JP2006274353A - Barrel plating device and production method of electronic part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a barrel plating device capable of surely forming a plating film of a desired thickness to a portion to be formed with the plating film even when downsizing is progressed. <P>SOLUTION: The barrel plating device charges an electronic part element 31 as a material to be plated into a barrel 2 and applies plating thereto while rotating the barrel 2 within a plating solution 22 in state state of inclining the axial direction of the barrel 2 with respect to a horizontal direction. The barrel 2 has a pair of end surfaces 2b, 2c arranged at both ends in the axial direction and is extended from the inner side of the at least one end surface of a pair of the end surfaces 2b, 2c into the inside of the barrel 2 and is equipped with feeding terminals 6, 16 bent so as to extend in the direction along the inside surface of the end surfaces 2b, 2c. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to, for example, a barrel plating apparatus used for forming a plating film on an electronic component element body and a method of manufacturing an electronic component using the barrel plating apparatus. The present invention relates to a barrel plating apparatus having a structure capable of being formed and an electronic component manufacturing method using the barrel plating apparatus.

  Conventionally, for example, in forming an external electrode such as a multilayer ceramic electronic component, a method in which a base electrode is formed by baking a conductive paste and then a plating film is formed on the base electrode. In forming such a plating film, a barrel plating method is used to form a plating film on many ceramic electronic components at once.

  Patent Document 1 below discloses an example of a method for manufacturing an electronic component using the above barrel plating method. FIG. 8 is a perspective view showing a barrel used for barrel plating described in Patent Document 1. FIG. In the hexagonal cylindrical barrel 101, an electronic component element body and a conductive medium as an object to be plated are placed. Although not particularly illustrated, a large number of through holes are formed in the side surface of the barrel 101, and the barrel 101 is rotated around its axial direction while being immersed in the plating solution. A plating film is formed on the outer surface of the internal electronic component body by applying an electric field from the power supply terminals 102 and 103 while rotating the barrel 101.

In addition, although the front-end | tip part of the said electric power feeding terminals 102 and 103 is exposed in order to perform electric power feeding, it is normal that parts other than a front-end | tip part are coat | covered with the insulating material.
JP 2004-111534 A

  In recent years, electronic components have been downsized. Also in multilayer ceramic electronic components, the size of the ceramic sintered body on which the external electrode is formed is as small as 0.6 mm × 0.3 mm × 0.3 mm or 0.4 mm × 0.2 mm × 0.2 mm. It has become to. When attempting to form a plating film on such a small electronic component using a barrel plating apparatus, there is a case where the plating film is not formed on a necessary portion, unlike the conventional case. Alternatively, even if a plating film is formed at a necessary portion, there is a film that does not reach a desired film thickness.

  That is, when a conventional barrel plating apparatus as described in Patent Document 1 is used, if a reduction in the size of an electronic component is advanced, it may not be possible to reliably form a plating film with a desired film thickness on a necessary portion. there were.

  In the barrel 101 described in Patent Document 1, power supply terminals 102 and 103 are extended into the barrel 101 in order to apply an electric field during electroplating. FIG. 9 is a longitudinal sectional view schematically showing the barrel 101 described in Patent Document 1. As shown in FIG. The barrel 101 has first and second end faces 101a and 101b at both axial ends. First and second power supply terminals 102 and 103 are extended from the end faces 101 a and 101 b to the barrel 101. The first power supply terminal 102 includes a lead portion 102a extending in the axial direction from the inner surface of the end surface 101a, a lower extension portion 102b bent downward at the tip of the lead portion 102a, and a lower extension portion 102b. And a tip portion 102c extending from the lower end toward the center in the length direction of the barrel 101. Similarly, the second power supply terminal 103 also has a lead-out part 103a, a downward extension part 103b, and a tip part 103c. In the power supply terminals 102 and 103, the tip portions 102c and 103c are exposed to perform a power supply function, but the lead-out portions 102a and 103a and the lower extensions 102b and 103b are covered with an insulating material.

  In the barrel 101, as described above, since the power supply terminals 102 and 103 are extended to the center in the length direction of the barrel 101 in the barrel 101, in some cases, when the barrel 101 is rotated and plating is performed. In some cases, defective plating may occur in the electronic component body 104 as an object to be plated. That is, a large number of electronic component bodies and conductive media (not shown) are placed in the barrel 101, and the barrel 101 is immersed in the plating solution 105 during plating.

  However, when the barrel 101 is immersed in the plating solution 105, the barrel 101 is immersed in the plating solution 105 from above the surface of the plating solution 105. Therefore, the air existing in the barrel 101 may remain in the barrel 101 and a large air reservoir 106 may be formed above the inside of the barrel 101. When the air reservoir 106 is formed, the electronic component body 104 floats at the interface between the air reservoir 106 and the plating solution 105 during immersion. Further, in this state, when the barrel 101 is rotated and plating is performed, the electronic component body 104 moved upward with the rotation also moves to the interface between the air reservoir 106 and the plating solution 105, and then floats. As indicated by arrow A, it sometimes dropped downward from the interface.

  In this case, among the electronic component bodies 104 that have dropped down, some electronic component bodies 104 may be placed on the lead-out portions 102 a and 103 a of the power supply terminals 102 and 103. As described above, the lead portions 102a and 103a are covered with an insulating material. Therefore, in the electronic component base body 104 attached to the lead portions 102a and 103a of the power supply terminals 102 and 103, a plating film may not be formed on the attached portion.

  That is, in the conventional barrel plating method using a cylindrical barrel and the electronic component manufacturing method using the barrel plating method, it may be impossible to reliably form a plating film on a large number of objects to be plated.

  Accordingly, an object of the present invention is to provide a barrel plating apparatus that performs barrel plating while rotating a cylindrical barrel in a state in which the above-described disadvantages of the prior art are solved and the cylindrical barrel is immersed in a plating solution. An object of the present invention is to provide a barrel plating apparatus capable of reliably forming a plating film on the outer surface of a plated product, and a method for manufacturing an electronic component using the plating apparatus.

  A barrel plating apparatus according to the present invention includes a cylindrical barrel in which a plurality of objects to be plated and a plurality of conductive media are housed, a rotary drive source that rotates the barrel around the axial direction of the barrel, and the barrel And a barrel holding device for holding the barrel so that the barrel is rotated about the axial direction in a state where the axial direction of the cylinder is inclined with respect to the horizontal direction, and the cylindrical barrels are arranged at both ends in the axial direction. A power supply terminal that is extended into the barrel from the inside of at least one end face of the pair of end faces, and is bent so as to extend along the inner face of the end faces. It is characterized by providing.

  In a specific aspect of the barrel plating apparatus according to the present invention, the power supply terminal has a tip portion that extends inward from the end surface and extends downward in a direction along the inner surface of the end surface through a bent portion. And the distance from the inner surface of the said end surface to a bending part is made larger than the largest dimension in the external dimensions of the said to-be-plated thing and electroconductive media.

  In another specific aspect of the barrel plating apparatus according to the present invention, the power supply terminal is provided on both the first and second end faces.

  In still another specific aspect of the barrel plating apparatus according to the present invention, the power supply terminal is provided only on the first end face side of the first and second, and the barrel holding device causes the second of the barrel. The barrel is inclined so that the end face of the first end face is higher than the first end face.

  In still another specific aspect of the barrel plating apparatus according to the present invention, the base end portion fixed to the inner surface of the end surface of the power supply terminal is set to a position shifted from the rotation center of the end surface.

  An electronic component manufacturing method according to the present invention uses a barrel plating apparatus configured according to the present invention, and a plurality of electronic component bodies and a plurality of conductive media are provided in the cylindrical barrel. A step of storing, and a step of performing barrel plating by immersing the barrel in a plating solution and rotating the barrel with the rotational drive source in a state where the axial direction of the barrel is inclined.

  In a specific aspect of the method for manufacturing an electronic component according to the present invention, the inclination angle of the barrel with respect to the horizontal direction in the axial direction is in a range of 2 ° to 30 °.

  In another specific aspect of the method for manufacturing an electronic component according to the present invention, a plurality of floating bodies floating in a plating solution are introduced into the barrel during barrel plating.

  A barrel plating apparatus according to the present invention includes a cylindrical barrel, a rotational drive source that rotates the barrel around the axial direction of the barrel, and the barrel around the axial direction in a state where the axial direction of the barrel is inclined with respect to the horizontal direction. And a barrel holding device for holding the barrel so as to rotate. Therefore, in the barrel plating, the barrel plating can be performed while being rotated by the rotary drive source in a state where the barrel is inclined with respect to the horizontal direction while being immersed in the plating solution.

  In this case, the power supply terminal is extended into the barrel from the inner side of at least one of the pair of end faces, but the power supply terminal is bent so as to extend along the inner surface of the end face. Even if the object to be plated falls from below, the object to be plated is difficult to be placed on the power supply terminal. That is, since the tip end portion of the power feed terminal is bent downward along the inner surface rather than the portion positioned below the base end portion attached to the end face of the power feed terminal, In the portion extended along the inner surface, the object to be plated is difficult to be placed.

  In the power supply terminal, the tip portion is exposed to perform a power supply function, but other portions such as a lead portion drawn out from the end face to the inside are covered with an insulating material.

  Therefore, even if immersed in the plating solution, an air pool is generated in the upper part of the barrel, and after the object to be plated has moved to the interface between the air pool and the plating solution, the object to be plated has fallen downward from the interface. However, it is difficult to place an object to be plated on the lead-out portion of the power supply terminal. Therefore, poor plating due to the inability to supply power to the object to be plated is unlikely to occur. Therefore, it is possible to reliably form a plating film on a large number of objects to be plated.

  The power supply terminal has a tip portion extending inward from the end surface and extending in a direction along the inner surface of the end surface through the bent portion, and the distance from the inner surface of the end surface to the bent portion is determined by If the outer dimension of the conductive medium is larger than the maximum dimension, the inner surface of the end surface and the bent portion of the power supply terminal do not hinder the stirring of the object to be plated and the conductive medium. Variation in thickness can be suppressed.

  In the present invention, the power supply terminal may be provided on both the first and second end faces. In that case, plating can be performed by applying an electric field from a power supply terminal provided on the first and second end faces.

  Further, the power supply terminal may be provided only on the first end face side of the first and second end faces. In that case, it is preferably inclined by the barrel holding device so that the second end surface of the barrel is positioned higher than the first end surface. In this case, even if an air pool is generated upward in the barrel while the plating solution is immersed, the air pool is located on the second end face side. On the second end face side, since the power supply terminal does not exist below the air reservoir, even if the object to be plated that has drifted at the interface between the air reservoir and the plating solution falls downward, the power supply terminal does not exist below. Since it does not exist, poor plating due to adhesion between the power supply terminal and the object to be plated is more unlikely to occur.

  In addition, when the base end portion fixed to the inner surface of the end surface of the power supply terminal is shifted from the center of rotation of the end surface, even if the object to be plated rides on the base end portion of the power supply terminal, the shift is performed. As the distance increases, the plating object flows more easily from the power supply terminal due to the flow of the plating solution by rotation. Accordingly, plating defects can be further reliably reduced. Note that the greater the distance from the extraction position of the base end portion to the center of rotation of the end face (the greater the shift amount), the stronger the plating solution flow, so that the object to be plated falls more from the power supply terminal. It becomes easy.

  In the electronic component manufacturing method according to the present invention, the electronic component is manufactured using the barrel plating apparatus of the present invention. Then, a plurality of electronic component bodies and a plurality of conductive media are placed in a cylindrical barrel, the barrel is immersed in a plating solution, and the barrel is tilted with respect to the horizontal direction to rotate. Barrel plating is performed by rotating the barrel with a source. Therefore, even if an air puddle is generated in the upper part of the barrel, even if the object to be plated captured at the interface between the air puddle and the plating solution falls downward with the flow of the plating solution due to the rotation of the barrel, the power supply Since it is difficult to place the electronic component body on the terminal, it is possible to reduce plating defects due to contact between the electronic component body and the power supply terminal.

  When the inclination angle of the barrel in the axial direction is in the range of 2 ° or more and 30 ° or less, it is possible to more reliably reduce plating defects due to adhesion between the object to be plated and the power supply terminal.

  In the case of barrel plating, when a plurality of floating bodies floating in the plating solution in the barrel are introduced, even if an air pool is generated inside the barrel, the floating body floats at the interface between the air pool and the plating solution. Therefore, it is difficult for the electronic component body to be captured at the interface. Therefore, since the electronic component element body surely falls downward, plating defects due to floating at the interface of the electronic component element body can be reduced.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

  FIG. 4 is a schematic front view for explaining a barrel plating apparatus according to an embodiment of the present invention. The barrel plating apparatus 1 has a cylindrical barrel 2. The barrel 2 has a cylindrical shape, similar to the barrel 101 of the conventional barrel plating apparatus shown in FIG. In the present embodiment, the barrel 2 has a hexagonal cylindrical shape. But the cross-sectional shape of the barrel 2 is not limited to a hexagon, and may be another polygon.

  A plurality of through holes 2 a are formed on the outer peripheral side surface of the barrel 2, that is, six side surfaces. The through-hole 2 a is provided for communicating the inside of the barrel 2 with the outside of the barrel 2.

  In addition, the through-hole 2a should just be formed in the side surface at least. Therefore, the through holes 2 a may be formed on a pair of end surfaces located at both ends of the six side surfaces of the barrel 2.

  On the other hand, the barrel 2 is rotatably supported by the support member 3. The support member 3 has a pair of support plates 4 and 5. The support plates 4 and 5 are arranged so as to extend in the vertical direction. The support plates 4 and 5 are provided with sleeves 4a and 5a in order to rotatably support the barrel 2. The barrel 2 is rotatably supported by the sleeves 4a and 5a.

  The barrel 2 is arranged so that its axial direction extends in a direction connecting the support plates 4 and 5. As shown in FIG. 4, in the initial state, the support plates 4 and 5 extend in the vertical direction, and therefore the axial direction of the barrel 2 coincides with the horizontal direction.

  On the other hand, a cathode terminal 6 as a power supply terminal is attached to the sleeve 4a. The cathode terminal 6 extends from the end surface 2b of the barrel 2 into the barrel 2 via the sleeve 4a. The cathode terminal 6 is provided in order to pass a current from the anode during plating, and the portion of the cathode terminal 6 extending into the barrel constitutes the cathode.

  A sleeve 5a is arranged on the surface opposite to the sleeve 4a, and a cathode terminal 16 as the other power supply terminal is extended from the other end surface 2c of the barrel 2 into the barrel 2 via the sleeve 5a. Yes.

  A gear 7 is disposed between the support plate 4 and the barrel 3. The gear 7 is attached to the barrel 2 so as to rotate integrally with the barrel 2, and rotates together with the barrel 2 around the axial center of the barrel 2. A rod 8 is rotatably mounted between the support plates 4 and 5. A gear 9 is provided integrally with the rod 8. The gear 9 is configured to rotate with the rod 8 and is meshed with the gear 7 described above.

  Further, a motor 11 constituting a rotational drive source is attached between the support plates 4 and 5. A gear 13 is integrally provided on the rotating shaft 12 of the motor 11. The gear 13 is meshed with the gear 9 described above. Therefore, when the motor 11 is operated and the rotating shaft 12 is rotated, the barrel 2 can be rotated around the axial direction accordingly.

  The rotational drive source for rotating the barrel 2 around its axial direction is not limited to the structure in which the motor 11 and the gears 7, 9, 13 are combined. For example, the rotating shaft of the motor 11 may be directly connected to the barrel 2, or the motor and the barrel 2 may be connected using a power transmission mechanism such as an endless belt instead of the plurality of gears.

  As shown in FIG. 4, a connecting bar 14 that connects the support plates 4 and 5 is bridged above the support plates 4 and 5. A holding plate 15 is disposed above the connecting bar 14. Legs 15 a and 15 b are integrally provided on the lower surface of the holding plate 15. The leg portion 15a is disposed on the support plate 4 side, and the leg portion 15b is disposed on the support plate 5 side. The connecting bar 14 is fixed to the leg portions 15a and 15b.

  On the other hand, the holding plate 15 is connected to a holding rod 17 extending in the vertical direction so as to be rotatable about a shaft 15c. The holding rod 17 is connected to a reciprocating drive source 18 schematically shown, and is configured to move in the vertical direction by driving the reciprocating drive source 18. That is, the barrel 2 supported by the support members 4 and 5 by the barrel moving device including the holding rod 17 and the reciprocating drive source 18 is in the first state shown in FIG. Thus, it is configured to be movable between the second state immersed in the lower plating solution.

  The reciprocating drive source 18 can be constituted by a combination of a rotational driving source such as a motor and a power conversion mechanism that changes the rotational driving force into a reciprocating driving force, or a reciprocating driving source such as a hydraulic cylinder or an air cylinder. That is, the mechanism of the reciprocating drive source 18 is not particularly limited.

  Further, the lower end of the cylinder rod 19 a of the air cylinder 19 is connected to the upper surface of the holding plate 15. By driving the air cylinder 19, the cylinder rod 19a can be partially pulled into the cylinder body 19b from the initial state shown in FIG.

  As shown in FIG. 5, when the cylinder rod 19a is in a retracted state, the holding plate 15 is moved toward the cylinder body 19b. As a result, since the holding plate 15 is connected to the holding rod 17 via the shaft 15c, the holding plate 15 moves upward on the cylinder rod 19a side, and the leg portion 15b side of the holding plate 15 is pulled upward. . That is, the holding rod 17 extends in the vertical direction, and the angle θ between the holding rod 17 and the main surface of the holding plate 15 is smaller than 90 °. Accordingly, the support plates 4 and 5 are also inclined, and the axial direction of the barrel 2 supported between the support plates 4 and 5 is inclined by an angle α = (90 ° −θ) with the horizontal direction. become. An angle α between the axial direction of the barrel 2 and the horizontal direction is defined as an inclination angle. In this embodiment, the inclination angle α is larger than 0 °, that is, the axial direction of the barrel 2 is inclined with respect to the horizontal direction. It can be reliably discharged out of the barrel. Preferably, the inclination angle is in the range of 2 ° to 30 °, as will be described later.

  In FIG. 5, the cylindrical barrel 2 is tilted as described above while being immersed in the plating solution 22. However, the barrel 2 is tilted before being immersed in the plating solution 22. It may be carried out after the plating solution is immersed. The support plates 4 and 5, the rod 14, the holding plate 15, the shaft 15 c, the holding rod 17, the air cylinder 19, and the like form an inclination device corresponding to the barrel holding device in the present invention. However, the tilting device that tilts the barrel 2 with respect to the horizontal direction in the axial direction is not limited to the illustrated structure.

  A plating tank 21 is disposed below the support member 3. A plating solution 22 is injected into the plating tank 21. Note that an anode (not shown) is disposed in the plating tank 21. The upper surface of the plating solution 22 is opened, and the support member 3 is disposed above the plating solution 22.

  Next, the details of the barrel 2 will be described with reference to FIGS. FIGS. 1A and 1B are a schematic longitudinal sectional view and a transverse sectional view for explaining the internal structure of the barrel 2.

  The barrel 2 has first and second end faces 2b and 2c at both ends in the axial direction. The barrel 2 is rotated around the axial direction, and as described above, the barrel 2 is configured to be rotated in a state inclined at a predetermined angle from the horizontal direction.

  The first cathode terminal 6 extends from the first end surface 2 b and the second cathode terminal 16 extends from the second end surface 2 c to the inside of the barrel 2. As for the 1st cathode terminal 6, the base end 6a is pulled out from the center of the inner surface of the end surface 2b. And it bend | folds in the direction in alignment with the inner surface of the end surface 2b in the bending part 6b. That is, the first cathode terminal 6 includes an inward protruding portion located between the base end 6a and the bent portion 6b, and a distal end portion extending from the bent portion 6b in a direction along the inner surface of the end surface 2b. 6c. The cathode terminal 6 serving as a power supply terminal is configured such that the tip portion 6c is exposed and performs a power supply function, but the remaining portion is covered with an insulating material. That is, the inward protruding portion is covered with an insulating material. Therefore, when the electronic component body 31 rides on the inward projecting portion, plating is not performed on the adhesion portion between the electronic component body 31 and the inward projecting portion.

  Similarly, the second cathode terminal 16 has the base end 16a drawn out from the rotation center of the inner surface of the second end surface 2c, and is bent so as to extend in the direction along the inner surface of the end surface 2c via the bent portion 16b. Yes. That is, it has the inward protrusion part between the base end 16a and the bending part 16b, and the front-end | tip part 16c.

  Next, a method for manufacturing an electronic component using the barrel plating apparatus of the present embodiment will be described with reference to FIGS. 1 and 4 and FIGS.

  In the electronic component manufacturing method of the present embodiment, a plating film is formed on the electronic component element body 31 shown in FIG. The electronic component body 31 includes a sintered body 32 that constitutes a multilayer ceramic capacitor. In the sintered body 32, the internal electrodes 33a to 33i are arranged so as to overlap with each other through a ceramic layer. The internal electrodes 33a, 33c, 33e, 33g, 33i are drawn out to the end face 32a, and the internal electrodes 33b, 33d, 33f, 33h are drawn out from the end face 32b. Base electrode layers 34a and 35a formed by baking an Ag paste are formed so as to cover the end faces 32 and 32a.

  As shown in FIG. 1A, a large number of electronic component bodies 31 are put into the barrel 2 described above. In addition to the electronic component body 31, a plurality of conductive media 23, such as steel balls, are put into the barrel 2. On the other hand, the barrel 2 into which the electronic component body 31 and the conductive medium are put is disposed above the plating solution 22 in the initial first state, as shown in FIG. In this state, the support plates 4 and 5 are disposed so as to extend in the vertical direction, and the above-described axial angle of the barrel 2 in the axial direction is 0 °. That is, the axial direction of the barrel 2 extends in the horizontal direction.

  Next, the cylinder 19 is driven, a part of the cylinder rod 19a is pulled in, and the holding plate 15 is tilted as shown in FIG. As a result, the barrel 2 is inclined so that the axial angle of the barrel 2 is greater than 0 °.

  Next, the reciprocating drive source 18 is driven, the holding rod 17 is moved downward, and the barrel 2 is moved downward to enter the second state.

  The step of inclining the barrel 2 so that the axial angle of the barrel 2 becomes larger than 0 ° is performed prior to the downward movement of the barrel 2 by the reciprocating drive source 18. However, when the barrel 2 is moved downward by the reciprocating drive source 18, the cylinder 18 may be simultaneously driven to tilt the barrel 2. In any case, the axial angle of the barrel 2 may be changed while the barrel 2 is immersed in the plating solution 22. As a result, as shown in FIG. 5, the barrel 2 is immersed in the plating solution 2 in an inclined state.

  When the barrel 2 is immersed in the plating solution 22 in an inclined state, the air in the barrel 2 moves upward and is discharged to the outside from the through hole 2a. In this case, when the barrel 2 is inclined, the side surface portion 2b located above the side surface of the barrel 2 is inclined with respect to the horizontal direction at the position shown in FIG. It becomes easy to move inside the portion 2b, and it is quickly discharged from the through hole 2a opened in the side surface portion 2b.

  That is, when the side surface portion 2b is extended in the horizontal direction, the bubbles in contact with the inner surface of the side surface portion 2b are difficult to move and may remain. On the other hand, when the side surface portion 2b is inclined, air easily moves along the inner surface of the side surface portion 2b and is easily discharged to the outside from the through hole 2a.

  In this state, plating can be performed by passing a current between the first and second cathode terminals 6 and 16 and the anode immersed in the plating solution. In this case, since the internal air is easily discharged from the through hole 2a, it is difficult for an air reservoir to occur. Therefore, it is difficult for the electronic component element body as the object to be plated to be captured at the interface between the air reservoir and the plating solution, and the plating film can be reliably formed on the numerous electronic component element bodies 31.

  In addition, even if air remains inside the barrel 2 and the air reservoir B exists above the inside of the barrel 2 as shown in FIG. A plating film can be reliably formed on the outer surface of the film. That is, when the air reservoir B exists, the electronic component element body 31 is easily captured at the interface between the air reservoir B and the plating solution 22. With the rotation, the captured electronic component body 31 falls downward as indicated by an arrow C in FIG. However, the axial direction of the barrel 2 is inclined as described above, and the first and second cathode terminals 6 and 16 as power supply terminals are bent downward along the inner surfaces of the end faces 2b and 2c. Yes. Therefore, it is difficult to place the electronic component body 31 that has dropped from above on the cathode terminals 6 and 16.

  As shown in FIG. 9, in the conventional barrel plating apparatus, the dropped electronic component body is placed on the power supply terminal, and the plating failure tends to occur due to the contact between the two. On the other hand, in this embodiment, plating defects due to contact between the power supply terminal and the electronic component body 31 can be reliably suppressed.

  Therefore, even if the air pool B is generated in the inclined barrel 2, it is possible to reliably reduce plating defects.

  In this way, Ni plating films 34b and 35b shown in FIG. 3 are formed. Thereafter, the Sn plating films 34c and 35c are formed on the Ni plating films 34b and 35b by exchanging the plating solution. Therefore, as shown in FIG. 3, external electrodes 34 and 35 in which Ni plating films 34b and 35b and Sn plating films 34c and 35c are laminated are formed on the base electrode layers 34a and 35a. A multilayer ceramic capacitor 37 is obtained as described above.

  Preferably, the inwardly protruding dimensions of the inwardly protruding portions of the cathode terminals 6 and 16, that is, the dimension X extending from the base ends 6a and 16a to the bent portions 6b and 16b are the electronic component body 31 as the object to be plated and It is desirable that the outer dimension of the conductive medium is larger than the maximum dimension, thereby preventing the electronic component body 31 from riding on the inward projecting portion.

  6A to 6C are a longitudinal sectional view for explaining a modification of the barrel plating apparatus of the above embodiment, a perspective view schematically showing a first end face inner portion, and a transverse sectional view.

  In the barrel plating apparatus of this modification, the barrel 42 has first and second end faces 42a and 42b at both ends in the axial direction. Here, the first cathode terminal 46 as a power supply terminal is provided only on the inner surface of the first end face 42a. That is, no cathode terminal is provided on the second end face 42b side. The barrel 42 is rotated in an inclined state so that the second end face 42b side is higher than the first end face 42a side. Therefore, even if an air pool occurs, the air pool B is positioned on the second end face 42b side. Therefore, even if the electronic component body 31 captured at the interface between the air reservoir B and the plating solution 22 falls downward, it does not fall to the first end face 42a side. Therefore, it is difficult to place the electronic component body 31 on the cathode terminal 46 serving as a power supply terminal, so that it is possible to reduce plating defects more reliably.

  In the present modification, as shown in FIG. 6B, the base end 46a of the cathode terminal 46 is shifted from the rotation center of the first end face 42a. Accordingly, the base end 46a of the cathode terminal 46 is shifted from the center of rotation of the first end face 42a and pulled out from the first end face 42a, so that the electronic component element body 31 rides on the inward projecting portion. Even if it rotates, the flow of the plating solution in the rotation direction occurs, and the electronic component element adhering to the inward protruding portion is dropped, so that the plating defect due to the adhesion between the electronic component element 31 and the inward protruding portion is caused. It can be certainly reduced.

  In the above-described embodiment and the modification shown in FIG. 6, the inclination angle of the barrels 2 and 42 is preferably in the range of 2 ° to 30 °. If the inclination angle is less than 2 °, the air that may exist in the barrels 2 and 42 cannot be quickly moved upward on the upper end face side, and electrons trapped at the interface between the air pool B and the plating solution 22 are not captured. There is a possibility that the component body 31 easily falls on the cathode terminal. On the other hand, when the angle exceeds 30 °, when the electronic component body 31 trapped at the interface between the air reservoir B and the plating solution 22 falls, the cathode terminal on the first end face 2b, 42a side is reversed. There is a risk of getting on. Stirability deteriorates, and there is a possibility that defects such as film thickness variation deterioration and sticking between multiple plating products may increase.

  7 (a) and 7 (b) are a cross-sectional view and a vertical cross-sectional view for explaining still another modification of the barrel plating apparatus of the present invention. In this modification, a plurality of floating bodies 51 floating in the plating solution 22 are stored in the barrel 42. In other respects, the barrel 42 is the same as the barrel 42 shown in FIG. Thus, in the present invention, a plurality of floating bodies 51 may be suspended in the barrel 42. By floating such a floating body 51, the floating body 43 floats at the interface between the air pool B and the plating solution 22 even if the air pool B exists. Therefore, it is possible to reliably suppress the electronic component element body 31 from being captured by the interface, thereby reliably reducing plating defects. Such a floating body 51 is not particularly limited as long as it can float in the plating solution 22. Therefore, a floating body made of an appropriate material having a specific gravity lighter than that of the plating solution 22 may be used. More preferably, the floating body 51 desirably has a specific gravity smaller than that of the electronic component element body 31, whereby the proximity of the electronic component element body 31 to the interface can be more reliably prevented.

  In the above embodiment, the electronic component element body 31 for obtaining the multilayer ceramic capacitor is shown as an object to be plated. However, the barrel plating apparatus according to the present invention is not limited to the electronic component element body 31, It can also be used for plating an electronic component element body or an object to be plated other than the electronic component element body.

(A) And (b) is the longitudinal cross-sectional view and cross-sectional view for demonstrating the inside of the cylindrical barrel used for one Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS Front sectional drawing for demonstrating the electronic component element | base_body in which a plating film is formed in one Embodiment of this invention. 1 is a front sectional view showing a multilayer ceramic capacitor as an electronic component on which a plating film is formed in one embodiment of the present invention. In the barrel plating apparatus which concerns on one Embodiment of this invention, front sectional drawing which shows the state before a barrel is inclined. The front sectional view for explaining the process of immersing in the state where the barrel was inclined in the plating solution in the manufacturing method of the electronic component of one embodiment of the present invention. (A) is a longitudinal cross-sectional view which shows the modification of the barrel used by this invention, (b) is a perspective view which shows the internal structure of the 1st end surface side, (c) is a cross-sectional view of this barrel. (A) And (b) is the cross-sectional view and longitudinal cross-sectional view for demonstrating the further another modification of the barrel-plating method in the barrel-plating apparatus used by this invention. The perspective view which shows the cylindrical barrel used for the conventional barrel plating apparatus. The schematic longitudinal cross-sectional view for demonstrating the problem in the conventional barrel plating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Barrel plating apparatus 2 ... Barrel 2a ... Through-hole 2b, 2c ... End surface 3 ... Support member 4,5 ... Support plate 4a, 5a ... Sleeve 6 ... Cathode terminal 6a ... Base end part 6b ... Bending part 6c ... Tip part 7 ... Gear 8 ... Rod 9 ... Gear 11 ... Motor 12 ... Rotary shaft 13 ... Gear 14 ... Connecting bar 15 ... Holding plate 15a, 15b ... Leg 15c ... Shaft 16 ... Cathode terminal 16a ... Base end 16b ... Bending part 16c ... Tip portion 17 ... Holding rod 18 ... Moving device 19 ... Cylinder 19a ... Cylinder rod 19b ... Cylinder body 21 ... Plating tank 22 ... Plating solution 23 ... Conductive medium 31 ... Electronic component body 32 ... Ceramic sintered body 32a, 32b ... End faces 33a to 33i ... internal electrodes 34, 35 ... external electrodes 34a, 35a ... base electrode layers 34b, 35b ... Ni Film 34c, 35c ... Sn plating film 37 ... laminated ceramic capacitor 42 ... barrel 42a, 42b ... first and second end surfaces 46 ... cathode terminal 46a ... base portion 46b ... bent portion 46c ... tip 51 ... float

Claims (8)

A cylindrical barrel in which a plurality of objects to be plated and a plurality of conductive media are stored,
A rotational drive source for rotating the barrel around the axial direction of the barrel;
A barrel holding device for holding the barrel so as to rotate the barrel around the axial direction in a state where the axial direction of the barrel is inclined with respect to the horizontal direction;
The cylindrical barrel has a pair of end faces disposed at both axial ends;
Barrel plating characterized by further comprising a power supply terminal that extends into the barrel from the inner side of at least one of the pair of end surfaces, but is bent so as to extend along the inner surface of the end surfaces. apparatus.   The power supply terminal is extended downward in a direction along the inner surface of the end surface through the bent portion, an inward protruding portion extending inward from the end surface, a bent portion bent at the tip of the inner protruding portion, and The distance from the inner surface of the said end surface to a bending part is made larger than the largest external dimension among the external dimensions of the said to-be-plated thing and an electroconductive medium. Barrel plating equipment.   The barrel plating apparatus according to claim 1, wherein the power supply terminal is provided on both the first and second end faces.   The power supply terminal is provided only on the first end face side of the first and second end faces, and the barrel holding device causes the second end face of the barrel to be higher than the first end face. The barrel plating apparatus according to claim 1, wherein the barrel is configured so as to be inclined.   The base end portion fixed to the inner surface of the end face of the power feeding terminal is set to a position shifted from the rotation center of the end face. Barrel plating equipment. An electronic component manufacturing method using the barrel plating apparatus according to any one of claims 1 to 5,
A step of storing a plurality of electronic component bodies and a plurality of conductive media in the cylindrical barrel;
A method of manufacturing an electronic component, comprising: dipping the barrel in a plating solution, rotating the barrel with the rotary drive source in a state where the axial direction of the barrel is inclined, and performing barrel plating.   The method for manufacturing an electronic component according to claim 6, wherein an inclination angle of the barrel in the axial direction is in a range of 2 ° to 30 °. The method for manufacturing an electronic component according to claim 6 or 7, wherein a plurality of floating bodies floating in a plating solution are introduced into the barrel during the barrel plating.

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