JP5435355B2 - Plating equipment - Google Patents

Description

  The present invention relates to a plating apparatus for base particles having conductivity on the surface.

  As an example of a technique for plating base material particles having conductivity on the surface, solder is coated on the surface of a core ball mainly composed of Cu and solder-coated Cu core ball (hereinafter abbreviated as Cu core ball). There is technology to form. In order to clarify the problems of the prior art, the plating technique will be described using a Cu core ball as an example, but the present invention is not limited to the Cu core ball.

  In recent semiconductor packages such as BGA (Ball Grid Array) and CSP (Chip Scale Package) where high-density mounting is progressing due to multi-pitch and narrow pitch, small-diameter Cu core balls are applied as bumps for input / output terminals. . Since the Cu core ball does not melt during reflow, it can maintain a certain distance between the semiconductor element and the substrate, and ensure connection reliability against thermal cycle loads caused by starting and stopping of the semiconductor element. Can do.

  As a Cu core ball manufacturing technique, a barrel electroplating method is known in which a core ball is housed in a barrel having a large number of openings through which a plating solution can flow, and the barrel is placed in a plating bath and rotated to coat the solder. . However, particularly when a small-diameter Cu core ball having a diameter of 100 μm or less is manufactured, the core ball is not sufficiently stirred by the rolling of the core ball accompanying the rotation of the barrel. As a result, the core balls are connected and aggregated via the plating layer, the surface of the plating layer is roughened, the thickness of the plating layer is partially uneven, and the yield is reduced. .

  An example of a technique for solving the problem of the barrel type electroplating method is described in Patent Document 1. In Patent Document 1, in order to obtain a sufficient and uniform plating layer in a short time, “the object to be plated is placed between the lower surface of the outer peripheral portion of the bottom-opened bowl-shaped resin dome with the upper end open and the upper surface of the outer peripheral portion of the resin bottom plate. A contact ring that is pressed during rotation and a porous ring through which the treatment liquid circulates are integrally joined to form a cell, and the cell is supported on the lower surface of the central portion of the conductive rotary plate that supports the cell so that it cannot rotate relative to the contact ring. `` Rotary plating device for small items, fixing the upper end of a vertical conductive drive shaft, pressing a contact brush on the shaft and connecting it to the negative pole, placing an anode basket in the dome, and covering the cell '' Is described. According to the rotary plating apparatus having such a configuration, the object to be plated accommodated in the cell is forcibly pressed against the contact ring by the action of the centrifugal force generated by the rotation of the cell, and the rotation and stop or deceleration of the cell. By repeating the above, it is described that the mixture is uniformly mixed, the plating solution on the surface of the object to be plated is renewed actively, and a plating layer having a uniform thickness can be formed.

  However, the rotary plating apparatus of Patent Document 1 has a problem in terms of efficiency in industrial production. That is, this rotary plating apparatus needs to repeatedly rotate, stop, or decelerate the cells in order to stir the object to be plated and sufficiently distribute the plating solution to the surface. And, the actual plating process to the object to be plated is performed only while the object is in contact with the contact ring by centrifugal force and centrifugal force, and is not performed while stopping or decelerating. The overall manufacturing time is longer than the plating time. Further, since the stirring force of the ball does not act during the plating process, especially in the case of a small-diameter Cu core ball having a diameter of 100 μm or less used for a semiconductor package, the core ball is agglomerated in the cell, and the plating The smoothness of the surface of the treated Cu core ball also deteriorates. In order to solve this aggregation, there is a method in which the rotation, stop or deceleration of the cell is frequently repeated, but there arises a problem that the plating efficiency is further lowered.

  Another example of a technique for solving the problem of the barrel type electroplating method is described in Patent Document 2. In Patent Document 2, the purpose is to prevent deformation or the like of a workpiece having a particularly easy-to-bend property, and “a plating tank having an upper surface opening and a detachable lid for closing the upper surface opening of the plating tank are provided. And having a cathode on the bottom surface of the plating tank, an anode on the back surface of the detachable lid, and a nozzle for spraying a plating solution directed toward the inner surface of the peripheral wall on the peripheral wall along the bottom surface of the plating tank. A plating apparatus is described. And in patent document 2, by employ | adopting such a structure, the workpiece | work thrown in in the plating tank turns into the inside of a plating tank with the plating liquid injected from an injection nozzle, and a plating process is given accompanying the rotation. For this reason, it is described that there is no collision or the like that causes bending or deformation, and that the plating process can be completed while keeping all the workpieces in their original shapes.

  However, the plating apparatus disclosed in Patent Document 2 is insufficient in that a plating layer having a uniform thickness is formed on the substrate particles. That is, when the substrate particles are plated by the plating apparatus of Patent Document 2, the substrate particles swirl while being stirred by the plating solution swirling in the plating tank, but the particles move on the liquid flow, The probability that the electrode and the particles arranged on the surface are in contact with each other is small, and the probability is not uniform for each particle. As a result, there may be a problem that the thickness of the plating layer differs for each base material particle.

  Furthermore, in Patent Document 3 below, as an apparatus for coating a metal with a particle size of 0.1 μm to 10 μm on the surface of a fine powder such as an inorganic substance uniformly and in high yield by electroplating, “ A cylindrical container having a longitudinal axis for containing the plating solution, a cathode plate disposed on the bottom of the container with the conductive surface laterally, an anode disposed near the liquid surface of the plating solution, and the cathode plate A power supply device that applies a predetermined potential to the anode, a suction pipe having a suction opening in the liquid between the cathode plate and the anode, and a discharge device for discharging into the liquid between the cathode plate and the anode A discharge pipe having an opening, a fluid circulation path leading from the suction pipe to the discharge pipe, and a fluid circulation pump interposed in the circulation path. The discharge opening of the discharge pipe is connected to the conductive surface of the cathode plate. The suction opening of the suction pipe is further lower than the lower end of the anode. The conductive fine powder having a particle diameter in the range of 0.1 μm to 10.0 μm is continuously collided with the cathode plate while circulating through the circulation path together with the plating solution. A fine powder electroplating apparatus "is disclosed. And according to such a plating apparatus, the fine powder is suspended in the electroplating solution with a predetermined suspension concentration, and a fine powder suspension having a predetermined direction and speed is forcibly formed in the plating solution, Since the fine powder suspension flow is circulated and collided with the cathode plate with a predetermined velocity component without substantially contacting the anode, it is possible to perform electroplating on the surface of each fine powder uniformly and with high yield. It is described as.

  However, even with the plating apparatus disclosed in Patent Document 3, the fine powder only flows on the fine powder suspension flow, and therefore the probability of contact with the cathode plate is not uniform among the fine powders. For the same reason as described above, it is insufficient in that a plating layer having a uniform thickness is formed on individual substrate particles.

JP-A-8-239799 Japanese Utility Model Publication No. 7-6267 Japanese Patent Laid-Open No. 1-272792

  The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a plating apparatus capable of efficiently forming a plating layer having a uniform thickness on the surface of conductive base particles. It is said.

  A plating apparatus according to the present invention for solving the above-mentioned problems is a plating apparatus for base particles having conductivity on the surface, and is erected along the bottom surface that can be circulated while the base material particles are in contact with the periphery of the bottom surface. A plating tank having a plating chamber that can store a particle group including the base material particles and a plating solution, and a supply port that opens upward from the bottom surface of the plating chamber. A plating solution supply pipe for supplying a plating solution from the supply port so as to swirl along the wall surface; a plating solution discharge pipe having a discharge port opened to the plating chamber; and the base material disposed on the bottom surface of the plating chamber. It is a plating apparatus having a cathode in contact with particles, an anode arranged at a position immersed in a plating solution stored in the plating chamber, and a power source connected to the cathode and the anode.

  Such a plating apparatus has the following effects. That is, the plating solution supplied from the supply port of the plating solution supply pipe flows down toward the bottom surface while turning along the peripheral wall surface of the plating chamber. Then, when the plating chamber is filled with the plating solution, it is discharged from the plating solution discharge pipe through the discharge port opened to the plating chamber, and the plating chamber is always kept fresh by supplying new plating solution from the plating solution supply pipe. Filled with.

  The swirling and flowing plating solution that has reached the bottom surface of the plating chamber causes the particle group stored in the plating chamber to swirl while contacting the bottom surface of the plating chamber. The base material particles in contact with the cathode on the bottom surface are subjected to a plating process with the anode disposed at a position immersed in the plating solution, and a plating layer is formed on the surface of the base material particles. Here, the particles are swirled on the bottom surface while rolling while contacting the bottom surface while being mixed with each other without being dispersed by the swirling flowing plating solution. Therefore, the aggregation of the base particles is suppressed, and the parts on the surface of the base particles are equally exposed to the plating solution, and as a result, a plating layer having a uniform thickness is formed. In addition, the particle | grains which started the turning motion will continue a turning motion, repeating intermittent contact with the bottom face, without floating.

  Furthermore, since the substrate particles are rolled while being brought into contact with the bottom surface of the plating chamber by the swirling flow of the plating solution, the probability that the substrate particles are in contact with other substrate particles is increased. It is electrically connected with high frequency, and it is possible to perform a process close to continuous plating, and it is possible to efficiently form a plating layer on the base particles, and further, a plating layer formed by contact between the base particles Is smoothened, and a plated layer having a very smooth surface and a uniform thickness can be formed.

  As described above, according to the plating apparatus of the present invention, it is possible to solve the problems of the prior art and to efficiently form a plating layer having a smooth surface and a uniform thickness on the surface of conductive base particles. The object of the present invention to provide a plating apparatus can be achieved. In addition, the preferable aspect and effect of the said plating apparatus are demonstrated in detail below.

It is a figure which shows schematic structure of the plating apparatus of the 1st embodiment concerning this invention. It is a top view of the plating apparatus of FIG. 1 and the plating apparatus of the preferable aspect. It is the elements on larger scale of the plating apparatus of another preferable aspect of the plating apparatus of FIG. It is the elements on larger scale of the plating apparatus of another preferable aspect of the plating apparatus of FIG. It is a front view of the plating apparatus of another preferable aspect of the plating apparatus of FIG. It is an enlarged front view of the plating apparatus of another preferable aspect of the plating apparatus of FIG. It is a perspective view of the plating apparatus of the 2nd embodiment concerning the present invention. It is a figure which shows schematic structure of the other example of the plating apparatus of a 2nd embodiment. It is a perspective view of the plating apparatus of the 3rd embodiment concerning the present invention. It is a perspective view of the plating apparatus of the 4th embodiment concerning the present invention. It is a figure explaining operation | movement of the plating apparatus of FIG. It is a figure which shows schematic structure of the other example of the plating apparatus of a 4th embodiment. It is a figure which shows schematic structure of the plating apparatus of the 5th embodiment concerning this invention. It is a figure explaining the behavior during plating of a core ball. It is a figure explaining the Example of the plating apparatus of FIG. It is another figure explaining the Example of the plating apparatus of FIG.

  Hereinafter, a plating apparatus according to the present invention will be described based on first to fifth embodiments with reference to the drawings. In the following embodiment, a description will be given of a plating apparatus that coats the surface of a spherical core ball mainly composed of Cu, which is a base particle, with a plating layer mainly composed of Sn, but the present invention is limited to this. Without forming a metal coating layer on the surface of resin or ceramics particles or other conductive particles on the surface without electroless plating, such as nickel or the like. Can be applied. Further, the present invention can be applied not only to spherical base particles such as a core ball, but also to, for example, needle-like base particles having a major axis and a minor axis, and amorphous base particles having no shape characteristics. Furthermore, each component of the plating apparatus described below can be used alone or in appropriate combination.

[First Embodiment]
As shown in FIG. 1 which is a front view showing a schematic configuration of the plating apparatus of the first aspect and FIG. 2A which is a plan view of the state where the sealing lid 1L in FIG. 1 is removed, the plating apparatus 1 includes a main body portion. 1a, a plating solution circulation means 1b connected to the main body 1a via a plating solution supply pipe 1e and a plating solution discharge pipe 1c, and a direct current power supply circuit 1h are provided as basic structures, and a core ball supply means 1g as a more desirable structure. , A vibration means 1i and a magnetic force generation means 1s are provided.

  In the main body 1a, reference numeral 1j denotes a plating tank in which a plating chamber 1m having a circular bottom surface 1p and a frustoconical peripheral wall surface 1q having a diameter reduced toward the bottom surface 1p is formed. A plating tank 1j made of a resin or the like, which is a non-conductive insulator having corrosion resistance to the plating solution, is closely attached to a bowl-shaped container 1k having an upper opening and an upper surface of the container 1k so as to close the upper opening. And a sealed lid 1L. A space formed by the container 1k and the sealing lid 1L constitutes a plating chamber 1m, and a ball group (particle group) 9 including a large number of core balls 91 and a predetermined amount of plating solution L are stored in the plating chamber 1m. .

  The plating solution supply pipe 1e is horizontally connected at one end thereof to the plating tank 1j so that the axis of the plating solution extends along the tangential direction of the peripheral wall 1q of the plating chamber 1m, and the plating solution supply port 1f opens above the plating chamber 1m. One end of the plating solution discharge pipe 1c is connected to the plating tank 1j so that the plating solution discharge port 1d opens in the plating chamber 1m coaxially with the axial center of the plating chamber 1m at the center of the sealing lid 1L. Is connected to the plating solution circulating means 1b. The plating solution circulation means 1b includes a plating solution storage tank, a plating solution circulation pump, a plating solution purification filter, a flow rate control valve, and the like (not shown). The plating solution L sent from the plating solution circulation means 1b is: It flows through the plating solution supply pipe 1e and is supplied from the plating solution supply port 1f to the plating chamber 1m, and swirls down along the peripheral wall surface 1q of the plating chamber 1m as shown by a broken line a in FIGS. Further, the flow rate and flow rate of the plating solution L supplied to the plating chamber 1m can be changed over time by adjusting the plating solution circulation pump and the flow rate control valve of the plating solution circulation means 1b. The plating solution circulating means 1b may be configured not only to supply the plating solution L through the plating solution supply pipe 1e but also to be able to suck the plating solution L from the plating chamber 1m through the plating solution discharge pipe 1c. Further, a plurality of the plating solution supply pipes 1e may be provided. In this case, a plating solution supply pipe may be arranged on the same circumference of the peripheral wall surface 1q of the plating chamber 1m so that a plurality of plating solution supply ports 1f are opened at a constant angular pitch, for example, as shown in FIG. The plating solution supply pipe 22e may be arranged so that a plurality of plating solution supply ports 22f are opened along the spiral flow a of the plating solution L flowing down. With the above configuration, as shown in FIG. 1, the plating solution L spirally flows while swirling along the circumferential wall 1 q inclined downward, reaches the bottom surface 1 p of the plating chamber 1 m, and thereafter is shown by a broken line b in the figure. As shown, the flow increases and is discharged from the plating solution discharge pipe 1c through the plating solution discharge port 1d and returns to the plating solution circulation means 1b.

  The core balls 91 may be supplied to the plating chamber 1m each time by opening and closing the sealing lid 1L. However, as shown in FIG. 1, a predetermined number of core balls 91 are provided in the supply system constituted by the plating solution supply pipe 1e. Supply means 1g for cutting out 91 may be provided, and the core ball 91 together with the plating solution L may be supplied to the plating chamber 1m through the conduit of the plating solution supply pipe 1e. The specific configuration of the supply means 1g will be described in detail in the plating apparatus of the fourth aspect.

  Reference numeral 1n denotes a disc-shaped cathode disposed at the bottom of the container 1k, and the upper surface of the cathode 1n is configured to be the bottom surface 1p of the plating chamber 1m. The cathode 1n connected to the negative electrode of the DC power supply circuit 1h is made of, for example, stainless steel, titanium, platinum-plated titanium, or the like. The ball group 9 is swung by the plating liquid L swirling in the plating chamber 1m while being in contact with the bottom surface 1p in a predetermined range in the radial direction from the outer peripheral end, as indicated by reference numeral C in the figure. The ball 91 rolls on the bottom surface 1p while being stirred.

  Here, even if the cathode 3n is disposed so as to be exposed at a part of the bottom surface 3p of the plating chamber 1m as shown in FIG. 3 (a), the core disposed on the bottom surface 3p as shown in FIG. 3 (b). The cathode 3 m may be disposed so as to contact the ball 91. However, when the cathodes 3n and 3m are arranged so as to be in contact with only a small part of the large number of core balls 91, the core balls 91 not in contact with the cathodes 3n and 3m are in contact with the cores 3n and 3m. Since current is passed through the ball 91, the potential of the core ball 91 at a position away from the cathode 3n is lowered by the contact resistance between the core balls 91, the current density in the core ball 91 is lowered, and the plating efficiency is lowered. there's a possibility that. Therefore, when viewed in a plan view, the cathode preferably has a sufficient contact area with the ball group 9, and is preferably formed in a disk shape as in this embodiment. In this case, the container 1k itself may be formed of a cathode material, and a resin coating having corrosion resistance and insulation may be applied to the side surface of the container 1k so that the bottom surface of the container 1k functions as the cathode 1n.

  On the other hand, as shown in FIG. 1 and FIG. 2 (a), when all of the bottom surface 1p of the plating chamber 1m is constituted by the cathode 1n, the formation speed of the plating layer may be lowered. That is, since the ball group 9 swirls in a predetermined region C on the outer peripheral edge of the bottom surface 1p (the upper surface of the cathode 1n) with the plating solution L that swirls and flows, the central portion of the upper surface of the cathode 1n without the ball group 9 exists. This is also because the plating is deposited in vain. Therefore, as shown by reference numeral 2n in FIG. 2 (b) and FIG. 2 (c) which is a cross-sectional view along the center line, the cathode corresponds to the region in which the ball group 9 swivels and is located on the outer periphery of the bottom surface 2p. It is preferably provided in an annular shape, and the central portion 2z of the bottom surface 2p is preferably made of an electrically insulating material. In the case of FIGS. 2B and 2C, the central portion 2z is integrally formed with the container 1k. For example, the central portion 2z is formed separately from insulating ceramics and incorporated into the container 1k. You may do it.

  Furthermore, as shown in FIG. 2 (c), the cathode 2n is not only the first cathode 2y exposed so that its surface forms the same plane as the bottom surface 2p, but also its inner surface is the same as the peripheral wall 1q. You may equip the base end part of the container 1k with the 2nd cathode 2x exposed so that a surrounding surface may be formed. As shown in the figure, the cathodes 2x and 2y can be incorporated into the container 1k as a cathode 2n coupled at one end so as to have a cross-sectional cross section. By providing the second cathode 2x, the area of the cathode 2n with which the ball group 9 can contact can be increased, and a uniform plating layer can be formed on the core ball 91 while maintaining high plating efficiency. Is possible. In order to prevent the deposition of plating on the surface of the cathode 2n and increase the plating efficiency, the cathode 2n must be included in the range C in which the ball group 9 swirls as shown in FIG. 2 (c). Is desirable. Further, the cathode 2n shown in FIG. 2 (b) is formed in a continuous annular shape in the circumferential direction, but if it is formed in a substantially annular shape even if there is a discontinuous portion in part. Good.

  Furthermore, in order to improve the smoothness of the outer surface by sliding the outer peripheral surfaces of the plating layers formed on the surfaces of the core balls 91 by promoting the rolling of the core balls 91, the bottom surface 1p ( That is, the upper surface of the cathode 1n may be a certain rough surface. On the other hand, from the viewpoint of preventing damage to the surface of the core ball 91 or the surface of the plating layer caused by friction with the bottom surface 1p of the plating chamber 1m, the bottom surface 1p may be a smooth surface. Further, as shown in FIG. 3C, in order to stabilize the turning motion of the core ball 91 on the bottom surface 1p of the plating chamber 1m, the core ball 91 formed along the turning direction of the plating solution L is guided. An annular guide groove 4y is preferably formed on the bottom surface 1p.

  In FIG. 1, reference numeral 1o denotes an anode containing tin disposed on the upper part of the plating chamber 1m so as to be opposed to the cathode 1n. The anode 1o is fixed to the hermetic lid 1L via a support member 1r made of stainless steel, titanium, platinum-plated titanium, or the like so as to be positioned at a position where the anode 1o is immersed in the plating solution L that fills the plating chamber 1m. Is connected to the positive electrode.

  Here, the preferable aspect of an anode is demonstrated below. When many core balls 91 are plated, the sum of the surface areas of all the core balls 91 becomes very large. A constant current is passed between the large number of core balls 91 and the anode, and a predetermined current density (a value obtained by dividing the current value by the sum of the surface areas of the core balls 91) is ensured. In order to form a plating layer uniformly and efficiently, the lower surface of the anode 1o and the upper surface of the cathode 1n are arranged to face each other, and a circle is included so as to include the range C of the ball group 9 that swivels on the cathode 1n. It is preferable to form the anode 1o in a ring shape. Furthermore, as shown in FIG. 4A, which is a front cross-sectional view of the upper right portion of the main body 1a, by providing irregularities on the bottom surface of the anode 14o facing the cathode, the area corresponding to the surface area of the core ball 91 can be increased. It can be formed on the anode 14o. Moreover, when it is desired to increase the surface area of the anode, the anode portion 15o may be configured as shown in FIG. The anode portion 15o includes an anode configured by a large number of conductive particles 15y connected to a positive electrode of a DC power supply circuit, and a substantially annular ring that is fixed to the sealing lid 1L via a support member and accommodates the large number of conductive particles 15y. A conductive particle storage container 15x having a shape is included. The mesh-shaped conductive particle storage container 15x, preferably made of a non-conductive material such as a resin, has a large number of openings through which the conductive particles 15y do not pass and the plating solution can flow. On the other hand, it is disposed above the plating solution supply port 1f so as not to obstruct the flow of the supplied plating solution. The conductive particle storage container 15x may be made of a conductive material such as stainless steel, titanium, or platinum plated titanium. The conductive particles 15y stored in the conductive particle storage container 15x are appropriately selected depending on the material to be plated on the core ball. For example, when tin is plated on the core ball, particles made of tin are selected. According to the anode portion 15o of this embodiment, since the anode is constituted by a large number of conductive particles 15y, it is possible to form an anode having a large surface area while being compact as compared with the case of the flat plate-like anode. The surface area of the anode can be freely adjusted by adjusting the individual size of 15y and the number of pieces accommodated.

  In FIG. 1, reference numeral 1 i denotes a vibration means arranged on the bottom side of the container 1 k. The vibration means 1i incorporated as a preferred embodiment of the plating apparatus according to the present invention is specifically a vibration means for applying vibration to the container 1k at a predetermined frequency. The vibration causes adhesion between the core balls 91 and the bottom surface 1p. The core ball 91 is prevented from adhering and the adhering core ball 91 is separated to prevent the core ball 91 from agglomerating.

  Reference numeral 1s is a magnetic force generating means disposed below the plating tank 1j. The magnetic force generating means 1s is an effective component when the core ball 91 has magnetism or when the plating layer covered with the core ball 91 has magnetism such as Ni or Fe, and the core ball 91 or the plating layer is formed. The core ball 91 is attracted downward by a magnetic force and is swung while being brought into contact with the bottom surface 1p of the plating chamber 1m (the top surface of the cathode 1n). The magnetic force generating means 1s may be provided on the lower outer periphery of the plating tank 1j. Further, in order to hold the ball group 9 in the turning area C and prevent the core balls 91 from being dispersed, the magnetic force generating means 1s is a substantially annular permanent magnet having a size corresponding to the turning range C. It is preferable to comprise by these.

  The operation of the plating apparatus 1 will be described. First, it is a preparation process. In the preparation step, the sealing lid 1L is opened, a predetermined number of core balls 91 are placed on the bottom surface 1p of the plating chamber 1m (the top surface of the cathode 1n), and the plating solution L is stored in the plating solution storage tank of the plating solution circulation means 1b. To do. In addition, as the core ball | bowl 91, what used the pickling process and cleaned the surface may be used, and also the thing which formed the nickel plating layer as a base layer on the surface as needed may be used. The plating solution for solder plating is, for example, the trade name “DAIN TINSIL SBB 2” manufactured by Daiwa Kasei Co., Ltd. having a Sn—Ag—Cu based liquid composition, the product name “SOLDERON BP SAC5000” manufactured by Rohm & Haas, etc. Additives can be added to a known plating bath such as a borofluoride bath, for example, and used as appropriate. The particles constituting the ball group 9 are not limited to the core ball 91. For example, as a stirring accelerator for promoting the stirring of the ball group 9, for example, conductive dummy balls mainly made of solder or steel, resin, ceramics, etc. An appropriate amount of a non-conductive dummy ball as a main component may be added.

  After closing the sealing lid 1L and making the plating chamber 1m into a sealed space, the plating apparatus 1 is operated. The plating apparatus 1 operates the plating solution circulating means 1b to supply the plating solution L at a predetermined flow rate to the plating chamber 1m through the plating solution supply pipe 1e. When the plating chamber 1m is filled with the plating solution L, the plating solution L turns along the peripheral wall surface 1q of the plating chamber 1m and turns into a swirling flow a that flows spirally along the inclination of the peripheral wall surface 1q toward the bottom surface 1p. . Since the flow of the plating solution L is unstable at the initial stage of supplying the plating solution L, the core ball 91 may flow out of the plating chamber 1m due to the unstable flow of the plating solution L. In order to prevent the core ball 91 from flowing out, it is preferable to fill the plating chamber 1m in advance with the plating solution L in the preparation step and then supply the plating solution L to the plating chamber 1m. In addition, it is preferable to reduce the flow rate of the plating solution L in the initial stage of supplying the plating solution L and gradually increase it to a predetermined flow rate.

  The plating liquid L swirling down the plating chamber 1m along the circumferential wall surface 1q of the plating chamber 1m having a truncated cone shape which is reduced in diameter toward the bottom increases in swirling speed as it approaches the bottom surface 1p and reaches the bottom surface 1p. The swirl flow a of the plating solution L that has reached the bottom surface 1p causes the ball group 9 in contact with the bottom surface 1p to swivel while pressing against the bottom surface 1p. Here, since the core ball 91 included in the ball group 9 is in contact with the bottom surface 1p, that is, the upper surface of the cathode 1n connected to the negative electrode of the DC power supply circuit 1h, the core ball 91 is plated with the anode 1o, A plating layer is formed on the surface. Since the plating solution L that has reached the bottom surface 1p of the plating chamber 1m becomes an upward flow b at the center of the bottom surface 1p and is discharged from the plating solution discharge pipe 1c through the plating solution discharge port 1d and returns to the plating solution circulation means 1b. The fresh plating solution L is supplied to the plating chamber 1m, and the state of the plating solution L in the plating chamber 1m can always be kept constant. As a result, a plating layer having a uniform thickness is formed on the surface of the core ball 91. The If the plating solution L is sucked through the plating solution discharge pipe 1c after the plating chamber 1m is filled with the plating solution L, the swirling flow of the plating solution L is further rectified and the swiveling motion of the core ball 91 is performed. Is desirable because it stabilizes.

  Since the core ball 91 that rotates while contacting the bottom surface 1p of the plating chamber 1m rolls on the bottom surface 1p and collides so that the core balls 91 rub against each other, the core balls 91 are difficult to adhere to each other. Aggregation of 91 is prevented, and the opportunity for the surface of the core ball 91 to come into contact with the bottom surface 1p by rolling is uniform, so that a plating layer having a uniform thickness is formed. Here, in the process of the plating process, it is estimated that the plating layer is formed on the surface of the core ball 91 gradually every time the cathode 1n is touched directly or indirectly through another core ball 91. Therefore, in the initial stage of the plating process, the plating layer is formed only on a part of the surface. In the case where the rolling of the core ball 91 is not sufficient, as shown in FIG. 14A, there may be formed a confetti-like Cu core ball in which the protruding plating layer m is covered with the core ball 91. It was. It is assumed that the protruding portion of the plating layer is a result of the selective formation of the plating layer starting from the plating layer formed on a part of the surface of the core ball 91 in the initial stage. However, as shown in FIG. 14B, the plated layer formed on a part of the surface of the core ball 91a by sufficiently rolling the core ball 91 and causing the core balls 91 to rub against each other. The smoothing effect of the surface of the plating layer, in which m1 is rubbed with another rolling core ball 91b and spread, prevents the plating layer from being selectively formed on a part of the surface. It is possible to form a plating layer that is extremely smooth and has a uniform thickness with few voids inside the plating layer. A Cu core ball having such a plated layer and extremely high sphericity is particularly suitable when used as a connection member for flip chip.

  In addition, when the core ball 91 is supplied to the plating chamber 1m using the core ball supply means 1g shown in FIG. 1, the core ball 91 is swung by the swirling and flowing plating solution L, and is applied to the peripheral wall surface 1q by centrifugal force. It descends while being pressed and descends to the bottom surface 1p of the plating chamber 1m, where it continues a stable turning motion.

  In the above state, the core ball 91 is plated for a predetermined time to form a Cu core ball having a solder plating layer having a predetermined thickness. The plating solution circulating pump and the flow rate adjusting valve of the plating solution circulating means 1b are adjusted as appropriate so that the flow rate and flow rate of the plating solution L supplied during the plating process are changed with time, or the vibrating means is supplied via the container 1k. If vibration is applied to the ball group 91 in 1i, it is advantageous from the viewpoint of preventing aggregation of the core balls 91.

  A further preferred embodiment of the plating apparatus 1 will be described with reference to FIGS. 5 and 6, the same components as those of the plating apparatus 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The plating apparatus 5 shown in FIG. 5 arranges the plating solution discharge pipe 5c so as to pass through the central portion of the sealing lid 1L and protrude into the plating chamber 1m, and the plating solution discharge port 5d is plated in the axial direction. An intermediate portion of the chamber 1m, specifically, the plating solution discharge port 5d is positioned below the plating solution supply port 1f, and the plating solution discharge pipe 5c can be moved along the axial direction as indicated by an arrow d. This is the embodiment. As shown in FIG. 5, when the anode 5o is disposed on the outer peripheral surface of the plating solution discharge pipe 5c, it is desirable to dispose the anode 5o so as not to protrude from the outer peripheral surface of the plating solution discharge tube 5c. According to the plating apparatus 5, since the plating solution discharge port 5d is close to the bottom surface 1p of the plating chamber 1m, the rising flow b of the plating solution L is discharged near the bottom surface 1p, and the rising flow b is swirled a. And the turning motion of the core ball 91 on the bottom surface 1p can be stabilized. Further, in the initial stage of supplying the plating solution L, the protruding length of the plating solution discharge pipe 5c from the sealing lid 1L is shortened until the swirling flow a in the plating chamber 1m is stabilized. The plating process is completed from the stage before the plating process in which the plating liquid L is introduced into the plating chamber 1m by moving the liquid discharge pipe 5c downward to increase the protruding length from the sealing lid 1L and positioning it at a predetermined position. Until then, the core ball 91 can be prevented from flowing out of the plating chamber 1 m. In the case of a plating apparatus having a structure for rectifying the plating solution that swirls and flows in the plating chamber and a structure for supplying the core ball to the plating chamber, as in the plating apparatus of the second to fourth aspects described later, The plating solution discharge pipe 5c may be fixed to the sealing lid 1L so that the plating solution discharge port 5d is disposed in the vicinity of the upper portion of the bottom surface 1p as shown in the drawing without moving in the vertical direction.

  The plating apparatus shown in FIG. 6 (a) is a mode in which a bottom surface 6p (upper surface of the cathode 6n) is formed in the plating chamber 1m in a conical shape so that the center portion is higher than the peripheral portion in the radial direction. According to the plating apparatus of this aspect, the ball group 9 is stably swung around the peripheral portion having a low height of the bottom surface 6p, and the concentration of the ball on the bottom surface 6p can be improved. Note that, as shown in FIG. 5B, the bottom surface 7p (the upper surface of the cathode 7n) having the columnar projection 7y is formed in the plating chamber 1m so that the central portion is higher than the peripheral portion in the radial direction. In this case, it is desirable to form a tapered surface on the upper peripheral edge of the protrusion 7y so as not to inhibit the flow of the plating solution L.

[Second Embodiment]
Hereinafter, the plating apparatus according to the second embodiment will be described with reference to FIGS. 7 and 8, the same components as those of the plating apparatus 1 of the first embodiment and the plating apparatus 5 of the preferred embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted (hereinafter referred to as the third embodiment). (The same applies to the plating apparatus of the fifth aspect.)

  As shown in FIG. 7 (a), the plating apparatus 8 of the second aspect is different from the plating apparatus 1 of the first aspect in that it has guide means 8v in the plating chamber 1m formed in the same manner as the first aspect. doing. The guiding means 8v in FIG. 7A is configured to guide the plating solution L supplied through the plating solution supply port 1f toward the bottom surface 1p of the plating chamber 1m. In other words, the guide means 8v is a guide made of a non-conductive material in which a spiral is formed that extends in the direction along the streamline a of the plating solution L that swirls along the peripheral wall surface 1q of the plating chamber 1m and flows down toward the bottom surface 1p. It is the board 8w. A guide plate 8w in which an upper portion 8x is disposed below the plating solution supply port 1f and a lower portion 8y is disposed with a predetermined gap from the bottom surface 1p of the plating chamber 1m passes through the plating solution discharge pipe 5c penetrating the sealing lid 1L in the vertical direction. The outer peripheral surface is in close contact with the peripheral wall surface 1q while surrounding the center. In order to smoothly discharge the plating solution L from the plating chamber 1m, it is preferable that the lower end of the guide means 8x is above the plating solution discharge port.

  According to the guide plate 8w, the plating solution L supplied from the plating solution supply port 1f is spirally distributed by the guide plate 8w, the outer peripheral surface of the plating solution discharge pipe 5c, and the peripheral wall surface 1q of the plating chamber 1m. As indicated by a broken line a in the passage 8z, the fluid flows from above to below and is guided to the bottom surface 1p of the plating chamber 1m. Here, the guide plate 8w is spirally formed along the streamline a of the plating solution L supplied from the plating solution supply port 1f and swirling down, and the circulation passage 8z is formed as a single passage. Therefore, the rectified plating liquid L is generated without causing turbulent flow in the swirling plating liquid L due to mutual interference between the plating liquid L supplied from the plating liquid supply port 1f and the flowing plating liquid L. Will reach the bottom surface 1p. Further, as indicated by reference numeral b2 in the figure, a part of the flow b of the plating liquid L directed to the plating liquid discharge port as an upward flow is discharged from the plating liquid discharge pipe 5c and exists outside the plating liquid discharge pipe 5c. Even in this case, since the flow is blocked by the lower portion 8y of the guide plate 8w, the flow a of the plating solution L flowing down is not disturbed. As a result, the swivel motion of the ball group on the bottom surface 1p is stabilized, and a Cu core ball having a uniform plating layer can be formed.

  In addition, like the plating apparatus 16 shown in FIG. 7B, which is a modified example of the plating apparatus 8, the guide plate 16w is arranged on the outer peripheral surface of the plating liquid discharge pipe 5c in such a manner that the plating liquid L turns around the peripheral wall surface 1q. It may be configured such that a constant gap 16z is formed between them and placed in the plating chamber 1m.

  The plating apparatus 10 shown in FIG. 8 is another example of the plating apparatus of the second aspect, and has a guide body 10w as the guide means 10v. A guide body 10w made of a substantially frustoconical non-conductive material having a bottom surface 10z has an outer peripheral surface 10x that follows the peripheral wall surface 1q of a substantially conical plating chamber 1m having a diameter reduced toward the bottom surface 1p. The guide body 10w whose upper part is joined to the sealing lid 1L has a plating solution discharge pipe 5c that is fixed to the sealing lid 1L and extends in the vertical direction at the center, and the outer peripheral surface 10x surrounds the plating solution discharge pipe 5c. Yes. And the guide body 10w is arrange | positioned in the plating chamber 1m so that the outer peripheral surface 10x may oppose the surrounding wall surface 1q of the plating chamber 1m through the gap | interval 10y of the fixed dimension g in a horizontal direction. Further, in the vertical direction, the ball group 9 is provided with a region in which the ball group 9 can pivot on the bottom surface 1p of the plating chamber 1m, so that the bottom surface 10z of the guide body 10w has a predetermined gap with respect to the bottom surface 1p of the plating chamber 1m. Is arranged. In addition, in the plating apparatus 10 of this aspect, the anode 10o mainly composed of tin is provided on the bottom surface 10z of the guide body 10w.

  By arranging the guide body 10w as the guide means at the center of the plating chamber 1m, the same action as the guide plate 8w can be achieved. That is, the plating liquid L supplied from the plating liquid supply port 1f is directed from above to below as indicated by a broken line a in a gap 10y formed by the outer peripheral surface 10x of the guide body 10w and the peripheral wall surface 1q of the plating chamber 1m. The swirling flow then guides to the bottom surface 1p of the plating chamber 1m. Since the plating liquid L that swirls flows in a relatively narrow gap 10y surrounded by the outer peripheral surface 10x of the guide body 10w and the peripheral wall surface 1q of the plating chamber 1m, the plating supplied from the plating liquid supply port 1f is performed. The rectified plating solution L reaches the bottom surface 1p without causing turbulent flow in the swirling plating solution L due to mutual interference between the solution L and the flowing plating solution L. Further, as shown as b2 in the figure, even when a part of the flow b of the plating solution L toward the plating solution discharge port 5d as an upward flow is discharged from the plating solution discharge pipe 5c, it exists outside the plating solution discharge pipe 5c. Since the flow is interrupted by the bottom surface 10z of the guide body 10w, the flow a of the plating solution L flowing down is not disturbed. As a result, the swivel motion of the ball group on the bottom surface 1p is stabilized, and a Cu core ball having a uniform plating layer can be formed. The guide plate 8w may be incorporated in the gap 10y between the guide body 10w and the peripheral wall surface 1q.

  Moreover, the anode part demonstrated with reference to FIG.4 (b) can be integrated in the plating apparatus which has the said guide body. That is, as shown in the plating apparatus 21 in FIG. 8 (b), the guide body 21w made of a mesh-like non-conductive material also serves as a conductive particle storage container of the anode portion, and the anode is placed inside the guide body 21w. A large number of constituent conductive particles 21o are accommodated, and the conductive particles 21o do not pass therethrough and have a large number of minute openings through which the plating solution can be circulated slightly. Note that the opening provided in the guide body 21w is smaller than the size of the conductive particles 21o and is extremely small and has high resistance when the plating solution flows, so that the upward flow of the plating solution passes through the guide body 21w while maintaining the flow velocity. However, it does not disturb the swirling flow of the plating solution.

[Third embodiment]
Hereinafter, the plating apparatus of the third aspect and its modification will be described with reference to FIG. The plating apparatus of the third aspect is different from the plating apparatus 1 of the first aspect in that a rectifying means is provided in the plating chamber 1m formed in the same manner as the first aspect. Hereinafter, various aspects of the rectifying means will be described.

  The rectifying means 17v in FIG. 9 (a) is a non-conductive that rectifies the flow of the plating solution L that is supplied from the plating solution supply port 1f and swirls along the peripheral wall surface 1q of the plating chamber 1m in a certain direction. This is a plate-like member 17w made of a conductive material. The plate-like member 17w formed with a spiral extending in the direction along the flow line of the plating solution L swirling along the peripheral wall surface 1q of the plating chamber 1m has an upper portion 17x below the plating solution supply port 1f and a lower portion 17y. Are arranged so that the outer peripheral surface is in close contact with the peripheral wall surface 1q with a predetermined gap from the bottom surface 1p of the plating chamber 1m. According to the plate-like member 17w, the plating solution L supplied from the plating solution supply port 1f so as to turn along the peripheral wall surface 1p of the plating chamber 1m is rectified by the plate-like member 17w. A ball group which is stably maintained and reaches the bottom surface 1p and is in contact with the bottom surface 1p of the plating chamber 1m is swung while being pressed against the bottom surface 1p.

  As shown in FIG. 9B, which is a modified example of the rectifying means 17v, a plurality of fin-like plate members 18q, 18r, and 18s are plated in the same manner as the plate member 17w through the gap 18t. The rectifying means 18v may be configured by being arranged in a line along a streamline of the swirl flow of the liquid L in a line. Moreover, as shown in FIG.9 (c), while arrange | positioning the several plate-shaped members 19q-19r in a line along the streamline of the swirl | vortex flow of the plating liquid L, it arrange | positions below the plate-shaped members 19q-19r. The rectifying means 19v having two rows of plate members may be configured by arranging the plate members 19s to 19t in a staggered pattern so as to fill the gaps 19u between the plate members 19q to 19r.

[Fourth Embodiment]
Hereinafter, the plating apparatus of the fourth aspect and its modification will be described with reference to FIGS. The plating apparatus according to the fourth aspect is different from the plating apparatus according to the first aspect in that it includes supply means for supplying the ball group to the plating chamber and recovery means for recovering the ball group. Hereinafter, the plating apparatus of the fourth aspect will be described focusing on the supply means and the recovery means. Note that the supply means and the recovery means may each be incorporated in the plating apparatus independently.

  First, the supply means will be described. FIG. 10 (a) is a front cross-sectional view, and FIG. 10 (b) is a plan view showing a state in which the sealing lid 1L is removed from the container 1k of the same figure. As shown in FIG. A storage portion 11r for storing a large number of core balls 92 to be supplied to the housing, and a plating solution inflow pipe 11u and a ball supply pipe 11v each having one end connected to the storage portion 11r and the other end connected to the plating tank 1j. doing. In FIG. 10A, the line above the AA line is a view as seen from the direction of the arrow B viewed from above the center line E of the plating tank 1j shown in FIG. 10B, and the line below the line AA is the center line E. It is C arrow line view which looked at the lower side.

  The storage unit 11r includes a container 11s that can store a large number of core balls 92, and a lid 11t that closes an upper opening of the container 11s, and supplies the core balls 92 to the container 11s by opening and closing the cover 11t. To do. One end of a plating solution inflow pipe 11u is connected to the side wall of the storage portion 11r via a valve 11w, and the other end of the plating solution inflow pipe 11u has an opening (plating solution inflow port) 11y formed in a plating chamber 1m. Is connected to the plating tank 1j. Here, the plating solution inflow pipe 11u has an axial center substantially on the same line as the plating solution supply pipe 1e, that is, above the plating tank 1j and along the tangential direction of the peripheral wall 1q of the plating chamber 1m. The inflow port 11y is arranged so as to receive the flow a of the plating solution that swirls. As a result, since the plating solution inlet 11y and the plating solution supply port 1f are opposed to each other through the center line F of the plating chamber 1m in plan view, as shown by the broken line a in FIG. The plating solution supplied to swirl along 1q flows into the plating solution inflow pipe 11u through the plating solution inlet 11y.

  One end of a ball supply pipe 11v is connected to the bottom of the storage section 11r, and the other end of the ball supply pipe 11v is connected to the plating tank 1j so that its opening (ball supply port) 11z opens to the bottom of the plating chamber 1m. It is connected. Here, as shown in FIG. 10 (b), the ball supply pipe 11v is located at a position opposite to the plating solution inflow pipe 11u through the center line E of the plating chamber 1m in a plan view, and its axis is the center of the plating chamber 1m. Along the tangential direction, the ball supply port 11z is disposed along the flow a of the plating solution that rotates. Accordingly, the core ball 92 can be supplied so as to smoothly ride on the plating solution flow a supplied from the plating solution supply port 1f and flowing down along the peripheral wall surface 1q and swirling on the bottom surface 1p. In the figure, reference numeral 11x denotes a gate valve for holding the core ball 92 to be supplied in the storage portion 11r. This gate valve 11x is a suitable configuration provided for automatically supplying the core ball 92 to the plating chamber 1m, and is not necessarily required when supplying the core ball manually.

  Next, the collection means 11a of the ball group 9 including the core ball 91 after the plating process will be described. The cathode 11n of this aspect forms a part of the constituent elements of the recovery means 11a, and is slidably fitted to the inner surface of the cylindrical portion 11L formed at the lower part of the container 1k, and forms a disc shape. An O-ring (not shown) is provided on the outer peripheral surface to prevent leakage of the plating solution. An opening (ball recovery port) 11c at one end of a ball collection tube 11b that collects a group of balls including a core ball on which a plating layer is formed opens on the inner surface of the cylindrical portion 11L, and the ball collection tube 11b. Is connected to the collection container 11e. As shown in FIG. 10 (b), the ball collection tube 11b is located at a position opposite to the ball supply tube 11v through the center line F of the plating chamber 1m in plan view, and its axis is tangent to the plating chamber 1m. Along the direction, the ball collection port 11c is arranged so as to receive the flow a of the plating solution that turns.

  Here, the cathode 11n is moved in the cylindrical portion 11L in the vertical direction indicated by the symbol h by the vertical driving portion 11d such as an air cylinder, and is located at the lower end edge of the peripheral wall 1q of the plating chamber 1m at the rising end position. The upper surface 11p (which also serves as the bottom surface of the plating chamber 1m) is in contact, and the ball collection port 11c is closed at the outer peripheral surface, and the ball collection port 11c is opened at the lower end. In the plating apparatus 11 of this aspect, the cathode 11n is used like a valve, and the ball recovery port 11c is opened and closed by moving the cathode 11n up and down. However, the plating apparatus 1 of the first aspect performs plating. A cathode is fixed to the bottom of the chamber, a ball collecting tube is connected to the plating tank via a valve, and a collecting means is configured so that the ball collecting port opens directly to the plating chamber, and the core ball is collected by opening and closing the valve. It may be. In this case, the ball collection port is preferably disposed above the bottom surface of the plating chamber so as not to hinder the movement of the core ball that swirls around the bottom surface of the plating chamber.

  The operation of the plating apparatus 11 including the supply means 11q and the recovery means 11a will be described with reference to FIG. The lid 11t of the storage portion 11r shown in FIG. 11A is opened to supply a predetermined number of core balls 92 to the container 11s, and then the lid 11t is closed. At this time, the valve 11w and the gate valve 11x are closed. Further, the cathode 11n raised by the vertical drive unit 11d is at the position of the rising end, and the ball collection port 11c is closed.

  Next, the plating apparatus 11 is operated to supply the plating liquid L from the plating liquid supply port 1f. When the plating chamber 1m is filled with the plating solution L after a certain time has elapsed, as shown in FIG. 11 (a), the plating solution L turns along the peripheral wall surface 1q of the plating chamber 1m and is inclined to the peripheral wall surface 1q. A stable swirling flow a flowing down in a spiral toward the bottom surface 11p is formed.

  After the plating solution L is supplied and after a certain time has passed and the flow state of the plating solution L in the plating chamber 1m is stabilized, the plating apparatus 11 opens the valve 11w, and the plating that swirls and flows as indicated by the arrow e in FIG. A part of the liquid L is caused to flow from the plating liquid inflow pipe 11u into the storage portion 11r through the plating liquid inlet 11y, and the gate valve 11x is opened. Then, the core ball 92 accommodated in the accommodating portion 11r is pushed out of the accommodating portion 11r by the flowing plating solution L, flows along with the plating solution L through the conduit of the ball supply tube 11v, and supplies the ball as indicated by an arrow f. It is discharged from the port 11z and supplied to the plating chamber 1m. The plating apparatus 11 closes the valve 11w and the gate valve 11x after all the core balls 92 are supplied to the plating chamber 1m. Here, since the ball supply pipe 11v is arranged as described above, the core ball 92 supplied from the ball supply port 11z rides on the swirling flow a of the plating solution L and then smoothly moves on the bottom surface 11p of the plating chamber 1m. Rotating movement is performed and plating is performed. As described above, the core ball 92 is supplied to the plating chamber 1m after a certain period of time has elapsed since the plating solution L was supplied to the plating chamber 1m, and the plating solution in the plating chamber is stabilized. The core ball 91 hardly flows out and can be plated on the core ball 91 with a high yield.

  When manually supplying the core ball 92, the gate valve 11x is not provided in the path of the ball supply pipe 11v, and after the flow state of the plating solution L is stabilized, the valve 11w is opened and the plating solution is introduced. A predetermined number of core balls 92 may be supplied to the storage portion 11r after the plating solution L is circulated through the path of the tube 11u, the storage portion 11r, and the ball supply tube 11v.

  Next, as shown in FIG. 11 (c), when the plating apparatus 11 lowers the cathode 11n to the lower end by the vertical drive part 11d and opens the ball recovery port 11c, the ball including the core ball 91 on which the plating layer is formed is formed. The group 9 flows into the ball collection tube 11b through the ball collection port 11c as indicated by the arrow i, and is then collected in the collection container 11e. If a valve is provided in the plating solution discharge pipe 5c and the valve is throttled as the cathode 11n descends, a large portion of the plating solution L is discharged through the ball collection tube 11b. Group 9 can be recovered.

  A plating apparatus 12 shown in FIG. 12 is another example of the plating apparatus of the fourth aspect, and has a supply means 12q provided on the path of the plating solution supply pipe 1e. That is, one end of the plating solution inflow pipe 11u of the supply means 12q is connected to the upstream side of the plating solution supply pipe 1e, and one end of the ball supply pipe 11v is connected to the downstream side of the plating solution supply pipe 1e. The end is configured to be connected to the storage portion 11r via the valve 11w and the gate valve 11x. According to the supply means 12q, when the valve 11w and the gate valve 11x are opened after the flow state of the plating liquid L in the plating chamber 1m is stabilized, a part of the plating liquid L flowing through the plating liquid supply pipe 1e is allowed to flow into the plating liquid. It flows into the storage portion 11r through the tube 11u. Then, the core ball 92 accommodated in the accommodating portion 11r is pushed out by the flowing plating solution L, flows into the plating solution supply pipe 1e through the ball supply tube 11v, and is supplied together with the plating solution L from the plating solution supply port 1f to the plating chamber. 1 m will be supplied. In order to smoothly distribute the plating solution in the supply means 12q, the upstream inner diameter of the plating solution supply pipe 1e to which the plating solution inflow pipe 11u is connected is increased, and the downstream side to which the ball supply pipe 11v is connected. It is desirable to make the inner diameter of the tube thinner than the upstream side. Furthermore, in order to allow the core ball 92 to flow into the plating solution supply pipe 1e without staying in the supply means 12q, the space between the bottom surface of the storage portion 11r and the bottom surfaces of the plating solution inflow tube 11u and the ball supply tube 11v. It is preferable that there is no step in the plate.

[Fifth Embodiment]
Hereinafter, the plating apparatus of the fifth aspect will be described with reference to FIG. FIG. 13 (a) is a front sectional view showing a schematic configuration of a plating apparatus which is an example of the fifth embodiment, FIG. 13 (b) is a view as viewed from arrow D in FIG. 13 (a), and FIG. The front sectional view showing a schematic configuration of another example of the plating apparatus of the fifth aspect, FIG. 9 (d) is a view taken in the direction of arrow E in FIG.

  In the plating apparatus according to any one of the first to fourth aspects, a substantially frustoconical shape standing on the periphery of the bottom surface so as to reduce the diameter toward the bottom surface of the circular bottom surface as the bottom surface of the plating chamber that can circulate while contacting with the core ball A plating chamber with a peripheral wall of the plate, a plating solution supply pipe in which the axis is horizontally arranged so that the plating solution supply port opens along the tangential direction of the plating chamber having a circular cross section, and arranged along the axis of the plating chamber Although the plating apparatus having each component of the plating solution discharge pipe thus described has been described, the present invention is not limited to these desirable aspects, and can also be realized by the plating apparatus of the fifth aspect.

  As shown in FIG. 13 (b), the plating apparatus 13 which is an example of the fifth aspect has a substantially elliptical bottom surface 13p as a bottom surface on which the core ball 91 can circulate, and has a circumference standing on the periphery of the bottom surface 13p. The plating chamber 13m is formed so that the wall surface 13q has the same cross section in the vertical direction, that is, a straight tubular shape. Further, the plating solution supply pipe 13e for supplying the plating solution L to the plating chamber 13m generates a flow of the plating solution L that swirls down along the peripheral wall surface 13q. Therefore, the plating tank 1j with its axis oriented downward. It is connected to the. If the plating solution supply pipe 13e is connected to the plating tank 1j through a joint or the like whose attachment angle with respect to the peripheral wall surface 13q can be freely set, the plating solution can be selected according to the size and quantity of core balls to be plated. This is preferable because the angle at which L swirls can be set as appropriate. Further, the plating solution discharge pipe 1c for discharging the plating solution L from the plating chamber 13m is hermetically sealed in the same manner as the plating apparatus 1 of the first mode in order to smoothly discharge the rising flow b of the plating solution L from the plating chamber 13m. Although it is preferable to be provided at the center of 1L, the arrangement of the plating solution discharge pipe is not limited to this, and the plating solution is provided from the outer periphery of the sealing lid 1L like the plating solution discharge pipe 13c shown by the broken line in the drawing. The plating solution L overflowing from the chamber 13m may be discharged.

  The operation of the plating apparatus 13 will be described. The ball group 9 is placed on the bottom surface 13p of the plating chamber 13m, and then the sealing lid 1L is closed to make the plating chamber 13m a sealed space, and the plating apparatus 13 is operated. The plating apparatus 13 supplies the plating solution L to the plating chamber 13m through the plating solution supply pipe 13e. When the plating chamber 13m is filled with the plating solution L, the plating solution L supplied from the plating solution supply pipe 13e arranged as described above swirls in a spiral manner along the peripheral wall surface 13q of the plating chamber 13m. a. The plating solution L that has reached the bottom surface 13p while swirling down swirls while pressing the ball group 9 in contact with the bottom surface 13p against the bottom surface 13p, thereby forming a plating layer on the surface of the core ball 91. Similarly to the plating apparatus 1 of the first aspect, the core ball 91 that rotates while being in contact with the bottom surface 13p of the plating chamber 13m rolls on the bottom surface 13p. This prevents the chance that the surface of the core ball 91 touches the bottom surface 13p due to rolling, so that a plating layer having a uniform thickness is formed. Since the plating solution L supplied to the plating chamber 13m is discharged from the plating solution discharge pipe 1c, the fresh plating solution L is always supplied to the plating chamber 13m, so that a plating layer having a uniform thickness is formed.

  The plating apparatus 20 which is another example of the fifth mode shown in FIGS. 13C and 13D is erected along an annular bottom surface 20p as a bottom surface on which the core ball 91 can circulate, and an outer peripheral edge of the bottom surface 20p. The plating chamber 20m has an outer peripheral wall surface 20q and an inner peripheral wall surface 20x erected along the inner peripheral edge, and the plating chamber 20m is formed so that the cross section of the plating chamber 20m is the same in the vertical direction. In the plating apparatus 20 as well, a plating layer is formed on the core ball 91 by basically the same operation as the plating apparatus 13, but the cathode 20n itself constituting the bottom surface 20p is formed in an annular shape. As in the case of the cathode structure described with reference to 2 (b) and 2 (c), it is possible to achieve an effect that the plating efficiency can be improved.

[Example]
The plating apparatus 1 according to the first aspect is charged with 500,000 core balls having a diameter of 50 μm, plated at a target value of 20 μm under a predetermined condition by the above-described method, and an Sn—Ag—Cu based plating layer A Cu core ball with a formed thereon was obtained. FIG. 15 shows the distribution of diameter and roundness measured by extracting 600 specimens from 500,000 core balls and Cu core balls. Moreover, the external appearance photograph and cross-sectional photograph of Cu core ball at the time of plating with the plating apparatus 1 of the 1st aspect, and Cu core ball at the time of plating with the plating apparatus of prior art document 1 are shown in FIG.

  As shown in FIG. 15, the average value of the diameter of the Cu core ball was approximately 90 μm with respect to the average value of the core ball diameter of 50.4 μm, and a plating layer having a thickness of 20 μm, which is the target value, was formed. Moreover, the roundness of the Cu core ball was 0.9965, and a Cu core ball having a high roundness exceeding the roundness of the core ball as the base particle of 0.9960 was formed. In addition, the standard deviations of the diameter and roundness of the Cu core ball are 1.7776 and 0.0018, respectively, which are lower than the core balls 2.108 and 0.0075, and have a small variation in diameter and roundness. I was able to get a core ball.

  As shown in FIGS. 16 (a) and 16 (b), the Cu core ball on which the plating layer is formed by the plating apparatus 1 of the first aspect has a very smooth and smooth surface, and the plating layer is formed on the surface of the core ball. Are uniformly formed, and no voids are formed inside the plating layer. On the other hand, as shown in FIGS. 3C and 3D, the Cu core ball on which the plating layer is formed by the plating apparatus of Prior Art Document 1 has irregularities that cause voids on the surface of the plating layer, It was confirmed that due to the unevenness, the roundness was low and the variation in diameter and roundness was large.

1 (5, 8, 10, 11, 12, 13, 16, 17, 18, 19, 20, 21, 22): Plating apparatus 1a (5a): Body 1j: Plating tank 1m (13m, 20m): Plating Chamber 1n (2n, 3n, 3m, 6n, 7n, 11n, 13n, 20n): Cathode 1o (5o, 10o, 14o, 15o): Anode 1b: Plating solution circulation means 1c (5c, 13c): Plating solution discharge pipe 1e (13e, 22e): plating solution supply pipe 1g (11q, 12q): supply means 1h: DC power supply circuit 1i: vibration means 1s: magnetism generation means 8v (10v, 16v): guide means 8w (16w): guide Plate 10w: Guide body 11a: Recovery means 17v (18v, 19v): Rectification means 17w (18w, 19w): Plate member 91: Core ball

Claims (20)

A device for plating base material particles having conductivity on the surface, the base particle comprising a bottom surface capable of rotating while contacting with the base material particle, and a peripheral wall surface erected along the periphery of the bottom surface. A plating tank having a plating chamber capable of storing a group and a plating solution; a supply port that opens upward from the bottom surface of the plating chamber; and a plating solution from the supply port so as to turn along the peripheral wall surface of the plating chamber. A plating solution supply pipe for supplying the plating solution, a plating solution discharge pipe having a discharge opening that opens into the plating chamber, a cathode that contacts the base material particles disposed on the bottom surface of the plating chamber, and is accommodated in the plating chamber. A plating apparatus comprising: an anode disposed at a position immersed in a plating solution; and a cathode and a power source connected to the anode. The bottom surface of the plating chamber has a circular shape, the peripheral wall surface of the plating chamber has a conical shape with a diameter reduced toward the bottom surface of the plating chamber, and the plating solution discharge pipe is disposed coaxially with the axis of the plating chamber. The plating apparatus according to claim 1.   The plating apparatus according to claim 2, wherein the discharge port is disposed below the supply port. The plating apparatus according to claim 2, wherein the plating solution discharge pipe is configured to be movable along an axial direction of the plating chamber. The said cathode is arrange | positioned in the substantially annular | circular shape at the peripheral part of the bottom face of the said plating chamber.
The plating apparatus in any one of. Bottom of the plating chamber, in its radial direction, the plating apparatus according to any one of claims 2 to 5 the central portion is formed so as to be higher relative to the peripheral portion. The anode, the plating apparatus according to any one of claims 1 to 6 comprising a large number of conductive particles that is connected to the power supply. Plating apparatus according to any one of claims 1 to 7 having a guide means for guiding toward the plating liquid supplied from the supply port of the plating liquid supply pipe on the bottom of the plating chamber to the plating chamber. The plating apparatus according to claim 8 , wherein the guide means is a guide plate provided in a spiral shape. The plating apparatus according to claim 8 , wherein the guide means is a guide body having an outer peripheral surface formed following the peripheral wall surface of the plating chamber and having a predetermined gap between the peripheral wall surface and the outer peripheral surface. The plating apparatus according to any one of claims 1 to 10 , wherein the plating chamber includes a rectifying unit that rectifies the plating solution supplied from a supply port of the plating solution supply pipe. The plating apparatus according to claim 11 , wherein the rectifying means is a plate-like member provided on a peripheral wall surface of the plating chamber. Plating apparatus according to any one of claims 1 to 12 is sucked configured to enable plating liquid from the discharge port of the plating liquid discharge pipe. The plating apparatus according to any one of claims 1 to 13 , wherein a flow rate or a flow rate of the plating solution supplied from the plating solution supply pipe is changed with time. On the bottom of the plating chamber, according to any of the plating solution supply to claim 1 guide groove formed along the turning direction of the supplied plating solution to guide the particles are formed from a pipe 14 Plating equipment. Plating apparatus according to any one of claims 1 to 15 having a vibrating means connected to the plating bath. 2. The apparatus according to claim 1, further comprising a magnetic force generating means disposed at a lower portion or a lower side portion of the plating chamber, wherein the base particles having soft magnetism are attracted to the bottom surface of the plating chamber by the magnetic force of the magnetic force generating means. The plating apparatus in any one of thru | or 16 . It is connected indirectly to the plating chamber directly or via the plating solution supply pipe, plating apparatus according to any one of claims 1 to 17 having a supply means for supplying the particles to the plating chamber. The supply means includes a storage unit that stores the particle group, and a base particle supply pipe that has one end connected to the storage unit and a peripheral wall surface of the plating chamber and the other end connected to the bottom surface side. , claim 18 having a plating liquid inlet pipe and the other end above the other end of the base particle supply pipe is connected to a peripheral wall surface of the plating chamber with one end connected to the housing part Plating equipment. Plating apparatus according to any one of claims 1 to 19 having a recovery means for recovering the particles accommodated in the plating chamber.