JP2011174157A - Plating device, plating method, and method for producing chip type electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plating device which can efficiently perform plating treatment in a short plating time, and can improve the quality of the object to be plated, a plating method, and a method for producing a chip type electronic component. <P>SOLUTION: The plating device includes: a first cathode electrode 23b composing at least a part of the inner circumferential wall face 23a of a recessed vessel 20a storing a plating liquid; a second cathode electrode 22b insulated from the first cathode electrode 23b and composing at least a part of the bottom face 22a of the recessed vessel 20a; an anode electrode 40 dipped into the plating liquid 30 stored into the recessed vessel 20a; and a rotating tool 21a rotating the recessed vessel 20a around a central axis 20T almost vertical to the bottom face 22a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a plating apparatus, a plating method, and a chip-type electronic component manufacturing method.

  In order to form a uniform plating layer on a small component, after putting the object to be plated (component) into the plating equipment, the rotating contact ring is rotated and the component is in contact with the rotating contact ring by centrifugal force. A technique is known in which plating is performed by energizing a rotating contact ring (see Patent Document 1).

  In this method, the parts are plated by repeating the rotation of the rotating contact ring and stopping or decelerating. In order to sufficiently plate parts, in the plating method described in Patent Document 1, it is necessary to repeat rotation of the rotating contact ring and stop or deceleration.

  However, if the plating time is too long, the parts may be lost due to an impact received during the rotation of the rotating contact ring. Further, by performing plating for a long time, the probability that dust adheres to the part increases, and the quality of the part may be deteriorated.

Japanese Patent No. 3126867

  The present invention has been made in view of such a situation, and an object thereof is a plating apparatus, a plating method, and a plating apparatus capable of efficiently performing a plating process with a short plating time and improving the quality of an object to be plated. It is to provide a method for manufacturing a chip-type electronic component.

In order to achieve the above object, a plating apparatus according to the present invention comprises:
A first cathode electrode constituting at least a part of the inner peripheral wall surface of the concave container storing the plating solution;
A second cathode electrode insulated from the first cathode electrode and constituting at least a part of a bottom surface of the concave container;
An anode electrode immersed in the plating solution stored in the concave container;
Rotating means for rotating the concave container around a central axis substantially perpendicular to the bottom surface.

The plating method according to the present invention includes a step of accommodating a plurality of objects to be plated in a concave container,
In a state where the plating solution is put inside the concave container, the concave container is rotated at a first rotation speed, and the plating object is moved near the inner wall surface at the bottom surface of the concave container; and
A wall surface moving step of rotating the concave container at a second rotation speed higher than the first rotation speed and moving the plating object upward along the inner wall surface;
The concave container is rotated at the second rotational speed, and the first cathode electrode formed on at least a part of the inner wall surface is energized, and is in direct or indirect contact with the first cathode electrode. A first plating step of plating the surface of the plating object;
A bottom return step of stopping rotation of the concave container and spreading the plating object to the bottom;
In a state where the object to be plated is in direct or indirect contact with the second cathode electrode formed on at least a part of the bottom surface, the surface of the object to be plated is plated by energizing the second cathode electrode. And a second plating step.

A method for manufacturing a chip-type electronic component according to the present invention includes a step of manufacturing an element body,
Forming a base electrode layer on the element body;
A method of manufacturing a chip-type electronic component having a step of forming a plating film on the surface of the base electrode layer,
Forming the plating film comprises:
Accommodating a plurality of element bodies formed with the base electrode layer in a concave container;
In a state where the plating solution is put inside the concave container, the concave container is rotated at a first rotation speed, and the element main body is moved near the inner wall surface at the bottom surface of the concave container; and
A wall surface moving step of rotating the concave container at a second rotation speed higher than the first rotation speed, and moving the element body upward along the inner wall surface;
The concave container is rotated at the second rotational speed, and the first cathode electrode formed on at least a part of the inner wall surface is energized, and is in direct or indirect contact with the first cathode electrode. A first plating step of plating the surface of the base electrode layer;
A bottom return step of stopping rotation of the concave container and spreading the element body to the bottom;
In a state where the base electrode layer of the element body is in direct or indirect contact with the second cathode electrode formed on at least a part of the bottom surface, the second cathode electrode is energized to pass through the base electrode layer. And a second plating step of plating the surface.

  In the plating apparatus, the plating method, and the chip type electronic component manufacturing method according to the present invention, the object to be plated (for example, the chip type electronic component, the same applies hereinafter) is directly or directly controlled by centrifugal force by controlling the rotation of the concave container. Indirect contact with the first cathode electrode. The phrase “the plating object indirectly contacts the first cathode electrode” means that, for example, the plating object is indirectly electrically connected to the first cathode electrode via another plating object or a conductive medium.

  In the present invention, control is performed so that the first cathode electrode is energized at the timing when the plating object directly or indirectly contacts the first cathode electrode, and the eluted material eluted from the anode electrode is removed from the plating object. It can be deposited on the surface. Further, by controlling the rotation of the concave container, the plating object directly or indirectly contacts the second cathode electrode by its own weight.

  In the present invention, control is performed so that the second cathode electrode is energized at the timing when the plating object directly or indirectly contacts the second cathode electrode, and the eluted material eluted from the anode electrode is removed from the plating object. It can be deposited on the surface.

  Thus, while controlling the rotation of the concave container, a voltage is applied to the second cathode electrode as well as the first cathode electrode at an effective timing. In this way, it is possible to ensure a relatively long plating time on the surface of the plating object in one plating cycle.

  In the present invention, control is performed so that the above-described cycle is repeated. Therefore, when the plating process is viewed in total, the plating time can be shortened and the plating process can be performed efficiently. Since the total processing time can be shortened, the probability that the plating target is missing or dust is attached is reduced, and the quality of the plating target after plating can be improved. In particular, in electronic parts such as chip varistors, it is necessary to avoid the surface of the element body from being exposed to the plating solution for a long period of time and adversely affecting the characteristics. Can be improved.

  Preferably, the plating apparatus according to the present invention performs switching control between a timing at which the first cathode electrode is energized and a timing at which the second cathode electrode is energized in accordance with the rotation state of the concave container by the rotating means. And a control means. By controlling the switching, the surface of the plating object can be efficiently plated.

  Preferably, the plating voltage when energizing the first cathode electrode is higher than the plating voltage when energizing the second cathode electrode. When the object to be plated comes into contact with the first cathode electrode, the object to be plated is strongly pressed against the first cathode electrode by the centrifugal force caused by the rotation of the concave container. Plating efficiency is improved by setting the plating voltage high.

  Preferably, the inner peripheral wall surface is inclined at an inclination angle larger than 90 degrees and smaller than 180 degrees with respect to the bottom surface. By having such an inclination, with the rotation of the concave container, the plating object easily climbs up the inner peripheral wall surface and disperses along the inner peripheral wall surface. Therefore, when the first cathode electrode is energized, the surface of the plating object can be more effectively plated.

  Preferably, also in the bottom surface moving step, the second cathode electrode is energized and the surface of the plating object is plated. By effectively combining the shape of the concave container and the rotation control / voltage application control, the surface of the object to be plated can be plated using the shape of the concave container to the maximum. As a result, the processing time when viewed in total can be further shortened, and the probability that the plating target is missing or dust is attached is reduced, and the quality of the plating target after plating can be improved. Become.

FIG. 1 is a cross-sectional view of a plating apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a chip-type electronic component processed by the plating method according to one embodiment of the present invention. FIG. 3 is an explanatory view showing a rotation control pattern of the concave container in the plating apparatus shown in FIG. 4 (A) to 4 (C) are cross-sectional views showing the steps of the plating method according to one embodiment of the present invention. FIG. 5 is an enlarged view of a main part showing details of the V part shown in FIG. FIG. 6 is an enlarged view of a main part showing details of the VI part shown in FIG.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
Multilayer chip varistors as plating objects

  First, the multilayer chip varistor 2 shown in FIG. 2 as a chip-type electronic component plated using the plating apparatus 20 shown in FIG. 1 according to an embodiment of the present invention will be described. As shown in FIG. 2, the multilayer chip varistor 2 includes an element body 10 having a configuration in which internal electrode layers 4 and 6 and a resistor layer 8 are stacked. A pair of external terminal electrodes 12 and 14 are formed on both end portions 11 and 13 of the element body 10 to be electrically connected to the internal electrode layers 4 and 6 disposed inside the element body 10.

  The internal electrode layers 4 and 6 are laminated such that each end face is exposed on the surface of the opposite end portions 11 and 13 of the element body 10. The pair of external terminal electrodes 12 and 14 are formed at both ends of the element body 10 and connected to the exposed end surfaces of the internal electrode layers 4 and 6 to constitute a varistor circuit.

  The resistor layer 8 is not particularly limited as long as it is a material having varistor characteristics. For example, the resistor layer 8 is composed of a zinc oxide varistor material layer. This zinc oxide-based varistor material layer has, for example, ZnO as a main component and rare earth elements, Co, IIIb group elements (B, Al, Ga and In), Si, Cr, alkali metal elements (K, Rb and Cs) as subcomponents. ) And alkaline earth metal elements (Mg, Ca, Sr and Ba) and the like. Alternatively, it may be made of a material containing ZnO as a main component and Bi, Co, Mn, Sb, Al, etc. as subcomponents.

  The resistor layer 8 may be composed of a capacitor material layer, an inductor material layer, an NTC thermistor material layer, etc. in addition to the zinc oxide varistor material layer.

  The internal electrode layers 4 and 6 are configured to include a conductive material. The conductive material contained in the internal electrode layers 4 and 6 is not particularly limited, but is preferably made of Pd or an Ag—Pd alloy. The thickness of the internal electrode layers 4 and 6 may be appropriately determined according to the use, but is usually about 0.5 to 5 μm.

  The external terminal electrodes 12 and 14 are also configured to include a conductive material. Although it does not specifically limit as a electrically conductive material contained in the external terminal electrodes 12 and 14, Usually, Ag, an Ag-Pd alloy, etc. are used. In the present embodiment, plated films 12c and 14c made of Ni and Sn films are formed by electroplating or the like on the surface of the base electrode layers 12p and 14p made of a paste electrode film such as Ag or an Ag—Pd alloy. It is. The thicknesses of the base electrode layers 12p and 14p may be appropriately determined according to the use, but are usually about 5 to 50 μm. Moreover, although the thickness of the plating films 12c and 14c may be appropriately determined according to the use, it is usually about 3 to 10 μm.

  The shape of the element body 10 is not particularly limited, but is usually a rectangular parallelepiped shape. Also, there is no particular limitation on the dimensions, and it is determined according to the application. In particular, it is 1005 shape (length 1.0 mm × width 0.5 mm × thickness 0.5 mm) or less, for example, small and light and the distance between electrodes is short. The effect of the method of the present embodiment is great when the size is 0603 (length 0.6 mm × width 0.3 mm × thickness 0.3 mm) or less.

  In the element body 10, outer resistor layers 18 are disposed at both outer ends of the internal electrode layers 4 and 6 and the resistor layer 8 in the stacking direction, and protect the inside of the element body 10. The material of the outer resistor layer 18 may be the same as or different from the material of the resistor layer 8, but is usually substantially the same as the material of the resistor layer 8, and is made of a semiconductor material.

  When the plating films 12c and 14c are formed outside the pair of base electrode layers 12p and 14p, the outer surface of the outer resistor layer 18 that is a semiconductor (the surface 10α of the element body 10) is formed during the plating process. A plating film is formed, and short-circuit defects are likely to occur. Therefore, a protective film 16 such as a glass coat is preferably formed on the surface 10α, but the protective film 16 is not necessarily formed. When the protective film 16 is formed, the thickness of the protective film 16 is preferably as thin as about 0.05 to 0.2 μm. If the protective film 16 is too thick, the contact between the internal electrode layers 4 and 6 and the base electrode layers 12p and 14p tends to be difficult when the base electrode layers 12p and 14p are formed after the protective film 16 is formed. is there.

The base electrode layers 12p and 14p are formed by an electrode paste baking process. The base electrode layers 12p and 14p are formed continuously with the end surface portions 12γ and 14γ located on the end surface of the element body 10 and the end surface portions 12γ and 14γ, and extend to the four side surfaces in the vicinity of the end surface of the element body 10. , 14β.
Manufacturing method of multilayer chip varistor

Next, a method for manufacturing the multilayer chip varistor 2 shown in FIG. 2 will be described.
First, the element body 10 is manufactured. In order to manufacture the element body 10, the resistor layer 8 (varistor layer) and the internal electrode layers 4 and 6 are formed by a printing method or a sheet method so that the internal electrode layers 4 and 6 are alternately exposed at both ends. They are alternately stacked, and the outer resistor layers 18 are stacked at both ends in the stacking direction to form a stacked body.

  Next, this laminate is cut to obtain a green chip. Next, a binder removal process is performed as necessary, and the green chip is fired to obtain the element body 10. Next, if necessary, the element body 10 is polished (for example, general barrel polishing) to expose the end portions of the internal electrodes on both end surfaces of the element body. Thereafter, electrode paste for forming the external terminal electrodes 12 and 14 is applied and baked on both ends of the element body 10 to form the base electrode layers 12p and 14p.

  Next, the surfaces of the base electrode layers 12p and 14p are polished to expose the conductive particles on the surfaces of the base electrode layers 12p and 14p, and the plating films 12c and 14c are uniformly formed on the surfaces of the base electrode layers 12p and 14p. Make it easier to form. The polishing may be general barrel polishing, but may be polishing by a polishing apparatus having a structure similar to a plating apparatus described later. That is, a method in which the element body is pressed against the inner wall surface of the rotating concave container with a centrifugal force and polished may be used.

  After such polishing, plating films 12c and 14c are formed on the surfaces of the base electrode layers 12p and 14p shown in FIG. 2 by electroplating using the plating apparatus shown in FIG. In this way, the multilayer chip varistor 2 shown in FIG. 2 is manufactured.

The formation of the protective film 16 such as a glass coat shown in FIG. 2 is preferably performed before the plating treatment, and may be performed before the formation of the base electrode layers 12p and 14p. Since the protective film 16 is sufficiently thin, it is possible to ensure the connection with the internal electrode layers 4 and 6 when forming the base electrode layers 12p and 14p on the end face of the element body 10.
Plating equipment

Next, a plating apparatus for performing the plating process will be described.
As shown in FIG. 1, the plating apparatus 20 includes a turntable 21, a bottom plate 22, a side ring 23, a slit forming member 24, a cover 25, a take-out lid 26, a supply pipe 27, and a discharge receptacle 28. And a discharge pipe 29.

  A shaft portion 21a is formed on the lower surface of the rotating disk 21, and the shaft portion 21a receives a driving force from a belt and a belt drive motor (not shown), thereby rotating clockwise and counterclockwise around the rotating shaft 20T. It can be rotated in both directions. A bottom plate 22 is fixed to the turntable 21, and a side ring 23 is fixed on the bottom plate 22.

  A slit forming member 24 is arranged on the upper surface of the side ring 23. A fixing portion 25a of the cover 25 is fixed to the upper surface of the slit forming member 24, and an extraction lid 26 is fixed to the upper surface of the cover 25 so as to be opened and closed. Thereby, scattering of the plating solution 30 described later is prevented.

  In the present embodiment, the slit forming member 24, the side ring 23, the bottom plate 22, and the turntable 21 are detachably fixed to the cover 25, and can be rotated together with the turntable 21. The take-out lid 26 is detachably attached to the cover 25 and is configured to be rotatable together with the cover 25. It is preferable that the supply pipe 27 is not fixed to the take-out lid 26 and does not rotate together with the turntable 21. In the present embodiment, the part that rotates together with the turntable 21 may be at least the side ring 23, and the slit forming member 24, the cover 25, the take-out lid 26, and the supply pipe 27 may not necessarily rotate. .

  The side ring 23 is a member that constitutes the concave container 20a together with the bottom plate 22, and an inner wall surface 23a is formed along the inner periphery. The inner wall surface 23a is inclined at a predetermined angle θ with respect to the upper surface of the bottom plate 22, that is, the bottom surface 22a of the concave container 20a. The predetermined angle θ is an inclination angle larger than 90 degrees and smaller than 180 degrees, more preferably 100 degrees to 120 degrees. The inner wall surface 23a is not necessarily a linear inclined surface, and may be a convex or concave curved inclined surface. However, the inner wall surface 23a is preferably a linear inclined surface.

  The height of the side ring 23 in the axial direction is not particularly limited, but is preferably 5 to 35 mm. Between the side ring 23 and the slit forming member 24, or between the slit forming member 24 and the fixing portion 25 a of the cover 25, a slit 24 a that connects the inside and the outside of the concave container 20 a is formed. The plating solution 30 is supplied from the supply pipe 27 to the inside of the concave container 20a, and the excess plating solution 30 is discharged to the outside of the container from the slit 24a, and is discharged to the outside through the discharge receiver 28 and the discharge pipe 29. Accordingly, after filtration, it is returned to the supply pipe 27.

  The anode electrode 40 is immersed in the plating solution 30 stored in the concave accommodating portion 20a. The anode electrode 40 may be rotatably held together with the concave container 20a. However, the anode electrode 40 is preferably not suspended from the concave container 20a but is suspended from above, and does not rotate together with the concave container 20a. It is like that. The anode electrode 40 holds a material that dissolves in the plating solution 30 and deposits as a plating film, such as Ni spheres.

  In the present embodiment, in the side ring 23, at least the inner wall surface 23a is made of a conductive material such as a conductive metal, and the inner wall surface 23a made of the conductive material forms the first cathode electrode 23b. Yes. The first cathode electrode 23b is connected to the control means 50, and the first plating voltage controlled by the control means 50 is applied to the first cathode electrode 23b.

  In the bottom plate 22, the bottom surface 22a of the concave container 20a is made of at least a conductive material such as a conductive metal and constitutes the second cathode electrode 22b. The second cathode electrode 22b is connected to the control means 50, and the second plating voltage controlled by the control means 50 is applied to the second cathode electrode 22b. The second plating voltage is lower than the first plating voltage, and the difference is preferably 1 to 3V.

  The first cathode electrode 23b and the second cathode electrode 22b are insulated. In the present embodiment, in the bottom plate 22, the first cathode electrode 23 b and the second cathode electrode 22 b are insulated by configuring the connection portion with the side ring 23 with an insulating member. You may do it.

The control means 50 is connected to a rotation means such as a motor for rotating the turntable 21, and controls the rotation of the concave container 20a by controlling the motor. The control means 50 switches and controls the timing of energizing the first cathode electrode 23b and the timing of energizing the second cathode electrode 22b in accordance with the rotational state of the concave container 20a. In the present embodiment, the control means 50 is constituted by a computer or the like, and includes plating voltage application means for the first cathode electrode 23b, the second cathode electrode 22b, and the anode electrode 40, and the rotation driving means for the turntable 21. It also serves as a control means.
Plating method

  In this embodiment, rotation control of the turntable 21 of the plating apparatus 20 shown in FIG. 1 is performed as shown in FIG. First, as shown in FIG. 4A, a large number of element bodies 10 on which the base electrode layers 12p and 14p shown in FIG. 2 are formed are put into the concave container 20a. The number of element bodies 10 to be input is not particularly limited, and for example, 1000 to 2000000 elements are input. These element bodies 10 are gathered at the center of the bottom surface 22a inside the concave container 20a in which the plating solution 30 is stored to form an element body group 10a.

  When the rotational speed is gradually increased while slowly rotating the concave container 20a in a certain direction (first step T01 / first variable speed region shown in FIG. 3), the element main body group 10a becomes the bottom surface of the concave container 20a. It moves slowly along the outer peripheral direction along 22a. Thereafter, in the second step T02 shown in FIG. 3, the concave container 20a rotates at a constant rotational speed (first constant speed region), and the element body group 10a is formed into a concave container as shown in FIG. In the bottom face 22a of 20a, it moves near the inner wall surface 23 (bottom face moving step).

  In the present embodiment, in the first step T01 and / or the second step T02, the first cathode voltage is not applied to the first cathode electrode 23b using the control means 50 shown in FIG. A second plating voltage is applied between the electrode 22b and the anode electrode 40. On the surface of the second cathode electrode 22b, as shown in FIG. 5, the element body 10 on which the base electrode layers 12p and 14p are formed is arranged in alignment. Actually, they are not necessarily neatly arranged and are arranged in a messy manner by folding, but there are some parts that are arranged in a microscopic manner, so here, as shown in FIG. It will be described as being arranged.

  As shown in FIG. 5, the base electrode layers 12p and 14p of the element body 10 are brought into contact with the second cathode electrode 22b to be energized, and metal components in the plating solution are deposited on the surfaces of the base electrode layers 12p and 14p. Processing is done. In FIG. 5, the base electrode layers 12p and 14p of the element body 10 are in direct contact with the second cathode electrode 22b to be energized, but actually the base electrode layers 12p and 14p are formed thereon. Many element bodies 10 are folded. The underlying electrode layers 12p and 14p of the other element body 10 that are folded are indirectly in contact with the second cathode electrode 22b via the underlying electrode layers 12p and 14p of the other element body 10 that are in contact therewith. Is energized to perform plating.

  In addition to the element body 10 as an object to be plated, although not shown, a conductive medium may be placed in the plating solution together with the element body 10. In that case, the underlying electrode layers 12p and 14p of the other element body 10 that are folded are electrically connected to the second cathode electrode 22b through the conductive medium and are subjected to plating.

  Next, in the third step T03 shown in FIG. 3, the concave container 20a is rotated at a higher rotational speed than in the first step T01 and the second step T02. During the third step T03, the rotational speed increases rapidly (second variable speed region). At this time, as shown in FIG. 4C, the element body group 10a moves upward along the inner wall surface 23a by a centrifugal force (wall surface moving step). Thereafter, as shown in FIG. 3, in the fourth step T04, the rotation speed (second constant speed region) with the highest plating efficiency is maintained.

  In the third step T03, energization to the first cathode electrode 23b and the second cathode electrode 22b is stopped. In the fourth step T04, the control means 50 shown in FIG. 1 applies a first plating voltage between the first cathode electrode 23 and the anode electrode 40. The second cathode electrode 22b is not energized.

  In the present embodiment, when the element body group 10a climbs up the inner wall surface 23a, the element body 10 is scattered in layers along the inner wall surface 23a by centrifugal force as shown in FIGS. 3 (C) and 6. Pressed. In that state, due to the centrifugal force, the probability that the element body 10 is placed horizontally is higher than the probability that the element body 10 is placed vertically with respect to the inner wall surface 23a, and the base electrode layers 12p and 14p are surely strong against the first cathode electrode 23b. The plating process is performed upon contact.

  In this plating process, the probability that the element bodies 10 collide with each other is also relatively reduced. Therefore, there is little possibility that the medium or another element body 10 or the inner wall surface 23a collides with the surface 10α (see the drawing) of the element body 10 present at a position recessed from the base electrode layers 12p and 14p. There is little damage to the surface 10α.

  In FIG. 6, the element main bodies 10 are arranged in a line. However, the element bodies 10 are not necessarily arranged in a line, and may be folded in several lines. In any case, since the centrifugal force acts, the probability that the element body 10 is placed horizontally is higher than the probability that the element body 10 is placed vertically with respect to the inner wall surface 23a. Therefore, the base electrode layers 12p and 14p of the other element body 10 that are folded are indirectly connected to the second cathode electrode 22b via the base electrode layers 12p and 14p of the other element body 10 that are in contact therewith. It contacts and is energized, and a plating process is performed reliably.

  When conductive media is contained in the plating solution other than the element body 10 as the plating object, the base electrode layers 12p and 14p of the element body 10 are connected to the second cathode via the conductive medium. The electrode 22b is indirectly contacted and energized to perform plating.

  Thereafter, in the fifth step T05 shown in FIG. 4, the rotational speed of the concave container 20a is rapidly reduced. In the fifth step T05, no plating voltage is applied to either the first cathode electrode 23b or the second cathode electrode 22b. Next, in the sixth step T06, a state in which the rotational speed of the concave container 20a is made zero is maintained. Even if the rotation of the concave container 20a is stopped, the liquid present in the concave container 20a continues to rotate due to the inertial force. Therefore, the element body 10 that has been pressed along the inner wall surface 23a is separated from the inner wall surface 23a by the rotational flow of the liquid, and is slowly stirred to the approximate center of the bottom surface 22a of the inner container 23a while swirling. While falling (bottom return process). The state is shown in FIG.

  In the sixth step T06, a second plating voltage may be applied between the second cathode electrode 22b and the anode electrode 40 as in the first step T01 and / or the second step T02.

  After that, as shown in FIG. 3, the first step T11 to the sixth step T16 are performed except that the rotation direction is different from the first step T01 to the sixth step T06, and then the first step T01 to the sixth step T16. Six steps T06 and the first step T11 to the sixth step T16 are alternately repeated. By repeating such a cycle, the surface of the base electrode layers 12p and 14p formed on each of the large number of element bodies 10 is uniformly plated, thereby suppressing the occurrence rate of defective products that cause plating defects. it can. As a result, as shown in FIG. 2, the multilayer chip varistor 2 in which the plating films 12c and 14c are formed is obtained.

  In the plating apparatus, the plating method, and the chip-type electronic component manufacturing method using the same according to the present embodiment, by controlling the rotation of the concave container, the ground electrode layer of the element body 10 as a plating object is obtained by centrifugal force. 12p and 14p contact the 1st cathode electrode 23b directly or indirectly.

  In the present embodiment, the first cathode electrode 23b is energized at a timing (steps T04 and T14 shown in FIG. 3) where the base electrode layers 12p and 14p of the element body 10 directly or indirectly contact the first cathode electrode 23b. Control is performed as follows. Therefore, the eluate eluted from the anode electrode 40 can be deposited on the surface of the base electrode layers 12p and 14p and plated.

  Further, as in steps T01 (T11), T02 (T12), and T06 (T16) shown in FIG. 3, the element body 10 is directly or indirectly controlled by the second cathode electrode by controlling the rotation of the concave container 20a. A state of contacting 22b can be created. In this state, the control means 50 can energize the second cathode electrode 22b to deposit the eluate eluted from the anode electrode on the surface of the object to be plated for plating.

  Thus, in this embodiment, while controlling rotation of the concave container 20a, a voltage is applied with effective timing not only to the first cathode electrode 23a but also to the second cathode electrode 22a. In this way, it is possible to ensure a relatively long plating time in a single plating cycle.

  Moreover, in the present embodiment, control is performed so that the above-described cycle is repeated. Therefore, when the plating process is viewed in total, the plating time can be shortened and the plating process can be performed efficiently. Since the total processing time is shortened, the probability that the element main body 10 is missing or dust is attached is reduced, and the quality of parts after plating can be improved. In particular, in an electronic component such as the chip varistor 2, it is necessary to avoid that the surface of the element body 10 is exposed to the plating solution for a long time and adversely affect the characteristics. By shortening the plating process time, the reliability of the varistor 2 can be reduced. Can be improved.

  In the present embodiment, when the element body 10 is in contact with the first cathode electrode 23b, the element body 10 is strongly pressed against the first cathode electrode 23b by the centrifugal force due to the rotation of the concave container 20a. Even if the plating voltage is high, sparks are hardly generated, and the plating efficiency is improved by setting the plating voltage high.

  In addition, in the present embodiment, the inner peripheral wall surface 23a of the concave container 20a is inclined in a taper-shaped direction toward the upper side along the rotation axis 20T, so that the element body 10 is rotated along with the rotation of the concave container 20a. The inner peripheral wall surface 23a is easily climbed up and dispersed along the inner peripheral wall surface 23a. Therefore, when the first cathode electrode 23b formed on the inner peripheral wall surface 23a is energized, the surface of the base electrode layers 12p and 14p can be more effectively plated.

  Further, in the present embodiment, since plating can be performed without using media, the adhesion of chip parts and debris of the media generated by the impact of the media does not cause uneven plating or poor appearance. Further, since no media is used, it is not necessary to separate the media and the element body 10 after plating.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention. For example, in the above-described embodiment, the multilayer chip varistor has been described as an example. However, the present invention is not limited to this, and the chip type electronic component to which the plating apparatus and the plating method of the present invention are applied includes a multilayer capacitor and a chip varistor. A chip inductor, a chip NTC thermistor, or the like may be used. The plating object to which the plating apparatus and the plating method of the present invention are applied is not limited to a chip-type electronic component, and examples thereof include powder (5 to 100 μm), connectors, reed switches, nails, bolts, nuts, washers and the like. Such small items (small parts) are exemplified.

  In the above-described embodiment, the entire inner wall surface 23a of the side ring 23 is configured as the first cathode electrode 23b. However, the present invention is not limited thereto, and at least a part of the inner wall surface 23a is defined as the first cathode electrode 23b. It may be configured. In the above-described embodiment, the substantially entire bottom surface 22a of the concave container 20a is configured as the second cathode electrode 22b. However, in the present invention, at least a part thereof is configured as the second cathode electrode 22b. May be.

2 ... Laminated chip varistors 6, 8 ... Internal electrodes 10 ... Element main bodies 12, 14 ... External terminal electrodes 12p, 14p ... Base electrode layers 12c, 14c ... Plating films 12β, 14β ... Side portions 12γ, 14γ ... End face portions 16 ... Protection Membrane 20 ... Plating apparatus 20a ... Concave container 22 ... Bottom plate 22a ... Bottom surface 22b ... Second cathode electrode 23 ... Side ring 23a ... Inner wall surface 23b ... First cathode electrode 30 ... Plating solution 40 ... Anode electrode 50 ... Control means

Claims (10)

A first cathode electrode constituting at least a part of the inner peripheral wall surface of the concave container storing the plating solution;
A second cathode electrode insulated from the first cathode electrode and constituting at least a part of a bottom surface of the concave container;
An anode electrode immersed in the plating solution stored in the concave container;
And a rotating means for rotating the concave container about a central axis substantially perpendicular to the bottom surface.   The plating apparatus according to claim 1, wherein the inner peripheral wall surface is inclined at an inclination angle greater than 90 degrees and smaller than 180 degrees with respect to the bottom surface.   The control unit according to claim 1 or 2, further comprising: a switching unit that controls switching between a timing of energizing the first cathode electrode and a timing of energizing the second cathode electrode in accordance with a rotation state of the concave container by the rotating unit. The plating apparatus as described in.   The plating apparatus according to claim 3, wherein the control unit sets a plating voltage applied to the first cathode electrode higher than a plating voltage applied to the second cathode electrode. Storing a plurality of objects to be plated in a concave container;
In a state where the plating solution is put inside the concave container, the concave container is rotated at a first rotation speed, and the plating object is moved near the inner wall surface at the bottom surface of the concave container; and
A wall surface moving step of rotating the concave container at a second rotation speed higher than the first rotation speed and moving the plating object upward along the inner wall surface;
The concave container is rotated at the second rotational speed, and the first cathode electrode formed on at least a part of the inner wall surface is energized, and is in direct or indirect contact with the first cathode electrode. A first plating step of plating the surface of the plating object;
A bottom return step of stopping rotation of the concave container and spreading the plating object to the bottom;
In a state where the base electrode layer of the object to be plated is in direct or indirect contact with the second cathode electrode formed on at least a part of the bottom surface, the second cathode electrode is energized to supply the object to be plated. And a second plating step of plating the surface of the plating.   The plating method according to claim 5, wherein the second cathode electrode is energized and the surface of the plating object is plated in the bottom surface moving step.   The plating method according to claim 5 or 6, wherein a plating voltage when the first cathode electrode is energized is larger than a plating voltage when the second cathode electrode is energized. Manufacturing the element body;
Forming a base electrode layer on the element body;
A method of manufacturing a chip-type electronic component having a step of forming a plating film on the surface of the base electrode layer,
Forming the plating film comprises:
Accommodating a plurality of element bodies formed with the base electrode layer in a concave container;
In a state where the plating solution is put inside the concave container, the concave container is rotated at a first rotation speed, and the element main body is moved near the inner wall surface at the bottom surface of the concave container; and
A wall surface moving step of rotating the concave container at a second rotation speed higher than the first rotation speed, and moving the element body upward along the inner wall surface;
The concave container is rotated at the second rotational speed, and the first cathode electrode formed on at least a part of the inner wall surface is energized, and is in direct or indirect contact with the first cathode electrode. A first plating step of plating the surface of the base electrode layer;
A bottom return step of stopping rotation of the concave container and spreading the element body to the bottom;
In a state where the base electrode layer of the element body is in direct or indirect contact with the second cathode electrode formed on at least a part of the bottom surface, the second cathode electrode is energized to pass through the base electrode layer. And a second plating step for plating the surface. A method for manufacturing a chip-type electronic component.   9. The method for manufacturing a chip-type electronic component according to claim 8, wherein the second cathode electrode is energized and the surface of the base electrode layer is plated during the bottom surface moving step.   The method for manufacturing a chip-type electronic component according to claim 8 or 9, wherein a plating voltage when the first cathode electrode is energized is larger than a plating voltage when the second cathode electrode is energized.

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