JP2005146397A - Method for manufacturing electronic component and plating apparatus used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electronic component, which effectively stirs the component to be plated and an energization medium, and uniformly plates the component to be plated; and a plating apparatus therefor. <P>SOLUTION: This manufacturing method comprises accommodating an element 10 of the electronic component and a medium 19 for energization in a vessel 14 provided with a cathode 17; immersing the vessel in a plating liquid; and while giving the vessel 14 such a motion as to make a moving trajectory of the vessel 14 approximately circular without rotating the vessel 14 itself, by using a driving force of a driving means 13 with the use of a vibration motor 11, and changing the flow condition of the element 10 of the electronic component and the medium 19 for energization in the vessel 14, by periodically changing a frequency of an electrical current fed to the vibration motor 11, passing an electric current to the cathode 17 in the vessel 14 to plate the element 10 of the electronic component. The manufacturing method also comprises changing a ratio of a generated horizontal rotation flow to a generated vertical rotation flow, by periodically changing the frequency of the electrical current fed to the vibration motor 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic component manufacturing method and a plating apparatus, and more specifically, for example, plating an electronic component having an external electrode formed on the surface of a ceramic element (electronic component element) such as a chip-type multilayer ceramic capacitor. It is related with the manufacturing method of an electronic component which is manufactured through the process of giving plating and forming a plating film on the surface of an external electrode, and the plating apparatus used for it.

  One of typical chip-type electronic components is a multilayer ceramic capacitor as shown in FIGS. In this multilayer ceramic capacitor, a plurality of internal electrodes 3 are disposed so as to face each other with the ceramic layer 2 interposed therebetween, and one end side of each of the multilayer ceramic capacitors is alternately drawn out to the end faces of different sides, It has a structure in which a pair of external electrodes 4 are disposed so as to be electrically connected to the internal electrodes 3. The external electrode 4 is formed by applying, drying and baking a conductive paste containing Ag powder as a conductive component, and the surface of the external electrode 4 is Ni-plated to prevent soldering of the Ag electrode. An Sn plating film 6 for improving the film 5 and solderability is formed.

As a method of forming a plating film on the external electrode as in this multilayer ceramic capacitor, for example, there is a method of forming a plating film on the external electrode using a plating apparatus as shown in FIGS. 4 (a) and 4 (b). Are known.
The plating apparatus used in this method includes a vibration motor 51, an eccentric load 52 for applying an eccentric load to the vibration motor 51, a motor support frame member 53 that supports the vibration motor 51, a vibration receiving plate 54, and a vibration receiving plate 54. A vibration generating means 56 having a spring 55 for supporting the metal, an electronic component element (part to be plated) 10 and a current-carrying medium (metal ball medium) 19 as a current-carrying medium are accommodated. A container 57 made of a material that allows liquid to pass through, and a rod-shaped container holding member 58 having a lower end side holding the container 57 and an upper end side connected to the vibration generating means 56. A cathode (not shown) is disposed on the bottom surface.

  In this plating method (apparatus), as shown in FIGS. 4A and 4B, the electronic component element 10 and the energizing medium (metal ball medium) 19 are provided so that the electronic component element can be sufficiently stirred. At the same time, the stirring medium (insulator particles) 20 is added to the container 57, and plating is performed while the container is vibrated. (Patent Document 1).

  In this plating apparatus, as described above, the electronic component element 10 and the energizing medium 19 are added to the container, and the agitating medium (insulator particles) 20 is added to the container 57. It becomes possible to effectively stir the plated product.

  However, depending on the size and amount of the insulator particles 20, the insulator particles 20 may flow together with the electronic component element 10 and the current-carrying media 19, or the insulator particles 20 themselves may stay and The flow of the component element 10 and the energizing medium 19 may be hindered, and the electronic component element 10 or the electronic component element 10 and the energizing medium 19 may be attached (attached).

Further, when the flow of the electronic component element 10 and the energizing medium 19 is hindered, the contact state between the electronic component element 10 and the energizing medium 19 in the container 57 varies, and the energization to the external electrodes becomes uneven. The film thickness of the plating film varies.
Therefore, the size and amount of the insulator particles 20 must be appropriately set according to the size and amount of the electronic component element 10 and the energization medium 19, resulting in a problem that the process becomes complicated and productivity is lowered.
Japanese Patent Laid-Open No. 5-70999

  The present invention solves the above-mentioned problems, and applies a plating method that can effectively stir electronic component elements and energizing media and can uniformly plate electronic component elements. Then, for example, an electronic component having an external electrode formed on the surface of a ceramic element (electronic component element) such as a chip-type multilayer ceramic capacitor is plated to form a plating film on the surface of the external electrode. It is an object of the present invention to provide an electronic component manufacturing method capable of efficiently manufacturing an electronic component manufactured through a process and a plating apparatus used therefor.

In order to solve the above problems, a method for manufacturing an electronic component of the present invention (Claim 1) includes:
The electronic component element and the energizing medium are housed in a container equipped with a cathode, immersed in a plating solution, and the container itself is not rotated by the driving force of the driving means using a vibration motor, and the locus of movement of the container is substantially A circular motion is applied to the container, and the frequency of the current supplied to the vibration motor is periodically changed to periodically change the flow state of the electronic component element and the energizing medium in the container. On the other hand, the method includes a step of energizing the cathode in the container and plating the electronic component element.

The method for manufacturing an electronic component according to claim 2
The container is substantially cylindrical with a bottom, and is supported by a container holding member at a substantially central portion of the bottom wall, and the driving force of the driving means is transmitted to the container via the container holding member. As well as
Regarding the flow state of the electronic component element and the energization medium in the container, a flow that draws a substantially circular trajectory along the circumferential direction of the container when the container is viewed in plane is a lateral rotation flow, the container holding member, When the region defined by the side wall and the bottom wall of the container is viewed in a vertical cross section, the flow that draws a substantially circular trajectory along the substantially circumferential direction of the region is a vertical rotation flow, and is supplied to the vibration motor. It is characterized in that the generation ratio of the transverse rotational flow and the longitudinal rotational flow is changed by periodically changing the frequency of the current to be generated.

  According to a third aspect of the present invention, there is provided a method of manufacturing an electronic component, wherein the frequency of the current supplied to the vibration motor is periodically changed to change the flow state of the electronic component element and the energizing medium in the container. It is characterized in that it is alternately switched between a flow state mainly composed of the above and a flow state mainly composed of longitudinal rotation flow.

The plating apparatus of the present invention (Claim 4)
A container for storing an electronic component element and a current-carrying medium;
It is a driving means using a plating tank for storing the plating solution in which the container is immersed and a vibration motor, and the container itself does not rotate, and the movement of the container moves in a substantially circular shape. Driving means configured to periodically change the flow state of the electronic component element and the energization medium in the container by periodically changing the frequency of the current supplied to the vibration motor while being supplied to the container It is characterized by comprising.

Moreover, the plating apparatus of claim 5 comprises:
The container is substantially cylindrical with a bottom, and is supported by a container holding member at a substantially central portion of the bottom wall, and the driving force of the driving means is transmitted to the container via the container holding member. As well as
The drive means periodically changes the frequency of the current supplied to the vibration motor, so that when the container is viewed in plan with respect to the flow state of the electronic component element and the energizing medium in the container, A flow that draws a substantially circular trajectory along the circumferential direction is a lateral rotational flow, and when the region defined by the container holding member, the side wall and the bottom wall of the container is viewed in a vertical cross section, the flow is substantially in the circumferential direction of the region. When the flow that draws a substantially circular locus along the vertical rotation flow is a vertical rotation flow, the generation ratio of the horizontal rotation flow and the vertical rotation flow can be changed.

  The method of manufacturing an electronic component according to the present invention (Claim 1) is, for example, in manufacturing an electronic component manufactured through a step of plating an external electrode formed on the surface of an electronic component element. The component element and energizing medium are housed in a container equipped with a cathode, immersed in a plating solution, and the container itself does not rotate by the driving force of the driving means using a vibration motor, and the locus of movement of the container is substantially circular. In addition to periodically changing the frequency of the electric current supplied to the vibration motor, the flow state of the electronic component element and the energizing medium in the container is changed periodically, Since the electronic component element is plated by energizing the cathode inside, it becomes possible to efficiently stir the electronic component element and the energizing medium in the container. In such a state, the plating is performed by energizing the cathode, thereby preventing the occurrence of adhesion between the electronic component elements or between the electronic component element and the current-carrying media, and uniform plating on the electronic component element. A film can be formed.

Therefore, for example, a step of plating an electronic component having an external electrode formed on the surface of a ceramic element (electronic component element), such as a chip-type multilayer ceramic capacitor, and forming a plating film on the surface of the external electrode Thus, it is possible to efficiently manufacture electronic components that are manufactured through the process.
In addition, in the manufacturing method of the electronic component of the present invention, it is possible to perform plating by adding not only the electronic component element and the energization medium but also the agitating medium (insulator particles) to the container. It is possible to further improve the stirring effect.

  Further, as in the method of manufacturing an electronic component according to claim 2, the container has a substantially cylindrical shape with a bottom, and is supported by a container holding member at a substantially central portion of the bottom wall, and the driving force of the driving means is the container holding member. And a substantially circular locus along the circumferential direction of the container when the container is viewed in plan with respect to the flow state of the electronic component element and the current-carrying medium in the container. The flow drawn is a horizontal rotation flow, and when the region defined by the container holding member, the side wall and the bottom wall of the container is viewed in a vertical cross section, the flow that draws a substantially circular trajectory along the substantially circumferential direction of the region is vertically rotated. When it is configured to change the generation ratio of transverse rotational flow and longitudinal rotational flow by periodically changing the frequency of the current supplied to the vibration motor, the electronic components in the container Element and communication It is possible to easily and reliably change the flow state of the electronic media periodically, and to maintain a uniform contact state between the electronic component element and the energizing media, and form a uniform plating film on the electronic component element It becomes possible.

  Further, as in the method of manufacturing an electronic component according to claim 3, by periodically changing the frequency of the current supplied to the vibration motor, the flow state of the electronic component element and the energizing medium in the container is changed to the transverse rotational flow. When the flow state is mainly switched to the flow state mainly consisting of the longitudinal rotation flow, the flow state of the electronic component element and the energizing medium in the container is changed regularly and sufficiently, and more Good agitation can be realized, and the contact state between the electronic component element and the energization medium can be kept uniform, and a plating film having a uniform film thickness can be reliably formed on the electronic component element.

The plating apparatus of the present invention (Claim 4) is a drive unit using a container for storing an electronic component element and a current-carrying medium, a plating tank for storing a plating solution in which the container is immersed, and a vibration motor. In addition, the container is provided with driving means for giving the container a motion that makes the trajectory of the container move substantially circular without rotating the container itself, and periodically changing the frequency of the current supplied to the vibration motor. Since the flow state of the electronic component element and the energization medium in the container can be periodically changed by the operation, the electronic component element and the energization medium can be efficiently stirred in the container. Is possible. Therefore, it is possible to form a plating film having a uniform film thickness on the electronic component element while preventing the electronic component elements or the electronic component element and the energization medium from being bonded (attached).
By using the plating apparatus of the present invention, it is possible to reliably carry out the electronic component manufacturing method according to any one of claims 1 to 3 and efficiently manufacture the electronic component.

In addition, as a driving means constituting the plating apparatus of the present invention, for example, by combining an eccentric load or a spring with a vibration motor, the eccentric vibration energy is generated, and this eccentric vibration energy is transmitted to the above-described container, By driving the container eccentrically, the container itself does not rotate, and driving means that gives the container a motion such that the locus of movement of the container becomes substantially circular is exemplified.
Moreover, in the plating apparatus of this invention, there is no restriction | limiting in particular in the specific shape and structure of a container, and there is no special restriction | limiting in the arrangement | positioning aspect of the cathode (electrode) with which the container is equipped.

  In the plating apparatus according to claim 5, the container is substantially cylindrical with a bottom, and is supported by a container holding member at a substantially central portion of the bottom wall, and the driving force of the driving means is supplied to the container via the container holding member. The driving means has a substantially circular locus along the circumferential direction of the container when the container is viewed in plan with respect to the flow state of the electronic component element and the energizing medium in the container. The flow drawn is a horizontal rotation flow, and when the region defined by the container holding member, the side wall and the bottom wall of the container is viewed in a vertical cross section, the flow that draws a substantially circular trajectory along the substantially circumferential direction of the region is vertically rotated. When the flow is set, the frequency of the current supplied to the vibration motor can be changed periodically to change the generation ratio of the transverse flow and longitudinal rotation flow. Without incurring It is possible to efficiently stir the electronic component element and the current-carrying medium in the container, and prevent the electronic component element or the electronic component element and the current-carrying medium from being bonded to each other while preventing the occurrence of adhesion (sticking) between the electronic component elements and the film. A plating apparatus capable of forming a plating film having a uniform thickness can be realized.

  The features of the present invention will be described in more detail below with reference to examples of the present invention.

  In the following embodiment, when a multilayer ceramic capacitor as shown in FIGS. 2A and 2B is manufactured, a plurality of internal electrodes 3 are arranged to face each other with the ceramic layer 2 interposed therebetween. In addition, an external formed by applying, drying and firing a conductive paste containing Ag as a conductive component on both end sides of a ceramic element (electronic component element) 1 which is drawn to end faces on different sides alternately. An example in which the Ni plating film 5 formed on the surface of the electrode 4 is used as an electronic component element, and Sn plating is performed on the Ni plating film 5 to form the Sn plating film 6 will be described as an example.

<Configuration of plating equipment>
FIG. 1 is a diagram showing a configuration of a plating apparatus according to an embodiment (Example 1) of the present invention.
The plating apparatus accommodates at least one drive unit 13 that generates eccentric vibration energy, an electronic component element 10, an energization medium (metal ball medium) 19 that functions as an energization medium, and an agitation medium 20. The container 14 is made of a material that allows the plating solution to pass therethrough (in this embodiment, a part of the bottom 16 is a wire mesh), the lower end side holds the container 14, and the upper end side is connected to the driving means 13. A container holding member 15, a cathode (cathode electrode) 17 disposed on the bottom 16 of the container 14, an anode electrode 27, and a plating tank 18 for storing a plating solution are provided.

The container 14 has a circular shape with an open top surface. The container holding member 15 is substantially circular in cross-section in the direction orthogonal to the axial direction, and the lower end side is connected to the approximate center of the bottom portion 16 of the container 14 to hold the container 14 and vibrate from the driving means 13 to the container. It is comprised so that the function which transmits may be fulfilled.
The cathode electrode 17 has a substantially circular planar shape, and a plurality of cathode electrodes 17 are arranged in the circumferential direction. Further, a power supply line is connected to the cathode electrode 17 and is connected to an external power source.

In the plating apparatus of the first embodiment, the driving means 13 includes the vibration motor 11, the eccentric load 21 for applying an eccentric load to the vibration motor 11, the motor support frame member 22 that supports the vibration motor 11, and the vibration receiving plate. 23, and a spring 12 that supports the vibration receiving plate 23, etc., and the eccentric vibration energy generated by operating the vibration motor 11 is transmitted to the container 14 to decenter the container 14, whereby the container 14 itself Is not rotated, and is configured to give a motion such that the locus of movement of the container 14 becomes a substantially circular shape.
Further, the driving means 13 periodically changes the motion state of the container 14 by periodically changing the frequency of the current supplied to the vibration motor 11, so that the contents in the container 14 (electronic component element 10, energization) For example, the medium 19 for stirring and the medium 20 for stirring) can be periodically changed.

<Plating treatment and evaluation>
Using the plating apparatus configured as described above, an electronic component element (external electrodes 4 are formed at both ends of the ceramic element 1 as shown in FIG. 2 and Ni plating is applied to the surface of the external electrode 4 by the following method. The ceramic element 10 on which the film 5 was formed was plated, and the Sn plating film 6 was formed on the Ni plating film 5.

The conditions such as the volume of the container, the dimensions of the electronic component element and the amount charged into the container, the diameter of the energizing medium and the amount charged into the container, the diameter of the stirring medium and the amount charged into the container, and the stirring conditions are as follows: Street.
(1) Container volume: 400cm ³
(2) Electronic component element Dimensions: Length L = 0.6mm, Width W = 0.3mm, Height T = 0.3mm
Input amount: 300,000
(3) Current-carrying media (steel balls)
Diameter: 0.5mm
Input amount: 300,000
(4) Stirring media (silicone rubber coated iron balls)
Diameter: 6mm
Input amount: 50cc
(5) Stirring conditions Hereinafter, stirring conditions will be described. First, the flow state produced under each stirring condition will be described. 3 (a) and 3 (b) are diagrams schematically showing a flow state, (a) is a diagram showing a state of transverse rotational flow, and (b) is a state of longitudinal rotational flow. FIG. 3A and 3B, the same reference numerals as those in FIG. 1 denote the same parts.
As shown in FIG. 3 (a), when the container 14 is viewed in plan, the state of flowing so as to draw a substantially circular locus along the circumferential direction of the container 14 as indicated by an arrow A is referred to as lateral rotational flow. As shown in FIG. 3B, when the region 30 defined by the container holding member 15, the side wall 26 and the bottom wall (bottom wall) 16 of the container 14 is viewed in a vertical cross section, Assuming that the state of flowing in the region 30 so as to draw a substantially circular trajectory is longitudinal rotation flow, the frequency of the current supplied to the vibration motor 11 and the contents in the container 14 (electronic component element, energization medium, and agitation medium) ) Is in the following relationship.
(a) Frequency 30 Hz:
Flow state mainly consisting of transverse rotational flow
(b) Frequency 40 Hz:
Flow condition with the same level of transverse and longitudinal flow
(c) Frequency 45 Hz:
Flow condition with the same level of transverse and longitudinal flow
(d) Frequency 50 Hz:
Flow state mainly consisting of longitudinal rotation flow
(e) Frequency 60 Hz:
In the flow state in which the ratio of the vertical rotation flow is higher than that in the case of the frequency of 50 Hz, the flow of the main rotation flow is a flow state. In the first embodiment, the frequency of the current supplied to the vibration motor is as follows. In this manner, Sn plating was performed for 150 minutes for all steps.
Test 1: 30 Hz constant (conventional example)
Test 2: 40 Hz → 45 Hz → 40 Hz → 45 Hz →
Test 3: 30Hz → 40Hz → 30Hz → 40Hz →…
Test 4: 30Hz → 50Hz → 30Hz → 50Hz →…
Test 5: 30 Hz → 40 Hz → 50 Hz → 30 Hz →.
Test 6: 30 Hz → 40 Hz → 50 Hz → 40 Hz → 30 Hz ...

While measuring the film thickness (n = 20) of the Sn plating film formed by performing Sn plating on said conditions, the CV value was computed by the following formula from the average value of the film thickness of Sn plating film.
CV value (%) = (standard deviation of Sn plating film thickness / average value of Sn plating film thickness) × 100
Furthermore, from the amount (X) of electronic component elements in which adhesion (sticking) has occurred and the total amount (Y) of electronic component elements subjected to plating, the rate of occurrence of bonding (sticking) is obtained by the following formula. (N = 300,000).
Rate of occurrence of sticking (sticking) (%) = X / Y × 100

  Table 1 shows the thickness of the Sn plating film, the CV value, and the occurrence rate of adhesion (sticking) obtained as described above.

As in the case of Test 1 in Table 1, when the frequency of the current supplied to the vibration motor is constant at 30 Hz, the occurrence rate of electronic component element adhesion (sticking) is as high as 2.5%, and the film thickness varies. Is also 12.2% (CV value), but as shown in Tests 2 to 6, the frequency of the current supplied to the vibration motor is changed to change the contents in the container (electronic component element). It has been confirmed that when the flow state of the energizing medium and the agitating medium is periodically changed, the rate of occurrence of adhesion (sticking) of electronic component elements decreases and the variation in film thickness also decreases. .
This is because, by changing the frequency of the current supplied to the vibration motor and changing the flow state of the contents in the container, (a) the dispersibility of the electronic component elements in a large number of energizing media is improved. This is because the probability that the electronic component elements flow side by side (runs parallel) decreases, and (b) the probability of contact between the electronic component element and the energizing media existing in the vicinity increases. Conceivable.

  In addition, when the frequency of the current supplied to the vibration motor is 60 Hz, the contact between the electronic component element and the energizing medium cannot be sufficiently obtained, and a plating film having a target film thickness cannot be obtained in a predetermined time. Although not evaluated in Example 1, it may be desirable to set the frequency to 60 Hz or more depending on the dimensions of the electronic component element, the shape of the container, and other conditions.

  In addition, according to the plating method of the first embodiment, variation in the thickness of the plating film is reduced, so that variation in quality within and between lots is reduced, and it is possible to supply electronic components with stable quality. At the same time, the rate of occurrence of electronic component element adhesion (sticking) decreases, so that the yield can be improved.

The electronic component element was plated under the following conditions. The conditions not described below were the same as those in Example 1 above.
(1) Container volume: 1300cm ³
(2) Electronic component element Dimensions: Length L = 1.0mm, Width W = 0.5mm, Height T = 0.5mm
Input amount: 100,000 pieces
(3) Current-carrying media (steel balls)
Diameter: 0.7mm
Input amount: 100,000 pieces
(4) Stirring media (silicone rubber coated iron balls)
Diameter: 10mm
Input amount: 50cc
(5) Stirring conditions The flow state was changed by periodically changing the frequency of the current supplied to the vibration motor as follows.
The frequency in Example 2 (the dimension of the electronic component element is length L = 1.0 mm, width W = 0.5 mm, height T = 0.5 mm) and the contents contained in the container (electronic component element, energization) The relationship between the flow state of the working medium and the stirring medium) is as follows.
(a) Frequency 30 Hz:
A flow state mainly composed of a transverse rotation flow, and a flow state in which the degree of the transverse rotation flow is larger than that at a frequency of 40 Hz
(b) Frequency 40 Hz:
Flow state mainly consisting of transverse rotational flow
(c) Frequency 50 Hz:
Flow condition with the same level of transverse and longitudinal flow
(d) Frequency 55 Hz:
Flow condition with the same level of transverse and longitudinal flow
(e) Frequency 60 Hz:
In this Example 2, the current supplied to the vibration motor is changed every 10 seconds so that the frequency of the current supplied to the vibration motor is as follows. went.
Test 11: 40 Hz constant (conventional example)
Test 12: 50 Hz → 55 Hz → 50 Hz → 55 Hz →
Test 13: 40 Hz → 50 Hz → 40 Hz → 50 Hz →
Test 14: 40 Hz → 60 Hz → 40 Hz → 60 Hz →
Test 15: 40 Hz → 50 Hz → 60 Hz → 40 Hz →
Test 16: 40 Hz → 50 Hz → 60 Hz → 50 Hz → 40 Hz ...

While measuring the film thickness (n = 20) of the Sn plating film formed by plating on said conditions, the CV value was computed from the average value of the film thickness of Sn plating film.
Table 2 shows the thickness of the Sn plating film, the CV value, and the occurrence rate of adhesion (sticking) obtained as described above.

As in the case of Test 11 in Table 2, when the frequency of the current supplied to the vibration motor is constant at 40 Hz, the occurrence rate of electronic component element bonding (sticking) is as high as 2.1%, and the film thickness varies. 11.2% (CV value) is also large, but as in the case of tests 12 to 16, the frequency of the current supplied to the vibration motor is changed to change the contents in the container (electronic component element) It has been confirmed that when the flow state of the energizing medium and the agitating medium is periodically changed, the rate of occurrence of adhesion (sticking) of electronic component elements decreases and the variation in film thickness also decreases. .
The reason why such an effect is obtained is the same as in the case of the first embodiment.

  Moreover, in Example 2, although evaluation at 30 Hz is not performed, it is considered that the degree of lateral rotation flow increases to 40 Hz or more, and therefore it is presumed that the film thickness variation of the Sn plating film increases. .

Condition of test 4 of Example 1 above, that is,
Test 4: 30Hz → 50Hz → 30Hz → 50Hz →…
Under these conditions, only the time for holding at each frequency was changed as follows, and Sn plating was performed. Other conditions are the same as those in the first embodiment.
Test 21: 30 Hz: 10 seconds, 50 Hz: 10 seconds (same as Test 4 in Example 1)
Test 22: 30 Hz: 20 seconds, 50 Hz: 20 seconds Test 23: 30 Hz: 30 seconds, 50 Hz: 30 seconds Test 24: 30 Hz: 10 seconds, 50 Hz: 20 seconds Test 25: 30 Hz: 20 seconds, 50 Hz: 10 seconds

While measuring the film thickness (n = 20) of the Sn plating film formed by plating on said conditions, the CV value was computed from the average value of the film thickness of Sn plating film.
Table 3 shows the Sn plating film thickness, CV value, and rate of adhesion (sticking) determined as described above.

  As shown in Table 3, when the holding time at each frequency is made longer than Test 21 (Test 4 of Example 1), the occurrence rate of electronic component element bonding (sticking) increases and the film thickness of the Sn plating film The variation of is also increasing. From this result, it can be seen that by shortening the time held at each frequency, the residence time of the contents in the container can be shortened and a good stirring state can be maintained.

In addition, from the results of Examples 1 to 3 above and the results of other studies, in the plating step in the method for manufacturing an electronic component element of the present invention,
(1) The electronic component elements or the bonding (sticking) between the electronic component elements and the current-carrying media is large in the area where there are few electronic component elements on the inner periphery of the container (usually the area below the stirring medium). There is a tendency to occur (the area on the inner peripheral side of the container has a lot of stirring media, and since the amount of electronic component elements is small, the current density becomes high and adhesion is likely to occur)
(2) In the case where the addition amount of the stirring medium is constant, when the frequency is increased, the electronic component element rotates in the container, and the electronic component element comes into contact with the stirring medium existing on the inner peripheral side of the container. , The adhesion of electronic component elements is reduced,
(3) Increasing the amount of agitation media will improve the efficiency of agitation and reduce the adhesion between electronic component elements.
(4) When the frequency of the electric current supplied to the vibration motor is less than 30 Hz, the electronic component element flows in a transverse direction, making it difficult to come into contact with the agitating medium, and there is a tendency that the adhesion (sticking) between the electronic component elements increases. is there,
(5) Increasing the frequency of the current supplied to the vibration motor increases the rate of longitudinal rotational flow, and if the frequency is increased to a certain level, the rotational direction when viewed in a plane (clockwise and counterclockwise) Rotation) may change (for example, when the frequency is 60 Hz, the rotation direction may change from clockwise rotation to counterclockwise rotation)
It is considered that the present invention can be further effectively realized by setting conditions in consideration of such knowledge.

In the method of manufacturing an electronic component according to the present invention, in the plating step, the electronic component element and the energization medium are accommodated in a container equipped with a cathode, immersed in a plating solution, and driven by the driving force of a driving means using a vibration motor. The container itself does not rotate, and the movement of the container moves in a substantially circular shape, and the frequency of the current supplied to the vibration motor is periodically changed to periodically change the electronic component element in the container. In addition, the electronic component element and the energizing medium are efficiently stirred in the container since the electronic component element is plated by energizing the cathode in the container while periodically changing the flow state of the energizing medium. In such a state where sufficient agitation is being performed, by conducting the plating by energizing the cathode, the electronic component elements or the electronic component elements And while preventing the occurrence of coalescence of the energizing medium (sticking), the film thickness on the electronic component element is able to form a uniform plated film.
Therefore, for example, a step of plating an electronic component having an external electrode formed on the surface of a ceramic element (electronic component element), such as a chip-type multilayer ceramic capacitor, and forming a plating film on the surface of the external electrode Thus, the present invention can be widely applied to a method for manufacturing an electronic component manufactured through the above process.

It is a figure which shows schematic structure of the plating apparatus concerning one Example of this invention. It is a figure which shows the multilayer ceramic capacitor which is a to-be-plated component, Comprising: (a) is sectional drawing, (b) is a perspective view. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the flow state in the container in the plating apparatus concerning one Example of this invention, (a) is a figure which shows the state which is flowing horizontally, (b) is the state which is flowing vertically. FIG. (a) is a figure which shows the conventional plating apparatus, (b) is the figure which expands and shows the principal part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ceramic element 2 Ceramic layer 3 Internal electrode 4 External electrode 5 Ni plating film 6 Sn plating film 10 Electronic component element 11 Vibration motor 12 Spring 13 Driving means 14 Container 15 Container holding member 16 Bottom part (bottom wall) of container
17 Cathode (cathode electrode)
18 Plating tank 19 Current-carrying media (metal ball media)
DESCRIPTION OF SYMBOLS 20 Stirring medium 21 Eccentric load 22 Motor support frame member 23 Vibration receiving plate 26 Side wall 27 Electrode for anode 30 Area | region A Arrow which shows lateral rotation flow B Arrow which shows vertical rotation flow

Claims (5)

  The electronic component element and the energizing medium are housed in a container equipped with a cathode, immersed in a plating solution, and the container itself is not rotated by the driving force of the driving means using a vibration motor, and the locus of movement of the container is substantially A circular motion is applied to the container, and the frequency of the current supplied to the vibration motor is periodically changed to periodically change the flow state of the electronic component element and the energizing medium in the container. On the other hand, a method for producing an electronic component, comprising the step of energizing the cathode in the container and plating the electronic component element. The container is substantially cylindrical with a bottom, and is supported by a container holding member at a substantially central portion of the bottom wall, and the driving force of the driving means is transmitted to the container via the container holding member. As well as
Regarding the flow state of the electronic component element and the energization medium in the container, a flow that draws a substantially circular trajectory along the circumferential direction of the container when the container is viewed in plane is a lateral rotation flow, the container holding member, When the region defined by the side wall and the bottom wall of the container is viewed in a vertical cross section, the flow that draws a substantially circular trajectory along the substantially circumferential direction of the region is a vertical rotation flow, and is supplied to the vibration motor. The method of manufacturing an electronic component according to claim 1, wherein the generation ratio of the transverse rotational flow and the longitudinal rotational flow is changed by periodically changing a frequency of a current to be generated.   By periodically changing the frequency of the current supplied to the vibration motor, the flow of the electronic component element and the energizing medium in the container is divided into a flow state mainly including a lateral rotation flow and a vertical rotation flow. 3. The method of manufacturing an electronic component according to claim 2, wherein the flow state is switched alternately. A container for storing an electronic component element and a current-carrying medium;
It is a driving means using a plating tank for storing the plating solution in which the container is immersed and a vibration motor, and the container itself does not rotate, and the movement of the container moves in a substantially circular shape. Driving means configured to periodically change the flow state of the electronic component element and the energization medium in the container by periodically changing the frequency of the current supplied to the vibration motor while being supplied to the container And a plating apparatus. The container is substantially cylindrical with a bottom, and is supported by a container holding member at a substantially central portion of the bottom wall, and the driving force of the driving means is transmitted to the container via the container holding member. As well as
The drive means periodically changes the frequency of the current supplied to the vibration motor, so that when the container is viewed in plan with respect to the flow state of the electronic component element and the energizing medium in the container, A flow that draws a substantially circular trajectory along the circumferential direction is a lateral rotational flow, and when the region defined by the container holding member, the side wall and the bottom wall of the container is viewed in a vertical cross section, the flow is substantially in the circumferential direction of the region. 5. The configuration is such that when the flow that draws a substantially circular locus along the vertical rotation flow is a vertical rotation flow, the generation ratio of the horizontal rotation flow and the vertical rotation flow can be changed. Plating equipment.

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