JP5471585B2 - Manufacturing method of chip-type electronic component - Google Patents

Description

  The present invention relates to a method for manufacturing a chip-type electronic component. More specifically, the present invention relates to a method of forming a plating film on the surface of a base electrode layer formed on an end face of an element body, and may damage the surface of the element body. The present invention relates to a method for manufacturing a chip-type electronic component with a small amount.

  In chip-type electronic components such as ceramic capacitors and varistors, it is necessary to form terminal electrodes on the outer surface of a ceramic element body. Therefore, first, a base electrode layer is formed by baking a paste film on the surface of the element body, and then a terminal electrode is formed by applying a plating film to the surface of the base electrode layer.

  Usually, the paste film contains a glass component in order to improve the adhesion between the element body and the base electrode. In particular, when the element body is made of semiconductor ceramic, in order to prevent the plating solution from penetrating from the base electrode to the internal electrodes and elements and affecting the characteristics, the glass component contained in the base electrode should be increased. There is. However, if the surface of the base electrode layer has a large amount of glass component, the conductive particles are likely to be embedded in the glass component on the surface of the base electrode layer, and the surface of the paste film is unlikely to have a plating film. Therefore, the surface of the paste film may be barrel-polished.

  For example, an electronic component having a base electrode composed of a paste film is put into a barrel device together with media and water, and the barrel device is rotated (barrel polishing). As a result, the glass component on the surface of the base electrode layer may be polished to expose the conductive particles on the surface of the base electrode layer, thereby facilitating plating on the surface of the paste film.

  In addition, in order to improve the smoothness of the external electrode, there is a technique (rotary pot polishing) in which an electronic component having an external electrode is put into a rotating pot together with cobblestone (media) and water made of zirconia and the rotating pot is rotated. It is known (see Patent Document 1).

  However, when barrel polishing is performed, because the media is used, the surface of the element is damaged by the impact of the medium, micro cracks are generated on the surface, or debris due to chipping of the element or the media is caused by the surface of the element body or the base electrode layer It adheres to the surface of the film and the plating film adheres unevenly, which contributes to poor appearance. Further, with the miniaturization of the element main body, the size of the medium is also miniaturized, and it is difficult to separate the element main body and the medium after the polishing process.

  In particular, in a small chip-type electronic component, since the distance between the terminal electrodes is short, there is a high demand for forming a protective film such as a glass coat on the surface of the element body located therebetween. By forming the protective film, a plating film is formed on the surface of the element body in the subsequent plating step, thereby preventing a short circuit failure or the like from occurring.

  However, in the conventional method, when a protective film such as a glass coat is formed before the polishing step, the protective film may be damaged by the impact of the media, and the protective film may be peeled off.

  Furthermore, in the conventional method, particularly when a small element body is polished, there are not a few element bodies that float on the liquid surface of the liquid used for polishing, which may result in incomplete polishing and poor plating. There is.

Japanese Patent Laid-Open No. 7-22268

  The present invention has been made in view of such a situation, and an object thereof is to eliminate the need to separate the element body and the medium, and to reliably provide a plating film on the surface of the base electrode layer formed on the end face of the element body. Another object of the present invention is to provide a method of manufacturing a chip-type electronic component that can be formed in a small amount and that is less likely to damage the surface of the element body.

In order to achieve the above object, a method for manufacturing a chip-type electronic component according to the present invention includes:
A method of manufacturing a chip-type electronic component having an element body in which an internal electrode is formed and a terminal electrode that covers an end surface of the element body from which the internal electrode is exposed,
Forming a base electrode layer to be a part of the terminal electrode on the end face of the element body;
Accommodating a plurality of element bodies each having the underlying electrode layer formed therein, in a concave container;
A bottom moving step of rotating the concave container at a first rotational speed and moving the element main body near the inner wall surface at the bottom of the concave container, with the liquid inside the concave container;
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;
And a bottom surface returning step for stopping the rotation of the concave container.

  In the method for manufacturing a chip-type electronic component according to the present invention, first, the concave container is slowly rotated inside the concave container, and the element body is moved near the inner wall surface on the bottom surface of the concave container. Thereafter, the concave container is rotated at a higher rotational speed, and the element body is moved upward along the inner wall surface by centrifugal force.

  At that time, the surface of the base electrode layer is polished by frictional heat caused by sliding when the element body climbs the inner wall surface, or by pressing force against the inner wall surface acting on the element body due to centrifugal force. By polishing the surface of the base electrode, a large number of conductive particles are exposed on the surface of the base electrode by polishing the glass component of the base surface or stretching the conductive particles to cover the glass component. As a result, it becomes easy to form a plating film uniformly on the surface of the base electrode layer.

  Moreover, in the method of the present invention, the surface of the base electrode layer can be polished by pressing the base electrode layer of the element body against the inner wall surface by using only the polishing liquid without using a medium. In addition, when the element body climbs the inner wall surface, the element body is scattered and pressed along the inner wall surface by centrifugal force, and the probability that the element bodies collide with each other during polishing is relatively high. Less. Therefore, the surface of the element main body present at a position recessed from the base electrode layer is less likely to collide with the medium, the element main body, or the inner wall surface, and damage to the surface of the element main body is small.

  After the element body is pressed along the inner wall surface, the rotation of the concave container is stopped. Even if the rotation of the concave container is stopped, the liquid existing inside the concave container continues to rotate due to the inertial force. For this reason, the element main body pressed along the inner wall surface is separated from the inner wall surface by the rotational flow of the liquid, and slowly falls while being swirled to the approximate center of the bottom surface of the inner container while swirling.

  Therefore, it is possible to repeatedly perform a basic cycle in which the bottom surface moving step, the wall surface moving step, and the bottom surface returning step are performed in this order. A certain base electrode layer is uniformly polished, and the occurrence rate of defective products that cause poor plating can be suppressed.

  Preferably, when n is an integer, the direction of rotation of the concave container in the nth basic cycle is opposite to the direction of rotation of the concave container in the (n + 1) th basic cycle. By rotating in the reverse direction in this way, the uniformity of polishing of the base electrode layer formed on each of a large number of element bodies is improved, and the occurrence rate of defective products that cause poor plating can be further suppressed.

  Preferably, the inner wall surface is inclined with respect to the bottom surface at an inclination angle greater than 90 degrees and smaller than 180 degrees, and more preferably at an inclination angle of 100 degrees to 120 degrees. By tilting the inner wall surface, when the element body climbs up the inner wall surface, the element body is scattered in layers along the inner wall surface and easily pressed by the centrifugal force.

  Preferably, the first rotation speed may have a first variable speed area where the rotation speed gradually increases, and then a first constant speed area where the rotation speed does not change. The second rotational speed may have a second variable speed region in which the rotational speed gradually increases, and may further have a second constant speed region in which the rotational speed does not change thereafter.

  In the second variable speed region at the second rotational speed, the element body mainly has an action of climbing up the element body along the inner wall surface and spreading the element body along the inner wall surface in layers. The second constant speed region at the second rotational speed mainly has an action of maintaining a state in which the base electrode layer of the element body is pressed while sliding on the inner wall surface.

FIG. 1 is a cross-sectional view of a chip-type electronic component manufactured by a method according to an embodiment of the present invention. FIG. 2 is a schematic sectional view of a polishing apparatus for realizing a method according to an embodiment of the present invention. FIGS. 3A to 3C are process diagrams showing a method according to an embodiment of the present invention. FIG. 4 is an explanatory view showing a rotational speed control pattern of the polishing apparatus showing the method according to one embodiment of the present invention. FIG. 5 is an enlarged view of a main part of the V part shown in FIG. 6A is a schematic cross-sectional view showing the distribution of conductive particles before polishing the terminal electrode, and FIG. 6B is a schematic cross-sectional view showing the distribution of conductive particles after polishing.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
First, the multilayer chip varistor 2 shown in FIG. 1 as a chip-type electronic component manufactured by the method according to an embodiment of the present invention will be described. The multilayer chip varistor 2 has an element body 10 having a configuration in which internal electrode layers 4 and 6 and a resistor layer 8 are laminated. 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. Furthermore, if necessary, plated films 12c and 14c made of Ni and Sn films are formed on the surface of the base electrode layers 12p and 14p made of a paste electrode film such as Ag or Ag-Pd alloy by electroplating or the like. 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, the size is 1005 (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 smaller than the short 0603 shape (length 0.6 mm × width 0.3 mm × thickness 0.3 mm), the effect of the method of this embodiment is great.

  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.

  Therefore, 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 which is a semiconductor (the surface 10α of the element body 10) is formed during the plating process. Is likely to cause a short circuit due to the formation of a plating film. Therefore, a protective film 16 such as a glass coat is preferably formed on the surface 10α. However, in the present invention, 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.

  In the present embodiment, the roughness of the surface 10α of the element body 10 that is not covered with the external terminal electrodes 12 and 14 is represented by α · Ra, and the roughness of the surface portions 12β and 14β of the external terminal electrodes 12 and 14 is defined as When expressed as β · Ra, α · Ra is preferably 0.02 to 0.4 μm, more preferably 0.05 to 0.3 μm, and β · Ra is preferably 0.05 to 0.3 μm. It is 7 μm, more preferably 0.1 to 0.5 μm. The ratio of α · Ra and β · Ra is 0.5 ≦ β · Ra / α · Ra ≦ 10, preferably 1 ≦ β · Ra / α · Ra ≦ 4. The roughness is an arithmetic average roughness.

  In the present embodiment, the value of the surface roughness β · Ra of the side surface portions 12β and 14β of the external terminal electrodes 12 and 14 is smaller than the value of the surface roughness γ · Ra of the end surface portions 12γ and 14γ. The surface roughness γ · Ra of the end face portions 12γ and 14γ is preferably 0.05 to 0.8 μm, more preferably 0.1 to 0.5 μm.

  The surface roughness α · Ra is the surface roughness on the surface 10α of the element body 10. When the protective film made of glass coat is formed by a thin film method such as sputtering, the surface roughness is the same as the surface roughness of the protective film 16. Become. The surface roughness β · Ra and γRa is the surface roughness of the base electrode layers 12p and 14p, but the surface of the plating films 12c and 14c has the same surface roughness due to the characteristics of the plating process.

Next, a method for manufacturing the multilayer chip varistor 2 shown in FIG. 1 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. It laminates | stacks alternately, the outer side resistive material layer 18 is laminated | stacked on the both ends of the lamination direction, and a laminated body is formed.

  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, an 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, after performing a polishing process to be described later, plated films 12c and 14c are formed on the surfaces of the base electrode layers 12p and 14p by electroplating. In this way, the multilayer chip varistor 2 shown in FIG. 1 is manufactured.

  The formation of the protective film 16 such as a glass coat is preferably performed before the plating process, 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.

  Next, the polishing process performed before the plating process will be described. Before that, a polishing apparatus used for the polishing process will be described first.

  As shown in FIG. 2, the polishing 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 polishing liquid 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 polishing liquid 30 is supplied from the supply pipe 27 to the inside of the concave container 20 a, and the excess polishing liquid 30 is discharged from the slit 24 a to the outside of the container, and is discharged to the outside through the discharge receiver 28 and the discharge pipe 29.

  In this embodiment, as the polishing liquid, water not containing media is used, but a solvent or the like may be used.

  In the present embodiment, the rotation of the turntable 21 of the polishing apparatus 20 shown in FIG. 2 is controlled as shown in FIG. First, as shown in FIG. 3A, a large number of element bodies 10 on which the base electrode layers 12p and 14p shown in FIG. 1 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 supplied with the polishing liquid 30 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. 4), the element body group 10a is moved to the bottom surface of the concave container 20a. It moves slowly along the outer peripheral direction along 22a. After that, in the second step T02 shown in FIG. 4, the concave container 20a rotates at a constant rotational speed (first constant speed region), and the element body group 10a has 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).

  Next, in the third step T03 shown in FIG. 4, 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. 3C, 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. 4, in the fourth step T04, the rotational speed (second constant speed region) with the highest polishing efficiency is maintained.

  In the third step T03 and the fourth step T04 shown in FIG. 4, the inner side acting on the element main body group 10a due to frictional heat generated when the element main body group 10a shown in FIG. The surface of the base electrode layers 12p and 14p shown in FIG. 5 is polished only by the polishing liquid 30 without using a medium by the pressing force against the wall surface 23a.

  By polishing the surfaces of the base electrode layers 12p and 14p, the glass component 12r existing on the surfaces of the base electrode layers 12p and 14p is polished as shown in FIGS. Many conductive particles 12q are exposed on the surfaces of the electrode layers 12p and 14p. As a result, the plating films 12c and 14c (see FIG. 1) are easily formed uniformly on the surfaces of the base electrode layers 12p and 14p. In FIGS. 6A and 6B, for the sake of clarity, the conductive particles 12q are less than the glass component 12r, but actually there are more conductive particles 12q.

  In the present embodiment, when the element body group 10a climbs up the inner wall surface 23a, the element body 10 is separated into layers along the inner wall surface 23a by centrifugal force as shown in FIGS. 3 (C) and 5. Pressed. Therefore, the probability that the element bodies 10 collide with each other during polishing is relatively reduced. Therefore, there is little possibility that a medium or another element body 10 or the inner wall surface 23a collides with the surface 10α (see FIG. 1) of the element body 10 present at a position recessed from the base electrode layers 12p and 14p. The damage to the surface 10α of 10 is small.

  Thereafter, in the fifth step T05 shown in FIG. 4, the rotational speed of the concave container 20a is rapidly reduced, and in the sixth step T06, the rotational speed of the concave container 20a is made zero. 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.

  Thereafter, as shown in FIG. 4, the same first step T11 to sixth step T16 are performed except that the rotation direction is different from that of the first step T01 to 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 base electrode layers 12p and 14p respectively formed on a large number of element bodies 10 are uniformly polished, and the occurrence rate of defective products that cause plating defects can be suppressed.

  In the method of the present embodiment, the surface of the base electrode layers 12p and 14p is pressed by sliding the base electrode layers 12p and 14p of the element body 10 against the inner wall surface 23a with only the polishing liquid 30 without using a medium. Can be polished. In the method of the present embodiment, since no media is used, the adhesion of chip parts and media debris generated by impact by 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 polishing.

  In the method of this embodiment, when the element body 10 climbs up the inner wall surface 23a, the element body 10 is scattered and pressed along the inner wall surface 23a by a centrifugal force. Therefore, the probability that the element bodies 10 collide with each other during polishing is relatively reduced. Therefore, there is little possibility that a medium or another element body 10 or the inner wall surface 23a collides with the surface 10α (see FIG. 1) of the element body 10 present at a position recessed from the base electrode layers 12p and 14p. The damage to the surface 10α of 10 is small. Since the damage to the surface 10α of the element body 10 is small, the thin protective film 16 made of a glass coat can be formed before the polishing step, preferably before the formation of the base electrode layers 12p and 14p. Even if the protective film 16 is formed, the protective film 16 is less likely to be damaged during the polishing process of the base electrode layers 12p and 14p, and the plating is performed up to the surface 10α of the element body 10 during the subsequent plating process. The formation can be effectively prevented.

  In the present embodiment, as shown in FIG. 5, when the element body 10 is polished by being pressed against the inner wall surface 23a by centrifugal force, the inner wall surface 23a has side surface portions of the base electrode layers 12p and 14p. There is a high probability that 12β and 14β (see FIG. 1) are mainly pressed. Therefore, when the method of the present embodiment is used, the surface of the side surface portion 12β shown in FIG. 1 is polished more than the end surface portion 12γ, and the value of the surface roughness β · Ra of the side surface portion 12β is the surface of the end surface portion 12γ. It tends to be smaller than the value of roughness γ · Ra.

  Therefore, in the method of the present embodiment, the end surface portion 12γ is not excessively shaved, and thus the surface roughness γ · Ra of the end surface portion 12γ is sufficiently large. Therefore, the corners of the element body 10 can be prevented from being exposed at the corners of the base electrode layers 12p and 14p, and the adhesion to the plating films 12c and 14c is good.

  Further, in the method of the present embodiment, the surface roughness shown in FIG. 1 is controlled by controlling the process time of steps T01 to T16 shown in FIG. 4, the rotational speed in each step, the acceleration of the rotational speed, the number of cycle repetitions, and the like. The multilayer chip varistor 2 having the above relationship can be easily manufactured. That is, the roughness of the surface 10α of the element body 10 not covered with the external terminal electrodes 12 and 14 is represented by α · Ra, and the roughness of the surface portions 12β and 14β of the external terminal electrodes 12 and 14 is represented by β · Ra. Α · Ra is preferably 0.02 to 0.4 μm, more preferably 0.05 to 0.3 μm, and β · Ra is preferably 0.05 to 0.7 μm. Preferably it can be 0.1-0.5 micrometer. The ratio of α · Ra and β · Ra can be 0.5 ≦ β · Ra / α · Ra ≦ 10, preferably 1 ≦ β · Ra / α · Ra ≦ 4.

  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 chip-type electronic components to which the method of the present invention is applied include multilayer capacitors, chip varistors, chip inductors, A chip NTC thermistor or the like may be used.

2 ... Multilayer chip varistor 6, 8 ... Internal electrode 10 ... Element body 12, 14 ... External terminal electrode 12p, 14p ... Base electrode layer 12c, 14c ... Plating film 12β, 14β ... Side portion 12γ, 14γ ... End face portion 16 ... Protection Film 20 ... Polishing apparatus 20a ... Concave container 22a ... Bottom 23a ... Inner wall surface 30 ... Polishing liquid

Claims (5)

A method of manufacturing a chip-type electronic component having an element body in which an internal electrode is formed and a terminal electrode that covers an end surface of the element body from which the internal electrode is exposed,
Forming a base electrode layer to be a part of the terminal electrode on the end face of the element body;
Accommodating a plurality of element bodies each having the underlying electrode layer formed therein, in a concave container;
A bottom surface moving step of rotating the concave container at a first rotational speed and moving the element main body near the inner wall surface at the bottom surface of the concave container with a liquid containing no medium inside the concave container; ,
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;
And a bottom surface returning step for stopping rotation of the concave container.     The manufacturing method of the chip-type electronic component according to claim 1, wherein a basic cycle in which the bottom surface moving step, the wall surface moving step, and the bottom surface returning step are performed in this order is repeated.     The rotation direction of the concave container in the nth basic cycle performed when n is an integer, and the rotational direction of the concave container in the (n + 1) th basic cycle are opposite directions. A method for manufacturing a chip-type electronic component.     The method for manufacturing a chip-type electronic component according to claim 1, wherein the inner wall surface is inclined with respect to the bottom surface at an inclination angle that is greater than 90 degrees and smaller than 180 degrees.     The first rotation speed has a first variable speed region in which the rotation speed gradually increases, and the second rotation speed has a second variable speed region in which the rotation speed gradually increases. A method for producing a chip-type electronic component as described in 1 above.

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