JPH08296093A - Plating device - Google Patents

Abstract

PURPOSE: To prevent one material to be plated being put on another and to obtain a plating device capable of forming a uniform plating film on the surface of the materials. CONSTITUTION: A liq. ejection nozzle 18 is arranged above a cathode 19 consisting of a metallic mesh. An ejection port is formed on the surface of the nozzle 18. A plating soln. from a circulating pump 16 is ejected on the surface of the cathode 19 and reciprocated in the horizontal direction. A material to be plated, on which the plating soln. is ejected from the nozzle 18, is dropped on the cathode 19 surface and firmly attached to the cathode 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus used for electrode layer plating of, for example, ceramic electronic parts, and more particularly to a plating apparatus capable of suppressing variations in film thickness of a plating film formed on the surface of an object to be plated. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, a method of forming a metal plating film using a plating apparatus has been used in the step of forming external electrodes of chip type electronic parts such as multilayer capacitors. In this plating process, many chips are put on the cathode surface,
A metal plating film is formed on a predetermined portion of the chip surface by applying an electric current between the anode and the anode while being immersed in the plating solution.

However, in order to improve the efficiency of the plating process,
When a large number of chips are put on the cathode at one time and plating is performed, inversion and stirring of the chips become insufficient and contact with the cathode becomes poor, which causes a problem of defective plating chips. Therefore, conventionally, in order to prevent defective plating of the chip, methods such as giving a slight vibration to the cathode and reciprocating in the horizontal direction have been performed.

[0004]

However, although the method of giving slight vibration or horizontal vibration to the cathode is effective in reversing and agitating the chips, stacking of the chips is prevented and a good contact state with the cathode is obtained. Is still insufficient to secure. On the contrary, there was a case where chips were newly stacked due to vibration. The chips stacked on the chip lose contact with the cathode and the plating film is not formed. For this reason, there has been a problem that the film thickness of the plating film varies among a large number of chips put on the cathode.

An object of the present invention is to provide a plating apparatus capable of preventing stacking of plated objects and forming a plated film having a uniform film thickness with little variation among the plated objects.

[0006]

A plating apparatus according to the present invention comprises a plating solution tank for storing a plating solution, and an object-to-be-plated container which is immersed in the plating solution with the object to be plated on the surface. And a liquid jet nozzle that is disposed above the placement surface of the object to be plated container on which the object to be plated is placed and that applies a jet flow of the plating solution to the object to be plated that is placed. Is characterized by.

The liquid jetting nozzle is not particularly limited in its shape as long as it has a jetting port for jetting the plating liquid into the plating liquid, and it may be formed in accordance with the planar shape of the object container for plating. Various things can be applied. Further, holes, slits, or those in which a large number of these are arranged can be applied to the injection port.

Further, the plating apparatus according to the limited aspect of the present invention is characterized by further comprising a liquid jet nozzle driving section for moving the liquid jet nozzle along the mounting surface of the object to be plated.

As the drive mechanism for the liquid jet nozzle, a known mechanism such as a mechanism for moving along the guide rail, a mechanism for connecting to a chain or a belt for moving, can be used. Further, the plating apparatus according to the limited aspect of the present invention further comprises a vibration means connected to the object-to-be-plated container and reciprocating the object-to-be-plated container in at least one of a horizontal direction and a vertical direction. It has a feature.

A plating apparatus according to another limited aspect of the present invention is arranged below a container for storing an object to be plated in a plating liquid tank, and jets a liquid jet to the object to be plated through a mounting surface of the container for storing an object to be plated. It is characterized by further comprising a lower injection nozzle for giving.

Further, the plating apparatus according to a more limited aspect of the present invention further comprises an anode immersed in the plating solution tank, in which the object-to-be-plated container is connected to a negative potential to form a cathode. It is characterized by that.

[0012]

The liquid jet nozzle of the plating apparatus according to the present invention jets a jet of the plating liquid to move the object to be plated laminated on the mounting surface of the object-to-be-plated container, thereby breaking the stack of objects to be plated. , Drop on the mounting surface of the object storage container.

Further, by moving the liquid jet nozzle along the mounting surface of the object to be plated, it is possible to more uniformly break the stacking of a large number of objects to be plated mounted on the mounting surface. Further, when horizontal or vertical vibration is applied to the object-to-be-plated container, the attitude of the object-to-be-plated changes due to the vibration causing the object-to-be-plated to be inverted or agitated. In addition to this, when a jet of the plating solution is applied from the solution injection nozzle, the stacked objects to be plated fall on the mounting surface of the plated article container.

Further, the lower injection nozzle disposed below the object-to-be-plated storage container injects a jet of the plating solution from the lower part of the object-to-be-plated storage container to the upper side, and the mounting surface of the object-to-be-plated storage container is placed. A large number of objects to be plated placed on the top are inverted and agitated to change the posture. Then, by jetting a jet of the plating liquid onto the object to be plated from the injection nozzle arranged above the object to be plated container, the stacked objects to be plated are dropped on the mounting surface.

In the electrolytic plating in which the object-to-be-plated container is used as the cathode, the above-described action makes it possible to uniformly contact the object to be plated with the cathode to all the object to be plated. .

In the case of electroless plating, the contact portion between the object to be plated and the object to be plated or the contact area between the objects to be plated is irregularly changed,
The plating solution and the surface of the object to be plated are brought into contact with each other completely and evenly, and a uniform plating film can be formed on the surface of the object to be plated.

[0017]

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

FIG. 1 is a schematic view of the structure of an electroplating apparatus according to the first embodiment of the present invention. In the plating apparatus 10 according to the present invention, a plating liquid tank 13 is arranged inside a frame body 12 having an upper opening. A plating liquid 14 for performing wet plating is stored in the plating liquid tank 13.

The cathode 19 is immersed in the plating solution 14. The cathode 19 is composed of a metal mesh. On the surface of the cathode 19, a large number of chip-type electronic components as objects to be plated are placed. The cathode 19 includes a supporting member 20, which is provided on both ends of the cathode 19 and made of an insulating material.
It is fixed to the lower end of 20. The upper surfaces of the support members 20, 20 are fixed to the connecting member 21.

Further, an anode 25 is immersed in the plating solution 14 at a position facing the cathode 19. Connecting member 2
Cylinders 22, 23, 24 are connected to 1 as vibration means for applying vibration to the cathode 19. The pair of air cylinders 22 and 23 is provided so as to reciprocate the connecting member 21 in the vertical direction, while the air cylinder 24 is provided so as to reciprocate the connecting member 21 in the horizontal direction.

Further, the plating apparatus 10 is provided with a structure for giving a jet flow of the plating liquid to the object to be plated placed on the cathode 19. That is, from the bottom portion of the plating solution tank 13, a conduit 15 for circulating the plating solution is taken out so as to penetrate the bottom plate of the plating solution tank 13 and the bottom plate of the frame body 22, and is connected to the solution circulation pump 16. Further, a conduit 17 is attached to the discharge side of the liquid circulation pump 16. The tip of the conduit 17 is connected to the liquid injection nozzle 18. The liquid jet nozzle 18 has a large number of nozzles, holes, or slits formed on the surface side facing the cathode 19. The liquid injection nozzle 18 has, for example, a hollow cylindrical shape,
It is arranged above the cathode 19 with a distance of several cm. Then, as shown in FIG.
The drive unit of the liquid jet nozzle is configured so that 8 can reciprocate along the surface of the cathode 19. Although the drive unit of the liquid ejecting nozzle is not particularly shown, the liquid ejecting nozzle 18
There are various known mechanisms capable of sliding movement, such as a mechanism for horizontally guiding the upper portion of the liquid injection nozzle 18 using a guide rail or the like, or a mechanism for connecting and moving the liquid injection nozzle 18 with a chain or belt. Things are applicable.

Next, the plating operation of the plating apparatus having the above structure will be described. A large number of objects to be plated are placed on the cathode 19 and immersed in the plating bath 13.
Electric current is applied between the cathode 19 and the anode 25.

First, the air cylinder 24 is driven to vibrate the connecting member 21 and the cathode 19 in the horizontal direction. Next, the air cylinders 22 and 23 are driven to vibrate the connecting member 21 and the cathode 19 in the vertical direction.

Then, the vibrations of the air cylinders 22 and 23 are stopped. After the driving of the air cylinders 22 and 23 is stopped, the liquid circulation pump 16 is operated to start liquid injection from the liquid injection nozzle 18, and the liquid injection nozzle 18 is horizontally reciprocated. The jet of the plating solution ejected from the solution injection nozzle 18 drops the objects to be plated stacked on the object to be plated onto the surface of the cathode 19 without moving the object to be plated that is in proper contact with the cathode 19. The liquid flow is adjusted so that it can be caused. That is, the strength of the liquid jet is adjusted by adjusting the sizes of the slits and openings of the liquid jet nozzle 18, the amount of liquid discharged from the circulation pump 16, and the like. Also, the liquid injection nozzle 1
The moving speed of No. 8 is adjusted to an appropriate speed by observing the falling state of the object to be plated.

During the plating process, the horizontal vibration, the vertical vibration, the vibration stop, and the jetting of the liquid jet are set as one cycle and are repeated at predetermined intervals. The object to be plated placed on the cathode 19 by the above operation has a uniform plating film formed on a predetermined portion.

Further, when the plating liquid is jetted from the liquid jet nozzle 18 to the object to be plated, the concentration gradient due to the diffusion delay of the ions generated in the vicinity of the electrode is improved, and the film formation speed is also improved. A great effect can be obtained when energizing at.

In the above embodiment, not only the air cylinder but also a vibrator, a hydraulic cylinder or the like can be used as the means for applying the horizontal vibration. Further, the means for applying the vertical vibration is not limited to the air cylinder, but a lifting mechanism using a hydraulic cylinder or a cam may be used.

Here, a specific example in which a plating film is formed by using the above plating apparatus will be described. Chip components such as multilayer capacitors are used as objects to be plated, and current density is 2
A nickel plating film was formed on the surface of the chip component at A / dm ² for 20 minutes. The nozzle shape of the liquid jet nozzle 18 was an elongated slit shape with a width of about 1 mm, and the jet flow of the plating liquid was 1 liter / min. Also, the liquid injection nozzle 1
The moving speed of No. 8 was set to 1 cm / sec, and the liquid jet was given for about 15 seconds. The horizontal vibration and the vertical vibration were applied to the cathode 19 for about 15 seconds in total. For comparison, a plating film was formed by a conventional method that does not apply a liquid jet. The results of this experiment are shown in Table 1.

[0029]

[Table 1]

As is apparent from Table 1, in the case of the present invention, the thickness of the plating film is thicker and the variation is greatly reduced as compared with the conventional case. The increase in the film thickness of the plating film indicates that the contact time between the chip component and the cathode 19 has become longer, and the stacking state of the chip components has been eliminated early by applying the liquid jet. I understand. Further, it is shown that a large number of chip components can be evenly contacted with the cathode 19 because the variation of the plating film is reduced.

FIG. 3 is a structural schematic view of a plating apparatus according to the second embodiment of the present invention. The plating apparatus 30 according to the second embodiment is different from the plating apparatus 10 according to the first embodiment in that the air cylinders 22 to 24, which are means for vibrating the cathode 19, are provided below the cathode 19. It is characterized in that a lower jet nozzle 31 is provided.

FIG. 4 is a structural perspective view schematically showing the structure of the lower jet nozzle 31. Lower injection nozzle 31
Is connected to, for example, a hollow box-shaped nozzle body 31a and a conduit 33 for feeding the plating solution into the nozzle body 31a. A large number of ejection ports 32 are provided on the surface of the nozzle body 31a. Then, the plating liquid pressurized and fed into the nozzle body 31 a from the conduit 33 is jetted upward from the jet port 32. The lower injection nozzle 31 is arranged below the cathode 19 with a slight distance. Therefore, the injection port 3 of the lower injection nozzle
The jet of the plating solution ejected from No. 2 is the mesh cathode 19
It works so as to push up the object to be plated placed on the cathode 19 by passing through. Under the action of this jet,
The object to be plated placed on the cathode 19 is inverted or stirred.

Further, in FIG. 3, the liquid jet nozzle 18 used in the plating apparatus 30 has the same structure and operation as those used in the first embodiment. During the plating operation, the plating apparatus 30 repeatedly performs upward liquid injection by the lower injection nozzle 31 and subsequent downward liquid injection by the liquid injection nozzle 18 at regular intervals. The lower jet nozzle 31 causes the cathode 1
After the object to be plated on 9 is inverted and agitated to change the contact portion with the cathode 19, the object to be plated stacked on the object to be plated is sprayed on the surface of the cathode 19 by the liquid jet from the liquid jet nozzle 18. It is dropped to ensure the contact between the object to be plated and the cathode 19. By repeating such an operation, a uniform plating film is formed on the surface of the object to be plated.

The shape of the lower injection nozzle 31 is not limited to the hollow box shape, and any shape can be used as long as it can give a liquid jet flow to the entire object to be plated placed on the surface of the cathode 19. Is not particularly limited.

The structure of the plating apparatus according to the first and second embodiments described above can also be applied to the electroless plating apparatus. That is, the liquid injection nozzle 18 may be provided above the container for the object to be plated that is immersed in the plating liquid. According to this structure, by changing the posture of the object to be plated, it is possible to change the contact portion between the objects to be plated stacked on the object to be plated. The contact state becomes uniform, and a uniform plated film can be formed.

The plating jet nozzle 18 according to the above-described embodiment has been described with respect to a structure in which one nozzle provided with a jet port is reciprocally moved on the cathode surface. For example, a large number of liquid jet nozzles are provided above the cathode 19. It may be arranged so as to perform liquid injection, or may be configured to perform liquid injection intermittently.

[0037]

As described above, the plating apparatus according to the present invention is configured such that the liquid jet nozzle is provided above the object-to-be-plated container and the jet of the plating solution is given to the object to be plated. It is possible to drop the objects to be plated stacked on the objects to be plated and to ensure contact with the objects to be plated container for all objects to be plated. It can be formed uniformly without variation.

Further, in addition to the above-mentioned jet nozzle, a vibrating means for vibrating the container to be plated, or a lower jet nozzle for giving a jet of the plating solution to the plate from the lower side of the container to be plated. By further including the above configuration, the inversion and stirring operations of the object to be plated can be performed more reliably and uniformly, and a more uniform plating film can be formed.

[Brief description of drawings]

FIG. 1 is a structural schematic diagram of a plating apparatus according to a first embodiment of the present invention.

FIG. 2 is a structural schematic diagram in the vicinity of the liquid jet nozzle 18 of the plating apparatus shown in FIG.

FIG. 3 is a structural schematic diagram of a plating apparatus according to a second embodiment of the present invention.

4 is a structural perspective view of a lower jet nozzle 31 of the plating apparatus shown in FIG.

[Explanation of symbols]

 10, 30 ... Plating device 13 ... Plating liquid tank 14 ... Plating liquid 15, 17 ... Conduit 16 ... Liquid circulation pump 18 ... Liquid jet nozzle 19 ... Cathode 22-24 ... Air cylinder 31 ... Lower jet nozzle 32 ... Jet outlet

Front page continuation (72) Inventor Yasunobu Yoneda 26-10 Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd.

Claims (5)

[Claims] 1. A plating solution tank for storing a plating solution, an object-to-be-plated container to be immersed in the plating solution with the object to be plated placed on the surface, and an object to be plated in the object-to-be-plated container A plating apparatus, which is provided above a mounting surface on which an object is mounted, and is provided with a liquid jet nozzle for giving a jet flow of a plating liquid to the placed object to be plated. 2. The plating apparatus according to claim 1, further comprising a liquid jet nozzle driving unit for moving the liquid jet nozzle along a mounting surface of the object to be plated. 3. The vibrating means, further comprising a vibrating means, which is connected to the plated-material storage container and reciprocates the plated-material storage container in at least one of a horizontal direction and a vertical direction. The plating apparatus according to claim 2. 4. A lower injection nozzle, which is disposed below the object-to-be-plated storage container in the plating liquid tank and applies a jet of the plating liquid to the object-to-be-plated through the mounting surface of the object-to-be-plated storage container. The plating apparatus according to claim 1 or 2, further comprising: 5. The container to be plated is connected to a negative potential to form a cathode, and further comprises an anode immersed in the plating solution tank. The plating apparatus according to claim 4.