car is immersed in a plating bath, and the car is used as a cathode for plating. Has also been adopted.

[0008]

However, both the plating method using the barrel 15 and the method of plating a car by immersing it in a plating bath described above are for plating a large number of electronic components by batch processing. That is, a large number of chip-type electronic components are put into the barrel 15 or the cage, and after the plating process is completed, the process of taking out the plated electronic component from the barrel 15 or the cage is repeated to obtain a large number of chip-type electronic components. Was to be plated.

Therefore, the chip-type electronic component is mounted on the barrel 15
The work of putting in and out of the basket was unavoidable, and automation of this process was difficult. Therefore, many chip type electronic components cannot be plated continuously.

The above problem is not limited to the case where the plating film is formed on the external electrodes of the chip type electronic component, and is the same when the plating film is formed on the outer surface of various objects to be plated.

Therefore, an object of the present invention is to form a plated film on a large number of objects to be plated, regardless of batch processing.
It is an object of the present invention to provide a plating apparatus and a plating method capable of continuously plating a large number of objects to be plated.

[0012]

The plating apparatus of the present invention comprises:
At the plating liquid storage portion that is open upward and stores the plating liquid, and at the bottom surface of the plating liquid storage portion, the object to be plated is transferred in a spiral direction by the vibration applied from the outside and is externally exposed at the outer peripheral edge side. A rotary object to be plated transfer / plating member having a rotary transfer path formed so as to be discharged, and an object to be plated is brought into contact with an upper surface of at least the transfer path of the rotary object to be plated / plating member. And a vibrating means that is connected to the rotary object-transferring object-plating member and that vibrates the rotary object-transferring object-plating member. It is a device.

Further, the plating method of the present invention is characterized in that a plurality of objects to be plated are introduced from above the plating solution storage portion of the rotary object transfer / plating member according to claim 1, and the rotary object to be plated. Transferring a plated object ・ Vibration is applied to a plated member to transfer the plated object along the transfer path, and at least the transfer path is used to remove the plated object by using a cathode arranged to contact the plated object. Electroplating,
It is a plating method.

The rotary object transfer / plating member has the above-mentioned specific structure, and this rotary transfer path is, for example, a conventionally known rotary component transfer device, that is, a ball feeder. It is configured by applying. That is, the rotary component transfer device is
The components introduced into the inside by the vibration given from the outside are transferred from the center side to the outer peripheral edge side along the transfer path arranged in a spiral shape, and are discharged on the outer peripheral edge side. The plating apparatus and the plating method of the present invention have the rotary transfer path as in the rotary component transfer apparatus. Therefore, the object to be plated is transferred along the rotary transfer path to the outer peripheral side. Is discharged in.

As the vibrating means used in the present invention, any vibrating source conventionally used as a vibrating source in a rotary component transfer device can be used.

In the present invention, the object to be plated is plated by electroplating, but the anode is not always necessary. That is, the rotary type object to be plated
The anode may be arranged so as to be immersed in the plating solution stored in the plating member, but instead of the anode, a metal ion-containing aqueous solution supply means for supplying metal ions to the vicinity of the object to be plated is arranged in the plating solution. You may.

[0017]

In the plating apparatus and the plating method of the present invention, the object to be plated introduced into the rotary transfer path is transferred in the transfer path while the rotary object to be transferred and the plating member is vibrated. And is discharged to the outside at the outer peripheral edge side. Then, during this transfer step, the object to be plated is plated by electroplating using the cathode.

Therefore, the object to be plated is introduced into the rotary object to be plated / plated member, is plated while being transferred, and is discharged from the rotary object to be plated / plated member after completion of plating. Therefore, a large number of objects to be plated can be continuously electroplated.

That is, according to the present invention, the above-mentioned rotary object transfer / plating object transfer system having a transfer path such as a rotary component transfer device is used.
It is characterized by using a plating member to carry out plating while moving the object to be plated through a rotary transfer path, thereby enabling continuous plating of a large number of objects to be plated.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be clarified by describing embodiments with reference to the drawings.

FIG. 3 is a sectional view showing a plating apparatus according to an embodiment of the present invention. The plating apparatus 21 includes a linear feeder 22, a rotary type object-to-be-plated transfer / plating member 23, an object-to-be-plated discharge conveyor 24, and a vibration device 25.

The linear feeder 22 is provided to supply the object to be plated to the rotary type object transfer / plating member 23. The linear feeder 22 is configured by a conventionally known linear feeder, that is, a member having a linear transfer path and a vibration source that vibrates the member having the transfer path.

In this embodiment, however, the linear feeder 22 is used, but as means for feeding the object to be plated to the rotary type object to be transferred / plating member 23, a large number of objects to be plated such as a belt conveyor are used. It is possible to use a carrying device for carrying the. In addition, a large number of objects to be plated can be transferred and plated by the rotary member 2 without using a transfer device.
It may be supplied from a hopper arranged above the charging section 23a of No. 3 of FIG. Alternatively, an operator may manually insert a large number of objects to be plated from the above-mentioned input part 23a.

In the present embodiment, the linear feeder supplies the monolithic capacitor 20 as an object to be plated.
In FIG. 3, a plurality of multilayer capacitors 20 are conveyed on the linear feeder 22 at a predetermined distance, but in reality, a large number of multilayer capacitors 20 are fed by the linear feeder 22.
It is randomly placed and transported on.

The multilayer capacitor 20 corresponds to the structure of the multilayer capacitor 1 shown in FIG. 1 in which the plating films 11 to 14 are not formed. The rotary object-transferring / plating member 23 has an opening 23b opened upward. The plating liquid 26 is stored in the recess provided in the opening 23b.

A transfer path 27 is provided on the bottom surface 23c of the recess in which the plating solution 26 is stored. The transfer path 27 is configured to transfer the inserted multilayer capacitor 20 when the rotary object transfer / plating member 23 is vibrated. That is, as shown in the schematic plan view of FIG. 4, the transfer path 27 is configured such that the multilayer capacitor 20 is transferred along the illustrated spiral curve A. This transfer path 27 is used for the rotary object transfer / plating member 23.
It is configured by devising the shape of the end face of the recess bottom surface 23c, and is configured in the same manner as a conventionally known rotary component transfer device.

A discharge port 23d is provided at the outer peripheral edge of the rotary object-transferring / plating member 23. The discharge end of the transfer path 27 is connected to the discharge port 23d.
In addition, the above-mentioned component insertion portion 23a is arranged at the central portion when the rotary type object-transferring / plating member 23 is viewed in plan.

At the outlet 23d, the opening 23b is formed.
A discharge plate 28 extending downward from the outer peripheral edge of the discharge plate 28 is provided. Below the tip of the discharge plate 28, the above-described object discharge conveyor 24 is arranged. The conveyor 24 can be configured by an appropriate transfer device such as a belt conveyor, or like the linear feeder 22 described above, a component transfer device that can linearly transfer the multilayer capacitor 20 by externally applying vibration. It may be configured by.

Next, a configuration for carrying out plating on the rotary type object to be plated / plating member 23 will be described.
An anode 29 is arranged in the plating solution 26.
As shown in FIG. 5, the anode 29 has an opening 29a at the center in this embodiment. The opening 29a is for the multilayer capacitor 2
It is provided so as not to hinder the input of 0 into the transfer path 27 from the input section 23a. Therefore, unless the operation of charging the multilayer capacitor 20 from the central charging unit 23a to the transfer path 27 is disturbed, the shape of the opening 29a is
The shape is not limited to the illustrated circle and may be changed to an appropriate shape. Further, in the present embodiment, the anode 29 has the circular opening 29a and the outer peripheral edge is also circular, but the outer shape of the anode 29 is not limited to the circular shape, but may be changed to an appropriate shape such as a rectangular shape. You can

Further, the anode 29 does not necessarily have to be composed of a single member as shown in the figure, and a plurality of anodes may be arranged in the plating solution 26 at a predetermined distance. Further, although the anode 29 is used in this embodiment,
Instead of the anode 29, a metal ion aqueous solution containing metal ions to be plated on the external electrode of the multilayer capacitor 20 is supplied to the position where the anode 29 is provided, that is, in the vicinity of the multilayer capacitor 20 in the transfer path 27. By doing so, the anode 29 may be omitted. Such means for supplying the metal ion aqueous solution may be configured by disposing a metal ion supply container and a conduit extending from the pump above the transfer path 27.

On the other hand, the rotary type object transfer / plating member 23 is made of stainless steel, Cu, Al,
It is made of a metal such as Ni having a relatively excellent corrosion resistance. In other words, since the plating bath is acidic, the metal that has excellent corrosion resistance as described above can be used to transfer rotary objects to be plated.
It is preferable to configure the plated member 23.

Further, in this embodiment, the rotary object-transferring / plating member 23 also functions as a cathode. That is, since the rotary type object-transferring / plating member 23 is made of metal and has conductivity, as shown schematically in FIG. The material transfer / plating member 23 functions as a cathode, and the multilayer capacitor 20 is electroplated due to the potential difference between it and the anode 29.

However, in the rotary type object-transferring / plating member 23, the upper surface of the transfer path 27, that is, the bottom surface 2
The multilayer capacitor 20 is brought into contact with the upper surface of the part of the transfer path 27 that constitutes the transfer path 27. Therefore, only the portion of the multilayer capacitor 20 in contact with the external electrode needs to function as the cathode. Therefore, it is not always necessary that the entire rotary object-transferring / plating member 23 is made of a conductive material. For example, the rotary object to be plated transfer / plating member 23 may be made of an insulating material such as synthetic resin. In that case, the bottom surface 23c is covered with C.
It may be coated with a conductive material such as u, Al or stainless steel, or the conductive material layer as described above may be provided on the bottom surface 23c only in the portion forming the transfer path 27.

The recess in which the plating solution 26 is stored has a considerably deeper depth than that of a rotary type component transfer device used as a normal parts feeder, so that a sufficient amount of the plating solution can be obtained. 26 is preferably stored.

Further, the vibration device 25 shown schematically in FIG.
Can be constituted by an appropriate vibration source conventionally used in a rotary component transfer device, such as an electromagnet type vibration.

Next, the plating method of the present invention will be explained more concretely by explaining concrete experimental examples.
The outer diameter of the multilayer capacitor 20 is 2.0 × 1.2.
There was prepared a product having a size of 5 × 1.0 mm and having external electrodes formed on both end faces. This multilayer capacitor 20
A Ni plating film was formed on the external electrodes of the above using the plating apparatus 21 of the above-described embodiment. The rotary type object transfer / plating member 23 used is placed at the center of the opening 23b.
a, the diameter of the opening 23b is 300 mm, the depth of the portion where the plating liquid 26 is stored is 20 mm in the portion indicated by the arrow B in FIG. 3, and 3 in the portion indicated by the arrow C.
It is 0 mm, and the plating solution 26 has a Watt bath of 1.0 mm.
I prepared the one that was stored in liters. Also, the anode 2
9 is made of Ni and has an inner diameter of 25 mm and an outer diameter of 50 m.
A Ni plate with m and a thickness of 2 mm was used.

The temperature of the plating solution 26 is set to room temperature, and a large number of multilayer capacitors 20 are inserted from the linear feeder 22 into the charging section 23.
Then, the laminated type capacitor 20 was charged into the apparatus a, and vibration was applied to the rotary type object to be plated / plating member 23 by the vibration device 25, and the charged multilayer capacitor 20 was transferred as indicated by an arrow A in FIG. At the time of this transfer, a voltage of 1 V was applied between the anode 29 and the rotary-type plated object transfer / plating member 23, and the external electrodes of the multilayer capacitor 20 were electroplated.

The multilayer capacitor 20 has a loading portion 23a.
Then, it moved to the discharge port 23d in about 5 minutes, and the plating film was formed by applying the above voltage during that time. The thickness of the obtained plated film was measured and found to be 1.2 μm.

Further, as in the above experimental example,
Instead of the multilayer capacitor 20, N
Using the laminated capacitor having the i-plated film formed thereon, and using the tin sulfate plating solution as the plating solution, the anode was changed from the Ni plate to the Sn plate, and Sn plating was performed in the same manner as above.
As a result, it was confirmed that the Sn plating film having a thickness of 4 μm was formed during the discharging from the charging part 23a to the discharging port 23d (that is, for about 5 minutes).

In the conventional barrel plating, Sn having the above film thickness is used.
It took about 50 minutes to form the plated film, whereas in this example, the Sn plated film having a thickness of 4 μm was formed in about 5 minutes as described above. Therefore, it can be seen that the plating apparatus of the present embodiment can form a plating film having a desired film thickness in a shorter time than the conventional barrel plating.

It was confirmed that the Sn plating film formed as described above has the same solderability and solder corrosion resistance as those of the Sn film formed by conventional barrel plating. Further, as described above, the Ni plating film and the S
It was also confirmed that the electrical and mechanical characteristics of the multilayer capacitor having the n-plated film formed were equivalent to those obtained by conventional barrel plating.

In order to make the thickness of the plated film more uniform, the object to be plated being transferred may be rolled in the transfer path 27. This rolling is performed by providing a mechanism for temporarily blocking the transfer path 27 at a predetermined timing, increasing the intensity or amplitude of the vibration given from the vibrating device 25, or another vibration from another vibration source. Can be caused by giving.

[0043]

According to the plating apparatus and the plating method of the present invention, while the object to be plated is transferred in the rotary transfer path of the rotary object to be transferred and the plating member, electroplating is performed therebetween. This rotary type object-to-be-plated transferring / plating member transfers a part by being vibrated like a conventionally known rotary part transferring device.
Therefore, unlike a batch-type plating method such as a conventional barrel plating method or a plating method using a basket, a large number of objects to be plated can be continuously plated. That is,
Rotary type object transfer ・ Putting the object on the plating member, and applying the vibration as described above, the object to be plated by electroplating while transferring,
Rotating object to be plated and discharged from plating member. Therefore, the plating process can be easily automated.

Moreover, as is clear from the above experimental example,
Compared with the conventional plating method using a barrel, the time required for plating can be greatly shortened when forming a plating film having a similar film thickness.

Further, according to the present invention, the object to be plated transferred in the rotary transfer path of the rotary object to be plated and the plating member is subjected to some braking action by the plating solution so that adjacent objects to be plated are Contact does not cause insufficient plating. However, even if the objects to be plated come into contact with each other and are transferred, there is essentially no problem in the plated state.

Therefore, according to the plating apparatus and the plating method of the present invention, a plating film having a desired film thickness can be formed in a shorter time, and automation of the plating process can be promoted.

[Brief description of drawings]

FIG. 1 is a sectional view of a multilayer capacitor for explaining an example of an object to be plated.

FIG. 2 is a partially cutaway perspective view for explaining a conventional plating method using a barrel.

FIG. 3 is a sectional view for explaining a plating apparatus according to an embodiment of the present invention.

FIG. 4 is a schematic plan view for explaining a transfer direction of an object to be plated in the plating apparatus of the embodiment.

FIG. 5 is a plan view of a rotary type object-transferring / plating member.

[Explanation of symbols]

 20 ... Multilayer capacitor (object to be plated) 21 ... Plating device 22 ... Linear feeder 23 ... Rotary type object transfer / plating member 25 ... Vibration device 26 ... Plating liquid 27 ... Transfer path 29 ... Anode

Claims (2)

[Claims] 1. A plating solution storage section which is open upward and stores a plating solution, and an object to be plated is transferred in a spiral direction by vibration applied from the outside in a bottom surface of the plating solution storage section, A rotary-type object transfer / plating member having a rotary transfer path formed so as to be discharged to the outside on the outer peripheral side, and an upper surface of at least the transfer path of the rotary object-transfer object / plating member. A cathode arranged to contact the plated object; and a vibrating means connected to the rotary object to be plated / plated member and vibrating the rotary object to be plated / plated member. Plating equipment characterized by. 2. The rotary type object transfer / plating member according to claim 1, wherein a plurality of objects to be plated are charged from above the plating solution storage portion of the rotary type object transfer / plating member. A plating method, wherein an object to be plated is electroplated by using a cathode arranged to contact the object to be plated at least in the transfer path while transferring the object to be plated along the transfer path by applying vibration.