JP3286900B2 - Plating method and plating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating method and a plating apparatus, and more particularly to a plating method and a plating apparatus capable of efficiently plating a small object to be plated such as an electronic component.

[0002]

2. Description of the Related Art One of plating methods for plating an electronic component or the like is to use a mesh-like or flat-plate-like material made of a conductive material and also functioning as a cathode electrode. A large number of objects to be plated (electronic components) are placed on the object-to-be-plated supporting means, and the object to be plated together with the object-to-be-plated is immersed in a plating solution provided with an anode electrode. There is a method in which an object to be plated is electroplated by applying a current between the anode electrodes.

However, in a state where the object to be plated is placed on the means for supporting the object to be plated, the means for supporting the object to be plated (cathode electrode)
In the case where plating is performed by continuously energizing between the anode electrode and the anode electrode, the object to be plated and the mesh-shaped or plate-shaped object-to-be-plated object supporting means serving as the cathode electrode are fixed by the plated metal deposited. Also, there is a problem that the objects to be plated are overlapped, and the objects to be plated are not supplied with power, and the variation in the film thickness is increased.

In order to perform uniform plating, an electric current is applied between the support means (cathode electrode) and the anode electrode of the plating object while stirring the plating solution by applying ultrasonic vibration to electroplate the plating object. There is a known way to do this. However, even when plating is performed while continuously applying ultrasonic vibration, a phenomenon occurs in which the object to be plated moves to a stable position and stays at that position, and it is possible to uniformly supply power to each object to be plated. Disappears, causing variations in plating film thickness,
There is a problem that the plating speed is reduced.

There is also known a method in which electroplating is performed on an object to be plated by applying a current between a means for supporting the object to be plated (cathode electrode) and an anode electrode while applying mechanical vibration (oscillation) to the object to be plated. ing. In this method, it is possible to prevent the plating object supporting means, which is the cathode electrode, from sticking to the plating object to some extent, but it is not always possible to sufficiently prevent the plating objects from being stacked, and it is not possible to prevent each plating object from being stacked. In some cases, it is not possible to efficiently and uniformly supply power to the object, which may cause variations in plating film thickness and decrease in plating speed.

The present invention solves the above-mentioned problems, and a plating method and a plating method capable of preventing an object to be plated from sticking to a cathode electrode and efficiently performing plating with a predetermined film thickness. It is intended to provide a device.

[0007]

In order to achieve the above object, a plating method according to the present invention (claim 1) is characterized in that at least a part of a plating object is placed on a plating object supporting means which also functions as a cathode electrode. By placing the object to be plated and the object-to-be-plated together with the object-to-be-plated and immersing it in a plating solution provided with an anode electrode, a current is supplied between the object-to-be-plated and the anode electrode. In the method of performing electroplating on an object to be plated, mechanically vibrating the object to be plated continuously or intermittently at a predetermined timing through the object-to-be-plated supporting means, and the cathode electrode and the anode
Turns on and off the current supply between the electrodes, and intermittently
A current is passed between the electrode and the anode electrode, and the cathode electrode
At the timing when there is no current between the
The plating is performed while intermittently applying ultrasonic vibration to the liquid .

[0008] In the plating method of the present invention (claim 1)
In addition, mechanical vibration is continuously or intermittently applied to the plating object at a predetermined timing through the plating object supporting means which also functions as a cathode electrode, and the cathode electrode and the anode electrode are applied.
Turns on and off the current between the poles and intermittently connects with the cathode electrode.
Energize between the anode electrode and between the cathode and anode electrodes
The plating is performed while intermittently applying ultrasonic vibration to the plating solution at a timing when power is not supplied to the plating solution .
Thus, the object to be plated and the object-to-be-plated object supporting means, which is a cathode electrode, are reliably brought into contact with and separated from each other at a predetermined interval, and stacking and stagnation of the object to be plated are efficiently prevented, and the plating solution is efficiently stirred. Will be able to do it. Accordingly
Thus, it is possible to perform uniform plating efficiently by supplying power uniformly to each of the objects to be plated while preventing the objects to be plated from sticking to the cathode electrode.

In the plating method of the present invention, the ultrasonic vibration is applied to the plating solution. The ultrasonic vibration is transmitted not only to the plating solution but also to the plating object via the plating solution.

The plating method according to claim 2 is characterized in that a vibration having a frequency of 10 Hz or less is applied as the mechanical vibration, and a vibration having a frequency of 1 kHz or more is applied as the ultrasonic vibration.

When a vibration having a frequency of 10 Hz or less is applied as mechanical vibration and a vibration having a frequency of 1 kHz or more is applied as ultrasonic vibration, the object to be plated and the cathode electrode can be reliably brought into contact with and separated from each other. In addition, the plating solution can be efficiently stirred, and uniform and efficient plating can be performed. In addition, frequency 10Hz
The following mechanical vibration was applied because the frequency was 1
If the frequency exceeds 0 Hz, the plating efficiency may be reduced, or the object to be plated may be cracked or chipped. Also,
The reason for applying ultrasonic vibration exceeding 1 kHz is that
If the frequency is less than 1 kHz, the effect of stirring the object to be plated becomes insufficient.

Further, the plating apparatus of the present invention (claim 3) holds a plating tank containing a plating solution, an anode electrode provided in the plating tank, and an object to be plated.
A plating object support unit that also functions as a cathode electrode that contacts the plating object and supplies power to the plating object; and the plating object is continuously or intermittently performed at a predetermined timing via the plating object support unit. Mechanical vibration applying means for providing mechanical vibration, and ultrasonic vibration applying means for intermittently applying ultrasonic vibration to the plating solution at a predetermined timing, and
Energization between the cathode electrode and the anode electrode is turned on and off.
Current is intermittently applied between the cathode electrode and the anode electrode.
And the ultrasonic wave applying means
The stage is not energized between the cathode electrode and the anode electrode
It is configured to apply ultrasonic vibration intermittently at the right timing
It is characterized by having been done.

According to the plating apparatus of the present invention configured as described above, intermittently provides mechanical vibrations continuously or at predetermined timing Rutotomoni, the cathode electrode and the anode electrode
Turn on and off the power supply between the cathode electrode and the anode intermittently.
Apply current between the electrodes and pass between the cathode and anode electrodes.
It is possible to perform plating while applying ultrasonic vibration intermittently at a timing when electricity is not supplied, and the plating method of the present invention is reliably performed, and the object to be plated adheres to the cathode electrode. This makes it possible to perform plating efficiently while preventing the occurrence of plating.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a plating apparatus according to an embodiment of the present invention.

The plating apparatus includes a plating tank 3 for holding a plating solution 1 and a plating object (for example, an electronic component such as a chip type multilayer ceramic capacitor) 2, an anode electrode 4 provided in the plating tank 3, and A mesh-shaped support means 5 for supporting the workpiece 2 placed thereon and also functioning as a cathode electrode for contacting the workpiece 2 and supplying power to the workpiece; Is held in a suspended state and also serves as a power supply path to the plating object support means 5, for example, a support member 6 whose surface is covered with a resin, and a mechanical vibration that vibrates the plating object support means 5 up and down. The apparatus includes an application unit 7 and an ultrasonic vibration application unit 8 that applies ultrasonic vibration to the plating solution 1.

In this plating apparatus, a wire mesh (mesh) member made of a conductive material and having a roughness of 50 mesh is used as the object-to-be-plated supporting means 5.

As the mechanical vibration applying means 7, a vibrating device capable of continuously or intermittently applying a predetermined vibration at a predetermined timing is used. In addition,
There is no particular restriction on the type of the vibration device for giving the mechanical vibration, and various known devices can be used.

Further, the ultrasonic vibration applying means 8 includes:
An ultrasonic vibrator capable of giving a predetermined vibration continuously or intermittently at a predetermined timing is used so that plating can be performed under various conditions .

Further, in the above-mentioned plating apparatus, the power supply between the cathode electrode 5 and the anode electrode 4 can be turned on and off at a predetermined timing.

Electroplating was performed on the external electrodes of the multilayer ceramic capacitor using the plating apparatus described above. In addition,
The conditions are as follows. Plated object: Laminated ceramic capacitor Number: 5000 Dimensions: 2 mm × 1.5 mm × 1.5 mm Plating bath: Ni bath, Watt bath Current density: 2 A / dm ² Mechanical vibration: Vibration direction; Vertical, amplitude: 20 mm, Period: 0.5 sec (frequency: 2 Hz) Ultrasonic vibration: 40 kHz, 500 W One cycle of energization and application of vibration between the cathode electrode and the anode electrode is set to 6 seconds. For example, at the timing shown in FIG. Electroplating was performed for 20 minutes while energizing and applying vibration between the electrode and the anode electrode. FIG. 2 shows that while electricity is supplied between the cathode electrode 5 and the anode electrode 4 during the first three seconds of one cycle, no mechanical vibration or ultrasonic vibration is applied, and during the latter three seconds the cathode electrode 5 FIG. 5 shows a case where the current supply between the anode electrode 4 is stopped and mechanical vibration and ultrasonic vibration are applied.

Further, electroplating was carried out for 20 minutes while changing the conditions for energization between the cathode electrode and the anode electrode and the conditions for giving vibration as shown in Table 1.

With respect to the energization between the cathode electrode and the anode electrode, the first three seconds in one cycle of six seconds are energized between the cathode electrode 5 and the anode electrode 4 and the latter three seconds are not energized. Two conditions were set: (test numbers 1 to 3 in Table 1) and a case where power was supplied throughout the entire cycle (test numbers 4 to 6 in Table 1).

[0023]

[Table 1]

When plating is performed under the above-described conditions, the film thickness (average film thickness), the variation in film thickness σ, and the object to be plated 500
The rate of occurrence of sticking to the cathode electrode per 0 pieces and sticking of the objects to be plated were examined. The results are shown in Table 1. In Table 1, those with asterisks (*, test numbers 2, 3, 4, 5 , and 6) are comparative examples outside the scope of the present invention.

According to Table 1, of the 6 seconds in one cycle, the current was supplied between the cathode and the anode for the first 3 seconds, and the current between the cathode and the anode was stopped for the second 3 seconds. In the case of Test No. 2 in which only mechanical vibration was applied among Test Nos. 1 to 3, one (two) sticking occurred between the objects to be plated.
However, four (four) sticking to the cathode electrode occurred. It was also found that the plating film thickness was as small as 1.6 μm, the plating speed was insufficient, and the variation σ was slightly large at 0.4.

Test number 3 given only ultrasonic vibration
In the case of No.1, no fixation of the objects to be plated occurred, but 5 (5) fixations to the cathode electrode occurred. Also,
Although the variation σ in the plating film thickness was as small as 0.1, the plating film thickness was as small as 1.4 μm, and it was found that the plating speed was insufficient.

On the other hand, in the case of test number 1 (embodiment of the present invention) in which both mechanical vibration and ultrasonic vibration were applied,
No fixation of the plated objects to the cathode electrode and no fixation between the plated objects occurred at all. The plating film thickness is 2.0 μm, the plating speed is high, and the variation σ
Was as small as 0.1.

Of the test numbers 4 to 6 in which current was applied between the cathode electrode and the anode electrode through the entire process of one cycle of 6 seconds, in the case of test number 5 in which only mechanical vibration was applied, in the case of test number 5, the objects to be plated were fixed. 3 (6) occurred, and 20 (20) adhered to the cathode electrode. Further, the plating film thickness is 2.6 μm, which is larger than that of Test No. 2, but the variation σ is slightly larger at 0.7.

Test No. 6 to which only ultrasonic vibration was applied
In the case of (1), only one (two) adhesion occurred between the objects to be plated, but eight (eight) adhered to the cathode electrode. The variation σ in the plating film thickness was as small as 0.2, but the plating film thickness was 2.5 μm, which was small for all the steps.

[0030] In contrast, in the case of mechanical vibration and Test No. 4 gave both ultrasonic vibration, although sticking and fixing the chip to each other to the cathode electrode of the object to be plated was not generated,
Variation in the plating thickness σ was Tsu name as large as 0.6. the above
From the results, it was found that the current was intermittently applied between the cathode and anode electrodes.
Between the cathode and anode electrodes
Imming, both ultrasonic vibration and mechanical vibration in plating solution
Is the best in the case of test number 1 that gives
Is obtained.

In the above-described embodiment, a case has been described in which both mechanical vibration and ultrasonic vibration are simultaneously applied in the latter three seconds of one cycle of six seconds. It is not limited,
For example, as shown in FIG. 3, it is also possible to configure so as to alternately apply both mechanical vibration and ultrasonic vibration.
In that case, the same result as in the above embodiment can be obtained.

For example, one of the mechanical vibration and the ultrasonic vibration may be applied first, and then the other may be applied so that the two overlap. , May be configured to stop one of the vibrations first, and then stop the other vibration after continuing for a predetermined time. Therefore, for example, as shown in FIG. 4, after the current is supplied between the cathode electrode and the anode electrode for the first 2 seconds, the current is stopped, and at the same time, the mechanical vibration is started, and then the ultrasonic vibration is delayed for 1 second. Give a timing chart that overlaps with mechanical vibration, stops mechanical vibration after 5 seconds from the beginning of one cycle, and then continues applying ultrasonic vibration for another second. It is possible.

In some cases, a machine of a suitable size may be used.
It is also possible to configure so as to continuously apply mechanical vibration . Further, it is also possible to configure so that the magnitudes of the mechanical vibration and the ultrasonic vibration are changed on the way.

[0034] As for the timing of the energization of the between the cathode electrode and the anode electrode is not limited to the above embodiment, may be to energize a variety of timing
There is . In addition, from the viewpoint of efficiently removing the adherence between the objects to be plated, it is preferable that the ultrasonic vibration is applied in a state where the power supply between the cathode electrode and the anode electrode is stopped.

Further, in the above-described embodiment, the case where the mesh-shaped support for the object to be plated is used has been described. However, the means for supporting the object to be plated is not limited to this. It is possible to use various kinds of conductive materials such as a plate-like material having holes and a corrugated material.

Further, in the above embodiment, the case where Ni plating is performed on the surface of the external electrode of the multilayer ceramic capacitor has been described as an example. However, the type of the object to be plated is not limited to this. The present invention can be applied to a case where components, multiple substrates, and other various electronic components are plated.

The present invention is not limited to the above-described embodiment in other respects, but relates to the frequency of mechanical vibration and ultrasonic vibration, the type of plating bath, the specific conditions for plating, and the like. Various applications and modifications can be made within the scope of the invention.

[0038]

As described above, according to the plating method of the present invention (claim 1) , the object to be plated which also functions as the cathode electrode is supported.
To the object to be plated continuously or at a predetermined time
To provide intermittent mechanical vibration with
Turns on and off the power supply between the
A current flows between the pole electrode and the anode electrode, and the cathode electrode and the anode
When there is no current between the electrodes,
Plating while applying intermittent ultrasonic vibration
Because there, the object to be plated supported which is the object to be plated and the cathode electrode
Means at a predetermined interval, and
It effectively prevents stacking and stagnation of sticky items, and
It becomes possible to stir the wicking liquid efficiently. I
Therefore, the plating object is prevented from sticking to the cathode electrode.
Power is uniformly supplied to each object to be plated,
It will be possible to do the stick.

Further, when the vibration having a frequency of 10 Hz or less is applied as the mechanical vibration and the vibration having a frequency of 1 kHz or more is applied as the ultrasonic vibration, as in the plating method of the second aspect, the object to be plated and the cathode electrode may be vibrated. Can be reliably brought into contact with and separated from each other, the plating solution can be efficiently stirred, and efficient plating can be performed without variation.

The plating apparatus of the present invention (claim 3) comprises a plating tank, an anode electrode provided in the plating tank,
A plating object support means which also functions as a cathode electrode for contacting the plating object and supplying power to the plating object; and a mechanical means for continuously or intermittently applying mechanical vibration to the plating object at a predetermined timing. a vibration applying unit, with and an ultrasonic vibration applying means for applying intermittent ultrasonic vibrations at a predetermined timing in the plating solution, between the cathode electrode and the anode electrode
Turns on and off the power supply to the
Conduct electricity between the poles and electricity between the cathode and anode electrodes
Do not apply ultrasonic vibration intermittently when not
Therefore, the plating method of the present invention can be reliably performed, and the plating can be efficiently performed while preventing the object to be plated from sticking to the cathode electrode.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a plating apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a timing chart of energization and vibration application between a cathode electrode and an anode electrode in the plating method of the present invention.

FIG. 3 is a diagram showing another example of a timing chart of energization and vibration application between a cathode electrode and an anode electrode in the plating method of the present invention.

FIG. 4 is a view showing still another example of a timing chart of energization and vibration application between a cathode electrode and an anode electrode in the plating method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plating liquid 2 Plating object 3 Plating tank 4 Anode electrode 5 Plating object support means (cathode electrode) 6 Support member 7 Mechanical vibration applying means 8 Ultrasonic vibration applying means

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yoshinori Sakamoto 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto, Japan Inside Murata Manufacturing Co., Ltd. (72) Yasunobu Yoneda 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto, Japan (56) References JP-A-8-296093 (JP, A) JP-A-8-277500 (JP, A) JP-A-63-312996 (JP, A) Jpn. JP, U) JP-B 61-28755 (JP, B2) JP-B 62-1291 (JP, B2) JP-B 61-14237 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , (DB name) C25D 5/20 C25D 5/08 C25D 5/18

Claims (3)

(57) [Claims] 1. A plating solution in which an object to be plated is placed on an object supporting means, at least a part of which also functions as a cathode electrode, and the object is plated together with the object supporting means. In the method of performing electroplating on the object to be plated by applying a current between the object-to-be-plated support means (cathode electrode) and the anode electrode while immersed in the object to be plated, While continuously or intermittently applying mechanical vibration at a predetermined timing, energization between the cathode electrode and the anode electrode is turned on / off.
And intermittently conduct electricity between the cathode electrode and the anode electrode.
And no current flows between the cathode electrode and the anode electrode.
A plating method, wherein plating is performed while intermittently applying ultrasonic vibration to a plating solution during the plating. 2. The plating method according to claim 1, wherein a vibration having a frequency of 10 Hz or less is applied as the mechanical vibration, and a vibration having a frequency of 1 kHz or more is applied as the ultrasonic vibration. 3. A plating tank for containing a plating solution, an anode electrode disposed in the plating tank, and an object for holding the object to be plated and supplying power to the object to be plated in contact with the object to be plated. Plating object support means which also functions as a cathode electrode; mechanical vibration applying means for continuously or intermittently applying mechanical vibration to the object to be plated via the plating object support means; and plating. An ultrasonic vibration applying means for intermittently applying ultrasonic vibration to the liquid at a predetermined timing, and energization between the cathode electrode and the anode electrode is turned on / off.
And intermittently conducts electricity between the cathode electrode and the anode electrode.
And the ultrasonic wave applying means is configured to connect the cathode electrode and the anode electrode.
Ultrasonic vibration intermittently with no power
A plating apparatus characterized in that the plating apparatus is configured to provide the same .